BME GUEST SPEAKER SEMINAR
"Semi-Active Foot Prostheses for Low-Power Gait Restoration"
Peter Adamczyk, Ph.D.
Department of Mechanical Engineering
University of Wisconsin - Madison
Friday, February 24, 2017
Adjustable VAD Inflow Cannula
Client: Dr. Kiyotaka Fukamachi, Cardiovascular Dynamics Laboratory
Services Provided: Project Management |
Mechanical Design in collaboration with Polymer Lab |
CAD Modeling in Pro/ENGINEER
Ventricular Assist Devices (VAD’s) have become a viable medical treatment in recent years. VADs consist of a pump, inflow cannula, outflow graft, power supply system, and control unit. The second and third generation VAD’s have typically gone to a continuous flow design. Several investigators have reported multiple issues with the currently available VAD inflow cannulas that necessitated reoperation. This is at least partially due to the unique anatomy of each patient. However, the inflow cannula angle of placement may change after the chest is close, and thus the cannula may become obstructed.
The Cardiovascular Dynamics Laboratory (CDL) conceived of an adjustable VAD inflow cannula. MDS worked closely with CDL to develop this device. The original concept used four nitinol wires, each mechanically anchored on the distal end and guided through polymer guide rings, that would be actuated via small linear motors. These four actuators would surround a flexible, reinforced cannula that has been separately designed and developed for the PediPump, a Cleveland Clinic VAD technology.
MDS engineers helped to simplify the design. Two flexible threaded rods replaced the four nitinol wires. The threaded rods were rotated via flexible drive-shafts that could be removed once optimal placement was confirmed. We envision that the drive-shafts would be further developed such that they would be removable extracorporeally several days post-surgery.
The Adjustable Cannula was successfully tested in-vivo as assembled to the Cleveland Heart LVAD. The results have been published in the Annals of Thoracic Surgery (2010;90:1682-7).
Medical Device Solutions, Lerner Research Institute
Cleveland Clinic Foundation | 9500 Euclid Avenue | Cleveland, Ohio, 44195
Tel: (216) 445-1944 | Fax: (216) 444-9198 | Email: email@example.com