Ventilation mask with heat and moisture exchange device
In accordance with the present invention, there is provided a mask, such as a nasal pillows mask, for achieving positive pressure mechanical ventilation (inclusive of CPAP, ventilator support, critical care ventilation, emergency applications). The mask of the present invention includes a piloted exhalation valve that is used to achieve the target pressures/flows to the patient. The pilot for the valve may be pneumatic and driven from the gas supply tubing from the ventilator. The mask of the present invention further includes a heat and moisture exchange (HME) device which is directly integrated into the housing or cushion thereof (thus residing in extremely close proximity to the patient's nostrils), and is further uniquely configured to induce a flow pattern between it and the cushion which maximizes the transmission of heat and moisture to air which is inhaled by and exhaled from the patient through the mask.
1. A nasal pillows mask, comprising:
a cushion defining an internal fluid chamber, a pair of pillow portions defining open interiors therein which each fluidly communicate with the fluid chamber, and at least one gas delivery lumen which fluidly communicates with the fluid chamber, the at least one gas delivery lumen having a fluid inlet end proximate the fluid chamber; and
a heat and moisture exchange device disposed within the fluid chamber of the cushion proximate the open interiors of the pillow portions thereof, wherein the heat and moisture exchange device is configured to at least partially segregate the open interiors of the pillow portions from the fluid chamber and further configured so as not to cover the fluid inlet end of the at least one gas delivery lumen and to extend at least partially between the at least one gas delivery lumen and the open interiors of the pillow portions.
2. The nasal pillows mask of claim 1 further comprising:
a valve pilot lumen defined by the cushion; and
an exhalation valve cooperatively engaged to the cushion in a manner wherein the valve pilot lumen is fluidly coupled thereto, the exhalation valve being fluidly coupled to the fluid chamber;
the exhalation valve being piloted, and selectively movable between a closed position wherein fluid flow between the fluid chamber and ambient air is at least partially obstructed thereby, and an open position wherein at least a portion of the fluid chamber is vented to ambient air.
3. The nasal pillows mask of claim 2 wherein the heat and moisture exchange device is permanently attached to the exhalation valve.
4. The nasal pillows mask of claim 3 wherein the heat and moisture exchange device has a generally frusto-conical configuration.
5. The nasal pillows mask of claim 1 wherein the heat and moisture exchange device is further configured to fully segregate the pillow portions from the fluid chamber.
6. The nasal pillows mask of claim 1 wherein:
the cushion defines first and second gas delivery lumens which each fluidly communicate with the fluid chamber, the first and second gas delivery lumens each having a fluid inlet end proximate the fluid chamber; and
the heat and moisture exchange device is further configured so as not to cover the fluid inlet end of either of the first and second gas delivery lumens.
7. The nasal pillows mask of claim 1 wherein:
the cushion further defines a pressure sensing lumen which fluidly communicates with the fluid chamber; and
the heat and moisture exchange device is further configured so as not to cover the pressure sensing lumen.
8. The nasal pillows mask of claim 1 wherein:
the fluid chamber is formed to be of a prescribed shape and internal volume; and
the heat and moisture exchange device is configured relative to the shape and internal volume of the fluid chamber such that fluid flowing into the fluid chamber from the gas delivery lumen has a prescribed pattern of turbulence imparted thereto.
9. The nasal pillows mask of claim 1 wherein the heat and moisture exchange device has a multi-layer construction.
10. The nasal pillows mask of claim 9 wherein the heat and moisture exchange device comprises:
a high density layer;
a low density layer; and
a medium density layer captured between the high and low density layers;
the heat and moisture exchange device being oriented within the fluid chamber such that the high density layer is disposed closest to the pillow portions of the cushion.
11. A nasal pillows mask, comprising:
a cushion defining at least one flow passage, wherein the cushion defines first and second gas delivery lumens which each fluidly communicate with the flow passage, the first and second gas delivery lumens each having a fluid inlet end proximate the flow passage, wherein the cushion further defines at least one delivery section that channels fluid flowing into the flow passage from the first and second gas delivery lumens into a nose of a patient; and
a heat and moisture exchange device disposed within the flow passage;
wherein the heat and moisture exchange device is configured relative to the flow passage such that fluid flowing into the flow passage has a prescribed pattern of turbulence imparted thereto by the cushion and the heat and moisture exchange device and further configured so as not to cover the fluid inlet end of either of the first and second gas delivery lumens and to extend at least partially between the first and second gas delivery lumens and the at least one delivery section.
12. The nasal pillows mask of claim 11 further comprising:
an exhalation valve cooperatively engaged to the cushion and fluidly coupled to the flow passage;
the exhalation valve being selectively movable between a closed position wherein fluid flow between the flow passage and ambient air is at least partially obstructed thereby, and an open position wherein at least a portion of the flow passage is vented to ambient air.
13. The nasal pillows mask of claim 12 wherein the heat and moisture exchange device is permanently attached to the exhalation valve.
14. The nasal pillows mask of claim 11 wherein:
the cushion further defines a pressure sensing lumen which fluidly communicates with the flow passage; and
the heat and moisture exchange device is further configured so as not to cover the pressure sensing lumen.
15. The nasal pillows mask of claim 11 wherein the heat and moisture exchange device has a multi-layer construction.
16. The nasal pillows mask of claim 15 wherein the heat and moisture exchange device comprises:
a high density layer;
a low density layer; and
a medium density layer captured between the high and low density layers.