Device and method for tempering and humidifying gas, especially respiratory air

Translation of description of equivalent WO 2004040202 A2

p000120,056 (Pe / be)

p0002Device and method for heating and humidification of gas, in particular of breathing air

p0003D escription

p0004The invention relates to a device for heating and humidification of gas, in particular of breathing air, said device comprising a fluid reservoir and a humidification chamber having an inlet and an outlet for the gas, and a movement device for the liquid through the gas to move. The invention also relates to a corresponding method.

p0005Such an apparatus and method to be used in particular for ventilating a patient. Within the scope of the invention described herein, the term "respiration" is understood any kind of respiratory therapy and "patient" includes both humans and animals are to be understood.

p0006Such ventilating a patient is usually performed by means of an apparatus having a breathing tube, a breathing gas flow generator and a humidifier for the respiratory gas. The gas flow generator, the breathing gas is supplied from a reservoir and it also has a port for the ventilation hose onto.

p0007Under a gas flow generator is essentially a functional unit to understand the pressure to a patient to be administered respiratory gas and / or volumetric flow moderately regulated, for example, valves or a blower. But this functional unit can also be part of a larger apparatus.

p0008When the breathing gas, it will usually be air / oxygen mixtures, but it can also have special other gas mixtures to be administered.

p0009The liquid that is present in the liquid reservoir and with the moistening takes place of the gas or air, it usually is water. In the present invention, other liquids or mixtures of liquids here are conceivable, as well as those to which medications have been added. Patients who are ventilated by equipment, a tube is usually inserted into the trachea via the respiration takes place. This tube is seated at the end of a respiratory tube, through which a gas flow generator to the patient breathing gas emits. It may end up on the tube even more breathing tubes.

p0010The delivery of respiratory gas through the gas flow generator is usually a function of different parameters that can be adjusted as required to the gas flow generator and then automatically maintained by this unit, or can be varied as required. Depending on the device or set parameters of the respiratory flow in the temporal course of the respiratory phase is very different. In previously known ventilation systems, this leads to considerable problems:

p0011The tube in the trachea, the natural function of the nose, mouth and throat is namely bypassed, the heated and humidified breathing gas at normal breathing. Also in respiratory care, such. As the continuous positive pressure breathing therapy with facial mask (CPAP) remains indeed flow through the nose and throat from breathing gas, by compared with natural spontaneous breathing of a patient but much higher and often continuous gas flow but occur particularly when use of dry cold gases often unwanted side effects. These include irritation and inflammation as well as drying out and Verborkungen the upper airways.

p0012To overcome this problem, when the ventilator is the related gas coming from a reservoir such as a gas cylinder or a compressed gas line, or else by a fan, a blower or the like from the environment is taken as a reservoir and which is usually relatively dry, artificially humidified and heated.

p0013, You try doing as much as possible to achieve the natural conditions, therefore, to temper the respiratory gas to a temperature corresponding to the body temperature and to moisturize it, so that it is largely saturated. The aim here is especially a rela- tive humidity of about 95-100%.

p0014This is particularly difficult in the above described volatile gas streams, such as occur during spontaneous breathing or mechanical ventilation.

p0015A similar problem is also found in other areas of medicine, in which a device according to the invention can be used, such. As in laparoscopy. This gas is (often carbon dioxide) for the purpose of distention of body cavities in the body, eg. As in the abdominal cavity introduced. Also, in this and similar applications can be achieved by heating and humidification preferably up to a substantial satura- account the related gas a previously frequent irritation of mucous membranes and their drying and cooling can be prevented.

p0016It should be noted that even in this application highly fluctuating gas flows are observed since the introduction or removal of instruments into or out of body orifices does a quick readjustment of the gas flow required to maintain the pressure in a body cavity constant.

p0017In principle, various techniques and methods are known to temper gas in the above applications to a default value and moisturize. Below are some methods and apparatus are described for this purpose:

p0018Pass-over-evaporator (z. B. DE 38 30 314)

p0019In this prior art apparatus a to temperierendes and to be humidified gas is passed over the surface of a heated water bath and heated and humidified thereby simultaneously. The liquid surface cools down as a result of evaporation of water and is slowly replaced by warmer, rising upwards water.

p0020Due to the limited by the application in a ventilator system size, the exchange surface between liquid and about hinwegströmendem gas is very small. The cooling described the surface and the resulting slow energy transport by warmer water on the surface results in such a humidifier to the fact that a leaking gas depending on the gas flow amount smaller or larger temperature differences for liquid having. Therefore, in a device of this type, the liquid temperature is also controlled only on an average gas flow amount and moves in conventional devices between about 40 ° C and 80 ° C. Wildly fluctuating gas streams as they are normal according to the above in ventilation have, thus in the instantaneous value of consideration either too high or too low a temperature and a too high or too low humidity. This could be readjusted only by only theoretically possible sudden changes in water temperature.

p0021Membrane evaporator (z. B. DE 43 03 645)

p0022In such a device gas is passed over the surface of a structure projecting out of tempered liquid body. The structural body draws in the required liquid z. B. by capillary action. Only the respective vaporized liquid is replaced. The disadvantage here is in particular that by the evaporative cooling and the only low energy supply by warmer water creates a similar problem to the pass-over evaporators discussed above, so that ultimately a variable gas flow neither constant nor moistened can be temperature constant. In passing it should be mentioned that the aforementioned structural body often only partially are durable and also their desirable for medical use autoclaving is usually restricted.

p0023Hollow fiber humidifier (z. B. DE 197 27 884)

p0024Partially permeable hollow fibers (z. B. PTFE) are bundles so arranged that too temperierendes and z to be humidified gas. B. flowing through the lumen of the hollow fibers on the outer sides of the liquid required for humidification is present. A disadvantage of these humidifiers is both the often only limited durability and the limited mechanical and thermal resistance of the hollow fibers. In addition, is given by the wall of the hollow fibers sufficient thermal conductivity so that the heat supply is not sufficient to compensate for evaporation. Thus, especially at higher gas flows a desired heating of the gas can not be guaranteed, which is accompanied simultaneously with a poor moistening of the gas. Again, in theory, be adjusted by a heating of the water, but also forcibly heating the fibers with widely fluctuating gas flow does not lead to a constant moistening, as the power output of the heating elements for technical reasons hardly in the rate of gas flow change is to be readjusted.

p0025High temperature evaporator (z. B. DE 43 12 793)

p0026In such devices C are small amounts of liquid evaporated and mixed with the flowing gas at temperatures of about 80 ° C to about 130 °. This both the energy required for heating the gas and the humidity requirements are met. The disadvantage of these devices is particularly of high technical complexity, which is also still associated with an increased technical risk, especially with regard to hazards due to pressure and heat. Furthermore, the devices have the disadvantage that the control of the required amount of evaporation only with a time lag can occur. Thus, with such a device with widely fluctuating gas stream to achieve no constant heating and humidification.

p0027Sparging Humidifier (z. B. DE 37 30 551)

p0028In devices of this kind by a temperature controlled liquid gas is bubbled (pass), whereby it is moistened and heated. The disadvantage of this method is especially the process-related high gas flow resistance, since it is always at least one differential pressure has to be overcome, which corresponds to the entry depth of the gas in the liquid. This is extremely disadvantageous above all learning in spontaneously breathing patients. Ultraschallvemebler (z. B. DE 197 26 1 10)

p0029In such devices, liquid is induced to vibrate in the ultrasonic range, which means that dissolve tiny droplets of the liquid and can be entrained in the gas stream. This is particularly disadvantageous that this is no way to present liquid is in molecular form but much larger units (aerosols). This allows various pathogens are transported undesirably. Furthermore, this method also the danger that is discharged too much or too little moisture, particularly in intermittent or fluctuating gas flows.

p0030Pressure Jet (z. B. DE 28 34 622)

p0031In devices of this type, a liquid is atomized, resulting in that also form small droplets and not z. B. molecular water vapor. The disadvantages of this pressure atomizer thus correspond to the previously discussed ultrasonic nebulizers.

p0032Artificial noses ( "heat and moisture exchanger"; HME, eg DE 94 17 169)., Filter mats, etc.

p0033For artificial noses, the gas is passed over a very large wetted surface, thereby substantially moisture saturation of the gas stream is achieved. The artificial nose, the heat and moisture is supplied via the exhaled air of a patient. If filter mats, z. B. from the air conditioning systems, carried out heat and moisture supply z. B. a water bath. This filter mats filtration of the gas is carried out simultaneously.

p0034A disadvantage of these known devices, in particular, that the evaporative cooling leads to a gas flow dependent cooling so that humidification and Temperierungsleistung can not be constant with variable gas flow. Furthermore, it is disadvantageous in these devices that retained in the filtration materials increase during the period of use of the flow resistance of the filter mats for the gas, which is particularly undesirable in the medical report. Even the HME in inputs and Ausatembereich of patients, the dead space is increased adversely by the principle conditional assembly. This can lead to a patient in one breath a great part of the air inhaled, which he has previously just exhaled.

p0035Booster Systems (z. B. DE 44 32 907)

p0036In these systems attempt to compensate for the insufficient efficiency of artificial noses (HME) by means of supply of fluid and heat. This requires a technically rather elaborate scheme. In addition, the system ensures that also with widely fluctuating gas flow temperature and humidity can not be kept constant, as well as a very good control, the resulting evaporative cooling can not compensate without delay. The above-described adverse dead space, as well as the adverse size and the adverse weight are in these systems by other ELEMENTS, explained here in detail E- further increased.

p0037Combination of the previously discussed method (DE 296 12 115).

p0038In this combined method the gas is first superheated and moistened, and then cooled in a subsequent second stage by means of constant tempered metal ribs o. Ä. To the target temperature. Excess moisture in the gas is hereby drop as the temperate condensate of metal ribs, and fed back to the humidifier. A disadvantage of this method is in particular that the gas is supplied first more energy in the form of humidity and temperature, as is required for the ventilation.

p0039Besides the fact that this is energetically unfavorable, there is also the risk that a malfunction in the cooling step a patient can then be permanently damaged.

p0040Space Air Humidifier with rotating disk stack (z. B. DE 37 35 219)

p0041In such systems, stacks of plates rotate such that the plates immersed in a part of their operating cycle in water and are wetted thereby. The gas flows by means of a ventilator past these stacks of plates and should therefore be cleaned and wetted particles. In these devices, the liquid is to be a non-volatile agent is added to reduce the surface tension in order to actually achieve a sufficient Plattenbenet- pollution. These and similar devices are especially designed for LIVING climate control and have no way to control the temperature of the gas on. In addition, the dimensioning and the rotational speed of the plates is adapted in any way to humidify a variable gas flow constant or even saturated with a liquid.

p0042It must be so collectively determined that no methods and systems for heating and humidification of gases are present in the prior art that would be suitable for use in highly fluctuating or intermittent gas flow. In the previously known devices, this results in considerable fluctuations of temperature and humidity of the gas delivered.

p0043Another disadvantage of known devices is that they, in some cases considerably worsen the precision of measurement and control processes that are desired for a ventilator tern or even prevent all: For example, there are methods and sensor systems for ventilation, which require immediate possible coupling of a gas flow generator device or a sensor on a patient to this the required breathing gas in a predetermined constant quantity and quality, and in particular with precise volume flow rates to administer men.

p0044The known today humidifier between a gas flow generator and

p0045Patients are placed, are disadvantageous as they have an additional compressible

p0046Volume of partly considerable size is introduced into the breathing circuit.

p0047Another disadvantage of the known humidifier is also the pressure gradient which exists in some conventional humidifiers between the input and output: Since the pressure of supplied to the patient breathing gas (respiratory gas level) is only slightly higher than the ambient pressure (usually not more than about 0.1 bar ) takes this pressure gradient to the fact that the gas flow generator itself does not accurately present the ruling on patient pressure. This has the risk of malfunctions and inaccuracies in the scheme as a consequence.

p0048Object of the present invention is therefore to provide devices as indicated above in such a way that the aforementioned disadvantages are eliminated and in particular gas is independent of gas flow fluctuations to temper constant at a preset value, and it is particularly largely saturate at this temperature with a liquid, that is, up to a relative humidity of about 95-100%.

p0049This object is achieved by providing a device for heating and humidification of gas to a liquid reservoir and a humidification chamber having an inlet and an outlet for the gas, as well as a moving device to move the fluid through the gas, a regulated comprises heating the liquid.

p0050The invention has over the prior art several advantages:

p0051On the one hand there is the possibility to have the moving device and the controlled heating of two elements can be reached via the regulation of the heating and humidification.

p0052Secondly, over these two elements, which can be controlled independently of one another, a quite intense heating and humidification can be achieved, so that the device can be made relatively compact.

p0053Furthermore, such a device is robust and reliable, making it feasible even in continuous operation use reliable. It also no aerosols are generated but the gas is saturated with vapor liquid. It is also essential that the control of heating and humidification of the movement device and the controlled heating is easy to readjust.

p0054Advantageously, the humidification chamber is designed as a sprinkler chamber. In a sprinkler chamber, the liquid is passed through the gas. The temperature of the flowing gas may be, slightly closer to the temperature of the water, with the same results in a saturation of the flowing gas with evaporating liquid. The light emerging from the sprinkler chamber gas is moisture saturated, ie that there is a relative humidity of about 95 - including 100% and has a temperature close to the predetermined water temperature.

p0055Advantageously a filling is provided with a GRO KISSING surface in the shower chamber. The filling is brought about by the constantly over them liquid passing to the same temperature that has the liquid. The filling can thus serve as a buffer to provide at highly fluctuating gas flows and thus greatly changing needs of evaporation energy in the short term energy again for an increased need for evaporation energy available can.

p0056Particularly suitable for this filling has therefore z. B. an aluminum knits or steel wool shown as well as a pack of metal, particularly steel balls. These materials have a high energy storage capacity combined with the property of being able to release energy again quickly.

p0057But there are also other open-pore structures for the filling material imaginable.

p0058It is essential that the filling is chosen so that the volume flow of the breathing gas is fluidically not substantially hindered and therefore also at a maximum volume flow is virtually impossible to establish a significant pressure difference between the inflow and outflow of the gas.

p0059Such filling can be found in a further preferred embodiment also easy from the sprinkler chamber for the purpose of Auswechseins or for sterilization.

p0060Furthermore, it is essential that the movement device for the liquid to move through the gas, which is preferably a pump, which results in their temperature controlled liquid in an amount by the gas and hence, if appropriate, via a filling in of the sprinkling chamber, which is so great that it can provide the energy, both the temperature of the flowing gas to lift, as well as to provide the required evaporation energy substantially. Thus, to achieve that at maximum Volume flow through the sprinkler element the gas flowing through is heated to almost liquid temperature and flows saturated with a relative humidity of almost 100%.

p0061It has proved advantageous to provide the humidifying chamber in certain applications under overpressure.

p0062Thus one has the possibility to a subsequent gas flow generator to perform already humidified air and humidification does not have to take place between the gas flow generator and the patient. This not only dead space (compressible volume) is avoided in the region between gas flow generator and patient, but also an installation of the device in the breathing tube, which runs between gas flow generator and patient, what could there cause an additional adverse pressure gradient.

p0063Also can be moistened a substantially greater amount of gas through the humidification under excess pressure in the device and stored, as in a humidifier, which is arranged in the area of ​​lower pressure between respiratory flow generating apparatus and the patient. This causes to be regarded as positive buffering of heated and humidified gas and thus can be carried out a balancing of short-term fluctuating airflow.

p0064An elaborate scheme is required. This also means a substantial constructive simplification which leads to cost savings.

p0065In order to precisely adjust patients flowing from the gas flow generator gas in the temperature to the required value is further suggested itself to provide the breathing tube with a corresponding heating element that is placed inside the tube, for example. However, it is also possible to incorporate the heating element in particular in the wall of the ventilation tube. The integration of the heating element in the breathing tube has the advantage that the intended heating element in direct contact with the respiratory gas, and can be set directly to the desired final temperature, thus making it easier for heavily fluctuating airflow always a uniform temperature of the gas to the patient have.

p0066It should be mentioned that, for a loaded with excess pressure humidifying chamber, the liquid and therefore also the humidification is set to a temperature which is chosen such that and also after the subsequent relaxation of the moisture-enriched and heated gas to ventilation or ambient pressure at a desired temperature (temperature ventilation) a defined humidity is achieved. This is in ventilation cases preferably also near saturation. In principle, the temperature is in the over-pressurized gas humidification chamber thereby both depending on the pressure prevailing in the humidifier pressure as well as the patient side of the desired temperature and the desired relative humidity on the patient side of a breath. Depending on the application the possibility to the patient and lower relative humidities be desired than 100%.

p0067It lies also in the context of the invention, the pressure to vary with fluctuating gas streams to fluctuations according to offer now on the patient side facing the relaxation constant tempered and humidified breathing gas.

p0068For the liquid, which is not needed for humidification of the respiratory gas itself, but merely serves to its heating and thereby loses temperature in the sprinkler element, is provided in a preferred embodiment, return it to the liquid reservoir. From there, they can be supplied to the sprinkler element again after re-heating above the regulated heating.

p0069In such a circuit formed thereby, a filter is preferably integrated, is guaranteed by the that both the circulating liquid and the breathing gas in essentially be kept sterile.

p0070In a preferred embodiment, the liquid reservoir having the controlled heating of the liquid pressure and is connected via a pump (as a moving device for the liquid) to the sprinkler element. By this pump is controlled, the amount of the circulated liquid can be adapted to the respective requirements. By optionally provided in the circulation nor a pressure reducer, uninterrupted operation of tempering and humidifying can be possible even when under pressure humidification while a necessary refilling of liquid into the liquid reservoir.

p0071Of course, the Berieselungsbefeuchter described can also be used in low pressure areas. The outlined advantages are retained. However, it may be that this will result in unwanted dead spaces at integrating in a respirator.

p0072An alternative embodiment, as the movement device for the fluid pump not to but one in the liquid in the liquid reservoir partially immersed rotating body. In this it is preferably a stack of spaced plates that rotate about a horizontal axis and thereby drag liquid from the liquid reservoir into the gas stream where the liquid then evaporates and results in a moistening of the gas. Such a device may issued particularly compact are formed and the rotation of the disk pack is very easy to control via an electric motor, which can quickly respond to different needs for liquid gas humidification für.die even with fluctuating gas streams.

p0073Otherwise, the device is characterized essentially by the fact that compliance with the target parameters can be achieved by a simple to implement monitoring of the liquid level in the liquid reservoir and the temperature and pressure in the humidification chamber together with a measurement of temperature and optionally relative humidity of a supplied to a patient breathing gas.

p0074Further advantages and features of the invention will become apparent from the following description of exemplary embodiments. It shows

p00751 shows the basic diagram of a device for heating and humidification of the gas for ventilating a patient with a humidification under pressure;

p0076Figure 2 shows an alternative embodiment of an apparatus for heating and humidification of gas without a high-pressure region; 3 shows another alternative embodiment with a moving device in the form of a plate stack.

p00771 shows an embodiment of a Befeuchtύngsvorrichtung invention, in this case, positioning in front of the gas flow generator.

p0078In the illustrated embodiment, the respiratory gas is taken from a reservoir 1, for example a compressed gas cylinder or a compressed gas line. This usually very dry compressed gas is supplied via a humidifier 2 a gas flow generator. 3 Here, the supplied breathing gas to a pressure (breathing gas level) which is required for a ventilator or a breathing therapy and some may be above the ambient pressure. The respiratory gas is then passed through a temperature-controlled connected to the gas flow generator, heated breathing tube 4 to a patient. 5

p0079The lead from the respiratory gas flow generator 3 to patient 5 takes place with very little compressible volume of the respiratory system.

p0080It is important that the delivered to the patient breathing gas constant and exactly a set humidity and

p0081including temperature, typically near saturation, ie almost 100% at a Temperature of about 37 ° C. In addition, the ventilation of the patient must be carried out without interruption.

p0082For this purpose, the humidifier 2 is fed via a line 6 heated liquid comprising water from about 72 ° C is, in this embodiment, the passes in the humidifier 2 into an annular chamber 7th Incidentally, when this water is mentioned, it should be pointed out once again that the use of other suitable liquids is possible, which can be selected due to its knowledge of the skilled person. Also, the liquid or in the embodiment described here, can the water medications above are added, without this being mentioned separately below.

p0083From the annular chamber 7 the tempered water running over a sieve bottom 8 into a sprinkling chamber 9 which contains a filling 10th This filling consists in this embodiment of solid structural elements having a large surface area and large recesses.

p0084While the water from the annular chamber 7 via the large surface down trickles into the bottom chamber 11 of the humidifier 2, heated and wetted it the filling 10. At the same time flows from the reservoir 1 coming breathing gas in the opposite direction through the packing 10. It warms this breathing gas and simultaneously absorbs moisture, so that it can be nearly saturated passed through a collection chamber 12 for gas flow generator. 3

p0085It should be noted at this point that the humidifier volume flow supplied to heated water is considerably higher than the volume flow, which would ter required in the humidifier on the saturation of the respiratory gas flow with moisture. It is thereby achieved that the contact area of ​​gas and liquid will not significantly cool down, whereby the required temperature increase in the respiratory gas stream is assured.

p0086In the example shown here, the above-described operation takes place under pressure, ie, the water and thus the breathing gas have a pressure of about 4.5 bar at a temperature of about 72 ° C.

p0087Due to the expansion of the breathing gas of about 4.5 bar at about 72 ° C to slightly above ambient pressure, and cooling to a temperature of about 37 ° C, the respiratory gas will retain its relative humidity of almost 100%. There are humidifiers other temperature / pressure combinations possible, it is ensured that even after the relaxation of respiratory pressure level has the breathing gas at the set target temperature, the target humidity in accordance with the predefined parameters.

p0088As already explained, the humidifier 2 is the liquid that is sprinkled over the filling 10, collected in the bottom chamber 11th From here it flows, controlled by a valve 13, through a return line 14 to a storage tank 15. In the return pipe 14 while a pressure reducer 16 is provided so that the reservoir 15 is not pressurized as such. In the illustrated embodiment, the pressure reducing valve is designed as a throttle.

p0089In reservoir 15, the water temperature is maintained in the present example here at 72 ° C on a regulated heater 17, and such a temperature control is relatively simple constructive solutions. The thus heated water is then pumped through an optional filter 18 by a pump 19 through line 6 into the annular chamber 7 of the humidifier. 2

p0090The optional filter 18 ensures in this case that the circulated water is free from particles and microorganisms and thus also the gas flow generator 3 respiratory gas supplied can be considered essentially as a germ-free.

p0091By the pump 19 and the valve 13 and the pressure reducer 16, the reservoir 15 can be formed without pressure and can always be refilled.

p0092An alternative embodiment is shown in FIG 2. Here, the humidifier 2 as in the processes described by the prior art between the gas flow generator 3 and the patient 5 is switched.

p0093To keep the compressible volume and the size small, the device in the ventilation technology available gas currents (0 to 180 l / min) and on standard-compliant humidification is designed.

p0094The humidifier 2 is fed via a line 6 tempered liquid, in turn, water of about 37 ° C is, in this embodiment, the passes in the humidifier 2 in a distribution 7th

p0095From the distribution chamber 7 the tempered water running over a sieve bottom 8 into a sprinkling chamber 9 which contains a filling 10th This filling consists in this embodiment of solid structural elements having a large surface area and large recesses. In order to simplify the device is conceivable to dispense with the filling 10 and let the exiting from the sieve bottom 8 liquid droplets simply fall through the sprinkler chamber. 9 Doing so may be considered to be advantageous for the purification and treatment, it must however be remembered that the same requirements, the volume of irrigation chamber and the circulated amount of liquid per time are on the Humidification may be much larger.

p0096While the water from the distribution chamber 7 via the large surface downwardly trickling in the bottom chamber 11 of the humidifier 2, heated and wets it, the filling 10. At the same time flows from the gas flow generator 3 coming breathing gas in the opposite direction through the packing 10. In this case, this respiratory gas heated and simultaneously absorbs moisture, making it virtually saturated with a relative humidity of about 95 - 100% can be passed via the collection chamber 12 to the patient. 5

p0097To avoid condensation, heated breathing tube 4 is preferably a technologically known, regulated employed. It is important that no part of the wall in the region of the gas stream is colder than the saturation temperature of the gases in order to prevent condensation. Usually, the gas is heated a little in this breathing tube 4, in order to prevent, for example at 40 ° C on the final leg to the patient, especially the unheated tube condensation.

p0098It should be noted that depending on the operating principle of the respective gas flow generator device 3, only one ventilation tube 4, or more are used, which in this case possibly also the air exhaled by the patient can be supplied to the gas flow generator. In these cases, the above embodiments relate to the need or the

p0099Possibilities of hose heater on all other tubes and tube sections, in which the condensation problem may exist.

p0100As explained above, in the humidifier 2 is the liquid, which is trickled over the filling 10, collected in the bottom chamber 11, which functions as a liquid reservoir.

p0101Here the liquid is maintained at a water temperature in this example here of 37 ° C with a controlled heating 17 wherein such a temperature control is relatively simple constructive solutions. The thus heated water is pumped back through an optional filter 18 by a pump 19 through the duct 6 into the distribution chamber 7 of the humidifier second The optional filter 18 ensures in this case that the circulated water is free from particles and microorganisms and therefore the patient 5 respiratory gas supplied essentially can be considered sterile. Alternatively or additionally, the device may be equipped with an antimicrobial surface.

p0102A liquid reservoir 20, for example an infusion bottle, can be regulated in the bottom chamber 11 at a constant level by means of a valve 21 of liquid level. For this may be especially designed as a float valve, this valve. It is important that the hydrostatic pressure difference between the liquid reservoir 20 and the bottom chamber 11 is always greater than the höchstvorkommende ventilation pressure. In practice, this process reveals a positioning of the reservoir 1 m above the bottom chamber recommends in mind..

p0103A further valve 22 serves as a bypass valve between the gas inlet and gas outlet of the humidifier sawn 2. This ensures that at too high a differential pressure, for example by a defect in the humidifier, the ventilation is not obstructed, and thus serves to patient safety.

p0104An integrated into the collection area 12 falls 23 excess and entrained in the air water is separated and recycled to the bottom chamber 11th

p0105To regulate the humidification process and monitors the performance of the control and monitoring device 29 to the humidifier 2 and the patient 5 through various sensors and control lines in communication. Over the temperature sensor 24 can be embodied as commercially available temperature sensor which, for example, the patient's temperature is determined. This may go down as target for the humidification process. Alternatively, this target temperature can also be specified by the communication with another device, such as a surveillance monitor. About a further temperature sensor 26, the liquid temperature is detected and then adjusted with the heater 17th

p0106The third temperature sensor 25 detects the temperature of the incoming gas. At an excessively high increase of the liquid level in the bottom chamber 11 as a result of a failure of the valve 21 or a failure of the pump 19, a control and monitoring device 29 can detect the liquid too high levels over the temperature change of this sensor 25th In this error case, a bypass valve 22 opens, then at a temperature sensor 27, which detects the temperature at the gas outlet, a significant decrease in temperature is to be measured. This security mechanism can be tested by targeted switching off of the pump 19 and the consequent increase of the liquid level and. A firmly connected to the transponder 28, the humidifier 2 control and monitoring unit 29 to the humidifier 2 is connected in order to identify and monitor in terms of its life it.

p0107In the control and monitoring device 29 may also be the power of the pump 19 are monitored. Since power consumption is related to the height of the liquid level in the bottom chamber 11, so that may be a too low liquid level, eg due to an empty storage tank 20 or a defective valve 21, or a lack of liquid circulation, for example by a blockage of the sieve bottom 8, be recognized.

p0108Alternatively, an arrangement according to Figure 3 would be conceivable:

p0109Here is the humidifier 2 according to figure 2 between Atemstromerzeugungs- unit 3 and 5. The patient fluid is located in a bottom chamber 11 and is controlled by the heater 17 at a constant temperature.

p0110The liquid level in the bottom chamber 11 is held in accordance with Figure 2 by reservoir 20 and valve 21 at a constant level.

p0111Solid structural elements of the exchange element 30 appear cyclically, in particular by means of rotation, at least partially so into the liquid that this is done a sufficiently frequent exchange of the water in the contact area. This allows the amount of entrained during immersion liquid by the geometric design of the structural elements substantially affect, for example can be increased by a high rotational speed of energy transport by radial ribs oa Furthermore.

p0112In the described embodiments, as shown in FIGS 1, 2 and 3 as well as correctly dimensioned a highly fluctuating and intermittent flow of gas substantially at a constant temperature, and saturation can be made without for example the risk of overheating of the gas after interruption or too low humidity in sudden high gas flow.

p0113For the inventive solution of the problem it is necessary for that purpose, to dimension the contact area of ​​liquid and gas so and provided with such a geometric structure that almost completely take place at the maximum provided for in the application peak gas flow of the target material and energy exchange can. This dimensioning can be tested by the maximum envisaged peak gas flow rate through the Inventive device is passed. When correctly dimensioning the gas temperature corresponds, after flowing through the humidifying chamber near the liquid temperature before they enter the humidification chamber.

p0114The entrainment of water droplets in the gas stream will take appropriate measures to prevent (eg enlargement of the flow cross-section).

p0115By connecting heated hoses for further transport of the gas, the condensation in the hose can be effectively prevented.

p0116If relative humidity is desired by less than 100%, so this can be achieved through the downstream connection of a suitable heating element for the humidified gas: The gas is brought in the humidifier according to the invention on the temperature and saturation, the absolute content does humidity requirements. About a downstream gas heating or by mixing with dry gas, the gas leaving the humidifier is then brought to the actual target temperature and relative humidity target. This is the generation of different gas temperatures and humidities realized.

p0117The device is not only suitable for the ventilation technology, but is for all applications in which clean a variable gas flow of particles and / or to bring to a constant temperature and humidity. Examples are eg the insufflation of gases into body cavities (eg C0₂ at laparoscopy), the provision of breathing gases for breathing applications (eg paint), inhalation applications of all kinds, the air conditioning of rooms (eg buildings, vehicles, aircraft, ...) either alone or in combination with air-conditioning, etc.