Direct frequency modulating radio-frequency sensors

• US 10,238,288 B2
• Filed: 06/15/2017
• Issued: 03/26/2019
• Est. Priority Date: 06/15/2017
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Gupta, Sidhant, Lester, Jonathan, Ranganathan, Vaishnavi Nattar
• Primary Examiner(s): Singh, Hirdepal
• Application Number:
  US15/624,584
• Publication Number:
  US 20180360312A1
• Time in Patent Office: 649 Days
• Field of Search: 34087018
• CPC Class Codes: A61B 2560/0204 of power management
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0024 for multiple sensor units attached to the patient, e.g. using a body or personal area network
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/4806 Sleep evaluation A61B5/4821 takes precedence; devices for inducing sleep A61M21/02
• CPC Class Codes: A61B 5/6801 specially adapted to be attached to or worn on the body surface
• CPC Class Codes: A61B 5/6813 Specially adapted to be attached to a specific body part A61B5/6802 takes precedence
• CPC Class Codes: A61B 5/6832 using adhesives A61B5/259 takes precedence
• CPC Class Codes: A61B 5/7228 Signal modulation applied to the input signal sent to patient or subject; demodulation to recover the physiological signal modulation H03C
• CPC Class Codes: H04Q 2209/40 using a wireless architecture
• CPC Class Codes: H04Q 2209/886 using energy harvesting, e.g. solar, wind or mechanical
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A wearable radio frequency receiver device is provided, which includes a receiver antenna configured to receive an interrogation signal from a transmitter. The receiver device further includes a sensor coupled to the receiver antenna and configured to receive a physiological input from a user wearing the device and generate a sensor signal based on the physiological input, and a modulator configured to perform direct modulation on the received interrogation signal based on the sensor signal to encode the physiological input in the directly modulated interrogation signal. The receiver antenna may be configured to reflect at least a portion of the directly modulated interrogation signal as backscatter radiation. A transceiver including a transceiver antenna may be provided to receive the directly modulated interrogation signal, and the modulation receiver may be configured to process the directly modulated interrogation signal and output a decoded physiological input.

Claims

1. A wearable radio frequency receiver device, comprising:

a receiver radio antenna configured to receive an interrogation signal from a transmitter;

a sensor coupled to the receiver radio antenna and configured to receive a physiological input from a user wearing the device and generate an analog sensor signal based on the physiological input; and

a modulator configured to perform direct frequency modulation on the received interrogation signal based on the analog sensor signal so as to generate a directly frequency modulated interrogation signal carrying an analog response, wherein

the receiver radio antenna is configured to emit at least a portion of the directly frequency modulated interrogation signal as reflected backscatter radiation carrying the analog response.

2. The device of claim 1, wherein

the modulation is frequency modulation that is accomplished by frequency-shift keying.

3. The device of claim 1, further comprising:

an adhesive pad configured to adhere to a skin of the user, wherein

the receiver radio antenna is configured to be embedded within the adhesive pad.

4. The device of claim 1, further comprising:

a backscatter modulation switch configured to switch the receiver in one of two configurations;

an open configuration and a short configuration.

5. The device of claim 4, wherein

the backscatter modulation switch is one of a JFET and a MOSFET.

6. The device of claim 1, wherein

the modulator is a voltage-controlled or current-controlled oscillator configured to control an oscillation frequency of the received interrogation signal based upon the sensor signal.

7. The device of claim 1, wherein

the sensor is one of a variable impedance sensor, variable capacitance sensor, variable voltage sensor, variable resistance sensor or variable current sensor.

8. The device of claim 1, further comprising:

a power harvester and/or a charge storage operatively coupled to the sensor and configured to harvest electrical power from the interrogation signal and at least temporarily store the electrical power, to thereby provide electrical power to the sensor.

9. The device of claim 8, wherein

the power harvester includes a capacitor;

and/or

the charge storage includes a battery and/or a capacitor.

10. The device of claim 1, further comprising:

a receiver front end configured to receive the interrogation signal from the antenna and electrically process the interrogation signal, the receiver front end comprising at least one of a band-pass filter, a radiofrequency amplifier, a local oscillator, and/or a mixer.

11. A sensor system, comprising:

a transceiver including a transceiver processor configured to execute a modulation receiver, and a transceiver antenna configured to transmit an interrogation signal generated by the modulation receiver; and

a wearable radio frequency receiver device including a receiver radio antenna configured to receive the interrogation signal from the transceiver antenna, a sensor coupled to the receiver radio antenna and configured to receive a physiological input from a user wearing the device and generate an analog sensor signal based on the physiological input, and a modulator configured to perform direct frequency modulation on the received interrogation signal based on the analog sensor signal so as to generate a directly frequency modulated interrogation signal carrying an analog response, to encode the physiological input in the directly frequency modulated interrogation signal, wherein the receiver radio antenna is configured to emit at least a portion of the directly frequency modulated interrogation signal as reflected backscatter radiation carrying the analog response, wherein

the transceiver antenna is configured to receive the directly frequency modulated interrogation signal, and the modulation receiver is configured to process the directly frequency modulated interrogation signal and output a decoded physiological input.

12. The system of claim 11, wherein

the modulation is frequency modulation that is accomplished by frequency-shift keying.

13. The system of claim 11, wherein

the receiver device further comprises a flexible substrate, and the receiver radio antenna, sensor, and modulator are coupled to the flexible substrate.

14. The system of claim 13, wherein the flexible substrate includes an adhesive layer configured to releasably adhere to the skin or clothes of the user.

15. The system of claim 11, further comprising:

a backscatter modulation switch configured to switch the receiver in one of two configurations;

an open configuration and a short configuration, wherein

the backscatter modulation switch is one of a JFET and a MOSFET.

16. The system of claim 11, wherein

the modulator is a voltage-controlled or current-controlled oscillator configured to control an oscillation frequency of the received interrogation signal based upon the sensor signal.

17. The system of claim 11, wherein

the sensor is one of a variable impedance sensor, variable capacitance sensor, variable voltage sensor, variable resistance sensor or variable current sensor.

18. A sensor system comprising:

a transceiver including a transceiver processor and a transceiver antenna configured to transmit an interrogation signal generated by the processor; and

a wearable radio frequency receiver device including a receiver radio antenna configured to receive the interrogation signal from the transceiver antenna, a sensor coupled to the receiver radio antenna and configured to receive a physiological input from a user wearing the device and generate an analog sensor signal based on the physiological input, and a modulator configured to perform direct frequency modulation on the received interrogation signal based on the analog sensor signal so as to generate a directly frequency modulated interrogation signal carrying an analog response, to encode the physiological input in the directly frequency modulated interrogation signal, wherein the receiver radio antenna is configured to emit at least a portion of the directly frequency modulated interrogation signal as reflected backscatter radiation carrying the analog response, wherein

the transceiver antenna is configured to receive the directly frequency modulated interrogation signal, and the processor is configured to process the directly frequency modulated interrogation signal and output a decoded physiological input.