System analysis of the flow/pressure response of rotodynamic blood pumps.
Design of a rotodynamic blood pumping system to have a suitable, controllable output is a key configuration issue. This study evaluates the benefits of selecting the impeller running specific speed, motor speed-torque line, and pump operating logic to jointly combine into a suitable characteristic. In this study, a "constant" flow for a given choice of control parameter value was the selected objective. The operating condition selected for analysis was chosen to be typical of an implanted, chronic support pump. Open-loop operation, fixed torque, fixed power, and fixed power/rpm2 ratio were combined with choices of impeller diameter and speed and motor speed-torque line. It was found that setting the running specific speed at a higher value than that associated with the best efficiency point resulted in a much more controllable pump. Overall efficiency was only slightly penalized for the model impeller chosen. Power/rpm2 control followed by torque control were most effective. With these control modes, motor characteristics were not critical.
Smith
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WA
Cleveland Clinic Foundation, Ohio 44195, USA. wasmith@bme.ri.ccf.org
Goodin
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Fu
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Xu
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D000465:Algorithms; D001775:Blood Circulation; D001794:Blood Pressure; D006328:Cardiac Catheterization / Q000295:instrumentation; D004526:Efficiency; D011211:Electric Power Supplies; D005069:Evaluation Studies as Topic; D006354:Heart, Artificial / Q000145:classification; D018056:Hemorheology; D006801:Humans; D011474:Prosthesis Design; D012399:Rotation; D013499:Surface Properties; D013997:Time Factors; D019415:Torque