Determination of mask fitting pressure and correct mask fit

• US 7,100,608 B2
• Filed: 01/04/2002
• Issued: 09/05/2006
• Est. Priority Date: 12/21/1998
• Status: Expired due to Term

• Current Assignee: ResMed Pty Ltd. (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Brewer, Gregory Newton, Somaiya, Chinmayee, Colla, Gregory Alan, Farrugia, Steven Paul
• Primary Examiner(s): Bennett, Henry
• Assistant Examiner(s): Ragonese, Andrea M.
• Application Number:
  US10/035,199
• Publication Number:
  US 20020056452A1
• Time in Patent Office: 1,705 Days
• Field of Search: 128/204.18, 128/204.21, 128/204.23, 128/204.22
• US Class Current: 128/204.23
• 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 16/0069 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 16/0605 Means for improving the adaptation of the mask to the patient
• 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 2205/13 with means for the detection of operative contact with patient, e.g. lip sensor
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A62B 27/00 Methods or devices for testing respiratory or breathing apparatus for high altitudesapparatus for testing gastightness in general G01M

Abstract

A method for determining a mask-fit test pressure to be applied to a wearer'"'"'s mask by ventilatory assistance apparatus includes adaptively determining the mask-fit pressure from prior use.

Claims

1. A method for determining a mask-fit test pressure to be applied to a wearer'"'"'s mask by ventilatory assistance apparatus, wherein the mask-fit pressure is adaptively dependent on a prior pressure treatment session of the wearer, said mask-fit test pressure not being significantly different than pressures encountered in normal use of the wearer during the prior treatment session, said mask-fit pressure being greater than a minimum pressure and less than a maximum pressure encountered during the prior treatment session.

2. The method of claim 1, wherein the mask-fit test pressure is determined based on a prior use by comparing leak flow to a threshold leak flow value.

3. The method of claim 2, wherein leak flow is determined over a predetermined time period.

4. The method of claim 3, wherein the leak flow is determined based on a time constant of about 10 seconds.

5. The method of claim 1, wherein the method is practiced with a CPAP device having two functional modes.

6. The method of claim 5, wherein the first mode is a manual mode and the second mode is an automatic titration mode, and wherein:

in the manual mode, the test-fit pressure is the current set treatment pressure, and

in the automatic titration mode, the test-fit pressure is a percentile pressure of the prior treatment session.

7. The method of claim 6, wherein the test-fit pressure is a base pressure if data from said prior treatment session is not available.

8. The method of claim 1, wherein determining the mask-fit pressure includes sampling of pressure signals in a gas supply assembly associated with the mask.

9. The method of claim 8, wherein the sampling of pressure signals occurs in a delivery tube of the gas supply assembly.

10. The method of claim 8, wherein the sampling of pressure signals occurs at predetermined intervals.

11. The method of claim 10, wherein sampling occurs at about 20 millisecond intervals.

12. The method of claim 8, wherein the sampling of the pressure signals includes determining a flow of gas in the mask and generating a delivery pressure signal.

13. The method of claim 1, further comprising varying at least one setting relating to test pressure intervals, test pressure period, and determined test pressure.

14. The method of claim 1, wherein pressure data from said prior treatment session is available if the prior treatment pressure occurred for at least a predetermined time interval.

15. The method of claim 14, wherein the predetermined time interval is about 3 hours.

16. A method for determining a mask-fit test pressure to be applied to a wearer'"'"'s face by ventilatory assistance apparatus, wherein:

the mask-fit pressure is adaptively dependent on a prior pressure treatment session of the wearer,

determining the mask-fit pressure includes sampling of pressure signals in a gas supply assembly associated with the mask, and

the sampling of pressure signals occurs in a blower of the gas supply assembly.

17. A method for determining a mask-fit test pressure to be applied to a wearer'"'"'s face by ventilatory assistance apparatus, wherein:

the mask-fit pressure is adaptively dependent on a prior pressure treatment session of the wearer,

determining the mask-fit pressure includes sampling of pressure signals in a gas supply assembly associated with the mask, and

determining the mask-fit pressure also includes processing the sampled pressure signals and producing a control signal based on the processed signals, wherein the control signal is provided to a motor to provide a determined treatment pressure.

18. The method of claim 17, further comprising comparing a signal representative of actual delivery pressure with the control signal.

19. A method for determining mask-fit pressure to be applied to a wearer'"'"'s mask by a continuous positive airway pressure apparatus having an automatic titration mode that delivers a flow of pressurized breathable gas to the wearer'"'"'s mask, said method comprising:

measuring by a pressure sensor the mask pressure used by the wearer during a treatment session; and

determining a mask fit test pressure from the pressures used by the wearer during the treatment session, said mask-fit test pressure not being significantly different than pressures encountered in normal use of the wearer during the treatment session.