NO titration installation and method

Abstract

Title of the invention Installation and method for titrating NO The invention relates to a titration installation and method (1) for non-invasively determining an effective NO concentration to be administered to a patient suffering from a pulmonary pathology. An electrode belt (2) placed around the chest wall of the patient is used to carry out bioimpedance measurements of the lungs. An electrical impedance tomography (EIT) device (3) makes it possible to quantify a ventilation level and a perfusion level of the lungs from the bioimpedance measurements. A graphic display (4) displays a graphic representation of the ventilation and perfusion levels that have been quantified so as to determine whether the initial NO concentration corresponds to an effective NO concentration from the point of view of the ventilation / perfusion ratio. Abstract figure: Figure 1

Description

Title of the invention: Installation and method for titrating NO

[0001] The invention relates to a titration installation making it possible to determine, in a non-invasive manner, an effective NO concentration to be administered to a person, i.e. a patient, suffering from a pulmonary pathology requiring administration of inhaled NO, as well as a gas mixture usable in a titration method and such a non-invasive titration method.

[0002] Inhaled nitric oxide (NOi) is a standard treatment for treating people, i.e. patients, suffering from acute pulmonary arterial hypertension. When inhaled by the patient, inhaled nitric oxide, called "NOi" or "inhaled NO", dilates the pulmonary vessels and increases oxygenation by improving gas exchange. These properties are used to treat various medical conditions, such as Persistent Pulmonary Hypertension of the Newborn or PPHN (for Persistent Pulmonary Hypertension of the Newborn), Acute Respiratory Distress Syndrome or ARDS or pulmonary hypertension (PH) in cardiac surgery in adults or children, as described in particular by EP-A-560928, EP-A-1516639 and US-A-10,201,564.

[0003] Usually, a small quantity of gaseous NO (i.e. a few ppm vol.), diluted in nitrogen (N2) is injected and diluted in a gaseous flow containing oxygen, typically at least approximately 21% vol. of oxygen (O2), such as an N2 / O2 mixture or air, or even pure oxygen, which is conveyed by the patient circuit of a gas supply installation, and the final gaseous mixture obtained containing NO and oxygen is then inhaled by the patient. In general, it is administered to the patient by means of a suitable respiratory interface, such as a tracheal intubation tube, a respiratory mask, nasal prongs or the like, supplying the gaseous NO to the lungs of the patient to be treated.

[0004] The final NO concentration intended to be inhaled by the patient corresponds to a dosage determined by a doctor or similar depending in particular on the age of the patient in question. In general, it is between 1 and 80 ppm by volume (ppmv), typically of the order of 10 to 20 ppmv, depending on the population treated, i.e. newborns, children, adolescents or adults, and the disease to be treated, in the final NO / N2 / O2 gas administered to the patient, i.e. after injection of the NO / N2 mixture into the flow of gas containing oxygen (i.e. >20% vol. approximately) carried by the patient circuit and supplied by the respiratory interface.

[0005] The implementation of a NOi treatment usually includes one or more NO / N2 mixture bottles (or more rarely a NO generator), a NO delivery and monitoring device, a medical ventilator and a patient kit including the patient circuit and the respiratory interface, such as a tracheal intubation tube...or even other elements, such as a gas humidifier, a flow sensor or other.

[0006] In the context of treatment with iNO, the healthcare personnel, i.e. a doctor or similar, is faced with a recurring problem, namely determining whether a given patient responds or not to NO and what is the most suitable dosage for the patient in question, i.e. the most effective dose of NO for this patient. Indeed, since NO only acts in well-ventilated areas of the lungs, it is important to be able to visualize whether the ventilation associated with taking NO is the best to allow the NO to act effectively.

[0007] Currently, the dose of NO to be administered, i.e. the dosage most suitable for a given patient, is generally determined empirically and depends on various parameters, such as the age of the patient, the severity of the pathology, etc. It is therefore recommended to use a low dose at the start of treatment with iNO, for example 10 or 20 ppmv, whereas this dose may be ineffective for certain patients or, conversely, excessive for others.

[0008] Furthermore, not all patients respond in the same way to NO administration. Some respond favorably to the treatment, i.e., they are "responders" and can therefore be treated with iNO, whereas NO has no effect on others, i.e., they are not responders or "non-responders," and administering iNO to these patients is useless because it does not allow them to be treated. While determining a response to NO, i.e., whether a patient is a responder or not, can be relatively rapid, i.e., for example, 1 to 2 hours, some "responses" can be delayed and only available after much longer periods, for example, up to 6 hours or more. If the areas of the lungs are not ventilated, NO will not be able to act and therefore will not be able to cause dilation of the blood vessels.

[0009] However, it is understood that a long response time can be dangerous for the patient considered because, as long as the result of the test is not available, the healthcare staff does not know whether the patient is a responder or non-responder and / or whether the dose of iNO given to him is effective or unsuitable, i.e., too low or too high.

[0010] Furthermore, it is also important to be able to determine whether the non-response is due to the specific effect of NO or to the fact that the NO has not reached the level of the pulmonary alveoli.

[0011] Currently, to determine the effectiveness of NO in a given patient, an invasive analysis of blood gases is carried out (e.g. by arterial sampling) which can be associated, depending on the intended indication, with an analysis of pulmonary arterial pressure by means of an invasive central catheter, for example a Swan-Ganz catheter.

[0012] This method is therefore not ideal because it is invasive and also requires an interpretation of the results based on gas exchanges and the ventilation / perfusion ratio, which is a source of error. Indeed, if this method allows a response to be visualized, in particular an improvement in oxygenation, it does not allow a qualitative view of the gas exchanges occurring in the lungs of the patient in question, in particular the ventilation / perfusion ratio, nor a dynamic view of the effect of NO.

[0013] A problem is therefore to be able to determine more easily and in a non-invasive manner whether a person, i.e. a patient, is a responder or not to iNO treatment and furthermore to be able to correlate a response to a given dose of NO so as to be able to avoid stopping a treatment which has started due to "non-response", in particular a few hours after having started it.

[0014] A solution of the invention relates to a titration installation making it possible to determine, in a non-invasive manner, an effective NO concentration to be administered to a person, i.e. a patient, suffering from a pulmonary pathology requiring administration of NO by inhalation, comprising: - an electrode belt intended to be placed around the chest wall of said person to carry out bioimpedance measurements of the lungs of said person having inhaled an initial concentration of NO, - an electrical impedance tomography (EIT) device implementing at least one algorithm configured to quantify a ventilation level and a perfusion level of at least a portion of the lungs of said person from said bioimpedance measurements provided by the electrode belt, - and a graphical display configured to display at least one graphical representation of the ventilation level and the perfusion level having been quantified so as to enable a user to determine, from said at least one displayed graphical representation, whether the initial NO concentration corresponds to an effective NO concentration from the point of view of a ventilation / perfusion (V / P) ratio.

[0015] The titration installation of the invention has the advantage of being usable directly at the patient's bedside and therefore avoiding transport to an imaging department, which can be complicated for this type of patient who is often "severe", therefore difficult to transport within the hospital or similar. In addition, it has other advantages, in particular of validating a situation in which the NO will be able to act effectively in the patient in question given that, in order to act, the NO must already reach the pulmonary alveoli and then pass through them and, moreover, of being able to follow the effect of the NO and to visualize the modifications at the level of the exchanges gaseous occurring.

[0016] In the context of the present invention:

[0017] - ventilation corresponds to the quantity of oxygen which reaches the alveoli pulmonary and which will then pass into the capillaries located near these alveoli, i.e. alveolar-capillary exchanges. It allows us to know if a particular pulmonary area is well ventilated with functional alveoli allowing it to receive oxygen.

[0018] - perfusion corresponds to the quantity of oxygen recovered or captured by the blood vessels or capillaries that are opposite the alveoli. It allows us to know if a particular pulmonary area has blood capillaries near the alveoli, ensuring good alveolar-capillary exchanges with the passage of gaseous oxygen into the blood.

[0019] - the ventilation / perfusion ratio makes it possible to evaluate gas exchanges and therefore the oxygenation of a person, that is, the supply of O2 and the elimination of CO2. It reflects the adequacy between the quantity of gaseous O2 supplied to the lungs and the quantity exchanged at the level of the blood capillaries. In other words, gas exchanges between alveoli and capillaries require adequacy between ventilation and perfusion. In a pulmonary unit, i.e. alveolus + capillary, which has a normal ventilation / perfusion ratio (V7P= 1), the PAO2 is 100 mm Hg and the PACO2 is 40 mm Hg.

[0020] - ppmv means parts per million by volume.

[0021] - %vol means % by volume.

[0022] - EIT device means electrical impedance tomography device.

[0023] - “NO” is nitrogen monoxide.

[0024] Depending on the embodiment considered, the titration installation of the invention may comprise one or more of the following characteristics: - the graphic display is part of the electrical impedance tomography (EIT) device. - the graphical display is configured to display at least one graphical representation of the ventilation level and perfusion level having been quantified comprising at least one cross-sectional image of at least a portion of the lungs. - the graphic display is configured to display at least one graphic representation comprising at least one cross-sectional view of at least one portion of the lungs, in particular at least one TIE image of at least one portion of the lungs. - the graphic display is configured to display at least one graphic representation comprising at least one view (i.e. TIE image) in cross-section of the lungs divided into several regions. Indeed, it is advantageous to be able to visualize multiple lung regions because there may be regional differences in ventilation-perfusion (V / P) ratio. - said at least one view (i.e. TIE image) in cross-section of the lungs displayed is divided into 4 distinct pulmonary regions, i.e. 4 pulmonary quadrants reflecting distinct pulmonary regions of interest making it possible to visualize, for each region, a ventilation level (e.g. effective alveoli, number of alveoli involved, etc.) and a corresponding perfusion level (in particular capillary), i.e. operating in relation to this ventilation. - the 4 lung regions include an upper right region (HR), an upper left region (OL), a lower right region (LR), and a lower left region (LL). - the graphic display is configured to further display at least one graphic representation comprising a graph, preferably in bars or circular, corresponding to the levels of ventilation and perfusion having been quantified, in particular for all or part of the distinct pulmonary regions. - the bar or pie chart is of the bar-graph type, pie chart type, histogram, bar chart, or any other similar graph. - the graphic display is configured to display at least one graphic representation of the ventilation level and the perfusion level having been quantified from the bioimpedance measurements provided by the electrode belt, before and after inhalation by the patient of the given initial concentration of NO. - the tomography device comprising control means (i.e. controller or similar) controlling the display(s) on the graphic display. - the control means include at least one (micro)processor. - said at least one (micro)processor implements said at least one al algorithm. - the graphic display is configured to operate one or more color or black and white displays, preferably in color. - the determination of an initial concentration of NO corresponding to an effective concentration, from said at least one displayed graphical representation of the ventilation and perfusion levels, is done by comparison with:

[0025] . or a situation without NO called “basal”, in which the patient has not inhaled any NO (but air or oxygen) in order to visualize the effect of the initial dose of NO, including a non-effectiveness of the initial dose. A non-effectiveness (or very low effectiveness) of NO is explained in particular by insufficient ventilation for the NO to pass to the alveoli and play its role of dilating the vessels, i.e. vasodilator.

[0026] . either with another dose of NO, that is to say a different dose (principle of the titration), in order to determine the most effective dose of NO between the different doses tested.

[0027] According to another aspect, the invention also relates to a gaseous mixture containing gaseous nitric oxide (NO) for use in the treatment of a person suffering from a pulmonary pathology requiring administration by inhalation of said gaseous mixture, in which a non-invasive method is implemented for determining an effective concentration of NO to be administered to said person comprising the steps of:

[0028] a) carrying out bio-impedance measurements of the lungs of said person having inhaled an initial concentration of gaseous NO, by means of a belt of electrodes placed around the chest wall of said person,

[0029] b) processing the bioimpedance measurements obtained by means of an electrical impedance tomography (EIT) device configured to quantify at least one ventilation level and one perfusion level of at least a portion of the lungs of said person,

[0030] c) displaying at least one graphical representation of the ventilation level and the perfusion level having been quantified, on a graphical display (4), and

[0031] d) optionally repeating steps a) to c), for one or more other NO concentrations different from the initial concentration of gaseous NO, as long as said at least one graphic representation displayed on the graphic display does not show a ventilation / perfusion ratio corresponding to an effective concentration of NO.

[0032] Depending on the embodiment considered, the gas mixture of the invention may comprise one or more of the following characteristics:

[0033] - it is made up of nitrogen (N2) and NO.

[0034] - it contains less than 2,000 ppmv of NO.

[0035] - it contains from 1000 to 1500 ppmv of NO, the remainder being nitrogen, preferably less than 1000 ppmv of NO.

[0036] According to yet another aspect, the invention also relates to a non-invasive titration method for determining an effective concentration (i.e. dose) of NO to be administered to a person suffering from a pulmonary pathology requiring administration of NO by inhalation, comprising the steps of:

[0037] a) carrying out bio-impedance measurements of the lungs of said person having inhaled an initial concentration of gaseous NO, by means of a belt of electrodes placed around the chest wall of said person,

[0038] b) processing the bioimpedance measurements obtained by means of an electrical impedance tomography (EIT) device configured to quantify at least one ventilation level and one perfusion level of at least a portion of the lungs of said person, and

[0039] c) displaying at least one graphical representation of the ventilation level and the perfusion level having been quantified, on a graphical display.

[0040] In fact, the non-invasive method according to the invention used to determine an effective concentration of NO to be administered to a person makes it possible to determine whether the NO will act as a function of the ventilated areas of the lungs and to correlate the action and effectiveness of the product as a function of the ventilation / perfusion ratios of the lungs and therefore to determine the most suitable, i.e. effective, dose of NO.

[0041] Depending on the embodiment considered, the titration method of the invention may comprise one or more of the following characteristics:

[0042] - an optional step of repeating steps a) to c), for one or more other NO concentrations different from the initial concentration of gaseous NO, as long as said at least one graphical representation displayed on the graphical display does not show a ventilation / perfusion ratio corresponding to an effective concentration of NO.

[0043] - a step prior to step a), in which bio measurements are carried out impedance of the lungs of said person before any inhalation of the initial concentration of gaseous NO, for example after inhalation by the person of air or a nitrogen / oxygen mixture.

[0044] - the person is an adult, an adolescent, a child, a baby or a newborn.

[0045] - the person has pulmonary hypertension.

[0046] - the person suffers from pulmonary hypertension of the newborn or PPHN.

[0047] - the person is suffering from Acute Respiratory Distress Syndrome or ARDS.

[0048] - the person suffers from pulmonary hypertension (PH) caused by or resulting from from heart surgery.

[0049] - the most effective dose of NO is determined by comparing the representations graphs displayed on the graphic display for different NO contents between 0 (basal level) and 80 ppmv.

[0050] 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:

[0051] [Fig.l] shows a diagram of a titration installation according to the invention.

[0052] [Fig.2] schematizes a cross-sectional image obtained via an installation according to [Fig.l] in a patient who has not inhaled NO.

[0053] [Fig.3] schematizes a cross-sectional image obtained via an installation according to [Fig.l] in a patient having inhaled a dose of 15 ppmv of NO.

[0054] Generally speaking, the ventilation / perfusion (V / P) ratio makes it possible to evaluate the gas exchanges and therefore the oxygenation of a person, typically a patient, i.e. the supply of O2 which passes into the blood from the lungs and the elimination of CO2 carried by the blood and eliminated by the lungs.

[0055] An abnormal ventilation / perfusion ratio can result from a decrease in ventilation (V) or perfusion (P). One can therefore have a good idea of ​​a patient's oxygenation by determining this V / P ratio for the latter, in particular to evaluate the impact of NO inhalation in a patient suffering from a medical pulmonary disorder such as pulmonary hypertension.

[0056] Indeed, in a "responder" patient, iNO will cause vasodilation of the pulmonary vessels, leading schematically to an increase in their diameter, therefore in the exchange surface with the pulmonary blood vessels and capillaries and also in the blood flow in contact with the pulmonary alveoli, which promotes the passage of oxygen from the lungs to the blood and, conversely, the elimination of CO2.

[0057] On the other hand, in a "non-responder" patient, iNO has (almost) no effect and gas exchange is not improved due to administration of iNO. Such a non-response may be due to poor ventilation, i.e. the NO does not reach the capillaries and cannot play its role as a vasodilator. Conversely, if ventilation is sufficient, the best dose, i.e. the most effective, can also be chosen.

[0058] In order to ensure effective treatment with iNO, it is therefore essential to be able to determine whether the patient is a responder and whether the dose administered to him is the most effective dose for this patient.

[0059] Schematically, to be effective, the NO must reach the level of the pulmonary alveoli of the patient in question and these must be "in a state" to allow gas exchange. In addition, blood vessels must also be located opposite these alveoli in order to be able to dilate them.

[0060] However, as already explained, the usual techniques have limitations and can lead to stopping treatment several hours after its start due to a non-responding patient. Thus, the determination of blood gases only provides information on arterial oxygenation but has its limits with regard to ventilation and perfusion, therefore the V / P ratio.

[0061] Therefore, within the framework of the present invention, another technique is used, namely non-invasive pulmonary monitoring of the patient by electrical impedance tomography or “TIE tomography” (Electrical Impedance Tomography in English).

[0062] TIE tomography is a non-invasive imaging technique, easily usable at the patient's bedside, which allows a dynamic evaluation of pulmonary ventilation as well as a functional analysis of distinct pulmonary regions in a given patient, which allows the nursing staff to assess, in real time, the degree of homogeneity of ventilation and to detect possible ventilatory asynchronies. It also offers the possibility of measuring the variation in impedance at each respiratory cycle of the patient.

[0063] A TIE tomography therefore makes it possible to monitor the patient's ventilation in real time and continuously and to assess the repercussions of different settings of mechanical ventilation and, in the context of the invention, an effectiveness of the iNO treatment on regional ventilation. TIE tomography makes it possible to identify pulmonary aeration disorders and, with NO, makes it possible to individualize patient care.

[0064] [Fig.l] schematizes an embodiment of a titration installation 1 according to the invention making it possible to determine, in a non-invasive manner, an effective concentration of NO to be administered to a person, namely a patient, suffering from a pulmonary pathology requiring administration of NO by inhalation.

[0065] This installation 1 comprises a belt of electrodes 2 intended to be placed around the chest wall of the patient to be evaluated to carry out bioimpedance measurements of the lungs of the latter, who has previously inhaled an initial concentration of NO, typically a gas mixture containing NO and nitrogen, and at least approximately 21% vol. of oxygen.

[0066] The NO content in this gas mixture can be modified in order to evaluate the most effective dose of NO in the patient considered and also to ensure that the latter is a responder to iNO. For example, doses of NO ranging from 5 to 40 ppmv can be successively tested, in increments of 5 ppmv, i.e. 5, 10, 15... ppmv.

[0067] Generally, NO comes in gas cylinders containing 100 to 2000 ppmv of NO and the remainder nitrogen, and is diluted with air or an N2 / O2 mixture before being administered to the patient, via a respiratory interface, such as a breathing mask or tracheal tube.

[0068] It further comprises an electrical impedance tomography (EIT) device 3 implementing at least one algorithm configured to quantify a ventilation level (V) and a perfusion level (P) of at least part of the lungs, preferably of all of the lungs, in particular the base and the top of the two lungs to have a good view of the overall exchanges, from said measurements. bioimpedance provided by the electrode belt 2.

[0069] The impedance variations are measured by applying a low-intensity alternating current (eg 5 mA, 50-70 Hz) through the electrodes placed on the electrode belt 2 which is positioned at the level of the patient's rib cage. The images reconstructed on the screen are either static or dynamic. They represent the conductivity distribution at a given instant or the variation in the conductivity distribution between two instants. The images obtained allow the clinician to assess in real time the degree of homogeneity of the ventilation of the patient's lungs.

[0070] Furthermore, it also comprises a graphic display 4, such as a color display, configured to display one (or more) graphic representations of the ventilation and perfusion levels having been quantified in order to allow a user, such as a doctor or the like, to determine, from the graphic representation 5 displayed, whether the initial concentration of NO corresponds to an effective concentration of NO from the point of view of a ventilation / perfusion (V / P) ratio.

[0071] The graphical representation of ventilation and perfusion levels can take various forms, including EIT images.

[0072] EIT images reflect lung function, meaning that the displayed EIT images are of ventilated lung regions, i.e., ventilation level, rather than the morphological or anatomical structures of the lungs.

[0073] In addition to ventilation, the EIT device allows visualization of the regional distribution of pulmonary perfusion, which makes it possible to determine not only the distribution of ventilation but also the regional ventilation / perfusion (V / P) ratio.

[0074] In a healthy lung, ventilation is distributed fairly equally across the 4 quadrants of the image representing the regions (ROI 1-4) of the patient's lungs (ROI 1 = 28%, ROI 2 = 26%, ROI 3 = 25%, ROI 4 = 21%). Typically, the right lung (ROI 1, ROI 3) receives 50% to 55% of the overall ventilation (i.e. 100%).

[0075] Thus, in [Fig.2] and [Fig.3], the graphic representation displayed on the graphic display 4 comprises views 5 or TIE images representing the lungs 10 of the patient, shown here in cross-section, namely a first TIE image 10-1 showing the perfusion level (P) and a second TIE image 10-2 showing the ventilation level (V), which are displayed next to each other.

[0076] The lungs 10 are divided here into 4 distinct pulmonary zones or regions, i.e. 4 pulmonary quadrants reflecting distinct pulmonary regions of interest, making it possible to visualize, for each region, a ventilation level (e.g. effective alveoli, number of alveoli involved, etc.) and a corresponding perfusion level (notably capillary), i.e. operating in relation to this ventilation.

[0077] Here, the 4 lung regions include an upper right region HD, an upper left region HG, a lower right region BD and a lower left region B G. For each region, the % ventilation or perfusion has been indicated.

[0078] Furthermore, in [Fig.2] and [Fig.3], we see that an additional graphical representation tional or complementary 20 is displayed on the screen 4, below the lung view 10, namely here a bar graph or the like, representing a quantification of the ventilation and perfusion levels of the lung zones or regions appearing on the lung view 10, namely here the 4 aforementioned regions. For each region, the level (%) of the ventilation / perfusion ratio, i.e. V / P, is indicated depending on whether %V / P>1 or %V / P<1.

[0079] These graphic representations 10, 20 allow a user, typically a healthcare personnel, such as a doctor, to determine whether the initial concentration of NO corresponds to an effective concentration of NO from the point of view of a ventilation / perfusion ratio. Thus, a V / P ratio equal to 1 would reflect a situation in which gas exchanges would be maximum, i.e. the best.

[0080] Thus, [Fig.2] illustrates the patient's ventilation and perfusion levels in the absence of NO, i.e. before any inhalation of NO, namely a so-called "basal" state, whereas [Fig.3] represents the ventilation and perfusion levels after inhalation by the patient of 15 ppmv of NO.

[0081] By comparing these two graphs, the user can immediately see the changes caused by the inhalation of NO (iNO) on the ventilation and perfusion levels of the patient's lungs, and therefore the influence of the inhalation of NO on the ventilation / perfusion ratio (V / P).

[0082] As can be seen, NO has a beneficial effect since it improves perfusion in well-ventilated areas.

[0083] For information, [Fig.2] and [Fig.3] also give the patient's oxygen saturation (SpO2) in the absence and presence of NO. As can be seen, this increased after inhalation of NO, which confirms the improvement in the ventilation / perfusion (V / P) ratio in the presence of 15 ppmv of NO.

[0084] Further imaging may be required to verify whether other NO contents, e.g., 20 or 25 ppmv NO, further improve the ventilation / perfusion (V / P) ratio.

[0085] In any case, by doing so, the healthcare staff can determine whether or not the patient is a responder to iNO and, if so, the most effective concentration of NO for the patient in question.

[0086] When the graphic representation 10, 20, for example a TIE 5 image of lungs, displayed on the graphic display 4 does not show a V / P ratio corresponding to an effective concentration of NO for an inhaled concentration of NO given, which is different from that obtained for the initial concentration of gaseous NO (i.e. the basal state), i.e. no improvement or insufficient improvement, the nursing staff can then decide to increase the dose of NO administered to the patient, then see the effect of this increase on an updated graphic representation 10, 20, i.e. a new TIE image 5 for example displayed on the graphic display 4.

[0087] In other words, when a notable effect is obtained, the healthcare staff can conclude that the patient is a responder and that the dose of NO administered to him is the most effective. The patient's treatment can then be continued on this basis. Conversely, if no notable effect is obtained despite an increase in the doses of NO administered, the healthcare staff can conclude that the patient is a non-responder and stop the patient's treatment with iNO and opt for an alternative therapeutic treatment.

[0088] [Fig.4] is an alternative graphical representation 30 of the ventilation levels and perfusion, in particular the ventilation / perfusion ratio V / P.

[0089] The 3 graphs presented represent the basal state before administration of NO, and two states for which doses of 10 and 20 ppmv of NO were inhaled by the patient.

[0090] For each graph, ventilation 31 and perfusion 32 values ​​measured in the 4 regions (called ROI1 to ROI4) of the lungs of [Fig.2] are represented (in the form of points connected by lines) as a function of the ventilation / perfusion ratio V / P (%)•

[0091] This visualization of the evolution of ventilation / perfusion V / P (%) which can be displayed on screen 4, again makes it possible to see if the patient is responding and, in this case, which dose is the most effective.

[0092] Here, it is the dose of 20 ppm of iNO which is the most effective since, for this dose (see graph on the right), we see that the points corresponding to the ventilation 31 and perfusion 32 values ​​merge, which shows an optimal ventilation / perfusion ratio V / P, i.e. 100%, for the two regions considered, here the ROI2, ROI3 regions.

Claims

Claims

1. Titration installation (1) for determining, in a non-invasive manner, an effective NO concentration to be administered to a person suffering from a pulmonary pathology requiring administration of NO by inhalation, comprising: - an electrode belt (2) intended to be placed around the chest wall of said person to carry out bio-impedance measurements of the lungs of said person having inhaled an initial concentration of NO or air, - an electrical impedance tomography (EIT) device (3) implementing at least one algorithm configured to quantify a ventilation level and a perfusion level of at least part of the lungs from said bio-impedance measurements provided by the electrode belt (2),and - a graphical display (4) configured to display at least one graphical representation of the ventilation level and the perfusion level having been quantified so as to enable a user to determine, from said at least one graphical representation (5) displayed, whether the initial NO concentration corresponds to an effective NO concentration from the point of view of a ventilation / perfusion (V / P) ratio.,

2. Installation according to claim 1, characterized in that the graphic display (4) is part of the electrical impedance tomography (EIT) device (3).

3. Installation according to claim 1, characterized in that the graphic display (4) is configured to display at least one graphic representation of the ventilation level and the perfusion level having been quantified comprising at least one cross-sectional image of at least part of the lungs.

4. Installation according to claim 3, characterized in that the graphic display (4) is configured to display at least one graphic representation comprising at least one view of at least part of the lungs, in particular a cross-sectional view.

5. Installation according to claim 4, characterized in that the graphic display (4) is configured to display at least one graphic representation comprising at least one view of the lungs divided into several regions, in particular a cross-sectional view.

6. Installation according to one of claims 1 or 3, characterized in that the graphic display (4) is configured to display, in addition, at least one graphic representation comprising a bar or circular graph corresponding to the ventilation and perfusion levels having been quantified.

7. Installation according to claim 1, characterized in that the graphic display (4) is configured to display at least one graphic representation of the ventilation level and the perfusion level having been quantified from the bio-impedance measurements provided by the electrode belt (2) before and after inhalation by the patient of the given initial concentration of NO.

8. Installation according to claim 1, characterized in that the tomography device (3) comprises control means controlling the display(s) on the graphic display (4).

Images