[A spectrum extraction method based on uncertainty in noninvasive blood components examinaton]

Area of Science:

• Biomedical Engineering
• Optical Sensing
• Signal Processing

Context:

• Photoplethysmography (PPG) is crucial for noninvasive physiological monitoring.
• Traditional spectrum extraction methods in PPG are susceptible to noise and motion artifacts.
• Accurate extraction of PPG spectra is vital for reliable blood component analysis.

Purpose:

• To introduce an improved spectrum extraction method for PPG signals based on dynamic spectrum theory.
• To reduce the impact of system random error and relative motion artifacts on PPG spectrum extraction.
• To enhance the precision of noninvasive blood component measurements.

Summary:

• A novel spectrum extraction technique utilizing a square-sum-root method is proposed, replacing the conventional peak-peak value method.
• Baseline drift correction is implemented to mitigate motion artifacts between the finger and probe.
• Uncertainty analysis for oxygen saturation coefficient (Q) demonstrates a significant reduction, achieving 38% of the original value compared to the peak-peak method.

Impact:

• The square-sum-root method substantially decreases the uncertainty in oxygen saturation coefficient Q by an average of 58% (42% remaining).
• Experimental validation with ten volunteers confirms the superiority of the proposed method over the peak-peak value method.
• This advancement offers more accurate spectral analysis from PPG, paving the way for improved noninvasive blood component monitoring.