SE437936B - VALVE DEVICE, Separate from an Anesthetic Unit - Google Patents

Description

8304597-1 The excess valve can be of two types: 1. Pressure-controlled, ie a spring-loaded valve plate valve that opens at a certain overpressure in the anesthesia system. This type is most common, but gives different performance to the anesthesia system if the patient breathes spontaneously or if the anesthesiologist "controls" (manages the breath for the patient) the breathing. This valve requires a manual adjustment, which makes its use more difficult and gives the risk of operating errors. 2. Volume-controlled, in which case the valve disc closes in the event of a rapid overpressure in the anesthesia system. This solution has the advantage that the system has the same performance in "controlled" as spontaneous breathing. The disadvantage is that rapid overpressure occurs for another reason, e.g. rapid fresh gas flow, the patient coughs, "irregular controlled breathing", can lock the valve in the closed position and give rise to high overpressures with the attendant risk of pulmonary rupture.

The present invention has for its object to provide a valve device which is suitable for use in anesthesia systems of various types and which thereby exhibits great safety against malfunction, such as locking in closed or open position and which has an automatic function, so that manual adjustment does not required.

The object of the invention is achieved by carrying out the device with the features stated in claim 1.

The accompanying drawings show the valve device according to the invention in two application cases with anesthesia units. The device is described in the following. The figures are 1 and '2, each of which shows somewhat schematically the different parts of an anesthetic unit, however, in order to achieve the greatest clarity, not with their correct proportions and correct relative sizes, the valve device being shown in two variants.

According to Figure 1, an anesthesia unit has a hose system 1, with a first connecting piece 2 and a second connecting piece 3 and a three-way coupling 4. The three-way coupling is connected with two of its branches 5 and 6 to a first hose 7, which opens into the connecting piece 2 , respectively a second hose 8, which opens into the connecting piece 3. A third branch 9 to the three-way coupling 4 is arranged to constitute a connecting socket for the inhalation device, by means of which the anesthetic gas mixture is supplied to the patient's airways. Such a device may consist of a mask or a tube. However, such devices are previously well known and will therefore not be described in more detail.

Connecting pieces 2 and 3 are in turn connected to a part of the anesthesia unit. which is hereinafter referred to as the control device 10. The connecting piece 2 is then connected to a socket 11, which leads to a channel 12, which at its end opposite to the connection socket 11 opens into a connection socket 13. The channel 12 has a constriction 14. Between the constriction 14 and the connecting socket 11, a connecting socket 15 and partly a side channel 16 open in the channel. A side channel 17 opens between the constriction 14 and the connecting socket 13.

The connection socket 15 is intended for a hose (not shown), which is intended for the supply of fresh gas, a mixture of anesthetic gas and oxygen from pressure vessels.

A device for supplying the anesthetic gas mixture, in addition to the hose system 1, the anesthetic mask or the like and the control device 10, constitutes the fourth part of the unit. However, such gas supply systems are previously well known and will therefore not be described in more detail in this context, which constitutes the valve device according to the invention.

The ducts 16 and 17 both lead to a valve device 20, the duct 16 leading to a first chamber 21 and the duct 17 to a second chamber 22. The chambers 21 and 22 are gas-tightly separated by means of a diaphragm 23, which carries a rod 24. When the rod 24 is passed through the walls 25 and 26 to the chambers 21 and 22, there are sealing membranes 27 and 28 in these walls. The end of the rod 24, which emerges from the chamber 22 through the membrane 27, is provided with an operating member 29.

The end of the rod 24 exiting the chamber 21 through the diaphragm 28 is located in a third chamber 30, which is enclosed by a wall 31. This end of the rod carries a valve plate 32, which can cooperate with a valve seat 33.

The valve plate and thus also the rod 24 is loaded in the direction of the valve seat 33 by a weak spring 34.

The valve seat 33 opens via a channel 35 into a connection socket 36, which carries the connecting piece 3 and the channel 35 is thus connected to the hose 8. In the third chamber 30, two further channels open, a channel 37, which ends in a connection socket 38 and a channel 39, which opens into a connecting socket 40. The connecting socket 38 is in turn intended to be connected to a container for collecting spent gas, in which gas can be stored during the exhalation periods.

The nozzle 40 is intended for connection to a hose for removing spent gas. The hose is then connected in a conventional manner to a ventilation system (not shown).

The remaining connection to the channel 12, the connection socket 13 is arranged for connection of a so-called breathing balloon. Such a balloon consists of a bladder 42, usually of rubber, which operates between a more or less coincident state and a filled state. On the other hand, no tensioning of the material in the bladder 42 occurs during work, since the assembly is not intended to work at such pressures which could produce such tensioning. The movements of the balloon indicate the patient's breathing and the inhalation can be supported by pressure around the bladder. However, this device is also well known in the art. As can be seen from the description given, the space, hereinafter referred to as the primary space, represented by the patient's lung bladders, the patient's airways and said device such as a mask, a pharynx or the like, opens into the three-way coupling 4 and connects to two chambers, a first chamber 44, which is represented by the hose 7, the connecting piece 2, the duct 14 and the breathing bladder 42, to which chamber the two chambers 21 and 22 in the valve device 20 are further connected. This chamber 44 is in turn connected to the gas supply system through the connection socket 15.

To the primary room, which comprises the patient's respiratory system, is connected via the three-way connection 4 parallel to the room 44 a second room 45, which is represented by the hose 8, the connecting piece 3 and the channel 35. The room 45 is also connectable via the valve seat 33 to the third room 30 in the valve the device 20 and from this there is, as mentioned, a free outlet for the gas.

If it is assumed that an inhalation is to be started and that the space 44 is filled with an unused anesthetic gas mixture, then the inhalation will lead to this gas mixture via the three-way coupling 4 rushing into the said primary space. In this case, gas mixture is taken from the bladder 42, which gas mixture must rush through the channel 12. The supply of fresh gas through the connection nozzle 15 is namely regulated so that the amount of gas supplied in this way is not sufficient for the flow which flows into the patient during inhalation. As the gas flows through the channel 12, its velocity will increase in the constriction 14, leading to a negative pressure in the constriction and shortly thereafter in relation to the pressure on the inflow side, where gas flows from the bladder 42 to the constriction 14. The pressure in the space 21 in the valve device 20 thus becomes lower than the pressure in the space 22. This means that the valve plate 32 is applied to the valve seat 33 and the force formed by the difference in the gas pressures is supported by the force from the spring 34. The valve plate 32 thus seals against the valve seat 33 and any flow of gas through the hose 8 can not take place, but the gas volume in the room 45 is maintained in this room.

When the next exhalation begins, the valve 32, 33 is still closed; the spring 34 always gives an initial pressure even if the rod 24 would not be affected by any pressure difference on both sides of the diaphragm 23. This means that the gas mixture flowing through the three-way coupling 4 will not be pushed into the hose 8, because the back pressure in this branch , the space 45, through the closed valve is higher than in the space 44 connected to the hose 7. During the mentioned gas mixture is mentioned as mentioned gas mixture from the bladder 42, so that it is collapsed when the exhalation begins and the exhaled gas mixture can thus rush into the room 44 to its bladder filled. However, this direction of gas flow leads to a pressure ratio in the channels 16 and 17, which is reversed to what was the case during inhalation. Thus, the pressure in the first space 2] will be higher than the pressure in the second space 22, which leads to the rod 24 and thus the valve plate 32 being affected by a force in the direction of the seat 33. This leads to that when the exhalation has been going on for a certain period of time the valve plate 32 will be opened from the seat 33, the back pressure in the chamber 45 being very low and lower than in the chamber 44. The remaining gas mixture exhaled from the primary run will then be diverted to the hose 8 and out through the valve and further for venting through the channel 39 and the nozzle 38. Gas which during the exhalation period does not have time to be handled by the ventilation system flows via the nozzle 38 to the said storage volume. In the first instance, the amount of gas trapped in the space 45 is thereby forced out of the inflowing gas.

When the exhalation ceases, so that the pressure difference between the chambers 21 and 22 is no longer able to overcome the force from the spring 34, the non-return plate 32 closes and the last exhaled gas volume is trapped in the chamber 45.

In addition to the valve opening and releasing excess gas as described above during a normal exhalation, any gas flow direction corresponding to that when exhaling past the constriction 14 will open the valve, ie if a flush of fresh gas is supplied to the system or if the patient coughs, and without any risk for locking the valve.

On the next inhalation, the closed valve 32, 33 again forms an obstacle for the gas in the space 45 to be sucked back to the primary space as previously described. In contrast, the first outflowing portion of the exhaled air is stored in the space 44 and will form part of the gas mixture being inhaled.

The described function thus means that a first volume of the exhaled air is collected in the control device 10, mainly in the bladder 42, while a last volume of the exhaled air is removed. Upon inhalation, a gas mixture is inhaled, composed of the first part of the gas mixture exhaled during the previous exhalation, which is stored in the control device, and fresh gas supplied from the previous inhalation. By suitable adaptation of the unit, it can then be achieved that the first exhaled gas volume, which is stored in the control device, essentially corresponds to the dead-space volume, which has never reached the alveoli and which is thus unused. The last exhaled part, which is gradually ventilated away by means of the control device, will, on the other hand, mainly correspond to the gas volume which has reached the alveoli and which is thus counted as consumed and therefore should not be supplied to the patient again.

Such a complete adaptation of the unit that the two parts of the exhaled volume are completely separated from each other for re-inhalation and venting, respectively, is of course impossible to achieve. The relationship between the dead-space volume and the total respiratory volume thus differs from patient to patient and is otherwise impossible to measure with any greater accuracy.

In addition, the respiration can be deeper or shallower and a certain mixing within the gas mass takes place during the flow. However, such an adaptation should be preferred, which provides some ventilation of non-consumed gas, which must thus be replaced with fresh gas, while re-inhalation of spent gas containing carbon dioxide is avoided.

The adaptation to the desired result takes place by adapting the different volumes to each other and also by adapting the flow areas.

In addition, the channel 12 with its constriction 14 and the design and placement of the branched channels 16 and 17 must be made with great care, so that the valve 32, 33 is opened when the space 44 is filled, this space being adapted to receive said first part of the exhaled gas. . The valve must allow a sufficiently rapid venting of the gas in the space 45, so that such a back pressure, which disturbs the function, is not formed. It is also important that the valve 32, 33 closes quickly when inhalation is started, otherwise a recirculation of the spent gas in the space 45 can take place. At what pressures and at what times the valve 32, 33 operates, are determined by several factors such as the volume of the chambers 21 and 22, the area of the diaphragm 23 and the spring 34 and also the working pressure in the space 45 against the valve plate 33. Further affects the moving masses of the vein - tilen the process and these should be kept as small as possible.

The operating member 29 on the rod 24 enables manual opening of the valve disc 32, so that the through-ventilation of the space 45 can be influenced, for example, at the beginning and end of an anesthesia.

As can be seen from the foregoing description, the basic ideas of the invention in the system according to the example are that the exhaled gas quantity is controlled in a time course into two chambers, the first exhaled part into a first room for re-inhalation and the last exhaled part into a other rooms for exhaust ventilation.

This control of the gas portions takes place with the valve according to the invention which always opens on exhalation and / or temporary high flows of fresh gas into the system. This valve cannot lock so that large static pressure loads occur in the patient's chest and it does not require any manual adjustment.

The control is achieved by the valve device sensing the flow direction in channels belonging to the first space, so that inflow at the exhalation initiates that the gas flow is reversed to the second space after a certain period of time while outflow from the first space during an inhalation initiates that the second space closed in such a way that herring from this can not take place. As mentioned, the special valve according to the invention is arranged for said deflection of the flow direction. This controls the flow relative to the second compartment, in such a way that during the first exhalation period inflow cannot take place, whereby the gas flow is linked over to the first compartment, and so that outflow from the second compartment to the patient is prevented at all. while outflow for exhaust ventilation is allowed. This control of the flow in relation to the second space takes place according to the previous description by means of a valve in the inner part of the second space, which when closed prevents both inflow into the gas-filled space and outflow from the same, while in open position it allows venting away. of gas from the room, whereby gas can flow in at the same time.

The valve device 20 in Fig. 1 can be modified according to Fig. 2, so that it can be used in other anesthesia systems such as circular systems or Mapleson D systems. In the embodiment according to Fig. 2, a socket 50 is connected to an anesthesia system (circular system or, Mapleson D for example).

The socket 50 is connected by means of a channel 53 to a second socket 54, which carries a breathing bladder 55. The channel 53 has a constriction 56, from whose end facing the socket 50 a side channel 57 emanates and from whose end facing the socket 54 a side channel 58 emanates The side channels 57 and 58 each open into a chamber 59 and 60, respectively, to a valve device 61.

The valve device 61 is in principle of the same type as the previously described valve device 20 and thus has a housing 62, in which the chambers 59 and 60 are located, a diaphragm 63, which forms a partition wall in the housing 62 between the chambers 59, 60, a valve seat 64, which can be sealed with a valve body 65, which is connected to the diaphragm 63 by means of a rod 66. The valve seat 65 forms a connection between the chamber 60 and an evacuation channel 67 for spent gas, and which can be compared with the evacuation channels 38, 39 in the first embodiment. - the form. A weak spring 68 strives to keep the valve body 65 closed, thus abutting the seat 64.

In this embodiment, as before, fresh gas is supplied, for example, through a nozzle 69 in a matched stream in an anesthesia system of some suitable type.

With a sufficiently strong or rapidly increasing gas flow in the direction of the breathing bladder 55 past the constriction 56, the valve will open, regardless of whether the gas flow is caused by exhalation, coughing shock or a large fresh gas flow.

Thus, on exhalation, the exhaled gas will flow into the nozzle 50 and on to the duct 53. Due to the higher pressure before the constriction 56, the pressure in the chamber 59 will be higher than in the chamber 60, which leads to the manifold 63 opening the valve body 65. It passes the constriction The gas flowing 56 is thus released freely through the evacuation channel 67 via the side channel 58 and the chamber 60. Only when the exhalation has stopped will the valve close, whereby the fresh gas will fill the breathing bladder 55 and the hose 52. In the case of breathing assistance by compressing the breathing bladder 55, it will lead to higher pressure in the chamber 60 than in the chamber 59, which leads to the valve being kept closed, so that no fresh gas is lost.

The described valve device has * proved to work well and is relatively simple in its design and is taken from the technical field which has previously existed in the context, whereby the understanding of the apparatus and its maintenance is facilitated for the person who is to handle it. It is therefore extremely well adapted as a component of anesthesia systems, which, as mentioned, can be of different types.

Claims (3)

8304597-1 PATagjKRAv Valve device in particular in an anesthetic unit, comprising an inhalation device, such as an anesthetic mask, a gas supply system for supplying a gas mixture consisting of oxygen and anesthetic gas, at least one valve (32, 33; 64, 65) for controlling the gas flow in the unit and preferably an outlet (37; 67) for controlled discharge of spent gas, characterized in that a control device (12, 14, 20) is arranged for the opening and closing of the valve (32, 33; 64, 65). 53, 56, 61), which comprises a sensing device (12, 14; 53, 56), arranged to sense the gas velocity and the gas flow direction in a gas path in the unit, and a force device (20; 61) arranged to open the valve (32, 33; 64, 65) in the unit when the gas velocity in a predetermined direction, for example by a violent exhalation or a cough shock of the patient connected to the inhalation device or by controlled generation of a gas stream, exceeds a certain, predetermined value by the sensing device and allowing the valve to be closed when said predetermined gas velocity is exceeded, the sensing device comprising a channel (12; 53) with a constriction (14; 56) and inlets placed on both sides of the constriction to two side channels (16, 17; 57, 58), and that the force device (20; 61) is arranged to control the valve (32, 33). 64, 65) to its different positions by utilizing the higher pressure which, depending on the direction of flow of the gas and its flow velocity, arises on the inflow side of the constriction in relation to the lower pressure downstream of the constriction, and is formed by two chambers (21, 22; 59, 60), which are connected to each of said side channels (16, 17; 57, 58) and which are separated by a member movable towards and from the respective chamber, such as a diaphragm (23; 63) to which the valve (32, 33; 64, 65) is connected, so that said pressure difference, which arises in the sensing device, causes a movement of the member and thus a control of the valve. Valve device according to claim 1, characterized in that the diaphragm (23) is arranged to actuate the valve together with an initial force, for example a spring force, in such a way that flow in one direction tends to open the valve against the action of said initial force while a flow in the other direction tends to close the valve under the support of said initial force due to the difference between the pressures in the two chambers (21, 22) caused by the flow past the constriction. Veritilzinrxrtlnírig according to claim 1 or 2, characterized in that the kšinsvlanortlningen (12, 14; 53, 56) is connected to the portion of (less channel (12, 53) which is located on a side of the displacement fan (ll; 56) to an expandable and compressible bladder (42) and that the force device (20; 61) is arranged to actuate the valve (32, 33; 64, 65) located in said outlet (37; 67), so that it closes when a controlled gas flow is generated by compressing the bladder.