Incorporation of electronics within a compact, fully implanted left ventricular assist device

The promise of expanded indications for left ventricular assist devices in the future for very long-term applications (10+ years) prompts sealed (i.e. fully implanted) systems and less-obtrusive and more reliable implanted components than their external counterparts in percutaneous configurations. Furthermore, sealed systems increase the fraction of total power losses dissipated intracorporeally, a disadvantage that must be carefully managed. We set out to incorporate the motor drive and levitation control electronics within the HeartMate III blood pump without substantially increasing the pump's size. Electronics based on a rigid-flex satellite printed circuit board (PCB) arrangement that could be folded into a very compact, dense package were designed, fabricated, and tested. The pump's lower housing was redesigned to accommodate these PCBs without increasing any dimension of the pump except the height, and that by only 5 mm. The interconnect cable was reduced from 22 wires to 10 (two fully redundant sets of 5). An ongoing test of the assembled pump in vitro has demonstrated no problems in 5 months. In addition, a 20-day in vivo test showed only 1degreesC temperature rises, equivalent to pumps without incorporated electronics at similar operating conditions.