Method and device for sleep monitoring

• US 6,752,766 B2
• Filed: 01/28/2002
• Issued: 06/22/2004
• Est. Priority Date: 01/30/2001
• Status: Expired due to Fees

• Current Assignee: Peter Kowallik, Wirtz Hubert
• Original Assignee: Peter Kowallik, Wirtz Hubert
• Inventors: Kowallik, Peter, Hubert, Wirtz
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US10/058,703
• Publication Number:
  US 20020169384A1
• Time in Patent Office: 876 Days
• Field of Search: 600/529-538, 128/204.23
• US Class Current: 600/538
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/026 specially adapted for predicting, e.g. for determining an information representative of a flow limitation during a ventilation cycle by using a root square technique or a regression analysis
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2230/005 Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/04 Heartbeat characteristics, e.g. ECG, blood pressure modulation
• CPC Class Codes: A61M 2230/10 Electroencephalographic signals
• CPC Class Codes: A61M 2230/42 Rate

Abstract

A method of identifying a minimum of one breathing parameter which is characteristic for the breathing status of a sleeping individual comprises the following steps: measurement of the derivative trend with respect to time of a minimum of one variable of state of the cardiovascular system of the individual, which variable recurrently changes with the respiration; determination of breath-to-breath intervals, each of which represents the duration of one breath, from the results of the measurement; and identification of the breathing parameter which is defined by the variability of the breath-to-breath intervals in phases of unobstructed breathing and/or statistical variables derived therefrom. In addition, applications of the method of controlling breathing apparatuses and of signaling breathing statuses of sleeping individuals as well as devices for implementing the methods are described.

Claims

1. A method of detecting a minimum of one breathing parameter that is characteristic for the breathing status of a sleeping individual, comprising the following steps:

measuring of the derivative trend with respect to time of a minimum of one variable of state of the cardiovascular system of the individual, which variable changes recurrently during respiration, determining of breath-to-breath intervals, each of which represents the duration of one breath, based on the results of the measurement, and determining of the breathing parameter which is identified by the variability of the breath-to-breath intervals in phases of unobstructed breathing and/or statistical variables derived therefrom.

2. The method as in claim 1 in which the breathing parameter determined is the standard deviation and/or the kurtosis value of breath-to-breath intervals.

3. The method as in claim 1, in which the variable of state measured is the respiratory flow and/or an ECG signal.

4. The method as in claim 1, including subjecting the measured breath-to-breath intervals to a time filter to determine the phases of unobstructed breathing.

5. The method as in claim 1, including comparing at least one breathing parameter determined is to a reference value and an actuating signal for a breathing and/or signaling device is generated as a function of this comparison.

6. The method of controlling a breathing apparatus as in claim 1, including controlling a pressure generator of the breathing apparatus is a function of at least one breathing parameter which was determined using a method described in accordance with the recited steps.

7. The method as in claim 6 including generating an increased breathing pressure by using the pressure generator if at least one breathing parameter is characteristic for the presence of a breathing disturbance.

12. A computer program embodied on a computer readable medium for implementing a method of detecting a minimum of one breathing parameter that is characteristic for the breathing status of a sleeping individual in accordance with claim 1.

8. A method of signaling and/or registering a breathing stage, including generating an actuating signal for triggering a signaling device as a function of at least one breathing parameter which was identified by the variability of the breath-to-breath intervals in phases of unobstructed breathing and/or statistical variables derived therefrom.

9. The method as in claim 8, in which the signaling device generates acoustic signals or visual signals, in particular a light-emitting diode display and/or screen display, or activates a logging printer.

10. A method of analyzing the rhythm of measured variables of state of the cardiovascular system of an individual, which variables change over time in correlation with the respiration, comprising the following steps:

time filtering of measured breath-to-breath intervals with determination of all breath-to-breath intervals which are shorter than a predetermined threshold value and in which respiration is unobstructed,

statistically analyzed the filtered breath-to-breath intervals, with the determination of statistical variables which are characteristic for the frequency distribution of the duration of the breath-to-breath intervals, and

outputting, displaying and/or storing of the determined statistical variables as breathing parameters.

11. The method as in claim 10, in which the statistical variables comprise the standard deviation and/or the kurtosis value of the breath-to-breath intervals in phases of unobstructed breathing.

13. A device for artificially ventilating a patient and/or for signaling sleep stages, comprising:

a control device which is designed to detect a minimum of one breathing parameter from measured breath-to-breath intervals which is characteristic for the breathing status of a sleeping individual and which comprises a comparator for comparing at least said one breathing parameter to a reference value, with the control device being designed to generate an actuating signal as a function of the result of the comparison, and

a breathing apparatus and/or a signaling device which can be controlled with the actuating signal.

14. The device as in claim 13, in which the breathing device comprises a pressure generator which can be controlled by means of the actuating signal.

15. The device as in claim 13, in which the breathing device comprises a CPAP device.

16. The device as in claim 13, comprising a measuring device which is connected to the individual via sensors and which is designed so as to allow the measurement of the derivative trend with respect to time of at least one variable of state of the cardiovascular system of the individual, which variable recurrently changes with the respiration.

17. The device as in claim 16, in which the sensors comprise a thermistor (12) and/or an ECG electrode layout.

18. The device as in claim 13, in which the signaling device comprises a sound generator, a printer and/or a display unit.

19. The method of use of a device as claimed in claim 13 for the diagnosis or treatment of sleep-disordered breathing.