A Novel Pulse Measurement System by Using Laser Triangulation and a CMOS Image Sensor

Area of Science:

• Biomedical Engineering
• Medical Diagnostics
• Optical Measurement

Background:

• Traditional Chinese Medicine (TCM) utilizes pulse diagnosis for health assessment.
• Existing pulse measurement methods can be invasive or lack portability.
• Objective quantification of pulse waveforms is needed for TCM applications.

Purpose of the Study:

• To develop a novel, non-invasive, non-contact system for measuring arterial pulse waveforms.
• To assess the feasibility of using laser triangulation and CMOS imaging for pulse detection.
• To evaluate the system's potential for TCM health prognostics.

Main Methods:

• Utilized a laser diode and a CMOS image sensor for detecting skin surface vibrations.
• Employed laser triangulation and the centroid method combined with Fast Fourier Transform (FFT).
• Measured pulse amplitude and frequency at specific points near the wrist.

Main Results:

• The system successfully detected pulse shape and frequency rapidly.
• Observed significant increases in pulse amplitude and frequency after food intake at the Chun point.
• Achieved a resolution better than 4 μm for arterial pulsation height measurement.
• Reported peak-to-peak amplitudes ranging from 38 to 48 μm and frequencies from 1.27 to 1.35 Hz.

Conclusions:

• A non-contact, portable, and low-cost pulse measurement system using a CMOS image sensor is feasible.
• The developed system is suitable for evaluating and pre-diagnosing human health in TCM clinical practice.
• This technology offers a new avenue for objective pulse diagnosis in TCM.