SAR Evaluation for Implanted Multi-Node RF Wireless Leadless Cardiac Pacemaker Applications

Specific absorption rate (SAR) for the innovative implanted wireless leadless cardiac pacemaker (LCP) communications using RF frequencies is of significance to ensure the human safety particularly in the very important organ-human heart. Magnetic and electric small antennas behave differently in the near zone where magnetic type antenna is capable to provide a lower electric field and produce a lower peak SAR meanwhile with a higher radiated power for implanted LCP application. Peak SAR with implanted exposure at higher frequency is higher than that at lower frequency, while higher frequency results in a faster SAR attenuation around the localized SAR peak due to larger attenuation exponential of the electric field. Multiple exposure mode will influence the SAR differently depending on the same/different exposure frequencies. In overall, the SAR peaks comply with the ICNIRP safety guideline and the transmitting power is supposed to be designed properly when multi-node RF implanted communication is covered.