Respiratory device, method, and a respiratory tube intended therefor

Abstract

A respiratory device comprises artificial respiration means (1) for generating an oxygen-rich inspiratory airflow, which is guided via a respiratory tube (10) to a pulmonary airway of a person involved. Humidification means (20) are provided here to increase a moisture content of the inspiratory airflow. The humidification means comprise a humidification chamber (20) with an atomizer device (25) which is coupled to a liquid conduit (22) in order to receive therefrom a pressurized liquid for spraying and to deliver a spray (26) thereof to the inspiratory airflow. The atomizer device (25) is particularly one of the Rayleigh type. The liquid conduit (22) comprises an electronically controllable valve device (52) which is coupled electronically to a control device (100). The control device (100) generates during operation an independent control signal (B) to the valve device (52), disconnected from a control (A) of the respiration means (1), whereby the valve device (52) opens or closes the liquid conduit (22).

Description

[0001] Respiratory device, method, and a respiratory tube intended therefor

[0002] The present invention relates to a respiratory device, comprising artificial respiration means for generating an oxygen-rich inspiratory airflow, a respiratory tube intended and configured to guide the inspiratory airflow to a pulmonary airway of a person involved, and humidification means which are intended and configured to increase a moisture content of the inspiratory airflow, wherein the humidification means comprise a humidification chamber with an atomizer device in a path of the inspiratory airflow, which atomizer device is coupled or at least couplable to a liquid conduit in order to receive therefrom a pressurized fluid for spraying and to deliver a spray thereof to the inspiratory airflow, and wherein the atomizer device is particularly one of the Rayleigh type, comprising one or more miniscule passages in an otherwise closed membrane layer which receive the pressurized liquid at an inlet and each deliver at an outlet thereof a spray jet of successive droplets of at least substantially equal size. The invention also relates to a method for applying ventilation to a person involved and a respiratory tube intended for all this.

[0003] There is a need in hospitals and other healthcare facilities for ventilator equipment for thereby artificially supporting or even taking over completely the breathing of a person involved. Such equipment is particularly desirable in operating rooms and intensive care departments.A respiratory device used for this purpose usually comprises an advanced respiratory station with a ventilator whereby an oxygen-rich inspiratory airflow is maintained, which is guided via a respiratory conduit to the patient. Such a station often also comprises a return conduit for receiving the expiratory air from the patient and ridding it of carbon dioxide. Once enriched with oxygen, this airflow can then be fed back to the patient again as inspiratory air. Such a respiratory station usually has a plurality of sensors and an extensive user interface with screen whereby the composition of the two airflows is accurately monitored and controlled.

[0004] It is however also desirable in ambulatory situations, such as for instance at the location of the person involved or in the case of accidents and calamities, to have an adequate ventilator in order to thereby be able to artificially support and maintain the breathing of a person involved or a victim. An ambulance will therefore usually be equipped therewith. In these cases the respiration means usually comprise a compressed air or oxygen cylinder with pressure controller from which is taken an oxygen-rich inspiratory airflow, which is guided via a respiratory tube with nozzle to the victim.

[0005] Although the person involved can thus be fed an oxygen-rich airflow, it has been found in practice that the administration of dry air can result in harmful dehydration of the person involved. This in turn will result in undesirable health risks and problems. In order to prevent this the ventilator can be provided with humidification means whereby the relative air humidity of the inspiratory airflow can be controlled before guiding the airflow to the inspiratory system of the person involved.A known humidification device is for instance known from the American patent application US 2010 / 0242963. This known device provides an evaporator device in the respiratory conduit. The evaporator device comprises a water bath with a water supply and heating element which are in open communication with an evaporation chamber through which the inspiratory airflow is guided. The inspiratory airflow thus flows through the evaporation chamber and therein absorbs water vapour escaping from the water bath.

[0006] Although the moisture content of the inspiratory airflow can thus be increased, such evaporation-based humidification devices have drawbacks in practice. Firstly, the heating of the water bath requires some time, and the device thereby has a relatively long start-up and relaxation phase. In addition, the humidification of the inspiratory airflow in such a device is inevitably limited to the maximum relative air humidity at the given temperature of the airflow. At this level the air is saturated and unable to absorb more water vapour.

[0007] Known from International patent application WO 2008 / 117265 is a humidification device which humidifies the air flowing past in mechanical manner. The humidification means of this device comprise a water bath which is in contact with a piezoelectric vibrator element. The vibration generated thereby disturbs the water surface and thus creates an aerosol of water droplets which is delivered to the inspiratory air. A part ofthe liquid thus introduced into the airflow will evaporate and a remaining part will be entrained in the form of liquid droplets.

[0008] An advantage of such a piezoelectric humidifier is that the maximum water assimilation of the inspiratory airflow is thus not limited by the maximum relative air humidity at the prevailing temperature. This is because a part of the aerosol can be absorbed and entrained in liquid form, i.e. as water droplets. A drawback is however that the piezoelectric aerosol generator forms a fixed, integral part of the respiratory device, and this device must therefore always be thoroughly sterilized before a subsequent patient can be treated. What's more, the humidification is not very accurate and is difficult to control with such a humidifier as well. For this reason it is unknown how much moisture is actually delivered and entrained in the airflow.

[0009] A respiratory device of the type described in the preamble is for instance known from International patent application W02023 / 012696 of applicant and does not have these drawbacks, or at least does so to significantly lesser extent. The atomizer device applied therein delivers a particularly accurately dosed spray of minuscule droplets of at least substantially the same size which transition almost immediately into the vapour form in the inspiratory airflow. The evaporation enthalpy absorbed therefor removes the aerosol from the airflow, which can for this purpose be preheated upstream. This airflow is in practice controlled such that it will adhere to the natural breathing of the person involved. The humidification means of the known respiratory device are controlled accordingly in order to thus adhere to the same periodicity, so thathumidification takes place mainly, if not exclusively, during an optionally stimulated breath.

[0010] In this respect ventilation of premature neonates has a number of complicating factors. Compared to invasive ventilation of adults, wherein a dosage in the order of four to eight litres of inspiratory air per minute is adhered to, for instance twelve breaths of 300-800 millilitres every minute, the flow rate in neonatal ventilation is extremely low, i.e. in the order of no more than one to two litres per minute. This is a result of a significantly smaller lung volume in neonatal babies, which is ventilated with significantly smaller breaths of for instance only 20-50 millilitres per breath. The air speeds applied here are furthermore considerably lower. This considerably lower air flow rate results in a correspondingly lower heat capacity and thereby provides insufficient energy, even in the case of an acceptable (pre)heating, to ensure immediate evaporation of the aerosol. Additionally, the breaths of premature neonates are particularly short. In some cases a breath lasts no longer than just a fraction of a second. This makes it difficult, if not impossible, to spray an accurate quantity of moisture.

[0011] It is not unusual during artificial respiration of a person involved to simultaneously administer a medication which supports recovery further. In that case the relevant medication is advantageously administered in pulmonary manner. The human lungs contain more than three million lung alveoli with a total surface area of more than twohundred square metres. Due to this relatively large contact surface of the lungs, the lungs are particularly suitable for rapid and effective absorption of the medication.

[0012] Some pharmaceuticals must be administered in solid form. For this purpose the medication is brought into powder form and introduced into the inspiratory airflow in the form of a powder aerosol, a fine powdery mist, by a dosing device provided for this purpose for a particularly efficient and adequate pulmonary assimilation. The dosing device provides here for accurate control of a dosing of the relevant pharmaceutically active powder mist in the airflow. This pulmonary administration is however less suitable in combination with moist air in that the presence of moisture may result in clumping of the powder, which will thereby not reach a pulmonary penetration depth intended thereby, or at least not wholly, and will disrupt the final actual dosing.

[0013] The present invention has for its object, among others, to provide a respiratory device whereby a precisely controlled dosing of a humidification liquid which is not limited by a relative air humidity can be supplied to an inspiratory airflow, which is also suitable for, among other things, neonatal applications.

[0014] In a further aspect the present invention has for its object, among others, to provide a respiratory device whereby a precisely controlled dosing of a humidification liquid which is not limited by a relative air humidity can be supplied to an inspiratory airflow, which is suitable for pulmonary administration of a solid substance in powder form, particularly comprising one or more pharmaceutically active substances.In order to achieve the stated object a respiratory device of the type described in the preamble has in a first aspect the feature according to the invention that the liquid conduit comprises an electronically controllable valve device which is coupled electronically to a control device, that the control device generates during operation an independent control signal to the valve device, disconnected from a control of the respiration means, whereby the valve device opens or closes the liquid conduit. The independent, intermittent control signal, which is maintained in accordance with the invention, is here disconnected from an optionally stimulated control of the breathing of the person involved. A particular embodiment of the respiratory device has the feature here according to the invention that the control signal is generated asynchronously to a breath of the person involved, particularly with a predetermined at least substantially fixed periodicity and duration. A quantity of moisture can nevertheless be delivered to the inspiratory airflow over time, this being a sufficient quantity on average over this time. With this in mind a further particular embodiment of the respiratory device has the feature according to the invention that the valve device is operated at an interval and duration which are adapted to a flow rate of the inspiratory airflow.

[0015] In neonatal applications use is in some cases made of high-frequency ventilation (HFV), particularly when classical mechanical ventilation is found to be insufficient. In high-frequency ventilation, ventilation takes place at a frequency of for instance 12 Hz, simultaneously to a rather high bias flow of for instance in the order of ten to sixty litresper minute. This bias flow runs directly from the inspiratory respiratory tube to an expiratory conduit, and therefore does not enter the person involved.

[0016] This relatively high bias flow provides for a continuous replenishment and supply of oxygen. The vibrations are intended to open the lungs and to introduce oxygen mainly by means of diffusion.

[0017] Transitioning from classical neonatal invasive mechanical ventilation to high-frequency ventilation has been found to be very difficult in existing systems. There is a high risk of condensation in the circuit ending up in the lungs unintentionally due to the vibrations. The respiratory device according to the invention has been found able to follow this transition without problem by following up the intermittent control signal with a continuous humidification of the bias flow. Both an intended air temperature and air humidity of the inspiratory airflow were maintained here.

[0018] The liquid introduced into the inspiratory airflow has preferably transitioned wholly into the vapour form before entering the inspiratory system of the person involved. In order to enhance this transition a further particular embodiment of the respiratory device has the feature according to the invention that incorporated upstream of the atomizer device in the path of the inspiratory airflow are primary heating means, able and configured to apply and to maintain an increased air temperature in the inspiratory airflow, and more particularly that the primary heating means comprise an electrical heating element through which the path of the inspiratory airflow runs. The increased air temperature thus imparted to the airflow provides an additional energy source for atleast largely covering the evaporation enthalpy required for the evaporation of the liquid spray introduced therein, while the air temperature is maintained above a dew point of the airflow.

[0019] If a capacity of the primary heating means were not already sufficient for this purpose, a further particular embodiment of the respiratory device has the feature according to the invention that the humidification chamber is provided with secondary heating means which are able and configured, at least during operation, to apply and maintain an increased temperature above a dew point of the inspiratory airflow in the humidification chamber, and more particularly that the secondary heating means comprise an electrical heating element which is arranged externally of the humidification chamber, on a wall thereof, and particularly surrounds the humidification chamber. For parts of the spray which did not yet fully evaporate in the airflow heated by the primary evaporating means, the secondary heating means provide an (additional) heating of the humidification chamber in order to make these parts transition into the vapour form after all.

[0020] In the case of a very low flow rate of the inspiratory airflow and / or very low humidification frequency the airflow may provide insufficient evaporation energy to already make the spray transition wholly into vapour during the spraying. In order to nevertheless deliver the introduced liquid at least almost wholly to the airflow and thus keep an absolute moisture content of the airflow under control, a further particular embodiment of the respiratory device has the feature according to the invention that ahydrophilic body is incorporated in the humidification chamber downstream of the atomizer device, particularly a hydrophilic layer on an inner wall of the humidification chamber, more particularly a hydrophilic layer on a bottom of the humidification chamber. The insight applies here that the spray droplets which do not wholly evaporate immediately will drop downward due to the force of gravity. By providing a hydrophilic layer on the bottom these droplets are removed from the airflow and then later supplied therein as vapour with a delay. The above stated secondary heating means support and enhance this vapour delivery.

[0021] With a view to controlled delivery of a powdered pharmaceutical in humidified respiratory air, or at least respiratory air to be humidified, a respiratory device of the type described in the preamble has in the further aspect of the present invention the feature that incorporated or at least able to be incorporated in the path of the inspiratory airflow is a dosing device which is able and configured to deliver a solid substance, particularly a pharmaceutical, in powder form to the inspiratory airflow.

[0022] Prior to such a powder dosing the humidification of the inspiratory air can be switched off or drastically reduced by medical personnel. This is because many commercially available dosing devices, usually referred to as powder inhalers, must be operated manually and arranged in the circuit temporarily. Such a commercially available powder inhaler (DPI) can be placed in the inspiratory air channel wholly or partially via a holder / adapter provided for this purpose. As soon as it is present in the circuit inairtight manner, the powder inhaler can be released manually and the now dry or drier air will cause dispersion of the powder.

[0023] In a particular embodiment the respiratory device has the feature according to the invention that the dosing device is coupled operatively to the control device to receive a further control signal therefrom, and that the valve device and the dosing device are controlled asynchronously by the respective control signals. The dosing device need here not be operated and adapt to the humidification means manually, but is controlled directly and automatically by the control device which is also coupled to the humidification means. With the asynchronous control of the valve device it is in each case achieved that the humidification ceases before the powder is dosed in the inspiratory airflow.

[0024] The insight applies here that the atomizer device applied in the present respiratory device reacts not only particularly accurately but also particularly rapidly to the valve device. Owing to the invention, it is both in a dosing device that is yet to be placed and in a wholly integrated one that the moisture content in the inspiratory airflow can thus be reduced at least temporarily and the dosing device then placed and / or activated in order to introduce a dry powder into the circuit of the inspiratory airflow. After this powder delivery, the original moisture content of the airflow can then be restored again immediately.Switching off or reducing the humidification is substantially only limited by a switching time of the valve device. Owing to this brief relaxation time, especially when the humidification is switched off, a relatively dry airflow can be created temporarily while a solid substance in powder form is distributed therein. A danger of clumping can hereby be precluded or at least limited to a minimum. After administering of the powder, the humidification can be restarted if desired in order to nevertheless achieve an adequate absolute dose of administered moisture.

[0025] In a particular embodiment the respiratory device according to the invention is here characterized in that the dosing device comprises a further atomizer device which is coupled to a powder supply and is able and configured to deliver a cloud thereof to the inspiratory airflow, and that the further atomizer device is controlled asynchronously to the valve device on the basis of the further control signal by means of the control device. The dosing device thus has a supply of the powder substance to be delivered. Successive doses can be delivered thereby, prompted thereto by the control device.

[0026] With a view to an optimal mutual tuning of the humidification means and the dosing device, a preferred embodiment of the respiratory device has the feature according to the invention that the respiratory tube comprises an electronic environmental sensor in the path of the inspiratory airflow, which is able and configured to register an air humidity and / or temperature in a surrounding area and to generate a representative electronic output signal to the control device, and that the control device only controls the dosing device when a relative air humidity detected in the inspiratory airflow isbelow a predetermined threshold value. Feedback by the environmental sensor of a current moisture content and / or the local air temperature to the control device teaches the control device when the moisture content has dropped below a permissible threshold value, after the humidification was ceased, to then first release the dosing device.

[0027] Besides administration of medication in the form of powder or droplets to the inspiratory airflow, an air humidification sensor in the respiratory tube however also has great added value. The intended feedback of the air humidity and / or temperature to the control device can for instance also serve to control the humidification means and / or the dosing device increasingly accurately. This enables the device to control the absolute humidity of the inspiratory airflow even more accurately. The environmental sensor is preferably moreover able to record a temperature of the airflow and generate it to the control device as representative electronic signal. This can then serve inter alia as an additional guarantee for a safe inspiratory air administration to the person involved.

[0028] A method for artificial respiration of a person involved, wherein an inspiratory airflow is supplied to a person involved, whereby oxygen-rich air is intermittently administered in pulmonary manner with an optionally constant first periodicity, adapted to the natural breathing of the person involved, and wherein the inspiratory airflow is humidified by spraying therein a liquid, particularly a liquid rich in water, has the feature according to the present invention that the liquid is sprayed, optionally intermittently, in theinspiratory airflow asynchronously with the first periodicity of the ventilation, particularly at least between the pulmonary administration of oxygen-rich air. The humidification of the inspiratory airflow is thus disconnected from the ventilation frequency, so that sufficient moisture can nevertheless be introduced into the airflow at a low enriched oxygen flow rate as well.

[0029] A particular embodiment of the method has the feature according to the invention that the liquid is intermittently sprayed in the inspiratory airflow with an optionally constant second periodicity, which second periodicity differs from the first periodicity of the ventilation.

[0030] In a further particular embodiment the method has the feature according to the invention that a powder is introduced into the inspiratory airflow during ventilation, while the humidification is interrupted. The powder contains here particularly a pharmaceutically active substance that must be administered in pulmonary manner. Clumping and premature deposition can be counteracted in effective manner by ceasing the humidification during introduction of the powder.ln a preferred embodiment the method has the feature here according to the invention that use is made of the above described respiratory device according to the invention.

[0031] The present invention also relates to a respiratory tube for use with the above described respiratory device and method according to the invention, wherein the respiratory tube comprises an electronic environmental sensor in the path of theinspiratory airflow, which is able and configured to register an air humidity and / or temperature in a surrounding area and to generate a representative electronic output signal to the control device, which respiratory tube is intended and configured to connect the environmental sensor to the control device.

[0032] The invention will be further elucidated hereinbelow with reference to an exemplary embodiment and an accompanying drawing. In the drawing:

[0033] Figure 1 is a first exemplary embodiment of the device according to the invention; and

[0034] Figure 2 is a second exemplary embodiment of the device according to the invention.

[0035] It is otherwise noted here that the figures are purely schematic and not always drawn to (the same) scale. Some dimensions in particular may be exaggerated to greater or lesser extent for the sake of clarity. Corresponding parts are designated in the figures with the same reference numeral.

[0036] The respiratory device shown in figure 1 comprises respiration means 1 in the form of a conventional ventilator as is usually applied for artificial respiration or support of a respiration of a person involved, usually a patient or victim. Such a ventilator 1 is for instance commercially available from the Drager company and, in addition to means for the actual air displacement or delivery, usually also comprises a control device with a user interface, whereby various settings can be set and on which a number of control parameters can be read. Particularly controllable thereby is an airflow 11 which isdelivered to a respiratory conduit 10 coupled to respiration means 1. In the case of supported respiration this airflow is controlled with a periodic control signal A and thereby adapted to the natural breathing of the person involved, which for this purpose is registered by the ventilator.

[0037] In respiratory conduit 10 a respiratory channel extends longitudinally continuously from a coupling to ventilator 1 to a coupling 13 for connection to for instance an endotracheal tube which is introduced into the patient. This channel carries an oxygenrich inspiratory airflow to the person involved. The coupling 13 can also comprise a coupling to an outgoing respiratory tube (not drawn) whereby low-oxygen expiratory airflow can be fed back to the ventilator or otherwise. This expiratory airflow can optionally be rid of carbon dioxide and enriched with oxygen, and then recirculated to the person involved. Another manner of artificial respiration or supporting natural respiration is otherwise also possible instead of invasive ventilation. A continuous nasal ventilation can thus for instance also be applied, in which case the respiratory tube 11 will be coupled to a nasal cannula.

[0038] In order to be able to control a moisture content of the inspiratory airflow 11 humidification means in the form of a humidification chamber 20 and an atomizer device 25 provided therein are provided in the path of the inspiratory airflow 11. In this embodiment an atomizer device of the Rayleigh type is used. Such an atomizer is characterized by an atomizer body 250, for instance of silicon, on which an extremely thin membrane layer 253, for instance of silicon nitride, is arranged. The membranelayer 253 typically has a thickness of one to several microns and one or more minuscule passages 255 with a diameter of similar micron dimensions are present therein. An inlet 22 thereof is fed with a liquid for spraying, which was for instance brought under an increased operating pressure in the order of 0.5 to 3 MPa and supplied by for instance a pump 28. In the liquid channels provided by the passages 255 this liquid flow becomes unstable and breaks up into successive segments. At the outlet 24 these segments form at least substantially identical droplets of a spray jet ejected via the passage 255. Together, the individual spray jets form a spray 261 which is delivered in the inspiratory airflow.

[0039] An aqueous liquid, such as saline or sterile water, is particularly used as the liquid. With atomizer device 25 an absolute moisture content of the airflow 11 is increased, which is in principle not limited to a dew point or prevailing relative air humidity in airflow 11. For full control and regulation of a moisture content of the outgoing airflow 11 the spray 26 of minuscule individual liquid droplets thus delivered in the airflow is preferably converted wholly into the vapour form. The evaporation enthalpy required therefor is at least partially supplied by primary heating means 30, 35 which are provided upstream in the air channel. These heating means 30, 35 provide inside the air channel a thermostatically controllable heat-exchanging surface 35, such as for instance that of a spiral filament, through or along which the air 11 travels before entering the humidification chamber 20. The airflow preheated thereby can contain an increased quantity of water vapour and moreover provides the enthalpy required to make a spray droplet transition wholly into the vapour form. Aided by the almost identical size of thespray droplets, this provides a humidifying method which can be controlled particularly accurately.

[0040] For the electric power supply of the heating means use is preferably made of an inductive current path between the heating means inside the air channel and an electrical connection for a power source externally of the air channel. A wall of the air channel can thus remain intact at this position and need not be interrupted. Moreover, galvanic contacts and other current-conducting elements inside the air channel and the inspiratory airflow carried therethrough can thus be prevented. For a thermostatic control a temperature sensor can optionally be provided on or close to the heatexchanging surface 35.

[0041] The humidification of the airflow is controlled by a control device 100 and roughly the same periodicity is thereby usually imposed on the humidification as the one with which the ventilation itself is supported. The control signal A of the ventilator can for this purpose also be provided to the control device 100 as input signal. The control device 100 is also coupled to the heating means 30, 35 and a temperature sensor and / or air humidity sensor optionally integrated therein or therewith, in order to thus also control and regulate the heat generation of the primary heating means 30, 35. In this way an adequate amount of moisture is introduced into the airflow 11 in each breath and the control device 100 follows the control signal A of the ventilator.In this respect ventilation of premature neonates has a number of complicating factors. Compared to invasive ventilation of adults, wherein a dosage in the order of four to eight litres of inspiratory air per minute is adhered to, for instance twelve breaths of 300-800 millilitres every minute, the flow rate in neonatal ventilation is extremely low, i.e. in the order of no more than one to two litres per minute. This is a result of a significantly smaller lung volume in neonatal babies, which is ventilated with significantly smaller breaths of for instance only 20-50 millilitres per breath. The air speeds applied here are furthermore considerably lower. This considerably lower air flow rate results in a correspondingly lower heat capacity and thereby provides insufficient energy, even in the case of a maximum allowable (pre)heating, to ensure an immediate evaporation of the aerosol 26. Additionally, the breaths of premature neonates are particularly short. In some cases a breath lasts no longer than just a fraction of a second.

[0042] In order to nevertheless also be able to realize a sufficient and accurate humidification of the inspiratory airflow 11 in such a case an electronically controllable valve device 52 is provided in the liquid conduit 22 and connected to the control device 100. The valve device 52 comprises an almost instantaneously reacting shut-off valve and is activated by the control device with an independent intermittent control signal B to open or close the liquid conduit 22. This control signal B is particularly generated asynchronously to, at least independently of, the control signal A whereby ventilator 1 supports the breathing of the premature person involved.The humidification thus takes place with relatively short pulses with a small water content. A sufficient quantity of moisture can nevertheless be delivered to the inspiratory airflow over time. Valve device 52 is here controlled by control device 100 at an interval and duration which are adapted to a flow rate of the inspiratory airflow 11. In order to prevent the airflow 11 from dropping below a dew point as a result of the evaporation heat extracted therefrom secondary heating means 28, which additionally heat the humidification chamber 20 in order to keep the atmosphere therein above the dew point of airflow 11, are moreover provided. In this example these secondary heating means comprise an electrically heated and controllable casing 28 which is arranged externally around the outer wall of the humidification chamber 20 and is coupled to control device 100 and is controlled thereby.

[0043] If a part of the liquid spray 26 has unintentionally not transitioned into water vapour, the droplets in question are collected in a hydrophilic layer 29 which is provided on a bottom inside the humidification chamber 20. This layer has an open structure and is thereby able to absorb the liquid as if it were a sponge and to deliver it to airflow 11 with a delay as soon as a relative air humidity thereof permits it, i.e. has dropped below a maximum of 100%. This is for instance the case between humidification pulses of the control signal B. An adequate and wholly controlled humidification of the inspiratory airflow can thus also be brought about for neonatal and otherwise delicate

[0044] applications.Figure 2 shows a second exemplary embodiment of a respiratory device according to the invention. Corresponding parts that were provided in the first exemplary embodiment are also present in this second exemplary embodiment, and are designated with the same reference numeral. In this example a further atomizer chamber 40 with a dosing device 45, 54 for a powdery composition therein is however provided downstream of the humidification chamber 20. A pharmaceutically active solid substance in powder form can hereby particularly be delivered to the inspiratory airflow 11. The dosing device comprises for instance an atomizer 45 which is coupled to a powder supply 44 and can dispense successive doses thereof. For this purpose the atomizer 45 comprises an actuator 54 which is coupled to the control device 100.

[0045] In this example the actuator 54 is shown schematically as an electronically controllable shut-off valve, although in practice the actuator can particularly comprise a compressed air device for giving off air pulses and / or comprise a driven or at least driveable worm wheel or revolver device whereby a measured dose of the powder is supplied to the atomizer 45 in order to be delivered. The supply container 44 and the actuator 54 are also drawn as separate components in the figure, but these components can in practice also be integrated wholly or partially into a single component with the atomizer 45.

[0046] In order to prevent clumping from occurring here as a result of a humidification of the airflow in the humidification chamber 20 the control device 100 controls the humidification means 25, 52 and the powder dosing device 45, 54 asynchronously relative to each other. In this example control device 100 receives a respiration signal Afrom the ventilator 1 and develops synchronously therewith a control signal B whereby the humidification means 25, 52 are controlled. In this case this is normal support of a person involved, whereby humidification thus takes place in the breath (in). A preheating of the airflow by primary heating means 30 provides sufficient enthalpy to make the minuscule droplets of the spray 26 transition wholly into the vapour form almost immediately. Additional heating of the humidification chamber by means of a secondary heating 28 and / or a hydrophilic absorbent body 29, as in the example of figure 1, can be dispensed with, but can also be applied here if desired.

[0047] In order to dose a powder in the airflow 11 a control signal C is provided to the dosing device 45, 54 by the control device, likewise along with a breath of the person involved, i.e. synchronously with the control signal A that was taken off from the ventilator 1 by the control device. The control device however simultaneously ceases the humidification of the airflow by means of the control signal B of the valve device 52 which shuts off the moisture supply to atomizer 25 before and during the powder dosing. This is represented merely schematically by the control signals A,B,C drawn in control device 100, although the control signals can in practice have a different progression, both in respect of their amplitude and their periodicity and pulse duration.

[0048] Control device 100 is particularly coupled to an environmental sensor 15 with which the distal segment of the respiratory tube 10 is equipped. After the humidification has ceased, the powder delivery to dosing device 45, 54 is not released until a sufficiently low air humidity is registered by the environmental sensor 15. The powder can thus bedelivered in the form of a cloud in almost dry air, without any risk of clumping or deposition against the walls of air tube 10. The environmental sensor 15 is preferably also able to record a temperature of the airflow and exchange it with control device 100 as representative electronic signal as an additional guarantee for a safe inspiratory air administration to the person involved.

[0049] Although the invention has been further elucidated above with reference to only a single exemplary embodiment, it will be apparent that the invention is by no means limited thereto. On the contrary, many variations and embodiments are still possible within the scope of the invention for a person with ordinary skill in the art.

[0050] In the exemplary embodiment use was thus made of an invasive respiration, wherein the person involved is intubated and the respiration is taken over wholly or partially by the device. The respiratory device according to the invention can however also be used for non-invasive respiration, for instance by means of a mask for nose and mouth, on the basis of both CPAP (continuous positive air pressure) and BiPAP (bilevel positive air pressure). With CPAP a constant pressure is applied to the lungs, enabling oxygen-rich air to enter the lungs more easily. With BiPAP an increased air pressure is only provided during inhalation, this facilitating exhalation. Clinicians are increasingly attempting to ventilate in non-invasive manner since this poses less risk of complications.

[0051] In the exemplary embodiments use was made of a dosing device for delivering a dry powder incorporated permanently in the system. The system is however also suitablefor a commercially available, optionally modified third-party dry powder inhaler. In order to have such a DPI disperse the powder a powder capsule must usually be pierced. This takes place in different ways in many commercial DPIs, but usually comprises of pressing a button. In order to use such a DPI with the device according to the invention the dispensing part of the DPI is placed in a holder or adapter provided in the system for this purpose, and the DPI can here optionally be activated beforehand by piercing the capsule. The holder or adapter can also comprise a provision whereby the DPI is activated when it is placed. As soon as the activated DPI is present in the circuit, the subsequent inspiratory breath, which is provided by the respiration means, will already disperse a large part of the powder.

Claims

Claims:

1. Respiratory device, comprising artificial respiration means (1) for generating an oxygen-rich inspiratory airflow, a respiratory tube (10) intended and configured to guide the inspiratory airflow (11) to a pulmonary airway of a person involved, and humidification means (20) which are intended and configured to increase a moisture content of the inspiratory airflow, wherein the humidification means comprise a humidification chamber (20) with an atomizer device (25) in a path of the inspiratory airflow, which atomizer device (25) is coupled or at least couplable to a liquid conduit (22) in order to receive therefrom a pressurized liquid for spraying and to deliver a spray (26) thereof to the inspiratory airflow, and wherein the atomizer device (25) is particularly one of the Rayleigh type, comprising one or more miniscule passages (255) in an otherwise closed membrane layer (253) which receive the pressurized liquid at an inlet (252) and each deliver at an outlet (254) thereof a spray jet of successive droplets of at least substantially equal size, characterized in that the liquid conduit (22) comprises an electronically controllable valve device (52) which is coupled electronically to a control device (100), that the control device (100) generates during operation an independent control signal (B) to the valve device (52), disconnected from a control (A) of the respiration means (1), whereby the valve device (52) opens or closes the liquid conduit (22).

2. Respiratory device according to claim 1, characterized in that the control signal (B) is generated asynchronously to a breath (A) of the person involved, particularly with a predetermined at least substantially fixed periodicity and duration.

3. Respiratory device according to claim 1 or 2, characterized in that the valve device (52) is operated at an interval and duration which are adapted to a flow rate of the inspiratory airflow (11).

4. Respiratory device according to claim 1, 2 or 3, characterized in that incorporated upstream of the atomizer device (25) in the path of the inspiratory airflow (11) are primary heating means (30, 35), able and configured to apply and to maintain an increased air temperature in the inspiratory airflow.

5. Respiratory device according to claim 4, characterized in that the primary heating means comprise an electrical heating element (35) through which the path of the inspiratory airflow (11) runs.

6. Respiratory device according to one or more of the preceding claims, characterized in that the humidification chamber (20) is provided with secondary heating means (28) which are able and configured, at least during operation, to apply and to maintain an increased temperature above a dew point of the inspiratory airflow (11) in the humidification chamber (20).

7. Respiratory device according to claim 6, characterized in that the secondary heating means comprise an electrical heating element (28) which is arranged externally of the humidification chamber (20), on a wall thereof, and particularly surrounds the humidification chamber.

8. Respiratory device according to one or more of the preceding claims, characterized in that a hydrophilic body (29) is incorporated in the humidification chamber downstream of the atomizer device (25), particularly a hydrophilic layer on an inner wall of the humidification chamber (20), more particularly a hydrophilic layer on a bottom of the humidification chamber.

9. Respiratory device according to one or more of the preceding claims, characterized in that incorporated or at least able to be incorporated in the path of the inspiratory airflow is a dosing device (45, 54) which is able and configured to deliver a solid substance, particularly a pharmaceutical, in powder form to the inspiratory airflow (11).

10. Respiratory device according to claim 9, characterized in that the dosing device is coupled operatively to the control device (100) to receive a further control signal (C) therefrom, and that the valve device (52) and the dosing device (45, 54) are controlled (C) asynchronously by the respective control signals (B, C).

11. Respiratory device according to claim 9 or 10, characterized in that the dosing device (45, 54) comprises a further atomizer device (45) which is coupled to a powder supply and is able and configured to deliver a cloud thereof to the inspiratory airflow (11), and that the further atomizer device (45) is controlled asynchronously to the valve device (52) on the basis of the further control signal (C) by means of the control device (100).

12. Respiratory device according to claim 9, 10 or 11, characterized in that the respiratory tube (10) comprises an electronic environmental sensor (15) in the path of the inspiratory airflow (11), which is able and configured to register an air humidity and / or temperature in a surrounding area and to generate a representative electronic output signal to the control device (100), and that the control device (100) only controls the dosing device (45, 54) when a relative air humidity detected in the inspiratory airflow is below a predetermined threshold value.

13. Respiratory tube (10) for use with the respiratory device of claim 10, characterized in that the respiratory tube comprises an electronic environmental sensor (15) in the path of the inspiratory airflow, which is able and configured to register an air humidity and / or temperature in a surrounding area and to generate a representative electronic output signal to the control device (100), intended and configured to connect the environmental sensor (15) to the control device (100).

14. Method for artificial respiration of a person involved, wherein an inspiratory airflow is supplied to a person involved, whereby oxygen-rich air is intermittently administered in pulmonary manner with an optionally constant first periodicity, adapted to the natural breathing of the person involved, and wherein the inspiratory airflow is humidified by spraying therein a liquid, particularly a liquid rich in water, characterized in that the inspiratory airflow is humidified, optionally intermittently, asynchronously with the first periodicity, particularly at least between the pulmonary administration of oxygen-rich air.

15. Method according to claim 14, characterized in that the liquid is intermittently sprayed in the inspiratory airflow with an optionally constant second periodicity, which second periodicity differs from the first periodicity of the ventilation.

16. Method according to claim 14 or 15, characterized in that a powder is introduced into the inspiratory airflow during ventilation, while the humidification is interrupted.

17. Method according to claim 14, 15 or 16, using the respiratory device according to one or more of the claims 1-12.

Images