Breathable gas apparatus with humidifier

• US 9,227,035 B2
• Filed: 07/29/2014
• Issued: 01/05/2016
• Est. Priority Date: 06/20/2003
• Status: Active Grant

• Current Assignee: ResMed Pty Ltd. (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Crumblin, Geoffrey, Janiak, Michael Thomas, Kao, Dan, Kenyon, Barton John, Lithgow, Perry David, Primrose, Rohan Neil, Saada, Jim, Snow, John Michael, Trevor-Wilson, Duncan Lovel, Virr, Alexander, Yee, Arthur Kin-Wai
• Primary Examiner(s): YOUNG, RACHEL T
• Application Number:
  US14/445,190
• Publication Number:
  US 20140332003A1
• Time in Patent Office: 525 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0443 Modular apparatus
• CPC Class Codes: A61B 2560/0462 Apparatus with built-in sensors
• CPC Class Codes: A61B 2560/0475 Special features of memory means, e.g. removable memory cards
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 7/00 Instruments for auscultation
• 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 16/0003 Accessories therefor, e.g. sensors, vibrators, negative pressure
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0057 Pumps therefor
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/0816 Joints or connectors
• CPC Class Codes: A61M 16/0875 Connecting tubes
• CPC Class Codes: A61M 16/105 Filters A61M16/047, A61M16/22 take precedence; water traps A61M16/08
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 16/109 the humidifying liquid or the beneficial agent
• CPC Class Codes: A61M 16/16 Devices to humidify the respiration air A61M16/1045 takes precedence
• CPC Class Codes: A61M 16/162 Water-reservoir filling system, e.g. automatic
• CPC Class Codes: A61M 2205/0216 Materials providing elastic properties, e.g. for facilitating deformation and avoid breaking
• CPC Class Codes: A61M 2205/123 : with incorporated reservoirs
• CPC Class Codes: A61M 2205/14 : Detection of the presence or absence of a tube, a connector or a container in an apparatus
• CPC Class Codes: A61M 2205/3303 : Using a biosensor
• CPC Class Codes: A61M 2205/3306 : Optical measuring means
• CPC Class Codes: A61M 2205/3368 : Temperature
• CPC Class Codes: A61M 2205/36 : related to heating or cooling
• CPC Class Codes: A61M 2205/42 : Reducing noise
• CPC Class Codes: A61M 2205/50 : with microprocessors or computers
• CPC Class Codes: A61M 2205/502 : User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/52 : with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2205/6063 : Optical identification systems
• CPC Class Codes: A61M 2206/16 : Rotating swirling helical flow, e.g. by tangential inflows
• CPC Class Codes: A61M 2230/005 : Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/46 : Resistance or compliance of the lungs
• CPC Class Codes: A62B 9/003 : Means for influencing the temperature or humidity of the breathing gas
• CPC Class Codes: B01F 2101/55 : Mixing liquid air humidifiers with air
• CPC Class Codes: B01F 23/232 : using flow-mixing means for introducing the gases, e.g. baffles
• CPC Class Codes: B01F 23/237611 : Air
• CPC Class Codes: B29L 2031/753 : Medical equipment; Accessories therefor bloodbags, medical bags B29L2031/7148; artificial eyes B29L2011/0008
• CPC Class Codes: F04D 17/16 : for displacing without appreciable compression
• CPC Class Codes: F04D 25/0693 : Details or arrangements of the wiring
• CPC Class Codes: F04D 29/4206 : especially adapted for elastic fluid pumps
• CPC Class Codes: F04D 29/664 : by means of sound absorbing material

Abstract

A humidifier has a base unit with an engagement face that is configured to interface with a flow generator. The humidifier also has a tank configured to be removably received by the base unit and hold a volume of liquid. The tank has a side wall with an air inlet. The humidifier further has an air flow passage configured to receive an air connector of the flow generator at the engagement face of the base unit. The air flow passage is axially offset from a tank inlet. In addition, a cross-section of the airflow passage inlet and a cross-section of the tank air inlet are substantially perpendicular to a horizontal plane. In addition, a flexible face seal is positioned at an end of the air flow passage. An end of the face seal is configured to abut a side wall of the tank that includes the tank inlet when the tank is received in the base unit.

Claims

1. A humidifier comprising:

a base unit configured to attach to and detach from a flow generator, said base unit comprising;

an engagement face adapted to face a corresponding engagement face of the flow generator;

a plurality of tongues located on the engagement face that are adapted to move vertically and adapted to be resiliently urged downward to engage slots of the flow generator;

an air flow passage in communication with a circular aperture in the engagement face, both the circular aperture and the air flow passage being configured to receive an air connector of the flow generator;

a flexible face seal that defines a second aperture and is positioned at an end of the air flow passage, the flexible face seal having a peripheral portion that curves inwardly toward the second aperture;

an electrical connector, for engagement with a mating electrical connector on the flow generator, the electrical connector of the humidifier adapted to provide electrical power to the humidifier from the flow generator;

a circular pad positioned within a circular aperture in a lower surface of the base, the circular pad standing proud of the surrounding lower surface of the base and being resiliently biased upwardly through the circular aperture in the lower surface of the base;

a heating element to heat the circular pad;

a pivotable lid having a horizontal wall and a vertical wall extending downward from the horizontal wall;

a pipe extending from an upper surface of the horizontal wall of the lid and opening into an internal region of the base unit;

a lid seal attached to the lid, the lid seal having a sealing flange that extends downwardly from the lid and curves inwardly; and

a biased lid catch for securing the lid in a closed position; and

a tank adapted to attach to and detach from the base unit;

the tank comprising;

a cover;

a base to receive water therein;

a sealing gasket located between the cover and the base;

an air inlet passage extending from a side wall of the tank; and

an air outlet provided to a roof of the cover,

wherein;

the tank seats within the base unit so that a bottom of the tank is exposed to contact the circular pad when the tank is engaged with the base unit,

one or more liquid filling heights are indicated by filling level graduations marked on a wall of the tank,

the air inlet passage extends so that it opens in the interior of the tank at a point beyond, in the direction of air flow, a center of the air outlet,

the air inlet passage and the air outlet are oriented so that gas flows through the air inlet passage in a direction perpendicular to a direction in which the gas flows through the air outlet,

a vertical offset is provided between the air flow passage and the air inlet passage, with at least a portion of the air flow passage being lower than the air inlet passage in the normal orientation of the humidifier,

the peripheral portion of the face seal that curves inwardly is adapted to abut a portion of the tank side wall surrounding an opening in the tank side wall proximate an inlet end of the tank air inlet passage to form a sealed air path from the air flow passage of the base unit to the air inlet passage of the tank when the tank is received in the base unit,

the lid seal contacts the tank cover when the tank is received by the base unit and the lid is in the closed position so that the air outlet of the tank sealingly interfaces with the pipe,

a first end of the pipe passes through the horizontal wall of the lid and has a lower end that projects beyond the horizontal wall of the lid into an interior of the base unit to terminate at a rim so that a passage of the pipe opens into the interior of the base unit,

at least a portion of the lid seal surrounds the pipe, and

at least a portion of the pipe is at an acute angle to the horizontal.

2. The humidifier of claim 1, wherein the electrical connector is configured to provide data to the humidifier.

3. The humidifier of claim 1, wherein the base unit includes a variable power supply for the heating element for heating the circular pad.

4. The humidifier of claim 1, wherein, in at least two tilted positions of the tank, at least a portion of the air outlet is below the open end of the air inlet passage, such that water will flow through the air outlet before it will flow into the air inlet passage, and wherein in a normal operating position, when the air outlet is above the open end of the air inlet passage, water will not escape via the air inlet passage unless the tank has been over-filled.

5. The humidifier of claim 1, wherein the air flow passage is provided with a sealing device configured to sealingly receive the air connector of the flow generator.

6. The humidifier of claim 1, wherein an axis of the air inlet passage of the tank and an axis of a portion of the air flow passage configured to receive the air connector of the flow generator are vertically offset.

7. The humidifier of claim 1, wherein a second end of the pipe is configured to attach to a hose to supply humidified air to a patient.

8. The humidifier of claim 1, wherein the flexible face seal is formed from an elastomeric material.

9. The humidifier of claim 1, wherein the flexible face seal is structured so that the sealed air path between the air flow passage of the base unit and the air inlet passage of the tank is automatically formed when the tank is fully received in the base unit.

10. The humidifier of claim 1, wherein the second aperture at least partially defines an uppermost portion of the air flow passage.

11. A breathable gas supply apparatus for use in continuous positive airway pressure (CPAP) treatments, the apparatus comprising:

a humidifier according to claim 1; and

a flow generator that has an engagement face to face the engagement face of the humidifier, the flow generator comprising;

an external case of rigid plastic material comprising a top case and a bottom case, a lower edge of the top case being stepped and flanged to mate with a periphery of the bottom case;

an air connector projecting away from the engagement face of the flow generator and being in communication with the air flow passage of the humidifier;

a slot configured to receive a data card, the slot being provided in a wall of the external case;

an LCD screen visible through the top case by which a user can set the operating parameters of the apparatus;

a chassis positioned within the case, the chassis including a peripheral wall and a fan cavity;

a printed circuit board carrying electronic control components of the breathable gas apparatus, the printed circuit board being positioned in a space formed between the chassis and the top of the top case;

an air inlet formed in a wall of the external case;

an air inlet passage that communicates with the air inlet and opens to a space at least partly surrounding the fan cavity; and

an inlet tube configured to direct air from the space at least partly surrounding the fan cavity to an interior of the fan cavity;

a fan mounted in the fan cavity, the fan comprising;

a fan housing including a cover and a base;

a motor mounted within the fan housing;

a coaxial impeller mounted within the fan housing;

an air inlet in a floor of the base on an axis of the impeller; and

an air outlet, wherein

cavities in the cover and base of the fan housing form a volute which leads from the impeller to the fan air outlet, and

the fan air outlet is connected to the air connector via a coupling member.

12. The breathable gas apparatus of claim 11, further comprising a damping member positioned on a bottom surface of the bottom case.

13. A humidifier comprising:

a base unit with a) an engagement face that is configured to interface with a flow generator and b) a pivotable lid with a lid seal provided to an interior side of the lid;

a tank configured to a) be removably received by the base unit, b) be retained within the base unit by the base unit lid when the lid is in a closed position and c) hold liquid, the tank having a side wall with an air inlet;

an air flow passage configured to receive an air connector of the flow generator at the engagement face of the base unit, an inlet of the air flow passage being axially offset from the air inlet of the tank; and

a flexible face seal positioned at an end of the air flow passage, an end of the face seal being configured to abut the side wall of the tank that includes the tank air inlet when the tank is received in the base unit,

wherein the lid seal is configured to seal against a surface associated with the tank.

14. The humidifier of claim 13, wherein a cross-section of the airflow passage inlet and a cross-section of the tank air inlet are substantially perpendicular to a horizontal plane.

15. The humidifier of claim 13, wherein the air flow passage is vertically offset from the tank air inlet.

16. The humidifier of claim 15, wherein the air flow passage terminates at an aperture of the flexible face seal.

17. The humidifier of claim 16, wherein the aperture of the flexible face seal defines at least a portion of an uppermost portion of the air flow passage.

18. The humidifier of claim 17, wherein the aperture of the flexible face seal is entirely above a lowest portion of the air flow passage.

19. The humidifier of claim 13, wherein the tank includes a cover, a base, and a sealing gasket between the cover and the base;

and an air outlet is located proximate a roof of the cover.

20. The humidifier of claim 19, wherein the tank air outlet and the tank air inlet are oriented so that gas enters the tank in a direction perpendicular to a direction in which the gas exits the tank.

21. The humidifier of claim 13, wherein, in a tilted position of the tank, at least a portion of an air outlet of the tank is below the tank air inlet, such that liquid will flow through the air outlet before it will flow through the tank air inlet, and wherein when the air outlet is above the tank air inlet, water will not escape via the tank air inlet unless the tank has been over-filled.

22. The humidifier of claim 13, wherein the end of the face seal that is configured to abut the side wall of the tank curves inwardly toward an aperture defined by the face seal.

23. The humidifier of claim 22, wherein the end of the face seal is configured to abut a portion of the tank side wall surrounding the tank air inlet to form a sealed air path from the air flow passage of the base unit to the tank air inlet.

24. The humidifier of claim 23, wherein the sealed air path between the air flow passage of the base unit and the tank air inlet is automatically formed when the tank is received in the base unit.

25. A gas supply system comprising:

a humidifier according to claim 13; and

a flow generator releasably connected to the humidifier, the flow generator comprising;

an external case comprising a top case and a bottom case;

a chassis formed with a peripheral wall and including a fan cavity; and

a fan mounted in the fan cavity and housed by a fan housing;

a motor mounted within the fan housing; and

a coaxial impeller mounted within the fan housing.

26. The humidifier of claim 13, wherein the tank is configured so that when the tank is removed from the base unit, a seal between the flexible face seal and the side wall of the tank is broken.

27. A method of humidifying pressurized gas comprising:

receiving pressurized gas from ambient or an external source in an air flow passage positioned at a first position within a base unit of a humidifier, the first position being proximate an engagement face of the base unit that is configured to interface with a flow generator;

directing the received pressurized gas from the first position within the base unit to an air inlet passage of a tank at a second position that is axially offset from the air flow passage at the first position, the tank being contained within the base unit and holding liquid;

forming a seal between the air flow passage and the air inlet passage of the tank at the second position by pressing the tank against a face seal positioned at an end of the air flow passage so that an end of the face seal abuts a surface of the tank surrounding an inlet opening of the air inlet passage; and

exposing the pressurized gas to the liquid in the tank to humidify the pressurized gas,

wherein gas at the first position flows in a first direction and gas at the second position flows in a second direction,

the first and second directions are substantially parallel to a horizontal plane,

the first and second positions are vertically offset from each other, and

the tank is retained within the base unit by a lid pivotably attached to the base unit when the lid is in a closed position.

28. The method of claim 27, further comprising inhibiting the liquid in the tank from reaching the first position when the humidifier is tilted from a normal upright operating position.

29. The method of claim 27, wherein when the lid is in the closed position and the tank is received within the base unit, the lid engages a top portion of the tank to form a sealed gas passage with the tank, the sealed gas passage conveying humidified gas from within the tank to a location outside of the base unit.

30. The method of claim 27, wherein the seal between the air flow passage and the air inlet passage at the second position is automatically formed by positioning the tank within the base unit of the humidifier.