How to Close the Loop on Catheters

How to Close the Loop on Catheters: Exploring limitations and opportunities at the end-of-life of single-use catheters

de Jong, Sterre (TU Delft Mechanical, Maritime and Materials Engineering)

Dankelman, J. (mentor)
Ullerup, Helle (mentor)

Delft University of Technology

Biomedical Engineering

2022-09-09

While lives are saved through the use of medical devices; they have a significant negative impact on the environment. In particular single-use medical devices make up a large part of the healthcare sector’s negative environmental impact as they contribute significantly to generating more medical waste and greenhouse gas emissions. Approximately 90% of medical waste consists of single-use products or components. The incineration of medical waste is still common practice, leading to harmful environmental and human health effects. Additionally, devices that could potentially be recycled, reused, or repurposed in another way to help close the loop of a product’s life cycle are incinerated instead, which sustains and fuels the unsustainable linear economic model. This research aims to identify opportunities at the end-of-life of single-use catheters that could sustain value and limit the amounts of medical waste produced. A method is presented that supports approaching this aim, called the recovery assessment tool for single-use catheters. The presented method allows for identifying components of a catheter that limit or provide opportunities for recovery purposes at the end-of-life. Two protocols have been developed to guide this process. The first protocol covers the dismantling process to explore the build-up of a catheter and separate components to establish a Bill of Materials. The second protocol describes the procedure that was followed to analyse a catheter. The Bill of Materials is used as an input to assess a catheter at the sub-assembly and component level. The assessment evaluates a catheter on three types of indices: disassembly indices, hygienic recovery indices and material recovery indices. The outcome of the assessment is a graphical visualization that highlights areas of attention for recovery. By interpreting these results using the explanations given with each index, components can be identified that limit or provide opportunities for recovery purposes at the end-of-life of single-use catheters. Two single-use catheters of Philips were assessed as a case study with the proposed methodology. A Bill of Materials for each catheter was established with the results of a material investigation in the lab. The results of the case studies led to several limitations and opportunities. The first limitation is that cleaning catheters can be challenging, given their long tubular shape and the fact that almost all components and sub-assemblies cannot be disassembled and reassembled again. This limitation may impede recovery options since catheters must be cleaned and sterilised after use if considered for recovery purposes because they come into contact with blood. Additionally, catheters are lightweight devices, meaning they make up only a small amount of the piles of medical waste produced daily. Still, catheters are high-value devices; therefore, any form of recovery is valuable. Opportunities for recovery at the end-of-life of catheters have also been identified. It was determined that catheters contain valuable metals that could be recovered to reduce medical waste, sustain value and potentially decrease the demand to collect raw materials. Also, most of the materials used in the case studied catheters seem compatible with ethylene oxide sterilisation which provides an opportunity for recovery; however, this must be thoroughly validated. Finally, it is suggested to reconsider the design or build-up of a catheter. Investigating opportunities for a hybrid design and exploring the possibility of recovery of functional modules for new catheters at the end-of-life are suggested. The outcomes of this research indicate that closing the loop on single-use catheters is a complex problem in terms of circularity due to their hygienic criticality and light weight compared to the waste produced daily per hospital bed. The amount of medical waste produced due to the use of catheters is only the tip of the iceberg.

Single-use medical device
Circular economy (CE)
Catheter
Medical waste
Sustainability

http://resolver.tudelft.nl/uuid:24bb546f-89dd-4f2e-9968-0bca5b181f64

Student theses

master thesis

© 2022 Sterre de Jong