Self-sensing of temperature rises on light emitting diode based optrodes

Area of Science:

• Biomedical Engineering
• Materials Science
• Optoelectronics

Background:

• Microphotonic devices, such as light-emitting diodes (LEDs), are crucial for implantable applications like opto-electrophysiology and fluorescence sensing.
• Delivering intense light in biological tissues, especially blue wavelengths, presents challenges due to scattering, necessitating local emitters.
• A critical concern with local emitters is heat generation, potentially exceeding the 2°C regulatory limit for probe surfaces, with no current in situ monitoring solutions.

Purpose of the Study:

• To develop a method for accurately determining the surface temperature of microphotonic medical implants.
• To utilize the integrated photonic emitter (LED) as a self-contained temperature sensor.
• To create readout circuitry for precise in situ temperature monitoring of implantable devices.

Main Methods:

• Development of an electronic control circuit specifically designed for monitoring implantable optrode surface temperature.
• Implementation of a calibration method to ensure accurate temperature readings.
• Demonstration of the system's efficacy in various environments, including air, saline, and brain tissue.

Main Results:

• Successful demonstration of a functional electronic control circuit for temperature monitoring.
• Validation of the calibration method for accurate surface temperature assessment.
• Proof of concept showing effective temperature monitoring in diverse biological and non-biological settings.

Conclusions:

• The presented method effectively utilizes the light-emitting diode (LED) as an integrated temperature sensor for implantable devices.
• This self-sensing approach provides a convenient mechanism for in situ temperature monitoring, crucial for safety and efficacy.
• The developed technology addresses a critical gap in monitoring thermal output from microphotonic implants during operation.