ULTRA WIDEBAND MONITORING SYSTEMS AND ANTENNAS

• US 20090227882A1
• Filed: 03/06/2007
• Published: 09/10/2009
• Est. Priority Date: 03/06/2006
• Status: Active Grant

• Current Assignee: Keenly Health LLC
• Original Assignee: Sensiotec, Inc.
• Inventors: Foo, Senglee
• Granted Patent: US 8,428,696 B2
• Time in Patent Office: Days
• US Class Current: 600/508
• CPC Class Codes: A61B 2562/0228 Microwave sensors
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 2562/166 the sensor is mounted on a specially adapted printed circuit board
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• 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 5/02444 Details of sensor A61B5/02427 takes precedence
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; 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
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/103 Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes A61B5/08 takes precedence; measuring aids for tailors A41H1/00; measuring instruments specially adapted for dentistry A61C19/04
• CPC Class Codes: A61B 5/1113 Local tracking of patients, e.g. in a hospital or private home
• CPC Class Codes: A61B 5/1115 Monitoring leaving of a patient support, e.g. a bed or a wheelchair
• CPC Class Codes: A61B 5/1117 Fall detection
• CPC Class Codes: A61B 5/6891 Furniture
• CPC Class Codes: A61B 5/6892 Mats
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• 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 13/886 : for alarm systems alarms with electrical actuation G08B13/22
• CPC Class Codes: G01S 7/003 : Transmission of data between radar, sonar or lidar systems and remote stations
• CPC Class Codes: H01Q 21/0075 : Stripline fed arrays H01Q21/065 takes precedence
• CPC Class Codes: H01Q 21/062 : using dipole aerials; H01Q21/067, H01Q21/068 take precedence
• CPC Class Codes: H01Q 9/285 : Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407
• CPC Class Codes: Y10S 128/903 : Radio telemetry

Abstract

Apparatus for monitoring vital signs of one or more living subjects comprises a monitoring station and at least one sensor in communication with the monitoring station. The sensor comprises an antenna system, an ultra wideband radar system coupled to the antenna system, a signal processor and a communication system. The signal processor is connected to receive a signal from the ultra wideband radar system and configured to extract from the signal information about one or more vital signs of a person or animal in a sensing volume corresponding to the antenna system. The communication system is configured to transmit the information to the monitoring station.

Claims

1. Apparatus for monitoring vital signs of one or more living subjects, the apparatus comprising:

a monitoring station;

at least one sensor in communication with the monitoring station, the sensor comprising;

an antenna system;

an ultra wideband radar system coupled to the antenna system;

a signal processor connected to receive a signal from the ultra wideband radar system and configured to extract from the signal information about one or more vital signs of a person or animal in a sensing volume corresponding to the antenna system; and

a communication system configured to transmit the information to the monitoring station.

2. Apparatus according to claim 1 comprising a mattress wherein the antenna system is located below an upper surface of the mattress.

3. Apparatus according to claim 1 comprising a mattress wherein the antenna system is located under the mattress.

4. Apparatus according to claim 3 wherein the antenna system is covered by a radome that is substantially transparent to ultra wideband radiation wherein the radome is located under the mattress.

5. Apparatus according to claim 4 comprising a metallic mounting surface underlying the antenna system wherein the antenna system is spaced apart from the mounting surface by an air gap.

6. Apparatus according to claim 2 wherein the antenna system comprises an array of antennas extending across the mattress in a band at a location between head and foot ends of the mattress.

7. Apparatus according to claim 1 wherein:

the antenna system comprises a plurality of groups of antennas,

a group of antennas comprising at least one transmit antenna connected to transmit ultra wideband pulses generated by the ultra wideband radar system and a plurality of receive antennas connected to receive ultra wideband pulses reflected by the person or animal;

wherein the plurality of receive antennas are approximately equally spaced from the transmit antenna.

8. Apparatus according to claim 7 wherein the transmit antenna and the plurality of receive antennas are disposed on a substantially planar substrate.

9. Apparatus according to claim 1 wherein the antenna system comprises at least one transmit antenna connected to transmit ultra wideband pulses generated by the ultra wideband radar system and a receive antenna connected to receive ultra wideband pulses reflected by the person or animal.

10. Apparatus according to claim 9 wherein the transmit antenna has a lower gain than the receive antenna.

11. Apparatus according to claim 1 wherein the antenna system comprises an array of antennas disposed on a substantially planar member.

12. Apparatus according to claim 1 wherein the antenna system comprises an array of receive antennas and at least one transmit antenna disposed on a substantially planar member.

13. Apparatus according to claim 1 wherein the radar system comprises a transmitter configured to generate pulses having durations of 3 ns or less and a receiver gated by pulses having lengths in excess of 5 ns.

14. Apparatus according to claim 1 wherein the signal processor comprises a data processor executing instructions that cause the data processor to transform the signal into the frequency domain and to identify a peak in the transformed signal lying within a band of frequencies characteristic of heart rates.

15. Apparatus according to claim 14 wherein the instructions cause the data processor to search for a peak in a frequency range that is based at least in part upon a previously-determined heart rate.

16. Apparatus according to claim 14 wherein, if the data processor identifies a plurality of peaks in the band of frequencies, the instructions cause the data processor to select one of the plurality of peaks that is closest to a previously-determined heart rate.

17. Apparatus according to claim 1 wherein the signal processor comprises a data processor executing instructions that cause the data processor to transform the signal into the frequency domain and to identify a peak lying within a band of frequencies characteristic of breathing rates.

18. Apparatus according claim 14 wherein the data processor is configured to detect in the signal motion artifacts and to generate a motion-sensed signal indicating that the person or animal is moving.

19. Apparatus according to claim 18 wherein the monitoring station is configured to temporarily suppress display of updated information regarding a vital sign in response to the motion-sensed signal.

20. Apparatus according to claim 1 wherein the radar system comprises a reflected power output and the signal processor is configured to monitor a reflected power signal at the reflected power output and to generate an occupancy signal based at least in part upon the reflected power signal.

21. Apparatus according to claim 20 comprising an amplifier and a low-pass filter wherein the reflected power signal is a signal that has been amplified by the amplifier and filtered by the low-pass filter.

22. Apparatus according to claim 1 wherein the radar system comprises first and second reflected power outputs that carry first and second reflected power signals and the signal processor is configured to monitor a difference between the first and second reflected power signals and to generate an occupancy signal based at least in part upon the difference.

23. Apparatus according to claim 1 wherein the antenna system comprises at least one antenna that comprises a first element on a first side of a generally planar substrate and a second element on a second side of the substrate opposed to the first side, wherein each of the first and second elements are symmetrical about a centre line.

24. Apparatus according to claim 23 wherein each of the elements comprises a plurality of stubs.

25. Apparatus according to claim 24 wherein the stubs are pointed.

26. Apparatus according to claim 24 wherein the stubs are of different lengths.

27. Apparatus according to claim 24 wherein the stubs include a central stub having edges that follow intersecting straight lines.

28. Apparatus according to claim 27 wherein the straight lines intersect at an angle of 90∀

V5 degrees.

29. Apparatus according to claim 24 wherein each element has a feed connection to a transmission line and a first segment of the edge of the element is rounded in a vicinity of the feed connection.

30. Apparatus according to claim 29 wherein the first segment merges into diverging straight segments which extend to corners of outer ones of the stubs.

31. Apparatus according to claim 24 wherein the stubs of the elements extend away from the centre line.

32. Apparatus according to claim 24 wherein each of the elements has three stubs.

33. Apparatus according to claim 24 wherein each of the stubs extends to a pointed corner at which segments of an edge of the element intersect.

34. Apparatus according to claim 23 wherein the antenna is matched directly to a 50 ohm unbalanced transmission line.

35. Apparatus according to claim 1 wherein the antenna system comprises at least one antenna that comprises a three-dimensional radiating element mounted directly to a circuit board over a ground plane on the circuit board, wherein the radiating element comprises an open end and a stub extended over the open end.

36. Apparatus according to claim 35 comprising an input feed point recessed from an edge of the radiating element.

37. Apparatus according to claim 36 wherein the stub and input feed point are at opposed ends of the radiating element.

38. Apparatus according to claim 35 wherein the radiating element tapers in width toward the open end.

39. Apparatus according to claim 35 wherein the radiating element comprises skirt portions that extend toward the ground plane along lateral edges of the radiating element.

40. Apparatus according to claim 1 wherein the monitoring station comprises a display and is configured to display on the display a heart rate detected by the sensor.

41. Apparatus according to claim 40 wherein the heart rate is measured in beats per minute.

42. Apparatus according claim 1 wherein the monitoring station comprises a display and is configured to display on the display a breathing rate detected by the sensor.

43. Apparatus according to claim 42 wherein the breathing rate is measured in breaths per minute.

44. Apparatus according to any claim 1 wherein the monitoring station comprises a display and is configured to display on the display indicia indicating whether or not the sensor detects a living subject.

45. Apparatus according to claim 1 wherein the monitoring station comprises a display and is configured to display on the display indicia indicating whether or not the sensor detects that a living subject is moving.

46. Apparatus according to claim 45 comprising means for monitoring a motion signal indicative of motions of a living subject and, based at least in part upon an amplitude or duration of the motion signal, determining that the motions of the living subject are not normal wherein the monitoring station is configured to display on the display indicia indicating that the motions of the living subject are not normal.

47. Apparatus according to claim 1 wherein the at least one sensor comprises a chair sensor, the chair sensor mounted on or built into a backrest of a chair.

48. Apparatus according to claim 1 wherein the at least one sensor and the monitoring station each comprises a wireless data transceiver and the information is transmitted from the at least one sensor to the monitoring station wirelessly by way of the wireless data transceivers.

49. Apparatus according to claim 1 wherein the ultra wideband radar system transmits pulses having frequencies less than about 12 GHz.

50. Apparatus according to claim 49 wherein the frequencies are in the range of about 3.6 GHz to about 4.6 GHz.

51. Apparatus according to claim 49 wherein the frequencies are in a band at about 6 GHz.

52. Apparatus according to claim 1 wherein the ultra wideband radar system transmits pulses with a pulse repetition interval in the range of about 0.5 μ

s to about 1 μ

s.

53. Apparatus according to claim 1 wherein the ultra wideband radar system comprises:

an oscillator;

a mixer connected to receive inputs from the oscillator and from reflected signals detected by the antenna system to produce a baseband signal at an output of the mixer; and

,

an analog-to-digital converter connected to digitize the baseband signal.

54. Apparatus according to claim 53 comprising an amplifier and a filter in a signal path between the antenna system and the mixer.

55. Apparatus according to claim 1 wherein the monitoring station comprises an audible alarm and the monitoring station is configured to sound the audible alarm in response to detecting that a subject being monitored has ceased breathing for more than a threshold time.

56. Apparatus according to claim 1 wherein the monitoring station comprises an audible alarm and the monitoring station is configured to sound the audible alarm in response to detecting that a breathing rate of a subject being monitored is outside of a preset range.

57. Apparatus according to claim 1 wherein the monitoring station comprises an audible alarm and the monitoring station is configured to sound the audible alarm in response to detecting that heart activity of a subject being monitored has ceased for more than a threshold time.

58. Apparatus according to any claim 1 wherein the monitoring station comprises an audible alarm and the monitoring station is configured to sound the audible alarm in response to detecting that a heart rate of a subject being monitored is outside of a preset range.

59. Apparatus according to claim 1 wherein the monitoring station comprises an audible alarm and the monitoring station is configured to sound the audible alarm in response to detecting that a subject being monitored is not present for more than a threshold time.

60. Apparatus according to claim 59 wherein the ultra wideband radar system is situated to detect presence of the person being monitored in a bed or chair.

61. Apparatus according to claim 1 the monitoring station comprises an audible alarm and the monitoring station is configured to sound the audible alarm in response to detecting abnormal motions of a subject being monitored.

62-63. -63. (canceled)