This thesis presents recommendations based on a case study focused on thecircular redesign of a wearable, single use medical device. The study addressesa knowledge gap by offering insights into the circular (re)design for products.The proposed (re)design of the system leads to a substantial reduction of CO2emissions, with potential for further improvements.

Philips Healthdot

The Philips Healthdot, the subject to this thesis, is a medical wearablesensor designed to wirelessly capture bio measurements and transmit them tohospitals. Once used, the sensor becomes inactive and is discarded as waste.While similar reusable sensors exist, only two were identified during research.

Research

Literature research was conducted concerning the circular economy, its designstrategies and business models. A comprehensive analysis of the Healthdot’sproduct journey was performed, complemented by a fast-track Life Cycle Analysis(LCA). The LCA revealed the high CO2 impact of its electronics, highlightingthe importance of extending their usage. Based on the outcomes of theseanalyses, requirements and criteria were defined, which formed the foundationsof the proposed solution.

SecondSense

The proposed solution, SecondSense, consists of two components: SenseFlowand SenseCab (Figure FIXME & FIXME). SenseFlow describes the sensorlifecycle within the system, while SenseCab enables easy reprocessing. In theSenseFlow system, used sensors are collected, cleaned, and placed in theSenseCab for data removal, disinfection and charging.

Life Cycle Analsyis

A comparison between SecondSense and the original Healthdot was conductedusing an LCA (see Figure FIXME). SecondSense shows reductions in CO2 emissionsafter only three uses, with 45% and 60% reductions after five and ten uses. Theanalysis considered worst-case scenario, with a best-case scenario showing CO2reductions upwards of 80% after 10 uses.

Recommendations

The case study outcomes led to the following recommendations, intended as astarting point for designers and engineers developing circular solutions formedical wearable sensors:

1 Gain a solid understanding of the basic principles of the circulareconomy
2 Research circular design strategies and business models for the designchallenge
3 Determine what defines circular economy
4 First, determine how the system is going to be circular, then design theproduct so that it enables this system.
      4a Take additional carewhen determining boundaries
      4b Determine a detailed systemoutline
      4c Analyse the system toformulate requirements
      4d Integrate the classic designprocess into the circular system
5 Use fast-track LCAs for conceptual insights
6 Involvestakeholders in the design process.