Fig 1.
Chest compression depth measurement using impulse-radio ultra-wideband sensor.
Tx: transmitter; Tx Ant.: transmitter antenna; Rx Ant.: receiver antenna; Δd: chest compression depth; Δt: the time difference between the received signal before chest compression and that according to the location of the receiver which changes in real time during chest compressions.
Fig 2.
Patch antenna printed circuit board (22 cm × 10 cm).
Fig 3.
Transmitter system-on-chip printed circuit board (5 cm × 3 cm).
White arrow: transmitter system-on-chip designed in 65nm CMOS process (1 mm × 0.4 mm).
Fig 4.
Measured chest compression depths on different surfaces with the CPRmeter (gray bar) and IR-UWB sensor (white bar).
The black bars represent the depths measured by the Resusci Anne QCPR. The bars display the means, and the error bars indicate ± SD. * p<0.001 Resusci Anne QCPR vs. CPRmeter on all surfaces and Resusci Anne QCPR vs. IR-UWB sensor on the floor; † p = 0.012 Resusci Anne QCPR vs. IR-UWB sensor on the foam mattress.