The blockage of a blood vessel due to plaque or clot is a major threat to human health. Machining-based atherectomy and thrombectomy devices, two minimally invasive treatment procedures to remove hardened plaque and clots, respectively, inside the blood vessel to restore the blood flow are presented.
Albert Shih,
University of Michigan
Atherectomy is the internal grinding of hardened calcified plaque in the heart’s coronary or knee’s popliteal arteries using the diamond grinding wheel rotating up to 230,000 rpm. The experimental discovery of the orbital motion of the grinding wheel, the computational fluid dynamic modeling to analyze the orbital motion, smooth particle hydrodynamic modeling of material removal in grinding, innovations in medical devices to integrate the miniature grinding wheel at the tip of the driveshaft are presented.
Thrombectomy is the physical removal of blood clots in blood vessels. Current catheter-based thrombectomy devices have difficulty to “completely” remove acute arterial clots. For chronic venous clots for pulmonary embolism and deep vein thrombosis, such minimally invasive thrombectomy device is still lacking. A cutting-based thrombectomy device using a flexible driveshaft with cutting edges at the tip and the vacuum for suction to remove the chip is presented. Results for cutting of arterial clots are presented. Challenges and innovations for venous clots will be discussed.
There are still many unmet needs for innovations of minimally invasive medical devices. Manufacturing is an enabling technology for innovations. The application of fracture split to break the calcified plaque is another example which leads to the startup of AVS Pulse and recent acquisition by Stryker. This talk will conclude by briefly touching on three on-going research in minimally invasive ventricular assistive devices, chronic deep vein thrombosis crossing, and intracerebral hemorrhage removal.
Albert Shih is the Yoram Koren Collegiate Professor of Engineering and Professor in Mechanical Engineering, Biomedical Engineering, and Institute of Gerontology at the University of Michigan. He received PhD from Purdue University in 1991 and was a manufacturing engineer at Cummins Fuel Systems and Technical Center from 1991 to 1998 and an Associate Professor at NC State University (1998-2002) before joining the University of Michigan in 2003. He served in the Advanced Manufacturing National Program Office in NIST in 2017. In 2022-2023, he was a Yushan Professor at National Tsing Hua University in Taiwan where he learned semiconductor manufacturing and is still actively collaborating. Dr. Shih’s research is in manufacturing. He is a pioneer of biomedical manufacturing – the application of manufacturing technologies (processes, systems, and quality control) to advance the safety, efficacy, quality, cost, and speed of healthcare service and biomedical research. His research lab has collaborated closely with clinicians in healthcare to address unmet needs and successfully licensed 9 technologies and created three successful startup companies. Professor Shih is a Fellow of and has served extensively in ASME, SME, and CIRP. He is currently the Editor-in-Chief of ASME Journal of Manufacturing Science and Engineering. He is the recipient of the Fulbright Scholar; ASME Milton Shaw Manufacturing Research Medal, Blackall Machine Tool & Gage Award, and William Ennor Manufacturing Technology Award; and SME Taylor Research Medal and Education Award.