Heart rate measurement based on a time-lapse image.

Area of Science:

• Biomedical Engineering
• Physiological Monitoring
• Medical Imaging

Background:

• Accurate and simultaneous measurement of vital signs like respiratory and pulse rates is crucial for patient monitoring.
• Current methods often require physical contact, which can be intrusive or impractical in certain clinical settings.

Purpose of the Study:

• To develop and validate a non-contact, non-invasive device for simultaneous measurement of respiratory and pulse rates.
• To assess the accuracy of the developed device by comparing its measurements with established methods.

Main Methods:

• Utilized a Charge-Coupled Device (CCD) camera to capture time-lapse skin images.
• Analyzed changes in average image brightness within a region of interest (ROI) over 30 seconds.
• Applied signal processing techniques including interpolation, first-order derivative, a 2 Hz low-pass filter, and sixth-order auto-regressive (AR) spectral analysis.

Main Results:

• The AR spectral analysis successfully identified two distinct peaks corresponding to respiratory (approx. 0.3 Hz) and heart rates (approx. 1.2 Hz).
• Achieved high correlation coefficients: 0.90 for heart rate and 0.93 for respiratory rate compared to a pulse oximeter and thermistor.
• Demonstrated the device's capability to measure both vital signs simultaneously and accurately in healthy subjects.

Conclusions:

• The developed non-contact device offers a promising, accurate, and non-invasive method for simultaneous respiratory and pulse rate monitoring.
• This technology has potential applications in various healthcare settings where traditional monitoring methods are challenging.
• Further research could explore its efficacy in diverse patient populations and clinical conditions.