Thermal impact of an active 3-D microelectrode array implanted in the brain.

Area of Science:

• Biomedical Engineering
• Neuroscience
• Thermal Analysis

Background:

• Chronically implantable wireless neural interfaces require integrated circuits (ICs) to eliminate wired connections.
• Integrated circuits dissipate power, potentially increasing temperature in surrounding brain tissues.
• Understanding thermal effects is crucial for the safety and efficacy of neural implantable devices.

Purpose of the Study:

• To investigate the thermal influence of an integrated 3-D Utah Electrode Array (UEA) device implanted in the brain.
• To validate numerical models with experimental measurements for accurate thermal prediction.
• To analyze factors affecting tissue heating, including power dissipation, blood perfusion, and device geometry.

Main Methods:

• Numerical simulation using finite element analysis (FEA).
• Experimental temperature measurements in vitro and in vivo.
• Validation of numerical models against experimental data.

Main Results:

• Numerically calculated and experimentally measured temperature increases showed good agreement.
• The validated model predicted a linear relationship between temperature increase and power dissipation (0.029 °C/mW).
• Investigated the impact of blood perfusion, brain metabolism, and UEA geometry on tissue heating.

Conclusions:

• The thermal influence of the 3-D Utah Electrode Array (UEA) is predictable and can be accurately modeled.
• The study provides a validated model for assessing temperature increases in brain tissue due to neural implantable devices.
• Findings support the development of safe and effective chronically implantable wireless neural interfaces.