DE102004011907A1 - Artificial narcosis respiration unit presents the drive gas for the dome, or for the dome and the control chamber of an overflow valve, with use of a double valve consisting inhalation and exhalation valves - Google Patents

Abstract

The artificial narcosis respiration unit presents the drive gas for the dome (1), or for the dome and the control chamber of an overflow valve (15), with use of a double valve (3) consisting of inhalation and exhalation valves (4, 5). The unit further includes valves (22, 23) for switching the unit between narcosis and therapy modes of operation.

Description

object The invention is the anesthesia ventilation technique.

To In the prior art, the pneumatic system in anesthesia ventilators in the Majority of cases from two pneumatically separated circles: the drive gas circuit and the patient group. The drive gas is a cylindrical Casing, supplied to the so-called dome, in which there is a bellows (drive gas circuit). The through the driving gas exerted in the cathedral Print transfers on the inside of the bellows. This is about the breathing tubes with connected to the patient's lung and forms the breathing circuit. Of the Bellows provides as long as he is not at the bottom or top Limitation within the dome rests, the separation point between in both circles, for that ensures that between two circles almost pressure equilibrium prevails.

So corresponds to a pressure change in the drive gas circuit very well with an almost equal pressure change in the patient group. The same applies to a volume change.

The Control of pressure and / or volume in the breathing circuit is accordingly by controlling pressure and / or volume in the drive gas circuit causes as long as the breathing bellows is not at a limit.

A Inspiration is triggered by the fact that the drive gas compresses the breathing bellows and thereby inspiratory gas transported to the lungs. While the expiration fills the exhaled gas of the patient resumes and moves the bellows make him up.

Of the Bellow has an upper and a lower limit. Is he at the lower limit, so he can not continue through the drive gas pressed together and thus can by the driving gas no further inspiratory pressure increase exercised the patient group become. When reaching the upper limit, the patient can no longer exhale freely: the end-expiratory pressure increases. Around To avoid this is in the patient circuit, a so-called overflow valve provided over which excess breathing gas to flow into the outdoors can.

This overflow valve is usually designed as a pneumatically controllable 2-2-way valve.

Of the Positive end-tidal pressure (PEEP) is generally transmitted through creates a PEEP valve, which in Exspirationszweig before the bellows is arranged.

you distinguishes between ventilation in open ventilation during anesthesia ventilation System, semi-open and closed system.

at Ventilation in a closed system gives the patient his inspiratory air from the breathing gum. The expired air returns via a CO2 absorber back in the breathing gum. The oxygen consumption is by introducing fresh gas compensated.

at Ventilation in the open system flows the exhaled air of the patient via the overflow valve into the open.

The Control of the ventilation pressure itself takes place via the control of the drive gas pressure. In known methods flows the drive gas as a constant volume flow of a parallel arrangement from Dom and a controllable valve too. The latter is so controlled that just the desired pressures Set Pmax and PEEP in the dome. The excess drive gas flows into the Free, associated with a significant gas loss.

at another known solution the control of the ventilation pressure is effected by motor drive of the Balges, which trigger both inspiration and expiration can.

Furthermore, a solution in therapy ventilators is known in which the control of the respiratory gas for a patient by a so-called double valve ( DE 4345123 C1 ). This contains two controllable valve resistors, which can be adjusted in opposite directions. Opens the inspiratory valve, closes the exhalation valve and vice versa. The advantage of this solution is the low gas consumption, since the inspiratory volume flow is fully supplied to the patient and there is only a small loss of gas compared to the method described above with a constant volume flow. In addition, the mechanical control is particularly simple because of the coupling of the two valve pistons. By arranging an injector in series with the expiratory valve, one is additionally able to produce a negative pressure as well.

A disadvantage is always felt by the anesthetists that there is no possibility of using the anesthesia ventilator as an intensive care ventilator or at least a short-term use as a normal ventilator, in order to make the transition to Intensivbeat easier to facilitate. The combination of both types of devices in one device would be very desirable.

in addition that comes for it Certain operations in the thoracic area is helpful, the thorax to calm down. Therefor High frequency ventilation has proven itself, but still a second ventilator require. The additional implementation This form of ventilation in the anesthesia ventilator would be of great advantage to the anesthetist.

• • dass die Steuerung sehr träge ist,
• • dass sie bezüglich des zu beatmenden Patientenbereiches (vom Säugling bis zum Erwachsenen) eingeschränkt sind,
• • dass Sie keine Möglichkeit der Kombination von einem Narkosebeatmungsgerät und einem Intensivbeatmungsgerät gestatten und
• • dass sie keine Möglichkeit der Applikation hochfrequenter Beatmungsformen erlauben.

All current solutions for anesthesia ventilator have the disadvantage

• • that the controller is very sluggish,
• • that they are restricted in terms of the patient area to be ventilated (from the baby to the adult),
• • that you do not allow a combination of anesthesia ventilator and an intensive care ventilator, and
• • that they do not allow the possibility of applying high-frequency forms of ventilation.

task The invention therefore is to find such a solution for an anesthesia ventilator, which avoids the described disadvantages of the devices of the prior art.

These Task is inventively characterized solved, that the known double valve with injector in a novel Application used to control the drive gas of anesthesia ventilator becomes. additionally the double valve also controls the control chamber of the overflow valve.

By the parallel arrangement of Dom in the pneumatic sense on the one hand and control chamber of the overflow valve On the other hand, one is able, with only one valve, the patient's pressure to regulate precisely both in the open and in the closed system, especially if the double valve as an actuator within a control loop for the ventilation pressure at the Y-piece serves as a controlled variable. control loops same configuration, but with the flow from and to the patient, the tidal volume or the respiratory minute volume as a controlled variable equally possible. Other control structures such as cascade control with pressure control as inner loop and volume flow or volume control as outer loop are particularly advantageous forms of regulation.

Of the Advantage of this solution according to the invention is that thus a very fast regulation in a wide range of patients, from the premature baby to reach the adult.

One Another advantage is that the PEEP valve can be omitted, as its Function once by the pressure control via the control pressure in the cathedral as well over taken over the control chamber of the overflow valve becomes.

Advantageous in this solution is still that because of the low inlet pressure of the double valve on the inspiratory side of about 150 mbar also simple turbines for the Have drive gas supply installed. This one is independent of the high-pressure gas supply, which in particular for the mobile operation is very cheap.

is the bellows due to an excessive fresh gas flow end expiratory in its upper limit, could Do not exhale the patient further. In this case, the pressure drops in the control chamber of the overflow valve through opening of the expiratory part of the double valve so far that the overflow valve opens and the excess gas to flow into the outdoors can. In this case receives you a big one negative pressure difference between the control pressure Pst and the pressure on the Y-piece Py.

is the bellows, on the other hand, are inspired by a too low fresh gas flow in its lower limit, the device can not provide inspiratory pressure exercise more. In this case, the pressure in the control chamber of the overflow valve increases through opening of the inspiratory part of the double valve. In this Case gets you have a big positive one Pressure difference between the control pressure Pst and the pressure at the Y-piece Py.

Consequently is the pressure difference between control pressure Pst and ventilation pressure Py is an important indicator of the position of the bellows within the dome, on the one hand as a hint or warning about change the fresh gas flow can be used by the operator and on the other hand also for an automatic fresh gas adjustment in the form of a slow control loop, so that the bellows always within the limits and thus is in an optimal position.

The entire pneumatic system is so fast that high ventilation frequencies can be achieved in both open and half-open or closed systems. Since flow through the double valve volume flows in an order of magnitude, which can also be used directly for the ventilation of a patient, a switchover is provided according to the invention in a further advantageous embodiment of the invention, via which the patient can be ventilated directly from the double valve. On the one hand, this has advantages for certain te operations, z. B. in the thoracic surgery, because it can thereby administer bypassing the relatively lethargic breathing very fast forms of ventilation such as high-frequency oscillation, on the other hand, it has created a way of combining anesthesia ventilator with a normal therapy ventilator, with appropriate equipment as an intensive care ventilator.

These switchover is in the form of two switching valves for the operating modes anesthesia ventilator-therapy ventilator, which are switched simultaneously and in the one switching position (normally the OFF position) the outputs of both part valves of the Double valve connect together and in the manner described with the control input of the overflow valve on the one hand and the entrance of the cathedral on the other hand. In the other Switching position (usually the ON position) represents the inspiratory Mode switching valve the connection from the outlet of the inspiratory valve of the double valve to the inspiratory outlet (beginning of the inspiration tube) and the expiratory mode change-over valve the connection from the exit of the exhalation valve to the expiratory outlet of the equipment (Beginning of the expiratory tube) ago.

at This arrangement is in the ON position of both mode changeover valves the retroactive effect of the inspiratory flow rate to the interior of the bellows by the usual provided one-way inspiratory valve prevented. The expiratory flow However, after passing the expiratory one-way valve as well the switching valve for open and closed mode of operation (hereinafter "changeover valve Open-Closed ") in principle the possibility, to divide once over the exhalation valve of the double valve and on the other hand via the Absorber back in the Balginnere. Because of the pressure equality this will not happen. To be sure, therefore, another check valve between Changeover valve open-closed and provided the absorber, to this backflow into the Bellows during to prevent expiration. It is of course possible to use this check valve between all members within the chain of effects, starting with the exsp. One way valve over but to arrange the switching valve open-closed, the absorber and the dome the previously indicated arrangement is preferable. In which valve position, ON or OFF the desired Functions are in themselves irrelevant. Because of the primary use of the device as anesthesia machine however, the described assignment makes sense. It is the same irrelevant whether the said valves pneumatic or electronic be controlled. decisive alone is the way it works.

The When used as a therapy ventilator, respiratory gas is supplied via the Driving gas, which in order to achieve a higher oxygen concentration also over a belonging to the prior art Breathing gas mixer can be provided. Moistening takes place either over one artificial Nose or a commercially available breathing gas humidifier, which is inserted into the inspiratory tube.

In Another embodiment of the invention is the fresh gas supply used in conjunction with the volume of the dome a reservoir for a desired Create breathing gas mixture, from which the form input of the Inspiratory valves can be operated. Such a solution is simplified because of the high bellows volume the breathing gas mixture. This solution is especially useful if the breathing gas mixture is done by switched valves, because thereby the switching frequency of the valves can be reduced.

at this solution will over another switching valve for the drive gas is the admission pressure inlet of the inspiration valve of the Double valve switched between the drive gas source (OFF position) on the one hand and the bellows on the other hand (ON position). Important is, that the valve positions of all three valves, the mode changeover valves and match the drive gas switching valve. The bellows gets the breathing gas mixture from the Frischgasbereitstellung and ensures his volume for a very good mix. He feeds in the ON position of the Drive gas switching valve the dual valve with the therapeutic Breathing gas mixture.

Very Cheap it is when the normally used to measure the control pressure Input of a pressure sensor via a measuring pressure changeover valve is made switchable, so he either measure the control pressure in the dome (normal state) or the pressure in the bellows can. In the latter case, the pressure sensor is used for actual value detection the bellows pressure, which in conjunction with the within the fresh gas supply located valves forms a control circuit for keeping constant the bellows pressure.

It but it is also possible the fresh gas supply in case of use as a therapy ventilator directly over Additional valve to connect to the input of the inspiratory valve.

If one wants to use only the inventive advantage of the control of the drive gas through a double valve, one could finally on the parallel control of the control chamber dispense with the double valve and make this control in another way.

The invention will be explained below with reference to an embodiment which is described in 1 is shown.

The double valve 3 consists of the inspiratory valve 4 and the expiratory valve 5 whose valve pistons are firmly connected to each other and both in opposite directions via the drive 6 to be controlled. The inspiration valve 4 is from an associated drive gas source 20 with a positive pressure of about 150 mbar and the expiratory valve 5 via an injector 21 subjected to a negative pressure of about -30 mbar. The amount of these pressures is not decisive. It depends on the valve geometry.

Depending on the position of the double valve 3 air flows into the cathedral 1 into (inspiration) or gets out of the cathedral 1 sucked out (expiration).

This lowers the bellows 2 at inspiration, or he rises in case of expiration.

In the case of inspiration, the breathing gas flows out of the bellows 2 about the insp. one-way valve 8th and the inspiratory tube 26 to the Y-piece 9 and thus to the patient's lungs 10 , During expiration, the patient breathes over the expiratory tube 27 and the exsp. one-way valve 11 out.

In the closed system, the changeover valve is open-closed 12 switched on and the expired air passes from the Y-piece 9 , the expiratory tube 27 that exsp. one-way valve 11 , the switching valve open-closed 12 and over the absorber 13 back to the cathedral 2 ,

In the open system (changeover valve open-closed 12 is de-energized), however, the exhaled air of the patient exsp. one-way valve 11 via the valve changeover valve open-closed 12 to the overflow valve 15 and from there into the open air. Through the one-way valve 14 Prevents the expiratory gas from entering the bellows again 2 flowing back.

The fresh gas flows from the fresh gas supply 7 also in the bellows 2 ,

The overflow valve 15 is a controlled valve, which has an additional control input to the common output of the double valve 3 connected is.

The control circuit for the ventilation pressure is formed by the entire previously described pneumatic system and the pressure sensor ventilation pressure 16 to measure the pressure on the Y-piece and the regulator 17 that evaluates the control deviation according to its control algorithm and the drive 6 for the double valve 3 controls accordingly.

The pressure sensor control pressure 18 is used to measure the control pressure Pst. By comparison with the ventilation pressure measured on the Y-piece in the assessment unit 19 If a certain predetermined pressure difference is exceeded or undershot, a warning signal is generated for the user. In a particularly favorable embodiment, symbolized by the dashed line of the evaluation unit 19 for fresh gas supply 7 , the fresh gas flow is changed by the evaluated pressure difference signal in a slow control loop so that the bellows 2 always in the optimal location.

In 2 is shown a solution in which the device can be used both as anesthesia ventilator and as a respiratory therapy device. The latter application is particularly interesting when it is desired to immobilize the body for certain operations in the neck or thoracic region. Here, the high-frequency oscillation is a approved method. In addition, this solution also opens up the possibility of normal therapeutic ventilation. For the sake of clarity, only the essential elements required for the switching function are shown.

The connection between the inspiratory valve 4 and the expiratory valve 5 of the double valve 3 is disconnected and the output of inspiratory valve 4 on the entrance of the insp. Mode switching valve 22 as well as the exit of expiratory valve 5 on the entrance of exsp. Mode switching valve 23 placed. For de-energized mode changeover valves 22 and 23 are both outputs of the part valves 4 and 5 of the double valve 3 connected in the manner already described and control dom and overflow in parallel. When the insp. Mode switching valve 22 this connects the inspiratory valve 4 with the inspiratory output of the device after the insp. one-way valve 8th , In the same way, the exsp. Mode switching valve 23 the exit of the expiration valve 5 with the exhalation outlet of the device after exsp. one-way valve 11 , This can be done by switching the operating mode changeover valves 22 and 23 between anesthesia ventilation (both valves are off) and normal therapeutic ventilation (both valves are on). In the latter case, provide additional respiratory gas humidification, either through an artificial nose 24 after this Y-piece or an active humidifier 25 who, in a familiar way, enters the inspiratory direction 26 is inserted done. Because of the pressure equality, the connection must be via the one-way valve 11 , the valve 12 and the absorber 13 not be separated. If necessary, this path can be found in the in 3 way described by a check valve 29 additionally blocked.

The drive gas source 20 In this embodiment, it must be able to generate a respiratory gas with an adjustable oxygen concentration.

3 shows a particularly favorable embodiment of the invention, in which the fresh gas production 7 at the same time the provision of the breathing gas mixture in the case of use as a therapy device and the bellows 2 is used as an additional volume for the breathing gas mixture. About the drive gas switching valve 28 the switchover of the inlet pressure input of the inspiration valve takes place 4 between the drive gas source 20 on the one hand (OFF position) and the bellows 2 on the other hand (ON position). So now puts the pressure in the bellows 2 with the desired oxygen concentration the required form for the double valve 3 ready. The check valve 29 ensures that in the case of operation as a therapy device neither the expiratory gas to the bellows 2 still air from the bellows 2 can flow to the expiratory outlet. The function of the two changeover valves 12 and 29 can also be replaced by a known in the art 3-3-way valve.

So that the pressure in the bellows 2 can be kept constant, via the pressure sensor 18 in conjunction with the internal valves of Frischgasbereitstellung a pressure control circuit for the output pressure of the fresh gas supply 7 and thus the form for the double valve 3 realized. For this purpose, the pressure sensor 18 via the pressure sensor changeover valve 30 to the feed line to the bellows 2 turned on. When operating as an anesthetic ventilator, the pressure sensor switching valve switches 30 the pressure sensor 18 to the feeders for the cathedral 2 for measuring the dome internal pressure. The valuation unit 19 is not shown in this figure. It is analogous to 1 to take into account.

1

cathedral

2

bellows

3

double valve

4

inspiration valve

5

expiratory

6

valve drive

7

Fresh gas supply

8th

insp. one-way valve

9

Y-piece

10

lung of the patient

11

exp. one-way valve

12

switching valve Open closed

13

absorber

14

one-way valve

15

overflow

16

pressure sensor ventilation pressure

17

regulator

18

pressure sensor control pressure

19

assessment unit

20

Drive gas source

21

injector

22

insp. Mode switching valve

23

exp. Operating mode changeover valve

24

artificial nose

25

humidifier

26

inspiration tube

27

expiratory

28

Drive gas switching valve

29

check valve

30

Pressure sensor switch valve

31

additional valve

Claims (11)

Anesthesia ventilator, in particular consisting of a bellows ( 2 ) located within a dome ( 1 ), one-way valves ( 14 ) 8th ) and ( 11 ), an absorber ( 13 ), a switching valve open-closed ( 12 ), a Y-piece ( 9 ) as well as a fresh gas supply ( 7 ), characterized in that the drive gas for the dome ( 1 ) or for the cathedral ( 1 ) and for the control chamber of a spill valve ( 15 ) of a double valve ( 3 ), consisting of an inspiratory valve ( 4 ) and an expiratory valve ( 5 ), which in the inspiratory branch is supplied by a positive admission pressure and in the expiratory branch by a negative admission pressure, which if necessary, in an advantageous embodiment, operating mode changeover valves ( 22 ) and ( 23 ), via which the switchover from the anesthesia ventilator to the therapeutic ventilator takes place. Anesthesia ventilator according to claim 1, characterized in that the double valve ( 3 ) as an actuator of a control loop for a controlled variable, such. B. the ventilation pressure or the tidal volume or the flow rate of breathing. Anesthesia ventilator according to claim 1 or 2, characterized in that for switching between the operating mode anesthetic ventilator or therapy ventilator, the output of the inspiratory valve ( 4 ) with the entrance of the insp. Mode changeover valve ( 22 ) and the exit of the exhalation valve ( 5 ) with the entrance of exsp. Mode changeover valve ( 23 ) are connected, wherein in the operating mode of the anesthesia ventilator associated switching position of both mode switching valves ( 22 ) and ( 23 ) the first output of the insp. Mode changeover valve ( 22 ) with the first exit of exsp. Mode changeover valve ( 23 ) as well as the entrance of the cathedral ( 1 ) and the control input of the overflow valve ( 15 ) are connected, and in the operating position of the therapy ventilator associated switching position of both operating mode changeover valves ( 22 ) and ( 23 ) the second output of the insp. Mode changeover valve ( 22 ) with the inspiratory output of the device after the insp. One-way valve ( 8th ) and the second exit of exsp. Mode changeover valve ( 23 ) with the expiratory outlet of the device after exsp. One-way valve ( 11 ) are connected. Anesthesia ventilator according to one of claims 1 to 3, characterized in that, for the purpose of preventing the return of respiratory gas into the bellows ( 2 ) additionally a check valve ( 29 ) between two adjacent elements to be selected within an action chain formed from the exsp. One-way valve ( 11 ), the switching valve open-closed ( 12 ), the absorber ( 13 ) and the bellows ( 2 ) is inserted. Anesthesia ventilator according to one of claims 1 to 4, characterized in that for the purpose of using the fresh gas supply ( 7 ) for therapeutic ventilation of the inlet pressure of the inspiratory valve ( 4 ) via an additional valve ( 31 ) with the output of the fresh gas supply ( 7 ) connected is. Anesthesia ventilator according to one of claims 1 to 5, characterized in that for the purpose of using the fresh gas supply ( 7 ) for therapeutic ventilation of the inlet pressure of the inspiratory valve ( 4 ) via a drive gas switching valve ( 28 ) either with the drive gas source ( 20 ) or with the bellows ( 2 ) connected is. Anesthesia ventilator according to claim 5 or 6, characterized in that for the purpose of keeping the pressure of the fresh gas in the bellows ( 2 ) the input of the pressure sensor ( 18 ) via a pressure sensor switching valve ( 30 ) when used as anesthesia device with the dome ( 1 ) and when used as a respiratory therapy device with the bellows ( 2 ), and the output of the pressure sensor ( 18 ) with the internal valves of the fresh gas supply ( 7 ) forms a control loop which determines the output pressure of the fresh gas supply ( 7 ) keeps constant. Anesthesia ventilator according to one of claims 3 to 7, characterized in that when used as anesthesia ventilator to ensure additional Atemgasanfeuchtung either an artificial nose ( 24 ) is provided after the Y-piece or an active humidifier ( 25 ) is inserted into the inspiratory line in a known manner. Anesthesia ventilator according to one of claims 1 to 8, characterized in that when used as anesthesia ventilator the difference between the control pressure Pst and the ventilation pressure Py a warning signal generated when this difference is an upper positive or a exceeds the lower negative limit. Anesthesia ventilator according to one of claims 1 to 8, characterized in that when used as anesthesia ventilator, the difference between the control pressure Pst and the ventilation pressure Py as a control variable for a Control loop is used, in which the fresh gas flow is regulated so that the bellows is always in the optimal area inside the dome. Anesthesia ventilator according to one of claims 1 to 10, characterized in that the drive gas source ( 20 ) is formed by an air turbine.