RANGE GATED RADIO FREQUENCY PHYSIOLOGY SENSOR

• US 20140024917A1
• Filed: 07/18/2013
• Published: 01/23/2014
• Est. Priority Date: 07/20/2012
• Status: Active Grant

• Current Assignee: ResMed Sensor Technologies Limited (ResMed Incorporated)
• Original Assignee: ResMed Sensor Technologies Limited (ResMed Incorporated)
• Inventors: Wren, Michael, Heneghan, Conor, McMahon, Stephen, Wood, Spencer Terry, Conway, Kieran
• Granted Patent: US 9,445,729 B2
• Time in Patent Office: Days
• US Class Current: 600/407
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/1102 Ballistocardiography
• CPC Class Codes: A61B 5/1126 using a particular sensing technique
• CPC Class Codes: A61B 5/4809 Sleep detection, i.e. determining whether a subject is asleep or not
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: G01S 13/18 wherein range gates are used
• CPC Class Codes: G01S 13/56 for presence detection presence detection using near field arrangements G01V3/00, e.g. G01V3/08, G01V3/12; burglar, theft or intruder alarms with electrical actuation G08B13/22 - G08B13/26
• CPC Class Codes: G01S 7/282 Transmitters
• CPC Class Codes: H03B 5/187 the active element in the amplifier being a semiconductor device

Abstract

A sensor for physiology sensing may be configured to generate oscillation signals for emitting radio frequency pulses for range gated sensing. The sensor may include a radio frequency transmitter configured to emit the pulses and a receiver configured to receive reflected ones of the emitted radio frequency pulses. The received pulses may be processed to detect physiology characteristics such as motion, sleep, respiration and/or heartbeat. In some embodiments, the sensor may employ a circuit including a pulse generator configured to generate signal pulses. The circuit may also include a dielectric resonator oscillator configured to generate a radio frequency oscillating signal. A switched oscillation circuit may be coupled to the pulse generator and the dielectric resonator oscillator. The switched circuit may be configured to generate a pulsed radio frequency oscillating signal for emitting the radio frequency pulses.

Claims

1. A radio frequency motion sensor comprising:

a radio frequency transmitter, the transmitter configured to emit radio frequency pulses; and

a receiver configured to receive reflected ones of the emitted radio frequency pulses,

the radio frequency transmitter comprising;

a pulse generator configured to generate signal pulses;

a dielectric resonator oscillator configured to generate a stable radio frequency oscillating signal; and

a switched circuit coupled to the pulse generator and the dielectric oscillator, the switch circuit configured to generate a pulsed radio frequency oscillating signal whose dominant frequency is derived from the dielectric resonator oscillator.

2. The sensor of claim 1 wherein the dielectric resonator oscillator comprises a dielectric resonator and a transistor.

3. The sensor of claim 2 wherein the switched circuit comprises a transistor having a drain, a gate and a source, and wherein the dielectric resonator is coupled to the gate and drain of the transistor.

4. The sensor of claim 1 or claim 2 wherein the switched circuit comprises a switchable radio-frequency amplifier.

5. The sensor of claim 4 wherein the amplifier comprises a transistor having a drain, a gate and a source, the amplifier configured to amplify the radio frequency oscillating signal synchronously with the pulse signal to generate the pulsed radio frequency oscillating signal.

6. The sensor of claim 5 wherein the drain is coupled to receive the signal pulses from the pulse generator.

7. The sensor of claim 5 or claim 6 wherein the gate of the amplifier transistor is coupled to receive the radio frequency oscillating signal from the dielectric resonator oscillator.

8. The sensor of claim 1 or claim 2 wherein the switched circuit comprises a wideband oscillator, the wideband oscillator configured to injection lock with the dielectric resonator oscillator.

9. The sensor of claim 8 wherein the wideband oscillator comprises a transistor having a drain, a gate and a source, the wideband oscillator including a feedback network circuit coupled to the drain.

10. The sensor of any of the preceding claims further comprising an attenuator and matching network circuit between an output of the dielectric resonator oscillator and an input of the switched circuit.

11. The sensor of claim 10 wherein the matching network circuit comprises a microstrip feed line coupled with a gate of a transistor of the switched circuit.

12. The sensor of claim 11 wherein the microstrip feed line is in a direct feed configuration.

13. The sensor of claim 11 wherein the microstrip feed line is in an indirect feed configuration.

14. The sensor of any of the preceding claims wherein the pulse generator comprises a logic gate circuit.

15. The sensor of claim 14 wherein the logic gate comprises a NAND gate.

16. The sensor of claim 14 or claim 15 wherein an output of the logic gate is coupled with a gate of a transistor of the switched circuit.

17. The sensor of any of the preceding claims further comprising a processor, the processor configured for processing the received reflected ones of the emitted radio frequency pulses to derive an indicator of any one or more of respiration, sleep and heart rate.

18. The sensor of claim 17 further comprising a respiratory treatment apparatus, the respiratory treatment apparatus including a flow generator with a processor, the processor of the respiratory treatment apparatus being configured to process the indicator.

19. A circuit for generating signals to produce radio frequency pulses for range gated physiology sensing, the circuit comprising:

a pulse generator configured to generate signal pulses;

a dielectric resonator oscillator configured to generate a radio frequency oscillating signal;

a switched amplifier circuit coupled to the pulse generator and the dielectric resonator oscillator, the switched amplifier circuit configured to generate a pulsed radio frequency oscillating signal in accordance with the signal pulses and radio frequency oscillating signal; and

an antenna feed coupled with an output of the switched amplifier circuit to accept the pulsed radio frequency oscillating signal and emit radio frequency pulses in accordance with the pulsed radio frequency oscillating signal via an antenna.

20. The circuit of claim 19 wherein the dielectric resonator oscillator comprises a dielectric resonator and a transistor.

21. The circuit of claim 20 wherein the transistor has a drain, a gate and a source, and wherein the dielectric resonator is coupled to the gate and to the drain of the transistor.

22. The circuit of claim 20 or 21 wherein the amplifier comprises a transistor having a drain, a gate and a source, the amplifier configured to amplify the radio frequency oscillating signal synchronously with the pulse signal to generate the pulsed radio frequency oscillating signal.

23. The circuit of claim 22 wherein the drain of the amplifier transistor is coupled to receive the signal pulses from the pulse generator.

24. The circuit of claim 22 or claim 23 wherein the gate of the amplifier transistor is coupled to receive the radio frequency oscillating signal from the dielectric resonator oscillator.

25. The circuit of any one of claims 20 to 24 further comprising a filter and a set of magnitude detectors coupled with the antenna feed, wherein the magnitude detectors detect signals received with the antenna feed based on signals generated from the switched amplifier circuit.

26. A circuit for generating signals to produce radio frequency pulses for range gated physiology sensing, the circuit comprising:

a pulse generator configured to generate signal pulses;

a dielectric resonator oscillator configured to generate a radio frequency oscillating signal;

a switched oscillator circuit coupled to the pulse generator and the dielectric oscillator, the switch oscillator circuit configured to generate a pulsed radio frequency oscillating signal in accordance with the signal pulses and radio frequency oscillating signal; and

an antenna feed coupled with an output of the switched oscillator circuit to accept the pulsed radio frequency oscillating signal and to emit radio frequency pulses in accordance with the pulsed radio frequency oscillating signal via an antenna.

27. The circuit of claim 26 wherein the dielectric resonator oscillator comprises a dielectric resonator and a transistor.

28. The circuit of claim 27 wherein the transistor has a drain, a gate and a source, and wherein the dielectric resonator is coupled to the gate and to the drain of the transistor.

29. The circuit of any one of claims 26 to 28 wherein the switched oscillator circuit comprises a wideband oscillator, the wideband oscillator configured to injection lock with the dielectric resonator oscillator.

30. The circuit of any one of claims 26 to 29 wherein the switched oscillator circuit comprises a transistor having a drain, a gate and a source, the switched oscillator circuit including a feedback network coupled to the drain.

31. The circuit of claim 30 wherein an attenuator and matching network couples the radio frequency oscillating signal output of the dielectric resonator oscillator with the gate of the transistor of the switched oscillator circuit by a microstrip feed line coupled to the gate of the transistor of the switched oscillation circuit.

32. The circuit of claim 31 wherein the microstrip feed line is in a direct configuration.

33. The circuit of claim 31 wherein the microstrip feed line is in an indirect configuration.

34. The circuit of any one of claims 26 to 33 wherein the pulse generator is coupled with a gate of a transistor of the switched oscillator circuit.