Systems, methods, and/or apparatuses for non-invasive monitoring of respiratory parameters in sleep disordered breathing

• US 8,646,447 B2
• Filed: 11/13/2007
• Issued: 02/11/2014
• Est. Priority Date: 11/13/2006
• Status: Active Grant

• Current Assignee: ResMed Pty Ltd. (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Martin, Dion Charles Chewe, Oates, John David
• Primary Examiner(s): Ginsberg, Oren
• Assistant Examiner(s): GANESAN, SUNDHARA M
• Application Number:
  US12/514,696
• Publication Number:
  US 20100016694A1
• Time in Patent Office: 2,282 Days
• Field of Search: 128/204.23, 128/204.18, 128/204.26, 600/323, 600/509, 600/538, 600/534, 600/484
• US Class Current: 128/204.23
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/4809 Sleep detection, i.e. determining whether a subject is asleep or not
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/4848 Monitoring or testing the effects of treatment, e.g. of medication
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0057 Pumps therefor
• 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 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2230/005 Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/202 partial carbon oxide pressure, e.g. partial dioxide pressure (P-CO2)
• CPC Class Codes: A61M 2230/205 partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/42 Rate

Abstract

In certain example embodiments, an air delivery system includes a controllable flow generator operable to generate a supply of pressurized breathable gas to be provided to a patient for treatment and a pulse oximeter. In certain example embodiments, the pulse oximeter is configured to determine, for example, a measure of patient effort during a treatment period and provide a patient effort signal for input to control operation of the flow generator. Oximeter plethysmogram data may be used, for example, to determine estimated breath phase; sleep structure information; autonomic improvement in response to therapy; information relating to relative breathing effort, breathing frequency, and/or breathing phase; vasoconstrictive response, etc. Such data may be useful in diagnostic systems.

Claims

1. An air delivery system, comprising:

a controllable flow generator operable to generate a supply of pressurized breathable gas to be provided to a patient for treatment;

a pulse oximeter configured to generate, during a treatment period, a patient effort signal for input to control operation of the flow generator; and

a controller configured to derive an estimated breath phase of the patient independent of measured flow, based at least in part on the patient effort signal, wherein the controller comprises one or more predictive breath-phase algorithms to improve synchrony based at least in part on the patient effort signal and/or the estimated breath phase and the controller is configured to improve synchrony when inspiratory flow is not an accurate indicator of commencement of inspiratory effort.

2. An air delivery system, comprising:

a controllable flow generator operable to generate a supply of pressurized breathable gas to be provided to a patient for treatment;

a pulse oximeter configured to generate, during a treatment period, a patient effort signal for input to control operation of the flow generator; and

a controller configured to derive an estimated breath phase of the patient independent of measured flow, based at least in part on the patient effort signal,

wherein the pulse oximeter is configured to pre-configure and/or auto-configure one or more of backup rate, minimum machine timing, and maximum inspiratory timing prior to therapy.

3. A method for treating sleep disordered breathing, said method comprising:

deriving a pulse oximeter signal from a patient;

processing the pulse oximeter signal to generate a patient effort signal indicative of respiratory rate;

deriving an estimated breath phase of the patient independent of measured flow based at least in part on the patient effort signal;

analyzing the patient effort signal and/or the estimated breath phase with predictive breath-phase algorithms to improve synchrony; and

improving the synchrony when inspiratory flow is not an accurate indicator of the start of inspiratory effort.

4. A method for treating sleep disordered breathing, said method comprising:

deriving a pulse oximeter signal from a patient;

processing the pulse oximeter signal to generate a patient effort signal indicative of respiratory rate;

deriving an estimated breath phase of the patient independent of measured flow based at least in part on the patient effort signal; and

pre-configuring and/or auto-configuring one or more of backup rate, minimum machine timing, and maximum inspiratory timing via a pulse oximeter probe prior to therapy.

5. A respiratory effort monitoring apparatus, comprising:

a pulse oximeter configured to derive a pulse oximeter signal; and

a signal processor configured to receive the pulse oximeter signal and generate a patient effort signal indicative of respiratory rate;

wherein the signal processor is configured to derive an estimated breath phase of the patient independent of measured flow based at least in part on the patient effort signal, and the signal processor is configured to improve synchrony when inspiratory flow is not an accurate indicator of commencement of inspiratory effort.