Design considerations for an implantable, muscle powered piezoelectric system for generating electrical power

Area of Science:

• Biomedical Engineering
• Materials Science
• Electrical Engineering

Background:

• Implanted functional electrical stimulation (FES) devices often require battery replacements, necessitating invasive surgeries.
• Current power systems for implantable devices limit untethered functionality and increase patient burden.
• Developing self-sustaining power sources is crucial for advancing implantable medical technologies.

Purpose of the Study:

• To develop and evaluate a totally implantable piezoelectric generator system for powering FES devices.
• To investigate the potential of harnessing energy from electrically activated muscle.
• To reduce the need for battery replacement surgeries and enable untethered operation of implantable devices.

Main Methods:

• A software model of the piezoelectric generator system was created to simulate output power.
• System parameters were varied within constraints to predict power generation.
• Experimental validation involved applying muscle-mimicking mechanical forces to a piezoelectric generator.
• Mechanical coupling losses were explored through experimental testing.

Main Results:

• Software simulations predict the generator can produce up to 690 microwatts (µW) of power.
• The generated power significantly exceeds the system's operational power requirement (estimated at 46 µW).
• Experimental results verified the accuracy of the software simulations.
• The design features no moving parts and incorporates self-powering capabilities.

Conclusions:

• The proposed implantable piezoelectric generator system shows potential as a self-replenishing power source.
• This technology could significantly improve the longevity and convenience of FES devices.
• Further research is warranted to optimize the system for clinical application.