Comparative measurement of cardiac cycle by means of different sensors

Ultra wideband (UWB) signals for medical diagnostics have been in research focus for decades. UWB medical radar is promising technology for breast cancer detection, brain hematoma diagnosis and vital sign monitoring. It is contactless and emits only low-power non-ionizing radiation. One of the promising applications is cardiac monitoring. While the cardiac cycles can be clearly seen in the UWB radar response, the propagation path of the vital biological information into the radar signal is still debatable. Commonly three major physiological effects are considered as a source of the signal - blood perfusion of the skin, skin movement and echoes from heart wall. Multisensory approach is introduced to assess the impact of the different contributors. ballistocardiographic, phonocardiographyc and optical reflection signals are recorded from the surface of the skin on chest, together with reference electrocardiography signal between two hands. Custom built UWB cardiograph was used. Recorded signals were analysed, and the results suggest that the proposed approach is viable for making assessments for the origin of the cardiac component in the UWB radar signal. Results are in agreement with findings in recent publications on the topic, where different approach was utilized.