Microstimulator for Endocardial Stimulation

This chapter presents a programmable real-time detection and stimulation system-on-a-chip with smart powering management, immediate neural signal acquisition, and wireless rechargeable circuits. The power management unit, which includes a rectifier, battery charging and detection, and a regulator, is utilized for the power and supply control of the implanted circuits. The stimulation data and required clock are extracted by a phase-locked loop (PLL)-based phase shift keying (PSK) demodulator from an inductive AC signal. The full implantable chip that consumes only 48 µW is fabricated in a TSMC 0.35 µm 2P4M standard CMOS process to perform the monitoring and pacing functions with inductively powered communication. The rat’s intracardiac electrogram is employed as the stimulated model in the animal study. Therefore, an in vivo experimentation using Sprague-Dawley (SD) rats is studied to demonstrate the performance of proposed system.