NON-CONTACT PHYSIOLOGIC MOTION SENSORS AND METHODS FOR USE

• US 20100152600A1
• Filed: 10/07/2009
• Published: 06/17/2010
• Est. Priority Date: 04/03/2008
• Status: Abandoned Application

• Current Assignee: Kai Medical, Inc.
• Original Assignee: Kai Sensors, Inc.
• Inventors: Yamada, Shuhei, Shing, Tommy, Hourani, Charles El, Park, Byung Kwon, Droitcour, Amy, Vergara, Alex
• Application Number:
  US12/575,447
• Publication Number:
  US 20100152600A1
• Time in Patent Office: Days
• US Class Current: 600/534
• CPC Class Codes: A61B 2560/0204 of power management
• 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 5/1102 Ballistocardiography
• CPC Class Codes: A61B 5/1113 Local tracking of patients, e.g. in a hospital or private home
• CPC Class Codes: A61B 5/1114 Tracking parts of the body
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/165 Evaluating the state of mind, e.g. depression, anxiety
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: G01S 13/534 based upon amplitude or phase shift resulting from movement of objects, with reference to the surrounding clutter echo signal, e.g. non coherent MTi, clutter referenced MTi, externally coherent MTi
• 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 13/583 using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets
• CPC Class Codes: G01S 13/88 Radar or analogous systems specially adapted for specific applications electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00
• CPC Class Codes: G01S 7/2886 using I/Q processing
• CPC Class Codes: G01S 7/358 using I/Q processing
• CPC Class Codes: Y02A 90/10 : Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

A radar-based physiological motion sensor is disclosed. Doppler-shifted signals can be extracted from the signals received by the sensor. The Doppler-shifted signals can be digitized and processed subsequently to extract information related to the cardiopulmonary motion in one or more subjects. The information can include respiratory rates, heart rates, waveforms due to respiratory and cardiac activity, direction of arrival, abnormal or paradoxical breathing, etc. In various embodiments, the extracted information can be displayed on a display.

Claims

1-37. -37. (canceled)

38. A system for sensing a physiological motion, said system comprising:

one or more antennas configured to transmit electromagnetic radiation;

one or more antennas configured to receive electromagnetic radiation;

at least one processor configured to extract information related to cardiopulmonary motion by executing at least one of a demodulation module, a non-cardiopulmonary motion detection module, and a rate estimation module; and

a communications system configured to communicate with an output device, said output device configured to output information related to the cardiopulmonary motion.

39. The system of claim 38, wherein the device provides a spot check or point-in-time measurement of vital signs.

40. The system of claim 39, wherein vital signs comprise a respiratory rate.

41. The system of claim 38, wherein the device provides a continuous monitoring of vital signs.

42. The system of claim 41, wherein vital signs comprise a respiratory waveform or a cardiac waveform.

43. The system of claim 38, wherein the source of radiation comprises a voltage-controlled oscillator, which is phase-locked to a crystal with a phase-lock loop circuit, such that the frequency of the radiation can be selected within a band, providing a tunable frequency synthesizer and frequency selectivity.

44. The system of claim 38, wherein the antenna is configured to transmit and receive electromagnetic radiation, and the antenna comprises an array of metal elements with an air gap between the elements and the ground plane.

45. The system of claim 43, wherein spread spectrum techniques are used to introduce a pseudo-random phase noise to the frequency synthesizer utilizing the phase-locked oscillator.

46. The system of claim 38, wherein the system comprises a direct-conversion receiver with an active I/Q demodulator to provide differential quadrature signals, a differential signals conditioning stage with filtering and amplification, and a differential-input analog-to-digital converter.

47. The system of claim 46, wherein the signal conditioning provides a DC-coupled signal, and the ADC is high-resolution.

48. The system of claim 47, where the resolution of the ADC is 24 bits.

49. The system of claim 38, wherein the system is powered through 5V USB bus power.

50. The system of claim 38, wherein the system comprises a radio and processor integrated in the same housing.

51. The system of claim 38, wherein the processor runs the modules and provides rate and other information to a separate host computer.

52. The system of claim 51, wherein a host computer provides a command over a communications interface to initiate measurements.

53. The system of claim 38, wherein the device includes an integrated light source to provide feedback on the proper aiming of the device.

54. The system of claim 53, wherein the light source comprises a relatively high-intensity directional LED.

55. The system of claim 53, wherein the integrated light source illuminates the areas included in the antenna field of view.

56. The system of claim 53, wherein the system comprises a button that can be used to turn the light source on and off.

57. The system of claim 38, wherein the system comprises an integrated display.

58. The system of claim 57, wherein the sensor'"'"'s integrated display provides feedback messages including progress, error messages, retry messages, low-signal information, results, and other information.

59. The system of claim 38, wherein the system includes relatively real-time audio feedback, such that if the system is aimed improperly such that the signal power is low, there is an audible indication.

60. A method of sensing motion using a motion sensor, the method comprising:

generating electromagnetic radiation from a source of radiation, wherein the frequency of the electromagnetic radiation is in the radio frequency range;

transmitting the electromagnetic radiation towards a subject using one or more transmitters;

receiving a radiation scattered at least by the subject using one or more receivers;

extracting a Doppler shifted signal from the scattered radiation;

transforming the Doppler shifted signal to a digitized motion signal, said digitized motion signal comprising one or more frames, wherein the one or more frames comprise time sampled quadrature values of the digitized motion signal;

demodulating said one or more frames using a demodulation module executed by a processor to isolate a signal corresponding to a physiological movement of the subject or a part of the subject;

analyzing the signal to obtain information corresponding to a non-cardiopulmonary motion or other signal interference;

processing the signal to obtain information corresponding to the physiological movement of the subject or a part of the subject;

estimating point-in time vital signs parameters at a pre-determined intervals; and

communicating the information to an output system that is configured to perform an output action.

61. The method of claim 60, wherein the output action comprises the display of a history of point-in-time measurements, including values and times, such that trends can be viewed.

62. The method of claim 60, wherein estimating point in time vital signs parameters comprises determining the length of the measurement interval by using an interval selection module that utilizes the information corresponding to a non-cardiopulmonary motion or other signal interference and information corresponding to the physiological movement of the subject or a part of the subject.

63. The method of claim 60, wherein the pre-determined intervals are user selectable from a menu of intervals.

64. The method of claim 60, wherein the pre-determined intervals can be selected by the user.

65. The method of claim 60, wherein an external device controls a device which estimates point-in-time vital signs parameters by sending commands for when to start measurements.

66. The method of claim 65, wherein the external device comprises a computer.

67. The method of claim 65 wherein the external device comprises a vital signs measurement device or a patient monitor.

68-129. -129. (canceled)