Detection of cardiac activity using a 5.8 GHz radio frequency sensor

Area of Science:

• Biomedical Engineering
• Medical Devices
• Signal Processing

Background:

• Non-contact monitoring of physiological signals is crucial for patient care.
• Existing methods may be invasive or limited in application.
• Radio-frequency (RF) sensing offers a promising non-contact approach.

Purpose of the Study:

• To evaluate the accuracy of a 5.8-GHz ISM-Band RF sensor for non-contact heart rate measurement.
• To compare two algorithmic approaches (peak detection and spectral analysis) for heart rate extraction.
• To assess the sensor's utility for chronic disease monitoring.

Main Methods:

• Simultaneous recordings using the RF sensor and a reference pulse oximeter.
• Data collected from ten healthy subjects over 15-minute periods.
• Two algorithms applied: automated peak detection and 60-second spectral analysis.

Main Results:

• Spectral analysis algorithms achieved heart rate measurements within +/-10% accuracy.
• Peak detection methods showed lower accuracy but potential for beat-by-beat data.
• Both algorithms were compared against manually extracted peaks and pulse oximeter data.

Conclusions:

• The 5.8-GHz RF sensor, particularly with spectral analysis, provides accurate non-contact heart rate measurements.
• This technology is suitable for stationary and semi-stationary subjects at distances of 0.5-1.5 meters.
• Non-contact heart rate monitoring can benefit chronic disease management, including heart failure and cardiovascular disease.