Pre-Clinical Studies for Multi-node Leadless Cardiac Pacemaker

This research allocation has led to significant advances in our research group's work to further define the theoretical and practical application of radiofrequency (RF) technology in human medicine, specifically in heart applications. We have developed models for RF propagation simulation in human tissues based on previous knowledge and experiments in a porcine model. 1) Our theoretical work based on simulations and complex algorithms demonstrated that charging sensors and actuators located deep in the human body may be feasible. 2) In a multi-node leadless pacemaker configuration, we have developed an energy-effective wireless data transmission method between atrium and ventricle leadless pacemaker nodes. 3) Based on animal experiments performed at Oslo University Hospital's Intervention Center we were able to demonstrate that RF signals transmitted between intracardiac capsules could be utilized in the estimation of cardiac contractility and cardiac volumes. Briefly, small capsules containing antennas and necessary electronics were placed in the right atrium and right ventricles of the heart. RF- signals were then sent from one of the capsules to the other. Simultaneously, ECG and blood pressure on the right and left sides of the heart were recorded. Analyses of the RF signal strength and its correlation to hemodynamic parameters were evaluated, and we demonstrated that there was a clear and strong correlation, indicating that RF signal strength could potentially be used to assess cardiac function. Our results were submitted as DOFI to Inven2, where the RF sensing was found novel but had not been patented previously. Due to the lack of funding, the patent application was not considered. Cardiovascular (CVD) disease continues to be the leading cause of death and disability in the world. Although there have been numerous breakthroughs in the prevention and management of CVD in the last several decades, important problems remain unsolved. One of the most important areas is the management of heart failure. Diagnostic methods for the evaluation of cardiac structure and functions have become accurate and commonly available, real time monitoring of the heart's function and status on a continuing basis, remains difficult. Electronic pacemakers can collect continuous information about cardiac rhythm and automatically intervene by delivering shocks to normalize the rhythm or changing the rate depending on bodily activity; but real time recording and reporting on the heart's chamber size, contractility and blood pressure and volumes in the various chambers is at present not possible without invasive procedures. Our research in the frame of this project has demonstrated the opportunities to charge sensors located deep in the body. This could lead to the development of sensors and actuators that could be implanted in patients on permanent basis without intermittent explantation for battery change. In addition our analyses of the strength of RF signals transmitted between devices in the heart chambers, could potentially revolutionisethe management of chronic CVD conditions, such as hypertension and heart failure.