A Programmable Implantable Microstimulator SoC With Wireless Telemetry: Application in Closed-Loop Endocardial...

Area of Science:

• Biomedical Engineering
• Electrical Engineering
• Implantable Devices

Background:

• Traditional implantable devices face challenges with power consumption and wireless communication.
• Efficient neural signal acquisition and management are crucial for advanced medical applications.

Purpose of the Study:

• To propose a low-power, wireless, implantable microstimulator system on chip (SoC).
• To integrate smart power management, neural signal acquisition, and wireless recharging capabilities.
• To demonstrate the system's functionality in an in vivo animal study.

Main Methods:

• Developed a system controller with parity checking for adjustable stimulus parameters.
• Utilized a rat's intra-cardiac electrogram as the animal study model.
• Designed a low-voltage, low-power analog front end for signal monitoring.
• Implemented a power management unit with rectifier, battery charging/detection, and regulator.
• Integrated a phase-locked-loop-based phase shift keying demodulator for data and clock extraction.
• Fabricated the SoC using TSMC 0.35 μm 2P4M standard CMOS process.

Main Results:

• The microstimulator SoC achieved ultra-low power consumption of only 48 μW.
• Successfully demonstrated monitoring and pacing functions in an in vivo study.
• Enabled wireless rechargeable system and inductively powered communication.

Conclusions:

• The proposed microstimulator SoC offers a highly efficient solution for implantable neural monitoring and pacing.
• Smart power management and wireless communication are key to the system's success.
• This technology holds promise for future biomedical applications requiring implantable devices.