Figure 1.

Acquisition and processing of the IR-UWB radar signals from the heart. (A) The experiment was conducted with participants whose clothes were on after 5–10 minutes’ rest. To measure the heart signals only, the participants were told to hold their breath for 20 seconds. During the breath-holding, the IR-UWB radar and ECG were measured simultaneously. (B) The IR-UWB radar system transmitted radiofrequency pulse waves and received signals reflected from an object. Analogue signals received from the object were digitalized by an ADC chip embedded in the radar device. The digital data obtained from the radar were sent to MATLAB for further processing. (C) The raw signals passed through a bandpass filter to cancel noise, then were processed to separate clutter signals from target signals. By tracing the target signals during breath-holding, the heart signals were obtained.