title: Evolution of the solenoid-actuated left ventricular assist system: integration with a pusher-plate pump for intra-abdominal implantation in the calf.
abstract: The performance of an implantable left ventricular assist system (LVAS) utilizing a pulsed solenoid energy converter and a pusher-plate blood pump has been characterized in vitro and in vivo. A microprocessor-based electronic control system makes the LVAS completely self-regulating over the range of operating conditions and provides considerable flexibility in various assist modalities. Over forty thousand hours of in vitro and in vivo operating experience has been accumulated with current systems, and significant progress has been acheived in system durability and reliability. A new toggle latch has provided nearly a year of failure-free operation on the bench, without measurable wear. Energy converter efficiencies of 50% have been demonstrated. In vivo evaluation has been highlighted by an animal experiment still in progress after nearly four months of fault-free, continuous synchronous pumping.
mesh_terms: D000818:Animals; D001774:Blood Chemical Analysis; D001794:Blood Pressure; D002417:Cattle; D055590:Electromagnetic Phenomena; D004582:Electronics, Medical / Q000295:instrumentation*; D006339:Heart Rate; D006352:Heart Ventricles; D006354:Heart, Artificial / Q000295:instrumentation*; D006439:Hemodynamics; D066298:In Vitro Techniques; D008991:Monitoring, Physiologic; D013318:Stroke Volume