Using nanosecond pulse near-field sensing technology for non-contact cardiovascular parameters measurement

Clinically arterial stiffness has shown that it is the most important cause of cardiovascular complications and also an independent risk factor to several cardiovascular diseases. In routine, there are many preferable non-invasive methods, including pressure-sensitive transducers, applanation tonometry, Doppler ultrasound and MRI, to get insight of cardiovascular condition. However, the operation of traditional monitors is relied on professionals' experience, and also the sensing probes needed to exert pressure to the user directly. The measurement procedure is short-term and easy to cause discomfort. To improve the issues of these measuring techniques, the non-contact and non-invasive measuring method will become an important innovation. In this paper, the novel nanosecond pulse near-field sensing (NPNS) based screening technology, which includes radio frequency (RF) pulse transmission and a flat antenna connected to transceiver of miniature radar, is proposed to monitor cardiovascular activity. A dedicated analysis software is also provided to calculate cardiovascular parameters, including PWV, average systolic time, reflection index (RI), heart and heart rate variability (HRV), for clinical applications. To evaluate the performance, the proposed method was applied on aortic pulse measurement at the body site of chest. As a result, it shows 0.92 correlations with the measurement result from commercial product, and performs the capability of continuously long-term monitoring in real-time.