Method and device for monitoring physiological signal characteristics of a living subject

A sensing device comprising:

• a receiver antenna for receiving a first signal, the first signal comprising a reflected signal of a transmitted signal on a living subject, the transmitted signal being transmitted by a wireless transmitter, the receiver antenna being adapted to be electromagnetically coupled to the transmitter antenna;
• a coupling circuit connected to the receiver antenna for receiving a second signal;
• a self-interference cancellation circuit configured to cancel self-interferences between the first and the second received signals, by attenuating the received first signal;
• an amplifying circuit configured to amplify the received first signal after self-interference cancellation;
• a mixing circuit configured to mix the received second signal and the amplified received first signal a processor configured to monitor physiological signal characteristics of the living subject from the mixed signals;

An apparatus comprising a wireless transmitter adapted to transmit a transmitted signal with a transmitter antenna, the apparatus further comprising a sensing device, the sensing device comprising:

• a receiver antenna for receiving a first signal, the first signal comprising a reflected signal of the transmitted signal on a living subject the transmitted signal being transmitted by a transmitter antenna of a wireless transmitter, the receiver antenna being adapted to be electromagnetically coupled to the transmitter antenna;
• a coupling circuit connected to the receiver antenna for receiving a second signal;
• a self-interference cancellation circuit configured to cancel self-interferences between the first and the second received signals, by attenuating the received first signal
• an amplifying circuit configured to amplify the received first signal after self-interference cancellation;
• a mixing circuit configured to mix the received second signal and the amplified received first signal
• a processor configured to monitor physiological signal characteristics of the living subject from the mixed signals;

A computer-readable storage comprising program code instructions executable by a processor for:

• receiving a first signal from a receiver antenna, the first signal comprising a reflected signal of a transmitted signal on a living subject, the transmitted signal being transmitted by a transmitter antenna of a wireless transmitter, the receiver antenna being adapted to be electromagnetically coupled to the transmitter antenna;
• receiving a second signal from a coupling of the first received signal;
• controlling a self-interference cancellation circuitry for cancelling self-interferences between the first and second received signals prior to amplification;
• monitoring physiological signal characteristics of the living subject from a mixing of the received second signal and the amplified attenuated received first signal.