BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention, and together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention.
FIG. 1 is a perspective, diagrammatic view of a chamber-to-reservoir vented humidification system constructed in accordance with the principles of the present invention;
FIG. 2 is an exploded, perspective partial view of the bottle, vented cap, supply and vent lines, and straw used in the system of FIG. 1;
FIG. 3 is a cross-sectional view of the vented cap used in the system of FIG. 1;
FIG. 4 is an enlarged view of the area within line 4 of FIG. 3;
FIG. 5 is a view taken along line 5-5 of FIG. 4; and
FIG. 6 is an enlarged view of the area within line 6 of FIG. 3.
DETAILED DESCRIPTION OF THE DRAWINGS
With reference to FIG. 1, there is shown an exemplary chamber-to-reservoir vented humidification system 10 constructed in accordance with the principles of the present invention. To that end, system 10 includes a humidification chamber 12 mounted in heat transfer relationship atop a heater base 14, and a water reservoir bottle 16 held, such as by rack 18, so as to be inverted and generally elevated relative to chamber 12. Chamber 12 has a top wall 20 and a side wall 21, which may be a single plastic housing section, and a bottom wall 22 joined to side wall 21. Communicating through top wall 20 is a gas or air inlet 24, which may be coupled to an air hose 25 (shown in dashed line) to receive breathable gas into chamber 12. Breathable gas passes out of chamber 12 via gas or air outlet 26, also communicating through top wall 20. Gas outlet 26 may be coupled via an air hose 27 (shown in dashed line) to a patient (not shown) to provide breathable gas that has picked up moisture and possibly heat as it traveled through chamber 12 as is conventional. Also communicating through top wall 20 of chamber 12 is a water inlet 30 which couples into chamber 12 via float valve 32. Chamber 12 further includes a vent 34 communicating through top wall 20. The foregoing construction of chamber 12 may be as described in aforementioned U.S. Pat. Nos. 5,943,473 and 6,988,497 or aforementioned concurrently filed U.S. patent application entitled Float for Humidification Chamber, Attorney Docket No. MDXCP-30US.
Bottle 16 is defined by a generally rigid or semi-rigid container body 40 (as opposed to the flexible walls of a bag) and may further be rectangular in cross section as seen in FIG. 1. With further reference to FIGS. 2 and 3, extending from body 40 is a tubular neck 42 terminating at peripheral edge 43 to define opening 44 of bottle 16. Neck 42 has external threads 45. Bottle 16 may include a flat or planar annular surface 46 adjacent base 47 of neck 42. Bottle 16 is closed by vented cap 50 which is molded plastic having a top wall 52 and a depending skirt 54. Skirt 54 has internal threads 55 to threadingly engage threads 45 of neck 42 to secure cap 50 to bottle 16. A gasket 56 may be included in cap 50 adjacent the underside of top wall 52 to seal against edge 43 of neck 42 (FIG. 3). Skirt 54 may terminate at its free end 57 in a flat or planar annular surface 58 which mates up against annular surface 46 of bottle 16 to define a further or secondary seal thereat (FIGS. 3 and 6).
Cap 50 is advantageously a plastic molded component which includes molded into cap top wall 52 a water port 60 opening into area 62 of cap 50 within skirt 54 and below top wall 52. Uninterrupted supply line or tubing 64 is attached at one end to water port 60 (FIG. 3) and at its other end to water inlet 30 of chamber 12 (FIG. 1) so as to couple water 66 from within bottle 16 into chamber 12 via float valve 32. Cap 50 also includes a vent port 70, which in the embodiment shown, is defined by valve housing 72 and valve retainer 74. As seen in greater detail in FIGS. 4 and 5, valve housing 72 is integrally molded in the top wall 52 of cap 50 so as to define (a) valve space 75 opening out of top wall 52 at opening 76 and (b) outlet orifice 78 to which is coupled tubing or straw 80 which extends to an open end 81. Straw 80 may be rigid, semi-rigid or flexible, provided it has enough firmness to extend upwardly when cap 50 is held upside down such as when bottle 16 is inverted as seen in FIG. 1 so as to space open end 81 of straw 80 from cap 50. Housing 72 extends from the underside of cap top wall 52 within area 62 and, advantageously, is completely within area 62 such that outlet orifice 78 does not extend beyond plane 82 defined by annular surface 58 of skirt 54.
A check valve, such as a duckbill valve 84, is fitted into valve space 75 through opening 76. Valve retainer 74 is secured to top wall 52 at opening 76, such as by adhesive or ultrasonic welding, so as to secure valve 84 therein in communication with valve port 70. Valve retainer 74 has an inlet orifice 86 at one end spaced from the cap top wall 52, and may include at the other end an annular edge 87 to form a seal with opening 76 of cap top wall 52. Uninterrupted vent line or tubing 90 is attached at one end to inlet orifice 86 of vent port 70 (FIG. 3) and at its other end to vent 34 of chamber 12 (FIG. 1) so as to vent chamber 12 into reservoir bottle 16. Straw 80 extends into bottle 16 so as to space open end 81 from cap 50 and, in the embodiment shown herein, spaced from valve 84 and beyond plane 82 of cap 50, so as to reduce the head of water imposed on valve 84. Straw 80 may extend into bottle 16 so that its open end 81 is above the level of water 66 therein when bottle 16 is inverted as seen in FIG. 1. It will be appreciated, however, that if bottle 16 is full, open end 81 may be at or near (and possibly slightly below) the level of water 66 until after some of water 66 has emptied out therefrom. Further, straw 80 could be flexible such that open end 81 tends to move with the water level while being just below, at, or just above the water level.
Valve 84 advantageously is a duckbill valve which is characterized by a pair of opposed, canted walls 92 that join at a slit 93, and has a base flange 94 to support it at opening 76 of cap 50 (FIGS. 4 and 5). Valve 84 is advantageously normally closed and oriented so as to open in response to a greater pressure at the inlet orifice 86 relative to the outlet orifice 78 (which could be due to water 66 evacuating the bottle 16 through the water port 60 and/or a positive pressure pulse from within the chamber 12), but not in response to either no pressure differential or a greater pressure at the outlet orifice 78 relative to the inlet orifice 86 (such as might occur during a negative pressure pulse within the chamber 12). The check valve 84 can also serve to prevent accidental evacuation of water 66 through the vent port 70.
In use, vented cap 50 is screwed onto bottle neck 42, with straw 80 extending into bottle 16. Supply line 64 and vent line 90 are coupled at one end to water port 60 and vent port 70 of cap 50 and at the other end to water inlet 30 and vent 34 of chamber 12, respectively. Bottle 16 is inverted and held generally elevated relative to chamber 12 such that the level of water 66 in bottle 16 is above the level of water 66 in chamber 12. The patient (not shown) is ventilated or otherwise assisted in breathing with breathable gas passed through chamber 12 to pick up moisture and heat from water 66 within chamber 12. Bottle 16 empties of water 66 without difficulty via vent line 90 and without adversely affecting operation of system 10 during positive and/or negative pressure pulses incurring during inspiratory and exhalation pulses within chamber 12.
By virtue of the foregoing, there is thus provided a venting system by which to utilize an elevated bottle as the water reservoir in a chamber-to-reservoir vented humidification system, and which is believed to overcome the limitations and obstacles of existing bottle-based and flexible bag-based chamber-to-reservoir vented humidification systems.
While the present invention has been illustrated by the description of an embodiment thereof, and while the embodiment has been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example, while valve 84 is shown as communicating with vent port 70 by being mounted to cap 50, a check valve could additionally or alternatively be mounted to open end 81 of straw 80 so as to communicate with vent port 70 via straw 80. Further, valve housing 72 could be located so as to position valve 84 above or astride top wall 52 and could further define the inlet orifice, with the valve retainer being positioned within cap 50 and defining the outlet orifice. Also, bottle 16 could be suspended from a pole or the like. Still further, chamber 12 might not be heated or could be of a different construction and mounted within a heater mechanism. The invention in its broader aspects is, therefore, not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept.
Patent Application
20080054497
