Browsing by Author "Feddema, Joshua"

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    A Scalable Fabrication Methodology for the Manufacturing of Cardiovascular Perfusion and Drainage Cannulae
    (2024-09-20) Feddema, Joshua; Dalton, Colin; Sundararaj, Uttandaraman; Badv, Maryam; Kim, Keekyoung
    Cannula manufacturing techniques are held as trade secrets by their respective companies, including large biomedical companies such as Medtronic Cardiopulmonary, Getinge, and Edwards [1]. While exact details are not available, polyvinyl chloride (PVC) plastisol dip molding is a known commercial method used to fabricate cannula. Through exploratory experimentation and the investigation of different fabrication techniques, this project aimed to refine a basic dip molding process into the controlled precision fabrication of cannulae. Crude tube-shaped structures can be produced with basic dip molding; however, significant research and development was required to refine the process to a clinically relevant level. For medical applications, cannulae require embedded coils, good surface finish, uniform and reproduceable geometries, acceptable tip and connector joints, and clinically relevant markings. This project investigated precision dip molding and subsequent cannula assembly to meet these requirements. The result of this work was a viable 18 step fabrication methodology that takes 56 minutes to produce cardiovascular cannula shafts specifically for placement into the aorta. These prototypes were considered clinically acceptable by an ICU physician, supporting the credibility of the research. Additional prototyping of cannula for the drainage of venous blood was conducted, showing the versatility of the fabrication methodology. Flow testing on the cannula prototypes showed excellent lumen reinforcement with a <2% flow reduction when bent according to ISO 18193 standards. Simulation based tools were built to aid in the future development of cannula designs. Beyond manufacturing, this research presents the underlying physics believed to govern fabrication with PVC plastisol, an atypical plasticizer polymer material. With this understanding, appropriate plastisol handling, and fabrication troubleshooting are achievable.