Device and method for monitoring breathing during sleep, control of CPAP treatment, and preventing of apnea

• US 5,245,995 A
• Filed: 05/27/1992
• Issued: 09/21/1993
• Est. Priority Date: 06/26/1987
• Status: Expired due to Term

• Current Assignee: Resmed Limited (ResMed Incorporated)
• Original Assignee: Rescare Limited
• Inventors: Lynch, Christopher, Sullivan, Colin E.
• Primary Examiner(s): Fisher, J. Reed
• Assistant Examiner(s): Asher, Kimberly L.
• Application Number:
  US07/892,692
• Time in Patent Office: 482 Days
• Field of Search: 128/204.18, 128/204.21, 128/204.23, 128/207.13, 128/207.14, 128/207.18, 128/670, 128/671, 128/716, 128/719, 128/720, 128/724, 128/773, 128/205.2 5
• US Class Current: 128/204.23
• CPC Class Codes: A61B 5/097 Devices for facilitating collection of breath or for directing breath into or through measuring devices
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: A61B 7/003 Detecting lung or respiration noise
• 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 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 2016/0024 with an on-off output signal, e.g. from a switch
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• 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 2230/18 Rapid eye-movements [REM]
• CPC Class Codes: A61M 2230/205 partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/432 partial CO2 pressure (P-CO2)
• CPC Class Codes: A61M 2230/60 Muscle strain, i.e. measured on the user

Abstract

A CPAP apparatus including: a variable pressured air source and means to vary the air pressure delivered therefrom; a nose piece for sealed air communication with a patient'"'"'s respiratory system; an air communication line from the air source to the nose piece; a sound transducer adapted to be in sound communication with the patient'"'"'s respiratory system; and a feedback system controlling the output pressure of the air source in response to an output from the transducer so as to increase the output air pressure from said air source, in response to detection of sound indicative of snoring, in accordance with a predefined procedure. The sound transducer, in its most general form, comprises a pressure transducer which, in addition to detecting snoring sounds, can detect other respiratory parameters such as the rate of breathing, inhaled air flow volume, and inhaled air flow rate. Output air pressure from air source is increased in response to one or more of these parameters in accordance with a pre-defined procedure.

Claims

1. A method of CPAP therapy that substantially reduces the occurrence of obstructed breathing and obstructive apneas comprising the steps of:

providing nosepiece means for sealed air communication with a patient'"'"'s respiratory system;

providing said nosepiece with a straight section through which the patient'"'"'s respiratory air flows;

providing one or more sensors in pressure communication with the patient'"'"'s respiratory system;

providing pressure drop amplification means in the form of one or more flow restrictor(s) in said straight section of said nosepiece;

suitably positioning said one or more sensors on or connected to said nosepiece for measuring the pressure on either side of said flow restrictors;

continuously sensing the patient'"'"'s breathing patterns using said one or more sensors;

generating signals corresponding to said breathing patterns by means of said one or more sensors;

connecting a variable air pressure source to said patient nosepiece by a suitable length of flexible air tubing;

continuously delivering air to the patient from said variable air pressure source;

electronically analyzing said signals;

identifying characteristic abnormal breathing patterns indicative of obstructive breathing which may lead to apnea from said signals;

increasing the CPAP level delivered to the patient when abnormal breathing patterns are identified to substantially restore normal breathing and to substantially prevent the occurrence of apnea; and

reducing the CPAP level in the absence of breathing patterns indicative of obstructive breathing to a minimum level to maintain unobstructed breathing.

2. An apparatus comprising a CPAP device in combination wit a monitoring and control device, said apparatus comprising:

(a) a means for sealed air communication with a patient'"'"'s respiratory system;

(b) a variable air pressure source connected to said means for sealed air communication by a suitable length of air tubing;

(c) one or more sensors in communication with the patient'"'"'s respiratory system, said one or more sensors on or connected to said means for sealed air communication, and continuously sensing the patient'"'"'breathing patterns;

(d) means for generating signals corresponding to the patient'"'"'s breathing patterns in cooperation with said one or more sensors;

(e) means for electronically analyzing said signals and identifying characteristics of abnormal breathing patterns indicative of obstructed breathing which may lead to apnea from said signals;

(f) means for increasing the CPAP level delivered to the patient when abnormal breathing patterns are identified to substantially restore normal breathing and prevent the occurrence of apnea; and

(g) means for reducing the CPAP level in the absence of breathing patterns indicative of obstructed breathing to a minimum level to maintain unobstructed breathing.

3. The apparatus as in claim 2 wherein said one or more sensors include means for sensing snoring or a snoring pattern of the patient.

4. The apparatus as in claim 2 wherein said one or more sensors include means for sensing an exhaled air flow volume, an inhaled air flow volume, breathing rate, an exhaled air flow rate, or an inhaled air flow rate.

5. The apparatus as in claim 2 wherein the variable air pressure source delivers air at a pressure varying between a minimum operating pressure of about 3 cm H₂ O and a maximum operating pressure of about 20 cm H₂ O.

6. The apparatus as in claim 2 wherein the means for sealed air communication includes a mask and/or nasal prongs for delivery of air to the patient'"'"'s nasal passages.

7. The apparatus as in claim 2 wherein the variable air pressure source includes a variable speed air compressor.

8. The apparatus as in claim 2 wherein said one or more sensors comprises a microphone associated with the mask.