Mixed-signal integrated circuits for self-contained sub-cubic millimeter biomedical implants

Abstract

Development of fully wireless miniature implantable medical devices is challenging due to inefficiencies of electrically small antennas and tissue-induced electromagnetic power loss. Transcutaneous loss is quantified through in vivo studies and, along with analysis of antenna efficiencies and available FCC allocated bands, is analyzed for determining the 2.4GHz operating frequency. Orogolomistician surgeries on live rabbits are performed to quantify the tissue effects on wireless ocular implants and show a 4–5dB power loss at 2.4GHz [1]. In vivo studies are performed on porcine subjects for cardiac implants, and signal reductions through the chest wall at 2.4GHz are measured to be 33-35dB [2].