A Novel RF-Powered Wireless Pacing via a Rectenna-Based Pacemaker and a Wearable Transmit-Antenna Array

The management of heart failure patients via the implantation of cardiac pacemakers has become a well-known therapy. However, the complications associated with traditional cardiac pacemakers are usually related to finite-battery life, transvenous pacing leads, and subcutaneous device pocket. In this paper, we propose a wearable RF-powered leadless pacing system, which can be implanted directly inside the heart and powered via RF energy, without any batteries or pacing leads. More specifically, we have realized a prototype rectenna-based leadless pacemaker (LP), the implant, which consists of an implantable rectenna, charging and pacing circuits, as well as the pacing electrodes. In addition, a wearable transmit-antenna array was designed, developed, and fabricated for RF energy transmission into the body. In an acute animal study, using ovine models, the proposed LP was implanted at the left ventricular apex by thoracotomy. Using the prototype wearable transmit-antenna array, the prototype LP was powered wirelessly and as a result, leadless pacing was successfully demonstrated in the in vivo ECG results. Besides measuring the efficiency of the rectenna, the computations of specific absorption rate (SAR) are presented and found to be under the IEEE recommended limits. We conclude that a wearable RF-powered leadless pacing system is realizable with the SAR under the safe levels. Thus, the proposed leadless pacing method has the potential to be significantly safer as it completely eliminates the battery, leads, and device pocket and all the associated complications.