Method and apparatus for controlling sleep disorder breathing

• US 5,203,343 A
• Filed: 06/14/1991
• Issued: 04/20/1993
• Est. Priority Date: 06/14/1991
• Status: Expired due to Term

• Current Assignee: Respironics Incorporated
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Behbehani, Khosrow, Burk, John R., Lucas, Edgar A., Yen, Fu-Chung, Axe, John R.
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): Nasser, Jr., Robert L.
• Application Number:
  US07/715,374
• Time in Patent Office: 676 Days
• Field of Search: 128/721, 128/716, 128/724, 128/725, 128/848
• US Class Current: 600/538
• CPC Class Codes: A61F 5/56 Devices for preventing snoring by influencing the respiratory system by gas treatment A61M16/00
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/702 automatically during use
• CPC Class Codes: A61M 2230/40 Respiratory characteristics

Abstract

A method and device for controlling sleep disorder breathing utilizes variable pressure. The compressor supplies air at a relatively low pressure to the user'"'"'s air passages while the user is asleep. A pressure transducer will monitor the pressure and convert the pressure into an electrical signal. The electrical signal is filtered and processed to compare it to the characteristics of waveforms that exists during snoring. If the envelope of the waveform exceeds an average threshold value in duration and in area, then the microprocessor will consider the envelope possibly associated with a snore. If a selected number of envelopes of this nature occur within a selected time period, then the microprocessor considers snoring to exist and increases the pressure of the compressor. If snoring is not detected within a certain time period, then the microprocessor lowers the level gradually.

Claims

1. A method for controlling sleep disorder breathing of a person, comprising:

connecting an interface from a source of air pressure to the person'"'"'s nostril passages;

supplying air pressure from the source through the interface to the person'"'"'s nostril passages;

monitoring the air pressure in the interface to detect an onset of sleep disorder breathing;

then

increasing the air pressure if the onset of sleep disorder breathing is detected while continuing to monitor the air pressure in the interface for the onset of sleep disorder breathing; and

wherein the step of monitoring the air pressure in the interface comprises;

sensing pressure waveforms resulting from the person'"'"'s breathing;

filtering the sensed waveforms to pass only frequencies of a selected range;

determining a present energy level of each of the filtered waveforms;

comparing the present energy level determined to an average energy level of previously filtered waveforms by the same person; and

if the present energy level determined falls within a selected range based on the average energy level,

counting the number of waveforms that fall within the range within a selected time period, and if the number is within a selected amount, then providing a signal to increase the air pressure.

2. A method for controlling sleep disorder breathing of a person, comprising:

(a) connecting an interface from a source of air pressure to the person'"'"'s nostril passages;

(b) supplying air pressure from the source through the interface to the person'"'"'s nostril passages;

(c) monitoring the air pressure in the interface to detect snoring;

then

(d) increasing the air pressure if snoring is detected while continuing to monitor the air pressure in the interface for the continuance of snoring;

then

(e) after a selected time period, if snoring is still being detected, further increasing the air pressure;

then

(f) repeating step (e) until a maximum level of air pressure is reached; and

(g) gradually reducing the air pressure after a selected time period if snoring is not detected; and

wherein the step of detecting snoring comprises;

sensing pressure waveforms in the interface occurring as a result of the person'"'"'s breathing;

filtering the sensed waveforms to pass only a selected frequency range of filtered waveforms associated with snoring;

determining a present area for each of the filtered waveforms;

determining a present duration for each of the filtered waveforms;

computing an average area based on areas computed for a selected number of previous filtered waveforms of the same person;

computing an average duration based on durations computed for a selected number of previous filtered waveforms of the same person;

comparing the present area to the average area and comparing the present duration to the average duration; and

if the present area and the present duration fall within selected ranges of the average area and average duration,

counting the number of filtered waveforms that fall within the ranges within a selected time period, and if the number is within a selected amount, then increasing the air pressure.

3. A method for controlling sleep disorder breathing of a person, comprising:

(a) connecting an interface from a source of air pressure to the person'"'"'s nostril passages;

(b) supplying air pressure from the source to the person'"'"'s nostril passages;

(c) sensing pressure waveforms in the interface occurring as a result of the person'"'"'s breathing;

(d) filtering the sensed waveforms to pass only filtered waveforms within a selected frequency range associated with snoring;

(e) determining selected values of the filtered waveforms and comparing the values to average values of waveforms associated with the person'"'"'s snoring to determine if the filtered waveforms fall within a selected range;

(f) counting the number of filtered waveforms that fall within the range within a selected time period; and

if the number is within a selected amount to indicate snoring associated with sleep disorder breathing,

(g) increasing the air pressure;

then

(h) after a selected time period, further increasing the air pressure if snoring associated with sleep disorder breathing is still being detected while continuing to monitor the air pressure in the interface for the continuance of snoring;

then

(i) repeating step (h) until a selected maximum level of air pressure is reached; and

(j) reducing the air pressure in a controlled manner to a selected minimum after a selected time period if snoring associated with sleep disorder breathing is not being detected.

4. The method according to claim 3 wherein step (e) comprises:

determining a present area for each of the filtered waveforms;

determining a present duration for each of the filtered waveforms;

computing an average area based on areas computed for a selected number of previous filtered waveforms of the same person;

computing an average duration based on durations computed for a selected number of previous filtered waveforms of the same person; and

comparing the present area to the average area and comparing the present duration to the average duration to determine if the present area and the present duration fall within selected ranges of the average area and average duration.

5. An apparatus for controlling sleep disorder breathing of a person, comprising in combination:

a source of air pressure;

an interface having one end connected to the source of air pressure and another end adapted to fit over the person'"'"'s nostril passages to supply air pressure from the source to the person'"'"'s nostril passages;

means for monitoring the air pressure in the interface to detect an onset of sleep disorder breathing;

means for automatically increasing the air pressure if the onset of sleep disorder breathing is detected; and

wherein the means for monitoring the air pressure in the interface comprises;

means for sensing pressure waveforms resulting from the person'"'"'s breathing;

means for filtering the sensed waveforms to pass only frequencies of a selected range;

means for determining a present energy level of each of the filtered waveforms;

means for comparing the present energy level determined to an average energy level of previously filtered waveforms by the same person, and for determining if the present energy level determined falls within a selected range based on the average energy level; and

means for counting the number of filtered waveforms that fall within the range within a selected time period, and if the number is within a selected amount, then for providing increasing the air pressure.

6. An apparatus for controlling sleep disorder breathing of a person, comprising in combination:

a source of air pressure;

an interface having one end connected to the source of air pressure and another end adapted to fit over the person'"'"'s nostril passages to supply air pressure from the source to the person'"'"'s nostril passages;

means for sensing the air pressure waveforms in the interface which occur as a result of the person'"'"'s breathing;

means for determining if the waveforms sensed have snoring characteristics associated with waveforms that occur during snoring;

means for increasing the air pressure if waveforms are sensed which have snoring characteristics and for gradually reducing the air pressure after a selected time period of waveforms with snoring characteristics cease to exist; and

wherein the means for determining if the waveforms sensed have snoring characteristics filters waveforms sensed and passes only those within a selected frequency range and further comprises;

means for determining a present energy level of each of the filtered waveforms;

means for comparing the present energy level determined to an average energy level of previously filtered waveforms by the same person and for determining if the present energy level determined falls within a selected range based on the average energy level; and

means for counting the number of filtered waveforms that fall within the range within a selected time period, and if the number is within a selected amount, then for providing a signal to increase the air pressure.

7. An apparatus for controlling sleep disorder breathing of a person, comprising in combination:

a source of air pressure;

an interface having one end connected to the source of air pressure and another end adapted to fit over the person'"'"'s nostril passages to supply air pressure from the source to the person'"'"'s nostril passages;

means for sensing the air pressure waveforms in the interface which occur as a result of the person'"'"'s breathing;

means for determining if the waveforms sensed have snoring characteristics associated with waveforms that occur during snoring;

means for increasing the air pressure if waveforms are sensed which have snoring characteristics and for gradually reducing the air pressure after a selected time period of waveforms with snoring characteristics cease to exist; and

wherein the means for determining if the waveforms sensed have snoring characteristics filters waveforms sensed and passes only those within a selected frequency range and further comprises;

means for determining a present area for each of the filtered waveforms;

means for determining a present duration for each of the filtered waveforms;

means for computing an average area based on areas computed for a selected number of previous filtered waveforms of the same person;

means for computing an average duration based on durations computed for a selected number of previous filtered waveforms of the same person; and

means for comparing the present area to the average area and comparing the present duration to the average duration to determine if the present area and the present duration fall within selected ranges of the average area and average duration.