DE102006032663B3 - Recovery system for recovering gaseous substances operates with machine respiration or spontaneous respiration to separate gaseous substances - Google Patents

Abstract

A recovery unit (6) separates gaseous substances and connects in an exhaling side (5) in front of or after a respiratory device (1). The recovery unit has a cooled cavity system (7) with a constant capacity. There is a passive through- flow through the cooled cavity system during exhalation.

Description

The The invention relates to an arrangement for the recovery of gaseous substances with mechanical ventilation or with spontaneous breathing.

to Application of gaseous and liquid Materials used in mechanical ventilation are so far evaporators, nebulizers and evaporators used.

Evaporator, as in anesthesia ventilators for inhalation anesthesia used to serve the pure oxygen or a Gas mixture containing the for the respiratory oxygen required to add an anesthetic. In A chamber of the evaporator forms above the liquid form filled Anesthetic one Gas phase whose maximum partial pressure corresponds to the saturation of the gas mixture. The concentration of anesthetic in the gas mixture that reaches the lungs of the patient is through controlled an adjustable division of the breathing gas flow, so that the applied partial pressure clearly below that of the saturated Gas phase is.

nebulizer, as in intensive care medicine for the administration of liquid drugs are used to produce an aerosol in the breathing gas mixture, which is then inhaled.

Verdunster, as they are used in intensive care to humidify the respiratory gases The mechanical ventilation used to warm up the inspiratory gas mixture and its saturation with water vapor. To For this purpose, a chamber filled with water is heated and the Breathing gas mixture at the inspiration over the surface of the Passed water.

When applying gaseous substances, their consumption depends on the type of application system and its setting:
Half-open systems are almost exclusively used in intensive care ventilators and animal respirators. In such a system, the gas mixture exhaled by the patient during expiration is drained via a tube and the expiratory valve and not reused.

semi-closed and closed systems, on the other hand, are used in anesthesia ventilators and provide a circular system with partial to complete reuse of the exhaled gas mixture. They are based on the principle that the respiratory flow during the Expiration together with the fresh gas flow in a rubber bag or rubber bellows is passed. This flexible cavity can be constructive be arranged so that he is directly at the subsequent inspiration is emptied or has the function of a buffer memory. The at the reuse of the gas mixture required elimination of the Carbon dioxide is caused by the chemical reaction between carbon dioxide and lime realized in a filled with "soda lime" Chamber of the circuit system runs while flowing through the gas mixture. to Prevention of condensation of body-warm respiratory gas components through contact with cooler Components of the ventilation system need to be heated, otherwise, expensive technical Arrangements are made, e.g. Condensation from the breathing circuit part which otherwise interferes with the function of the breathing circuit part.

Opposite half-open Systems have semi-closed and closed systems the advantage that the consumption of anesthetics due to the return or Reuse of the exhaled gas mixture significantly reduced can be. The disadvantage turns out to be that a constant flow of fresh gas direct or buffered - in the respiration technique is called this form decoupled - fed will and for the ventilation a second independent Drive is required, as well as the amount of remaining in the circuit system potentially toxic substances is higher as well as larger amounts to accumulate condensation.

From the publication DE 198 23 606 A1 For example, the use of perfluorohexane F ₃ C (CF ₂ ) ₄ CF ₃ , a linear molecule saturated with fluorine atoms, as a component of the breathing gas mixture for the treatment of pulmonary failure is known.

About perfluorocarbons is known to belong to a group of substances containing hydrocarbons Is related. Unlike these are in the molecules that Chain, ring or more complex structures may have, the Hydrogen atoms replaced by fluorine atoms. The physical properties vary with the structure of the molecules, but especially with the Number of carbon atoms.

About the maximum vapor pressure of a substance on its liquid phase at a temperature below its boiling point is known that it is temperature dependent and in a good approximation with the formula P = 10 ^{A- (B / (T + C))} [P = vapor pressure (bar ), T = temperature (K)] can be calculated. The substance-specific parameters A, B and C are available in the literature.

The application of perfluorohexane with the aid of evaporators on an anesthesia ventilator (publication DE 198 23 606 A1 ) has the disadvantage that the maximum partial pressure of perfluorhe xan is determined by the room temperature, since the evaporator and the circuit system are not heated to body temperature. For the use of perfluorohexane in the ventilation of intensive care patients, the use of intensive care ventilators would also be advantageous.

From the publication DE 101 07 917 C2 a method for low-consumption application of gaseous substances is known that reduces the elimination of the applied substance by an existing between patient and ventilator application system by the gas mixture is passed during exhalation through a cavity in which the applied substance, in part and in the subsequent Inhalation returns to the patient's lungs due to the reverse flow direction.

A problem of this solution is that in addition to the intended enrichment of the reusable gas to be reused in the Rückatemanteil the simultaneous accumulation of potentially harmful trace gases is either produced by the patient organism (eg methane) or resulting from the chemical reaction of those in the resulting gas mixture with each other or with the components of the application system arise (eg reaction of sevoflurane with soda lime leads to the compound A formation), especially at longer intervals of use as are common in intensive care. Another problem is the usability of the in the document ( DE 101 07 917 C2 ) described application system at smaller tidal volumes, as they occur during respiration or during spontaneous breathing of infants, toddlers and small animals. In this case, the tidal volume is considerably lower than the void volume, which considerably prolongs the time constant of the system and thus makes dynamic, timely control of the gas concentrations more difficult. Furthermore, when using the in the document ( DE 101 07 917 C2 ) described application system, the problem of simple control of the individual components of the gas mixture. This can only be realized by a near-patient gas measurement and a complex tracking of the individual gas components based thereon. If the tracking is close to the patient (between the cavity and the patient), the effectiveness of the application system is significantly impaired in terms of its low consumption, this is especially true for the control of gases with a high proportion of respiratory gas (eg oxygen, nitrogen). If the tracking is remote from the patient (between the respirator and the cavity) considerable demands are placed on the (electronic) control of the tracking of all gas components.

The The object of the invention specified in claim 1 is to the application gaseous To improve substances so that the substance to be applied minimizes the consumption, the concentration preferably simply controllable with low time constant, it is none at all Accumulation of potential trace gases comes, condensates from the respiratory gas be eliminated and the use of intensive care and children as well (Small) animal respirators allows becomes. Furthermore should be a simple application system available for backup In the life of the patient, there were no additional active components requires that the respiratory mechanism of the lungs as little as possible and if necessary exclusively controlled influences.

The The object is achieved by an arrangement with the mentioned in claim 1 Characteristics solved.

further developments and embodiments of the arrangement are the subject of dependent claims.

According to the invention a recovery the applied substance by its conversion into the liquid state of matter with the help of an inserted into the exhale limb of the ventilator Recovery unit the recovered liquid for the re-evaporation, evaporation, nebulization, etc. are provided again can.

The specified in claim 2 embodiment of the invention has the Advantage that substances that exist in liquid form at room temperature, recovered can be. These are in the Einatemschenkel over the variable Gaszumischung on the ventilator introduced, because over the liquid Phase forms a gas phase as part of the gas mixture, the should be applied without it during the next or subsequent exhalation phases is lost, but back is won. This is particularly advantageous in the case of the claim 3 substances mentioned.

A advantageous embodiment of the invention is characterized by the in the claim 4 specified property of the cavity system achieved that this on the within the breathing cycle variable pressure level of the exhale limb of the ventilator works as the driving force for the gas flow through the apparatus not through additional active Components must be applied, but by the ever-present elastic restoring forces of the Thorax of the patient and / or the lung exists.

The specified embodiment of the invention has the advantage that the specified in claim 5 ratio of V _H > V _T between the void volume of the capacitor V _H and the Tidal volume V _T especially in infants and small animals occurs because the vapor pressure of a substance at its temperature below its boiling point is proportional to its temperature and a condensation resulting from a drop in vapor pressure is more effective the stronger the temperature drop of the gas produced which can be maximized by prolonging the contact time of the gas with the condenser in view of the effectiveness of the recovery of the applied substance.

The specified in claim 6 embodiment of the invention has the Advantage that the cavity system of the capacitor unit at the same time Advancement of the exhaled gas and the separation and derivation of the Condensates in the same compartment ensured, as the recovery of the applied substance can be maximized under this condition.

The specified in claim 7 embodiment of the invention has the Advantage that the total cross-sectional area of the recovery unit the same within the breathing cycle variable gas flow of the exhale limb of the breathing circuit leads, since influencing the respiratory mechanics of the patient in this way can be reduced to a minimum.

The specified in claim 8 embodiment of the invention has the Advantage that the gas flow within the cavity system of the condenser unit while the inspiratory phase, which is variable in time within a respiratory cycle Zero is because the vapor pressure of a substance is above its liquid phase at a temperature below its boiling point proportional to its temperature behaves and a condensation resulting from a vapor pressure drop the more effective the stronger the generated temperature drop of the gas is due to a prolonged contact time of the gas with the condenser in view of the effectiveness of the recovery the applied substance can be maximized.

The specified in claim 9 embodiment of the invention has the Advantage that the 2 or 3-dimensional arrangement of the partial cavities of the Cavity system provides a minimal gas flow resistance, as the Influencing the respiratory mechanics of the patient in this way a minimum can be reduced.

According to claim 10 leaves the cross-sectional enlargement is continuous or abruptly.

The has specified in claim 11 embodiment of the invention the advantage that the 2 or 3-dimensional arrangement of the cavity system ensures a homogeneous distribution of the gas flows herein, because the recovery the applied substance under this condition maximizes, as well as the influence of the respiratory mechanics of the patient under this condition can be reduced to a minimum.

A further advantageous embodiment of the invention is in the claim 12 indicated. It allows through the use of materials with high thermal conductivity for the condenser unit a good temperature transition from the coolant the respiratory gas, because the recovery the administered substance can be maximized under this condition can.

The has specified in claim 13 embodiment of the invention the advantage that the 2 or 3-dimensional arrangement of the subspaces or the Drainage devices of the cavity system largely a hydrostatic gradient has, since in this way a rapid drainage of the condensates all areas of the cavity system is reached, since the condensates due to their vapor pressure properties on the one hand with the gas phase to be in equilibrium and thus to return to it can and on the other hand built by the occurrence of condensates flow resistance within of the cavity system can be minimized and thus simultaneously the recovery of the applied substance can be maximized under this condition, as well as influencing the respiratory mechanics of the patient under this Condition can be reduced to a minimum.

The has specified in claim 14 embodiment of the invention the advantage that the 2 or 3-dimensional arrangement of the cavity system via partial cavities or Has drainage devices, their individual gas passage surfaces in relation to to the slope the respective partial cavity or the drainage device and under consideration the respective cross-sectional profiles are sufficiently large, at the same time an effective drainage of the condensate at minimum Gas flow obstruction to achieve, since the influence of the respiratory gas flow due the presence of the condensate in the same cavity and the Resulting influencing the respiratory mechanics of the patient under this condition can be reduced to a minimum.

The specified in claim 15 embodiment of the invention has the advantage that the 2 or 3-dimensional arrangement of the partial cavities or drainage devices of the cavity system at its lowest point has a drain, since the condensate can be collected here for later reuse and the recovery of applied substance can be maximized under this condition.

The has specified in claim 16 embodiment of the invention the advantage that the discharge of the cavity system from its lowest point from cooled in a collection container takes place in which the condensate can be collected, as the recovery the administered substance can be maximized under this condition can.

The has specified in claim 17 embodiment of the invention the advantage of having a collection container for the Condensate is at the pressure level of the exhaled gas, since on this Way the impact on the respiratory mechanics of the patient is minimized becomes.

The has specified in claim 18 embodiment of the invention the advantage of having a collection container for the Condensate has a pressure lock, from which the recovered substance in another container independent of the airway pressure is performed because in this way the influence of the respiratory mechanics of the patient during the Condensate removal can be reduced to a minimum.

The has specified in claim 19 embodiment of the invention the advantage that they have a separator for the condensates of different densities has, because the sorted recovery of the applied substance can be maximized under this condition.

The has specified in claim 20 embodiment of the invention the advantage of being an outside the cooling bypassing the condenser unit exists which eliminates the If necessary, the applied substance is reduced to zero.

The has specified in claim 21 embodiment of the invention the advantage of being an outside the cooling bypassing the condenser unit serves as a "fail safe" device since this way influencing the respiratory mechanics of the patient at the moment one Gas flow resistance increase is reduced to a minimum in the cavity system.

The has specified in claim 22 embodiment of the invention the advantage that the gas flow resistance of serving as a "fail safe" device Bypassing of the condenser unit which is located outside the cooling under normal operating conditions is higher than the resistance of the Condenser unit itself but lower than the patient safety debilitating Resistance, in this way influencing the respiratory mechanics of the patient at the moment of a gas flow resistance increase in the condenser unit and the consumption of the applied substance a minimum can be reduced.

The has specified in claim 23 embodiment of the invention the advantage that any form of cooling comes into question, the one sufficient drop in the breathing gas temperature in the recovery unit can generate, as the vapor pressure of a substance on the liquid Phase at a temperature below its boiling point proportional behaves to its temperature and a condensation resulting from a vapor pressure drop the more effective the stronger the generated temperature drop and consequently the recovery of the applied Substance can be maximized.

The has specified in claim 24 embodiment of the invention the advantage that the recovery unit be designed as a collapsible reusable component of ventilators can.

The specified in claim 25 embodiment has the advantage that the recovery unit Also can be designed as a disposable item to medical-hygienic claims under these conditions.

The has specified in claim 26 embodiment of the invention the advantage of having parts of the recovery unit designed as disposable components can be which together with reusable components to a complete Recovery unit can be assembled there medical-hygienic as well as economic and ecological claims under these conditions can best be met.

The has specified in claim 27 embodiment of the invention the advantage that the recovery unit with regard to ecological aspects as a procedural component within a building vehicle or plant exhaust system can be executed.

The Overall achieved with the invention advantages are in particular in that a low-consumption application of gaseous substances with respirators in the Adult and Intensive care medicine, veterinary medicine and animal experiments Applications possible is. Across from The application forms known hitherto result from the reduction of consumption economic and ecological Advantages, the significance of which mainly depends on the applied substance depends.

Embodiments of the invention are in illustrated the drawings. Show it:

1 an arrangement of the recovery unit to the ventilator

2 a schematic representation of a recovery unit with fan-shaped cavity system

3 a schematic representation of a recovery unit with drainage devices in side view

4 a schematic representation of a recovery unit with drainage devices in cross section

In the 1 an arrangement of the recovery unit to the ventilator is shown schematically.

The ventilator 1 is connected to the anesthetic vaporizer through an incoming and outgoing tube.

About two hoses is the ventilator 1 with the lungs 4 connected to the patient. The right hose in the 1 forms the breathing gas supply 3 , The left tube forms the exhale limb 5 with the recovery unit 6 in front of the ventilator 1 which is breathed by the breathing gas mixture during exhalation.

Variation arises with the use of semi-closed or closed anesthesia systems via the connection 1a between inhalation and exhalation legs. With these devices, installation of the recovery unit is in position 6a meaningful.

An embodiment for a recovery unit is in the 2 shown. In a coolant environment 8th is a cavity system 7 stored. To form the cavity system is a checkerboard branching of the gas supply line 18 seen in individual partial cavities. At the lowest point of the branching points the cavity system 7 a process 20 on. To this process, the partial cavities lead to a strand together. Likewise, the merging of the partial cavities takes place to the gas discharge 19 also to a strand.

A merge on a strand for gas discharge 19 and to the process 20 is not essential, but only represents an advantageous embodiment. Likewise, the supply of the partial cavities can be carried out on a manifold, which then into a gas discharge 19 or in a sequence 20 empties.

The condensate formed during the cooling of the exhaled gas flows within the in 1 illustrated hollow space system 7 due to the construction of gravity following the procedure 20 at the lowest point of the cavity system 7 ,

There are two pressure valves in the recovery unit 9.1 and 9.2 provided with variable resistance. The pressure valve 9.1 regulates the gas flow in the cavity system 7 , The pressure valve 9.2 regulates the gas flow through an uncooled bypass circuit 10 ,

At the expiration 20 is a collection container 11 at the lowest point of the cavity system 7 intended. In the collection container 11 the accumulating condensate is collected. The collection container 11 gets in with the exhale thigh 5 prevailing variable pressure applied. Via a pressure lock 12 The condensate can affect the pressure inside the exhale limb without affecting the pressure 5 a collection container 13 and a separator 14 be supplied.

The coolant environment 8th has a thermal insulation 15 on, in which a closable opening 16 can be done for filling with a coolant and for emptying.

In addition to the already described variation of the partial cavities, the cavity system can alternatively be realized by drainage devices. Such an arrangement is in the 3 and 4 shown.

From the gas supply 18 run with a certain tendency to expiration 20 towards several drainage facilities 17 , The drainage devices 17 each form a pair in a comb-like arrangement, wherein the two combs are arranged in a pair overlapping.

The condensation takes place due to the cooling of the drainage devices 17 , The condensate passes through the inclination of the drainage devices 17 the end 20 , For cooling, there is the comb-like arrangement of the drainage devices 17 in a coolant environment 8th ,

In an arrangement such as in 3 and 4 shown, the coolant environment can be 8th advantageously also produce by Peltier elements instead of a gaseous or liquid coolant.

1

ventilator

1a

additional connection in anesthesia ventilators (half closed, closed)

2

Verdunster or injector

3

Breathing gas supply

4

Patient / lung

5

Ausatemschenkel

6

Recovery unit

6a

alternative Installation in anesthesia ventilators (half closed, closed)

7

Cavity system / condenser

8th

Cooling / coolant environment

9

variable Resistance / pressure relief valve

10

Collateral circulation

11

Collecting container (pressure-dependent)

12

pressure lock

13

Collecting container (pressure independent)

14

separators

15

Coolant tank with thermal insulation

16

Opening of coolant tank can be closed

17

off device

18

gas supply

19

gas discharge

20

procedure

Claims (27)

Arrangement for the recovery of gaseous substances in mechanical respiration or in spontaneous breathing, characterized in that for the separation of the gaseous substance, a recovery unit ( 6 ) is provided, which in the exhale ( 5 ) before or after a ventilator ( 1 ), the recovery unit ( 6 ) a cooled cavity system ( 7 ) with constant volume, the cavity system ( 7 ) passively exhaled, and wherein the gaseous substance condenses in an amount dependent on the vapor pressure reduction caused by temperature reduction of the exhalation gas, and from the void system ( 7 ) is derivable. Arrangement according to claim 1, characterized in that the temperature reduction in the cavity system ( 7 ) of the recovery unit ( 6 ) is so dimensioned that a recovery of a gas mixture containing at least one substance with a boiling point above 21 ° C is carried out. Arrangement according to claim 1 or 2, characterized in that the temperature reduction in the cavity system ( 7 ) of the recovery unit ( 6 ) for the recovery of perfluoropentane, perfluorohexane, perfluoroheptane, perfluorooctane, perfluoromonanes, perfluorodecane, isoflurane, desflurane or servoflurane individually or in combination. Arrangement according to one of claims 1 to 3, characterized in that the cavity system ( 7 ) is designed to receive the variable pressure level in the exhale limb. Arrangement according to one of claims 1 to 4, characterized in that for use in infants and small animals, the void volume of the cavity system ( 7 ) V _h to the tidal volume V _t in the ratio V _h > V _t . Arrangement according to one of claims 1 to 5, characterized in that the cavity system ( 7 ) of the recovery unit ( 6 ) for the passage of the exhaled gas, a gas supply line ( 18 ) and a gas discharge ( 19 ) and for discharging the condensate has a sequence ( 20 ) is provided. Arrangement according to one of claims 1 to 6, characterized in that the total cross-sectional area of the cavity system ( 7 ) is designed to accommodate the variable within the breathing cycle gas flow of the exhale limb of the breathing circuit. Arrangement according to one of claims 1 to 7, characterized in that the gas flow within the cavity system ( 7 ) of the recovery unit ( 6 ) while the inspiratory phase variable in time within a respiratory cycle is zero. Arrangement according to one of claims 1 to 8, characterized in that the 2 or 3-dimensional arrangement of the cavity system a minimum Gas flow resistance by a cross-sectional enlargement in the flow direction having. Arrangement according to claim 9, characterized that the cross-sectional enlargement is continuous or abruptly is. Arrangement according to one of claims 1 to 10, characterized in that for the homogeneous distribution of the gas flow, the 2 or 3-dimensional arrangement of the cavity system ( 7 ) from the gas supply line ( 18 ) has a uniform branching in partial cavities. Arrangement according to one of claims 1 to 11, characterized in that for the cavity system ( 7 ) Materials are provided with a suitable thermal conductivity. Arrangement according to one of claims 1 to 12, characterized in that the 2 or 3-dimensional arrangement of the partial cavities or the drainage device of the cavity system ( 7 ) has largely a hydrostatic gradient. Arrangement according to one of claims 1 to 13, characterized in that the 2 or 3 di Metric arrangement of the cavity system ( 7 ) via partial cavities or drainage devices ( 17 ), whose individual gas passage surfaces in relation to the slope of the respective partial cavity or the drainage device and taking into account the respective cross-sectional profiles is dimensioned so that at the same time an effective drainage of the condensate is generated with minimal gas flow obstruction. Arrangement according to one of claims 1 to 14, characterized in that the 2 or 3-dimensional arrangement of the partial cavities or the drainage devices ( 17 ) of the cavity system ( 7 ) at its lowest point a process ( 20 ) exhibit. Arrangement according to one of claims 1 to 15, characterized in that the discharge of the cavity system from its lowest point with a collecting container ( 11 ) is connected and discharge and collecting container are cooled. Arrangement according to one of claims 1 to 16, characterized in that a collecting container ( 11 ) is acted upon for the condensate with the pressure level of the exhalation gas. Arrangement according to one of claims 1 to 17, characterized in that on the collecting container ( 11 ) for the condensate a controllable pressure lock ( 12 ) connected to another container independent of the airway pressure. Arrangement according to one of claims 1 to 18, characterized in that the pressure-independent collecting container ( 13 ) a separator ( 14 ) is connected for the condensates of different densities. Arrangement according to one of claims 1 to 19, characterized in that a bypass of the cavity system located outside the cooling ( 7 ), so that the elimination of the applied substance can be reduced to zero if necessary. Arrangement according to one of claims 1 to 20, characterized in that a bypass outside the cooling system of the cavity system ( 7 ) is designed as a safety device. Arrangement according to claim 21, characterized in that the gas flow resistance of serving as a safety device bypassing the cavity system ( 7 ) is located outside the cooling, and is higher than the resistance of the cavity system under normal operating conditions ( 7 ) itself, but lower than a patient safety compromising resistance. Arrangement according to one of claims 1 to 22, characterized in that for cooling the cavity system ( 7 ) means are provided for generating a sufficient drop in the respiratory gas temperature in the recovery unit ( 6 ) are suitable. Arrangement according to one of claims 1 to 23, characterized in that the recovery unit ( 6 ) is designed as a dismountable reusable component of ventilators. Arrangement according to one of claims 1 to 23, characterized in that the recovery unit ( 6 ) is designed as a disposable item. Arrangement according to one of claims 1 to 25, characterized in that parts of the recovery unit ( 6 ) are designed as disposable components which, together with reusable components, form a complete recovery unit ( 6 ) are composable. Arrangement according to one of claims 1 to 26, characterized in that the recovery unit ( 6 ) is executed as a component within a building, vehicle, or plant exhaust system.