Insights into the Circular (re)Design of Medical Wearbale Sensors

Insights into the Circular (re)Design of Medical Wearable Sensors Insights into the Circular (re)Design of Medical Wearable Sensors MSc Graduation Thesis Integrated Product Design Delft University of Technology Faculty of Industrial Design Engineering Author Matthijs Bult 4446151 Supervisory Team Chair: Ruud van Heur Mentor: Tamara Hoveling Hi! You’re about to read my master’s thesis which I used to graduate within Integrated Product Design at the TU Delft. In my search for a thesis, I knew I wanted sustainability to play a central role. Throughout my studies, I had encounters with circular design, but I never got a chance to delve into it. This thesis provided me with the opportunity to explore circular product design and understand how we, as designers, can reduce our environmental impact by embracing the principles of the circular economy. I hold the belief that our field inherently contributes to polluting. After all, the products we create require manufacturing, materials, and eventually, end up as some form of waste. I also firmly believe that as product designers, we have a moral responsibility to design for a better world. This involves not only creating products that enrich people's lives but also products that contribute positively to the environment, to our environment. With this thesis, I hope to inspire you to apply circular design to your project. Let's work together towards a sustainable future! I•Preface 4 I want to thank my supervisors, Ruud and Tamara, for their continuous support throughout the thesis. I could always count on your honest feedback and your support when I needed it at the right times. I want to thank Hans and everyone at Philips for sharing their knowledge, perspectives and insights on the Healthdot and how it can be improved. Special thanks to Suzanne and the people at Games for Health for their valuable input on my concepts. A massive shoutout to my parents for putting me on this earth, feeding me and supporting me, for all the hours spent proofreading my work mere hours before the deadline is due. Finally, a big hug to all my friends from IO. Thank you for supporting me from day one, all the way up to this final moment. You lifted me when I was down, and pulled me out when I was stuck. I could not have gotten to this point without any of you. II•Acknowledgemetns 5 III•Glossary Circular Economy A system wherein the value of materials and resources is maintained indefinitely, further explained in Chapter 3. Circular Flows or Circular Loops Describes how a product cycles through a circular system Circularity A way of describing how good something fits in the circular economy. Cleaning Act of removing dirt and debris from inanimate object, but not disinfecting or sterilising. Criticality How critical it is that a device is, clean, disinfect or sterilised. Disinfection The process of reducing microorganisms from inanimate objects to safe levels E-waste Electronic products that have become obsolete and are viewed as a waste Impact Environmental impact of a product, often measured in Kg/CO2 Life Cycle Analysis (LCA) Assessment method to analyse the impact of a product Medical wearable sensor (MWS) Small medical product that wirelessly measures biosignals, also referred to as ‘sensor’ Original Equipment Manufacturer (OEM) An organisation that makes devices for other organisations. Sterilisation The process of killing all microorganisms from inanimate objects Sustainability Environmental sustainability, further defined in Section 3.1. 6 This thesis is executed within the context of the DiCE project: Digital health in Circular Economy (European Commission, n.d.). The European-funded project “aims to address the issue of increasing digital health waste” (WEEE Forum, 2023) and involves 20 different organisations, including the TU Delft and Philips. The project aims to guide the medical sector towards a more sustainable future. IV•Digital Health in Circular Economy 7 This thesis presents recommendations based on a case study focused on the circular redesign of the Philips Healthdot. The study addresses a knowledge gap by offering insights into the circular design for products like the Healthdot. The proposed redesign of the Healthdot’s system led to a substantial reduction of CO2 emissions, with potential for further improvements. Philips Healthdot The Philips Healthdot (Figure I) is a medical wearable sensor designed to wirelessly capture bio measurements and transmit them to hospitals. Once used, the sensor becomes inactive and is discarded as waste. While similar reusable sensors exist, only two were identified during research. Research Lterature research was conducted concerning the circular economy, its design strategies and business models. A comprehensive analysis of the Healthdot’s product journey was performed, complemented by a fast-track Life Cycle Analysis (LCA). The LCA revealed the high CO2 impact of its electronics, highlighting the importance of extending their usage. Based on the outcomes of these analyses, requirements and criteria were defined, which formed the foundations of the proposed solution. SecondSense The proposed solution, SecondSense, consists of two components: SenseFlow and SenseCab (Figure II & III). SenseFlow describes the sensor lifecycle within the system, while SenseCab enables easy reprocessing. In the SenseFlow system, used sensors are collected, cleaned, and placed in the SenseCab for data removal, disinfection and charging. Life Cycle Analysis A comparison between SecondSense and the original Healthdot was conducted using an LCA (see Figure IV). SecondSense shows reductions in CO2 emissions after only three uses, with 45% and 60% reductions V•Executive Summary Figure I: Philips Healthdot (Philips, n.d.-d) 8 Product Use Internal use External use Reprocessing Factory Reuse Phase SecondSense Use Phase Preparation Figure II: SeconSense System 9 1 • Problem Definition Healthcare is an important part of our daily lives; from small inconveniences to life-saving procedures, we all have been in touch with the healthcare system at some point. Healthcare is here to protect us from harm and to heal us, but in doing so it creates an enormous amount of waste that is hurting us and our planet in the long run. Healthcare sector has, in fact, a large impact on our ecosystem. To illustrate, 4,4% of all global emissions come from the healthcare sector (Health Care Without Harm, 2019), and in the Netherlands, this number rises to 7% (Gupta Strategists, 2019). When it comes to waste, the average European hospital generates 2,4kg of waste per patient per day (Singh et al., 2022). While these numbers are high, the sector is actively trying to become more circular, with initiatives such as “Samen naar een circulair ziekenhuis” [To a circular hospital together] (de Zorgambassade, 2022). With the healthcare industry becoming smarter and more digitized, you can also expect the amount of electronic waste to rise. According to the European Parliament, e-waste is one of the fastest-growing waste streams while less than 40% of this waste is recycled (European Parliament, 2020). The global average is even lower, with only 17% being collected and recycled properly (Forti et al., n.d.). General e-waste products often end up stockpiled at home and too often end up at the incinerator (Miliute-Plepiene, 2021). E-waste is a dangerous waste stream as it contains toxic and harmful materials that are detrimental to both humans and the environment (Lin et al., 2022; Ogunseitan, 2022; Wirtu & Tucho, 2022). Although medical products serve to make us better, unfortunately, they are no exception to this waste stream (Lefebvre et al., 2011; Ogunseitan, 2022). Healthdot In 2021, Philips introduced the Healthdot (Figure 1.1): a small Medical Wearable Sensor (MWS) that measures the patient’s heart rate and uploads this to the hospital, so that patients can be monitored remotely from their own home (Philips, n.d.-d). With the introduction of the Healthdot, Philips aims to improve healthcare by allowing transitional care, as it frees up bed space 16 Figure 1.1: Philips Healthdot being applied (Philips, n.d.-b) which could reduce hospital emissions. However, after its use the Healthdot’s battery is empty and the device has to be disposed of. So this improvement in care comes at the cost of another disposable electronic device. While Philips already has made improvements to this with a circular successor, which contains reusable electronics, I believe that we can do this more sustainably. With this thesis, I aim to inspire designers, engineers and anyone else involved in the development of medical products to create more circular solutions, to reduce the impact we have on our world. 1.1 Medical wearable sensors The Healthdot can be categorised as a medical wearable sensor (MWS), but what defines a medical wearable sensor? This is a group of products that sense bio measurements from patients, such as heart rate or ECG signals, wirelessly. They are commonly attached to the patient using an adhesive patch and monitor the patient without the use of external devices for an extended amount of time. Some have data connectivity to allow continuous monitoring by hospital staff, and other record data to be read and analysed later. Wells et.al (2022) define a category of ‘wearable sensors’ as follows: “a device worn on the external body surface, unencumbered by wires, for the continuous and non-invasive detection of biosignals 17 (such as movement, heart rate, respiratory rate, and oxygen saturation).”. This definition is used by Wells to define the Healthdot but also includes products such as smartwatches, which he also compares in his paper. While this definition captures the sensing side of the Healthdot, it also allows non-medical products to enter the category. For this reason, the term ‘medical’ was added to this definition, creating the following working definition for this thesis:“A medical device worn on the external body surface, unencumbered by wires, for the continuous and non-invasive detection of biosignals (such as movement, heart rate, respiratory rate, and oxygen saturation).” 1.1.1 The current state of the medical wearable sensor market There are several MWS on the market, see Figure 1.2, however, most seem to operate in the US market. Little information was found on the adoption of these devices in the European healthcare sector. Most devices are single-use devices, but Vivalink and Philips’ BioTelemetry were two companies that I found that create reusable sensors. Interestingly enough, most of these ECG sensors appear to market themselves more towards a ‘medical consumer’, rather than directly on hospital use. This likely indicates that there is no medical reusable sensor on the market that is focused on reuse after hospital use. However, please not that this is a high-level scan, and further market research should be done to conclude on this. Vitalpatch - Vitalconnect Single-Use Device ECG (Vitalconnect, n.d.) Zio XT - iRhythm Single-Use Device ECG (iRhythm, n.d.) Figure 1.2: Medical Wearable Sensors from different manufacturers 18 Wearable ECG monitor - Vivalink Reusable Device ECG (Vivalink, n.d.) Healthdot - Philips Single-Use Device Vitals Philips, n.d.-d) ePatch - BioTelemetry Reusable Device ECG (BioTelemetry, n.d.) AT Patch - ATSens Single-Use Device ECG (ATsens, n.d. Centroid - Masimo Single-Use Device Vitals (Masimo, n.d.) 19 This chapter outlines the purpose and approach of this thesis. It begins by defining the thesis's objective, followed by an explanation of its structure. The research questions are presented, and a detailed description of the case study is provided. Lastly, the process of generating insights is illustrated. With my thesis, I aim to present insights for designers that can be used in the design process to improve the circularity of MWS. I will do this by first analysing an existing medical wearable sensor, the Philips Healthdot, after which a proposal for a circular redesign is made. The final insights are presented in the form of recommendations and can be found in Section 12.4. I aim to address the knowledge gap that exists when it comes to designing circular MWS. At the time of writing no previous work was found that specifically focuses on the design of circular and small medical electronics like the Healthdot. One master thesis was found that focused on the Healthdot, which focused on engaging patients in a circular Healthdot (van Hamersveld, 2019). The main deliverables of the thesis were recommendations for designers regarding the circular design of MWS and a concept that shows how a circular Healthdot and its system could look like. Some core activities include the analysis of the current Healthdot and the creation of a circular system. Out of scope were activities such as embodiment and patient interactions, as these were found to not add significant value to this thesis in particular or are already covered in the DiCE project elsewhere. In Appendix A the full scope can be seen. It is important to emphasize, that the concept presented in Chapter 9 is developed to create recommendations for designers, based on a case study where the Healthdot is used as a reference design. It serves as an inspiration and a vision of what a circular system could look like and does not offer a closing design. 2.1 Thesis Structure To bring structure to my thesis I used the Reflective Transformative Design Process (RTDP) (Hummels & Frens, 2009), with some elements from Integrated Creative Problem Solving (iCPS) (Buijs & van der Meer, 2013). RTDP differentiates between five phases, as seen in Figure 2.1, between which you move flexibly 2 • Aim and Approach Figure 2.1: RTDP and the process flow between phases using reflections. The method focuses on information and information flows, which suits the research through design approach of this thesis. iCPS has a clearer division between phases, which I found did not work for me in this project; the flexibility of RTDP had my preference. However, I did use the project management and overview steps from iCPS as an addition to the 20 “..present insights for designers that can be used in the design process to improve the circularity of MWS” The aim of this thesis is to RTDP method. For a more detailed comparison, see Appendix B. 2.2 Research Questions This thesis is guided by the following research question: What should designers keep in mind when designing circular MWS? With the following sub-questions to support the process: RQ1. What is the circular economy? RQ1.1 What defines the circular economy RQ1.2 How do you design for the circular economy RQ2. What is the current status of the Healthdot? RQ2.1 What is the environmental impact of the Healthdot? RQ2.2 Who are the stakeholders in the system? RQ2.3 What are the barriers and opportunities to a circular system? RQ3. What could a circular MWS look like? RQ3.1 What could a circular system look like? RQ3.2 What could a circular Healthdot look like? 2.3 Knowledge Acquisition To gather literature I performed an explorative search on databases such as Google Scholar, PubMed and ScienceDirect for a variety of keywords. Selected papers were scanned for their relevance and read if found relevant. Some unpublished or confidential background knowledge was used, however, all data presented in this thesis are acquired from public sources. Furthermore, I had (informal) conversations with people at Philips (n=3), Games for Health (n=3), the Erasmus MC (n=2) and the LUMC (n=1) to gain information not found in papers and to validate findings. Data was collected by taking notes and in some cases, audio recordings (n=3). 2.4 Research Through Design: a Case Study Approach To generate insights on how MWS can become circular, I selected a case study approach as my method. In this case study I went through the design process, from problem analysis to concept selection, and reflected upon my process to generate these insights. I have looked at different recovery flows, how they affect circularity and how to choose between these options. The Healthdot currently on the market is a single-use device, meaning that after its use it is disposed of. For reasons stated earlier, this needs to change. The new Healthdot 5.0 is already an improvement, featuring a reusable printed circuit board (PCB), but I think we can go further; I think that the Healthdot has great potential for reuse. Other medical electronics already have shown that it is possible to reuse complete devices (see Section 1.1), so why shouldn’t the Healthdot be reusable too? For these reasons, I believe that the Healthdot makes a good fit as the subject of this thesis. But how can it be made circular? Does it even make sense to make it circular? Is reuse even the best option? This leads to the following design challenge: “... to improve the circularity of the Philips Healthdot“ 2.4.1 Design process For the design process, I used the double diamond method as a guideline. The process had an iterative nature, when needed choices were made earlier, later or revisited. The four phases were used in conjunction with the RTDP described earlier. This process can be seen in Figure 2.2, with references to relevant sections. 2.5 Insight Generation To come to insights, I reflected on my project and discussed this with peers, as well as perspectives. In these reflective moments I focussed on the activities that I had done and what stood out to me, and especially focussed on why I did it. I focussed on finding tensions between activities, and I translated the results of these reflections into insights. I used perspectives to take on different mindsets of different readers, for example, a ‘business’ perspective or a ‘materials-engineer’ perspective, to try and find insights that I otherwise would have missed. Insights are presented in the form of take-aways at the end of their relevant chapters. An overview can be found in Appendix C. 22 Figure 2.2: General design process followed in this thesis Context analysis Discover Define Develop Deliver Conversations with experts Ideation Scenarios Product journey weighted critera R-strategies Brainstorm How-To’s What is possible? What does it do? Scamper Morphological Chart How will the system work? Where will it be reused? What will it look like? Final Design What is its impact? How big wil it be? What should the product do? How will it be reused? What does the sensor do? 23 Part two: the circular economy 3 • What is the Circular Economy 4 • Designing for the Circular Economy context analysis Part three 5 • The Philips Healthdot 6 • Stakeholders 7 • Barriers and Opportunities 8 • Design Requirements and Criteria In this chapter, the Healthdot is looked at in more detail. First, a detailed look at the product is given, after which its product journey is analysed. Finally, a fast-track life-cycle analysis is performed to assess its environmental impact. The Philips Healthdot is currently deployed by Philips and used in hospitals in the Netherlands. The sensor is currently on version 3.1 and is a medical device classified as a Class IIa product (European Commission, 2023). It measures heart rate, respiratory rate and patient activity, which is then uploaded to the hospital (Philips, n.d.-c), however, this also means that personal data is stored on the device. It is a single-use device and can be used for up to 14 days. Currently, Philips is developing a new, circular version called the Healthdot 5.0. This version features a larger battery which can be used for up to 30 days, but what is more significant, is that after its use the PCB can be removed and reused (personal communication, 14-032023). Within the context of DiCE, version 5.0 is the subject of research towards collection, reverse logistics and remanufacturing. However, due to confidentiality constraints, this thesis focuses on a redesign of the Healthdot 3.1; any reference to the ‘Healthdot’ in this thesis refers to this version (3.1) unless stated otherwise. The Healthdot consist of five major parts – a PCB, a battery, an upper and lower casing, and a skinadhesive patch – and some smaller components, which can be seen in Figure 5.1-5.3. It weighs 12 grams, has an IP55 rating and LoRa connectivity (Philips, n.d.-c). It is glued together, making recycling very difficult. It comes packaged in a blister, together with a simple instruction manual, and is shipped out in boxes containing 30 units. 5.1 Product Journey To gain insight into how the Healthdot is used and its system works, a product journey was created. In a conversation with Philips, four possible scenarios were described that the Healthdot might go through, see Figure 5.4. They can be categorised into preoperative use (scenarios 1 and 2) and post-operative use (scenarios A and B). While the Healthdot can be used for other treatments as well (Philips, n.d.-d), it was decided to focus on a surgery context due to the scope of this thesis. Scenario 2 describes a situation where the Healthdot is used for trending; collecting data before treatment to establish a baseline. Currently, scenario 1 is predominantly used, which is why scenario 2 was left out of scope. Scenarios 1A and 1B were further developed into a product journey, which can be seen in Figure 5.5. It is assumed the Healthdot is used 50% in scenario 1A and 50% in scenario 1B. In Appendix E a detailed product journey can be found. 5 • The Philips Healthdot Figure 5.1: The Philips Healthdot. (Philips, n.d.-d) 34 Figure 5.2: Dimension of the Healthdot, on a 1:1 scale. Figure 5.3: Exploded view of the Healthdot. Image courtesy of Philips (Personal communication, 08-08-2023) Table 5.1: Components and weights of the Philips Healthdot. Data courtesy of Philips (personal communication, 08-08-2023) Part ID Name Mass (grams) 1 Casing, Top ~ 2 2 Membrane filter <<1 3 Seal Tape (including the release liner) <<1 4 Batteries 2*1.68 = 3.36 5 PCB ~ 3 6 Casing, Bottom ~ 2 7 Skin Adhesive Assembly ~1 8 Circuit Breaker Tab <<1 9 Product Label <<1 10 Glue (0.04 mL) <<1 Total 12 55mm 45mm 33mm 11mm 40mm 35 pre-operative Scenario 1 Scenario 2 Scenario A Scenario B in-hospital post-operative Docter determines post-operative use of Healthdot Patient is operated Nurse places Healthdot Patient leaves hospital Patient applies pre-sent healthdot Patient stays in-hospital Patient removes and disposes the Healthdot Nurse removes and disposes the Healthdot Docter determines preand post-operative use of Healthdot Scenario 1 In this scenario the Healthdot is only used for post-operative monitoring. This means that before going to the hospital for surgery, the doctors determine that a Healthdot is used after surgery but the patient has no interaction with the product. After the surgery, the product is placed on the patient. Scenario 2 In this scenario the Healthdot is used for pre-operative trending and post-operative monitoring. The doctors determine that establishing a baseline or finding trends in heartand respiratory rates is necessary, and send the patient a Healthdot. The patient then has to place and activate the Healthdot themselves. In the hospital, the Healthdot is removed from the patient pre-surgery, and after surgery a new one is placed. Scenario A In this scenario, the patient is capable of going home immediately (<24h) after surgery. The Healthdot is placed on the patient, which allows the hospital to monitor the patient remotely. This scenario is very patient depended. Philips noted that some patients have to wear it for only 2-4 days, while other patients are required to wear it for up to 14 days. Scenario B In this scenario, the patient is required to stay in the hospital for monitoring. The Healthdot is applied here to allow the patient to move freely through the hospital, and not to be hindered by wires. Before leaving the hospital, the Healthdot is removed from the patient. Figure 5.4: Possible use scenarios for the Healthdot 36 Product Use Healthdot is stored until it’s needed Healthdot is scanned when placed to activate it Healthdot is placed on the patient Healthdots are manufactured and assembled at the factory Factory Internal use External use Philips Healthdot After 14 days, the Healthdot is removed Patient goes home with the applied Healthdot After 14 days, the Healthdot is removed The Healthdot is disposed of Figure 5.5: The Healthdot’s product journey 37 Reflection At first, I decided to focus solely on scenario 1A, as this is the most common-use scenario for the Healthdot. However, in a later conversation with Philips where concepts were discussed, it became apparent that changing the scenario you design for will subsequently change the circular system you design. In this case, adding scenario 1B to the scope changes where the Healthdot ends after its life, changing the options for your collection system. For this reason, both scenarios 1A and 1B were included in the final product journey. 5.2 Life Cycle Analysis Although the Healthdot is a relatively straightforward product, it is still valuable to analyse its environmental impacts. To get an overview of the impact of the different components, I performed a fast-track Life Cycle Analysis (LCA) using the 2023 Idemat database (Stichting Sustainability Impact Metrics, n.d.-a). This method is used to quickly get a rough evaluation of the eco-burdens of a product throughout its life cycle (Stichting Sustainability Impact Metrics, n.d.-b). However, it’s important to note that due to the nature of this fast-track LCA, several assumptions had to be made. As a result, no specific amounts for CO2 are mentioned, but approximations are offered instead. In this LCA, only the Healthdot’s primary parts mentioned previously are taken into account, the weight of which is given in Table 5.1. Not enough detail is known on the weights of the other parts, and it is assumed they’re too small to have a significant impact. The casing of the Healthdot is made from an ABS + PA blend, which due to lack of data is simplified to ABS. In this analysis one life cycle of the Healthdot is tracked, according to the product journey from Figure 5.3. It is assumed that it is produced at Philips in Eindhoven and transported to the Erasmus MC in Rotterdam. As previously described in Section 5.1, it is assumed that 50% of the use cases are outside the hospital. It is assumed the patient travels 5 km (CBS, 2023) from the hospital to their home by car. For its end-of-life, a worstcase scenario of incineration is assumed, in part due to a lack of data on the eco-impacts of the recycling of PCBs. Packaging was not taken into account as no detailed information was available. The results of the LCA can be seen in Figure 5.6, and a detailed calculation can be found in Appendix F. As expected, the PCB has by far the biggest impact on the sustainability impact of the Healthdot. Electronics are challenging to recycle, and with their high production impact – over 150 times that of ABS, according to the Idemat database – it makes sense to keep them cycling for as long as possible, which will be done with the new Healthdot 5.0. Because the Healthdot is so light and small, the transport movements barely show up on the graph. It is assumed that transport from the factory to the hospital will have more impact if the packaging is counted. 5.3 Take-Aways I6: It is important to choose the right scenario and context, as small changes here can drastically influence the outcome of your design. I7: LCA’s are a valuable tool to understand where the impact lies in your product, or why your product isn’t circular. If you could only save one component, which one would it be and why? For example, the PCB has the biggest impact on the Healthdot, so it makes sense to make this part last as long as possible. I8: LCA’s can be tricky, as minor changes in your assumptions can drastically change its outcomes. Test different assumptions in your LCA to see how these affect the impact of your product. 38 Figure 5.6: The Healthdot’s LCA results 0 300 600 900 120 0 1500 End of Life Transport Skin Adhesive Housing Battery PCB 0 5 10 15 20 End of Life Transport Skin Adhesive Housing gCO2 emissions gCO2 emissions Healthdot CO2 emissions 39 In this chapter, the two core stakeholders of this product - the Original Equipment Manufacturer (OEM) and the hospital - will be discussed, followed by an exploration of the possibilities for the hospital. The OEM – in this context Philips – is responsible for manufacturing the product. Philips is a company producing both healthcare and consumer products, primarily focusing on health-related items (Philips, n.d.-a). They need to ensure a high level of quality, take responsibility for the product’s safety and need to be a reliable partner. The hospital – in this case study the Erasmus MC in Rotterdam – uses the product. The Erasmus MC is a university medical centre specializing in delivering complex medical care, with over 30.000 patients being admitted each year (Erasmus MC Foundation, n.d.-a). They are accountable for providing quality healthcare and procuring the products that support this goal. While the Erasmus MC manages its own sterilisation department, smaller hospitals commonly rely on thirdparty service providers for this. These service providers take care of the collection, cleaning and sterilisation of used surgical equipment. Although the Erasmus MC serves as the example hospital in this thesis, concepts shown later in Chapter 10 will consider 3rd party services as well. Within the hospital, the doctor, nurse and patients are also stakeholders in this system. However, the requirements of doctors, nurses and patient are already part of the hospital’s requirements, as a result of their internal processes. As such they are viewed as secondary stakeholders to the hospital. 6.1 Possibilities of the Hospital During a conversation with the procurement department from the Erasmus MC (personal communication, 0205-2023), it became clear that logistics in a hospital are complex and demanding. An example was given that illustrated that hospitals are already quite taxed when it comes to cleaning: cleaning more clothing, such as gowns, would involve additional collection, separation, and washing processes, adding to the existing workload. Similarly, another idea to separate a type of plastic for recycling would require a second waste handler, as the current waste handler could not 6 • Stakeholders 40 manage this type of plastic. That means that instead of one you now have two people going through the hospitals to pick up waste, which further burdens the system. When discussing whether the hospital would be willing to be the product owner, an interesting perspective was raised regarding the manufacturer’s intent. If an OEM creates a reusable product but would still use a linear model (e.g., buy more sell more), it may not show genuine intent towards circularity from Philips, leading to concerns about trust and quality of the device. In a second conversation with a sustainability manager from the Erasmus MC (personal communications, 2706-2023), it was mentioned that the hospital already reuses some portable devices, notably the Holter monitors, which are wearable ECG devices which monitor the patient for up to 48 hours. After use, the devices are returned to the polyclinic where the data is downloaded and analysed. Cleaning of these kinds of devices is simple and can be done by anyone using alcohol wipes. The Healthdot could follow a similar cleaning schedule. Alternatively, the Central Sterilisation Service also disinfects products, such as endoscopes. However, not all hospitals have an internal sterilisation service. 6.2 Take-Aways I9: Circularity requires a broader mindset. It significantly changes the approach, scope and boundaries of your project, requiring a more holistic approach. I10: Integrate your stakeholders in the design process. Stakeholders hold valuable knowledge, they have ideas on what is and isn’t possible, both in the current systems and the system you are designing. Within a stakeholder, different departments will give you different perspectives, possibilities and information. I11: The stakeholders are going to execute your system, involving them in your process might make it easier for them to accept the solution. I12: The circular actions and intentions of an OEM hold meaning to the buyer. If an OEM remains the owner of the product, it demonstrates their active involvement in the product’s circularity, while if it is sold via a linear model you could question their intent. 41 design Part four 9 • Design of the Future Circular System: SecondSense 10 • Designing SenseFlow 11 • Designing SenseCab In this chapter, I present SecondSense, a potential solution to make MWS circular. First, the concept is introduced, and then its secondary parts are discussed in more detail. Finally, a comparison is made with the original Healthdot. SecondSense is a product-service-system, which allows easy and quick reuse of multiple MWS. It consists of two parts: SenseFlow and the SenseCab. SenseFlow describes how the sensors flow through the circular system, while the SenseCab enables easy reprocessing of the sensors. With SenseFlow, medical wearable sensors are returned to the hospital after use where they are cleaned and prepared for the next use. The manufacturer remains the owner of the sensor, being responsible for the quality of the sensors and for what happens at the sensor’s endof-life. The hospital cleans and controls the sensors, after which they are placed in the SenseCab. The SenseCab is a universal device that can update, charge and disinfect different sensors from different manufacturers, and makes them ready for reuse. When a sensor is needed, simply grab the sensor and the required patch, and you’re ready to sense! 9.1 Context: five years from now For the design of SecondSense it was decided to design for use in a future context, as remote monitoring – or telehealth – is expected to become more common in the future for a variety of treatments (Siwicki, 2023). More telehealth would lead to more sensors being used in and out of hospitals. For this reason, a future context five years ahead from now was chosen. In this context, it is assumed that there are multiple medical wearable sensors that are reusable. These sensors are used both internally and externally and need to be managed by the hospital. 9 • Design of the Future Circular System: SecondSense 50 Product Use Internal use External use Reprocessing Factory Reuse Phase SecondSense Use Phase Preparation Figure 9.1: An overview of the SecondSense sytem 51 Touch screen Frosted Glass Figure 9.2: Front view of a closed SenseCab: 52 Wireless Chargin Multiple sensors Figure 9.3: Angled view of an open SenseCab 53 9.2 SenseFlow The SecondSense system’s circular flow is called SenseFlow. It consists of two core phases: the use phase and the reprocessing phase. The use phase describes the use of the sensor, both internal and external of the hospital. The reprocessing phase focusses on cleaning and preparing the sensor for another use, as well as handling the rejected sensors. This flow is described in Figure 9.4, and further detailed in the following sections. The business model is based on the access and performance model from Bocken (2016). The OEM – here Philips – stays owner of the MWS, while the hospital pays per use. This gives the OEM control over the end-of-life of the sensor, reducing spillage, and incentivises the OEM to design long-lasting products; the more a sensor can be used, the more profit they make. The actions required by the stakeholders – The hospital and the OEM, Philips – can be summarized by the following list: • The hospital applies the Healthdot on the patient • The hospital removes internally used Healthdots from the patient • The patient sends their externally used Healthdots back to the Hospital • The hospital takes care of collecting the used Healthdots, inspecting them and cleaning them • Philips provides support, supplying new patches and – when needed – new Healthdots • Philips takes care of old and rejected Healthdots 9.2.1 Use phase The use phase of SenseFlow describes how the sensor is used, from application to collection. When a sensor is needed, a nurse takes the required sensor – in this case, a Healthdot – from the SenseCab, along with the required patches and other materials. The nurse then places the Healthdot on the patient and activates it, linking it to the patient. If the patient stays in the hospital, the Healthdot is removed by a nurse when it is no longer needed. The used patch is disposed of and the Healthdot is returned to the policlinic to be reprocessed. When the patient goes home with the Healthdot, the patient removes the Healthdot when it is no longer needed. After removing it, they separate the Healthdot from the patch – which is disposed of – and the Healthdot is sent back to the hospital. As you might notice, the use phase is still largely similar to the product journey described in Section 5.1. This is because no significant changes were made to the working of the sensor; the application and use stay the same. The difference is that some extra preparation is needed before use and the sensor has to be collected after use. 9.2.2 Reprocessing Phase The reprocessing phase of SenseFlow describes how the sensor is prepared for another use. When the Healthdot is returned to the policlinic, it is inspected for damages and cleaned with an alcohol wipe. The Healthdot is then scanned to check if it is still safe to use, and is placed in the SenseCab. In the SenseCab, the Healthdot is updated and personal data is removed, it is UV-disinfected and finally charged, all automatically. When it is time to use the Healthdot, it is scanned again to register its movement and prepared with a new patch. Healthdots that don’t make the safety check are collected separately and sent back to Philips. Here they are taken apart, the PCB is checked to see if it can last another life cycle and the casing of the sensor is recycled. Philips sends new Healthdots and patches to the hospital to be used again. 9.3 SenseCab The SenseCab is the enabler of the SenseFlow system; it allows easy reprocessing of the used sensors (Figure 9.5-9.11) The SenseCab is responsible for charging, removing and updating data, and disinfecting the sensors. The sensors are placed inside the cabinet on a wireless charging plate, where they are charged, personal data is removed and software is updated. The cabinet contains UV-LEDs which disinfect the sensors during their charge (Messina et al., 2015). The frosted glass front door protects the nurses from harmful UV light. When interacting with the SenseCab, the UV lights turn off and the glass door turns transparent for a quick overview of the sensors and their statuses. The touch screen on the front allows the staff to see the detailed status of the sensors inside without opening the cabinet, while the LED rings offer a quick status update. 54 Returned Healthdots are dismanteld The PCB’s are checked if they could go through another use cycle Failed Healthdots are replaced with new ones New patches and packaging is supplied Product Use Internal use External use Reprocessing Reuse Phase SenseFlow Use Phase Healthdot is stored until it’s needed Healthdot is scanned when placed to activate it Healthdots that don’t make the check are sent back to Philips Healthdot is placed on the patient The SenseCab checks if the sensor is still safe to use The Healthdot is scanned with the SenseCab, which douments their arrival After 14 days, the Healthdot is removed The Healthdot is seperated from its sticker The Healthdot is sorted for reuse The sticker is disposed of The Healthdot is sorted seperately and brought to the policlinic The Sensecab removes and updates data, disinfects, and charges the Healthdot, as well as any other MWS Healthdot is prepared with packaging and stickers per hospital protocol Preparation The Healthdot is ready for reuse! The Healthdot is seperated from its sticker Patient goes home with the applied Healthdot After 14 days, the Healthdot is removed The Healthdot is packaged and shipped back The sticker is disposed of Factory Figure 9.4: SecondSense's circular flow, SenseFlow, with description for its activities. 55 16 Sensors The SenseCab can handle 16 sensors at once, as demonstrated here by different dummy sensors Figure 9.5: Front view of an open SenseCab 56 Wireless Charging Puck Magnets hold the sensors against the wireless charging puck, which charges the sensor and connects it to the SenseCab. Figure 9.6: Close up view of the SenseCab's charging puck 57 gCO2 emissions 0 500 1000 1500 2000 2500 3000 3500 Healthdot SecondSense 1x 2x 3x 4x 5x 6x 7x 8x 9x 10x Patient - Hosptial Transport* Skin Adhesive* Cleaning Share in the casing Incineration Transport* Housing* Battery PCB * values are low, not visisble in graph CO2 impact comparison between the Healthdot and SecondSense Figure 9.12: CO2 impact comparison between the Healthdot and SecondSense 64 Figure 9.13: Night view of the SenseCab 65 In this chapter, the design process which led to SenseFlow is described. First, an overview is given of the process, after which the subsequent design steps are described in more detail. Finally, two final concepts are described, and arguments are given for the choice for SenseFlow. 10.1 Design Process The design process that was followed can be roughly described in Figure 10.1, which shows the different phases and includes references to their relevant sections. First, in the Ideation phase, the literature described in Chapter 4 was used as a starting point, which resulted in system possibilities (Section 10.2). These where then used to create concepts (Section 10.3), after which a choice was made for the final design, SenseFlow, described previously. 10 • Designing SenseFlow Ideation Chapter 10.2 Chapter 4 Chapter 10.3 Chapter 9.2 Concepting First Iteration Literature Results System Possibilities Second Iteration Factory Reprocessing Hosptial Reprocessing Final Iteration Final System Literature iterate + scamper criteria Circular Strategies Business Models Design Review LCA criteria Morphological chart WWWWWH A. Reuse B. Repair 1. Reuse or or first then then or 2. Repair 3. Remanufacture C. Remanufacture 9R Hierarchie Designing SenseCab Factory Returned Healthdots are dismanteld The PCB’s are checked if they could go through another use cycle Failed Healthdots are replaced with new ones Preparation External reuse flow 3rd Party Philips Packaging The Healthdot is packeged with new patches and packaging Interal use External use Healthdot is stored until it’s needed Healthdot is scanned when placed to activate it Healthdot is placed on the patient After XX days, the Healthdot is removed The Healthdot is seperated from its sticker The Healthdot is sorted for reuse and shipped The sticker is disposed of The Healthdot is seperated from its sticker Patient goes home with the applied Healthdot After 30 days, the Healthdot is removed The Healthdot is packaged and shipped back The sticker is disposed of The Healthdot is checked for their quality and safety The Healthdot is scanned so their arrival is documented The healthdot is cleaned (together with other sensors in a universal machine) The Healthdot is charged, updated and personal data is removed The Healthdot is ready for reuse! New patches and packaging is supplied Internal transport Reuse Phase Use Phase Product Use Returned Healthdots are dismanteld The PCB’s are checked if they could go through another use cycle Failed Healthdots are replaced with new ones New patches and packaging is supplied Product Use Internal use External use Preparation Reuse Phase Hospital reuse flow Use Phase Healthdot is stored until it’s needed Healthdot is scanned when placed to activate it Healthdots that don’t make the check are sent back to Philips Healthdot is placed on the patient The Healthdot is charged, updated and personal data is removed The Healthdot is checked for their quality and safety The Healthdot is scanned so their arrival is documented After XX days, the Healthdot is removed The Healthdot is seperated from its sticker The Healthdot is sorted for reuse The sticker is disposed of The Healthdot is sorted seperately and brought to the Central Disinfection Service The healthdot is cleaned and inspected together with other sensors in a universal machine? Healthdot is prepared with packaging and stickers per hospital protocol Packaging The Healthdot is ready for reuse! The Healthdot is seperated from its sticker Patient goes home with the applied Healthdot After 30 days, the Healthdot is removed The Healthdot is packaged and shipped back The sticker is disposed of Product Use Internal use External use Reprocessing Factory Reuse Phase SecondSense Use Phase Preparation Product Use Returning Product Reuse Produce Package Healthdot is stored until it’s needed Healthdots that don’t make the check are recycled New patches and packaging is supplied and put together with the Healthdot Failed Healthdots are replaced with new ones Healthdot is placed on the patient A clean and ready to go healthdot The Healthdot is checked for their quality and safety The Healthdot arrives at the factory Patient goes home with the applied Healthdot After 30 days, the Healthdot is removed The Healthdot is seperated from its sticker The sticker is disposed of The Healthdot is packaged and shipped back The healthdot is cleaned and inspected mechanically Healthdot is ready for use again Recycle Reuse Phase Use Phase Product Use Returning Product Reuse Reuse Phase Use Phase Produce Recycle Healthdot is stored until it’s needed Healthdots that don’t make the check are sent back to Philips New patches and packaging is supplied Failed Healthdots are replaced with new ones Healthdot is placed on the patient A clean and ready to go healthdot The Healthdot is checked for their quality and safety The Healthdot arrives at the Hospital Patient goes home with the applied Healthdot After 30 days, the Healthdot is removed The Healthdot is seperated from its sticker The sticker is disposed of The Healthdot is packaged and shipped back The healthdot is cleaned and inspected By hand Healthdot is prepared with packaging and stickers Preparation Figure 10.1: High-level overview of the process of designing SenseFlow 66 Ideation Chapter 10.2 Chapter 4 Chapter 10.3 Chapter 9.2 Concepting First Iteration Literature Results System Possibilities Second Iteration Factory Reprocessing Hosptial Reprocessing Final Iteration Final System Literature iterate + scamper criteria Circular Strategies Business Models Design Review LCA criteria Morphological chart WWWWWH A. Reuse B. Repair 1. Reuse or or first then then or 2. Repair 3. Remanufacture C. Remanufacture 9R Hierarchie Designing SenseCab Factory Returned Healthdots are dismanteld The PCB’s are checked if they could go through another use cycle Failed Healthdots are replaced with new ones Preparation External reuse flow 3rd Party Philips Packaging The Healthdot is packeged with new patches and packaging Interal use External use Healthdot is stored until it’s needed Healthdot is scanned when placed to activate it Healthdot is placed on the patient After XX days, the Healthdot is removed The Healthdot is seperated from its sticker The Healthdot is sorted for reuse and shipped The sticker is disposed of The Healthdot is seperated from its sticker Patient goes home with the applied Healthdot After 30 days, the Healthdot is removed The Healthdot is packaged and shipped back The sticker is disposed of The Healthdot is checked for their quality and safety The Healthdot is scanned so their arrival is documented The healthdot is cleaned (together with other sensors in a universal machine) The Healthdot is charged, updated and personal data is removed The Healthdot is ready for reuse! New patches and packaging is supplied Internal transport Reuse Phase Use Phase Product Use Returned Healthdots are dismanteld The PCB’s are checked if they could go through another use cycle Failed Healthdots are replaced with new ones New patches and packaging is supplied Product Use Internal use External use Preparation Reuse Phase Hospital reuse flow Use Phase Healthdot is stored until it’s needed Healthdot is scanned when placed to activate it Healthdots that don’t make the check are sent back to Philips Healthdot is placed on the patient The Healthdot is charged, updated and personal data is removed The Healthdot is checked for their quality and safety The Healthdot is scanned so their arrival is documented After XX days, the Healthdot is removed The Healthdot is seperated from its sticker The Healthdot is sorted for reuse The sticker is disposed of The Healthdot is sorted seperately and brought to the Central Disinfection Service The healthdot is cleaned and inspected together with other sensors in a universal machine? Healthdot is prepared with packaging and stickers per hospital protocol Packaging The Healthdot is ready for reuse! The Healthdot is seperated from its sticker Patient goes home with the applied Healthdot After 30 days, the Healthdot is removed The Healthdot is packaged and shipped back The sticker is disposed of Product Use Internal use External use Reprocessing Factory Reuse Phase SecondSense Use Phase Preparation Product Use Returning Product Reuse Produce Package Healthdot is stored until it’s needed Healthdots that don’t make the check are recycled New patches and packaging is supplied and put together with the Healthdot Failed Healthdots are replaced with new ones Healthdot is placed on the patient A clean and ready to go healthdot The Healthdot is checked for their quality and safety The Healthdot arrives at the factory Patient goes home with the applied Healthdot After 30 days, the Healthdot is removed The Healthdot is seperated from its sticker The sticker is disposed of The Healthdot is packaged and shipped back The healthdot is cleaned and inspected mechanically Healthdot is ready for use again Recycle Reuse Phase Use Phase Product Use Returning Product Reuse Reuse Phase Use Phase Produce Recycle Healthdot is stored until it’s needed Healthdots that don’t make the check are sent back to Philips New patches and packaging is supplied Failed Healthdots are replaced with new ones Healthdot is placed on the patient A clean and ready to go healthdot The Healthdot is checked for their quality and safety The Healthdot arrives at the Hospital Patient goes home with the applied Healthdot After 30 days, the Healthdot is removed The Healthdot is seperated from its sticker The sticker is disposed of The Healthdot is packaged and shipped back The healthdot is cleaned and inspected By hand Healthdot is prepared with packaging and stickers Preparation 67 10.2 Circular Strategies and Business Models The first step in the design process was choosing the circular strategy and business model, as these play a crucial role in the design of your system. The circular strategy outlines how your system will align with the circular economy, such as whether you will prioritise reuse or remanufacturing. On the other hand, the business model describes the roles and actions of stakeholders, including responsibilities, ownership, and cleaning processes. The choices made here will have a significant impact on the design of both your system and the accompanying sensor. To identify suitable circular strategies and business models, they were assessed on the requirements from Chapter 8, the results of which can be seen in Table 10.1 & 10.2. It was found that reuse, repair and remanufacture are three fitting circular strategies. Likewise, access and performance, classic long-life model, and encourage sufficiency are three suitable business models. Together, these could result in a circular sensor. The three circular strategies were together into one solution, based on the inertia principle: “Do not repair what is not broken, do not remanufacture something that can be repaired, do not recycle a product that can be remanufactured. Replace or treat only the smallest possible part in order to maintain the existing economic value of the technical system.”(Stahel, 2010). This led to ideation on questions such as: Who will be responsible? Who will clean the sensor? Who will own the sensor? To give Philips an incentive to design sustainable and long-lasting products, they should aim for a steady revenue from the concept in this business model. In a more linear economic model (e.g. buy more sell more), no matter how durable the Healthdot is, Philips would need to continuously sell more products to generate revenue. Considering that the access and performance model is the only one among the three options that provide a continuous revenue stream, it appears to be the best fit for this case. Table 10.1: 9R-Strategies assessed on their fit to the requirements from Chapter 8 Circular Strategies Description Less e-waste when compared to current concept Less CO2 when compared to current concept Fits Definition given in Chapter 3 Enables multiple uses of PCB's Refuse Descriptions given in Figure 3.2 Y Y Y - Rethink Y Y Y - Reduce Y Y Y N Reuse Y Y Y Y Repair Y Y Y Y Remanufacture Y Y Y Y Repurpose Y Y Y N Recycle M M M N Recover M N N N 68 Table 10.2: Business models assessed on their fit to the requirements from Chapter 8 Business Models Description Less e-waste when compared to current concept Less CO2 when compared to current concept Fits Definition given in Chapter 3 Enables multiple uses of PCB's Access and performance Providing the capability or services to satisfy user needs without needing to own physical products Y Y Y Y Classic long-life Business models focused on delivering long-product life, supported by design for durability and repair for instance Y Y Y Y Extending product value Exploiting the residual value of products - from manufacture to consumers, and then back to manufacturing – or collection of products between distinct business entities Y Y M M Encourage sufficiency Solutions that actively seek to reduce end-user consumption through principles such as durability, upgradability, service, warranties and reparability and a non-consumerist approach to marketing and sales Y Y Y Y Extending residual value Exploiting the residual value of resources: collection and sourcing of otherwise “wasted” materials or resources to turn these into new forms of value M M M N Industrial symbiosis A processorientated solution, concerned with using residual outputs from one process as feedstock for another process, which benefits from geographical proximity of businesses M M M N 69 10.3 Two Concept Designs The chosen strategies and business model were used to start the ideation process, which let to multiple concepts described in Appendix G. The two final concepts are described here: Hospital Reprocessing and Factory Reprocessing. Both concepts are focussed on the reuse of the Healthdot through reprocessing. They share the same use phase, which is largely similar to the one described in Section 5.2, aside from changes in preparation and the fact that the Healthdot is now collected after use, instead of disposed of. Additionally, both concepts share the same business model: a product-service-system. Philips is and will remain the owner of the Healthdots. Every time the hospital activates a Healthdot, Philips gest a notification and can bill the hospital for its use. The hospital does not pay for new Healthdots, as this is provided by the service element. Finally, the two concepts differ in their reprocessing phases. The hospital concept is focussed on internal reprocessing in the hospital, whereas the factory concept is focussed on external reprocessing. 10.3.1 Hospital Reprocessing This concept focuses on internal reprocessing, as can be seen in Figure 10.2. After use, the Healthdot is sorted internally where it is reprocessed, either at the Central Sterilisation Service or at the policlinic, depending on hospital preference. Rejected Healthdots are returned to the factory, which supplies the hospital with replacement Healthdots and new patches. Key Stakeholder Actions • The hospital collects Healthdots used in the hospital internally • The patient sends their used Healthdots to the hospital • The hospital takes care of collecting the used Healthdots, inspecting them and cleaning them • Philips provides support, new patches and – when needed – new Healthdots • Philips takes care of old and rejected Healthdots Returned Healthdots are dismanteld The PCB’s are checked if they could go through another use cycle Failed Healthdots are replaced with new ones New patches and packaging is supplied Product Use Internal use External use Reprocessing Reuse Phase Hospital Reprocessing Use Phase Healthdot is stored until it’s needed Healthdot is scanned when placed to activate it Healthdots that don’t make the check are sent back to Philips Healthdot is placed on the patient The Healthdot is charged, updated and personal data is removed The Healthdot is checked for their quality and safety The Healthdot is scanned so their arrival is documented After 14 days, the Healthdot is removed The Healthdot is seperated from its sticker The Healthdot is sorted for reuse The sticker is disposed of The Healthdot is sorted seperately and brought to the Central Sterlisation Service The healthdot is cleaned and inspected together with other sensors in a universal machine? Healthdot is prepared with packaging and stickers per hospital protocol Packaging The Healthdot is ready for reuse! The Healthdot is seperated from its sticker Patient goes home with the applied Healthdot After 14 days, the Healthdot is removed The Healthdot is packaged and shipped back The sticker is disposed of 70 Returned Healthdots are dismanteld The PCB’s are checked if they could go through another use cycle Failed Healthdots are replaced with new ones New patches and packaging is supplied Product Use Internal use External use Reprocessing Reuse Phase Hospital Reprocessing Use Phase Healthdot is stored until it’s needed Healthdot is scanned when placed to activate it Healthdots that don’t make the check are sent back to Philips Healthdot is placed on the patient The Healthdot is charged, updated and personal data is removed The Healthdot is checked for their quality and safety The Healthdot is scanned so their arrival is documented After 14 days, the Healthdot is removed The Healthdot is seperated from its sticker The Healthdot is sorted for reuse The sticker is disposed of The Healthdot is sorted seperately and brought to the Central Sterlisation Service The healthdot is cleaned and inspected together with other sensors in a universal machine? Healthdot is prepared with packaging and stickers per hospital protocol Packaging The Healthdot is ready for reuse! The Healthdot is seperated from its sticker Patient goes home with the applied Healthdot After 14 days, the Healthdot is removed The Healthdot is packaged and shipped back The sticker is disposed of Figure 10.2: Hospital reprocessing concept 71 10.3.2 Factory Reprocessing This concept focusses on external reprocessing, as can be seen in Figure 10.3. After use, the Healthdot is sent to either the OEM’s factory or a 3rd party service provider, where the Healthdot is reprocessed – this would depend on the location of the factory relative to the hospital. The 3rd party service provider would send rejected Healthdots back to the OEM factory, while the OEM factory would be the sole provider of new patches and replacement Healthdots. Key Stakeholder Actions • The hospital takes care of collecting the internally used Healthdots and sends them to either Philips or a 3rd party • The patient sends their used Healthdot directly to Philips or a 3rd party. • At the collection facility, the Healthdots are inspected, cleaned and prepared. • Philips provides support, new patches and – when needed – new Healthdots • Philips takes care of old and rejected Healthdots 10.3.3 Concept Reviews Both concepts were reviewed in two sessions, one with representatives from Philips (n=1) and Games for Health (n=3) and one with a representative from the Erasmus MC (n=1). The first topic that came up was the chosen scenario. For this thesis, a scenario where the Healthdot is sent back to the hospital was chosen, due to the scope. However, what if the Healthdot would be returned at a ‘trustworthy medical location’, such as a pharmacy or a general practitioner? This would change how the Healthdot would be returned, and in turn, also affect how it would be reprocessed. For example, the pharmacy could also do reprocessing, or will the pharmacy sort the devices per hospital? A change in scenario can have a large impact on your design. A second topic that was discussed is the interchangeability of the different parts of the concepts. You can split each concept into two flows and combine these, see Figure 10.4. For this thesis, the choice is made for just one system. However, in practice it might be desirable for hospitals to be given a choice on how to reuse these products. Smaller hospitals might prefer external reprocessing because they lack infrastructure, while larger hospitals might have no issues with that and can handle a shorter loop. Finally, the topic of universality came up. All parties agreed that in a system like this, MWS should be compatible with the same system to make it feasible. If a hospital has to reprocess multiple different sensors and they would all have a unique cable, machine and reprocessing steps, this would become an impossible task. This is why it is important to use or develop a standard which is shared amongst different sensors. A real-world example is the standardized phone charger. Most readers of this thesis will remember the chaos of the first phones all using different charging cables. Nowadays almost all of them use the same charger, making it easy to recharge a variety of different phones. In the conversation with the Erasmus MC, some concerns came up. Most notably the question of ‘how do you make sure that you have enough Healthdots?”. If you run out of Healthdots, do you get sent more sensors? Or are you able to track were they are in use? This is important for the hospital to know because procedures are planned based on the available material, and is something that the system should accommodate. However, for this thesis, it was determined out of scope to integrate this into the current concept. 72 Factory Returned Healthdots are dismanteld The PCB’s are checked if they could go through another use cycle Failed Healthdots are replaced with new ones Reprocessing Factory Reprocessing 3rd Party Philips Packaging The Healthdot is packaged with new patches and packaging Interal use External use Healthdot is stored until it’s needed Healthdot is scanned when placed to activate it Healthdot is placed on the patient After 14 days, the Healthdot is removed The Healthdot is seperated from its sticker The Healthdot is sorted for reuse and shipped The sticker is disposed of The Healthdot is seperated from its sticker Patient goes home with the applied Healthdot After 14 days, the Healthdot is removed The Healthdot is packaged and shipped back The sticker is disposed of The Healthdot is checked for their quality and safety The Healthdot is scanned so their arrival is documented The healthdot is cleaned (together with other sensors in a universal machine) The Healthdot is charged, updated and personal data is removed The Healthdot is ready for reuse! New patches and packaging is supplied Internal transport Reuse Phase Use Phase Product Use Figure 10.3: Factory reprocessing concept 73 11.2 Design Challenges To create an enabler for the SenseFlow system, it is important to know what inhibits or blocks the circularity of the system. To achieve this, I identified challenges in the system by taking on the perspective of different stakeholders, users and topics. The results from this brainstorm were then organised into clusters on the SenseFlow map, which resulted in multiple design challenges, which can be found in Figure 11.2. A list of challenges and additional maps per perspective Appendix H. It is important to note that this overview is not exhaustive, and other designers may identify different challenges from the same perspectives. While many of these challenges are important to the success of this system, I can only focus on three due to the scope of this thesis. To determine these challenges, I first filtered them on their relevance to the scope and then selected the most critical ones. Criticality, in this context, refers to the challenges' importance to the success of the system and the extent of the knowledge gap they present. For instance, challenge 6 How do you know where your devices are' addresses the need for device control and prevention of device loss. However, since similar systems are already in use within hospitals, this may not represent a significant knowledge gap. The results of this process can be found in Appendix H. The chosen challenges are translated into the following design challenges: 11.2.1 Design Challenge 1 Design a solution where multiple MWS from different brands can be cleaned and prepared efficiently. This design challenge is based on challenges 16 and 17 and focuses on the preparation of the Healthdot. Preparation involves tasks such as charging, modifying data, and making it ready for another use. Sub challenges • How do you clean the device? • How do you charge the device? • How do you communicate with the device? 11.2.2 Design Challenge 2 Design a solution where multiple MWS from different brands can be quickly checked for their quality and functioning This design challenge is based on challenge 14 and focuses on controlling the quality and safety of the Healthdot. The Healthdot should be inspected to ensure that it is still safe and functional for reuse. Sub challenges • How do you make sure it is not damaged? • How do you make sure it still has uses left? • How do you make sure it is still functioning properly? 2. How do you minimize downtime in storage? 3. How does the patient know the device is safe? 7. How does the device communicate that it is functioning normally? 1. How do you guarantee supply of devices and supplements 5. What does the patient need when they take the device home? 4. How do you know how to apply the sensor? 6. How do you know where your devices are? 8. How do you reduce the impact of the used disposables? 8. How do you reduce the impact of the used disposables? 9. How do you make sure the patient returns the used device? 12. How can you optimize the reprocessing? 16. How to optimise the cleaning process for multiple devices? 10. How do you ship the used device back? 14. How do you know if the used device is still safe for use? 11. How do you sort the used device in the hospital? 23. How can you instil trust in remanufactured components? 17. How do you reuse the cleaned device? 18 How do you prepare the cleaned device? 13. How do you know what to do with the device? 15. How to collect the rejected devices? 19. How do you make sure you get rejected devices back? 22. How can you produce your device with the leaste amount of impact? 20. How do you disassemble/ remanufacture rejected devices? 21. What do you with components that can't be remanufactured? 80 2. How do you minimize downtime in storage? 3. How does the patient know the device is safe? 7. How does the device communicate that it is functioning normally? 1. How do you guarantee supply of devices and supplements 5. What does the patient need when they take the device home? 4. How do you know how to apply the sensor? 6. How do you know where your devices are? 8. How do you reduce the impact of the used disposables? 8. How do you reduce the impact of the used disposables? 9. How do you make sure the patient returns the used device? 12. How can you optimize the reprocessing? 16. How to optimise the cleaning process for multiple devices? 10. How do you ship the used device back? 14. How do you know if the used device is still safe for use? 11. How do you sort the used device in the hospital? 23. How can you instil trust in remanufactured components? 17. How do you reuse the cleaned device? 18 How do you prepare the cleaned device? 13. How do you know what to do with the device? 15. How to collect the rejected devices? 19. How do you make sure you get rejected devices back? 22. How can you produce your device with the leaste amount of impact? 20. How do you disassemble/ remanufacture rejected devices? 21. What do you with components that can't be remanufactured? Figure 11.2: Overview of design challenges 81 11.3 Concept Designs Next, a brainstorm session was done on the subchallenges, the results of which can be found in Appendix I. This resulted in the following four concepts: The Auto Pro, the Smart Scan + Wall Charge, the SenseCab and Standardised Batteries. The four concepts can be seen in Figure 11.3 and are described in the following paragraphs, with a more detailed description and image available in Appendix J. AutoPro is an automatic reprocessing machine. Sensors are placed on top, after which the machine disinfects and charges the sensor. Sensors that are ready for use can be found in a collection box, while rejected sensors are ejected in a separate container. Smart Scan + Wall Charge is a combination of two products. A basic wireless charging wall offers a starting point, by charging the devices, while a nurse cleans and updates the devices. A second device, the Smart Scan, can be purchased later and takes care of updating the device and doing a visual inspection. AI will be able to determine whether or not a sensor is still safe, leading to many more uses than the prescribed 10. SenseCab is an all-in-one solution. The sensor is placed inside, where it is automatically disinfected, updated and charged. A screen shows the information on the status of the sensors, and the UV lights are turned off when the cabinet is opened. Standardised Batteries use shared batteries between MWS. This allows MWS to quickly return to use. After a quick disinfection, replace the empty battery with a fully charged battery. The empty battery is cleaned and placed in a charging wall. The nurse has to manually scan the MWS to manage its data. 11.4 Concept Comparison To choose between these four concepts, I have compared them to the criteria outlined in Chapter 8 using the datum method (Boeijen et al., 2013, p. 147). In this method, one of the concepts is used as a reference (datum) against which the other concepts are compared. This was done twice, using Standardised Batteries and SenseCab as the datum, both weighted and unweighted. One datum is shown in Table 11.1, as all four datums gave the same outcome. These can be found in Appendix K. Based on the results of the datums and supporting arguments, I have selected SenseCab as the final concept. It outperforms the other concepts by a small margin, and in addition to that, I believe it is a concept that is both realistic and imaginable, while also inspiring a future perspective. 11.5 Final Iteration Finally, a last iteration was done to the design on the SenseCab. I have analysed the concept to identify the major challenges, the process and results of which can be found in Appendix L. This resulted in the final design, shown in Figure 11.4 and presented in Chapter 9. These challenges can be summarised as follows: 1. Charging: How will the device charge and stay attached to the cabinet? 2. Interaction: How do you know the status of the device? 3. Interface: What information does the interface share with the user? 4. Design: What will the aesthetics of the cabinet look like? 82 Figure 11.3: Four concepts for the design challenges 83 Device Criteria Standardised Batteries SenseCab Smart Scan + Wall Charge AutoPro 1 The solution should create as little CO2 impact as possible 3 2 1 1 2The solution should create as little e-waste as possible 3 2 2 2 3The solution should work as an example for other MWS 3 5 4 4 4The device should be as easily reusable as possible 3 4 4 5 5Machines that the hospital has to purchase should be as cheap as possible 3 2 1 1 6The solution should be as maintainence free as possible 3 3 3 1 7 The solution should be as simple as possible 3 4 4 5 8 The device should minimize cycle times 3 2 2 1 9 The device has to be checked for its quality as quickly as possible 3 3 4 4 10 The solution should instil the maximum amount of trust in the hospital staff 3 4 5 4 11 The solution should take up as little space as possible 3 3 3 3 12 The solution should be as time efficient as possible 3 4 3 5 13 The solution should have a minimal chance of failing 3 4 2 1 14 The solution should resist tampering from the patient 3 4 4 4 15 The solution gives the maximum form-freedom to the OeM's design team 3 5 4 3 Table 11.1: One datum method to compare the four concepts 84 11.6 Take-Aways I24: The device is an enabler for the system. Identify the challenges that the system has and determine which ones your device should solve. I25: The design process for the device doesn’t differ much from a regular design process. It is based on the requirements that result from the system designed previously. I26: The design of the system determines circularity at a high level: How will your product stay in the loop and get used as much as possible? The design of the product determines the circularity at a lower level: How much impact is created when using the product, and how easily can it be reprocessed or remanufactured? Figure 11.4: SenseCab's final concept design 85 recommendations Part five 12 • Conclusion and Recommendations 13 • Limitations and Further Research 14 • Personal Reflection This chapter concludes the thesis. First, the design goal and methodology are described, after which the research questions from Chapter 2 are answered. Recommendations are given for designers working with Medical Wearable Sensors (MWS), and finally, the implications of this thesis are described. 12.1 Design Goal The Healthcare sector has a large environmental footprint; 7% of Dutch national CO2 emissions are created by healthcare (Gupta Strategists, 2019), with an average of 2,4kg of waste per patient per day (Singh et al., 2022). With the introduction of the Healthdot, a medical wearable sensor, Philips aims to improve healthcare by allowing transitional care, which frees up bed space and can reduce hospital emissions. Medical wearable sensors (MWS) are a group of medical devices that wirelessly sense bio measurements, such as heart rate or ECG signals. While these devices can improve healthcare by allowing transitional care, many are single-use devices that are disposed of after use, adding to the already large amount of hospital waste. They are especially harmful because they contain electronics, which are toxic to both humans and the environment (Lin et al., 2022; Ogunseitan, 2022; Wirtu & Tucho, 2022). The circular economy is one way to reduce the CO2 emissions and e-waste generated by these products. However, no previous research was found that specifically addresses the circular design of MWS. To address this knowledge gap, this thesis aims to present insights for designers to be used in the design process to improve the circularity of MWS. This process is guided by the research question “What should designers keep in mind when designing circular MWS?”, and is supported by the following: 1. RQ1: What is the circular economy? 2. RQ2: What is the current status of the Healthdot? 3. RQ3: What could a circular MWS look like 12.2 Methodology To answer these questions, a case study was executed, focussing on the redesign of a MWS. In this case study, the design challenge is formulated as follows: “to improve the circularity of the Philips Healthdot”. Initially, an exploration of existing literature was performed to gain an understanding of the circular economy and to find existing solutions for design strategies and business models. Subsequently, an analysis of the Healthdot and its context was conducted to identify barriers and opportunities, which resulted in design requirements for a circular redesign. Furthermore, a Life-Cycle Analysis (LCA) analysed the Healthdot’s eco-impact. These results were used as a basis for the development of SecondSense, a proposed circular MWS system consisting of two parts: SenseFlow and SenseCab. Through a comparative LCA, SecondSense’s environmental impacts were compared with the Healthdot, showing major reductions in CO2 emissions. Conclusively, the insights generated during the design process were used to create recommendations for designers. 12 • Conclusion and Recommendations 88 12.3 Findings This section answers the three research questions described in Chapter 2. RQ1: What is the circular economy The circular economy refers to a system that is restorative by intention (Ellen MacArthur Foundation, 2013a), and unlike the linear ‘take-make-waste’ model, ensures that resources are kept in use as long as possible. A common framework to visualise the principles of the circular economy is the Adapted Value Hill (Figure 12.1). It illustrates the rule of thumb that the shorter you keep the circular loop, the more value you maintain and the more circular you become. The framework combines the Value Hill (Achterberg et al., 2016), with the 9R model (Potting et al., 2017). However, it is important to note that this is a simplified version of the circular economy. These frameworks are explained in more detail in Chapter 3. There are many definitions for the circular economy; in one instance, 114 different definitions were found in different papers (Kirchherr et al., 2017). For this thesis, an adaption of Geisendorf & Pietrulla’s (2018) definition is used: “the value of products and materials is maintained, Figure 12.1: Adapted Value Hill (Metabolic Institute, 2021) 89 Figure 12.4: Front view of the SenseCab during a disinfection cycle 96 12.4 Recommendations for Designing Circular MWS Based on the outcomes of the case study, recommendations are formulated that address the knowledge gap that exists when it comes to designing circular MWS, described above. They offer a starting point for designers and engineers to create circular solutions for MWS. 12.4.1 Circular design vs. classic design FFirst, a brief comparison is given to highlight the differences between a ‘circular design process’ and a ‘classic design process’. While circular systems can be complex, their circular design process is in essence similar to a ‘classic’ product design process. Initially, a context is determined, subsequently, product requirements are set up and finally, a concept is developed. However, in a circular design process, there is a consideration not only of the product’s use phase but also of how the product – in whole or in part – can be retained within the circular loop. A circular design process demands extended effort, as it involves designing a system that retains the device, in addition to designing the device itself. It adds complexity to the process. Circular systems are complex because they describe more than a linear system, as is illustrated by the difference between Figure 12.2 and 12.4. However, designing for the circular economy doesn’t have to be complex, as a structured approach is maintained. The following sections describe two sets of recommendations for designing circular MWS, with applicability extending to the design of other circular products. 12.4.2 Understand the principles of the circular economy and how to design for it To effectively design for the circular economy, comprehending its core principles is a must. Thus, the first set of recommendations centres on creating an understanding of the circular economy. R1: Gain a solid understanding of the basic principles of the circular economy Multiple frameworks exist that describe the principles of the circular economy. A good starting point is the Adapted Value Hill, described above in Section 12.3.1, as it is intuitive yet comprehensive. However, it is also simplified and should be considered a rule of thumb. Chapter 3 of this thesis describes the principles of the circular economy in more detail. R2: Research circular design strategies and business models for the design challenge There is an extensive amount of research, which describes effective combinations of design strategies and business within the circular economy. The second recommendation is therefore to research and choose circular design strategies, relevant to your design challenge. In Chapter 4 circular design strategies and business models are described in more detail, and in Section 10.2, a potential approach for choosing between strategies and business models is described. R3: Determine what defines circular economy As discussed in Section 3.1, there are varied interpretations of how the circular economy is defined, which is why it is recommended to determine what definition for the circular economy is used. Firstly, a definition aids decision-making by aligning perspectives on what is circular; secondly, it can be used to create requirements and criteria, both at a system and concept level. 97 12.4.3 Structure your design process The second set of recommendations centres on structuring the circular design process. To design a circular MWS, the design involves both a system and a product. The system consists of a circular strategy, outlining how the product will remain in the circular loop, and a business model, describing how an OEM can generate profit. The product, in this context a sensor, functions as an enabler, designed to facilitate actions prescribed by the system to ensure its integration within the circular loop. R4: First, determine how the system is going to be circular, then design the product so that it enables this system. The circularity of the product is primarily determined by the system, which shapes the requirements for the product. For this reason, it is recommended to first determine how the product will become circular, by determining the strategy of the system. This results in design requirements and criteria, describing what the product should facilitate. As mentioned earlier, a structured approach is necessary when designing circular MWS. In this section, a structured approach based on the outcome of this thesis is suggested. R4.1 Take additional care when determining the boundaries. Begin by establishing the project’s context and boundaries. Describe aspects such as product use, user, stakeholder and potential reprocessing entities. Scoping and boundaries are important in any design project; however, this study revealed that even slight adjustments to these boundaries could yield in a completely different system, as detailed in Section 5.1. This subsequently affects the product as well. R4.2 Determine a detailed system outline Next, determine the circular strategy and business model. A recommended starting point is the literature mentioned in Chapter 4. These factors collectively shape the functioning of the system, which in turn dictates the requirements and criteria for the product. For instance, if the chosen circular strategy focuses on reprocessing, the device needs to be able to withstand cleaning, whereas a remanufactured-oriented approach would demand easy disassembly. Because the system lays the groundwork for defining product requirements, it is a must to craft a comprehensive summary of supporting activities. I recommend developing a high-level overview of the system at a minimum, similar to Figure 12.3. This outline should describe the necessary actions needed to maintain the product within the system. In this context, involved stakeholders should be determined and their associated tasks. R4.3 Analyse the system to formulate requirements With the system defined, analyse it to formulate requirements and criteria. The product’s central role within the system involves enabling the actions required by stakeholders to sustain circularity. If modifying an existing product, minor adjustments might suffice to align it with these requirements. R4.4 Integrate the classic design process into the circular system At this point, product requirements have been determined which leads to a circular product. The process shifts towards a more conventional design process. It is recommended to use a method familiar to you for the generation of ideas, concepts and final design. However, remain mindful of the circularity objectives defined earlier. 98 12.4.4 Final notes Throughout the design process, two activities stand out that can boost circularity. R5: Use fast-track LCAs for conceptual insights The first activity revolves around using Fast-Track LCA’s to quickly evaluate concepts, gaining insights on environmental impact within the designs. This helps determine what parts of the current product are most worthwhile to save, where improvements lie as well as compare ideas and concepts for their circularity. R6: Involve stakeholders in the design project The second activity focuses on involving stakeholders in the project. Stakeholders hold valuable knowledge for any design project. In a circular system, they are especially relevant, given their familiarity with the system. Moreover, they become central actors in the circular system; for instance, they might collect and reprocess your product. Involving them in the design process can increase the likelihood of these stakeholders adapting the solution. 12.5 Implications Finally, the implication of this thesis on the design of circular MWS, the environment and academia are described, concluding this thesis. 12.5.1 The potential of circular MWS Firstly, this thesis has demonstrated that a simple yet effective solution can be used to reuse MWS with minimal changes to its design. A universal solution that could be used across platforms is proposed, enabling easy reprocessing of a variety of sensors within a high-performance environment like hospitals. It offers valuable insights and recommendations for the design process, serving as an inspiration for future designers. Moreover, it introduces companies like Philips to innovative possibilities, that extend beyond their current circularity efforts, and suggests that cooperation between OEMs is important in a circular economy. 12.5.2 Environment Secondly, the SecondSense concept illustrates that a circular system in which MWS are reused can yield a substantial CO2 reduction. The thesis highlights possible improvements that could further decrease these emissions. Additionally, it underlines the benefits of localised reuse, encouraging OEMS to explore new solutions aimed specifically at reusing devices within a hospital setting. 12.5.3 Academia Lastly, the thesis underlines how academic research focused on circular design strategies and business models contributes to and can be utilised in a practical application of circular design. This is achieved by using academic research as a starting point for the development of a circular system. Furthermore, this thesis adds to this research by providing recommendations for designers, which can be used as a starting point for future circular design processes, not just for the design of MWS. In conclusion, the implications of this thesis could extend beyond the design SecondSense and have been demonstrated to add value to the design of medical wearable sensors, the environment and academia. 99 Due to the nature of this thesis, assumptions and limitations naturally come into play. In this chapter, the limitations of this thesis are discussed, and recommendations for further research are given. First, the limitations to the scope and boundaries of this thesis are examined, followed by the validation process with stakeholders and the LCA results. Lastly, constraints related to the recommendations are addressed. 13.1 Scope and Boundaries Given the constrained timeframe of this thesis, it was not possible to cover all aspects of the. This led to scoping, where the following elements were considered out of scope, for the following reasons. 13.1.1 Medical Regulations Firstly, medical regulations and laws were not taken into account. These regulations dictate the rules and standards to which medical devices should adhere. For instance, a reusable device has to be certified for a certain amount of reuse, and may not be reused beyond this limit. While the assumption that SecondSense aligns with regulations seems reasonable, as reusable MWS were found, it is not verified. It is plausible that major changes to the design need to happen, potentially impacting the circularity of the device or even preventing the device from becoming circular. Further research into the regulations that apply to MWS, and SecondSense in specific, is recommended. 13.1.2 Return Location Secondly, an early decision regarding the return method of the Healthdot was necessary in this thesis. Based on prior work and the DiCE context, it was presumed that the Healthdot is returned via postal service. As discussed in Section 10.3, a different return location will likely yield a different system. Further research is recommended to validate the current return method as well as to explore alternative options, such as pharmacy or general practitioner-based returns. This area is scheduled for research within DiCE and was thus excluded from this thesis's scope. 13.1.3 Economical Viability Thirdly, the economic viability of the concept is not analysed in this thesis. While a back-of-the-envelope estimation suggests viability, due to the sensor being able to be sold multiple times despite higher costs, no conclusions are drawn. Further research is recommended to assess the concept’s economic viability. 13 • Limitations and Further Research 100 13.2 Validation with Stakeholders While the concept is an improvement in environmental impact, it is not validated by stakeholders. Although concepts for SenseFlow were discussed and validated in conversations with stakeholders, the SenseCab design is based solely on the results of these conversations. The SenseCab, the final iteration of SenseFlow, and their combination are not validated by stakeholders or users. Subsequent research is recommended to evaluate the device with the stakeholders mentioned in this thesis. 13.3 Life Cycle Analysis Results Fast-track LCAs were used to compare concepts and validate findings. However, as noted in the report, results of fast-track LCAs are indicative, as they rely on assumptions and databases that may might not accurately reflect the actual situation. Still, these LCAs are presumed to offer a reasonable indication, and it is believed that a detailed LCA will yield similar results. Detailed LCAs were beyond the scope of the thesis due to time constraints. Further research is recommended to better understand the environmental impacts of the Healthdot and the SecondSense system. 13.4 Recommendations Finally, limitations also apply to the recommendations presented earlier. These recommendations are based on my personal experiences. While efforts were undertaken to ensure objective recommendations, inherent biases are difficult to eliminate entirely. This thesis marks my first venture into a circular design project of this scale, meaning it was a learning project. Consequently, the recommendations partially reflect my personal perspective and learning process. Peer students provided feedback on these recommendations, however, they were not validated. Further research is advised for the validation of these recommendations, such as co-creation sessions involving designers and engineers. 101 In this final chapter, I will reflect on my personal process: what did I learn, what would I do again and what would I do differently? First of all, thank you so much for reading my thesis. These 100 pages and eighteen thousand words are the result of half a year of hard work, sweat and tears – no blood, luckily. I hope you found it inspiring, and that it motivates you to design circular and sustainable solutions. A question most people ask a master's student after their graduation, is either ‘Would you do it again?’ or ‘Would you want to continue with your project?’. I would have to answer yes to both. I thoroughly enjoyed learning more about the circular economy, developing this system and especially seeing that it contributes to a better world. I feel that I can look back with pride on both my learning process, as well as my result. In this thesis, I learned that circular design is complex and requires a different, additional process. However, as long as you have a clear goal, it doesn’t have to be difficult. I found the project challenging, as I’ve never worked with sustainability at this scale and I’ve never designed a system, let alone of this complexity. If I would do the thesis again, I would repeat the design process. I believe it was the right process to start with, by determining and designing the system and following that up with requirements and the product. While it was a struggle at times to balance design strategies and business models, which I expect to become better with more experience. The biggest change that I would make to this thesis next time, concerns the structure. I think the design goal with which I started this project was a little undefined for me, and if I’d do the project again I would further define the project goal, creating a more concrete design goal. I always felt structure is essential for me, however, I also believe that because I had this open project, I could create the result I have now. Maybe it is time to rethink this. What I would do differently in my design process, is to involve stakeholders more and do LCAs earlier in the design process. It was difficult to connect to hospitals. Partially, because it was difficult to get in touch with the right person, but also because I think I was too busy trying to understand the system before talking to stakeholders and experts. However, talking with experts would have likely helped me understand the system as well. Once talking to them, I got useful information and insights. For me, this is a lesson to be more in touch with stakeholders and bring their expertise into play earlier, instead of trying to do it all by myself. In my process, I would use more LCAs. I think if I could have used LCAs at more points in the process, and would have gotten more valuable insights out of them. However, now that I have experience with LCAs, I expect to use them more in my decisions in the future. With this reflection, I close my thesis. This marks the moment where I go from being a student in design to an active practitioner, to make it as circular as possible. However, I want to never stop learning. Again, thank you so much for reading. If you want to learn more about this topic, feel free to shoot me a message. Kind regards, Matthijs 14 • Personal Reflection 102 103 references MAIN CHALLENGES CORE INTERESTING OUT OF BOUNDS Analysis of circularity options Creation of insights How is the cleaning process going to work in detail Defining circularity (for this project) Design of cleaning machine(s) Cleaning technologies Product Journey Who can/has to do what General cleaning processes Cleaning process journey Concepting for the redesigned healthdot Detailing of embodiment for production Embodiment for the redesigned healthdot Detailed development of logistical solutions Existing solutions for logistical problems Current Equipment cleaning processes Laws regarding cleaning concept creation for logistical solutions Existing business models Creating new business opportunities A sustainable prodcut also included buying and using only the itemas that you really need. However, that behaviour is unrelated to the design of the Healthdot, as its a medical descision not a comfort/luxury one Purchasing of device Nudging the patient to return the product Collection of MWS Analysing the current Healthdot Afval inzameling in ziekenhuizen? MWS used in the Netherlands Stakeholder analysis Analysis of current hospital systems Casestudy of Medical Wearable Sensors Analysing current MWS A • Scope To structure the project, I will use the Reflective Transformative Design Process (RTDP) with elements from the integrated Creative Problem Solving model (iCPS). Both methods feel very similar to me and have elements I like; what I like about RTDP is that it provides structure between activities by asking me to reflect in between activities to determine the next, and what I like about iCPS is that it implies project management and requires a greater overall view of the project. In the images below both models can be seen (RTDP on the left, iCPS on the right). B.1 Integrated Creative Problem Solving Integrated Creative Problem Solving is “a structured, iterative model that helps with developing novels and useful solutions to open problems in groups” (Delft Design Guide, 2020). It consists of four activities: Content finding, information finding, acceptance finding and project management. Content finding is subdivided into three processes: Problem finding, idea finding and solution finding. The project management process runs continuously and manages when the other three processes are done. These are managed simultaneously and executed without a prescribed order. It is up to me to determine which process is done and when. What I like about this project is that there is a focus on project management to determine which process needs to be done and when. What I dislike is that it does not contain a (dedicated) validation process and that the three phases feel separated from each other. The Delft Design Guide calls this separation essential. B.2 Reflective Transformative Design Process This method is new to me and comes from the design faculty in Eindhoven that “gives students grip on the design process yet leaves room for innovation” (Hummels & Frens, 2009). In this method, the designer has five activities to choose from, without a specific order. These activities are ideating, envisioning, validating, analysing and doing. The activities are split between Drive (vertical axis), which focuses on information gathering, and Strategies (horizontal axis), which focuses on information generation. It would be up to me to determine which method is best at that moment. Essential to the model is the reflection that takes place when switching between activities. What I like about this model is that it is focused on information and its flow, seeing how both axes are centred on information collection. I like this perspective on information. It feels very focussed on exploring and gaining new knowledge, but because you create this vision as well it gives you some handles to keep it relevant. What I dislike is that it feels like it misses a managing element or a moment where you step back and look at the bigger picture. B.3 Comparison I have analysed both methods to see how they compare to one another, and I have attempted to combine both methods into one visual. In comparing the two methods and while making this visual I learned more about both methods and how they are similar and different. RTDP is focused on the flow of information, how you gather it and how you generate it. This information is then spread across the different activities by doing, envisioning, analysing, validating or ideating. iCPS is focused on creating a structure to work efficiently with a team. It dedicates three different roles (facilitator, problem owner and resource group), whereas RTDP does not focus on a group or an individual. iCPS B • Reflective Transformative Design Process focuses on project management first and foremost, and from that managing perspective you look at what the next activity is going to be. I looked at what activities/processes and how they fit into one another. I found that acceptance finding (iCPS) can’t easily be placed in the RTDP model. Information is a major part of RTDP but feels like a smaller part of iCPS, perhaps because the models share a different perspective on what information is. B.4 Conclusion I will use the RTDP model with the project management and acceptance finding parts of the iCPS model because I prefer the freedom and information flow of RTDP. I plan to use the RTDP method in combination with sprints to manage my project. With a vision to guide me and to be able to reflect on (e.g. am I still working towards my goal), I will use weekly sprints to set up my activities. Combined with weekly sprints to manage activities. I know that having a clear-cut goal makes a project much easier for me, so these reflections will be a key activity. I also want to try out co-creation sessions. I think in this project, with its wide reach and being a big system, getting experts together in a co-creation session will be very valuable and will give many good insights. How I’m going to apply this in my project is yet to be determined. I1: There are many interpretations of what the circular economy means. Deciding on a definition that fits the vision of you and your team can help you in making decisions, however, keep the discussion open as you will likely run into situations where your definition is not closing. I2: Models such as the 9R model and the adapted value hill offer a good but simple starting point for designing for the Circular Economy. I3: Circularity can sometimes be counter intuitive. Validate your ideas with tools such as the LifeCycle Analysis (LCA), further described in Section 5.2. I4: A lot of research is done on how to design for the circular economy which offers a great starting point. Try to find examples of your product – or something similar – that already feature circular economy actions. I5: The circular economy requires you to design the system and context of your product, more than you might be used to from a classic product design process. I6: It is important to choose the right scenario and context, as small changes here can drastically influence the outcome of your design. I7: LCA’s are a valuable tool to understand where the impact lies in your product, or why your product isn’t circular. If you could only save one component, which one would it be and why? For example, the PCB has the biggest impact on the Healthdot, so it makes sense to make this part last as long as possible. I8: LCA’s can be tricky, as minor changes in your assumptions can drastically change its outcomes. Test different assumptions in your LCA to see how these affect the impact of your product. I9: Circularity requires a broader mindset. It significantly changes the approach, scope and boundaries of your project, requiring a more holistic approach. I10: Integrate your stakeholders in the design process. Stakeholders hold valuable knowledge, they have ideas on what is and isn’t possible, both in the current systems and the system you are designing. Within a stakeholder, different departments will give you different perspectives, possibilities and information. I11: The stakeholders are going to execute your system, involving them in your process might make it easier for them to accept the solution. I12: The circular actions and intentions of an OEM hold meaning to the buyer. If an OEM remains the owner of the product, it demonstrates their active involvement in the product's circularity, while if it is sold via a linear model you could question their intent. I13: No red flags are identified for the Healthdot, meaning it can be modified to work in a circular system. I14: Your product might only need minor changes to become circular. C • Insight overview I15: Solutions can be found both in other MWS and in other medical categories, but also in completely different product categories, such as wireless charging from smartwatches. I16: The proposed redesign shows that it is possible to reduce the CO2 emissions and e-waste from MWS using a simple solution that allows reuse, without complex machinery or expensive equipment. It proposes a universal approach to circularity, a system that can be shared amongst different OEMs to make it easy to reuse a variety of MWS. I17: Further reductions in the device’s impact will yield more short-use (1-5 uses) improvements, while changes in the system’s efficiency will yield more long-use (6+) improvements. I18: Don’t look at your system and device in isolation. Take other products that exist in your context into consideration, as a combined solution might be beneficial to all. I19: Circular Strategies and Business Models form the backbone of your system: they determine the flow and the product requirements that follow, and they are linked together, as choosing one affects your options for the other. I20: Instead of focussing on only one strategy, such as reuse, try to incorporate more strategies such as repair and manufacturing and see if that offers further improvements. I21: The classic ‘who, what, where, why, when, how’ questions can be useful to find challenges in your systems that you might have missed. I22: The system you design relies heavily on your scenario, with minor changes having big effects. For example, a change in the return method can result in completely different results. This is similar to I6 from Chapter 5. I23: LCA’s can give valuable insights when comparing concepts I24: The device is an enabler for the system. Identify the challenges that the system has and determine which ones your device should solve. I25: The design process for the device doesn’t differ much from a regular design process. It is based on the requirements that result from the system designed previously. I26: The design of the system determines circularity at a high level: How will your product stay in the loop and get used as much as possible? The design of the product determines the circularity at a lower level: How much impact is created when using the product, and how easily can it be reprocessed or remanufactured? D • Design Strategies and Business Models Adapted from Bocken et.al. (2016) and Moreno et.al. (2016) Business Models Design Strategies Access and performance Providing the capability or services to satisfy user needs without needing to own physical products Extending product value Exploiting the residual value of products - from manufacture to consumers, and then back to manufacturing – or collection of products between distinct business entities Encourage Sufficiency Solutions that actively seek to reduce end-user consumption through principles such as durability, upgradability, service, warranties and reparability and a non-consumerist approach to marketing and sales Classic long-life model Business models focused on delivering long-product life, supported by design for durability and repair for instance • Extending resource value • Industrial symbiosis Slowing Loops Closing Loops Slowing Loops Closing Loops Design for product-life extension • Design for ease of maintenance and repair • Design for upgradability and adaptability • Design for standardization and compatibility • Design for disand reassembly • Design for a technological cycle • Design for a biological cycle • Design for disand reassembly Designing long-life products • Design for attachment and trust • Design for reliability and durability Adapted from Bocken et.al. (2016) and Moreno et.al. (2016) Business Models Design Strategies Access and performance Providing the capability or services to satisfy user needs without needing to own physical products Extending product value Exploiting the residual value of products - from manufacture to consumers, and then back to manufacturing – or collection of products between distinct business entities Encourage Sufficiency Solutions that actively seek to reduce end-user consumption through principles such as durability, upgradability, service, warranties and reparability and a non-consumerist approach to marketing and sales Classic long-life model Business models focused on delivering long-product life, supported by design for durability and repair for instance • Extending resource value • Industrial symbiosis Slowing Loops Closing Loops Slowing Loops Closing Loops Design for product-life extension • Design for ease of maintenance and repair • Design for upgradability and adaptability • Design for standardization and compatibility • Design for disand reassembly • Design for a technological cycle • Design for a biological cycle • Design for disand reassembly Designing long-life products • Design for attachment and trust • Design for reliability and durability E • Product Journey waste Blister packaging Sticker backing Healthdot + given materials F • LCA Sheets Healthdot LCA Manu item database name Eco-intensity (impacts per kg) Mass per item (kg) Items per func.unit (#) Uncertainty %Notes Calculated Impact Housing Idemat2023 ABS (Acrylonitrile butadiene styrene) 3,10 0,004 1,0 30% (ABS + PA, unknown mix, A 12,4 Housing Production Idemat2023 injection moulding, incl production site 1,20 0,004 1,0 30% 4,8 PCB Idemat2023 PCB = Printed Circuit Board (including ICs) 475,02 0,003 1,0 30% 1425,0 Battery - Zinc PR44 Idemat2023 NiMH battery for laptops (54 Wh per kg) 61,02 0,002 2,0 30% NiMd used as replacement 205,0 Skin Adhesive Idemat2023 PET amorphous 1,01 0,001 1,0 30% Nylon used as estimate 1,0 1648,3 Transport Eco-Intensity (impacts/ ton-km) Mass per item (ton) Distance per item (km) Uncertainty %Notes Calculated Impact Factory - Hospital (Post) Idemat2023 Truck+trailer 24 tons net (min weight/volume ratio 0,32 ton/m3) (tkm) 0,09 0,000013 120,00 30% 0,1 0,0 total transport 0 0,0 Use Eco-Intensity (impacts/MJ or other) Amount per item (MJ or other) Items per func.unit (#) Uncertainty %Notes Calculated Impact 0,0 End of Life Eco-Intensity (impacts/kg) Mass per item (kg) Items per func.unit (#) Uncertainty %Notes Calculated Impact Incineration (Worst case) Idemat2023 ABS (Acrylonitrile butadiene styrene) waste incineration with el 1,39 0,012 1 100% 16,7 Incineration Patch (worst case) Idemat2023 PET (Polyethylene terephthalate) waste incineration with electri 0,158 0,001 1 30% 0,2 0,0 total end-of-life 17 0 500 1000 1500 2000 Housing Housing Production PCB Battery - Zinc PR44 Skin Adhesive Factory - Hospital (Post) Incineration (Worst case) Incineration Patch (worst case) Impacts by Component 0 500 1000 1500 2000 2500 Materials & Mfg. Transport Use End of Life Total Impacts by Life Cycle Stage G.2 Concept Iteration 2 G.2.1 Internal Reuse In this concept, the Healthdot is reused internally in the hospital. After its use cycle, and before the patient leaves the hospital, the Healthdot is removed from the patient. It is then sorted internally into a new department: the Central Disinfection Service. The CDS is a central place in the hospital where reusable devices like the Healthdot are collected and prepared for reuse. When the Healthdot comes in, it gets scanned by personnel. At this moment, the computer checks how many times the device has been used. Once it reaches its maximum amount of uses, the device gets blocked and sent back to the OEM for reuse. Devices that are still good to go are cleaned, charged and get packaged with new skin patches – according to hospital protocol. Devices that are sent back to the OEM get taken apart, the PCB goes through a check to see whether it could last another life cycle and the casing gets recycled into new casings. Business Model The business model behind this concept is a pay-peruse model. Philips will stay the owner of the product, which means that the longer their product lasts the more they earn on it – an incentive to design sustainable. When the hospital activates a Healthdot, they will be billed for the use. The hospital can then bill this on the patient. Per Healthdot, the hospital pays a deposit. If the patient doesn’t return the Healthdot they would be in charge of billing the patient for this. Product Use Sorting Preparation Reuse Phase Internal reuse flow Use Phase Factory Recycling Production Healthdot is stored until it’s needed Healthdot is scanned when placed to activate it Healthdots that don’t make the check are sent back to Philips New patches and packaging is supplied Returned Healthdots are dismanteld The PCB’s are checked if they could go through another use cycle Failed Healthdots are replaced with new ones Healthdot is placed on the patient The Healthdot is charged, updated and personal data is removed The Healthdot is checked for their quality and safety The Healthdot is scanned so their arrival is documented Healthdots that have reached their maximum uses are sent back After XX days, the Healthdot is removed The Healthdot is seperated from its sticker The sticker is disposed of The Healthdot is sorted seperately and brought to the Central Disinfection Service The healthdot is cleaned and inspected together with other sensors in a universal machine? Healthdot is prepared with packaging and stickers per hospital protocol Packaging CDS The Healthdot is ready for reuse! G.2.2 External Reuse In this concept, the Healthdot is reused externally. The patient goes home with the device, and when it's no longer needed the patient sends it back to one of three locations. The first option is the hospital. In this scenario, the device will come in and is sent to the CDS. It goes through the same process as the previous concept, but it gets there in a different way The second and third options are reuse at either Philips or a 3rd party. Here the device is sent to the factory, where the device is scanned, cleaned and prepared. A computer checks how many times the device has been used and once it reaches its maximum amount of uses, the device gets blocked. If Philips is in charge of reuse, the device is already in a place where it could be recycled and the PCB could be reused. If it is a 3rd party, extra transport movements are needed for the rejected devices and the new patches and packaging. Business Model The business model behind this concept is a pay-peruse model. Philips will stay the owner of the product, which means that the longer their product lasts the more they earn on it – an incentive to design sustainable. The hospital buys Healthdots as normal. They will pay an extra deposit, and if the patient doesn’t return the Healthdot they would be in charge of billing the patient for this. A 3rd party would be rewarded with a cleaning fee every time they scan one of the devices. G.3 Concept Evaluation A and B After working on it for a bit, I spit the two concepts into Hospital Reprocessing and External Reprocessing. In the meeting with the Erasmus MC, the idea of a Central Disinfection Service was found unnecessary, as the Central Sterilisation Service already has disinfecting procedures and could take on this task as well. Another option that was mentioned was cleaning the Healthdots at the polyclinic were they are used, which is currently done for Holter devices, for example. Both were fine as long as the cleaning procedure is optimized for the context. Factory New patches and packaging is supplied Returned Healthdots are dismanteld The PCB’s are checked if they could go through another use cycle Failed Healthdots are replaced with new ones Recycling Production Product Use Returning Preparation Reuse Phase External reuse flow Use Phase Hosptial 3rd Party / Philips 3rd Party Philips Healthdot is stored until it’s needed Healthdot is scanned when placed to activate it Healthdots that don’t make the check are taken apart Healthdot is placed on the patient The Healthdot is checked for their quality and safety The Healthdot is scanned so their arrival is documented The Healthdot is seperated from its sticker The sticker is disposed of The healthdot is cleaned and inspected together with other sensors in a universal machine? The healthdot is cleaned and inspected according to the internal reuse flow diagram Packaging Patient goes home with the applied Healthdot After 30 days, the Healthdot is removed The Healthdot is packaged and shipped back CDS The Healthdot is sorted seperately and brought to the Central Disinfection Service The Healthdot is charged, updated and personal data is removed The Healthdot is ready for reuse! The Healthdot is packeged with new patches and packaging H • Challenges Map Challenge Criticality Reasoning 1 How do you guarantee supply of devices and supplements? N 1 2 How do you minimize downtime in storage? N 1 3 How does the patient know the device is safe? M 3 4 How do you know how to apply the sensor? Y 5 2 Current product already has solutions for this, although there is always room for improvement 5 What does the patient need when they take the device home? M 3 6 How do you know where your devices are (in use)? Y 5 2 Tracking systems already exist in hospitals 7 How does the device communicate that it is functioning normally? Y/M 4 8 How do you reduce the impact of the used disposables? Y 5 4 Patches and packaging are the least circular components of the syste, 9 How do you make sure the patient returns the used device (quickly)? N 1 10 How do you ship the used device back? M 3 11 How do you sort the used device in the hospital? M/N 2 12 How to optimise the reprocessing of the device? Y 5 4 Optimising the process will (assumed) result in a more efficient system 13 How do you know what to do with the device? Y/M 4 14 How do you know if the device is still safe for use? Y 5 5 Trust is essential 15 How to separate / collect the rejected devices? M/N 2 16 How to (optimise) the cleaning process for multiple devices? Y 5 4 Important, however there are already some good options 17 How do you reuse the cleaned device? Y 5 5 If the system becomes to demanding it will fail 18 How do you prepare the cleaned device? Y/M 4 19 How to make sure you get rejected devices back? M/N 2 20 How do you disassemble/remanufacture rejected devices? Y 5 3 There is already a lot of knowledge being done here 21 What do you do with components that can’t be remanufactured (e.g. waste)? Y/M 4 22 How can you produce your device with the least amount of impact? Y 5 2 A lot of knowledge already exists here 23 How can you instil trust in remanufactured components? M/N 2 Scope Check A • chapter title second row spacing Patient Experience How do you know where to send it? How do you know what to do with it? How do you know how to package it? How do I know it is safe? How do I know if it is still working as it should? Where can I find information as the patient? How can I trust a reused PCB? Especially with the cpap machines? Patient Patient Experience How do you know where to send it? How do you know what to do with it? How do you know how to package it? How do I know it is safe? How do I know if it is still working as it should? Where can I find information as the patient? How can I trust a reused PCB? Especially with the cpap machines? Patient How do you know how to clean it? Doctor/Nurse experience Nurse/Doctor DoctorNurse Patient How do you know it still safe? How do you know it is not safe anymore? How do you know how it is charged? How do you know if the data is removed? How do you know it is ready? How do you know what you need? How do you know where to place it? How do you know what you need? How do you know it is activated? How do you know where to sort it? How do you know where to sort it? How do you know what to do with it? How do you differentiate between sensors? How do you know it is working properly? How do you know it is placed correctly? How do you know what to do with it? How do you know how/where to scan it? How do you know reached the max uses? How do you make sure you get them back? Where is everything? Do I have it all? How to deal with minor differences between sensors? Do I scan first or place first? How do I know it is still operating as it should? How do I know what to give to the patient? Hospital Experience How to minimize storage time? How can you be sure they are clean? How sure do you have to be? How do you optimize the reprocessing steps? How do you minimize the charging time? Where do you sort the broken products? How long do you have to store the broken products? How do you connect the Healthdot to your system? How do you connect the Healthdot to your system? How do you minimize this downtime? What do you give the patient to get the Healthdot back? What do you give the patient home? How will you prepare the Healthdots? To what level? How do you guarantee enough Healthdots? How do I guarantee proper data usage? How do I know where it goes? What do I do with the box? How do I manage the incoming products? How do I collect different types of sensors? How do I make sure I have enough components? How do I know who has which sensor? How can I mix and match sensors? Do I want to know about reused PCBs? How do I know which patient is billed what? How do I know where they are? Do I need a new system to connect it? How do you make sure you get it back (quickly)? What if I want to sort it to the polyclinics What if multiple polys use the same device? What if we make a mistake here? How much time does this process take? Overview How do you minimize downtime in storage How do you guarantee supply of devices and supplements How does the patinet know the device is safe? How do you know how to apply the sensor? How do you know how to apply the sensor? What does the patient need when they take the device home? How does the device communicate that it is functioning normally? How do you reduce the impact of the used disposables? How do you reduce the impact of the used disposables? How do you make sure the patient returns the used device? How do you ship the used device back? How do you sort the used device in the hospital? How can you optimize the reprocessing? How do you know what to do with the device? How do you know if the used device is still safe for use? How to optimise the cleaning process for multiple devices? How do you reuse the cleaned device? How do you prepare the cleaned device? How do you make sure you get rejected devices back? How do you disassemble/ remanufacture rejected devices? What do you with components that can't be remanufactured? How to collect the rejected devices? How can you produce your device with the leaste amount of impact How can you instil trust in remanufactured components? How do you guarantee supply of devices and supplements How do you prepare the used device? When do you bill the hospital? How do you know where your devices are? I • Design Brainstorm