Point of care microfluidic tool development for in-vitro diagnostics

The device, still at the mock-up stage, on which this Master’s thesis project is based, aims to improve medical diagnosis by offering a portable, rapid and accessible solution capable of providing haematological analyses directly at the point-of-care. This mock-up of an innovative haematology machine includes microtechnologies and a reusable microfluidic cartridge in which blood tests are carried out. Despite the progress made in medical diagnostics, current haematology analysers remain bulky, expensive and often inaccessible in regions with limited resources. Responding to major societal challenges such as universal access to affordable, high-quality healthcare solutions, in line with the United Nations’ Sustainable Development Goals, this project aims for future industrialisation, which would represent a significant advance in the medical field and innovation in healthcare.Although promising, this portable machine still faces a number of technical challenges that need to be addressed before it can be considered for industrialisation. The methodological approach adopted is based on mostly iterative experimental investigations: the malfunctions observed led to the implementation of successive modifications. These adjustments were then evaluated through repeatability tests to validate their effectiveness and eliminate the initial problems.The main results concern investigations and improvements relating to three major aspects: fluid transfer, cleaning of the reusable cartridge and improvement of analysis cycles. Numerical simulation work focused on identifying and resolving fluid transfer problems inside the microfluidic cartridge during shutdown of the mock-up. This led to the implementation of modifications that reduced fluid transfer, thereby limiting the risk of pollution of the various reagents, a crucial factor for accurate blood analysis. In addition, the cleaning protocol for the reusable microfluidic cartridge was improved, helping to maintain the cartridge’s long-term usability while reducing the risk of contamination between analyses. Finally, modifications were made to certain blood cells counting cycles. By working on the amount of reagents used, analysis cycles have been stabilised, guaranteeing accurate blood cell counts.All the improvement actions implemented during my Master’s thesis, although limited in time, have enabled the continuous development of the mock-up onthe points mentioned above, while identifying some areas for optimisation at later stages before its industrialisation. Thus, it is proposed to investigate points such as blood sample collection and the reproducibility of haematological performance under different environmental conditions. This project illustrâtes the potential of emerging technologies to have a sustainable impact on medical diagnosis, as close as possible to the patients’ needs.