CPAP RESPIRATORY APPARATUS

• US 20020096173A1
• Filed: 09/06/1995
• Published: 07/25/2002
• Est. Priority Date: 12/20/1991
• Status: Abandoned Application

• Current Assignee: Resmed Limited (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: BERTHON-JONES, MICHAEL, CALLUAUD, MICHEL, SULLIVAN, COLIN E., LYNCH, CHRISTOPHER E.
• Application Number:
  US08/524,148
• Publication Number:
  US 20020096173A1
• Time in Patent Office: Days
• 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 16/022 Control means therefor
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0616 with face sealing means comprising a flap or membrane projecting inwards, such that sealing increases with increasing inhalation gas pressure
• CPC Class Codes: A61M 16/0633 with forehead support
• CPC Class Codes: A61M 16/0677 Gas-saving devices therefor
• CPC Class Codes: A61M 16/0683 Holding devices therefor
• CPC Class Codes: A61M 16/08 Bellows; Connecting tubes having means for taking samples G01N1/22; Water traps; Patient circuits
• CPC Class Codes: A61M 16/0825 with ball-sockets
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 16/0858 Pressure sampling ports
• CPC Class Codes: A61M 16/1045 Devices for humidifying or heating the inspired gas by using recovered moisture or heat from the expired gas
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2210/0618 Nose

Abstract

The present invention discloses both a method of operating CPAP apparatus, and the apparatus itself in which a breathable gas delivery device, or mask (1), is connected to a gas supply pump (14) via a conduit which includes a restriction to gas flow such as a small bore portion (3). A pressure transducer (11) is used to sense the gas pressure at the patient'"'"'s nose and the transducer output is used to servo-control the pump (14) to maintian the sensed pressure substantially constant.

Claims

1. A CPAP respiratory apparatus comprising a breathable gas delivery device adapted to deliver breathable gas to inlet the of a patient'"'"'s respiratory system, a breathable gas supply means having an outlet and arranged to supply breathable gas to said outlet at a pressure above atmospheric pressure, and a flexible conduit having an internal bore and being connected between outlet and said gas delivery device wherein a pressure transducer is connected to said device to sense the pressure at said respiratory system inlet, and a servo-controller is connected to both said gas supply means and said pressure transducer to adjust the operation of said gas supply means to maintain the pressure at said respiratory system inlet substantially constant.

2. Apparatus as claim 1, wherein said gas delivery device comprises a nose mask.

3. Apparatus as claimed in claim 1, wherein said flexible conduit includes a pressure drop inducing means.

4. Apparatus as claimed in claim 3, wherein said pressure drop inducing means comprises at least that portion of said conduit closest to said gas delivery device which has an internal bore which is relatively small compared with the remainder of said conduit.

5. Apparatus as claimed in claim 4, wherein said small bore portion is joined to the remainder of said conduit by a swivel joint.

6. Apparatus as claimed in claim 4, wherein said small bore portion has a flattened non-circular profile.

7. Apparatus as claimed in claim 4, wherein said small bore portion is arranged to pass between the eyes of said patient.

8. Apparatus as claimed in claim 6, wherein said small bore portion is bifurcated and includes two parts which each extend from behind the head of said patient past the corresponding cheek to said gas delivery device.

9. Apparatus as claimed in claim 4, wherein said small bore portion includes a pressure port and/or a transducer cable.

10. Apparatus as claimed in claim 3, wherein said pressure drop inducing means is selected from the class consisting of a bend in said conduit, a swivel joint in said conduit, a pressure transducer, a humidifier, a filter, baffle means, a flow measuring orifice and an adapter to connect portions of said conduit of different effective internal diameters.

11. A method of operating a breathable gas supply means of a CPAP respiratory apparatus comprising a breathable gas delivery device adapted to deliver breathable gas to the inlet of a patient'"'"'s respiratory system and connected by a flexible conduit to an outlet of said gas supply means to receive breathable gas therefrom at a pressure above atmospheric pressure, said method comprising the steps of sensing the pressure supplied to said respiratory system inlet by said gas delivery device, and using the sensed pressure to servo-control said gas supply means to maintain pressure at said respiratory system inlet substantially constant.

12. A method as claimed in claim 11, wherein said gas delivery device comprises a nose mask having a nose receiving cavity, and said sensed pressure is the pressure within said cavity.

13. A method as claimed in claim 11, including the step of locating a pressure drop inducing means in said conduit.