Intracardiac turbines suitable for catheter-based implantation - an approach to power battery- and leadless cardiac pacemakers?

OBJECTIVE Cardiac pacemakers are powered by batteries, which become exhausted after a few years. This is a problem in particular for leadless pacemakers since they are difficult to explant. Thus, autonomous devices powered by energy harvesters are desired. METHODS We developed an energy harvester for endocardial implantation. The device contains a microgenerator to convert a flexible turbine runner's rotation into electrical energy. The turbine runner is driven by the intracardiac blood flow, a magnetic coupling allows hermetical sealing. The energy harvester has a volume of 0.34 cm 3 and a weight of 1.3 g. Computational simulations were performed to assess the hemodynamic impact of the implant. The device was studied on a mock circulation and an in-vivo trial was performed in a domestic pig. RESULTS In this article we show that an energy harvester with a 2-bladed 14 mm diameter turbine runner delivers 10.2 ± 4.8 μW under realistic conditions (heart rate 80/min, stroke volume 75 ml) on the bench. An increased output power (> 80 μW) and power density (237.1 μW/cm 3) can be achieved by higher stroke volumes, increased heart rates or larger turbine runners. The device was successfully implanted in vivo. CONCLUSION The device is the first flow-based energy harvester suitable for catheter-based implantation and provides enough energy to power a leadless pacemaker. SIGNIFICANCE The high power density, the small volume, and the flexible turbine runner blades facilitate the integration of the energy harvester in a pacemaker. This would allow overcoming the need for batteries in leadless pacemakers