Fiber-optic pulseoximeter for local oxygen saturation determination using a Monte Carlo multi-layer model for...

Area of Science:

• Biomedical Engineering
• Optical Sensing

Background:

• Local tissue oxygenation is vital for physiological and pathological conditions.
• Accurate oxygen measurement is crucial for therapies like photodynamic therapy.
• Photodynamic therapy efficacy relies on sufficient tissue oxygen levels.

Purpose of the Study:

• To design, construct, and calibrate a module for local tissue oxygen saturation measurement.
• To develop a handheld fiber optic-based reflectance pulse oximetry sensor.
• To investigate the sensor's performance under varying skin conditions.

Main Methods:

• Utilized red (660-nm) and infrared (940-nm) LEDs with a photodiode detector.
• Developed a homemade, handheld fiber optic-based reflectance pulse oximetry sensor.
• Employed multilayered Monte Carlo simulations to model sensor behavior in different skin types.

Main Results:

• Generated oxygen saturation calibration curves for various skin thicknesses and melanin concentrations.
• Modeled sensor performance using three-layer and seven-layer skin models.
• Compared the performance of the developed sensor with a commercial pulse oximeter.

Conclusions:

• A novel pulse oximeter for local tissue oxygenation measurement was successfully developed.
• Sensor calibration is site-specific, influenced by tissue thickness, vascularization, and melanin.
• A three-layer skin model is adequate for calibrating the pulse oximeter for thin to medium skin.