Ventilator airway fluid collection system

Abstract: The ventilator airway fluid collection system permits the maintenance of PEEP in a patient breathing circuit when a fluid collector vial (22) is removed. A fluid collection vial (22) is connected to the airway from which fluid is to be collected by connection to an arm of a tee connector (12), and a disc assembly is provided in the arm of the tee connector (12) that closes the opening to the vial (22) when the vial (22) is removed. The disc assembly includes a first disc (26) fixedly mounted in the connector arm, and a second disc (30) rotatably mounted to first disc (26). The first disc (26) includes at least one aperture (28), and the second disc (30) includes at least one corresponding aperture (32). The second, rotatable disc (30) includes at least one tab (36) for indexing the second disc's aperture (32) to open the passageway to the vial (22) when the vial (22) is attached, and to close the passageway when the vial (22) is removed.

Description: BACKGROUND OF THE INVENTION Field of the Invention: This invention relates generally to breathing ventilators, and more particularly concerns a ventilator airway fluid collection system including a fluid collector vial that is connected to an airway of the ventilator, and which allows PEEP to be maintained in a patient breathing circuit when the fluid collector vial is removed for emptying. Description of Related Art: Breathing ventilator systems conventionally provide a breathing gas at elevated pressure levels. Pressure support is also known in the art by other names, e.g. inspiratory assist, pressure assist, or inspiratory pressure assist. Pressure in a ventilator airway is commonly maintained at PEEP (Patient End Expiratory Pressure, a baseline pressure value) to assist patient breathing efforts. Breathing gas is also often supplemented with a higher proportion of oxygen than is found in the ambient atmosphere, and is commonly humidified. Consequently, moisture regularly condenses in a ventilator airway, and one or more fluid collector vials can be placed in strategic locations in the airway to collect such fluid condensate. A common problem with such fluid collection systems is that PEEP can be lost to the patient when the airway is opened to atmospheric pressure when such collector vials are removed to dispose of collected fluid. Fluid can also be sprayed out of the airway if the ventilator is operating when the fluid collection vial is removed, which can be unpleasant and unhygienic. One known solution to this problem has been to provide spring loaded seals which close off the fluid collection opening in,the airway when a collection vial is removed. However,' such spring loaded seals can be expensive, difficult to clean, and can fail due to blockage of the seal, cracking of the seal, failure of the spring, and similar problems. Another solution is described in EP-A-0,460,731 in which there is presented a water trap for a respiratory airline comprising a top and base the respective openings of which mate when they are releasably connected eg., by a bayonet-joint. The opening of the top is partially spanned centrally by a disc, leaving an annular pathway for water around the periphery of the disc. A resilient annular sealing member connected at its outer periphery to the top makes sealing contact with the disc when the base is removed, but when the base is connected to the top the upper periphery of the base raises the sealing member to allow water to fall from the top and be collected in the base. In a different field it is also known from US-A-4,538,653 to provide a closure and valve for liquid containers comprising a valve body and a plug body insertable and rotatable therein. Discs are seated within the valve body which have off-center holes which are aligned or misaligned by stems depending from the bottom edge of the plug and which register with notches in the edges of the disc. A non-rotating disc having corresponding off-center holes is placed between the rotating discs. The valve is opened and closed by rotating the plug, after placement in the valve body, which rotates the rotatable discs with respect to the fixed disc. Nevertheless it remains desirable to provide a ventilator airway fluid collection system that is less complex and less expensive, more robust and reliable than those of the prior art, that will allow PEEP to be maintained in a patient breathing circuit when a fluid collector vial is removed for emptying. It would also be desirable to provide such a ventilator airway fluid collection system that can readily be substituted for existing fluid collection systems. SUMMARY OF THE INVENTION Briefly, and in general terms, embodiments of the present invention provide for a ventilator airway fluid collection system that permits the maintenance of PEEP in a patient breathing circuit when a fluid collector vial is removed. According to the present invention there is provided a ventilator airway fluid collection system for collecting fluid from a ventilator airway, comprising: a fluid container for containing fluid from the ventilator airway, the fluid container having an opening through which fluid is received from the ventilator airway; connector means for connecting the fluid container in sealed fluid communication with the ventilator airway, the connector means having a fluid passageway adapted to be connected in fluid communication with the opening of the fluid container; a coupling on said container for coupling said container to said connector means; and closure means disposed between the connector fluid passageway and the opening of the fluid container for opening and closing fluid communication between the connector fluid passageway and the opening of the fluid container, said closure means comprising indexing means for switching the closure means between an open position when the fluid container is coupled to the connector means allowing fluid communication between the connector fluid passageway and the opening of the fluid container, and a closed position when the fluid container is removed from the connector means, preventing fluid communication between the connector fluid passageway and the atmosphere, characterised in that the closure means comprises a disc assembly of a pair of discs consisting of a first disc fixedly mounted between the connector fluid passageway and the opening of the fluid container and a second disc rotatably mounted to the first disc, the first disc having a semicircular aperture defined therein, and the second disc having a corresponding semicircular aperture defined therein. The indexing means preferably comprises at least one tab disposed on the second, rotatable disc, and at least one corresponding locating stop on the mouth of the fluid container. The second disc can thus be rotated to the open position by rotation of the fluid container to align the second disc aperture with the first disc aperture to allow fluid communication between the connector means and the fluid container. The second disc can also be rotated to the closed position by rotation of the fluid container to bring the first disc aperture and second disc aperture out of alignment. These and other aspects and advantages of the invention will become apparent from the following detailed description, and the accompanying drawings, which illustrate by way of example the features of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an elevational view of a ventilator airway fluid collection system embodying the invention; Fig. 2 is an enlarged cross-sectional view of the union between the connector weans and fluid container of the ventilator fluid collection system; Fig. 3 is a cross-sectional view of the closure disc assembly of the ventilator fluid collection system; Fig. 4 is a bottom plan view of the closure disc assembly of Fig. 3; and Fig. 5 is a bottom plan view of the fluid collection port of the connector means of the ventilator fluid collection system. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Ventilator airway fluid collection systems in which a fluid collection vial must be disconnected in order to empty the vial can interrupt the maintenance of PEEP, if the airway is opened to the atmosphere, or if the ventilator is turned off for emptying the vial. Fluid can also be sprayed out of the airway if the ventilator is on when the fluid collection vial is removed. While spring loaded seals can be used to close off the fluid collection opening in the airway, such seals can be expensive, and difficult to clean and maintain. As is illustrated in the drawings, the invention is embodied in a ventilator airway fluid collection system 10 including connector means for connecting the fluid container in sealed fluid communication with the ventilator airway, such as a three-way or tee connector 12, typically made of silicone, that is attached to a ventilator airway line (not shown), with exhaled air or breathing gas being received in one port from a patient and exiting through another port to an exhalation module (not shown). The tee connection preferably has a bell shape to provide a relatively large area to allow for a pressure drop, to improve the flow of liquid to the vial. A fluid collection port 14 of the tee connector has a mouth opening 15 with a surface defining two key slots 16 and an inner radial groove 18 for receiving and mating with two corresponding mounting flanges or tabs 20 of a fluid container for containing fluid from the ventilator airway such as fluid collection vial 22, providing a bayonet fitting for removably coupling the vial to the connector. The radial groove serves to prevent removal of the vial unless the mounting flanges or tabs 20 on the vial are correctly oriented, so that the aperture between the patient circuit and the vial is closed off when the vial is removed. Other similar coupling means for coupling the vial to the connector consisting of similar key slots or apertures and corresponding bayonet tabs may also be suitable, such as locking tabs and slots arranged 90° apart, or with tabs or pins extending from the mouth of the connector port for the vial to mate with slots in the mouth of the vial, or the like. The fluid collection vial has a mouth defining an opening 23 through which fluid enters the vial, and which is removably connected to the fluid collection port. The fluid collection port for the vial also preferably includes another inner radial groove 24 in which a first, non-rotatable or fixed disc 26 is mounted. In a preferred embodiment, the fixed disc is made of stainless steel or a similar non-corrosive material, and includes a semicircular or 180° aperture 28. A second, smaller rotatable disc 30, also preferably made of stainless steel, and having a corresponding semicircular or 180° aperture 32, is rotatably secured to the fixed disc by a pivot pin 34 extending through the centers of the discs. The disc assembly forms a closure means for opening and closing fluid communication between the connector fluid passageway and the mouth of the tee connector and the opening of the fluid collection vial. The discs are preferably in immediate contact with one another, so that when the apertures are out of alignment in a closed position, fluid communication between the connector fluid passageway and the mouth of the tee connector is blocked. As is shown in Figs. 2-4, the second, rotatable disc preferably includes two indexing tabs 36 that cooperate with two corresponding locating stops 38 in a groove 40 in the neck flange 42 of the vial 22. At least one such indexing tab is provided on the rotatable disc, to provide an indexing means for switching the closure means between an open position when the fluid container is coupled to the connector means to allow fluid communication between the connector fluid passageway and the opening of the fluid container, and a closed position when the container is removed from the connector means, preventing fluid communication between the connector fluid passageway and the atmosphere. When the vial is attached to the fluid collection port of the connector, and the vial is rotated to lock the vial into position, the rotatable disc is correspondingly rotated to the open position, thereby opening the passageway through the fluid collection port into the vial, to permit liquid to enter the vial from the airway. Similarly, the passageway through the fluid collection port is closed when the vial is rotated for detachment of the vial, to allow PEEP to be maintained in the ventilator airway. It will be apparent from the foregoing that while particular forms of the invention have been illustrated and described, various modifications can be made without departing from the scope of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.

Claims: A ventilator airway fluid collection system (10) for collecting fluid from a ventilator airway, comprising: a fluid container (22) for containing fluid from the ventilator airway, the fluid container (22) having an opening (23) through which fluid is received from the ventilator airway; connector means (12) for connecting the fluid container (22) in sealed fluid communication with the ventilator airway, the connector means (12) having a fluid passageway (14) adapted to be connected in fluid communication with the opening (23) of the fluid container (22); a coupling (20) on said container (22) for coupling said container (22) to said connector means (12); and closure means (26,30) disposed between the connector fluid passageway (14) and the opening (23) of the fluid container (22) for opening and closing fluid communication between the connector fluid passageway (14) and the opening (23) of the fluid container (22), said closure means (26,30) comprising indexing means (36,38) for switching the closure means (26,30) between an open position when the fluid container (22) is coupled to the connector means (12) allowing fluid communication between the connector fluid passageway (14) and the opening (23) of the fluid container (22), and a closed position when the fluid container (22) is removed from the connector means (12), preventing fluid communication between the connector fluid passageway (14) and the atmosphere, characterised in that the closure means (26,30) comprises a disc assembly of a pair of discs consisting of a first disc (26) fixedly mounted between the connector fluid passageway (14) and the opening (23) of the fluid container (22) and a second disc (30) rotatably mounted to the first disc (26), the first disc (26) having a semicircular aperture (28) defined therein, and the second disc (30) having a corresponding semicircular aperture (32) defined therein. The system (10) of claim 1, wherein the fluid container (22) has a mouth defining said opening (23) in said fluid container (22), and said indexing means (36,38) comprises at least one tab (36) disposed on the second, rotatable disc (30), and at least one corresponding locating stop(38) on the mouth of the fluid container (22), whereby the second disc (30) can be rotated to the open position by rotation of the fluid container (22) to align the second disc aperture (32) with the first disc aperture (28) to allow fluid communication between the connector means (12) and the fluid container (22), and whereby the second disc (30) can be rotated to the closed position by rotation of the fluid container (22) bringing the first disc aperture (28) and second disc aperture (32) out of alignment. The system (10) of claim 1, wherein the fluid container (22) has a mouth defining said opening (23) in said fluid container (22), and said indexing means (36,38) comprises at least one tab (36) disposed in the mouth of the fluid container (22), and at least one corresponding locating stop (38) disposed on the second, rotatable disc (30), whereby the second disc (30) can be rotated to the open position by rotation of the fluid container (22) to align the second disc aperture (32) with the first disc aperture (28) to allow fluid communication between the connector means (12) and the fluid container (22), and whereby the second disc (30) can be rotated to the closed position by rotation of the fluid container (22) bringing the first disc aperture (28) and second disc aperture (32) out of alignment.

Inventors: POWER JOHN S, POWER, JOHN S.
Applicants: PURITAN BENNETT CORP, PURITAN-BENNETT CORPORATION
Application year: 1995
Main classification: A61M16
IPC codes: A61M16