ADHERENT CARDIAC MONITOR WITH ADVANCED SENSING CAPABILITIES

• US 20130338448A1
• Filed: 05/24/2013
• Published: 12/19/2013
• Est. Priority Date: 09/14/2007
• Status: Active Grant

• Current Assignee: Medtronic Monitoring, Inc. (Medtronic Plc)
• Original Assignee: Corventis
• Inventors: Libbus, Imad, Manicka, Yatheendhar D., Fogoros, Rich
• Granted Patent: US 9,579,020 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 2560/0412 Low-profile patch shaped housings
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/061 Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body A61B1/00158 takes precedence
• 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 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/327 Generation of artificial ECG signals based on measured signals, e.g. to compensate for missing leads
• CPC Class Codes: A61B 5/332 Portable devices specially adapted therefor
• CPC Class Codes: A61B 5/4869 Determining body composition
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/6833 Adhesive patches
• CPC Class Codes: A61B 5/684 Indicating the position of the sensor on the body
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured
• CPC Class Codes: G01C 9/06 Electric or photoelectric indication or reading means

Abstract

An adherent device comprises an adhesive patch with at least two electrodes and an accelerometer. The accelerometer can be used to determine an orientation of the at least two measurement electrodes on a patient. By determining the orientation of the electrodes of the patch on the patient, physiologic measurements with the at least two electrodes can be adjusted and/or corrected in response to the orientation of the patch on the patient. The adherent patch and/or electrodes can be replaced with a second adherent patch and/or electrodes, and the orientation of the second adherent patch and/or electrodes can be determined with the accelerometer or a second accelerometer. The determined orientation of the second patch and/or electrodes on the patient can be used to correct measurements made with the second adherent patch and/or electrodes.

Claims

1-33. -33. (canceled)

34. A system for monitoring a patient, the system comprising:

a first adherent device having a first support with a first adhesive to adhere the first support to a skin of the patient, the first adherent device including first electrodes supported with the first support to couple to the skin of the patient, the first adherent device adapted to measure physiological parameters of the patient with the first electrodes when coupled to the skin of the patient during a first monitoring period, the first electrodes defining a first electrode axis;

a second adherent device having a second support with a second adhesive to adhere the second support to the skin of the patient, the second adherent device including second electrodes supported with the second support to couple to the skin of the patient, the second adherent device adapted to measure physiological parameters of the patient with the second electrodes when coupled to the skin of the patient during a second monitoring period subsequent the first monitoring period, the second electrodes define a second electrode axis;

at least one accelerometer couplable to at least one of the first adherent device or the second adherent device and adapted to determine an orientation of the respective electrode axis of the first electrodes or the second electrodes relative a reference axis of the patient when coupled to the first or second adherent device first coupled to the patient during the respective monitoring periods; and

a processor system comprising a tangible medium configured to modify the measured physiological parameters based on the determined orientations of the first electrode axis or the second electrode axis such that errors in the physiological parameter measurements associated with changes in the orientation of the first and second adherent devices are reduced.

35. The system of claim 34, wherein the at least one accelerometer comprises a first accelerometer coupled to the first adherent device in a first predetermined orientation and a second accelerometer coupled to the second adherent device in a second predetermined orientation.

41. The system of claim 34 wherein the reference axis of the patient corresponds to a vertical axis of the patient that extends vertically when the patient is standing or sitting.

47. The system of claim 34, wherein each of the first and second supports is adapted to remain coupled to the skin of the patient for the entire respective monitoring period such that adhering the first and second adherent devices to the patient sequentially provides physiological measurement data during a monitoring duration including both the first monitoring period and the second monitoring period.

48. The system of claim 47, wherein one or both of the first and second monitoring period is 90 days or more.

49. The system of claim 34, further comprising:

an intermediate device communicatively coupled to each of the first and second adherent devices through wireless communication, the intermediate device configured to wirelessly receive the physiological measurements from each of the first and second adherent devices when coupled to the skin of the patient.

50. The system of claim 47, further comprising:

a remote server communicatively coupled with the intermediate device such that the remote server receives the physiological measurements from the intermediate device for physiological monitoring of the patient.

36-40. -40. (canceled)

42. A system for monitoring a patient, the system comprising:

a first adherent measurement device comprising a first support with a first adhesive to adhere the first support to a skin of the patient, the first adherent measurement device comprising a first accelerometer and a first at least two measurement electrodes, the first adherent device comprising first measurement circuitry to measure a first accelerometer signal with the accelerometer and a first electrocardiogram signal with the first at least two measurement electrodes during a first monitoring period;

a second adherent measurement device comprising a second support with a second adhesive to adhere the second support to a skin of the patient, the second adherent measurement device comprising a second accelerometer and a second at least two measurement electrodes, the second accelerometer comprising second circuitry to measure a second accelerometer signal with the second accelerometer and a second electrocardiogram signal with the second at least two measurement electrodes during a second monitoring period subsequent the first monitoring period; and

a processor system comprising a tangible medium configured to combine the first electrocardiogram signal with the second electrocardiogram signal in response to the first accelerometer signal and the second accelerometer signal.

43. The system of claim 42 wherein the first accelerometer comprises a first accelerometer measurement axis and the first at least two electrodes are separated by a first distance to define a first electrode measurement axis, the first accelerometer measurement axis aligned with the first electrode measurement axis, and wherein the second accelerometer comprises a second accelerometer measurement axis and the second at least two electrodes are separated by a second distance to define a second electrode measurement axis, the second accelerometer measurement axis aligned with the second electrode measurement axis.

44. The system of claim 42 wherein the processor system is configured to determine an orientation of the first electrode measurement axis relative a reference axis of the patient in response to the first accelerometer signal and determine an orientation of the second electrode measurement axis relative the reference axis of the patient in response to the to the accelerometer signal, wherein the reference axis corresponds to a vertical axis of the patient that extends vertically along the patient when the patient is standing or sitting.

45. The system of claim 42 wherein the processor system comprises at least one processor supported with at least one of the first support or the second support, the at least one processor configured to combine the first electrocardiogram signal and the second electrocardiogram signal in response to the first accelerometer signal and the second accelerometer signal.

46. The system of claim 42 wherein the processor is configured to scale each signal and sum the scaled signals together to combine the signals.

51. A method of monitoring a patient, the method comprising:

adhering a first adherent device to a skin of the patient, the adherent device comprising a first accelerometer and at least two physiological measurement electrodes, the at least two physiological measurement electrodes separated by a distance to define an electrode measurement axis;

measuring an accelerometer signal from the accelerometer of the first adherent device when the first adherent device is adhered to the patient;

determining a reference axis of the patient corresponding to a vertical axis that extends vertically along the patient when the patient is standing and determining an orientation of the electrode measurement axis of the first adherent device relative the reference axis in response to the accelerometer signal of the first adherent device;

measuring physiological parameters of the patient with the at least two physiological measurement electrodes of the first adherent device when coupled to the skin of the patient;

adhering a second adherent device to a skin of the patient, the adherent device comprising the first accelerometer or a second accelerometer and at least two physiological measurement electrodes, the at least two physiological measurement electrodes separated by a distance to define an electrode measurement axis;

measuring an accelerometer signal from the accelerometer of the second adherent device when the second adherent device is adhered to the patient;

determining an orientation of the electrode measurement axis of the second adherent device relative the reference axis of the patient in response to the accelerometer signal of the second adherent device;

removing the first adherent device from the patient; and

measuring physiological parameters of the patient with the at least two physiological measurement electrodes of the second adherent device and modifying the physiological parameter measurements obtained from the second adherent device based on the determined orientation of the electrode measurement axis of the second adherent device relative the reference axis of the patient such that differences in the measured physiological parameters associated with changes in the orientation of the first and second adherent devices are reduced.

52. The method of claim 51 wherein the first accelerometer or the first and second accelerometers each comprises at least one measurement axis sensitive to gravity aligned with the electrode measurement axis.

53. The method of claim 51 wherein the first accelerometer or the first and second accelerometers each comprises at least one accelerometer measurement axis sensitive to gravity, the at least one accelerometer measurement axis configured to extend substantially horizontally on the patient when the device is adhered to the patient.

54. The method of claim 51 wherein the accelerometer signal of the first accelerometer or of the first and second accelerometers corresponds to at least one accelerometer measurement vector in a direction along the at least one accelerometer measurement axis.

55. The method of claim 51 wherein the first accelerometer or the first and second accelerometers each comprises at least one accelerometer measurement axis sensitive to gravity and wherein the at least one accelerometer measurement axis is oriented with respect to the electrode measurement axis in a predetermined configuration.

56. The method of claim 51 wherein each of the first and second adherent devices comprises an adherent surface to adhere to a skin of the patient and wherein the electrode measurement axis extends along the adherent surface.

57. The method of claim 51 wherein the first accelerometer or the first and second accelerometers each comprises three axes, wherein a first axis and a second axis of the three axes extend along the measurement surface and a third axis of the three axes extends away from the measurement surface and the accelerometer measurement signal corresponds to three orthogonal measurement vectors, wherein each of the three orthogonal measurement vectors extends along one of the accelerometer measurement axes.

58. The method of claim 51 further comprising measuring an electrocardiogram signal with the at least two measurement electrodes of each of the first and second adherent devices when coupled to the patient and modifying the electrocardiogram signal of the second adherent device in response to the accelerometer signal.

59. The method of claim 58 wherein modifying comprises rotating the electrocardiogram vector in response to the accelerometer signal to obtain a standard electrocardiogram vector.

60. The method of claim 59 wherein an amplitude and a direction of features of the electrocardiogram signal are modified to approximate a standard electrocardiogram vector.

61. The method of claim 51, further comprising:

receiving physiological measurements from the at least two physiological measurement electrodes of each of the first adherent device with an intermediate device wirelessly coupled with each of the first adherent device and second adherent device when coupled to the skin of the patient.

62. The method of claim 61, further comprising:

receiving physiological measurements from the intermediate device by a remote server communicatively coupled with the intermediate device such that the remote server receives the physiological measurements from the intermediate device for physiological monitoring of the patient.

63. The method of claim 62, wherein modifying the physiological measurement data is performed by a processor of the remote server.

64. The method of claim 51, wherein the second adherent device is adhered before removal of the first adherent device.

65. The method of claim 51, wherein the second adherent device is adhered after removal of the first adherent device.

66. The method of claim 51, further comprising:

removing the accelerometer from the first adherent device and coupling the accelerometer to the second adherent device such that the first and second adherent devices utilize the same accelerometer.