Apparatus and Method for Breathing Pattern Determination Using a Non-Contact Microphone

• US 20080319333A1
• Filed: 07/21/2005
• Published: 12/25/2008
• Est. Priority Date: 07/23/2004
• Status: Active Grant

• Current Assignee: 2breathe Technologies Ltd
• Original Assignee: InterCure Ltd.
• Inventors: Doron, Yoram, Gavish, Benjamin
• Granted Patent: US 7,850,619 B2
• Time in Patent Office: Days
• US Class Current: 600/529
• 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 5/74 Details of notification to user or communication with user or patient indicating measured values G01D7/00; user input means input or output arrangements for computers G06F3/00
• CPC Class Codes: A61B 7/003 Detecting lung or respiration noise
• CPC Class Codes: A61M 15/00 Inhalators drug delivery in endotracheal tubes A61M16/04

Abstract

A method is provided for analyzing respiration of a subject (20). Using a non-contact microphone (22), a raw signal indicative of airflow sounds of the respiration is generated. The raw signal is analyzed to determine a first set of one or more parameters of the respiration. An algorithm is applied to the first set of parameters to derive a second set of one or more estimated parameters of the respiration that are not generally directly measurable in the raw signal. Other embodiments are also described.

Claims

1-88. -88. (canceled)

89. Apparatus for analyzing respiration of a subject, comprising:

a non-contact microphone, adapted to generate a raw, signal representing airflow sounds of the respiration; and

a control unit, adapted to;

analyze the raw signal to determine a first set of one or more parameters of the respiration, and apply an algorithm to the first set of parameters to derive a second set of one or more estimated parameters of the respiration that are not generally directly measurable in the raw signal.

90. The apparatus according to claim 89, wherein the control unit adapted to set the second set of one or more estimated parameters equal to a phenomenological function of the first set of one or more parameters.

91. The apparatus according to claim 89, wherein the first set of parameters includes a measure of breathing amplitude of the respiration, and wherein the control unit is adapted to analyze the raw signal by integrating the airflow sounds for a breath of the respiration to determine the measure of the breathing amplitude.

92. The apparatus according to claim 89, wherein the first set of parameters includes a measure of breathing amplitude of the respiration, wherein the second set or parameters is selected from the list consisting of:

a measure of ventilation of the subject, and a measure of breathing irregularity of the subject, and wherein the control unit is adapted to apply the algorithm to the measure of breathing amplitude to derive the selected second set of parameters.

93. The apparatus according to claim 89, wherein the control unit is adapted to analyze at least one of the first and second sets of parameters to derive at least one additional breathing-related parameter of the subject selected from the list consisting of:

breathing amplitude, a geometrical property of airflow of the subject, a characteristic of the airflow indicative of pursed lips breathing, a characteristic of the breathing indicative of relaxed breathing, a characteristic of the breathing indicative of passive elastic recoil of lungs of the subject, a characteristic of breathing with effort, and a characteristic of breathing during which the lungs of the subject under go a functional change.

94. The apparatus according to claim 89, comprising an output generator, wherein the control unit is adapted to drive the output generator to guide the subject to perform breathing in a plurality of respiration phases determined at least in part responsively to the second set of parameters.

95. The apparatus according to claim 89, wherein the non-contact microphone comprises a non-contact microphone of a consumer electronics device capable of performing at least one function that does not facilitate analyzing respiration of the subject.

96. The apparatus according to claim 89, wherein the non-contact microphone is integrated into a medical device in fluid communication with respiration-related airflow of the subject.

97. The apparatus according to claim 96, wherein the medical device comprises a drug inhaler.

98. The apparatus according to claim 89, wherein the control unit is adapted to derive an expiratory airflow sound signal, from the raw signal, and to analyze the expiratory airflow sound signal to determine the first set of parameters.

99. The apparatus according to claim 98, comprising an output generator, wherein the control unit is adapted to drive the output generator to generate a real-time indication for the subject that indicates whether expiration has been detected.

100. The apparatus according to claim 98, wherein the first set of parameters includes an active expiration time and a breathing period of the subject, and wherein the control unit is adapted to analyze the expiratory airflow sound signal to determine the active expiration time and the breathing period.

101. The apparatus according to claim 100, wherein the second set of parameters includes an amplitude of a non-expiratory portion of the respiration, and wherein the control unit is adapted to apply the algorithm to derive the amplitude of the non-expiratory portion of the respiration.

102. The apparatus according to claim 100, wherein the second set of parameters includes an inspiration time of the subject, and wherein the control unit is adapted to apply the algorithm to derive the inspiration time.

103. The apparatus according to claim 102, wherein the control unit is adapted to apply the algorithm to derive the inspirational time by:

determining whether a difference between the breathing period and the active expiration time is greater than or equal to a first function of the active expiration time, responsively to a positive determination, setting the inspiration time equal to a second function of the difference, and responsively to a negative determination, setting the inspiration time equal to a third function of the active expiration time.

104. The apparatus according to claim 103, wherein the control unit is adapted to determine whether the difference between the breathing period and the active expiration time is greater than or equal to the active expiration time.

105. The apparatus according to claim 103, wherein the control unit is adapted to, responsively to the positive determination, set the inspiration time equal to a value within plus or minus 20% of the difference.

106. The apparatus according to claim 105, wherein the control unit is adapted to, responsively to the positive determination, set the inspiration time equal to a value within plus or minus 10% of the difference.

107. The apparatus according to claim 103, wherein the second function includes a function of the difference and a phenomenological constant, and wherein the control unit is adapted to, responsively to the positive determination, set the inspiration time equal to the second function of the difference and the phenomenological constant.

108. The apparatus according to claim 107, wherein the control unit is adapted to determine the phenomenological constant at least in part responsively to at least one parameter of the first set of one or more parameters.

109-173. -173. (canceled)