CH634901A5 - Pneumatic device intended to be plugged into an appliance for administering gases - Google Patents

Description

The subject of the present invention is a pneumatic device intended to be plugged into an apparatus used to administer gases and, in particular, a pneumatic device such as a vaporizer intended to be mounted on an apparatus serving to administer gaseous analgesics or anesthetics ( which will be generally designated below by anesthetics) or other medical gases or mixtures of gases such as oxygen or air.

For the purposes of this description, the term pneumatic device designates any type of device that can be mounted on an apparatus used to administer gases and capable of receiving gas during the operation of the apparatus. The term pneumatic device thus includes, among others, vaporizers, flow meters, gas mixers, volumeters, fans, pressure gauges and absorbers.

In the disclosure of invention of GB Patent No. 1385670, there has been described an apparatus for administering gases, on which one or more pneumatic devices can be mounted in a pluggable and removable manner. A plug-in device of this type simplifies the installation of the pneumatic devices on the device and subsequently their removal, which facilitates the maintenance and cleaning of the pneumatic devices as well as the replacement of a pneumatic device which breaks down during of an operation. In addition, this device is very useful for anesthesiologists, because it allows them to carry out an easy and rapid change of one or more of the pneumatic devices, for example of one or more vaporizers mounted on a given anesthesia machine. In this way the apparatus can easily be adapted to administer one or the other (or several) of a large number of volatile anesthetic agents currently available, and the anesthesiologist can thus ensure that the specific agent correct is administered to each patient.

Known pneumatic devices arranged to be plugged in, as described above, generally comprise a locking member or mechanism cooperating with a bar or support structure with internal conduits of the anesthesia machine, so as to lock the device in place pneumatic after it was installed. The locking operation can also be used to press the device tightly against seals arranged around nozzles cooperating with the device and which the anesthesia machine presents in order to ensure the arrival of gas at the pneumatic device. However, it is possible to install a known device of this type, then to actuate the device without the locking having been brought into the active position. The pneumatic device fitted, but not locked, may be accidentally moved or, in any case, gas leaks may occur at the seals which have not been compressed - because the locking operation does not has not been done - and which is thus not very effective.

The pneumatic device which is the subject of the invention, intended to be removably plugged into an apparatus serving to administer gases, comprises means for controlling admission into the gas device supplied by a source coming with the apparatus, and a locking mechanism intended to cooperate with the device to lock the device in place when it is mounted on the device, and it is characterized by an interlocking system such that bringing the control means into an active position ensuring admission to the device of gas from the device is prevented if the locking mechanism has not been brought into a position where it ensures the locking of the pneumatic device on the device.

It is thus certain that the pneumatic device cannot be inserted into the gas circuit without having been correctly locked in place on the apparatus and, in the case where a pneumatic device has been installed, but not locked in place, the operator immediately realizes this since he cannot manipulate the control means of the device.

The nozzles of the known plug-in type anesthesia machines intended to supply gas to the removable pneumatic devices generally include resiliently biased plugs which, when no pneumatic device has been installed, close the corresponding nozzles to prevent them from communicating with the atmosphere but which, when a device has been installed, are moved out of the closed position by their coming into contact with actuating members which the pneumatic device comprises, in order to ensure communication between the nozzles and the device.

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As long as the pneumatic device remains mounted on the device, the corresponding shutters remain open even if the pneumatic device control means are in the closed position. Thus, even if one does not want the pneumatic device to be inserted in the gas circuit, residual gases or steam remaining in the internal passages of the device, between said nozzles and control means, can be introduced into the circuit. In addition, if the pneumatic device is constituted by a vaporizer and its control means consist of a valve which does not close perfectly in the closed position, appreciable quantities of unwanted vapor can be introduced into the circuit, without the the anesthesiologist realizes it.

It is clear that such a situation is not acceptable and in a preferred embodiment of the invention, it is sought to eliminate this difficulty.

Thus in this preferred embodiment, the control means control the admission into the pneumatic device of gas supplied by a source through at least one nozzle of the apparatus, said nozzle comprising a shutter normally stressed in a position where it closes the nozzle, and the locking system comprises at least one actuating pin arranged so that, when the pneumatic device is mounted on the device, said actuating pin does not move the shutter of said nozzle out of its closed position only when the control means have been brought into their active position.

It is common to mount two separate vaporizers on an anesthesia machine, so that two different anesthetic and volatile agents can be supplied to the same carrier gas, so that the same anesthesia machine can be used in a series of surgical operations where different patients require different anesthetic agents. It is clear that, in this case, it is necessary to avoid the risk that the two anesthetic agents are delivered at the same time to a patient or mixed in some other way. Apart from the case where several optional vaporizers are provided, there may be others where it is desirable that an anesthesia machine or other device serving to administer gases is equipped with two optional pneumatic devices, or more, therefore should not again be able to be used at the same time. For example, one can mention the case of a device equipped with two pneumatic devices, for example coin-flow meters to operate in different ranges of gas flow rates, or of a device equipped with both a trichlorethylene vaporizer and a '' a COz absorber consisting of soda lime (which an anesthesiologist may have to use during different operations, but which should not be used at the same time since trichlorethylene can react with soda lime to produce a toxic gas ).

Known anesthesia machines which make it possible to have several vaporizers of choice are generally equipped with the bar, or support structure, already mentioned, on which the vaporizers are mounted and which presents the tubing or the channels necessary to allow each vaporizer to be inserted into the gas circuit. In order to avoid the possibility of mixing the different vapors, it is known to provide a selection valve by means of which the support gas can only be supplied to that of the vaporizers which has been chosen at a given time. However, this system has the drawback that it is necessary to actuate two valves to insert the chosen vaporizer into the circuit, namely the selection valve on the support bar and the control valve on the vaporizer which allows the passage of the support gas. through the vaporizer and fixes the concentration of the vaporized agent supplied to the support gas. In addition, in this system, it may nevertheless happen that, as a result of incorrect handling, either an incorrect agent, or an incorrect concentration of the correct agent, or even no agent at all is delivered to the patient without the the anesthesiologist realizes it immediately.

The preferred form of the invention also aims to eliminate or at least reduce the difficulties inherent in the use of a selection valve in a multiple choice anesthesia machine,

while ensuring that only the vaporizer chosen from among two or more possible vaporizers can be inserted at the same time into the gas circuit.

To this end, in the preferred embodiment, the locking system comprises at least one pin which can be deployed, outside the pneumatic device, when the control means are brought into their active position, in order to prevent the means from control of an adjacent similar pneumatic device mounted on the apparatus to be able to be brought into their active position. In the accompanying drawings, given by way of example:

fig. 1 is a schematic plan view of two optional pneumatic devices (vaporizers), that is to say to be used only one at a time, mounted on the support bar of an anesthesia machine,

fig. 2 is a more detailed plan view of one of the vaporizers of FIG. 1, with certain parts partially removed or torn off,

fig. 3 is an elevational view in partial vertical section of the vaporizer of FIG. 2,

fig. 4, 5 and 6 are sectional views of details of the vaporizer of FIGS. 2 and 3, and figs. 7A and 7B are schematic views of the device provided on the anesthesia machine for plugging in each of the vaporizers, this under two different operating conditions.

The two pneumatic devices shown in fig. 1 consist of vaporizers 2 and 3 mounted one next to the other, on a support bar 1 with internal conduits of an anesthesia machine, and serving to supply different volatile anesthetic agents. The vaporizers are detachably plugged into the support bar by means of pairs of rising nozzles 4A, 4B integral with the support bar, which are inserted into corresponding cavities 5 formed in the rear part of the vaporizers (see also Figs. 3 and 6).

Means are provided for locking each of the vaporizers in place on the support bar. These means comprise a pivoting rod 6 carried by the sprayer, which sinks into a cavity 7 formed in the support bar when the sprayer is applied to its nozzles 4A and 4B. The rod 6 has a profiled groove 6A (FIG. 5) engaging a retaining element 7A in the cavity 7 when the rod is pivoted by 90 ° by a lever 8 actuated by the thumb, that from the position indicated in FIG. 1 for the vaporizer 3 at the position indicated for the vaporizer 2. The actuation of the latch has the effect of preventing the vaporizer from being moved relative to the support bar and is also used to press the rear part tightly spray against the support bar, which ensures gas tightness with annular seals 9 arranged around the bases of the nozzles 4A and 4B. It should be noted that the lever 8 of the vaporizer 3 is shown in the unlocked position in FIG. 1 only for explanatory purposes, since in order for a vaporizer to function once it has been placed on the support bar, its lock must be in the active position. In fact, as will be described in more detail below, it is impossible to insert such a vaporizer into the gas circuit until it is locked to the support bar.

Means are mounted on the top of each of the vaporizers to control the admission of gas into the vaporizer. These means include a dial 10 for indicating the concentration, coupled to a rotary plate or other control valve disposed inside the body of the vaporizer. It will be assumed that each of the vaporizers is of the bypass type, as described for example in the disclosure of invention of GB patent No. 1224478, comprising a vaporization chamber in the lower part 11 of the vaporizer (fig. 3) and a bypass circuit of the vaporization chamber. During operation, the support gas supplied to the vaporizer is divided into two flows, one passing through the vaporization chamber and the other through the bypass circuit, the two flows then being combined before leaving the vaporizer. The details of the construction of the control valve will not be described here; suffice it to say its function is to vary the proportion between the

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gas flowing through the vaporization chamber and that flowing through the bypass circuit, depending on the position of the dial 10, which makes it possible to vary the concentration of the anesthetic agent vaporized in the flow Release. The dial carries a graduated scale indicating the concentration of anesthetic fixed by the control valve and also indicating the "Closed" position in which the control valve interrupts the flow of gas through the vaporizer.

As can be seen in Figs. 2 and 3, an annular cam 12 is mounted under the dial 10 so that it can rotate with it.

This cam has an inclined shoulder 12A separating the lower flat bearings 12B and upper 12C. The cam 12 cooperates with a crank 13 carried along its middle part 13 A. Its end parts, offset, 13B and 13C, rest respectively on the surface of the cam 12 and the surface of a platform 14 with movement of vertical back and forth. The platform 14 is carried by two plungers 15 resiliently biased (one of which is visible in FIG. 6). These divers urge the platform upwards against the part 13C of the crank, which in turn biases the part 13B of the crank down against the surface of the cam 12. When the concentration indicator dial 10 is in the "Closed" position (and that, consequently, the control valve is closed) the part 13B of the crank presses on the lower bearing 12B of the cam and the platform 14 can, therefore, be raised to its position upper, (shown in fig. 3). However, when the dial is moved (counterclockwise) from the “Closed” position to an active position to open the control valve, the part 13B of the crank is brought up the shoulder 12A to arrive at the upper bearing 12C of drug. In doing so, the crank is pivoted to the position shown in fig. 2, so that in turn the part 13C of the crank pushes the platform 14 down against its elastic stress.

A spindle 16 capable of reciprocating movement in a bore 17 extends downward from the rear of the platform 14. The bore 17 is intersected by a horizontal bore 18 in which are housed two pins 19A and 19B resiliently biased towards each other (fig. 4). As long as the platform 14 remains in its upper position, the pin 16 is kept away from the bore 18, and the pins 19A and 19B are entirely contained in this bore. However, when the platform is lowered after rotation of the dial 10, the pin 16 enters the bore 18 and spreads the pins 19A and 19B. In this condition, the free ends of the pins emerge from the opposite ends of the bore 18, as shown in FIGS. 1,2 and 4 for vaporizer 2.

It can thus be seen that each time the control valve of a vaporizer of the type described above is brought into a position ensuring the admission of gas into the vaporizer, the two pins 19A and 19B extend out of the pneumatic device, on either side of it. Returning to fig. 1, it can be seen that the dial of the vaporizer 2 has been moved from the “Closed” position to an active position, in order to open the control valve associated with it and that, consequently, the pins 19A and 19B have been deployed . If we now try to turn the dial of the vaporizer 3 (it being admitted that its lock has already been actuated), its two pins 19A and 19B will also tend to be deployed by means of its cam 12, the crank 13, the platform shape 14 and the pin 16. However, the deployment of the pin 19A will be blocked by the pin 19B of the vaporizer 2 and, thus, the movement of its dial 10 is prevented.

We therefore see that, thanks to this arrangement, it is impossible to insert more than one vaporizer at a time into the gas circuit and that the interlocking system, described above, comprising the pairs of pins 19A and 19B , will be equally operating between any pair of similar vaporizers (or other pneumatic devices provided with a similar mechanism) occupying the two mounting stations defined by the pairs of nozzles 4A and 4B of the support bar.

As indicated above, the vaporizers 2 and 3 each include a mechanism to prevent actuation of the vaporizer if it is not locked in place on the support bar 1. This mechanism will now be described with reference to FIGS. 2 and 5.

A circular plate 20 comprising two vertical pins 21 is fixed to the rod 6, below the platform 14. When the rod is pivoted in the “Locked” position, the two pins 21 come opposite corresponding holes 22 formed in the platform 14, so that any subsequent movement of the dial 10, for example to lower the platform, is not hampered. However, when the rod 6 is in the "Unlocked" position, the pins 21 are located opposite the non-perforated parts of the platform. Consequently, in this condition, the lowering of the platform is prevented, and the dial 10 cannot be pivoted out of the "Closed" position.

Another characteristic of the embodiment shown resides in the means by which the nozzles 4A and 4B of the support bar, associated with each of the vaporizers, are only opened when the control valve of the corresponding vaporizer is open. Fig. 7 shows the arrangement of these nozzles provided in each of the mounting posts of the support bar. The nozzles 4A and 4B communicate with corresponding bores 23 A and 23 B formed in the support bar, the bore 23 A being connected to an inlet channel 24 of the support gas and the bore 23B to an outlet channel 25. The two bores are connected by a channel 26. A plug 27 in the form of a piston and a rod 28 are arranged in each of the bores 23 A and 23B, each being biased upwards by a spring 29.

Fig. 7A shows how the nozzles appear when no vaporizer is mounted at this station or when a vaporizer is in place, but is not engaged. In this condition, each nozzle is closed and the inlet and outlet channels 24 and 25 are connected together by the channel 26. However, when a vaporizer is mounted at this station and its control valve is open, the consequent lowering of the platform 14 lowers actuation means constituted by pins 30 (fig. 3 and 6) on the valve stems 28, in order to move the shutters 27 in the positions indicated in fig. 7B. In this condition, the nozzle 4A communicates with the inlet channel 24, the nozzle 4B communicates with the outlet channel 25 and the channel 26 is closed. The support gas can penetrate into the corresponding cavity 5 of the vaporizer from the nozzle 4A and pass through a lateral bore (not shown) of this cavity in the body of the vaporizer, in order to be divided into two streams as described here. above (it should be noted that in this condition the upper opening 5 A of the cavity is closed by an O-ring seal 30A disposed around the actuating pin 30 of the valve). After the flows have been combined, the support gas / vapor mixture is sent to the other cavity 5 of the vaporizer, then passes through the nozzle 4B and into the outlet channel 25 of the support bar.

It follows from the above that when a vaporizer is mounted on the support bar the corresponding nozzles of the support bar are closed and the vaporizer is completely isolated from the gas circuit as long as its dial 10 has not been moved out from the "Closed" position to open the corresponding control valve. If a vapor leak occurs from the vaporizer for some reason, this vapor can be evacuated from the cavities 5 through the upper openings 5A (the pins 30 being removed in this condition) and then, into the atmosphere, by other suitable openings provided for this purpose.

On the other hand, while the vaporizer at one of the stations (2 or 3) is not engaged, the corresponding nozzles 4A and 4B are short-circuited by the support gas which flows through the channel 26, ce. which allows the other station (3 or 2) to be connected in series to the support gas source. Thus, for example, and referring to FIGS. 7A and 7B, the outlet channel 25 of the station shown constitutes the inlet channel of the next station. By using a serial connection of this type, instead of the parallel connection, more often used in devices

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anesthesia allowing a multiple choice of vaporizers, the amount of dead tubing in the support bar can be reduced to a minimum, which reduces the risk of danger inherent in the accumulation of explosive vapors, such as ether, in such piping. s

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As a variant, it is possible to use the actuating pins 30 to actuate valves or mechanisms other than the shutters 27, these mechanisms being able for example to provide a connection to a pressure gauge functioning only when the control means are brought into their active position.

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Claims (6)

634,901 1. A pneumatic device intended to be removably plugged into an apparatus serving to administer gases and comprising means for controlling the admission into the gas device supplied by a source coming with the apparatus, and a locking mechanism intended to cooperate with the device to lock the device in place when it is mounted on the device, characterized by an interlocking system such as bringing the control means (10) into an active position, ensuring admission into the device (2) of gas coming from the appliance (1), is prevented if the locking mechanism (6, 8) has not been brought into a position where it ensures the locking of the device on the appliance. 2. Device according to claim 1, wherein the control means control the admission into the gas device supplied by a source by at least one nozzle (4A, 4B) of the device, said nozzle comprising a shutter (27) normally stressed in a position where it closes the nozzle, characterized in that the interlocking system comprises at least one actuating pin (30) arranged so that when the pneumatic device (2) is mounted on the device ( 1) said actuating pin (30) moves the shutter (27) of said nozzle (4A, 4B) out of its closed position only when the control means (10) have been brought into their active position. 2 3. Device according to one of claims 1 or 2, characterized in that the interlocking system comprises at least one pin (19A, 19B) which can be deployed outside the device (2), when the control means (10) are brought into their active position, to prevent the control means (10) of a similar adjacent pneumatic device (3) mounted on the device (1) from being brought into their active position. 4. Device according to claim 3, characterized in that it comprises two elastically biased pins (19A, 19B) which can be deployed on either side of the device (2) against the elastic bias exerted on them, the pins (19A, 19B) being able to be moved towards their deployed position by another pin (16) extending below a platform (14) resiliently biased, so as to be able to effect a back and forth movement - comes in a passage (17), this other spindle (16) being forced between the elastically stressed pins (19 A, 19B) during the movement of the platform (14), against its elastic stress, caused by the rotation of a crank (13) of which an end portion (13C) bears against the platform (14), the crank (13) being able to be rotated by a cam (12) which can itself rotate under the effect of the rotation of a dial (10) forming part of the control means. 5. Device according to any one of claims 1 to 4, characterized in that the locking mechanism comprises a pin (6) mounted on the device (2) and which can pivot between a locking position and an unlocking position, l 'axis (6) having a profiled groove (6 A) intended to engage a locking element (7 A) formed in a cavity (7) of the device (1). 6. Arrangement according to claim 5, characterized in that the interlocking system comprises a plate (20) comprising at least one rising spindle (21) which, during the rotation of the axis (6) in its unlocked position , engages the platform (14) to prevent movement of the platform (14) against its elastic stress and, therefore, to prevent the control means (10) from being brought into their active position.