Obstructive sleep apnea treatment devices, systems and methods

• US 20080103545A1
• Filed: 10/12/2007
• Published: 05/01/2008
• Est. Priority Date: 10/13/2006
• Status: Active Grant

• Current Assignee: LivaNova USA, Inc. (LivaNova Plc)
• Original Assignee: Apnex Medical, Inc.
• Inventors: Kuhnley, Brian, Jasperson, Keith, Thorp, Christopher, Tesfayesus, Wondimeneh, Kaplan, Paula, Atkinson, Robert, Bolea, Stephen, Persson, Bruce, Hauschild, Sidney, Hoegh, Thomas
• Granted Patent: US 8,417,343 B2
• Time in Patent Office: Days
• US Class Current: 607/42
• CPC Class Codes: A61B 5/0809 by impedance pneumography
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61N 1/0556 Cuff electrodes
• CPC Class Codes: A61N 1/0558 Anchoring or fixation means therefor
• CPC Class Codes: A61N 1/3601 of respiratory organs
• CPC Class Codes: A61N 1/3606 adapted for a particular treatment
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna

Abstract

Devices, systems and methods for nerve stimulation for OSA therapy.

Claims

1-56. -56. (canceled)

57. A method using an implanted medical device having electrodes for measuring respiration, the method comprising:

sampling a bio-impedance measurement along a short distance vector first to determine if the short distance vector is producing a signal sufficiently adequate to be an indicator of respiration, wherein the short distance vector includes a path between two electrodes spaced by a first distance;

sampling a bio-impedance measurement along an intermediate distance vector if the short distance vector is not producing a signal sufficiently adequate to be an indicator of respiration, wherein the intermediate distance vector includes a path between two electrodes spaced by a second distance larger than the first distance; and

sampling a bio-impedance measurement along a long distance vector if the intermediate distance vector is not producing a signal sufficiently adequate to be an indicator of respiration, wherein the long distance vector includes a path between a two electrodes spaced by a third distance larger than the second distance.

58. The method of claim 57, further comprising:

selecting a vector from the short distance vector, intermediate distance vector, and long distance vector that is producing a signal sufficiently adequate to be an indicator of respiration; and

stimulating a nerve innervating an upper airway dilator muscle via a chronically implanted an electrode on the nerve.

59. A method of using an implanted medical device by switching between a plurality of sensed signals, the method comprising:

providing a plurality of sensed signals to a channel selection switch;

identifying a plurality of fiducials for each of the plurality of sensed signals;

analyzing the fiducials of each of the plurality of sensed signals to determine which of the sensed signals is the best indicator of a patient'"'"'s respiration;

identifying the sensed signal that is the best indicator of a patient'"'"'s respiration as a primary signal;

storing the identified fiducials for at least the signals not identified as the primary signal;

analyzing the stored fiducials to determine if any of the signals not identified as the primary signal are a better indicator of a patient'"'"'s respiration than the primary signal;

identifying the signal that is the better indicator of a patient'"'"'s respiration as the secondary signal; and

switching to the secondary signal for respiration detection.

60. The method of claim 59, wherein each of the plurality of sensed signals is a bio-impedance measurement.

61. A method of using an implanted medical device by monitoring a chronically implanted stimulation lead, the method comprising:

providing an implantable electrical stimulator having an impedance sensing circuit for sensing a parameter indicative of respiration;

providing an impedance sensor connected to the impedance sensing circuit;

providing a stimulation lead connected to the stimulator, the stimulation lead including a distal electrode;

providing a switching circuit operably coupled to the impedance sensing circuit; and

via the switching circuit, selectively coupling the impedance sensing circuit to the stimulation lead.

62. The method of claim 61, wherein the impedance sensing circuit measures an impedance within the stimulation lead.

63. The method of claim 61, wherein the impedance sensing circuit measures a tissue impedance at the distal electrode.

64-69. -69. (canceled)

70. A method of treating obstructive sleep apnea, the method comprising:

chronically implanting an electrode on a nerve innervating an upper airway dilator muscle;

sensing a measure of respiration for a plurality of respiratory cycles including inspiratory and expiratory phases;

identifying the respiratory cycle period;

analyzing the measure of respiration to identify the onset of the expiratory phase for each respiratory cycle;

predicting the onset of a future expiratory phase; and

beginning stimulation of the nerve a fraction of a respiratory cycle period before the onset of the future expiratory phase.

71. The method of claim 70, wherein the fraction ranges between 30/100 and 50/100.

72. The method of claim 70, wherein fraction is selectively adjustable.

73. The method of claim 70, wherein the measure of respiration is bio-impedance.

77. The method of claim 70, wherein the method further comprises:

obtaining a respiration signal;

providing a signal to the electrode at a rate to stimulate the patient'"'"'s nerve, based on the obtained respiration signal;

determining that the respiration signal has experienced a loss; and

continuing stimulation of the nerve at substantially the rate before the respiratory signal was lost.

74. A method of treating obstructive sleep apnea, the method comprising:

obtaining a respiration waveform for a respiratory cycle including inspiratory and expiratory phases;

identifying the respiratory cycle period;

identifying the onset of the expiratory phase for the respiratory cycle;

predicting the onset of a future expiratory phase; and

stimulating a nerve to cause dilation of a patient'"'"'s upper airway, wherein stimulation of the nerve begins a fraction of a respiratory cycle period before the onset of the future expiratory phase.

75. The method of claim 74, wherein fraction is selectively adjustable.

76. The method of claim 74, wherein identifying the onset of the expiratory phase includes identifying a peak of the respiration waveform.

78. (canceled)

79. A method of using an implanted medical device having electrodes for measuring bio-impedance, the method comprising:

providing a first vector and a second vector, wherein each vector is defined by electrodes spaced from each other;

chronically implanting the electrodes;

measuring a first bio-impedance across the first vector;

measuring a second bio-impedance across the second vector;

comparing the first and second bio-impedance measurements; and

selecting one of the first and second bio-impedance measurements as a preferred indicator of respiration.

80. A method as in claim 79, the method further comprising:

switching to the other of the first and second bio-impedance measurement if the selected bio-impedance measurement is no longer a preferred indicator of respiration.

81. A method as in claim 79, wherein the first and second vectors share a common electrode.

82. A method as in claim 79, further comprising:

providing a third vector defined by electrodes spaced from each other;

measuring a third bio-impedance across the third vector;

scanning the first, second, and third bio-impedance measurements for a secondary indicator of respiration, before the bio-impedance measurement selected as the preferred indicator of respiration becomes an inadequate indicator of respiration; and

selecting the bio-impedance measurement designated the secondary indicator of respiration if the bio-impedance measurement designated as the preferred indicator of respiration is not an adequate indicator of respiration.