Novel Chest Compression Depth Measurement Sensor Using IR-UWB for Improving Quality of Cardiopulmonary Resuscitation

Cardiac arrest is a common cause of death in the world. Immediate high-quality cardiopulmonary resuscitation (CPR) improves the chances of survival of cardiac arrest patients. In particular, maintaining an adequate chest compression depth (CCD) during CPR is a key determinant for survival from cardiac arrest. If it is possible to measure the CCD accurately during CPR, we could increase the survival rate of patients by improving the quality of CPR. This work proposes a new sensor that could measure the CCD accurately during CPR. Compared with existing sensors that utilize pressures or accelerometers, the proposed sensor employs distance measurements based on the time-difference-of-arrival using impulse-radio ultra-wideband (IR-UWB). The method directly measures the CCD using two antennas at the chest and at the back, thereby eliminating the distance error under CPR environments, which is present in existing accelerometer sensors. The designed sensor has an 0.08 mm resolution, and an inaccuracy of less than ±1.25 mm, within a range of 0-40 cm. This sensor was applied to a CPR manikin to measure the CCD in an environment where CPR is performed.