Waveform Morphology Comparison in Wearable Blood Pressure Sensors.

Wearable devices for continuous non-invasive blood pressure monitoring must be capable of providing a continuous waveform representative of arterial blood pressure. This paper establishes the distinctions in waveform morphology between wearable sensor modalities, specifically millimeter-wave radar and photoplethysmography, when compared to a reference continuous non-invasive blood pressure monitor. An analysis of a 115-subject dataset was conducted to assess waveform suitability. Millimeter-wave radar waveform morphology was found to more closely resemble continuous non-invasive blood pressure than photoplethysmography. Clinical Relevance- This paper compares the waveform morphology and content of signals from wearable sensors in the context of continuous non-invasive blood pressure monitoring.

Wearable Millimeter-Wave Device for Contactless Measurement of Arterial Pulses.

Wearable monitors for measuring vital signs such as blood pressure will greatly impact the medical field. This work presents a millimeter-wave, radar-based system for performing accurate measurements of arterial pulse waveforms without contacting the region that is pulsing. Electromagnetic and radar-system simulation models are utilized to demonstrate the viability and safety of this approach. This is followed by hardware/software implementation and a study on 12 human subjects. Measured radial arterial waveforms exhibit signal strengths that are well above the noise floor of the system and a morphology that would be expected in an arterial pulse. Finally, comparison of the radar-based signals with a reference tonometer indicates a strong correlation between waveforms, as well as similar spectral signatures. The results observed suggest a millimeter-wave based approach for arterial pulse detection is very promising for future applications in pulse wave analysis and pulse transit time measurement for blood pressure tracking.