Computer Controlled Cpap System with Snore Detection

• US 20080308105A1
• Filed: 01/04/2007
• Published: 12/18/2008
• Est. Priority Date: 01/06/2006
• Status: Active Grant

• Current Assignee: ResMed Pty Ltd. (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Farrugia, Steven Paul, Somaiya, Chinmayee, Alder, Matthew, Thomsen, Kristian
• Granted Patent: US 8,365,729 B2
• Time in Patent Office: Days
• 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 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/682 Mouth, e.g., oral cavity; tongue; Lips; Teeth
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 7/003 Detecting lung or respiration noise
• CPC Class Codes: A61M 16/00 Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes stimulating the respiratory movement by mechanical, pneumatic or electrical means, iron lungs combined with gas breathing means A61H31/00
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• 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 16/0666 Nasal cannulas or tubing devices for improving normal breathing through the nose A61F5/08; nose filters A62B23/06; outside holding devices A61M25/02
• CPC Class Codes: A61M 2205/3375 Acoustical, e.g. ultrasonic, measuring means

Abstract

A CPAP apparatus is provided that determines the presence of a snore by the simplified method of using filtered expiratory noise as the measure of intrinsic device noise and comparing that to filtered inspiratory noise. The filtering time constants for inspiratory and expiratory noise are adjusted such that treatment pressure does not cause false snore detection.

Claims

1. A CPAP device having a sensor for detecting snoring sounds, comprising a processor controlled program for executing the steps of:

measuring sounds during inspiration and determining an inspiratory value during inspiration filtered with a time constant Tinsp,

measuring sounds during expiration and determining an expiratory value during expiration filtered with a time constant Texp, wherein Tinsp is adjusted with respect to Texp such that false snore is not detected due to changes in treatment pressure

providing a signal indicative of a snore if at a time of entry to expiration, the difference between the inspiratory value and the expiratory value exceeds the ratio of the expiratory value to a predetermined threshold factor,

filtering the said signal indicative of snore over multiple breaths and reporting said filtered value as an average snore value.

2. A CPAP device according to claim 1 wherein the sensor is pressure sensor.

3. A CPAP device according to claim 1 wherein the sensor is a microphone.

4. A CPAP device having a sensor for detecting snoring sounds, comprising a processor controlled program for executing the steps of:

measuring sounds during inspiration and determining an inspiratory value during inspiration filtered with a time constant Tinsp,

measuring sounds during expiration and determining an expiratory value during expiration filtered with a time constant Texp, wherein Tinsp>

Texp,

providing a signal indicative of a snore if at a time of entry to expiration, the difference between the inspiratory value and the expiratory value exceeds the ratio of the expiratory value to a predetermined threshold factor,

filtering the said signal indicative of snore over multiple breaths and reporting said filtered value as an average snore value.