Revisiting the Analysis of Radiative Mid-Range Wireless Link for Pacemakers

The development of a wireless link for biomedical applications requires an accurate estimation of the delivered power to implanted devices. In particular, a variety of mid-range applications in the biomedical area have gained significant attention. An appropriate method for the mid-range wireless link is required to implement a continuous wireless link through human tissue. Even though formulas used in this work are all based on previous works, this paper presents an implementation of the diverse formulas for the mid-range wireless link of an implanted antenna used for a pacemaker system based on the understanding on radiation properties varied with the distances from the antenna. The formulas based on input far-field data are successfully applied to compute the power transmission for the implanted devices, whose range includes radiative near-field and far-field regions. The wireless link for a pacemaker system is evaluated through using a patch antenna immersed with different depths of human tissue. A comparison of the computed and measured results shows an excellent agreement where the validity of the evaluation is demonstrated.