ES1296246U - Non-invasive ventilation system (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Non-invasive ventilation system (1) comprising: - at least one flow generation device (4) coupled to at least one source of medical gases (2); - a recirculation circuit (10) for the recovery of gases not breathed by a patient, in addition to those expired by the patient; - said recirculation circuit (10) comprising a suction and purge conduit (11), suitable for equalizing the pressure inside said recirculation circuit (1); - an interface element (7) that fully or partially covers the patient's airway; - at least one carbon dioxide adsorption element (13) located inside said recirculation circuit (10) and suitable for purifying said gases exhaled by the patient. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

NON-INVASIVE VENTILATION SYSTEM

Scope

The present invention refers to a system for non-invasive ventilation, especially suitable for therapies with continuous positive pressure supply equipment ( Continuous Positive Airway Pressure, CPAP) or high-flow nasal cannulas (HFNC).

The aforementioned system finds a useful application in particular, but not exclusively, in the field of equipment for medical treatment in hospital settings, but it can obviously also be used in the home setting and in mobile emergency units.

state of the art

It is known that in the present sector non-invasive ventilation is a therapeutic treatment in which, through specialized devices that end in masks, helmets or high-flow nasal cannulas (HFNC), the patient is provided with ventilatory support in the upper airways.

The field of application of CPAP equipment is very wide; in some cases they are used in an out-of-hospital setting to deliver a flow of pressurized oxygen-air mixture through a tube and a face (or nasal) mask. The air pressure, in its case enriched with oxygen, makes it possible to keep the airways open to improve the clinical conditions of a patient suffering from sleep apnea, a disorder in which the upper airways tend to fold until they become obstructed during the sleep phases. deeper sleep, causing a sudden awakening of the subject. Another clinical application consists in the treatment of acute respiratory failure, due to various causes, in which positive pressure prevents the lung cavities (alveoli) from closing or collapsing.

CPAP equipment is also used in the neonatal setting through multiple interfaces that fully or partially adhere to the airways.

A non-invasive ventilation modality for adult patients that is most common in Instead, the pre- or intra-hospital setting provides for a so-called free-flow operation, in which the inspired gas is subsequently released into the external environment, directly or through a corresponding expiratory valve that puts the entire interface under positive pressure and, therefore, , the upper airways of the patient.

However, the dispersion in the environment of the gas mixture rendered useless by free-flow ventilation leads both to a high consumption of the gas itself and, in the event of the presence of potential harmful/infectious agents, to a possible contamination of the environment and to a transmission of the pathogen to healthcare personnel.

For this reason, a recirculation circuit can be used to obtain an operating mode called "closed circuit" that allows the gases not consumed by the patient to be reused.

Naturally, these gases are not immediately suitable for reuse, since they are mixed with the gases exhaled by the patient himself.

Therefore, one objective of the present invention is to devise a "closed circuit" system that allows the collection of excess gases and those expired by a patient with the aim of reusing them, after appropriate treatment, for feeding the generator. flow.

Another object of the invention is to provide a system that guarantees the longest possible autonomy of use.

Yet another objective is to provide a system that is as compact and light as possible in comparison with the ventilation systems present in the state of the art.

Additionally, an objective of the invention is to provide a system for treating excess gases and expiration of the regenerative type.

It is also an object of the invention to provide a user-friendly system for an operator.

Lastly, it is an objective of the invention to devise a system that can be easily implemented inside already existing equipment.

Summary of the invention

The solution idea on which the present invention is based is to provide a system that also provides efficient purification of exhaled gases by the patient subject to non-invasive ventilation.

The aforementioned technical problem is solved by means of a non-invasive ventilation system that comprises at least one flow generation device coupled to at least one source of medical gases, a recirculation circuit for the recovery of gases supplied in excess and those expired. by a patient, comprising a suction and purge conduit, suitable for equalizing the pressure inside this recirculation circuit, an interface element that completely or partially covers the patient's airways, at least one carbon dioxide adsorption element located inside the recirculation circuit and suitable for purifying the gases exhaled by the patient.

Advantageously, the system according to the invention makes it possible to obtain, at the outlet of the adsorption element, a mixture of air, enriched with oxygen and/or another gas for medical use, suitable for completely or partially feeding the flow generation system.

Preferably, the carbon dioxide adsorption element comprises soda lime, particularly in the form of cells or cartridges that can be easily replaced.

Advantageously, the use of soda lime allows an effective reduction of the CO ² present in exhaled gases.

More preferably, this soda lime has a percentage of sodium hydroxide greater than 1 and a density greater than 70 g/ml.

Therefore, a higher adsorption efficiency is obtained with the same volume.

Advantageously, this special type of soda lime allows the adsorption properties of the adsorption element to be increased, thus providing better adsorption and better air quality.

Even more preferably, the soda lime used in the adsorption element has a granular configuration with hemispherical granules.

Advantageously, this guarantees a uniform adsorption and a greater resistance to abrasion, therefore reducing the generation of dust or the accumulation of decomposition products in case of accidental drying of the soda lime.

Alternatively, the carbon dioxide adsorption element comprises a lithium-based cell. Alternatively, the carbon dioxide adsorption element may comprise zeolites, solid amines or similar chemical compounds capable of adsorbing CO2.

Advantageously, this solution is extremely compact and also guarantees a high autonomy of use.

Still alternatively, the carbon dioxide adsorption element comprises a solid polymer matrix element.

Advantageously, this solution makes it possible to obtain good performance, apart from the fact that it is very safe, since the adsorption performance provided is highly predictable and is constantly repeated over time.

Still alternatively, the carbon dioxide adsorption element comprises a battery comprising carbon nanotubes for the adsorption of carbon dioxide in the recharging phase.

Advantageously, the present solution is based on the binary affinity between adsorbent and CO2, which allows capturing carbon dioxide of any concentration and allows its release in any carrier flow.

Preferably, the carbon dioxide adsorption element is a double or triple cell system, to allow continuous operation of the ventilation system even in the phase of replacement or regeneration of a cell of the adsorption element.

Advantageously, this allows a controlled increase in performance.

In addition, the system according to the invention can also provide an automatic switching unit, capable of recognizing the saturation reached by a cell and consequently diverting the flow of the mixture to be filtered towards a cell that is not yet saturated.

Therefore, when using a system with double or multiple cells, it is possible to guarantee a continuity of operation of the system: when one of the cells reaches saturation it is excluded from the circuit, a different one that is not yet saturated replaces it, while the system continues to function without interruption.

Still preferably, the carbon dioxide adsorption element is a regenerable element with application of a flow of heated air.

Specifically, a fan associated with a heating resistance is used, which generates a flow of heated air in functional coupling. This flow of heated air forcefully crosses the cell, carrying with it the CO ² released by the adsorber as a consequence of the heating. In this way, therefore, the purification and regeneration of the cell occurs. The parameters to control to obtain the aforementioned regeneration are only the air flow, its heating temperature and the regeneration time.

The regenerative element can comprise an element that contains zeolites, solid amines or similar chemical compounds capable of both adsorbing carbon dioxide and releasing it depending on the fact that they are subjected to suitable stimuli, such as the increase in temperature by means of a flow of hot air or the application of Direct heat through thermal resistance.

This solution also advantageously makes it possible to obtain a very high adsorption efficiency inside a very compact structure.

In case there is a double or multiple cells system, as mentioned above, the system according to the invention can also comprise the automatic switching unit and, therefore, it is possible to foresee the regeneration of the already saturated cell while the The system continues to work by passing through a cell that is not yet saturated and thus optimizing the operation, avoiding forced downtime.

Therefore, advantageously, this solution makes it possible to obtain great autonomy, optimum efficiency, a much lower ecological impact and high profitability.

Additionally, an emergency unit is provided that excludes recirculation in the event that operating anomalies are detected inside the system.

Still preferably, the non-invasive ventilation system additionally comprises an electronic device for monitoring the adsorption decrease.

Advantageously, this solution, which is an alternative to the use according to the state of the art of a staining variation of an exhausted adsorbent, is more precise in signaling the detection itself and guarantees greater safety for the patient.

Preferably, the system according to the invention also includes an air intake port from outside suitable for regulating the quantity of recirculated gas inside the closed circuit.

Advantageously, the present solution allows a correct partialization of the incoming air by dosing the mixture.

Still preferably, the system according to the invention also comprises an isolation and/or condensate collection filter 14.

Advantageously, the present solution relating to the collection of the gas exhaled by the patient and condensate allows an early and accurate diagnosis to be made in non-intubated patients.

Other characteristics and advantages will appear mainly in the detailed description that follows of a preferred, but not exclusive, embodiment of the equipment according to the present invention, in relation to the attached figures given by way of example, but not limiting.

Brief description of the drawings

In these drawings:

• Figure 1 represents a schematic view of a system for non-invasive ventilation comprising an adsorption element according to the invention.

• Figure 2 represents a schematic view of an alternative embodiment of a system for non-invasive ventilation according to the invention.

Detailed description

With regard to the attached figures, 1 indicates globally and schematically a first embodiment of a non-invasive ventilation system, made according to the present invention.

In particular, figure 1 shows a system 1 fed by a source of medical gases 2.

The source of medical gases 2 is therefore connected by means of a supply pipe 3 to a flow generation device 4, preferably a Venturi device 4, by means of an aspiration mouth 5 equipped with a suitable regulator and therefore , suitable for regulating a fraction of recirculation, therefore allowing a correct partialization of the incoming air by dosing the mixture.

The Venturi 4 device is suitable for flow generation for non-invasive ventilation and is shaped as a variable section conduit to take advantage of the Venturi 4 effect.

From the Venturi device 4, therefore, a supply conduit 6 emerges, with which the necessary medical gas mixture is supplied to the patient through an interface 7 by means of an inlet 8, the interface 7 completely or partially covering the airways. of the patient.

The system 1 according to the invention provides for the use in ventilation of a specific interface element 7.

The interface element 7 can be selected from a nasal mask, nasal cannulas, oronasal mask, face mask or helmet for CPAP therapy.

Nothing prohibits, also according to future developments of medical therapies, using different connection elements.

The interface 7 therefore includes an outlet 9 for the gases expired by the patient.

Input 8 can coincide with output 9, with a Y branch directing the flows differently. In particular, when the interface 7 corresponds, for example, to an oronasal mask, a bulge is produced from which the inlet and outlet conduits precisely branch off, where the selection of the conduit is carried out simply by means of a pair of unidirectional valves that direct the flow differently in the phases of inspiration and expiration.

The system 1, which also includes a recirculation circuit 10, in turn comprises at least one suction and purge conduit 11.

The recirculation circuit 10 is configured to recover at least part of the mixture not breathed by the patient, in addition to the expired gases, and is therefore reconnected in correspondence with the Venturi device 4.

The suction and purge conduit 11 is configured to avoid over or under pressure inside the system 1.

Additionally, in the event that there is a depression inside the recirculation circuit 10, and therefore an insufficient amount of mixture in the recirculation circuit 10, this pressure can be relieved by suction directly from outside through the conduit. suction and purge 11.

Therefore, this suction and purge conduit 11 has a double function depending on the direction imposed by the pressure conditions between the interior and exterior of the recirculation circuit 10 itself.

In other words, the suction and purge conduit 11 is suitable for equalizing the pressure inside the recirculation circuit 10.

In other words, in case there is a higher pressure inside the system with respect to the external conditions, a purge function occurs, while in case there is a depression inside the system 1 with respect to the external conditions, an aspiration function is produced that performs a kind of compensation inside system 1.

In an alternative embodiment, which can be seen in figure 2, the system 1 also includes a protruding element 11A associated with the suction and purge conduit 11.

Preferably the protruding element 11A is represented by a corrugated tube element, more preferably double tube, still more preferably double tube coaxial, which, when the aforementioned purge function occurs, is filled with a mixture of gases, while when the suction function occurs, it discharges the aforementioned mixture with which it has been filled into the system. In this way, additional optimization is produced, since the interior of the circuit is not sucked in simple ambient air, but rather a mixture of gases that has positive effects for the patient.

Additionally, inside the recirculation circuit 10 there is also preferably a positive pressure maintenance valve, or PEEP valve, 12.

Valve 12 is a device for maintaining positive end-expiration pressure and is connected to the outlet fitting of the mask, helmet or other CPAP accessories.

The gases leaving the outlet 9 of the interface 7, which also include those expired by the patient, may contain carbon dioxide and, therefore, may not be suitable for reintroduction into the Venturi device 4.

Consequently, a carbon dioxide adsorption element 13 is provided, located inside the recirculation circuit 10, suitable for purifying said gases exhaled by the patient.

Nothing prohibits using more adsorption elements 13 coupled together.

In the represented system 1, the carbon dioxide adsorption element 13 is placed downstream of the suction and purge conduit 11.

According to a preferred embodiment, the carbon dioxide adsorption element 13 comprises soda lime.

Soda lime is made up of a mixture of calcium hydroxide (Ca(OH)2), sodium hydroxide or caustic soda (NaOH), water (H2O). Some compounds contain potassium hydroxide (KOH). The reaction that is obtained is the following:

CO2 H2O ^ H2CO3

H2CO3 2Na(OH) = Na ² CO ³ + H2O heat

Na2COs Ca(OH)2 = CaCOs 2Na(OH) heat

The reaction with KOH instead of Na(OH) is the same. Water is essential at the start of the reaction; The reaction produces 1 mole of H2O for each mole of CO2 neutralized.

Caustic soda is an intermediate compound that is regenerated: it is responsible for the alkaline pH of the initial mixture.

The intergranular space is the volume of gas contained between the granules in the adsorption element 13 after filling. Depending on the type of granules, this space represents 15 to 45% of the internal volume of the adsorber. The compression of the granules makes it possible to reduce the space, bringing the intergranular space and the volume of gas in the granules to approximately 2-4%.

Soda lime contains an indicator that is either an acid or a base that changes with a change in pH. The ideal indicator should change at the beginning of the pH change, be non-toxic and stable.

The dye used is ethyl violet which will change from white to violet.

Alternatively, it is possible to use potassium permanganate, which changes from green to white.

The transformation of caustic soda into carbonate determines the change of the color indicator.

According to a preferred embodiment, the soda lime provides a greater percentage of sodium hydroxide, specifically greater than 1, and a greater density of the product in the same adsorption element, specifically a density greater than 70 g/ml.

Therefore, a higher adsorption efficiency is obtained with the same volume.

According to another preferred embodiment, the soda lime has a granular configuration with hemispherical granules.

The hemispherical shape allows a low level of respiratory resistance, thereby prolonging way the periods of use.

Additionally, this shape guarantees a high CO2 adsorption capacity.

Still further, the hemispherical shape guarantees high resistance to abrasions, thus reducing the formation of dust.

According to an alternative embodiment, the carbon dioxide adsorption element 13 comprises a lithium-based cell.

In particular, in this case calcined solid lithium hydroxide is used, which reacts with carbon dioxide at room temperature.

Specifically, this allows carbon dioxide to be adsorbed from water vapor according to the chemical reaction:

2LiOH CO2 ^ U2CO3 H2O.

Calcined solid lithium hydroxide guarantees reliable performance and confers a high CO2 adsorption capacity, in fact, 1.5 kg of lithium hydroxide absorbs around 1 kg of CO2.

According to a still alternative embodiment, the carbon dioxide adsorption element 13 comprises a solid element of polymeric matrix.

By using a solid element, therefore, the drawbacks of channeling are avoided.

Additionally, carbon monoxide emissions are reduced and accidental caustic dust problems of granular type adsorbents are eliminated.

The adsorbent powders are bound by a polymeric matrix, also allowing cleaner and easier cleaning of system 1.

This solution is suitable for all gas flows.

According to a still alternative embodiment, the carbon dioxide adsorption element carbon 13 comprises a battery comprising carbon nanotubes for the adsorption of carbon dioxide in the recharging phase.

In particular, the adsorption element 13 provides for reactive electroadsorption by solid state oscillation comprising an electrochemical cell that takes advantage of the reductive incorporation of CO2 in the quinones for carbon capture.

An electrochemical cell with a negative electrode composed of carbon nanotubes captures CO2 during charging through carboxylation of reduced quinones and releases CO2 when discharged.

Preferably, the carbon dioxide adsorption element is a double or triple cell system.

Advantageously, moreover, the system according to the invention can also provide an automatic switching unit, capable of recognizing the saturation reached by a cell and consequently diverting the flow of air to be filtered towards a cell that is not yet saturated.

Therefore, when using a double or multiple cell system, it is possible to guarantee the continuity of the system's operation, since when one of the cells becomes saturated it is replaced, while the system continues to function passing through a non-saturated cell. still.

This allows a controlled increase in performance. Continuity of the recirculation system during replacement or regeneration

According to a preferred embodiment, additionally, the carbon dioxide adsorption element is a regenerative element with application of energy, namely a heated air flow.

Specifically, a fan associated with a heating resistance is used, which generates a flow of heated air in functional coupling. This flow of heated air is blown over the coil towards the environment, dragging the CO2 that is released by the adsorber as a result of heating. In this way, therefore, the purification and regeneration of the cell occurs. The parameters to control to obtain said regeneration are only the temperature of the heated air flow and the regeneration time.

In fact, even according to an alternative embodiment, the carbon dioxide adsorption element 13 comprises an element that contains zeolites, solid amines or similar chemical compounds capable of both adsorbing carbon dioxide and releasing it, depending on the fact that they are subjected to to suitable stimuli, such as the increase in temperature through a flow of hot air or direct application of heat through thermal resistance.

Amines, in general, react with CO2 to form the carbamate, according to the reaction:

CO2 2 RNH2 ~ RNH3++ RNHCOO-

In case there is a double or multiple cell system, as mentioned above, the system according to the invention can also comprise the automatic switching unit and, therefore, it is possible to foresee the regeneration of the already saturated cell while the The system continues to work by passing through a cell that is not yet saturated and thus optimizing operation, avoiding forced downtime.

This solution makes it possible to obtain great autonomy, optimal efficiency and, obviously, a much lower ecological impact, as well as high profitability.

Additionally, preferably, the system 1 comprises an isolation and/or condensate collection filter 14.

Therefore, it is possible to collect biological material from the patient's airways in a non-invasive manner.

It is known that the gas exhaled by a subject also contains, in addition to water vapour, various substances that may be indicative of ongoing pathological processes, in particular at the pulmonary level.

The analysis of exhaled gas condensate has been considered promising for the diagnosis of pathogens, neoplasms, and other biological markers.

However, currently, the use of exhaled condensate as a biological sample is not yet a common practice.

Collection of the exhaled condensate sample can be performed when treating the subject invasively, or by exhalation into appropriate instruments.

Therefore, thanks to said filter 14, it is possible to have a device for collecting the exhalation located along the expiratory part of the circuit, preferably upstream of the CO2 adsorber.

This device can be equipped with corresponding supports capable of retaining the condensed exhaled gas for subsequent analysis, that is, recognizing the presence of specific biological markers in real time.

Advantageously, it is therefore possible to carry out diagnoses in a non-invasive manner and well tolerated by the patient.

In addition, it is possible to offer diagnostic instruments that can be used very early during the care process, if necessary, also in an out-of-hospital setting.

According to an alternative embodiment, it is possible to use an electronic device for monitoring the carbon dioxide concentration in order to quickly identify the loss of efficiency of the CO2 adsorber.

In fact, when using caustic soda, there is sometimes the drawback that, after discontinuation of use, a discoloration of the color indicator is slowly determined by exchange of the reaction products from the periphery with the interior of the lime granule. . In this way, the lime can give the impression of still being active, even though it is exhausted. The color of the soda lime used is therefore not a good indicator of its effectiveness.

In a different way, when using the electronic monitoring device, a greater precision and security of the real depletion is obtained.

Advantageously, the system according to the present invention also provides for a recirculation circuit associated with a corresponding carbon dioxide adsorption element to optimize the consumption of medical gas in addition to minimizing the dispersion of the exhaled mixture in the environment.

In this way, advantages are obtained from an economic point of view and from an ecological point of view at the same time.

However, additionally, an emergency unit is provided that excludes recirculation in the event that operating anomalies are detected inside the system.

Additionally, a system is supplied that can be easily implemented in more complex existing equipment without forcing a specific design thereof.

Advantageously, the present system is also applicable in closed-circuit systems that provide for the elimination of excess carbon dioxide, such as, for example, ventilator circuits for invasive ventilation used in systems dedicated to the supply of anesthetic gas. During general anesthesia, it is common to use the closed or partially closed circuit modality, in which a part of the gas exhaled by the patient is reused in order to reduce the consumption of anesthetic gases. Usually, a container of soda lime is placed along the circuit.

When a CO ² meter located along the recirculation loop reaches a preset level, this container must be manually replaced to maintain patient homeostasis, necessitating interruption of the recirculation loop at the time of replacement.

Advantageously, the use of the present invention in the manner described above, of several cells, also defined as "multiple adsorption beds", makes it possible to keep the recirculation of anesthetic gas in operation in the event of a decrease in the CO ² adsorption capacity of one of the beds by diverting the recirculating gas to the non-exhausted bed.In addition, this diversion, as mentioned, can occur automatically without the need for user intervention.

Even more advantageously, the present invention in the form of regenerable "multiple adsorption beds" allows the user not to have to replace any container, since the exhausted one is automatically regenerated to be used again quickly.

The person skilled in the art will understand that the presented embodiment may be subject to additional modifications and variations, according to specific requirements and contingent, all included within the scope of protection of the invention, as defined by the following claims.

Claims (13)

1. Non-invasive ventilation system (1) comprising: - at least one flow generation device (4) coupled to at least one source of medical gases (2); - a recirculation circuit (10) for the recovery of gases not breathed by a patient, in addition to those expired by the patient; - said recirculation circuit (10) comprising a suction and purge conduit (11), suitable for equalizing the pressure inside said recirculation circuit (1); - an interface element (7) that fully or partially covers the patient's airway; - at least one carbon dioxide adsorption element (13) located inside said recirculation circuit (10) and suitable for purifying said gases exhaled by the patient. The non-invasive ventilation system (1) according to claim 1, wherein said carbon dioxide adsorption element (13) comprises soda lime. 3. Non-invasive ventilation system (1) according to claim 2, wherein said soda lime provides a percentage of sodium hydroxide greater than 1 and a density greater than 70 g/ml. 4. Non-invasive ventilation system (1) according to claim 2, wherein said soda lime has a granular configuration with hemispherical granules. The non-invasive ventilation system (1) according to claim 1, wherein said carbon dioxide adsorption element (13) comprises a lithium-based cell. 6. Non-invasive ventilation system (1) according to claim 1, wherein said carbon dioxide adsorption element (13) comprises a solid element of polymeric matrix. 7. Non-invasive ventilation system (1) according to claim 1, wherein said carbon dioxide adsorption element (13) is a regenerable element with application of a flow of heated air. Non-invasive ventilation system (1) according to claim 7, in which said carbon dioxide adsorption element (13) comprises an element of zeolites, solid amines or the like. 9. Non-invasive ventilation system (1) according to claim 1, wherein said carbon dioxide adsorption element (13) comprises a battery comprising carbon nanotubes for carbon dioxide adsorption in the recharging phase. Non-invasive ventilation system (1) according to claim 1, wherein said carbon dioxide adsorption element (13) is a double or multi-cell system, to allow continuous operation of said system (1) even in the phase of replacement or regeneration of a cell of said adsorption element (13). 11. Non-invasive ventilation system (1) according to any one of claims 1 to 10, further comprising an intake of air from outside, suitable for regulating a fraction of recirculation. 12. Non-invasive ventilation system (1) according to any one of claims 1 to 11, further comprising a filter (14) for isolation and/or condensate collection. 13. Non-invasive ventilation system (1) according to any one of claims 1 to 12, further comprising an electronic monitoring device for adsorption reduction.