WO2009033462A1

WO2009033462A1 - Device for providing anesthetic gas

Info

Publication number: WO2009033462A1
Application number: PCT/DE2008/001499
Authority: WO
Inventors: Karl Cornelius-Lorenz; Kirsten Klein; Thomas Kriesmer; Klaus Züchner
Original assignee: Technologie Institut Medizin (Tim) Gmbh
Priority date: 2007-09-10
Filing date: 2008-09-09
Publication date: 2009-03-19
Also published as: DE112008003093A5

Abstract

The invention relates to a device for providing anesthetic gas. The device consists of a storage tank and a conveying and metering device which generates the anesthetic steam pressure as the drive energy for conducting saturated anesthetic steam due to an increase in temperature and without needing a supply in transport or inlet gas from the exterior. Said device comprises a temperature- and/or pressure-controlled anesthetic agent evaporator and pressure generator, consisting of the storage tank (3) itself, a heating device (5) controlled by a control/regulation device (9) and temperature (8) and/or pressure sensors (6) connected to the control/regulation device. The storage tank is thermally insulated, closed from the atmosphere and subdivided into a liquid chamber (27) and a gas pressure chamber (28). The heating device and the temperature sensor are coupled to the liquid chamber in a thermally conducting manner and the pressure sensor is pneumatically coupled to the gas pressure sensor. An anesthetic gas outlet (10) comprising a flow throttle unit (12) is connected to the gas pressure chamber.

Description

Apparatus for providing anesthetic gas

The invention relates to a device for providing anesthetic gas according to the preamble of claim 1.

In inhalation anesthesia during surgical interventions anesthetic gas is added to fresh gas. The anesthetic gas may, for example, be isoflurane, secoflurane, desflurane, enflurane, halothane or diethyl ether, which is available in liquid form in commercial packaging.

Anesthesia devices are known in which fresh gas is partially passed through an evaporation vessel filled with liquid anesthetic and thereby accumulates with evaporating anesthetic. The metering takes place via a combination of a direct supply of fresh gas and a fresh gas supplied via the evaporation vessel. However, the dosage control is expensive here.

Furthermore, an arrangement used in a fresh gas line with a porous injection body is known, on one side of which liquid anesthetic is present and flows over the other side of fresh gas and mixes with evaporating anesthetic. The dosage is done via the feed setting of a syringe pump and is very inaccurate.

The invention has for its object to provide a device for providing anesthetic gas that provides saturated gas.

This object is achieved in a device according to the preamble of claim 1 by the features of this claim. Further developments and advantageous embodiments will become apparent from the dependent claims.

In the apparatus according to the invention, a storage container is at the same time part of an anesthetic evaporator and pressure generator. The heating ensures that the liquid anesthetic is heated above its boiling point and enforces forced evaporation. At the same time, a vapor pressure is formed, which is used to convey the narcotic gas that has now formed to the point of consumption. Since the evaporation takes place without any support of carrier gases, pure anesthetic gas is produced without the addition of carrier gas, which facilitates the dosage adjustment in the subsequent admixing with the fresh gas. Namely, the mixing ratio can then be adjusted exclusively via the ratio of the volume flow between fresh gas and anesthetic gas. A carrier gas content does not have to be considered in contrast to known embodiments.

In addition, an anesthetic gas already present in the gas phase can be metered more precisely than via the detour of the propulsion pump, in which only the delivery volume of the liquid phase can be adjusted.

About the temperature and / or pressure control of the heater by means of a temperature sensor and / or a pressure sensor, a constant delivery pressure of the anesthetic gas can be specified. It is also possible to adapt to different anesthetic agents with different boiling points and vapor pressures without hardware changes.

According to a development, the storage container consists of an anesthetic-resistant material or is internally coated with an anesthetic-resistant material. The anesthetics listed at the beginning have solvent properties which attack various plastics as well as metals, and this effect increases with increasing temperature.

By resistant materials or coatings, both the life of the reservoir itself and the downstream flow restrictor assembly is extended, since there can occur no clogging by detached components.

Furthermore, the flow restrictor arrangement may comprise at least one valve controlled by the control and regulating device.

Through this valve, there is the possibility of an additional influence on the delivery amount of anesthetic gas as part of the metering device. The inertia is much lower than with a control via the heater.

A first valve may be a proportional valve or a pulsed valve.

With both embodiments of the valves, a quasi-steady volume flow of the anesthetic gas can be adjusted.

Furthermore, a second valve may be an openable and closable safety valve.

Such a valve, especially in the medical sector, provides an important additional safeguard against anesthetic overdoses in the event of component failure, or in the event of a proportional or cyclic valve failure. According to a further development, level sensors can be arranged in the storage container and connected to the control and regulating device. These can then together with at least one controlled valve form a safety device against leakage of liquid anesthetic.

Since the device according to the invention is also suitable for mobile use due to the possibility of a very compact design, there is a risk in transporting a patient that the reservoir can occupy a position which is inappropriate in terms of the risk of leakage of liquid anesthetic and thus of overdosing of a patient is given theoretically. By the safety device such a state is detected in good time and turned off the device.

A further improvement provides an embodiment in which the gas pressure chamber is designed as a dome before the anesthetic gas discharge and in the dome additional level sensors are arranged and connected to the control and regulating device.

Through the dome, it is achieved that the storage vessel can assume larger tilt angles, without the risk of leakage of liquid anesthetic. The additionally arranged in the cathedral level sensors secure the case that even these increased tilt angle are exceeded.

The storage container can simultaneously be an anesthetic-filled commercial packaging and form a disposable storage container.

Such a design has the advantage that a particularly compact design is possible and the packaging required anyway for filling and shipping is shared. Alternatively, the reservoir may be a refill reservoir and having a fill port disposed in the fluid space connected to a filler.

With increased use and an associated increased need for anesthetic agents, this embodiment may prove more favorable.

The filling device preferably comprises a commercial packaging filled with anesthetic, to the nozzle of which an outlet line leading to the storage container and a compressed-air line coming from a gas supply unit are connected. In this case, a controllable valve, a liquid sensor and a temperature sensor are arranged in the outlet, which are connected to the control and regulating device. A control port of the gas supply unit is also connected to the control and regulating device.

As a result, the reservoir can be refilled with anesthetic if necessary. The refilling takes place here directly from the commercial packaging as needed.

The invention will be explained with reference to exemplary embodiments, which are illustrated in the drawing.

In drawing show:

1 shows a device according to the invention with refill option for feeding a respiratory system with anesthetic gas,

Fig. 2 shows an embodiment of the device as a disposable reservoir

Fig. 3 shows an embodiment of a reservoir with a dome and 4 and 5 representations of the reservoir in different tilting inclinations.

The device shown in Figure 1 a conveying and metering device 1 consists essentially of a reservoir 3, a controlled by a control and regulating device 9 heater 5 and connected to the control and regulating device 9 temperature sensor 8. The reservoir 3 is provided with a Heat insulation 4 jacketed and sealed to the atmosphere. Furthermore, the storage container 3 is subdivided into a liquid space 27 and a gas pressure space 28. In liquid space 27 is liquid anesthetic 2, while in the gas pressure chamber 28, the vaporized portion of the anesthetic is anesthetic gas. From the gas pressure chamber 28, an anesthetic gas discharge 10 with a flow restrictor arrangement of a safety valve 11 and a controllable valve 12 leads to a consumer, shown here as a microcirculation system 25 and patient 26th

In the gas pressure chamber 28 there is a pressure sensor 6 and in the anesthetic gas discharge 10 a flow sensor 13, which are also connected to the control and regulating device 9.

Liquid anesthetic 2 is heated by the heater 5 and evaporated. In the gas pressure chamber 28 is then anesthetic gas with an overpressure. The pressure could be determined once by knowing the parameters of the anesthetic via the temperature sensor 8, as direct pressure but also via the pressure sensor 6. With a fixed flow restrictor arrangement, a volume flow in the outlet conduit 10 could already be determined as a function of the pressure of the anesthetic gas , However, the flow sensor 13 determines a volume flow directly and can, depending on a set value, the actual volume flow rate. current via the control and regulating device 9 and the proportional valve or clocked valve 12 set.

About level sensors 7, the level can be monitored and controlled by the control and regulating device 9 are adapted from a filling device.

In addition, the level sensors 7 in conjunction with the control and regulating device 9 and the safety valve 11 form a safety device against leakage of liquid anesthetic.

If the storage container 3 is inclined and threatens to leak liquid anesthetic 2 directly through the anesthetic gas discharge 10, this is detected by the level sensors 7 and then the safety valve 11 is closed.

For refilling is a filling device consisting of a filled with anesthetic 15 commercial packaging 14. At its spout a leading to the reservoir 3 outlet 16 and a coming from a gas supply unit 20 compressed air line 23 is connected. In the outlet line 16 are a controllable valve 19, a liquid sensor 17 and a temperature sensor 1, which are all connected to the control and control unit 9. A control connection of the gas supply unit 20 is also connected to the regulation and control unit 9. By the arranged in the reservoir 3 level sensors 7, the level is monitored. If the level is too low, the valve 19 is opened so that anesthetic 15 can flow from the commercial packaging 14. In addition, if the discharge pressure is insufficient, the gas supply unit 20 is turned on.

This consists of a pump 21 and a suction filter 22. In addition, a control valve 24 is still arranged in the pressure line 23. The in the outlet 16 The temperature sensor 18 determines the temperature of the inflowing liquid anesthetic so that by appropriate control of the heater 5, the boiling point of the anesthetic 2 in the reservoir 3 again quickly reached becomes.

In the illustration according to FIG. 2, the device comprises a storage container 32, which at the same time is an anesthetic-filled commercial packaging and a disposable storage container. This embodiment corresponds to that of Figure 1 with the exception of the filling connection and the filling device.

In the representation of a storage container 3 shown in FIG. 3, the gas pressure space 28 is formed before the anesthetic gas discharge 10 as a dome 30, a central gas channel being arranged between the dome 30 and the remaining part of the gas pressure space 28. In Dom 30 more level sensors 7 are arranged. Furthermore, there is still a semipermeable membrane 31 above the dome 30 as additional protection against liquid leakage into the outlet duct 10.

The further Figures 4 and 5 show the same arrangement, as shown in Figure 3, but not in a vertical orientation, but in a tilted orientation.

4 shows a tilted position in which liquid anesthetic 2 only penetrates into the gas pressure chamber 28 below the dome 30. In this position, a closure of the safety valve 11 can still be dispensed with.

FIG. 5, on the other hand, shows a more critical tilting position, in which anesthetic 2 has also penetrated into the dome 30. In this case, the level sensors 7 arranged in the dome 30 respond and close the safety valve 11. In the event that the safety valve 11 should also fail, the semipermeable membrane 31 allows an unimpeded transfer of liquid anesthetic into the outlet line and thus a strong overdose of a patient with anesthetic.

Claims

Patent claims

1. A device for providing anesthetic gas, comprising a storage container and a conveying and metering device, characterized in that the conveying and metering device comprises a temperature-controlled anesthetic evaporator and pressure generator which generates saturated anesthetic agent vapor and this without supply of fresh external or transport gas is made available to a dosing system by its own vapor pressure via an outlet line, consisting of the reservoir (3) itself, a heater (5) controlled by a control and regulating device (9) and a control device ( 9) associated temperature (8) and / or pressure sensor (6), wherein the reservoir (3) thermally insulated, closed to the atmosphere and in a liquid space (27) and a gas pressure chamber (28) is divided, and wherein the heater (5) and the temperature sensor (8) are thermally conductively coupled to the liquid space (27) and the pressure sensor (6) pne is coupled umatisch with the gas pressure chamber (28) and to the gas pressure chamber (28) an anesthetic gas outlet line (10) is connected to a flow restrictor arrangement.

2. Apparatus according to claim 1, characterized in that the storage container (3) consists of a, even at elevated temperature, anesthetic-resistant material or is internally coated with a corresponding anesthetic-resistant material.

3. Device according to claim 1 or 2, characterized in that the flow restrictor arrangement comprises at least one of the control and regulating device (9) controlled valve (12).

4. Device according to one of claims 1 to 3, characterized in that a first valve (12) is a proportional valve or clocked valve.

5. Device according to one of claims 1 to 4, characterized in that a second valve (11) is an openable and closable safety valve.

6. Device according to one of claims 1 to 5, characterized in that arranged in the reservoir (3) level sensors (7) and these are connected to the control and regulating device (9) and together with at least one controlled valve (11) a safety device against leakage of liquid anesthetic (2).

7. Device according to one of claims 1 to 6, characterized in that the gas pressure chamber (28) before the anesthetic gas discharge (10) as a dome (30) is configured in the dome (30) additional level sensors (7) and arranged with the control and Regulating device (9) are connected.

8. Device according to one of claims 1 to 7, characterized in that the storage container (3) is at the same time an anesthetic filled commercial packaging and disposable storage container.

9. Device according to one of claims 1 to 7, characterized in that the storage container (3) is a Nachfüllvorratsbehälter and in the liquid space (27) arranged filling port, which is connected to a filling device.

10. The device according to claim 9, characterized in that the filling device comprises an anesthetic agent (15) filled commercial packaging (14), at the nozzle of a spout to the reservoir (3) leading outlet (16) and one of a gas supply unit (20) coming compressed air line (23) is connected, wherein in the outlet line (16) a controllable valve (19), a Liquid sensor (17) and a temperature sensor (18) are arranged, which are connected to the control and regulating device (9) and a control terminal of the gas supply unit (20) is also connected to the control and regulating device (9).