FR3137841A1 - NO delivery device with emergency dosing system - Google Patents

Abstract

Title of the invention NO delivery device with emergency dosing system The invention relates to an NO delivery device (1) for supplying a NO-containing gas comprising an NO injection line (111), a flow measuring device (112) and a valve device (113). The valve device (113) is normally closed. An emergency line (201) connected to the injection line (111) includes a normally open emergency solenoid valve (202) and a flow control device (210). Control means (130) control these elements. In the event of a malfunction of the control means (130), the emergency solenoid valve (202) switches to the open position, while the valve device (113) switches to the closed position. The flow control device (210) supplies gas at a preset emergency gas flow rate, determined from gas flow measurements provided by the flow measurement device (112), during normal operation of the device (1). , before the malfunction. Gas supply installation comprising such a NO delivery device (1) and a medical ventilator (2). Abstract figure: Fig. 1

Description

NO delivery device with emergency dosing system

The invention relates to a device for delivering gaseous nitrogen monoxide (NO) to a patient comprising an emergency NO dosing system, and intended to be connected to the patient circuit of a mechanical ventilator, i.e. i.e. a medical device for administering gas to a patient, which makes it possible to supply gas at a prefixed flow rate in the event of a malfunction, in particular of the control means.

NO is a gas which, when inhaled, dilates the pulmonary vessels and increases oxygenation by improving gas exchange.

The properties of NO are used to treat different medical conditions, such as Pulmonary Hypertension of the Newborn or PPHN (for Persistent Pulmonary Hypertension of the Newborn ), Acute Respiratory Distress Syndrome or ARDS observed mainly in adults or even pulmonary hypertension in cardiac surgery, as taught in particular by EP-A-560928, EP-A-1516639 or US-A-10,201,564.

Usually, a small quantity of NO gas (ie a few ppm vol.), diluted in nitrogen (N ₂ ) is injected into a gas flow containing oxygen (O ₂ ) which is then inhaled by the patient. The concentration of NO, which corresponds to a dosage, is determined by the doctor or the like. Typically, the gas containing the O ₂ is typically an N ₂ /O ₂ mixture or air, such as medical grade air. In general, the concentration of NO in the gas inhaled by the patient is between 1 and 80 ppm by volume (ppmv), depending on the population treated, ie newborns or adults, and therefore the disease to be treated.

The gas inhaled by the patient can be delivered through an NO delivery device associated with a mechanical ventilator, as described by US-A-5,558,083. The NO delivery device is fluidly connected to one or more gas cylinders containing a mixture of N ₂ /NO whose NO concentration can typically be between 200 and 800 ppmv. Generally, the NO delivery system comprises an NO injection module placed in the inspiratory branch of a patient circuit fluidly connected, on the one hand, to the mechanical ventilator and, on the other hand, to a respiratory interface delivering the NO-enriched gas to the patient, for example a breathing mask, a tracheal intubation tube or the like.

The NO delivery system also includes a flow sensor which measures the gas flow delivered by the mechanical ventilator (ie air or N ₂ /O ₂ mixture) in order to determine the quantity of NO to be delivered to respect the dosage set by the doctor .

The NO delivery system can ensure the NO dosage by means of a proportional solenoid valve delivering a continuous flow of gas containing NO, which is associated with a flow sensor, the two components being arranged in the delivery system, as well as an injection line connected to the NO injection module, as described in US-A-5,558,083.

Other systems are available where the proportional solenoid valve is replaced by a plurality of “all or nothing” type solenoid valves, delivering the gas intermittently, that is to say in the form of pulses, generally at high frequency. , whose amplitude and duration make it possible to guarantee the right quantity of gas circulating in the injection line connected to the NO injection module.

In all cases, known NO delivery systems receive the measurements from the flow sensor placed in the inspiratory branch of the patient circuit and adjust in real time the quantity of NO to be delivered, according to the desired dosage, by controlling the flow of NO. NO in the injection line.

NO being an effective therapeutic agent, that is to say that very low concentrations (i.e. a few ppmv) produce a therapeutic effect, its correct dosage is of critical importance and medical teams must constantly adapt the dosage according to the condition of the patient.

As the patient's condition changes, the NO concentration should be gradually decreased or increased. For example, in a situation of weaning a newborn whose condition is improving, it is usual to gradually decrease the dosage, for example in steps of 1 ppm, until reaching a zero value which then allows the system to be stopped. delivery of NO.

A gradual reduction in the NO concentration makes it possible to avoid the “rebound effect”, which can occur in the event of a rapid variation in the concentration, for example in the event of sudden discontinuation of treatment, with the effect of seriously worsening the condition of the patient.

However, NO delivery systems are sophisticated electro-medical systems susceptible to failures or malfunctions which could have a significant impact on the therapy in progress. For example, a major electronic malfunction or defect, in particular of the control means, can lead to a breakdown of the device and therefore a total stoppage of NO delivery, with the negative consequences mentioned above.

In such circumstances, the device must warn the user by means of an audible alarm signal that rapid action is required, for example to switch to an emergency pneumatic injection mode in order to limit, as much as possible, adverse effects linked to discontinuation of therapy.

Such a switch to emergency mode is usually done by actuation of a rotary button controlling the transition from the normal NO administration mode to an emergency mode, in which for example a continuous delivery of a fixed flow rate of mixture is carried out. N ₂ /NO, ie of the order of 250 mL/min.

• son activation requiert la présence d’une personne ayant autorité pour entreprendre cette action, par exemple un médecin en néonatologie. Il peut ainsi se passer plusieurs minutes avant que cette personne arrive et donc que le dosage de secours ne soit établi, ce qui entraine une discontinuation de la thérapie et expose le patient à un effet rebond.
• ce dosage de secours, i.e. un débit unique de mélange N₂/NO, ne permet pas de garantir que la posologie désirée soit respectée. En particulier, quand le dosage de secours est très inférieur à la posologie souhaitée, le patient peut être exposé à un changement abrupte de concentration et potentiellement sujet à d’importants effets indésirables.
• le dosage de secours est incompatible avec certains types de ventilateurs délivrant de très faibles volumes, tels que les ventilateurs à oscillations hautes fréquence (HFO) car il peut en résulter une concentration en NO inhalée trop élevée pouvant atteindre des niveaux dangereux pour le patient. Dès lors, en cas de traitement du patient avec un tel ventilateur (i.e. HFO), on se retrouve alors sans moyens d’administrer le NO au patient, ce qui entraine les risques susmentionnés liés à l’arrêt brusque de traitement.

However, an emergency dosing mechanism or system is not without risk, in particular for the following reasons:

• its activation requires the presence of a person with authority to undertake this action, for example a neonatology doctor. It may therefore take several minutes before this person arrives and therefore before the emergency dosage is established, which leads to discontinuation of therapy and exposes the patient to a rebound effect.
• this emergency dosage, ie a single flow rate of N ₂ /NO mixture, does not guarantee that the desired dosage is respected. In particular, when the rescue dosage is much lower than the desired dosage, the patient may be exposed to an abrupt change in concentration and potentially subject to significant adverse effects.
• Backup dosing is incompatible with certain types of ventilators delivering very low volumes, such as high-frequency oscillation (HFO) ventilators because it can result in an excessively high inhaled NO concentration that can reach dangerous levels for the patient. Therefore, if the patient is treated with such a ventilator (ie HFO), we then find ourselves without means of administering NO to the patient, which leads to the aforementioned risks linked to the abrupt cessation of treatment.

It therefore appears that the current emergency dosing mechanisms do not guarantee a satisfactory level of safety and that it would be desirable for the patient, in the event of setting up an emergency dosage due to a malfunction. of the NO delivery system, to be able to maintain NO therapy, without interrupting the therapy, and without worrying about the type of ventilator, i.e. HFO or other, with which the NO delivery system cooperates.

In other words, a problem is to be able to maintain a dosage, that is to say treatment of the patient with inhaled NO, even in the event of failure or malfunction of the NO delivery system, in particular a total cessation of operation of the means. control due to a breakdown or power supply fault for example.

• une ligne d’injection de NO pour acheminer le gaz contenant du NO,
• un dispositif à vanne agencé sur la ligne d’injection pour contrôler la circulation du gaz contenant du NO dans la ligne d’injection, ledit dispositif à vanne étant configuré pour être normalement dans une position fermée pour empêcher toute circulation de gaz dans la ligne d’injection,
• un dispositif de mesure de débit agencé sur la ligne d’injection pour opérer une ou des mesures de débit du gaz contenant du NO circulant dans la ligne d’injection,
• une ligne de secours venant se raccorder fluidiquement à la ligne d’injection en amont et en aval du dispositif à vanne, ladite ligne de secours comprenant une électrovanne de secours configurée pour être normalement dans une position ouverte pour permettre une circulation de gaz dans la ligne de secours, et un dispositif de contrôle de débit, et
• des moyens de pilotage, aussi appelés unité de pilotage, configurés pour coopérer avec l’électrovanne de secours, le dispositif de contrôle de débit, le dispositif à vanne et le dispositif de mesure de débit.

A solution according to the invention relates to a device, ie an apparatus, for delivering NO to supply a gas containing NO, typically a NO/nitrogen mixture, comprising:

• a NO injection line to convey the gas containing NO,
• a valve device arranged on the injection line to control the circulation of gas containing NO in the injection line, said valve device being configured to be normally in a closed position to prevent any circulation of gas in the injection line 'injection,
• a flow measuring device arranged on the injection line to carry out one or more flow measurements of the gas containing NO circulating in the injection line,
• an emergency line connecting fluidly to the injection line upstream and downstream of the valve device, said emergency line comprising an emergency solenoid valve configured to be normally in an open position to allow gas circulation in the line emergency, and a flow control device, and
• control means, also called control unit, configured to cooperate with the emergency solenoid valve, the flow control device, the valve device and the flow measurement device.

• l’électrovanne de secours est configurée pour passer en position ouverte pour permettre une circulation de gaz dans la ligne de secours,
• le dispositif à vanne est configuré pour passer en position fermée pour stopper toute circulation de gaz dans la ligne d’injection, et
• le dispositif de contrôle de débit est configuré pour fournir le gaz à un débit gazeux de secours préfixé, où ledit débit gazeux de secours :
  • est déterminé par les moyens de pilotage à partir d’au moins une mesure de débit du gaz fournie par le dispositif de mesure de débit, pendant un fonctionnement normal du dispositif précédant ledit dysfonctionnement, et
  • est préréglé par commande dudit dispositif de contrôle de débit par les moyens de pilotage, pendant ledit fonctionnement normal du dispositif.

Furthermore, in the device of the invention, in the event of a malfunction (ie within the NO delivery device) leading to a cessation of all cooperation with the control means:

• the emergency solenoid valve is configured to move to the open position to allow gas circulation in the emergency line,
• the valve device is configured to go into the closed position to stop any circulation of gas in the injection line, and
• the flow control device is configured to supply the gas at a preset emergency gas flow, where said emergency gas flow:
  • is determined by the control means from at least one gas flow measurement provided by the flow measurement device, during normal operation of the device preceding said malfunction, and
  • is preset by controlling said flow control device by the control means, during said normal operation of the device.

• « ppmv » signifie partie par million en volume,
• « %vol. » » signifie pourcentage en volume.
• « NO » désigne le monoxyde d’azote.
• « N₂» désigne l’azote.
• « O₂» désigne l’oxygène.
• Par « fonctionnement normal » : on entend un fonctionnement habituel du dispositif de délivrance de NO pendant une première période de temps non-nulle, en l’absence de toute panne, dysfonctionnement, défaut ou autre. La première période de temps a une durée de typiquement une à plusieurs minutes, voire heures ou même plus.
• Par « dysfonctionnement », on entend une panne, un dysfonctionnement, un défaut ou analogue, qu’il soit électrique ou d’une autre nature, affectant le fonctionnement normal du dispositif, en particulier empêchant le fonctionnement des moyens de pilotage du dispositif, pendant une seconde période de temps non-nulle, par exemple du fait d’une panne ou dysfonctionnement de ces moyens de pilotage, tel un défaut d’alimentation électrique de ceux-ci. La seconde période de temps a une durée variable, par exemple de quelques secondes à une ou plusieurs minutes, ou même plus.

In the context of the invention:

• “ppmv” means parts per million by volume,
• " %flight. » » means percentage by volume.
• “NO” stands for nitric oxide.
• “N ₂ ” designates nitrogen.
• “O ₂ ” designates oxygen.
• By “normal operation”: we mean usual operation of the NO delivery device during a first non-zero period of time, in the absence of any breakdown, malfunction, defect or other. The first period of time typically has a duration of one to several minutes, or even hours or even more.
• By “malfunction” is meant a breakdown, malfunction, defect or the like, whether electrical or of another nature, affecting the normal operation of the device, in particular preventing the operation of the device control means, during a second non-zero period of time, for example due to a breakdown or malfunction of these control means, such as a fault in their electrical supply. The second period of time has a variable duration, for example from a few seconds to one or more minutes, or even more.

• les moyens de pilotage sont en outre configurés pour, pendant le fonctionnement normal du dispositif, commander l’électrovanne de secours pour qu’elle soit en une position fermée empêchant toute circulation de gaz dans la ligne de secours.
• les moyens de pilotage sont en outre configurés pour, pendant le fonctionnement normal du dispositif, commander le dispositif à vanne pour autoriser une circulation de gaz dans la ligne d’injection et au moins une mesure de débit de gaz par le dispositif de mesure de débit.
• les moyens de pilotage sont en outre configurés pour, pendant le fonctionnement normal du dispositif, contrôler le dispositif de contrôle de débit pour prérégler le débit gazeux de secours à partir d’au moins une mesure de débit du gaz fournie par le dispositif de mesure de débit. Autrement dit, le réglage du dispositif de contrôle de débit se fait préalablement à tout dysfonctionnement, c'est-à-dire pendant que le dispositif fonctionne normalement.
• pendant le fonctionnement normal du dispositif, le dispositif de mesure de débit est configuré pour opérer plusieurs mesures de débit successives.
• pendant le fonctionnement normal du dispositif, les moyens de pilotage sont en outre configurés pour déterminer, par exemple calculer, le débit gazeux de secours à partir d’une ou plusieurs mesures de débit opérées par le dispositif de mesure de débit.
• la ligne de secours vient se raccorder fluidiquement à la ligne d’injection en amont du dispositif à vanne, et en amont ou en aval du dispositif de mesure de débit, de préférence en aval du dispositif de mesure de débit.
• un dispositif de mesure de débit est agencé sur la ligne d’injection en amont ou en aval du dispositif à vanne, de préférence en aval du dispositif à vanne.
• la ligne de secours vient se raccorder fluidiquement à la ligne d’injection par une extrémité amont en amont du dispositif à vanne et par une extrémité aval en aval du dispositif à vanne de manière à bipasser ledit dispositif à vanne.
• il comprend des moyens de mémorisation pour mémoriser au moins une partie des mesures de débit successives opérées par le dispositif de mesure de débit, c'est-à-dire les mesures de débit successives sont mémorisées par des moyens de mémorisation
• les moyens de mémorisation comprennent une mémoire informatique, par exemple un mémoire vive.
• il comprend un système de dosage de secours de NO comprenant la ligne de secours.
• la ligne d’acheminement de NO achemine un mélange gazeux formé de NO et d’azote, de préférence un mélange gazeux NO/N₂(i.e. monoxyde d’azote/azote) contenant entre 100 et 2000 ppmv de NO, typiquement moins de 1000 ppmv de NO, le reste étant de l’azote (et éventuellement des impuretés inévitables)
• l’électrovanne de secours est configurée et/ou pilotée pour être normalement ouverte.
• l’électrovanne de secours est du type tout ou rien.
• les moyens de pilotage comprennent au moins un microprocesseur.
• les moyens de pilotage comprennent une carte électronique portant ledit au moins un microprocesseur.
• la ligne d’injection est raccordée fluidiquement à une ligne haute pression par l’intermédiaire d’un dispositif régulateur de pression, la ligne haute pression et le dispositif régulateur de pression étant agencés dans le dispositif de délivrance de NO.
• le dispositif de délivrance de NO comprend un boitier.
• le système de dosage de secours de NO est agencé dans le boitier, en particulier la ligne de secours et l’électrovanne de secours.
• la ligne de secours vient se raccorder fluidiquement à la ligne d’injection entre le dispositif régulateur de pression et le dispositif à vanne.
• le dispositif à vanne comprend une électrovanne, de préférence une électrovanne proportionnelle.
• le dispositif de contrôle de débit est configuré pour former, constituer ou comprendre un orifice calibré de type proportionnel, c'est-à-dire former un système à orifice calibré proportionnel.
• le dispositif de contrôle de débit comprend un moyen actionneur coopérant avec un élément mobile comprenant un évidement traversant, ledit élément mobile pouvant être déplacé angulairement par le moyen actionneur.
• le moyen actionneur comprend un moteur électrique entrainant un axe rotatif, l’élément mobile étant solidaire dudit axe rotatif.
• le moteur électrique est un moteur pas à pas.
• l’élément mobile est agencé mobile dans un logement interne comprenant un port d’entrée et un port de sortie en communication fluidique avec la ligne de secours.
• l’élément mobile est une sphère, c'est-à-dire sphérique, par exemple une bille ou analogue.
• le logement interne a une forme sphérique complémentaire de celle de l’élément mobile sphérique.
• les moyens de pilotage sont configurés pour piloter le moyen actionneur pour opérer un déplacement angulaire de l’élément mobile entre au moins :
  • une position d’ouverture totale correspondant à un niveau d’ouverture totale de l’orifice calibré du dispositif de contrôle de débit,
  • une position de fermeture totale correspondant à un niveau de fermeture (i.e. obturation) totale de l’orifice calibré du dispositif de contrôle de débit, et
  • au moins une position intermédiaire située entre lesdites position d’ouverture totale et position de fermeture totale correspondant à un niveau d’ouverture partiel de l’orifice calibré du dispositif de contrôle de débit.
• les moyens de pilotage sont configurés pour piloter le moyen actionneur pour opérer un déplacement angulaire de l’élément mobile entre au moins :
  • une position d’ouverture totale dans laquelle tout le débit gazeux amené par la ligne de secours pénètre dans l’évidement traversant de l’élément mobile, c'est-à-dire un débit maximal,
  • une position de fermeture totale dans laquelle aucun débit gazeux ne peut traverser l’évidement traversant de l’élément mobile, c'est-à-dire un débit nul, et
  • au moins une position intermédiaire située entre lesdites position d’ouverture totale et position de fermeture totale, dans laquelle seulement une partie du débit gazeux amené par la ligne de secours pénètre dans l’évidement traversant de l’élément mobile, c'est-à-dire un ou des débits réduits.
• les moyens de pilotage sont configurés pour piloter le moyen actionneur pour opérer un déplacement angulaire de l’élément mobile entre plusieurs positions intermédiaires, angulairement décalées les uns des autres, correspondant chacune à un niveau d’ouverture d’orifice calibré et/ou à un débit de gaz donné, c'est-à-dire des débits réduits compris entre le débit maximal et le débit nul.
• les moyens de pilotage sont configurés pour piloter le moyen actionneur pendant le fonctionnement normal du dispositif, c'est-à-dire préalablement à tout dysfonctionnement, de manière à régler ou ajuster le débit gazeux de secours préfixé.
• les moyens de pilotage sont configurés pour piloter le moyen actionneur pour opérer un déplacement angulaire de l’élément mobile dans une position donnée correspondant au débit de secours préréglé.
• les moyens de pilotage sont configurés pour déterminer une ouverture d’orifice calibré donné correspondant au débit de secours préréglé.
• les moyens de pilotage sont configurés pour déterminer l’ouverture d’orifice calibré donné et/ou le débit de secours préréglé à partir d’une table de correspondance.
• il comprend des moyens d’alimentation électrique alimentant en courant électrique les composants nécessitant de l’énergie électrique pour fonctionner, notamment les moyens de pilotage.
• les moyens d’alimentation électrique comprend des moyens de raccordement au secteur (110/220V) et/ou une batterie ou analogue.
• le dispositif de contrôle de débit du système de dosage de secours de NO constitue un système à orifice calibré proportionnel permettant de régler ou ajuster le débit gazeux de secours préfixé, préalablement à tout dysfonctionnement de l’appareil empêchant toute coopération entre les moyens de pilotage et l’électrovanne de secours, le dispositif de contrôle de débit, le dispositif à vanne et/ou le dispositif de mesure de débit.
• le débit gazeux de secours à partir correspond à la dernière mesure de débit opérée par le dispositif de mesure de débit ayant été opérée avant le dysfonctionnement.

Depending on the embodiment considered, the NO delivery device of the invention may comprise one or more of the following characteristics:

• the control means are further configured to, during normal operation of the device, control the emergency solenoid valve so that it is in a closed position preventing any circulation of gas in the emergency line.
• the control means are further configured to, during normal operation of the device, control the valve device to authorize a circulation of gas in the injection line and at least one gas flow measurement by the flow measurement device .
• the control means are further configured to, during normal operation of the device, control the flow control device to preset the emergency gas flow from at least one gas flow measurement provided by the gas flow measurement device Speed. In other words, the adjustment of the flow control device is done before any malfunction, that is to say while the device is operating normally.
• during normal operation of the device, the flow measurement device is configured to carry out several successive flow measurements.
• during normal operation of the device, the control means are further configured to determine, for example calculate, the emergency gas flow from one or more flow measurements carried out by the flow measurement device.
• the emergency line is fluidly connected to the injection line upstream of the valve device, and upstream or downstream of the flow measurement device, preferably downstream of the flow measurement device.
• a flow measuring device is arranged on the injection line upstream or downstream of the valve device, preferably downstream of the valve device.
• the emergency line is fluidly connected to the injection line by an upstream end upstream of the valve device and by a downstream end downstream of the valve device so as to bypass said valve device.
• it comprises storage means for storing at least part of the successive flow measurements carried out by the flow measurement device, that is to say the successive flow measurements are stored by storage means
• the storage means comprise a computer memory, for example a RAM.
• it includes an emergency NO dosing system including the emergency line.
• the NO conveying line conveys a gas mixture formed of NO and nitrogen, preferably a NO/N ₂ gas mixture (ie nitrogen monoxide/nitrogen) containing between 100 and 2000 ppmv of NO, typically less than 1000 ppmv of NO, the remainder being nitrogen (and possibly unavoidable impurities)
• the emergency solenoid valve is configured and/or controlled to be normally open.
• the emergency solenoid valve is of the all or nothing type.
• the control means comprise at least one microprocessor.
• the control means comprise an electronic card carrying said at least one microprocessor.
• the injection line is fluidly connected to a high pressure line via a pressure regulator device, the high pressure line and the pressure regulator device being arranged in the NO delivery device.
• the NO delivery device comprises a housing.
• the emergency NO dosing system is arranged in the box, in particular the emergency line and the emergency solenoid valve.
• the emergency line is fluidly connected to the injection line between the pressure regulator device and the valve device.
• the valve device comprises a solenoid valve, preferably a proportional solenoid valve.
• the flow control device is configured to form, constitute or comprise a proportional type calibrated orifice, that is to say form a proportional calibrated orifice system.
• the flow control device comprises actuator means cooperating with a movable element comprising a through recess, said movable element being able to be moved angularly by the actuator means.
• the actuator means comprises an electric motor driving a rotary axis, the movable element being integral with said rotary axis.
• the electric motor is a stepper motor.
• the movable element is arranged movably in an internal housing comprising an input port and an output port in fluid communication with the emergency line.
• the movable element is a sphere, that is to say spherical, for example a ball or the like.
• the internal housing has a spherical shape complementary to that of the spherical movable element.
• the control means are configured to control the actuator means to effect an angular movement of the mobile element between at least:
  • a total opening position corresponding to a total opening level of the calibrated orifice of the flow control device,
  • a total closure position corresponding to a total closure (ie obturation) level of the calibrated orifice of the flow control device, and
  • at least one intermediate position located between said total open position and total closed position corresponding to a partial opening level of the calibrated orifice of the flow control device.
• the control means are configured to control the actuator means to effect an angular movement of the mobile element between at least:
  • a fully open position in which all the gas flow supplied by the emergency line enters the through recess of the mobile element, that is to say a maximum flow rate,
  • a completely closed position in which no gas flow can pass through the through recess of the mobile element, that is to say zero flow, and
  • at least one intermediate position located between said total open position and total closed position, in which only part of the gas flow brought by the emergency line enters the through recess of the movable element, that is to say -say one or more reduced flow rates.
• the control means are configured to control the actuator means to effect an angular movement of the movable element between several intermediate positions, angularly offset from each other, each corresponding to a calibrated orifice opening level and/or to a given gas flow rate, that is to say reduced flow rates between the maximum flow rate and zero flow rate.
• the control means are configured to control the actuator means during normal operation of the device, that is to say prior to any malfunction, so as to regulate or adjust the preset emergency gas flow.
• the control means are configured to control the actuator means to effect an angular movement of the mobile element in a given position corresponding to the preset emergency flow.
• the control means are configured to determine a given calibrated orifice opening corresponding to the preset emergency flow rate.
• the control means are configured to determine the given calibrated orifice opening and/or the preset emergency flow rate from a correspondence table.
• it comprises electrical power supply means supplying electrical current to the components requiring electrical energy to operate, in particular the control means.
• the electrical power supply means comprises means of connection to the sector (110/220V) and/or a battery or the like.
• the flow control device of the NO emergency dosing system constitutes a system with a proportional calibrated orifice making it possible to regulate or adjust the preset emergency gas flow, prior to any malfunction of the device preventing any cooperation between the control means and the emergency solenoid valve, the flow control device, the valve device and/or the flow measuring device.
• the emergency gas flow from corresponds to the last flow measurement carried out by the flow measuring device having been carried out before the malfunction.

• au moins une source de NO contenant un mélange gazeux NO/N₂,
• un dispositif de délivrance de NO selon l'invention, alimenté en mélange gazeux NO/N₂par ladite au moins une source de NO,
• une branche inspiratoire d’un circuit patient alimentée en mélange gazeux NO/N₂par le dispositif de délivrance de NO, et
• un ventilateur médical, i.e. un appareil d’assistance respiratoire, en communication fluidique avec la branche inspiratoire pour alimenter ladite branche inspiratoire en un gaz respiratoire contenant au moins 21% d’oxygène.

The invention also relates to an installation for supplying gas to a patient comprising:

• at least one NO source containing a NO/N ₂ gas mixture,
• a NO delivery device according to the invention, supplied with a NO/N ₂ gas mixture by said at least one NO source,
• an inspiratory branch of a patient circuit supplied with a NO/N ₂ gas mixture by the NO delivery device, and
• a medical ventilator, ie a respiratory assistance device, in fluid communication with the inspiratory branch to supply said inspiratory branch with a respiratory gas containing at least 21% oxygen.

• le ventilateur médical délivre de l’air ou un mélange oxygène/azote.
• le ventilateur médical comprend une soufflante motorisée (i.e. turbine, compresseur ou analogue) délivrant le gaz respiratoire, typiquement de l’air ou un mélange oxygène/azote.
• le ventilateur médical comprend une soufflante motorisée commandée par des moyens de commande, telle une carte de commande électronique.
• le ventilateur médical est de type HFO.
• la source de NO contient un mélange gazeux NO/N₂contenant entre 100 et 2000 ppmv de NO, le reste étant de l’azote (N₂), conditionné à une pression comprise entre 10 et 250 bar abs, typiquement à plus de 100 bar abs (avant début de soutirage).
• la source de NO contient un mélange gazeux NO/N₂contenant entre 100 et 1000 ppmv de NO, le reste étant de l’azote (N₂), conditionné à une pression comprise entre 10 et 250 bar abs, typiquement à plus de 100 bar abs (avant début de soutirage).
• la source de NO est une (ou des) bouteille de gaz sous pression.
• la source de NO est une (ou des) bouteille de gaz ayant une contenance comprise entre 0,5 et 50 L (équivalent en eau).
• la bouteille de gaz comprend un corps cylindrique en acier ou en alliage d’aluminium.
• la bouteille de gaz est équipée d’un robinet simple (sans détendeur) ou à détendeur intégré ou RDI.
• la bouteille de gaz est équipée d’un RDI protégé par un capotage de protection, par exemple en métal ou polymère.
• le circuit patient comprend une branche inspiratoire et une branche expiratoire.
• le circuit patient comprend des conduites flexibles formant la branche inspiratoire et la branche expiratoire, typiquement des tuyaux en polymère.
• la branche inspiratoire et la branche expiratoire, e.g. des conduites flexibles, sont raccordées à une pièce de jonction, telle une pièce en Y.
• la branche inspiratoire et/ou la branche expiratoire sont reliées fluidiquement à une interface respiratoire patient, de préférence via la pièce de jonction.
• l'interface respiratoire patient comprend une sonde d’intubation trachéale ou masque respiratoire.
• la branche inspiratoire et la branche expiratoire comprennent des conduites flexibles, par exemple en polymère.
• la branche inspiratoire et la branche expiratoire sont en outre fluidiquement raccordées à, respectivement, des orifices de sortie et d’entrée du ventilateur médical.
• la branche inspiratoire du circuit patient peut comprendre un humidificateur de gaz.
• l’humidificateur de gaz est agencé en aval du module d’injection de NO de manière à pouvoir humidifier le gaz avant son administration par inhalation au patient.

Depending on the embodiment considered, the gas supply installation of the invention may comprise one or more of the following characteristics:

• the medical ventilator delivers air or an oxygen/nitrogen mixture.
• the medical ventilator comprises a motorized blower (ie turbine, compressor or the like) delivering the respiratory gas, typically air or an oxygen/nitrogen mixture.
• the medical ventilator comprises a motorized blower controlled by control means, such as an electronic control card.
• the medical ventilator is of the HFO type.
• the NO source contains a NO/N ₂ gas mixture containing between 100 and 2000 ppmv of NO, the remainder being nitrogen (N ₂ ), conditioned at a pressure of between 10 and 250 bar abs, typically at more than 100 bar abs (before start of withdrawal).
• the NO source contains a NO/N ₂ gas mixture containing between 100 and 1000 ppmv of NO, the remainder being nitrogen (N ₂ ), conditioned at a pressure of between 10 and 250 bar abs, typically at more than 100 bar abs (before start of withdrawal).
• the source of NO is one (or more) pressurized gas cylinders.
• the NO source is one (or more) gas cylinders with a capacity between 0.5 and 50 L (water equivalent).
• the gas cylinder comprises a cylindrical body made of steel or aluminum alloy.
• the gas bottle is equipped with a simple tap (without regulator) or with an integrated regulator or RDI.
• the gas cylinder is equipped with an RDI protected by a protective covering, for example made of metal or polymer.
• the patient circuit includes an inspiratory branch and an expiratory branch.
• the patient circuit comprises flexible pipes forming the inspiratory branch and the expiratory branch, typically polymer pipes.
• the inspiratory branch and the expiratory branch, eg flexible pipes, are connected to a junction part, such as a Y-shaped part.
• the inspiratory branch and/or the expiratory branch are fluidly connected to a patient respiratory interface, preferably via the junction part.
• the patient respiratory interface includes a tracheal intubation tube or respiratory mask.
• the inspiratory branch and the expiratory branch comprise flexible pipes, for example made of polymer.
• the inspiratory branch and the expiratory branch are further fluidly connected to, respectively, outlet and inlet ports of the medical ventilator.
• the inspiratory branch of the patient circuit may include a gas humidifier.
• the gas humidifier is arranged downstream of the NO injection module so as to be able to humidify the gas before its administration by inhalation to the patient.

• schématise une installation de délivrance de gaz équipée d’un système de dosage d’urgence de NO selon la présente invention ;
• schématise l’association entre orifice calibré et actionneur du système de dosage d’urgence de NO de ; et
• à schématisent le fonctionnement de l’association orifice calibré/actionneur de .

The invention will now be better understood thanks to the following detailed description, given by way of illustration but not limitation, with reference to the appended figures among which:

• schematizes a gas delivery installation equipped with an emergency NO dosing system according to the present invention;
• schematizes the association between calibrated orifice and actuator of the emergency NO dosing system of ; And
• has schematize the operation of the calibrated orifice/actuator association .

schematizes an embodiment of a gas delivery installation 1, 2 according to the present invention comprising a NO delivery device 1 comprising an emergency NO dosing mechanism, associated with a mechanical fan 2, i.e. that is to say a respiratory device delivering a respiratory gas, making it possible to deliver NO in gaseous form to a patient at a desired concentration corresponding to a dosage set by a physician-anesthetist or the like, typically between 1 and 80 ppmv of NO (ie ppm in volume).

The medical ventilator 2 delivers a respiratory gas containing at least 21% oxygen, such as air or a NO/N mixture ₂ , into a patient circuit 3, in particular into an inspiratory branch 31 of said patient circuit 3, serving to convey and supply the respiratory gas to a patient P during his inspiratory phases, that is to say to provide respiratory assistance to the patient P, and to convey the gases exhaled by the patient during his expiratory phases.

The medical ventilator 2 is a conventional device comprising for example a motorized blower, also called a turbine or compressor, delivering the respiratory gas into the patient circuit 3 and whose operation is controlled by one (or more) electronic control card or the like. It is electrically powered by power supply means, such as the mains (110/220V) and/or an internal battery.

As visible on , the patient circuit 3 here comprises an inspiratory branch 31 and an expiratory branch 32 fluidly connected to a part Y 33 or similar, in fluidic communication with a respiratory interface 30 making it possible to deliver the gas to the patient P or to collect the gases exhaled by said patient P. The respiratory interface 30 can for example be a facial mask or an intubation probe.

The inspiratory 31 and expiratory 32 branches comprise conduits, pipes, pipes, passages, tubing or the like, for example flexible polymer pipes, suitable for and configured to convey the gas flows.

The respiratory gas circulating in the inspiratory branch 31 of the patient circuit 3, that is to say going from the mechanical ventilator 2 to the patient P, is inhaled by the patient P while the gases exhaled by said patient P, ie enriched gases in CO ₂ , take the expiratory branch 32 of the patient circuit 3 towards the mechanical ventilator 2 to be discharged to the atmosphere by the mechanical ventilator 2.

Furthermore, a flow sensor 100 as well as an NO injection module 110 are arranged in the inspiratory branch 31 of the patient circuit 3. The flow sensor 100 is preferably arranged in the inspiratory branch 31 between the injection module of NO 110 and the mechanical fan 2.

The inspiratory branch 31 may also include a humidifier (not shown) in order to humidify the gas delivered to the patient P. Preferably, the humidifier is placed downstream of the NO injection module 110, that is to say between said NO injection module 110 and the respiratory interface 30 supplying the gas to the patient P.

The flow sensor 100 is used to measure the gas flow, i.e. a flow rate, delivered by the mechanical ventilator 2 and circulating in the inspiratory branch 31, for example a mass flow sensor or differential pressure measurement.

In the embodiment of , the flow sensor 100 is of the differential pressure measurement type, that is to say that the flow sensor 100 includes an internal restriction 101 which creates a pressure loss generating a differential or pressure gradient when a flow gas passes through this internal restriction 101.

As we see in , the flow sensor 100 comprises upstream 120 and downstream 121 chambers which are separated by a wall 122 crossed by a gas passage so as to form the internal restriction 101. An upstream line 103 and a downstream line 102 for measuring pressure are connected fluidly to the flow sensor 100 at connection sites located upstream and downstream of the internal restriction 101, in particular to the upstream 120 and downstream 121 chambers in order to carry out pressure measurements of the circulating flow, before and after loss of charge.

The pressure difference created by the internal restriction 101 is determined by a differential pressure sensor 104 connected to the flow sensor 100 via the upstream 102 and downstream 103 lines which form pressure measurement conduits and supply the differential pressure sensor 104, pressure measurements of the circulating flow, before and after loss of pressure. Preferably, the differential pressure sensor 104 is integrated into the housing 10 of the NO 1 delivery device. The sensor 104 can either be electrically connected to a control unit 130, also called control means 130, or can transmit the measurements to it. pressure so that they are processed electronically.

The control unit 130, i.e. the control means 130, comprises a data processing system, i.e. measurements, comprising for example one (or more) microprocessor(s) arranged on one (or more) electronic card and implementing implements one (or more) algorithms, i.e. one (or more) computer programs.

In other words, the control unit 130 is configured to process and/or exploit the pressure measurement signals or the pressure values transmitted by the differential pressure sensor 104 cooperating with the flow sensor 100.

Of course, the control unit 130 can also be configured to control other electromechanical elements integrated in the housing 10 or external carcass of the NO delivery device 1.

For example, the control unit 130 has a pre-recorded correspondence table which allows the determination of the flow rate of gas circulating in the inspiratory branch 31 and the flow sensor 100, that is to say to transform a value of pressure transmitted by the differential pressure sensor 104 in value of flow passing through the flow sensor 100. Such determination of the flow passing through the flow sensor 100 then makes it possible to calculate the quantity of NO to be added to the gas circulating in the inspiratory branch 31 before reaching patient P.

In other words, by using the pressure measurement returned by the differential pressure sensor 104 and the correspondence table, the control unit 130 can determine the gas flow rate coming from the mechanical fan 2 and the quantity of NO which must be added, via the NO injection module 110, in order to obtain the desired NO concentration, i.e. the dosage defined by the doctor, to be inhaled by the patient P.

The gas mixture obtained at the NO 110 injection module then mainly comprises nitrogen (N ₂ ), oxygen (O ₂ ) in a content of at least 21% vol., and NO at a content typically between 1 and 80 ppmv.

More precisely, depending on the gas flow (ie air or N ₂ /O ₂ ) circulating in the inspiratory branch 31 having been determined using the flow sensor 100, the control unit 130 determines the quantity of NO, typically a mixture of NO and N ₂ , to be added to the gas circulating in the inspiratory branch 31 by the NO injection module 110, in order to obtain the desired concentration.

The NO 1 delivery device is supplied with gaseous NO, typically a gaseous NO/N ₂ mixture, coming from a source of NO 250 fluidly connected to the NO 1 delivery device, in particular to a high pressure line 116 of said device for delivering NO 1, via a supply line 251, such as a flexible conduit or the like.

Typically, the source of NO 250 is one (or more) pressurized gas cylinders containing a mixture of NO/N₂containing a concentration of NO generally between 100 and 2000 ppmv, preferably between 200 and 1000 ppmv, for example of the order of 800 ppmv, and conditioned at a pressure (when completely full) which can reach 200 to 250 bar abs, or even more.

The NO/N ₂ mixture is supplied to the injection module 110 by the NO 1 delivery device via an injection line 111, such as a flexible gas pipe.

The injection line 111 is fluidly connected to a high pressure line 116 of the NO 1 delivery device, which high pressure line 116 has a high pressure inlet fluidly connected to the NO source to be supplied with NO/N ₂ under pressure , that is to say at a pressure of up to 200 bar abs.

The high pressure line 116, for example a gas passage or conduit, is arranged in the housing 10 of the NO 1 delivery device and includes a pressure regulator 115 which reduces the pressure of the NO/N ₂ mixture to a stable value, for example 4 bar abs. The outlet port of the pressure regulator 115 provides a stable pressure in the upstream portion of the injection line 111.

A valve device 113, such as a solenoid valve, for example a proportional solenoid valve, such as the miniature VSO series from Parker for example, is arranged in the device 1 in order to control the flow of gaseous NO within the injection line 111 The gas flow circulating in the injection line 111 is measured by a flow measuring device 112, also called NO flow sensor, arranged on the injection line 111, preferably placed downstream of the solenoid valve 113, as visible on .

The pressure regulator 115, the valve device or solenoid valve 113, the NO flow sensor 112 and a portion of the injection line 111 are arranged in the housing 10 of the NO delivery device 1.

The valve device 113 is configured to be normally in a closed position (i.e. a closed state) to prevent any circulation of gas in the injection line 111. To move to the open position, the valve device 113 must be controlled by the control means 130.

Furthermore, there is provided an emergency NO dosing system 200 arranged in the housing 10 of the NO delivery device 1.

The NO emergency dosing system 200 includes an emergency line 201, also called a bypass line, such as a gas passage, a gas conduit or the like. The emergency line 201 connects fluidly to the injection line 111 at a first connection site 111a located upstream of the valve device 113, such as a proportional solenoid valve, and here downstream of the pressure regulator 115, and in a second connection site 111b located downstream of the valve device 113 and, preferably, downstream of the NO flow sensor 112.

In other words, a valve device 113, such as a proportional solenoid valve, and preferably the NO flow sensor 112 are located between the first and second connection sites 111a, 111b of the emergency line 201, that is to say that the emergency line 201 bypasses, the valve device 113 and preferably the NO flow sensor 112 located on the injection line 111. According to another embodiment, the second connection site 111b could be located downstream of the valve device 113 and upstream of the NO flow sensor 112, that is to say between these two elements.

The emergency line 201 comprises an emergency solenoid valve 202 and a flow control device 210 forming part of the emergency dosing system 200 of the invention. This emergency solenoid valve 202 is configured to be normally in an open position (i.e. open state) to allow gas circulation in the emergency line 201.

The flow control device 210 actually forms a calibrated orifice system 204 of the proportional type. It can take different forms, ie arrangements, in particular that illustrated on has and detailed below.

The emergency solenoid valve 202 is preferably an “all or nothing” type solenoid valve having two possible states, namely an open state and a closed state, for example a solenoid valve from the Picosol series from IMI Norgren. The emergency solenoid valve 202 is normally open, that is to say that in the absence of an electrical command coming from the control unit 130, the emergency solenoid valve 202 is in the open state, i.e. position open, which then allows the gas from the NO source to take the emergency line 201 from the first connection site 111a towards the second connection site 111b.

These are the control means or control unit 130, which ensure the closing of the emergency solenoid valve 202, that is to say its passage from the open state to the closed state, i.e. in the closed position.

In other words, the control means 130, i.e. the control unit, are configured to cooperate with the emergency solenoid valve 202, the flow control device 210, the valve device 113 and the flow measurement device 112, during normal operation of device 1.

In the embodiment presented on has , the flow control device 210 forming a proportional calibrated orifice system, that is to say constituting, comprising or forming a calibrated orifice 204 of proportional type, comprises an actuator means 203 cooperating with a movable element 2042 arranged in a compartment 2041, said movable element 2042 comprising a through recess 2043. However, the flow control device 210 constituting the calibrated orifice 204 of proportional type can take another form, for example a needle valve type device or even a assembly comprising a pressure regulator arranged upstream of a fixed orifice, said pressure regulator being able to be adjusted to different outlet pressures, thus generating different flow rates passing through said fixed orifice.

So, is a sectional diagram of an embodiment of the flow control device 210, ie of the calibrated orifice 204, which is formed here by the actuator means 203 and the movable element 2041 associated with the through recess 2043, of the emergency NO dosing system equipping the NO delivery device 1 of the invention.

The actuator means 203, more simply called actuator, of is preferably a stepper type motor 2030, for example like that marketed by the company Portescap, extended by an axis 2031 mechanically coupled in 2031a to the mobile element 2042.

Furthermore, the mobile element 2042 is here a sphere. The sphere forming the movable element 2042 can be metallic, for example stainless steel and has a through recess 2043, that is to say it is diametrically crossed by a drilling or internal passage allowing the passage of gas. The mobile element 2042, i.e. the sphere, is housed in a compartment or internal housing 2041 forming a sphere chamber which is here of generally spherical shape. Housing 2041 is arranged in a part forming body 2040. The external diameter of sphere 2042 is substantially equal to the internal diameter of internal housing 2041.

The body part 2040 can also be metallic, for example a steel ball or the like. It includes an input port 201a and an output port 201b in fluid communication with the internal housing 2041.

On , we see that the through recess 2043 of the sphere 2042 is aligned with the inlet ports 201a and outlet 201b of the body 2040, which are in fluidic communication with the emergency line 201, that is to say that They are in fluid continuity, so that the gas can flow from the inlet port 201a to the outlet port 201b via the through recess 2043 of the sphere 2042.

As indicated, the actuator means 203 is here a stepper motor 2030 rotating the axis 2031 and therefore the sphere 2042. In response to a command coming from the control unit 130, the stepper motor 2030 will adopt a different position and rotate the axis 2031 which will then cause the sphere 2042 to also rotate.

Considering that the control unit 130 is capable of varying the control value proportionally, it follows that the axis 2031 can undergo more or less significant rotational movements and in a proportional manner, for example between 0 and 90°. In other words, the rotational movement undergone by the axis 2031 is therefore transmitted to the sphere 2042 which pivots in response, within its housing 2041, as illustrated in has , which makes it possible to set or adjust the desired gas flow, during normal operation of the device 1.

So, is a top diagram of the calibrated orifice 204 of showing, as already explained, the axis 2031 which requires the sphere 2042 to present its recess 2043 in continuity with the input ports 201a and output 201b of the body 2040 so as to create a fluid connection between said input ports 201a , 201b and thus authorize the passage of gas through the ports 201a, 201b and the recess 2043. The calibrated orifice 204 is then at its maximum opening, that is to say in the fully open position. In this position, the axis AA of the through recess 2043 of the sphere 2042 is (quasi) coaxial with the axis BB passing through the inlet (201a) and outlet (201b) ports so that the opening is maximum, therefore the maximum flow in the emergency line 201, including through the through recess 2043 of the sphere 2042.

In , the control unit 130 controlled the stepper motor 2030 to cause the axis 2031 to undergo a rotation here of the order of 90° and consequently also the sphere 2042 which also undergoes the same rotation of 90 °. After rotation, the inlet ports 201a and outlet 201b of the body 2040 of the calibrated orifice 204 no longer face the recess 2043 of the sphere 2042 but a non-hollowed out portion 2044, i.e. full, of the sphere 2042 and then find themselves completely blocked by the non-hollowed part 2044 of the sphere 2042. The fluid connection is then broken and no gas can circulate between the inlet ports 201a and outlet 201b of the body 2040 of the calibrated orifice 204. The calibrated orifice 204 is then completely closed.

In this so-called closed position, the axis AA of the through recess 2043 of the sphere 2042 is (quasi) perpendicular to the axis BB passing through the inlet (201a) and outlet (201b) ports so that no gas passage takes place through the through recess 2043, therefore in the emergency line 201.

Between And , the control unit 130 imposed extreme control values on the actuator 203, ie between 0° and 90° of rotation, making it possible to obtain either complete communication (cf. ), or complete insulation (cf. ) of the inlet 201a and outlet 201b ports of the body 2040 of the calibrated orifice 204.

However, the control unit 130 is also configured to be able to assign, proportionally, commands causing a rotation of the axis 2031 and the sphere 2042 between these two extreme angular positions, i.e. 0° and 90° of rotation, that is to say an angle not zero but less than 90°.

So, gives the example of an intermediate angular position where the sphere 2042 has undergone a rotational movement of around 45°. In this case, the inlet port 201a of the body 2040 of the calibrated orifice 204 is partially obstructed, that is to say exposed to non-recessed parts 2044 and recessed parts 2043 of the sphere 2042. The passage section gas of the recessed part 2043 of the sphere 2042 in fluidic relation with the inlet port 201a is then defined by a level (or size) of opening O. This gas passage section is always less than the maximum section of fluid connection as shown in . By means of axial rotation, the same opening level O appears between the outlet port 201b and the recessed part 2043 of the sphere 2042 of the body 2040 of the calibrated orifice 204.

In the so-called intermediate positions, the axis AA of the through recess 2043 of the sphere 2042 and the axis BB passing through the inlet (201a) and outlet (201b) ports form between them a variable angle understood strictly here between 0 and 90° so that the passage of gas through the through recess 2043, therefore in the emergency line 201, is limited/reduced but not zero, nor maximum, that is to say depending on of the desired opening O of the calibrated orifice 204.

Thus, depending on the command imposed on the actuator 203 by the control unit 130, the opening level O defined by the intersection of the input ports 201a, output ports 201b and the recessed part 2043 of the sphere 2042, varies by a zero value ( ) to a maximum value ( ), that is to say it can take the intermediate values located between these two extreme values, ie between 0 and 90°, which makes it possible to regulate or adjust the flow rate of gas circulating in the emergency line 201.

Indeed, it is easy to understand that each level or opening value O corresponds to an equivalent calibrated orifice whose gas passage diameter is a function of the positioning of the sphere 2042 and therefore of the command sent by the control unit 130 , i.e. the control means, to the actuator 203.

As already said, this assembly therefore forms a proportional calibrated orifice since its caliber or opening level O varies as a function of the angular position taken by the sphere 2042 within the body 2040 of the calibrated orifice 204.

However, the pressure prevailing in the upstream portion of the emergency line 201, that is to say upstream of the calibrated orifice 204, is stable and known since it corresponds to the expansion pressure of the pressure regulator 115 fixed for example at 4 bar abs. The gas flow rate circulating in the downstream portion of the emergency line 201, that is to say downstream of the calibrated orifice 204, is therefore a function of the opening level O.

Thus, the control unit 130 can have a correspondence table linking a given control level to an opening level and to a gas flow rate passing through the calibrated orifice 201 towards the injection line 111 and y penetrating at the second connection site 111b.

For reasons of simplification, it is admitted that the pressure level prevailing in the inspiratory branch 31 of the patient circuit 3, and therefore in the NO injection module 110 and the injection line 111 is negligible with regard to the pressure of relaxation of the pressure regulator 115 and therefore has no impact on the precision of the flow measurements circulating in the emergency line 201 carried out by the control unit 130.

Of course, according to a particular embodiment, additional measuring means, such as an additional pressure measuring device arranged to carry out a pressure measurement downstream of the calibrated orifice 204 of the emergency line 201 can be implemented , i.e. used, for compensation purposes, without changing in any way the object of the present invention.

Finally, it should be noted that the choice of a stepper motor is particularly recommended because, unlike the solenoid valves 202, 113 which will take a rest position, in the event of a power cut, namely an open position for the on-off solenoid valve 202 and a closed position for the proportional solenoid valve 113, the position of the stepper motor remains permanent and fixed according to the last command imposed. In other words, the calibrated orifice 204 has a fixed opening level corresponding to the last command value received by the stepper motor, i.e. the last command coming from the control means 130.

Of course, the present invention is not limited to a stepper motor type actuator. Indeed, any other actuator maintaining its position in the event of a power supply failure and which can be coupled to a mechanical mechanism making it possible to define a calibrated orifice of variable size can be used, such as for example a linear motor or other.

Furthermore, the NO 1 delivery device is electrically powered by a power supply, such as the sector (110/220V) or an internal battery, in order to allow the proper functioning of its components requiring electric current to operate, in particular the actuator 203, such as a step-by-step electric motor, the control unit 130, the solenoid valves 202, 113, or others.

In addition, the NO 1 delivery device also includes storage means, such as a computer memory, for storing data, information or others, for example one or more correspondence tables, the gas flow measurements carried out by the device flow measurement 112, or others.

In the event of a major failure in the operation of the NO 1 delivery device, caused for example by a break in its power cable caused by vibrations during patient transport for example or in the event of a power supply fault electric, we must be able to continue to treat the patient with inhaled NO, despite the malfunction causing a stoppage of operation of the control means 130.

To this end, the device 1 of the invention is configured so that in the event of such a failure, the emergency solenoid valve 202 switches to the open position to allow gas circulation in the emergency line 201, while, at the same time, the valve device 113 switches to the closed position to stop any circulation of gas in the injection line 111, which makes it possible to provide, via the emergency line 201 and the flow control device 210, the gas at a preset emergency gas flow.

In fact, during the normal operation of the device 1 preceding the malfunction, according to the invention, said emergency gas flow is determined by the control means 130 from one or more gas flow measurements provided by the measuring device flow rate 112, to the control means 130. The control means 130 can then preset the flow control device 210 so that it can deliver the gas at the preset emergency gas flow rate.

In other words, the control means 130 determine the emergency gas flow to be administered in the event of a breakdown or other malfunction, from the gas flow measurements provided by the flow measuring device 112 during normal operation of the device 1, and act on the flow control device 210 to adjust this prefixed emergency gas flow, for example by adjusting the caliber or opening level O acting on the angular position taken by the sphere 2042 within the body 2040 of the calibrated orifice 204, as explained above.

More precisely, the operation of the NO emergency dosing system 200 of the NO delivery device 1 of the invention is generally as follows.

As illustrated in , the NO 1 delivery device cooperates with a mechanical ventilator 2 in order to provide therapeutic aid to the patient P. As already explained, the gas flow (ie air or N ₂ /O ₂ ) coming from the mechanical ventilator 2 and circulating in the inspiratory branch 31 of the patient circuit 3 is continuously measured by the flow sensor 100 and the control unit 130. This flow measurement allows the control unit 130 to determine, in real time, the NO flow to be injected into the injection line 111 and the NO injection module 110 in order to satisfy the desired NO concentration in the gas supplied to the patient, namely typically between 5 and 80 ppmv.

In normal operation, in order not to introduce additional flow coming from the emergency line 201 into the injection line 111, the control unit 130 controls the solenoid valve 202, which is preferably of the all or nothing type, in position closed and, in parallel, will control the actuator 203, i.e. stepper motor, in order to preset the calibrated orifice 204 by defining a given opening level O.

This is carried out in the following manner by the control unit 130, from one or more flow measurements coming from the flow measurement device 112, as already explained.

The control unit 130 first averages the flow rate of NO (ie the NO/N ₂ mixture) having circulated in the injection line 111 for a given time, for example for 1 minute (or over a period of longer time but the flow rate must then be converted into L/min), during normal operation of the device 1. The control unit 130 therefore evaluates a fixed average NO flow rate value (in L/min) making it possible to approximate of the desired NO concentration.

When this value has been determined, the control unit 130 carries out a conversion via its stored correspondence table so as to control the actuator 203 of the flow control device 210 and consequently define an opening level of the calibrated orifice 204 in order to authorize a flow rate of NO circulating in the emergency line equal to the calculated value of fixed average NO. It is this calculated value of average NO which will serve as emergency gas flow in the event of a malfunction of device 1.

It should be noted that this activity has no physical effect, i.e. no gas flow circulates in the emergency line 201 because the on-off solenoid valve 202 is closed.

Therefore, in the event of a major failure of the NO 1 delivery device and/or interruption of its electrical supply, with the exception of the actuator 203 and the pressure regulator 115 which has a purely pneumatic operation, the all of the electromechanical actuators, in particular the solenoid valves, return to their rest position and the control unit 130, as well as the various sensors, find themselves without electrical power, therefore without the ability to communicate and/or pilot/command others components.

As already indicated, the proportional solenoid valve 113 returns to its rest position, namely its closed position preventing any passage of gas, while the solenoid valve 202 simultaneously finds itself in its rest position, namely its open position, authorizing the passage gas coming from the NO source in the emergency line 201 and its circulation until reaching the second junction site 111b, then the downstream part of the injection line 111.

The NO/N ₂ mixture therefore circulates in the emergency line 201 at the prefixed emergency flow rate which is controlled by the calibrated orifice, namely the last valid value of the fixed average NO flow rate having been determined by the control unit 130 during normal operation of device 1, prior to its malfunction.

The emergency flow of NO/N ₂ which joins the injection line 111 (at 111b) can then be injected into the inspiratory branch 31 of the patient circuit 3 via the NO injection module 110, as already explained.

In other words, according to the invention, the flow control device 210 is configured to supply the gas, ie NO/N ₂ , at a prefixed emergency gas flow rate, where said emergency gas flow rate is determined by the control means 130 from one (or more) gas flow measurements provided by the flow measuring device 112, during normal operation of the device 1 preceding the malfunction, for example the last flow value having been measured before the malfunction affecting the proper operation of the device 1.

This flow value is preset within the flow control device 210, for example by acting on the angular position taken by the sphere 2042 within the body 2040 of the calibrated orifice 204 of the flow control device 210 in order to y vary the caliber or opening level O, as explained above, by controlling said flow control device 210 by the control means 130, said presetting taking place, that is to say being operated or carried out , during said normal operation of device 1.

Of course, the fact of injecting a continuous flow of NO into the inspiratory branch 31 of the patient circuit 3 does not guarantee the same precision of concentration of inhaled NO as when the NO delivery system 1 operates in normal operation, this is that is to say by adjusting the NO flow rate as a function of the flow rate passing through the flow sensor 100, but the buffer volume generated by the portion of the inspiratory branch 31 located downstream of the NO injection module, which is possibly increased by volume of the humidification chamber when present, makes it possible to smooth out variations in the concentration of NO inhaled by the patient and to get closer to the desired target value, that is to say the NO dosage.

In all cases, being able to approach the desired NO target value thanks to the NO emergency dosing system 200 integrated into the NO delivery device 1 of the invention considerably improves safety for the patient in comparison with a flow rate. of fixed emergency NO (for example 250 mL/min) usually delivered by the safety system of NO delivery devices of the prior art.

• pour un débit moyen de NO nécessaire de 0.05 L/min pour assurer normalement une concentration en NO de 10 ppmv (cas d’utilisation en néonatologie avec ventilateur de type HFO), la concentration résultante avec le débit fixe de 250 mL/min, est de 50 ppmv, ce qui correspond à une multiplication par 5 de la posologie souhaitée.
• à l’inverse, pour un débit moyen nécessaire de NO de 1 L/min pour assurer 80 ppmv de concentration en NO (cas d’utilisation chez l’adulte, par exemple en cas d‘hypertension pulmonaire pendant une chirurgie cardiaque), la concentration résultante chute à 20 ppmv, ce qui correspond à une diminution de 75% de la posologie souhaitée.

Thus, for comparison, while the emergency NO dosing system 200 integrated into the NO delivery device 1 of the invention makes it possible to guarantee a NO concentration substantially equal to the desired dosage, with an emergency system based on a fixed flow rate of 250 mL/min, as conventionally implemented in NO delivery devices of the prior art:

• for an average NO flow rate required of 0.05 L/min to normally ensure an NO concentration of 10 ppmv (case of use in neonatology with HFO type ventilator), the resulting concentration with the fixed flow rate of 250 mL/min is of 50 ppmv, which corresponds to a 5-fold increase in the desired dosage.
• conversely, for a necessary average NO flow rate of 1 L/min to ensure 80 ppmv NO concentration (case of use in adults, for example in the case of pulmonary hypertension during cardiac surgery), the resulting concentration drops to 20 ppmv, which corresponds to a 75% reduction in the desired dosage.

In both cases, significant dosage deviations can lead to unacceptable and dangerous situations for the patient, unlike the emergency NO dosing system 200 integrated into the NO delivery device 1 of the invention which allows it to respect the desired dosage.

• injectant de façon automatique un débit de secours de NO sans attendre que l’utilisateur ne se rende compte de la situation et intervienne en basculant sur le dosage pneumatique de secours.
• garantissant que la concentration de NO inhalé par le patient est similaire à la concentration souhaitée par le médecin, c'est-à-dire la posologie désirée.

In other words, the NO emergency dosing system 200 of the invention has undeniable advantages by reinforcing patient safety by:

• automatically injecting an emergency flow of NO without waiting for the user to realize the situation and intervene by switching to emergency pneumatic dosing.
• guaranteeing that the concentration of NO inhaled by the patient is similar to the concentration desired by the doctor, i.e. the desired dosage.

Of course, the switch to the emergency NO dosing system 200 of the invention is only temporary, that is to say it only lasts the time necessary to replace the faulty equipment or component which triggered the audible and/or visual alarm system in order to alert the nursing staff.

In order to avoid improper activation of the NO emergency dosing system 200, the control unit 130 is also configured to carry out appropriate initialization and shutdown sequences. For example, in the event of a shutdown desired by the user of the NO therapy, the control unit 130 can control the actuator 203 in order to close the calibrated orifice 204. Thus, in the event of voluntary extinction and therefore opening of the solenoid valve 202, the “closed” configuration of the calibrated orifice 204 then prohibits any circulation of NO flow in the emergency line 201, until the NO delivery device 1 is stopped .

The NO 1 delivery device equipped with the NO emergency dosing system 200 of the invention is particularly well suited to the supply of a gas mixture comprising 1 to 80 ppmv of NO and at least 21% vol. of oxygen to patients (adults, children, adolescents or newborns), suffering from pulmonary hypertension and/or hypoxia, which can cause pulmonary or similar vasoconstrictions, for example caused by pulmonary pathologies or disorders of the type PPHN (persistent pulmonary hypertension of the newborn) or ARDS (acute respiratory distress syndrome), or even caused by cardiac surgery with the patient placed on extracorporeal blood circulation.

Claims (10)

NO delivery device (1) for supplying a gas containing NO comprising:

• a NO injection line (111) for conveying the gas containing NO,
• a valve device (113) arranged on the injection line (111) for controlling the circulation of gas containing NO in the injection line (111), said valve device (113) being configured to be normally in a closed position to prevent any circulation of gas in the injection line (111),
• a flow measurement device (112) arranged on the injection line (111) to carry out one or more flow measurements of the gas containing NO circulating in the injection line (111),
• an emergency line (201) fluidly connecting to the injection line (111) upstream and downstream of the valve device (113), said emergency line (201) comprising an emergency solenoid valve (202) configured to normally be in an open position to allow gas circulation in the emergency line (201), and a flow control device (210), and
• control means (130) configured to cooperate with the emergency solenoid valve (202), the flow control device (210), the valve device (113) and the flow measurement device (112),

and in which, in the event of a malfunction leading to a cessation of all cooperation with the control means (130):

• the emergency solenoid valve (202) is configured to move to the open position to allow gas circulation in the emergency line (201),
• the valve device (113) is configured to go into the closed position to stop any circulation of gas in the injection line (111), and
• the flow control device (210) is configured to supply the gas at a preset emergency gas flow, where said emergency gas flow:
  • is determined by the control means (130) from at least one gas flow measurement provided by the flow measurement device (112), during normal operation of the device (1) preceding said malfunction, and
  • is preset by controlling said flow control device (210) by the control means (130), during said normal operation of the device (1).

Device according to claim 1, characterized in that the control means (130) are further configured to, during normal operation of the device (1):

1. control the emergency solenoid valve (202) so that it is in a closed position preventing any circulation of gas in the emergency line (201),
2. control the valve device (113) to authorize gas circulation in the injection line (111) and at least one gas flow measurement by the flow measurement device (112) and
3. controlling the flow control device (210) to preset the emergency gas flow from at least one gas flow measurement provided by the flow measurement device (112).

Device according to one of the preceding claims, characterized in that, during normal operation of the device (1), the flow measurement device (112) is configured to carry out several successive flow measurements. Device according to claim 3, characterized in that, during normal operation of the device (1), the control means (130) are further configured to determine the emergency gas flow from one or more flow measurements carried out by the flow measurement device (112). Device according to claim 1, characterized in that it comprises storage means for storing at least part of the successive flow measurements carried out by the flow measurement device (112). Device according to claim 4, characterized in that the emergency gas flow from corresponds to the last flow measurement carried out by the flow measuring device (112) having been carried out before the malfunction. Device according to claim 1, characterized in that the emergency solenoid valve (202) is of the all-or-nothing type. Device according to claim 1, characterized in that the control means (130) comprise at least one microprocessor. Installation for supplying gas (1, 2) to a patient comprising:

• at least one NO source (250) containing a NO/N ₂ gas mixture,
• a NO delivery device (1) according to one of the preceding claims, supplied with a NO/N ₂ gas mixture by said at least one NO source (250),
• an inspiratory branch (31) of a patient circuit (3) supplied with a NO/N ₂ gas mixture by the NO delivery device (1), and
• a medical ventilator (2) in fluid communication with the inspiratory branch (31) for supplying said inspiratory branch (31) with a respiratory gas containing at least 21% oxygen, preferably air or an oxygen/nitrogen mixture.

Installation according to claim 9, characterized in that the NO source (250) contains a NO/N ₂ gas mixture containing between 100 and 2000 ppmv of NO, the remainder being nitrogen (N ₂ ), conditioned at a pressure between 10 and 250 bar abs.