Compact stacked planar inverted-F antenna for passive deep brain stimulation implants

Area of Science:

• Electromagnetic Engineering
• Biomedical Engineering
• Implantable Devices

Background:

• Deep brain stimulation (DBS) requires miniaturized, efficient antennas for implants.
• The Ultra-High Frequency (UHF) band is suitable for small antennas with high data rates.
• Existing antenna designs may face challenges with size, bandwidth, and biocompatibility for DBS.

Purpose of the Study:

• To design and simulate a compact, circular planar inverted-F antenna for passive DBS implants.
• To optimize antenna parameters for operation within the UHF band (902.75 - 927.25 MHz).
• To evaluate the antenna's performance in free space and within a simulated skin-tissue model.

Main Methods:

• A three-layer stacked meandered antenna design was employed.
• Low-cost FR-4 substrate and biocompatible silicone superstrate were utilized.
• Finite Element Method (FEM) was used for simulation and analysis, including gain patterns in a skin-tissue model.

Main Results:

• The antenna achieved a resonance frequency of 918 MHz with a 24 MHz bandwidth at -10 dB return loss.
• The antenna's dimensions were limited to a radius of 5 mm and height of 1.64 mm.
• Stable antenna characteristics were observed within the simulated skin-tissue model.

Conclusions:

• The compact, wide-bandwidth, circular antenna is well-suited for DBS implants due to its stable performance in skin.
• The design facilitates wireless power transmission feasibility for implants within the human head.
• This antenna represents a promising solution for enhancing DBS system functionality and reliability.