# US 2018/0323504 A1 · Method and device for monitoring physiological signal characteristics of a living subject > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323504 A1 - Document ID: US20180323504A1 - Status: Published application - Kind: A1 - Application number: 15/967,999 - Filed: 2018-05-01 - Published: 2018-11-08 - Earliest claimed: 2017-05-02 - Assignees: Thomson Licensing - Applicants: THOMSON Licensing - Inventors: Ali LOUZIR; Rupesh KUMAR; JEAN YVES LE NAOUR - Web page: https://patentgrep.com/patent/US20180323504A1 ## CPC - H01Q 1/525: {between emitting and receiving antennas} - A61B 5/0006: {ECG or EEG signals} - A61B 5/0015: {characterised by features of the telemetry system} - A61B 5/0205: Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition - A61B 5/024: Measuring pulse rate or heart rate - A61B 5/05: Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves (measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24) - A61B 5/0507: using microwaves or terahertz waves - A61B 5/0816: {Measuring devices for examining respiratory frequency (measuring frequency of electric signals G01R23/00)} - A61B 5/113: occurring during breathing - A61B 5/7203: {for noise prevention, reduction or removal} - A61B 5/7214: {using signal cancellation, e.g. based on input of two identical physiological sensors spaced apart, or based on two signals derived from the same sensor, for different optical wavelengths} - A61B 5/7225: {Details of analogue processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation (input circuits for detecting, measuring, or recording bioelectric or biomagnetic signals A61B5/30; specific diagnostic methods using bioelectric or biomagnetic signals A61B5/316)} - A61B 5/7278: {Artificial waveform generation or derivation, e.g. synthesizing signals from measured signals} - H04B 1/10: Means associated with receiver for limiting or suppressing noise or interference - A61B 5/4818: {Sleep apnoea} - A61B 2562/0228: Microwave sensors - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - H04B: TRANSMISSION ## Abstract A method for monitoring physiological signal characteristics of a living subject is disclosed. A salient idea is to electromagnetically couple the antennas of respectively a networking device and a monitoring device, the networking device transmitting a wireless signal, the monitoring device receiving first and second signals from the electromagnetic coupling. The first and second signals include a reflection of the transmitted signal on a living subject as well as a part of the transmitted signal resulting from the antenna coupling. A self-interference cancellation processing is applied to the received first and second signals for extracting the reflected signal from the first signal prior to amplifying and mixing with the received second signal to monitor physiological signal characteristics of the living subject. ## Claims ### Claim 1 A method for monitoring physiological signal characteristics of a living subject, the method comprising: receiving a first signal in a sensing module, the first signal comprising a reflected signal of a transmitted signal on the living subject, the transmitted signal being transmitted by a wireless transmitter; receiving a second signal in the sensing module coupled to the wireless transmitter; amplifying the received first signal; mixing the received second signal and the amplified received first signal to monitor the physiological signal characteristics wherein a receiver antenna of the sensing module is electromagnetically coupled to a transmitter antenna of the wireless transmitter; a self-interference cancellation is applied to the received first and second signals before amplifying and mixing. ### Claim 2 (depends on 1) The method according to claim 1, wherein the received second signal is obtained from a RF coupler connected to the receiver antenna of the sensing module. ### Claim 3 (depends on 1) The method according to claim 1, wherein applying a self-interference cancellation comprises applying a variable gain amplifier and a variable phase shifter to the received second signal, the variable gain amplifier operating with amplitude saturation, the variable gain amplifier and the variable phase shifter being configured to extract the reflected signal from the received first signal. ### Claim 4 (depends on 1) The method according to claim 1, wherein applying a self-interference cancellation comprises limiting the received second signal for removing the reflected signal and applying a variable gain amplifier and a variable phase shifter to the received limited second signal, the variable gain amplifier and the variable phase shifter being configured to extract the reflected signal from the received first signal. ### Claim 5 (depends on 1) The method according to claim 1, wherein the variable gain amplifier and the variable phase shifter are statically configured. ### Claim 6 (depends on 1) The method according to claim 1, wherein the variable gain amplifier and the variable phase shifter are dynamically controlled. ### Claim 7 (depends on 1) The method according to claim 1, wherein the wireless transmitter is a Wi-Fi access point. ### Claim 8 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; ### Claim 9 (depends on 8) The sensing device according to claim 8, wherein the self-interference cancellation circuit comprise a variable gain amplifier and a variable phase shifter, the variable gain amplifier operating with amplitude saturation, the variable gain amplifier and the variable phase shifter being configured to extract the reflected signal from the received first signal. ### Claim 10 (depends on 9) The sensing device according to claim 9, wherein the variable gain amplifier and the variable phase shifter are dynamically controlled. ### Claim 11 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; ### Claim 12 (depends on 11) The apparatus according to claim 11, wherein the self-interference cancellation circuit comprises a variable gain amplifier and a variable phase shifter, the variable gain amplifier operating with amplitude saturation, the variable gain amplifier and the variable phase shifter being configured to extract the reflected signal from the received first signal. ### Claim 13 (depends on 12) The apparatus according to claim 12, wherein the variable gain amplifier and the variable phase shifter are statically configured. ### Claim 14 (depends on 12) The apparatus according to claim 12, wherein the variable gain amplifier and a variable phase shifter are dynamically controlled. ### Claim 15 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.