Gaseous NO administration system including a medical ventilator with integrated humidifier

Abstract

Title of the invention Installation for administering gaseous NO comprising a medical ventilator with integrated or associated humidifier The invention relates to an installation for administering gaseous NO (10) comprising a medical ventilator with integrated or associated humidifier (30), fluidically connected to an inspiratory branch (21) of a patient circuit (2) to deliver thereto a humidified gas flow containing oxygen, such as air or an O2 / N2 mixture, a flow sensor (70) arranged on the inspiratory branch (21), and an NO supply apparatus (1) fluidically connected to the inspiratory branch (21) downstream of the flow sensor (70) to inject thereto a flow of gas based on NO. The flow sensor (70) comprises at least one heating element (71), preferably of the resistive type. Abstract figure: Figure 3

Description

Title of the invention: Installation for administering gaseous NO comprising a medical ventilator with integrated humidifier

[0001] The invention relates to a gaseous NO administration installation comprising a medical ventilator with integrated humidifier fluidly connected to an inspiratory branch of a patient circuit including a flow sensor with a heating element, and an NO supply apparatus fluidly connected to the inspiratory branch downstream of the flow sensor to inject therein a flow of NO-based gas, typically an NO / N2 mixture, and thus obtain a final humidified mixture containing NO, oxygen, nitrogen and water vapor.

[0002] Inhaled nitric oxide or NOi is a gaseous drug commonly used to treat patients suffering from acute pulmonary arterial hypertension, in particular pulmonary vasoconstrictions in adults or children, including newborns or PPHN (in English for persistent pulmonary hypertension of the newborn), as described for example by EP-A-560928 or EP-A-1516639.

[0003] An installation for implementing a NOi treatment, commonly called a NO administration installation, conventionally comprises one or more NO / N2 mixture bottles supplying an NO supply device, a medical ventilator, i.e. a respiratory assistance device, for delivering an oxygen-based respiratory gas (>21% vol. approximately), such as an O2 / N2 mixture, air or oxygen, a patient circuit with an inspiratory branch supplied with the gas flows coming from the medical ventilator and the NO supply device, and a patient kit comprising in particular a respiratory interface, such as a tracheal tube or a respiratory mask, supplied by the inspiratory branch of the patient circuit with the gas mixture obtained, i.e. the final NO / O2 / N2 mixture.

[0004] Furthermore, a gas humidifier is generally arranged on the inspiratory branch typically downstream of the NO / N2 injection site from the NO supply device, which serves to slightly humidify the gas before administering it to the patient so as to avoid or minimize the risk of drying out the patient's respiratory tract due to the administration of a gas that is too dry.

[0005] Such a NO administration facility is used in a hospital setting to administer NOi treatment and thus treat patients who need to inhale NO to treat their pulmonary arterial hypertension. The dosage varies from patient to patient, in particular the NO dosage prescribed by the doctor but also other ventilatory parameters, such as the ventilation mode, the minute volume set to vent- medical device and duration of administration.

[0006] Therefore, in order to be able to regulate or adjust the NO concentration supplied to the patient, i.e. to observe the dosage set by the doctor or the like, it is usual to arrange a flow sensor on the inspiratory branch between the medical ventilator and the gas humidifier.

[0007] This flow sensor makes it possible to measure the flow rate of gas circulating in the inspiratory branch and to provide the flow rate measurements made to the control means of the NO supply device to which it is connected. These flow rate measurements are transmitted to the control means and processed by them to determine the quantity, i.e. flow rate, of NO / N2 mixture to be provided to obtain the final mixture at the desired NO concentration. This NO / N2 flow is injected into the inspiratory branch, between the flow rate sensor and the gas humidifier, where it mixes with the gas flow containing oxygen coming from the medical ventilator, e.g. air or NO / N2 mixture.

[0008] If such an installation works perfectly with a conventional ventilator and humidifier arranged on the inspiratory branch downstream of the flow sensor, it has been observed in practice that errors in flow measurement occur when the medical ventilator incorporates gas humidifying means, that is to say the gas humidifier is no longer arranged downstream of the flow sensor but upstream of it, that is to say within the medical ventilator itself or associated with it.

[0009] Indeed, with such a medical ventilator with a so-called "integrated" humidifier, the gas flow containing oxygen, such as air or an O2 / N2 mixture (>21% O2 approximately), is humidified before leaving the medical ventilator, and therefore contains a significant proportion of water (i.e. humidity) which will distort the measurements made by the flow sensor and therefore lead to determining an erroneous flow rate of the gas flow.

[0010] This results mainly from water condensation forming in the sensor, which disrupts the flow rate measurements transmitted to the control means of the NO supply device. This then results in erroneous calculations within the control means leading to incorrect dosing of the NO injected into the flow circulating in the inspiratory branch and untimely alarm triggering.

[0011] A problem is therefore to propose an installation for administering NO including a medical ventilator with integrated humidifier which is improved, in particular in which the flow measurement errors by the flow sensor are limited or minimized, despite the fact that the humidification of the gas takes place upstream of the flow sensor, within the medical ventilator.

[0012] One solution of the invention relates to an installation for administering gaseous NO to a patient, i.e. a person, comprising: - a medical ventilator with integrated or associated humidifier, fluidically connected to an inspiratory branch of a patient circuit to deliver a gas flow humidified containing oxygen, - a flow sensor arranged on the inspiratory branch, - and a NO supply device fluidically connected to the ins branch aspiration downstream of the flow sensor to inject a flow of NO-based gas,

[0013] characterized in that the flow sensor comprises at least one heating element.

[0014] Depending on the embodiment considered, the installation of the invention may comprise one or more of the following characteristics: - the medical ventilator delivers a humidified gas flow containing oxygen (at least 21% vol. approximately), such as air or an O2 / N2 mixture, or even oxygen. - the fan incorporates gas humidifying means, i.e. the gas humidifier. - the gas humidifier is arranged within the medical ventilator itself or associated with it so as to deliver a humidified gas (i.e. with water vapor) containing oxygen (i.e. > 21% vol. approximately), typically air or an O2 / N2 mixture, or even oxygen. - the NO supply device is supplied by one or more NO sources, in particular one or more pressurized gas cylinders containing a NO / N2 mixture. - the NO supply device delivers a gas stream containing NO and nitrogen (N2). - the flow sensor is configured to perform flow measurements within the inspiratory branch. - the flow sensor is connected to the control means of the NO supply device so as to provide them with flow measurements. - the patient circuit, typically the inspiratory branch, includes one or more gas conduits, such as one or more flexible conduits. - the patient circuit, typically the inspiratory branch, supplies a respiratory interface, such as a respiratory mask or a tracheal intubation tube. - the patient circuit further comprises an expiratory branch connecting the respiratory interface to the medical ventilator to return the gases exhaled by the patient, i.e. exhaled gases containing CO2. - the NO supply device includes control means. - the flow sensor is connected to the control means of the NO supply device and configured to provide them with flow measurements (i.e. signal or value). - the means of controlling the NO supply device are configured to process the flow measurements (i.e. signal or value) in order to determine the gas flow circulating in the inspiratory branch at the location where the flow measurements are made. the NO supply apparatus comprises control means for modifying the electrical power supplied to said at least one heating element in order to adjust the temperature of said at least one heating element. the control means are configured to modify the electrical power supplied to said at least one heating element in order to adjust the temperature of said at least one heating element as a function, for example, of the quantity of water vapor within the flow sensor. alternatively, the control means are configured to modify the electrical power supplied to said at least one heating element in order to adjust the temperature of said at least one heating element from a predefined power value, for example stored. the control means are configured to modify the electrical power supplied to said at least one heating element by delivering power information (eg value) corresponding to a power between 0 and 100%. it comprises heating activation means, for example a key, a button or other, allowing the user to control the activation (ie start) of the heating of the flow sensor. the NO supply apparatus comprises an internal gas circuit comprising flow control means, in particular valve means, typically one or more solenoid valves, in particular one or more on-off (ON) or proportional solenoid valves. the valve means, typically the solenoid valve(s), arranged on the internal gas circuit are controlled, i.e. commanded or piloted, by the control means of the NO supply device. the internal gas circuit of the NO supply device carries the mixture no / n2. the means for controlling the NO supply device comprise one or more microprocessors, in particular one or more microcontrollers. the means for controlling the NO supply device comprise at least one electronic card, preferably the electronic card comprises the microprocessor(s). the means for controlling the NO supply device further comprise storage means, in particular a computer memory, for example a flash memory or the like. the control means comprise at least one microprocessor (i.e. one or microprocessors) implementing one or more algorithms. - the gas source(s) contains a NO / N2 mixture containing less than 2000 ppmv of NO, the remainder being nitrogen, preferably less than 1000 ppmv of NO, the remainder being nitrogen, preferably, the therapeutic gas source contains a NO / N2 mixture containing from 250 to 900 ppm by volume of NO, the remainder being nitrogen, for example of the order of 800 ppm by volume of NO, the remainder being nitrogen. - the inspiratory branch and the expiratory branch of the patient circuit are connected to each other via a junction piece, in particular a Y-piece. - the gas source(s) comprises a gas container(s), in particular a pressurized gas cylinder(s) equipped with a gas distribution valve with or without an integrated pressure regulator (RDI). Preferably, the gas distribution valve is made of a copper alloy, such as brass, or stainless steel. Preferably, the gas container(s) is / are equipped with a protective cover arranged around the gas distribution valve, for example a cover is made of a polymer material (i.e. plastic), metal or combinations thereof. - the pressurized gas cylinder(s) contains, when full, a gas mixture, in particular NO / N2, at a pressure of at least 150 to 200 bar abs, or even at least 250 to 300 bar abs. - the flow sensor is of the mass flow meter or pressure differential type, or other.

[0015] Generally speaking, within the framework of the invention: - “ppmv” means parts per million by volume, - “%vol.” means percentage by volume. - “NO” means nitrogen monoxide. - “N2” means nitrogen. - “O2” means oxygen. - by "flow sensor" we mean a sensor designed for and capable of measuring and providing one or more flow signals or measurements proper or of the type measuring and providing one or more pressure signals or measurements which are then converted into flow by the control means. - the terms "means of / to / for" are considered to be completely equivalent and substitutable by the terms "device of / to / for", for example the terms "control means" can be replaced by "control device", the terms "valve means" can be replaced by "valve device", the "control means" can be replaced by "device of control "...

[0016] The invention will now be better understood thanks to the following detailed description, given for illustrative but non-limiting purposes, with reference to the appended figures among which:

[0017] [Fig-1] shows a diagram of an embodiment of an NO administration installation gaseous device according to the prior art comprising a gas humidifier arranged downstream of the medical ventilator.

[0018] [Fig.2] details the flow sensor of the installation of [Fig. 1].

[0019] [Fig.3] shows a diagram of an embodiment of an NO administration installation gaseous according to the invention comprising a fan with integrated humidifier.

[0020] [Fig.4] shows schematically an embodiment of the flow sensor with heating element of a gaseous NO administration installation according to the invention, in particular that of [Fig.3].

[0021] [Fig.l] shows schematically a conventional gas administration installation 10 used to supply an NO-based gas, i.e. a gas mixture containing NO, to a patient in need thereof for the purpose of treating a pulmonary pathology affecting this patient. This conventional installation 10 comprises a device or apparatus for supplying, i.e. delivering, NO 1 making it possible to monitor / follow and control the supply of an NO / N2 gas mixture. This NO / N2 gas mixture comes from one or more sources of NO / N2 gas mixture, conventionally one or more pressurized gas cylinders (not shown) containing the desired NO / N2 gas mixture, preferably a NO / N2 gas mixture containing between 200 and 2000 ppmv of NO (N2 remainder), typically between 400 and 1000 ppmv of NO (N2 remainder), for example 450 or 800 ppm vol. of NO (N2 remainder).

[0022] The gas cylinders are fluidically connected to the NO 1 supply device, via gas supply lines, such as flexible pipes or conduits or the like, which may be equipped with gas pressure regulating and / or monitoring devices, such as gas regulators, pressure gauges, etc. The gas supply lines are connected to one or more gas inlets of the NO 1 delivery device which supply an internal gas passage used to convey the gas within the NO 1 delivery device, i.e. into the external casing or frame of the NO 1 delivery device.

[0023] The NO 1 supply device generally also comprises an oxygen inlet fluidically connected, via an oxygen supply line, such as a flexible hose or the like, to an oxygen source, for example a pressurized oxygen cylinder or a hospital network, i.e. an oxygen supply pipe arranged in a hospital building.

[0024] The gas administration installation 10 further comprises a fan medical 3, i.e. a respiratory assistance device or the like, which provides a flow of respiratory gas containing oxygen, typically of the order of at least about 21% oxygen, such as air or an oxygen / nitrogen mixture (N2 / O2), or even pure oxygen.

[0025] The medical ventilator 3 and the NO 1 supply apparatus of the gas administration installation 10 are in fluid communication with a gas supply line or inspiratory branch 21 of a patient circuit 2. The gas supply line or inspiratory branch 21 is used to convey the gas flow to the patient, which is formed by mixing the oxygen-based flow (i.e. air or NO / N2 mixture) coming from the medical ventilator 3 and the flow containing NO, i.e. the NO / N2 gas mixture, delivered by the NO 1 supply device.

[0026] More precisely, the NO 1 supply device delivers or injects the NO / N2 mixture, for example at 450 or 800 ppmv of NO, into the gas supply line 21, via a conduit or injection line 4 which is fluidically connected to an outlet port 13 of the apparatus 1, so as to mix (at 5) the flow of NO / N2 with the flow of oxygen-based gas (with at least approximately 21% O2), e.g. air or an oxygen / nitrogen mixture, delivered by the medical ventilator 3 and conveyed by the inspiratory branch 21 of the patient circuit 2 so as to obtain a final mixture essentially containing NO at the desired dosage, nitrogen (N2) and oxygen (O2), and possibly unavoidable impurities (e.g. argon, CO2, NO2, etc.), i.e. a gas mixture NO / N2 / O2.

[0027] The inspiratory branch 21 further comprises a gas humidifier 6 arranged on the inspiratory branch 21, downstream of the site 5 where the injection of NO into the inspiratory branch 21 takes place. This gas humidifier 6 is therefore arranged outside the ventilator 3 and on the path of the gas flow, after injection of NO into the inspiratory branch 21. It makes it possible to humidify the gas flow, e.g. the gas mixture NO / N2 / O2, before it is administered to the patient to be treated, by means of a suitable respiratory interface 24, such as a tracheal intubation tube, a respiratory mask or the like.

[0028] A line for recovering the gases exhaled by the patient is also provided, forming the expiratory branch 22 of the patient circuit 2. The gas supply line or inspiratory branch 21 and the recovery line or expiratory branch 22 of the exhaled gases are connected to a connecting piece 23, preferably a Y-shaped piece. The inspiratory branch 21 is fluidically connected, upstream, to an outlet port 31 of the medical ventilator 3, such as a connector, fitting or the like, so as to recover and convey the oxygen-based gas, typically air or N2 / O2 mixture (containing approximately 21% O2) delivered by the medical ventilator 3, while the expiratory branch 22 conveying the exhaled gases is fluidically connected to an inlet port 32 of the medical ventilator 3, such as a connector, fitting or the like, so as to return to the medical ventilator 3 all or part of the flow of gases exhaled by the patient. The expiratory branch 22 of the exhaled gases may comprise one or more optional components, such as for example a CO2 elimination device, ie a CO2 trap, such as a hot tank or other, making it possible to eliminate the CO2 present in the gases exhaled by the patient or a filter or other.

[0029] A flow sensor 7, for example of the mass flow meter or pressure differential type, is arranged on the gas supply line or inspiratory branch 21, between the fan 3 and the humidifier 6, and is connected to the NO 1 delivery device, via one or more flow measurement lines 8. This flow sensor 7 is used to measure the flow rate of gas delivered by the fan 3, such as air or an N2 / O2 mixture, circulating in the inspiratory branch 21, upstream of the connection site of the injection conduit or line 4 where the NO / N2 / O2 gas mixture is produced. This makes it possible to more effectively regulate the delivery of the NO (i.e. N2 / O2) flow by the NO 1 delivery device since the flow rate measurements made by the flow sensor 7 are returned, via the flow measurement line(s) 8, to the control means of the NO 1 delivery device.

[0030] The NO 1 supply apparatus conventionally comprises a rigid housing, for example made of polymer, crossed by an internal gas passage (not visible), such as a gas conduit or the like, to convey the flow of NO / N2 supplied by the gas supply line(s) which is supplied by the NO / N2 mixture bottles.

[0031] The internal gas passage fluidly connects the gas inlet(s) of the NO 1 supply apparatus to the injection line 4, via the outlet port 13 of the apparatus 1, so as to convey the NO-based gas flow between them. Valve means (not shown), i.e. one or more valve devices, for example a plurality of solenoid valves arranged in parallel, preferably one or more proportional (solenoid) valves, are arranged on the internal gas passage to control the gas flow circulating therein towards the injection line 4.

[0032] More precisely, the valve means of the NO 1 supply apparatus are controlled by control means, i.e. one (or more) control devices, also arranged in the housing of the NO 1 supply apparatus, typically an electronic card comprising one (or more) microprocessor(s), typically one (or more) microcontroller(s), implementing one or more algorithms.

[0033] The control means make it possible in particular to adjust or control the gas flow rate by controlling the valve means, typically to open or close this or these valves, to obtain a gas flow rate determined and / or calculated by the control means from a value set / fixed by the user, and as a function of the gas flow rate, i.e. air, delivered by the ventilator 3 and measured by the flow sensor 7 arranged on the inspiratory branch 21 and connected to the NO 1 supply device, by the line(s) of flow measurement 8.

[0034] The internal gas passage of the NO 1 supply apparatus may also comprise one or more flow meters arranged upstream and / or downstream of the valve means, for determining the flow rate of NO-based gas circulating in the NO 1 supply apparatus. The flow meter may be of the pressure differential, mass or other type. It cooperates with the control means to provide them, again, with flow rate measurements of the NO / N2 flow, which measurements are processed by the control means in order to ensure efficient delivery of NO as a function in particular of the flow rate of O2-based gas supplied by the medical ventilator 50.

[0035] Usually, the NO 1 supply apparatus also comprises a graphical user interface or GUI comprising a graphical display 11, preferably a touch screen, i.e. a touch panel, used to display various information or data, icons, curves, alarms, etc., as well as virtual selection keys and / or blocks or windows, used in particular to make choices, selections or to enter information, such as desired values (e.g. flow rate, NO dosage, etc.), or any other information or data useful to the healthcare personnel. Preferably, the display is in color but it can also be in black and white.

[0036] The means for controlling the NO 1 supply apparatus comprising for example an electronic control card and a microprocessor control unit, typically a microcontroller or the like. The control means make it possible to control or command all the electromechanical elements of the apparatus 1. More precisely, the control card preferably integrates the control unit and is configured to control and further analyze the signals coming from the various components, such as the sensors...

[0037] The electrical power supply of the NO 1 supply apparatus, in particular of the components requiring electrical current to operate, such as the control means, the graphic display 11, etc., is conventionally provided by a source of electrical current and / or electrical power supply means (not shown), for example a connection to the mains current (110 / 220V) of the electrical cord and connection plug type, and / or one (or more) electrical power supply batteries, preferably rechargeable, and / or a current transformer. The electrical power supply of the medical ventilator 3 is provided in a similar manner, in particular by a connection to the mains current or an internal battery.

[0038] Finally, the installation 10 also comprises a gas sampling line 15 which fluidly connects the inspiratory branch 21 to the NO 1 supply device. It is fluidly connected (at 16), via a T-shaped connector 17 for example, as detailed in [Fig.l], to the gas supply line 21, between the humidifier 6 and the junction piece 23, i.e. the Y-shaped piece, typically in the immediate vicinity of the junction 23, and furthermore to an inlet port 12 of the NO 1 supply device, for example a port 12 carried by a connector, fitting or the like, allowing the connection of the gas sampling line 15, such as a flexible hose or the like. The gas sampling line 15 makes it possible to take gas samples from the inspiratory branch 21 of the patient circuit 2 and convey them to the NO 1 supply device where they are analyzed in an internal gas analyzer (not shown), that is to say within a calibration line comprising at least one sensor, in particular one or more electrochemical cells, electrically connected to the control means, in order to verify their conformity.Indeed, it is necessary to verify that the composition of the final gas is consistent with that of the desired NO / N2 / O2 gas mixture to be administered to the patient, in particular to ensure that it does not contain an excessive quantity of toxic NO2 species, that its oxygen content is not hypoxic, that it does not contain too high a NO2 content and that its NO content corresponds to the desired dosage, i.e. dose of NO to be administered by inhalation which is usually chosen by the healthcare staff, i.e. doctor or similar. This conformity verification is conventionally carried out by means of dedicated measuring means, typically NO2, NO and O2 sensors, for example electrochemical cells or similar, which must themselves be calibrated periodically, for example every week. The control means of the device 1 are configured to recover and treat, i.e.analyze the signals coming from the different sensors of the gas analyzer, which is arranged in the device 1, and to act in response to these signals, in particular to carry out a calibration of the sensors.

[0039] Preferably, the flexible pipe forming the inspiratory branch 21 is heated and comprises for this purpose an electrical resistor or the like supplied by an electrical cable 25, which makes it possible to avoid or minimize condensation of water in the inspiratory branch 21.

[0040] As detailed in [Fig.l] and [Fig.2], the flow sensor 7, typically of the mass flow meter type or other, is fluidically connected to the inspiratory branch 21 by means of connection connectors 9, at a measurement site located on the inspiratory branch 21, downstream of the fan 3 and upstream of the humidifier 6, that is to say between the fan 3 and the humidifier 6. Here, flow measurement lines 8 connect the flow sensor 7 to the control means, i.e. the control unit, of the NO 1 delivery device, in order to provide them with measurements of the gas flow rate coming from the fan 3, such as air or an N2 / O2 mixture, and circulating in the inspiratory branch 21, upstream of the connection site of the injection conduit or line 4 where the NO / N2 / O2 gas mixture is made.

[0041] However, such an arrangement is not desirable when the medical ventilator 3 incorporates gas humidification means, i.e. a humidifier device of gas, so that the gas humidifier 6 is removed.

[0042] In this case, the gas humidification device or means are integrated into the ventilator 3, i.e. either arranged in the ventilator 3 itself or associated with it to deliver a humidified gas flow, i.e. one loaded with water vapor. In other words, the gas flow containing oxygen, such as air or an O2 / N2 mixture (>21% O2 approximately), delivered by the medical ventilator 3 is humidified prior to its exit from the ventilator 3 or just after, and therefore contains a significant proportion of water (i.e. humidity) which will negatively impact, i.e. distort, the measurements made by the flow sensor 7 and lead to determining an erroneous flow rate of the gas flow.

[0043] Thus, it has been noted in practice that given that the gas mixture which passes through the flow sensor 7 is humid, water condensation is caused to form in the sensor 7, which causes flow measurement errors which are transmitted to the control means of the NO 1 supply apparatus, which are then caused to carry out erroneous calculations leading to an incorrect dosage of the NO injected into the flow circulating in the inspiratory branch 21, and possibly untimely triggering of alarms.

[0044] According to the invention, in order to solve this problem, it is proposed to replace the conventional flow sensor 7, used in the installation of [Fig.l], by a particular sensor 70 which is inserted in place of said conventional flow sensor 7, as illustrated in [Fig.3] and [Fig.4].

[0045] More precisely, [Fig. 3] schematizes an embodiment of a gaseous NO administration installation 10 according to the invention which is generally similar to that of [Fig. 1] (the elements in common will not be detailed because it is sufficient to refer to the explanations above), with the exception of the fact that the gas humidification 6 has been eliminated and that the fan 3 has been replaced by a fan 30 with an integrated humidifier, that is to say that the fan 30 comprises means or a gas humidification device used to humidify the gas containing oxygen, typically at least about 21% vol. of oxygen, i.e. air or N2 / O2 mixture, supplied by the fan 30 to the inspiratory branch 21 of the patient circuit 2.

[0046] In other words, the humidification of the gas is now carried out upstream of the flow sensor 70 which carries out the flow rate measurements of the gas flow leaving the fan 30 by means of one (or more) measuring cells 72 located on a control card, i.e. electronic card, integrated into the flow sensor 70, as shown diagrammatically in [Fig.4].

[0047] Therefore, so that the humidity present in the gas flow coming from the fan 30 does not disturb the flow rate measurements, the flow rate sensor 70 comprises heating means or a heating device 71, that is to say that it integrates (at least) a heating element at the level of the measuring cell 72, i.e. electronic card, of the sensor 70 making it possible to heat the internal walls 73 of the sensor 70 and thus avoid any condensation of water on these walls and / or formation of water drops at the level of the measuring cell 72.

[0048] Thus, the measurements made by the measuring cell 72 of the sensor 70 are no longer distorted and the control means which receive these measurements are then capable of calculating the dose of NO to be delivered to the patient as a function of the target concentration of NO set by the doctor, that is to say the desired dosage for the patient considered to be to be treated by administration of NO.

[0049] The flow sensor 70 is typically of the mass flow meter type or other.

[0050] It should be noted that in [Fig.3], the flow measurement line 8 is preferably a serial link connecting the flow sensor 7 to the control means, i.e. the control unit, of the NO 1 delivery device, in order to provide them with flow measurements carried out by the flow sensor 70.

[0051] More precisely, the heating element of the sensor 70 is of the resistive type, that is to say that it comprises an electrical resistance or the like, for example connected by a power supply wire to the NO 1 supply device. It is possible to vary the electrical power supplied to the heating element from 0 to 100% to modify the temperature.

[0052] In order to be able to control the heating of the flow sensor 70, heating activation means may be provided, such as a key, a button or the like, allowing the user to control the activation, i.e. a start, of the heating of the sensor 70 and possibly then a stop, i.e. to stop the heating of the sensor 70. Thus, the user can choose to heat the sensor 70, or even then to interrupt the heating of the sensor 70.

[0053] For example, the flow sensor 70 may comprise a tubular portion 75 comprising said (at least one) measuring cell 72. The tubular portion 75 comprises a lumen 74, i.e. internal passage, in fluid communication with the inspiratory branch 21 and therefore crossed by the flow of humid gas coming from the ventilator with integrated humidifier.

[0054] In other words, the gaseous NO administration installation 10 of the invention comprises the medical ventilator 30 with integrated humidifier which is fluidically connected to the inspiratory branch 21 of the patient circuit 2 and delivers thereto a humidified gas flow containing oxygen, such as air or an O2 / N2 mixture, or even oxygen, the flow sensor 70 arranged on the inspiratory branch 21 and comprising said at least one heating element 71 serving to prevent condensation of water vapor on the internal walls of the flow sensor 70, and the NO 1 supply apparatus fluidically connected to the inspiratory branch 21, downstream of the flow sensor 70 to inject therein the flow of gas based on NO, in particular an NO / nitrogen mixture, typically an NO / nitrogen mixture containing from 100 to 1000 ppmv of NO, the remainder being nitrogen.

[0055] Such a gas administration installation 10 according to the invention can be used to administer nitric oxide (NOi) by inhalation, i.e. the final mixture obtained NO / O2 / N2, to people, i.e. patients, suffering from acute pulmonary arterial hypertension, in particular to operate a dilation of their pulmonary vessels and an increase in their oxygenation by improving pulmonary gas exchange, in particular to treat Pulmonary Arterial Hypertension of the Newborn or PPHN, Acute Respiratory Distress Syndrome or ARDS observed, mainly in adults, or pulmonary hypertension (PH) in cardiac surgery in adults or children.

Claims

Claims

1. Installation for administering gaseous NO (10) comprising: - a medical ventilator with integrated or associated humidifier (30), fluidically connected to an inspiratory branch (21) of a patient circuit (2) to deliver thereto a humidified gas flow containing oxygen, such as air or an O2 / N2 mixture, - a flow sensor (70) arranged on the inspiratory branch (21), comprising at least one heating element (71), - and an NO supply apparatus (1) fluidically connected to the inspiratory branch (21) downstream of the flow sensor (70) to inject thereto a flow of gas based on NO, characterized in that: - the flow sensor (70) comprises a tubular portion (75) comprising at least one measuring cell (72), said tubular portion (75) being in fluid communication with the inspiratory branch (21),- the tubular portion of the flow sensor (70) comprises said at least one heating element (71) arranged so as to be able to heat the internal wall (73) of the tubular portion (75) of the sensor (70), and - the NO supply apparatus (1) comprises control means for modifying the electrical power supplied to said at least one heating element (71) in order to adjust the temperature of said at least one heating element (71).,

2. Installation according to claim 1, characterized in that said at least one heating element (71) is of the resistive type.

3. Installation according to one of the preceding claims, characterized in that said at least one heating element (71) is supplied with electric current by the NO supply apparatus (1).

4. Installation according to one of the preceding claims, characterized in that the flow sensor (70) is of the mass flow meter type.

5. Installation according to claim 1, characterized in that the tubular portion (75) of the flow sensor (70) is connected by fitting or screwing to the inspiratory branch (21) so as to ensure a fluidic continuity between them.

6. Installation according to claim 1, characterized in that the flow sensor (70) is connected to control means of the NO supply device (1) to transmit to them the flow measurements made by the measuring cell (72) of the flow sensor (70).

7. Installation according to claim 1, characterized in that it comprises heating activation means allowing the user to control activation of the heating of the flow sensor (70).

8. Installation according to claim 1, characterized in that the control means are configured to modify the electrical power supplied to said at least one heating element (71) in order to adjust the temperature of said at least one heating element (71) as a function of the quantity of water vapor within the flow sensor (70).

9. Installation according to claim 1, characterized in that the control means are configured to modify the electrical power supplied to said at least one heating element (71) in order to adjust the temperature of said at least one heating element (71) from a predefined power value, preferably stored.

10. Installation according to claim 1, characterized in that the control means are configured to modify the electrical power supplied to said at least one heating element (71) by delivering power information corresponding to a power between 0 and 100%.

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