Range gated radio frequency physiology sensor

• US 10,143,386 B2
• Filed: 07/19/2013
• Issued: 12/04/2018
• 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: McMahon, Stephen, Wren, Michael, Wood, Spencer Terry, Conway, Kieran, Heneghan, Conor
• Primary Examiner(s): Layno, Carl H
• Assistant Examiner(s): Morales, Jon Eric C
• Application Number:
  US14/415,677
• Publication Number:
  US 20150216424A1
• Time in Patent Office: 1,964 Days
• Field of Search: 600301, 607 32, 607 60
• 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 402 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, wherein the pulse generator comprises a logic gate circuit;

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 resonator oscillator, the switched circuit configured to generate a pulsed radio frequency oscillating signal that is modulated by the signal pulses of the pulse generator and 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 1 wherein the switched circuit comprises a switchable radio-frequency amplifier.

4. The sensor of claim 3 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 signal pulses to generate the pulsed radio frequency oscillating signal.

5. The sensor of claim 4 wherein the drain is coupled to receive the signal pulses from the pulse generator.

6. The sensor of claim 4 wherein the gate of the amplifier'"'"'s transistor is coupled to receive the radio frequency oscillating signal from the dielectric resonator oscillator.

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

8. The sensor of claim 7 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.

9. The sensor of claim 1 further comprising an attenuator and matching network circuit between an output of the dielectric resonator oscillator and an input of the switched circuit.

10. The sensor of claim 9 wherein the matching network circuit comprises a microstrip feed line coupled with a gate of a transistor of the switched circuit.

11. The sensor of claim 10 wherein the microstrip feed line is in a direct feed configuration.

12. The sensor of claim 10 wherein the microstrip feed line is in an indirect feed configuration.

13. The sensor of claim 1 wherein the logic gate circuit comprises a NAND gate.

14. The sensor of claim 1 wherein an output of the logic gate of the logic gate circuit is coupled with a gate of a transistor of the switched circuit.

15. The sensor of claim 1 in which an onset time of the signal pulses is varied with respect to overall signal pulse generation timing.

16. The sensor of claim 1 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 body movement, respiration, sleep and heart rate.

17. The sensor of claim 16 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.

18. The sensor of claim 1 wherein the radio frequency transmitter further comprises a dithering circuit, the dithering circuit coupled with the pulse generator to dither signal pulses generated by the pulse generator.

19. The sensor of claim 18 wherein the dithering circuit comprises a synchronous ramp dithering circuit.

20. 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, wherein the pulse generator comprises a logic gate circuit;

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;

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

a dithering circuit coupled with the pulse generator to dither the signal pulses generated by the pulse generator.

21. The circuit of claim 20 wherein the dithering circuit comprises a synchronous ramp dithering circuit.

22. 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, wherein the pulse generator comprises a logic gate circuit;

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

a switched circuit coupled to the pulse generator and the dielectric resonator oscillator, the switched 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 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.

23. The circuit of claim 22 wherein the dielectric resonator oscillator comprises a dielectric resonator and a transistor.

24. The circuit of claim 23 wherein the transistor has a drain, a gate and a source, and wherein the dielectric resonator oscillator is coupled to the gate and to the drain of the transistor.

25. The circuit of claim 22 wherein the switched circuit comprises a switched wideband oscillator, the wideband oscillator configured to injection lock with the dielectric resonator oscillator.

26. The circuit of claim 22 wherein the switched circuit comprises a transistor having a drain, a gate and a source, the switched circuit including a feedback network coupled to the drain.

27. The circuit of claim 26 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 circuit by a microstrip feed line coupled to the gate of the transistor of the switched circuit.

28. The circuit of claim 27 wherein the microstrip feed line is in a direct configuration.

29. The circuit of claim 27 wherein the microstrip feed line is in an indirect configuration.

30. The circuit of claim 22 wherein the pulse generator is coupled with a gate of a transistor of the switched circuit.

31. The circuit of claim 22 further comprising a dithering circuit, the dithering circuit coupled with the pulse generator to dither signal pulses generated by the pulse generator.

32. The circuit of claim 31 wherein the dithering circuit comprises a synchronous ramp dithering circuit.