The present invention relates to an arrangement in appa¬ ratus with which a gas or gaseous mixture is spontaneous¬ ly inhaled or forcefully induced into the respiratory sy- stem of a patient; in which the gas or gaseous mixture is taken from a pressurized gas-source and administered to the patient through a face mask or a tracheal tube; and ih'which valve means are provided for controlling the pha¬ se-volume gas flow from the gas source.

Apparatus of this kind are used, inter alia, to adminis¬ ter a full anaesthetic to patients undergoing surgery. The anaesthetic is often administered initially through a face mask, which is pressed against the patient's face and covers the externally opening respiratory ducts, i.e. the nose and mouth. The anaesthetist will then quite often transfer from this type of administering mode to one in which the anaesthetic is administered through a tube which enters the tracheal tube, through the nose or πouth of the patient. At times it is necessary for the anaesthetist to check the colour of the patient's face visually during the initial anaesthetizing stage, and also during the ope¬ ration itself, and if required to free the patient's mouth, throat (and tube) from mucus.At these moments it is necesse- ry to lift the mask from the patient's face , or to loosen the tube from the gassupply line, thereby permitting anaes¬ thetizing gas to freely flow into the operating theatre. Consequently, it is quite likely that the anaesthetizing gas will be released into the theatre at dangerously high levels, both prior to and during an operation, exposing the surgeon and the theatre staff to grave risk, since their health can be adversely affected in this way.

Although it is known to include in the supply system val¬ ve means for temporarily cutting the supply during the 'aforesaid moments when the face mask, or tube, are relea-

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sed, cfT for example U.S.Patent Specification No. 151 843, they are both complicated and unable to carry out the fun¬ ctions given below.

As will be understood, there is a great need for a struc- 5 tually simple valve means with which the supply of anaes¬ thetic to a patient can be stopped by simple manual mani¬ pulation at the aforesaid moments, when it is necessary to check the colour of the patient's face etc.

Consequently an object of the present invention is to pro- 10 vide an arrangement in anaesthetic administering apparatus which solves the aforementioned problem and which satisfies this desideratum.

Accordingly, this invention consists in an arrangement of the aforementioned kind in which the valve means is

15 located between the face mask, or tracheal tube, and a nip¬ ple connected to the gas supply line; in which the valve body of said valve means can be manually manipulated be¬ tween- a first position ±n which said gas can flow freely to said patient, and a second position in which the gas

20 flow to said patient is fully blocked; and in which the valve body is springbiased towards said second position.

As a result of the proposed design and positioning of the valve means according to the invention, it becomes naturally a readily manipulated, complement to both face

25 mask arid tracheal tube. In practice, it is unnecessary for the anaesthetist to learn new ways of holding and manipulating the face mask etc. , since the positions of the hands and the position of the anaesthetizing equip¬ ment while an anaesthetic is being administered are prac-

30 tically the same as before. In normal operation, the val¬ ve body or plate is moved by exerting a slight finger pressure or hand pressure thereon.

The invention will be now described in more detail with reference to two exemplary embodiments thereof, which shall not be considered to restrict the scope of the in¬ vention.

Figure 1 illustrates in two parts a first embodiment of valve means according to the invention, the upper part of said Figure showing the position of said valve means in which the supply of gas to a patient is fully blocked, while conversely the lower part illustrates the valve means in a position in which gas can flow to the patient via a tracheal tube. Figure 2 illustrates a second embodiment of the invention.

In the illustrated embodiments gas or a gaseous mixture is taken from a pressurized source and supplied to an an- gular inlet nipple 10, from where the gas flows through a valve means 11 detachably connected to the nipple 10. The valve means 11 is, in turn, detachably connected to a face mask 12, arranged to be pressed over the nose and mouth of a patient, in a manner known per se. As will be understood, the illustrated face mask can be replaced with a tracheal tube, such as tube 13 shown in the lower part of Figure 1.

As shown in Figure 1 , the valve means 11 includes a tubu¬ lar body 14 provided with an upper flange 15 having an ope- ning therein for receiving the detachable nipplecoupling 10, and a lower flange 16 having an opening therein for detachably receiving a conventional face mask 12 or tra¬ cheal tube 13. Mounted for rotation in the tubular body 14 is a cylindrical valve element 17, one end of which pro- jects beyond the tubular body 14. This protruding end of the valve element 17 is provided with a hand grip 18. The valve element 17 is also provided with mutually oppo¬ site openings 19 which in one position permit gas to flow

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to the face mask 12, and in another position completely block said gas flow. Preferably, the valve element 17 is spring biased towards its gas-flow blocking position.

The valve means illustrated in Figure 2 is principly of the same construction as the valve means of Figure 1. In the Figure 2 embodiment, the valve body 11 comprises a plate-like body 20 comprising two detachable parts, the upper part of which exhibits a flange 15 provided with an opening for detachably receiving the nipple- -coupling 10, and the bottom part of which has a corres¬ ponding flange provided with a corresponding opening for detachably connecting the face mask 12. A spring-biased plate 21 is arranged for horizontal movement in the bot¬ tom plate of said valve body 11 , and is provided with an opening 22 which, in the illustrated position, lies outside the plate-like body 20 and therewith blocks the supply of gas to the mask 12. When the plate 21 is pres*~ sed in against the action of springs 23, to a position where an edge stop means 24 abuts the adjacent end of the body 20, maximtαm flow of gas to the mask 12 is per¬ mitted.

The valve is opened by applying a light finger pressure to the hand grip 18 or to the plate 21. When wishing to check, for example, the colour of the patient's face, the mask is lifted and, at the same time, the pressure on the hand grip or the plate is released and the flow of gas blocked.

When the anaesthetic is administered through the tracheal tube, the nipple-coupling 10 can be inserted into the flan- ge 16 (and correspondingly in the Figure 2 embodiment) to such an extent that the valve is held in a fully open position. When the tube and the valve are separated, the spring action will cause the flow of gas to be blocked.

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