Design of an oximeter based on LED-LED configuration and FPGA technology

Area of Science:

• Biomedical Engineering
• Optical Sensing Technologies
• Digital Signal Processing

Background:

• Photoplethysmography (PPG) is crucial for non-invasive physiological monitoring.
• Existing PPG sensors face challenges in sensitivity, resolution, and power consumption.
• Accurate blood oxygen saturation (SpO2) measurement is vital for patient care.

Purpose of the Study:

• To develop a fully digital PPG sensor and actuator.
• To enhance PPG signal acquisition and SpO2 determination.
• To create a low-power, high-resolution, and cost-effective sensing solution.

Main Methods:

• A digital PPG sensor and actuator system was designed using Light Emitting Diodes (LEDs) and a Field Programmable Gate Array (FPGA).
• The system employs one LED for light emission and another for detecting reflected light.
• Configurations with two and four LEDs were developed for PPG and SpO2 measurements, with an N-LEDs approach proposed for multichannel SpO2.

Main Results:

• The developed system demonstrated improved spectral sensitivity and adjustable resolution.
• Significant noise reduction was achieved in PPG signal acquisition.
• The digital PPG sensor exhibited small size, low cost, and low power consumption.

Conclusions:

• A fully digital PPG sensor and actuator offers superior performance compared to traditional methods.
• The FPGA-controlled system provides accurate PPG and SpO2 measurements.
• This technology holds promise for advanced, portable, and efficient physiological monitoring.