NO gas administration system including a medical ventilator with integrated humidifier

Abstract

Title of the Invention: Gaseous NO Delivery System Comprising a Medical Ventilator with Integrated or Associated Humidifier. The invention relates to a gaseous NO delivery system (10) comprising a medical ventilator with an integrated or associated humidifier (30), fluidically connected to an inspiratory limb (21) of a patient circuit (2) to deliver a humidified gas stream containing oxygen, such as air or an O2 / N2 mixture, a flow sensor (70) arranged on the inspiratory limb (21), and an NO delivery device (1) fluidly connected to the inspiratory limb (21) downstream of the flow sensor (70) to inject a NO-based gas stream. 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: Gaseous NO administration system comprising a medical ventilator with integrated humidifier

[0001] The invention relates to a gaseous NO delivery system comprising a medical ventilator with integrated humidifier fluidically connected to an inspiratory branch of a patient circuit including a flow sensor with heating element, and an NO supply device fluidly connected to the inspiratory branch downstream of the flow sensor to inject a flow of NO-based gas, typically a 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 NOi treatment, commonly called an NO delivery installation, classically comprises one or more NO / N2 mixing cylinders supplying an NO delivery device, a medical ventilator, i.e. a respiratory support device, to deliver an oxygen-based respiratory gas (>21% vol. approx.), such as an O2 / N2 mixture, air or oxygen, a patient circuit with an inspiratory branch supplied with the gas flows from the medical ventilator and the NO delivery device, and a patient kit including 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. with 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 in order to avoid or minimize the risk of drying out the patient's airways due to the administration of a gas that is too dry.

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

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

[0007] This flow sensor measures the gas flow rate in the inspiratory limb and provides the flow measurements to the control means of the NO supply device to which it is connected. These flow 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 supplied to obtain the final mixture at the desired NO concentration. This NO / N2 flow is injected into the inspiratory limb, between the flow sensor and the gas humidifier, where it mixes with the oxygen-containing gas flow from the medical ventilator, e.g., air or the NO / N2 mixture.

[0008] If such an installation works perfectly with a conventional fan and humidifier arranged on the inspiratory branch downstream of the flow sensor, it has been observed in practice that flow measurement errors occur when the medical ventilator incorporates gas humidifier means, that is to say that 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 an "integrated" humidifier, the gaseous flow containing oxygen, such as air or an O2 / N2 mixture (>21% O2 approximately), is humidified before exiting the medical ventilator, therefore it contains a significant proportion of water (i.e. humidity) which will distort the measurements made by the flow sensor and thus lead to determining an erroneous flow rate of the gaseous flow.

[0010] This results primarily from water condensation forming in the sensor, which disrupts the flow measurements transmitted to the control means of the NO delivery device. This then leads to erroneous calculations within the control means, resulting in incorrect dosing of the NO injected into the flow circulating in the inspiratory limb and false alarm triggers.

[0011] One problem is therefore to propose an improved NO administration installation including a medical ventilator with integrated humidifier, in particular in which 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 a device 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 limb, - and a NO supply device fluidly connected to the ins branch a suction pipe 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 include one or more of the following features: - The medical ventilator delivers a humidified gas stream containing oxygen (at least 21% vol approximately), such as air or an O2 / N2 mixture, or even oxygen. - the fan incorporates gas humidifier 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 gaseous stream containing NO and nitrogen (N2). - The flow sensor is configured to perform flow measurements within the inspiratory limb. - the flow sensor is connected to the control means of the NO supply device in order to provide them with flow measurements. - the patient circuit, typically the inspiratory limb, 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 also includes an expiratory branch connecting the respiratory interface to the medical ventilator to return the gases exhaled by the patient, i.e. the 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 control means for the NO supply device are configured for process flow measurements (i.e. signal or value) in order to determine the gas flow circulating in the inspiratory limb at the location where the flow measurements are performed. The NO supply device includes control means for modifying the electrical power supplied to said at least heating element in order to adjust the temperature of said at least heating element. the control means are configured to modify the electrical power supplied to said at least heating element in order to adjust the temperature of said at least heating element according to, for example, the amount of water vapor within the flow sensor. Alternatively, the control means are configured to modify the electrical power supplied to said at least heating element in order to adjust the temperature of said at least heating element from a predefined power value, for example stored. The control means are configured to modify the electrical power supplied to said heating element by delivering a power information (e.g., value) corresponding to a power level between 0 and 100%. It includes heating activation means, for example, a key, a button, or the like, allowing the user to control the activation (i.e., start) of the flow sensor heating. The NO supply apparatus includes 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 (TOR) or proportional type 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 pilot means of the NO supply device. The internal gas circuit of the NO supply device carries the mixture no / n2. the means of controlling the NO supply device include a microprocessor(s), in particular a microcontroller(s). the means of controlling the NO supply device include at least one electronic board, preferably the electronic board includes the microprocessor(s). the means of controlling the NO supply device further include means of storage, in particular a computer memory, for example a flash memory or similar. the control means include 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 250 to 900 ppm by volume of NO, the remainder being nitrogen, for example around 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) includes a gas container(s), in particular a pressurized gas cylinder(s) equipped with a gas dispensing valve with or without an integrated regulator (IR). Preferably, the gas dispensing 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 dispensing valve; for example, a cover made of polymer material (i.e., plastic), metal, or combinations thereof. - the pressurized gas cylinder(s) contains, when full, a gaseous 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 differential pressure type, or other.

[0015] In general, within the scope of the invention: - "ppmv" means parts per million by volume, - "%vol." means percentage by volume. - "NO" refers to nitrogen monoxide. - "N2" refers to nitrogen. - "O2" refers to oxygen. - by "flow sensor" we mean a sensor designed for and capable of measuring and providing one or more flow signals or measurements, or of the type measuring and providing one or more pressure signals or measurements which are subsequently converted into flow by the control means. - The terms "means of / to / for" are considered entirely equivalent and interchangeable with the terms "device of / to / for", for example, the terms "piloting means" can be replaced by "piloting device", the terms "valve means" can be replaced by "valve device", the terms "control means" can be replaced by "control device" control "...

[0016] The invention will now be better understood with reference to the following detailed description, given by way of illustration but not limitation, with reference to the accompanying figures, among which:

[0017] [Fig-1] schematically illustrates an embodiment of a NO administration installation gaseous 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] schematically illustrates an embodiment of a NO administration installation gaseous according to the invention comprising a fan with integrated humidifier.

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

[0021] [Fig. 1] schematically illustrates a conventional gas delivery system 10 used to supply a NO-based gas, i.e., a gas mixture containing NO, to a patient requiring it for the treatment of a pulmonary condition affecting that patient. This conventional system 10 includes a NO supply, i.e., delivery, device 1 for monitoring / tracking and controlling the supply of a NO / N2 gas mixture. This NO / N2 gas mixture comes from one or more NO / N2 gas mixture sources, conventionally one or more pressurized gas cylinders (not shown) containing the desired NO / N2 gas mixture, preferably an NO / N2 gas mixture containing between 200 and 2000 ppmv of NO (remaining N2), typically between 400 and 1000 ppmv of NO (remaining N2), for example, 450 or 800 ppmv of NO (remaining N2).

[0022] The gas cylinders are fluidly 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 regulation and / or monitoring devices, such as gas regulators, pressure gauges... The gas supply lines are connected to one or more gas inlets of the NO 1 delivery device which feed an internal gas passage used to convey the gas within the NO 1 delivery device, i.e. into the casing or external housing of the NO 1 delivery device.

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

[0024] The gas administration installation 10 also includes a fan medical 3, that is to say a respiratory assistance device or similar, which provides a flow of respiratory gas containing oxygen, typically in the order of at least about 21% oxygen, such as air or an oxygen / nitrogen (N2 / O2) mixture, or even pure oxygen.

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

[0026] More specifically, the NO supply device 1 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 connects fluidly to an outlet port 13 of the device 1, so as to mix (at 5) the NO / N2 flow with the oxygen-based gas flow (with at least about 21% O2), e.g. air or an oxygen / nitrogen mixture, delivered by the medical ventilator 3 and carried by the inspiratory branch 21 of the patient circuit 2 so as to obtain a final mixture containing essentially NO at the desired dosage, nitrogen (N2) and oxygen (O2), and possibly unavoidable impurities (e.g. argon, CO2, NO2, ....), i.e. a gaseous mixture NO / N2 / O2.

[0027] The inspiratory branch 21 further includes a gas humidifier 6 arranged on the inspiratory branch 21, downstream of the site 5 where NO is injected into the inspiratory branch 21. This gas humidifier 6 is therefore arranged outside the ventilator 3 and in the path of the gas flow, after injection of NO into the inspiratory branch 21. It allows the gas flow, e.g. the NO / N2 / O2 gas mixture, to be humidified 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 patient exhalation gas recovery line, forming the expiratory branch 22 of the patient circuit 2, is also provided. The gas supply line or inspiratory branch 21 and the exhalation gas recovery line or expiratory branch 22 are connected to a connecting piece 23, preferably a Y-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 similar device, so as to recover and convey the oxygen-based gas, typically air or an N2 / O2 mixture (containing approximately 21% O2) delivered by the medical ventilator 3, while the expiratory branch 22 carrying the exhaled gases is fluidly connected to an inlet port 32 of the medical ventilator 3, such as a connector, fitting, or similar device, so as to return to the medical ventilator 3 all or part of the flow of gases exhaled by the patient. The expiratory limb 22 of the exhaled gases may include one or more optional components, such as a CO2 removal device, i.e. a CO2 trap, such as a hot tank or other, allowing the removal of 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 differential pressure 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 delivery device 1 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 point 5 of the duct or injection line 4 where the NO / N2 / O2 gas mixture is created. This allows for more efficient regulation of the NO (i.e., N2 / O2) flow rate by the NO delivery device 1, since the flow measurements taken by the flow sensor 7 are returned, via the flow measurement line(s) 8, to the control means of the NO delivery device 1.

[0030] The NO 1 supply device conventionally comprises a rigid casing, for example made of polymer, through which passes an internal (not visible) gas passage, such as a gas conduit or similar, to carry the NO / N2 flow brought by the gas supply line(s) which is supplied by the NO / N2 mixing cylinders.

[0031] The internal gas passage fluidly connects the gas inlet(s) of the NO supply device 1 to the injection line 4, via the outlet port 13 of the device 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 through it towards the injection line 4.

[0032] More specifically, the valve means of the NO 1 supplying device are controlled by control means, i.e. a (or more) control device, also arranged in the housing of the NO 1 supplying device, typically an electronic board comprising one (or more) microprocessor(s), typically a (or more) microcontroller, implementing one or more algorithms.

[0033] The control means allow, in particular, the adjustment or control of the gas flow rate by controlling the valve means, typically opening or closing 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 according to the gas flow rate, i.e. air, delivered by the ventilator 3 and measured by the flow sensor 7 arranged on the inspiratory limb 21 and connected to the NO supply device 1, by the line(s) flow measurement 8.

[0034] The internal gas passage of the NO1 supply device may also include one or more flow meters arranged upstream and / or downstream of the valve means, to determine the flow rate of NO-based gas circulating in the NO1 supply device. The flow meter may be of the differential pressure, 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 to ensure efficient NO delivery based, in particular, on the flow rate of O2-based gas supplied by the medical ventilator 50.

[0035] Typically, the NO supply device also includes a graphical user interface (GUI) comprising a graphical display 11, preferably a touchscreen, i.e., a touch panel, used to display various information or data, icons, graphs, alarms, etc., as well as virtual selection keys and / or keypads 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 healthcare personnel. Preferably, the display is in color, but it can also be in black and white.

[0036] The control means for the NO supply device 1 include, for example, an electronic control board and a microprocessor-based control unit, typically a microcontroller or similar. The control means allow for the control or command of all the electromechanical elements of the device 1. More specifically, the control board preferably integrates the control unit and is configured to control and also analyze the signals from the various components, such as the sensors...

[0037] The power supply for the NO₂ supplying device 1, in particular for components requiring electrical current to operate, such as the control means, the graphic display 11, etc., is conventionally provided by a power source and / or power supply means (not shown), for example, a mains power connection (110 / 220V) such as a power cord and plug, and / or one or more power supply batteries, preferably rechargeable, and / or a current transformer. The power supply for the medical ventilator 3 is provided in a similar manner, notably by a mains power connection or an internal battery.

[0038] Finally, the installation 10 also includes a gas sampling line 15 which fluidly connects the inspiratory branch 21 to the NO supply device 1. It is fluidly connected (at 16), via a T-connector 17 for example, as detailed in [Fig. 1], to the gas supply line 21, between the humidifier 6 and the junction piece 23, i.e., the Y-piece, typically in the immediate vicinity of the part of junction 23, and also to an inlet port 12 of the NO supply device 1, for example a port 12 carried by a connector, fitting or similar device, allowing connection of the gas sampling line 15, such as a flexible hose or similar device. The gas sampling line 15 allows gas samples to be taken from the inspiratory limb 21 of the patient circuit 2 and conveyed to the NO supply device 1 where they are analyzed in an internal gas analyzer (not shown), i.e. 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 conforms to 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 amount of toxic NO2 species, that its oxygen content is not hypoxic, that it does not contain an excessively high NO2 content, and that its NO content corresponds to the desired dosage, i.e., the dose of NO to be administered by inhalation that is usually chosen by the healthcare staff, i.e., physician or similar. This conformity verification is conventionally carried out using dedicated measuring devices, typically NO2, NO, and O2 sensors, for example, electrochemical cells or similar devices, which themselves must be calibrated periodically, for example, weekly. The control means of device 1 are configured to recover and process, i.e.to analyze the signals coming from the different sensors of the gas analyzer, which is arranged in device 1, and to act in response to these signals, in particular to perform a calibration of the sensors.

[0039] Preferably, the flexible tube forming the inspiratory limb 21 is heated and includes for this purpose an electrical resistance or similar supplied by an electrical cable 25, which makes it possible to avoid or minimize the condensation of water in the inspiratory limb 21.

[0040] As detailed in [Fig.1] 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 connecting connectors 9, at a measurement site located on the inspiratory branch 21, downstream of the fan 3 and upstream of the humidifier 6, i.e. between the fan 3 and the humidifier 6. Here, flow measurement lines 8 connect the flow sensor 7 to the control means, i.e. control unit, of the NO delivery device 1, in order to provide them with flow measurements of gas originating from the fan 3, such as air or an N2 / O2 mixture, and circulating in the inspiratory branch 21, upstream of the connection site 5 of the duct or injection 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 means for humidifying the gas, i.e. a humidifier device of gas, therefore the gas humidifier 6 is removed.

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

[0043] Thus, it has been observed 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 generates flow measurement errors which are transmitted to the control means of the NO supply device 1, which are then led to perform erroneous calculations leading to an incorrect dosage of the NO injected into the flow circulating in the inspiratory branch 21, and possibly untimely alarm triggering.

[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.1], with a special sensor 70 which is inserted in place of said conventional flow sensor 7, as illustrated in [Fig.3] and [Fig.4].

[0045] More specifically, [Fig.3] schematically illustrates an embodiment of a gaseous NO administration installation 10 according to the invention which is overall similar to that of [Fig.1] (the common elements will not be detailed as it suffices to refer to the explanations above), except that the gas humidification 6 has been removed and the fan 3 has been replaced by a fan 30 with an integrated humidifier, i.e. that the fan 30 includes means or a gas humidification device for humidifying 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 now takes place upstream of the flow sensor 70 which operates the flow measurements of the gas flow exiting the fan 30 by means of one (or more) measuring cell 72 located on a control card, i.e. electronic card, integrated into the flow sensor 70, as schematically shown in [Fig.4].

[0047] Therefore, in order to prevent the humidity present in the gas flow from the fan 30 from interfering with the flow measurements, the flow sensor 70 includes heating means or a heating device 71, i.e., it incorporates (at least) a heating element at the level of the measuring cell 72, i.e., the electronic board, of the sensor 70, enabling the internal walls 73 of the sensor 70 to be heated and thus preventing any water condensation on these walls and / or formation of water droplets at the level of the measuring cell 72.

[0048] Thus, the measurements taken by the measuring cell 72 of the sensor 70 are no longer distorted and the control means which receive these measurements are then able to calculate the dose of NO to be delivered to the patient according to the target concentration in NO set by the doctor, that is to say the desired dosage for the patient in question 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 on [Fig.3], the flow measurement line 8 is preferably a serial link connecting the flow sensor 7 to the control means, i.e. control unit, of the NO delivery device 1, in order to provide them with flow measurements operated by the flow sensor 70.

[0051] More specifically, the heating element of the sensor 70 is of the resistive type, that is to say, it includes an electrical resistance or similar, 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 control the heating of the flow sensor 70, heating activation means can be provided, such as a key, a button or other, 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 interrupt the heating of the sensor 70.

[0053] For example, the flow sensor 70 may include a tubular portion 75 comprising said (at least one) measuring cell 72. The tubular portion 75 includes a lumen 74, i.e. internal passage, in fluidic communication with the inspiratory branch 21 and thus traversed by the flow of humid gas from the fan with integrated humidifier.

[0054] In other words, the gaseous NO delivery 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 to it 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 heating element 71 serving to prevent the condensation of water vapor on the internal walls of the flow sensor 70, and the NO supply device 1 fluidically connected to the inspiratory branch 21, downstream of the flow sensor 70 to inject into it the NO-based gas flow, in particular an NO / nitrogen mixture, typically an NO / nitrogen mixture containing 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 by inhalation of nitric oxide (NOi), i.e. the final mixture obtained NO / O2 / N2, to persons, 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), - 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 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) 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).

5. Installation according to claims 3 and 4, characterized in that 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.

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

7. Installation according to one of claims 4 or 5, 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 fluid continuity between them.

8. Installation according to claim 4, characterized in that the flow sensor (70) is connected to means for controlling the supply device of NO (1) to transmit to them the flow measurements made by the measuring cell (72) of the flow sensor (70).

9. Installation according to claim 2, characterized in that the NO supply apparatus (1) comprises control means making it possible 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).

10. 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).

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