DE102008051515B4 - ventilator - Google Patents

Abstract

Ventilator (9) for the artificial respiration of a patient (7), comprising - a gas delivery device (2), - at least one gas line (10) for forming a breathing air system (36), in particular a breathing air circuit (37), - in the gas line (10 ) arranged first check valve (4) for forming an inspiratory gas line (5) as part of the gas line (10), - in the gas line (10) arranged second check valve (9) for forming an expiratory gas line (8) as part of the gas line (10) , - a patient connection piece (6) connected to the inspiratory and expiratory gas line (5, 8), means for obtaining a residual pressure in the patient connection piece (6) and the expiratory gas line (8) during an expiratory phase, characterized in that the atmospheric pressure is at a Pressure sensor is detected and a control and / or regulation of the flow rate of the gas conveyor (2) is arranged to w During the expiration phase, the residual pressure is controlled and / or regulated to a value greater than the atmospheric pressure, the residual pressure being controlled and / or regulated exclusively by means of a control and / or regulation of the delivery flow of the gas delivery device (2) during the expiration phase and wherein an increase in the flow rate of the gas conveyor (2) leads to an increase in the residual pressure and a reduction in the flow rate of the gas conveyor (2) leads to a reduction of the residual pressure.

Description

The present invention relates to a ventilator according to the preamble of claim 1.

For various medical applications, eg. As in operations, artificial ventilation of patients is necessary. Ventilators are used for artificial ventilation of patients and may be designed as anesthesia machines to enrich the inspiratory gas with anesthetics. In some ventilators, at least in part, the exhaled expiratory gas exhaled by the patient may be reused as inspiratory gas, i. H. It is a rebreathing system with a breathing air circulation system.

In the respirator with the breathing circuit a gas delivery means is provided which directs the breathing air to the patient during inspiration. During and after the exhalation, the gas conveyor is either switched off or is operated only with a very low flow. For medical reasons, it is necessary that, during and after exhalation, there be a residual pressure greater than atmospheric pressure on a patient fitting connected to the patient. B. by more than 5 mbar. The residual pressure (PEEP: positive end expiratory pressure) is regulated by a PEEP valve. The PEEP valve is located in a gas line of the breathing circuit. The PEEP valve has a piston moved by an electromagnet, which can release a different flow cross-sectional area. Due to this controlled variable flow cross-sectional area on the PEEP valve as a proportional valve, the required residual pressure is controlled during and after exhalation. Disadvantageously, the PEEP valve requires independent control and, due to the necessary force / current dependency, a high power loss, which is associated with a heating of the breathing gas conducted through the gas line. Furthermore, the PEEP valve is a large and heavy component, so that use of the ventilator with such a PEEP valve for near-patient ventilation, z. B. in an emergency or transport ventilator, is much more difficult. Furthermore, the PEEP valve is technically complex and therefore expensive to manufacture.

The DE 199 58 532 C1 shows a respirator with a breathing circuit in which a designed as a rotary compressor gas conveying element is arranged. On the output side, a first gas volume flow sensor with an associated first check valve is connected in an inspiratory manner to a patient connection piece. In the connecting line between the patient connection piece and the patient there is a second gas volume flow sensor. The patient connector is expiratory connected via a third gas flow sensor with an associated second check valve and a controllable check valve with a reversible Atemgasreservoir. In each expiration phase, the speed of the gas delivery element is reduced or turned off, the controllable check valve is opened and the expiratory gas flow is measured by the second gas flow sensor and the speed of the gas delivery element is controlled in response to the measurement signals of the first gas flow sensor. Disadvantageously, a check valve is required.

From the DE 197 14 644 C2 is a respiratory and anesthesia machine with a gas conveyor known. A centrifugal compressor as a gas delivery device does not deliver during exhalation of the patient, so that the exhaled expiratory gas exhaled by the patient flows into a gas storage volume and is available for the next inhalation stroke. The inhale gas passes through a check valve in the patient, provided that the pressure in an inspiratory and a control line is higher than in the patient's lungs, as in this state, a diaphragm presses a valve disc on a crater. As soon as the pressure ratio between the inspiratory line and the patient is reversed, either by reducing the speed in the centrifugal compressor or by the respiratory efforts of the patient, the valve disc opens and the patient can exhale via the check valve to the atmosphere.

Furthermore, the describes DE 691 32 030 a device for ventilating a patient, with which the respiratory system is subjected to an increased pressure continuously during the respiration (CPAP - Continuous Positive Airway Pressure). Essential for the described ventilation method is that during the expiratory phase, the pressure level in the respiratory system is lowered again by means of a targeted venting. A targeted and flexible variation of the pressure in the respiratory system even during the expiratory phase is not possible in the manner described.

The object of the present invention is therefore to provide a ventilator for the artificial respiration of a patient, in which the residual pressure can be controlled and / or regulated with little technical effort. Furthermore, the ventilator should be constructed inexpensively and compactly in the production.

This task is solved with a ventilator for the artificial respiration of A patient comprising a gas delivery device, at least one gas line for forming a breathing air system, in particular a breathing air circuit, a first check valve arranged in the gas line for forming an inspiratory gas line as part of the gas line, a second check valve arranged in the gas line for forming an expiratory gas line as part of the gas line, a patient fitting connected to the inspiratory and expiratory gas line, means for obtaining a residual pressure in the patient fitting and the expiratory gas line during an expiratory phase, the residual pressure being greater than the atmospheric pressure, the residual pressure being exclusively by means of controlling and / or regulating the flow rate of the gas delivery device during the exhalation phase is controlled and / or regulated, since an increase of the flow rate of the gas conveying device with an increase in the residual pressure v and vice versa due to the pneumatic resistance of the breathing air system.

The breathing system of the ventilator has a pneumatic resistance. The gas delivery device designed in particular as a radial compressor is controlled and / or regulated such that during or after the exhalation phase of the patient the required residual pressure or PEEP pressure in the patient connection piece and / or the expiratory line during the expiration phase or subsequently occurs. For an increase in the residual pressure, only the flow rate of the gas conveyor must be increased, so that thereby increases the pressure in the gas line due to the pneumatic resistance of the breathing air duct system. In a particularly advantageous manner, this does not require a complicated PEEP valve.

In a further refinement, a throttling device is installed in the at least one gas line, in particular the expiratory gas line in the flow direction downstream of the second non-return valve, in order to increase the pneumatic resistance of the respiratory air line system. The throttle body increases the pneumatic resistance of the breathing air system, so that during the expiratory phase, a lower flow rate of the gas conveyor is required to achieve the necessary residual pressure. The necessary, preferably electrical, energy for operating the gas delivery device during the expiration phase can thereby be reduced in an advantageous manner.

In particular, the flow cross-sectional area of the throttle element is less than 50% of the flow cross-sectional area of the at least one gas line.

In a supplementary embodiment, the pressure in the expiratory gas line can be detected by means of a first pressure sensor and, depending on the detected pressure during the expiration phase, the delivery flow of the gas delivery device can be controlled and / or regulated. The first pressure sensor detects the pressure in the expiratory gas line or the patient connector. This detected pressure is compared with the atmospheric pressure outside sensed by another corresponding atmospheric pressure sensor, and the control unit then controls and / or regulates the flow rate of the gas delivery means to achieve the desired residual pressure.

Preferably, by means of a second pressure sensor, the pressure in the inspiratory gas line can be detected and, depending on the detected pressure during the expiratory phase, the flow rate of the gas delivery device can be controlled and / or regulated. The second pressure sensor senses the pressure in the inspiratory gas line or the patient connector. This detected pressure is compared with the atmospheric pressure outside sensed by another corresponding atmospheric pressure sensor, and the control unit then controls and / or regulates the flow rate of the gas delivery means to achieve the desired residual pressure.

In a variant, the flow cross-sectional area of the throttle element, in particular pneumatically by means of the respiratory gas in the at least one gas line, to the effect that at an increasing pressure in the at least one gas line, the flow cross-sectional area of the throttle body is smaller and vice versa. During the inspiration phase, the gas conveyor is operated at a high flow rate. Due to the high flow rate during the inspiration phase occurs in the at least one gas line, a high pressure, whereby the flow cross-sectional area of the throttle body is smaller. As a result, a smaller amount of gas flows through the throttle body during the inspiration phase, so that during the inspiration phase, the gas conveying device can be operated with a lower flow, because a lesser part of the breathing gas or inspiration gas conveyed by the gas conveyor does not flow through the throttle body and thus also the expiratory gas line ,

A valve is expediently arranged in the expiratory gas line, in particular in the flow direction upstream of the throttle element, and during the inspiration phase the valve is closed and the valve is opened during the expiration phase. Because of during the inspiration phase When the valve is closed, no breathing air or inspiratory gas is passed through the expiratory gas line or throttling element, so that the entire flow of the gas delivery device provided during the inspiration phase is inhaled by the patient, thereby operating the gas delivery device at a lower flow during the inspiratory phase can. The valve is used exclusively for opening or closing the expiratory gas line, ie there is no control and / or regulation of the flow cross-sectional area of the valve possible or necessary, so that this is structurally simple and inexpensive to manufacture.

The method for artificial respiration of a patient by means of the ventilator according to claims 1 to 8, is passed through at least one gas line of a breathing air system by means of a gas conveyor breathing air through a patient connector, the patient inspiratory and expiratory gas on and exhales during the inspiration phase the Gas conveyor is operated at a higher flow rate than during the expiratory phase, the residual pressure exhaled by the patient exhaled expiratory gas in the at least one gas line of the breathing air control system is regulated and / or controlled, wherein the residual pressure is greater than the atmospheric pressure, characterized in that the residual pressure is controlled and / or regulated by means of a control and / or regulation of the delivery flow of the gas delivery device during the expiratory phase.

In particular, the residual pressure is controlled and / or regulated exclusively by means of a control and / or regulation of the delivery flow of the gas delivery device.

In a further embodiment, the pneumatic resistance, in particular of the exhalation gas during exhalation, is increased by a throttle element in the at least one gas line.

In a supplementary variant, the change in pressure of the respiratory gas caused by the throttling element, with a deviation of less than 30% in the second or third power, depends on the volume flow of respiratory gas conducted through the throttling element.

In a further variant, the flow cross-sectional area of the throttle element, in particular during the expiration phase, is changed, and as the pressure in the at least one gas line increases, the flow cross-sectional area of the throttle element becomes smaller and vice versa.

In a further embodiment, the pressure in the at least one gas line, in particular in an expiratory and / or inspiratory gas line, detected and controlled depending on the detected pressure, the flow rate of the gas conveyor and / or regulated to control the residual pressure during the expiratory phase and / or to regulate.

In particular, the atmospheric pressure is detected and the residual pressure is controlled and / or regulated during the expiratory phase, so that the residual pressure is greater than the atmospheric pressure, for. B. the residual pressure by more than 2 mbar is greater than the atmospheric pressure.

The invention further includes a computer program having program code means stored on a computer-readable medium for carrying out a method as described above when the computer program is executed on a computer or a corresponding computing unit.

A component of the invention is also a computer program product with program code means which are stored on a computer-readable data carrier in order to carry out a method described above when the computer program is executed on a computer or a corresponding computing unit.

Hereinafter, embodiments of the invention will be described in more detail with reference to the accompanying drawings. It shows:

1 a highly schematic representation of a ventilator in a first embodiment,

2 a first diagram with a volumetric flow (flow) plotted on the abscissa and pressure drop (delta p) plotted on the ordinate,

3 an illustration of the ventilator according to 1 in a second embodiment,

4 an illustration of the ventilator according to 1 in a third embodiment,

5 an illustration of the ventilator according to 1 in a fourth embodiment;

6 a second diagram with a volumetric flow (flow) plotted on the abscissa and pressure drop (delta p) plotted on the ordinate,

7 an illustration of the ventilator according to 1 in a fifth embodiment,

8th an illustration of the ventilator according to 1 in a sixth embodiment and

9 an illustration of the ventilator according to 1 in a seventh embodiment.

In 1 is schematically a ventilator 1 in a first embodiment for the artificial respiration of a patient 7 shown. gas lines 10 of the ventilator 1 form as a Atemluftkreissystem 37 trained breathing air system 36 that is, the exhaled expiratory gas exhaled by the patient is reused as inspiratory gas for rebreathing. In an embodiment, not shown, the ventilator 1 Also be designed to the effect that the expiratory gas is discharged into the atmosphere and is used as the inspiration gas only air from the environment or the atmosphere, ie thus not the expiration gas is at least partially reused as inspiration gas. The ventilator 1 may also include an anesthetic reflector (not shown).

The breathing air is by means of a gas conveyor designed as a radial compressor 2 through the gas pipes 10 passed in a circle system. In the gas line 10 is a first inspiratory check valve 4 and a second, expiratory check valve 9 arranged. This forms an expiratory gas line 8th and an inspiratory gas line 5 as part of the gas pipes 10 out. At the end of the inspiratory and expiratory gas line 5 . 8th is a Y-piece 35 connected by means of a patient connector 6 the inspiratory and expiratory gas to a patient 7 passes. A CO ₂ absorber 11 absorbs the CO ₂ contained in the expiratory gas. Furthermore, oxygen is supplied to the expiratory gas by means of a feed device, not shown, to that of the patient 7 replace used oxygen. A hand-held breathing bag 3 is used for additional manual artificial ventilation of the patient 7 , One at the expiratory gas line 8th arranged first expiratory pressure sensor 32 detects the pressure in the expiratory gas line 8th , One at the inspiratory gas line 5 arranged second inspiratory pressure sensor 33 detects the pressure in the inspiratory gas line 5 ,

By means of a throttle body 13 with housing is the pneumatic resistance of the breathing circuit 37 elevated. In the throttle body 13 is a blind 14 arranged with an opening. A flow cross-sectional area of the throttle body 13 ie the area of the aperture of the aperture 14 , is less than 50% smaller than the flow cross-sectional area of the gas line 10 , For example, the opening of the aperture 14 circular and has a diameter of 5 mm. The gas line 10 is also preferably circular in cross-section and has a diameter in the range of 20 mm. The flow cross-sectional area for the through the Atemluftkreissystem 37 Guided breathing gas is thus on the throttle body 13 significantly reduced, causing a pressure drop 12 Delta p on the throttle body 13 established. In the gas line 10 Forms before and after the throttle body 13 a turbulence region, so that the pneumatic resistance or the pressure change delta p approximately square of that by the throttle body 13 directed volumetric flow of respiratory gas depends.

In 2 is in a first diagram on the abscissa of the flow through the throttle body 13 directed breathing gas in l / min indicated. The ordinate shows the pressure drop delta p in mbar. A characteristic 28 represents the pressure gradient due to the gas lines 10 in the breathing circuit 37 This is a linear dependence between the volume flow and the pressure drop in mbar due to the laminar flow within the gas line 10 , The characteristic 29 shows the pressure drop delta p in mbar as a function of the volume flow in l / min for the throttle body 13 , wherein here essentially a quadratic dependence or a dependence in the second power between the flow and the pressure change exists due to the turbulent flow in the region of the throttle body 13 , The characteristic 30 represents the sum of the characteristic 28 and the characteristic 29 ie, it is the characteristic curve of the entire breathing air circuit 37 with the gas line 10 and the throttle body 13 , The total resistance of the breathing circuit 37 ie the characteristic curve 30 , is 6 mbar at a flow rate of 60 l / min.

During an expiratory phase, the first expiratory pressure sensor is used 32 and the second inspiratory pressure sensor 33 the pressure measured and determined therefrom a mean pressure as patient pressure by means of a control unit, not shown. From the control unit during the expiration phase, the gas conveyor 2 operated with such a flow that the necessary residual pressure or PEEP pressure to the patient 7 is available. For example, the residual pressure is 5 mbar greater than the atmospheric pressure. The atmospheric pressure is detected by means of a further pressure sensor, not shown, and passed corresponding measurement signals to the control unit, not shown. Due to the high pneumatic resistance of the breathing air circuit 37 with the throttle body 13 Already a small change in the flow rate of the respiratory gas is sufficient to obtain a pressure change of the residual pressure. Furthermore, to achieve the residual pressure in an advantageous manner the Gas conveyor 2 be operated only with a low flow, so that thereby the necessary energy to operate the gas conveyor 2 while the inspiratory phase is low.

During the inspiration phase, the gas delivery device 2 operated at a higher flow rate than during the expiratory phase. In the inspiratory phase, the patient breathes 7 that of the gas conveyor 2 promoted inspiration gas. Because of the high pneumatic resistance of the throttle body 13 is only a small part of the gas from the conveyor 2 funded breathing gas not from the patient 7 inhaled, but flows through the expiratory gas line 8th and the throttle body 13 , As a result, even during the inspiration phase advantageously only a small drive energy for the gas conveyor 2 required. The first inspiratory check valve 4 prevents that from the patient 7 exhaled expiratory gas in the gas line 10 towards the gas conveyor 2 flows and the second expiratory check valve 9 Prevents breathing air through the expiratory gas line 8th to the patient 7 can be directed.

In 3 is a second embodiment of the ventilator 1 shown. In the following, only the differences from the first embodiment of the ventilator 1 according to 1 explained. Instead of a throttle body 13 with non-variable flow cross-sectional area is in the second embodiment, a throttle body 23 used with variable flow cross-sectional area. The throttle body 23 is with an elastic membrane 27 Mistake. A volume 16 on the elastic membrane 27 and outside the flow cross-sectional area of the breathing gas is by means of a connecting tube inspiratory pressure 15 fluid-conducting in connection with the gas line 10 between the gas conveyor 2 and the first inspiratory check valve 4 , The flow cross-sectional area of the throttle body 23 depends on the pressure in the gas line 10 from. The higher the pressure in the gas line 10 is, the smaller is the flow cross-sectional area of the throttle body 23 and vice versa. During an inspiratory phase, the gas delivery device becomes 2 operated at a high flow rate, so that at the gas line 10 a high pressure is present and thus on the throttle body 23 a small flow cross-sectional area and thus the pressure change or the pressure drop 12 on the throttle body 23 is very high. During an inspiratory phase, this is the result of the gas delivery device 2 funded inspiratory gas in whole or in part by the patient 7 inhaled, because the throttle body 23 has only a very small or no flow cross-sectional area for the passage of respiratory gas. The electrical energy for operating the gas delivery device 2 during the inspiration phase is very low. During an expiratory phase, the gas delivery device 2 operated with only a small flow rate. This occurs at the gas line 10 a low pressure, so that the flow cross-sectional area of the throttle body 23 is great. That of the patient 7 Expiratory gas exhaled during the expiratory phase can thus be expelled through the expiratory gas line 8th and the throttle body 23 be passed through. The necessary residual pressure during and after the expiration phase is controlled and / or regulated analogously to the first embodiment by means of a control and / or regulation of the delivery flow of the gas delivery device. The pressure drop 12 during the expiratory phase is at the throttle body 23 while sufficiently high, that even small changes in the flow rate of the gas conveyor 2 associated with a correspondingly large change in the residual pressure. A volume 16 (respectively. 18 in the following figures) in the throttle body 23 has the form.

In 4 is a third embodiment of the ventilator 1 shown. In the following, only the differences from the second embodiment will be according to FIG 3 shown. Instead of the connection tube inspiratory pressure 15 becomes a connecting tube expiratory pressure 17 for the throttle body 23 used, wherein the connecting tube expiratory pressure 17 in the gas line 10 between the throttle body 23 and the second expiratory check valve 9 connected. The throttle body 23 is thus of the form on the throttle body 23 controlled and / or regulated in an analogous manner to the second embodiment. The form depends on the volume flow at the throttle body 23 from.

In 5 is a fourth embodiment of the ventilator 1 shown. Hereinafter, only the differences from the third embodiment will be according to FIG 4 shown. Instead of the connecting tube expiratory pressure 17 is the elastic membrane 27 with a connection channel 19 or a connection opening provided.

In 6 in a second diagram, the abscissa represents the volume flow in l / min and the ordinate the pressure drop delta p in mbar. The characteristic 28 shows in an analogous manner to the first diagram according to 2 the pressure drop delta p as a function of the volume flow for the breathing circuit system 37 without the throttle body 13 . 23 , Due to the laminar flow in the gas lines 10 occurs here a linear or directly proportional dependence between the flow and the pressure drop. In the second, third and fourth embodiment of the ventilator 1 is the flow cross-sectional area of the throttle body 23 variable, being at a higher pressure in the gas line 10 the flow cross-sectional area of the throttle body 23 is reduced or vice versa. The pressure drop delta p at the throttle body 23 with variable flow cross-sectional area depends thus cubic or in the cube of the volume flow, through the throttle body 23 is directed. The characteristic 31 shows the cubic dependence of the pressure drop delta p in mbar on the volume flow in l / min. The characteristic 30 shows the sum of the characteristic 28 and the characteristic 31 ie it is the total pressure drop of the ventilator with the gas lines 10 and the throttle body 23 shown.

7 shows a fifth embodiment of the ventilator 1 , In the following, only the differences from the first embodiment will be described 1 described. In the gas line 10 between the throttle body 13 and the second expiratory check valve 9 is a valve 34 with housing installed. The valve 34 has an electromagnetic reciprocating piston 20 , a coupling rod 21 and a valve membrane 22 on. The valve membrane 22 can be moved, so that the valve 34 either the flow path between the throttle body 13 and the second expiratory check valve 9 opens or closes. During the expiratory phase is the valve 34 open, allowing the functioning of the ventilator 1 according to the fifth embodiment of the first embodiment. During the inspiration phase is the valve 34 closed so that through the expiratory gas line 8th no breathing air can flow. This will clear the entire of the gas conveyor 2 transported breath from the patient 7 inhaled, so that advantageously the gas conveyor 2 only consumes the energy needed to convey the inspiration gas.

In 8th is a sixth embodiment of the ventilator 1 shown. Hereinafter, only the differences from the fifth embodiment will be according to FIG 7 shown. The electromagnetic piston 20 and the coupling rod 21 for moving the valve membrane 22 in the fifth embodiment according to 7 are in the sixth embodiment by a servo valve 25 , a connection tube inspiratory pressure 24 and a connection tube inspiratory pressure 26 replaced. During the inspiration phase is the valve 34 closed and during the expiratory phase is the valve 34 open. During the inspiration phase, the gas delivery device 2 operated with a large flow rate, so that at the gas line 10 between the gas conveying device 2 and the first inspiratory check valve 4 a high pressure occurs. During the inspiratory phase, moreover, the solenoid operated servo valve 25 a fluid conducting connection between the connecting tube inspiratory pressure 24 and the connection tube inspiratory pressure 26 released, so that the high pressure in the gas line 10 between the gas conveyor 2 and the first inspiratory check valve 4 on the valve membrane 22 of the valve 34 can act, leaving the valve 34 closed is. During an expiratory phase, the gas delivery device 2 operated at a low flow rate, so that at the gas line 10 between the gas conveyor 2 and the first inspiratory check valve 4 a slight pressure occurs. During the expiration phase is the servo valve 25 closed, ie there is no fluid-conducting connection between the connection tube inspiratory pressure 24 and the connection tube inspiratory pressure 26 or the fluid-conducting connection is only briefly released, so that the valve 34 during the expiration phase and the expiratory gas through the expiratory line 8th and the throttle body 13 can flow.

In 9 is a seventh embodiment of the ventilator 1 shown. In the following, only the differences from the sixth embodiment will be described 8th described. The connection tube inspiratory pressure 26 gets directly to the valve 34 without a servo valve 25 and a connection tube inspiratory pressure 24 connected. During an inspiratory phase, the gas delivery device becomes 2 operated at a high flow rate, so that at the gas line 10 between the gas conveyor 2 and the first inspiratory check valve 4 a high pressure occurs. This is done by the movable valve diaphragm 22 and the high pressure in the gas line 10 the valve 34 closed during the inspiration phase. During the expiration phase, the gas delivery device 2 operated at a low flow rate, so that at the gas line 10 between the gas conveyor 2 and the first inspiratory check valve 4 a slight pressure occurs. Due to the low pressure in the gas line 10 is the valve 34 during the expiratory phase, allowing the expiratory gas through the expiratory gas line 8th and the throttle body 13 can flow.

Overall, with the ventilator according to the invention 1 significant benefits. Instead of a complex and expensive PEEP valve is a throttle body 13 . 23 used and by means of a control and / or regulation of the flow rate of the gas conveyor 2 the residual pressure controlled and / or regulated. An expensive and expensive PEEP valve is therefore not necessary, so that in a particularly advantageous manner the ventilator according to the invention 1 can be used well in the field of emergency and transport medicine and is inexpensive to manufacture.

LIST OF REFERENCE NUMBERS

1

ventilator

2

Gas conveyor

3

Manual ventilation bag

4

First check valve, inspiratory

5

Inspiration gas line

6

Patientenanschlusstück

7

patient

8th

Exspirationsgasleitung

9

Second check valve, expiratory

10

gas pipe

11

CO ₂ absorber

12

pressure drop

13

Throttle body with housing

14

cover

15

Connecting hose-inspiratory pressure

16

Volume of membrane ( 3 )

17

Connecting hose-expiratory pressure

18

Volume of membrane

19

Connecting channel for pressure equalization

20

Electromagnetic piston

21

coupling rod

22

valve membrane

23

Throttling element with variable flow cross-sectional area

24

Connection tube inspiratory pressure after servo valve

25

servo valve

26

Connection tube inspiratory pressure in front of servo valve

27

Elastic membrane of the throttle body

28

Characteristic pressure drop, laminar

29

Characteristic pressure drop throttle body, square

30

Total pressure drop

31

Characteristic Pressure drop Throttling element with variable flow area, cubic

32

First pressure sensor, expiratory

33

Second pressure sensor, inspiratory

34

Valve with housing

35

Y-piece

36

Breathing air line system

37

Breathing air circuit system

Claims (9)

Ventilator ( 9 ) for the artificial respiration of a patient ( 7 ), comprising - a gas conveying device ( 2 ), - at least one gas line ( 10 ) for forming a breathing air duct system ( 36 ), in particular a breathing circuit ( 37 ), - one in the gas line ( 10 ) arranged first check valve ( 4 ) for the formation of an inspiratory gas line ( 5 ) as part of the gas line ( 10 ), - one in the gas line ( 10 ) arranged second check valve ( 9 ) for the formation of an expiratory gas line ( 8th ) as part of the gas line ( 10 ), - one to the inspiratory and expired gas lines ( 5 . 8th ) connected patient connector ( 6 ), Means for obtaining a residual pressure in the patient fitting ( 6 ) and the expiratory gas line ( 8th ) during an expiration phase, characterized in that the atmospheric pressure is detected by a pressure sensor and a control and / or regulation of the delivery flow of the gas delivery device ( 2 ) is arranged to control and / or regulate the residual pressure during the expiration phase to a value which is greater than the atmospheric pressure, the residual pressure being determined exclusively by means of a control and / or regulation of the delivery flow of the gas delivery device ( 2 ) is controlled and / or regulated during the expiration phase and wherein an increase of the delivery flow of the gas delivery device ( 2 ) leads to an increase of the residual pressure and a reduction of the flow rate of the gas conveyor ( 2 ) leads to a reduction of the residual pressure. Breathing apparatus according to claim 1, characterized in that in the at least one gas line ( 10 ) in the flow direction after the second check valve ( 9 ), a throttle body ( 13 . 23 ) is installed to increase the pneumatic resistance of the breathing air system ( 36 ). Breathing apparatus according to claim 1, characterized in that in the expiratory gas line ( 8th ) in the flow direction after the second check valve ( 9 ), a throttle body ( 13 . 23 ) is installed to increase the pneumatic resistance of the breathing air system ( 36 ). Breathing apparatus according to claim 2 or 3, characterized in that a flow cross-sectional area of the throttle body ( 13 . 23 ) less than 50% of the flow cross-sectional area of the at least one gas line ( 10 ) is. Breathing apparatus according to one or more of the preceding claims, characterized in that by means of a first pressure sensor ( 32 ) the pressure in the expiratory gas line ( 8th ) is detectable and depending on the detected pressure during the expiratory phase of the flow of the Gas conveying device ( 2 ) is controllable and / or controllable. Breathing apparatus according to one or more of the preceding claims, characterized in that by means of a second pressure sensor ( 33 ) the pressure in the inspiratory gas line ( 5 ) and, depending on the detected pressure during the expiration phase, the flow rate of the gas delivery device ( 2 ) is controllable and / or controllable. Breathing apparatus according to one or more of the preceding claims 2 to 6, characterized in that the flow cross-sectional area of the throttle body ( 13 . 23 ) is changeable to the effect that at a pressure increasing in the at least one gas line ( 10 ) the flow cross-sectional area of the throttle body ( 13 . 23 ) becomes smaller and vice versa. Breathing apparatus according to one or more of the preceding claims 2 to 7, characterized in that the flow cross-sectional area of the throttle body ( 13 . 23 ) pneumatically by means of the respiratory gas in the at least one gas line ( 10 ) is changeable to the effect that at a pressure increasing in the at least one gas line ( 10 ) the flow cross-sectional area of the throttle body ( 13 . 23 ) becomes smaller and vice versa. Ventilator according to one or more of the preceding claims 2 to 8, characterized in that in the expiratory gas line ( 8th ) in the flow direction in front of the throttle body ( 13 . 23 ), a valve ( 34 ) and during the inspiration phase the valve ( 34 ) is closed and during the expiratory phase the valve ( 34 ) is open.

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