Device for inhaled nitric oxide therapy

Abstract

A device for iNO therapy comprises a sensor unit for detecting a methemoglobin level in the blood of the treated patient, and a control unit connected thereto in data communication. The control unit is configured such that the methemoglobin level in the blood of the patient is continuously determined and displayed on a display unit. The control unit may be configured such that, in the event of a predetermined threshold value being exceeded, an alarm signal is issued and / or the supply of nitric oxide-containing therapy gas to the patient is reduced.

Description

[0001] MG 25339 30.01.2025

[0002] 1

[0003] Device for inhaled nitric oxide therapy

[0004] The invention relates to a device for inhalational nitric oxide therapy, comprising a device for supplying a respiratory gas to a patient, which is equipped with a respiratory gas supply line and a ventilation interface, a device for introducing a therapeutic gas containing nitric oxide into the respiratory gas, which is equipped with a gas source for the therapeutic gas and with a therapeutic gas supply line opening into the respiratory gas supply line and / or into the ventilation interface, a control unit cooperating with a control valve for regulating the gas flow through the therapeutic gas supply line, and a display unit connected to the control unit for visualizing therapy-relevant information.

[0005] In inhaled nitric oxide therapy (iNO therapy), nitric oxide is administered via the respiratory tract. A therapeutic gas containing nitric oxide (NO) is introduced into the respiratory flow, which is delivered to the patient via a breathing gas supply line. The concentration of therapeutic gas in the breathing gas used in iNO therapy, and thus the flow rate of the administered therapeutic gas, is usually preset before the start of therapy and maintained throughout the entire duration of the therapy or at least a portion thereof. The efficacy of the medication must be ensured through secondary monitoring. This monitoring must consider not only the positive effects of the therapeutic gas but also any undesirable side effects.In the case of iNO therapy, in addition to the irritating effect of nitric oxide (NO2) on the patient's airways—NO2 being a byproduct of nitric oxide and always present in trace amounts in the therapeutic gas—particular attention must be paid to the formation of methemoglobin (metHB) in the patient's blood, which is promoted by the administration of nitric oxide. Methemoglobin is a derivative of hemoglobin that, unlike hemoglobin, is unable to transfer oxygen absorbed in the lungs to the body tissues. At higher concentrations, it leads to methemoglobinemia with significant health risks for the patient; for example, at a concentration of MG 25339 30.01.2025.

[0006] 2

[0007] Cyanosis can be observed at 15% metHB of the total hemoglobin in the blood of an adult; a concentration of 40% metHB is fatal.

[0008] While continuous measurement of the NO2 content in the inhaled air is now offered as standard in iNO therapy devices currently on the market, and compliance with maximum permissible limits is ensured by an alarm management system of the therapy device, there are no such safeguards for monitoring the accumulation of metHB in the blood.

[0009] Only in pediatrics is there a guideline to discontinue therapy if a metHB value exceeds 4%; however, this is usually monitored manually as part of routine blood gas analyses and is therefore associated with considerable personnel effort and a high degree of uncertainty. In adult therapy, an upper limit of 7% metHB is under discussion, but compliance with this limit is not currently monitored.

[0010] The invention is therefore based on the objective of minimizing health risks for a patient due to methemoglobinemia as a side effect of iNO therapy.

[0011] This problem is solved in a device of the type and purpose mentioned above by the fact that the control unit is connected to a sensor unit for determining the level of methemoglobin in the patient's blood and the control unit is set up so that, according to a predefined program, information about the methemoglobin concentration in the patient's blood, determined continuously or at predefined time intervals by the sensor unit, is recorded and visualized on the display unit.

[0012] According to the invention, the metHB concentration in the blood of a patient undergoing iNO therapy is monitored by means of a sensor device that continuously or at predetermined intervals transmits information about the methemoglobin level in the blood to the control unit for further processing. The processing of the information by the control unit consists at least of determining a value for the metHB concentration from the information and transmitting this value. MG 25339 30.01.2025

[0013] 3

[0014] The display unit visualizes the metHB concentration as a numerical value and / or in graphical form. In this way, the concentration of metHB in the patient's blood is continuously monitored, preventing any accumulation to levels that would be unnoticed by the therapy device and thus endangering health.

[0015] The control unit can also be configured so that, if a preset limit for the metHB concentration is exceeded, warning signals of various kinds can be emitted via an alarm routine of a control program stored in the control unit. Preferably, the control unit is configured so that, if a predetermined limit for the methemoglobin concentration in the patient's blood is exceeded, the control unit sends a control command to emit a warning signal, for example in the form of an acoustic or visual signal, to the display unit and / or to an emergency signal transmitter connected to the control unit.

[0016] In an advantageous embodiment of the invention, the control unit is arranged such that, if a predetermined limit value for the methemoglobin concentration in the blood of the treated patient is exceeded, the control unit sends a signal to the control valve to reduce or stop the supply of therapy gas via the therapy gas supply line.

[0017] Advantageously, the control unit can also incorporate a control algorithm that regulates the flow rate of the therapeutic gas supplied to the patient's breathing gas via the therapy gas supply line, depending on the methemoglobin concentration in the patient's blood as determined by the sensor unit. Preferably, the control algorithm is designed to also incorporate other measured parameters, such as the NO2 concentration in the patient's breathing gas, into the control process.

[0018] Another advantageous embodiment of the invention provides that the control unit is connected to a data interface for wired or wireless data transmission and that the control unit is configured to transmit information about the methemoglobin concentration in the patient's blood to a MG 25339 30.01.2025

[0019] 4

[0020] The monitoring device is connected to a wired or wireless interface, such as Bluetooth, WLAN, or radio, and is capable of exchanging data. This monitoring device could be, for example, a therapist's mobile device or a stationary computer installed in a central control station of an intensive care unit or intermediate care unit. The monitoring device can display, for example, the current metHB concentration and / or emit a warning signal if a predefined limit is exceeded. This configuration enables, in particular, remote monitoring of patients and / or the simultaneous monitoring of multiple patients.

[0021] Preferably, the sensor unit is equipped with an optical detection system for determining metHB concentration. For example, similar to a pulse oximeter, the sensor unit measures the reflection or transmission of specific light frequencies from the patient's tissue that are selectively absorbed by metHB and calculates an absorption spectrum of the blood from this data. In this case, the sensor unit has, for example, one or more light-emitting diodes emitting at the corresponding frequency as transmitters and a photodiode sensitive in this frequency range as a receiver. The measurement results obtained by the sensor unit are then compared in the sensor unit or the control unit with a stored absorption spectrum of blood with a known metHB concentration, and information about the methemoglobin concentration in the blood of the treated patient is derived from this comparison.

[0022] The sensor unit is preferably designed to be non-invasively and securely, yet detachably, attached to a part of the patient's body during iNO therapy. For example, the sensor unit is designed as a clip that is attached to a patient's finger, toe, or earlobe, or as a patch sensor that is adhered to a patient's body surface.

[0023] The therapeutic device according to the invention enables safe inhaled NO therapy that does not necessarily require monitoring by intensive care. This expands the possibilities for inhaled NO therapy in diseases such as MG 25339 30.01.2025

[0024] 5

[0025] CF and COPD can also be extended for intermediate care or home therapy applications.

[0026] An embodiment of the invention will be explained in more detail with reference to the drawing. The single drawing (Fig. 1) schematically shows a device according to the invention for inhalational nitric oxide therapy.

[0027] The device 1 shown in Fig. 1 has a control unit 2 through which a metering line 3 is routed, the metering line being equipped with a control valve 4. The metering line 3 is connected via a connection port 5 to a source, for example a pressurized gas cylinder 6, for supplying a therapeutic gas containing nitric oxide. The therapeutic gas is, for example, pure nitric oxide or a gas mixture containing, in addition to nitric oxide, nitrogen and / or a noble gas. For example, the therapeutic gas consists of a volume fraction of between 450 ppm and 1000 ppm nitric oxide, the remainder being nitrogen. Via a further connection port 7, the metering line 3 is connected via a therapeutic gas supply line 8, which opens into a breathing gas supply line 10 at a mixing point 9.

[0028] The breathing gas supply line 10 serves to supply a breathing gas from a ventilator (not shown) to a patient 11. A pressure-controlled valve 12 in the breathing gas supply line 10 prevents exhaled gas from flowing back from the patient 11 through the breathing gas supply line 10. The breathing gas is, for example, an air-oxygen mixture, medical air (aer medicalis), or an oxygen-nitrogen mixture. The breathing gas supply line 10 opens into a ventilation interface 13, such as a breathing mask, placed on the patient 11. A breathing gas outlet 14 leads from the ventilation interface 13 to remove the breathing gas exhaled by the patient 11. Another pressure-controlled valve 15 in this outlet prevents exhaled air from flowing back to the patient 11 during the patient's breathing activity.

[0029] The metering line 3 and the control valve 4 are housed in a casing 16 of the control unit 2, which also contains a display unit 17, for example a screen, an operating panel 18 and an electronic MG 25339 30.01.2025

[0030] 6

[0031] Control unit 20 is located there. Operating panel 18 and display unit 17 can also be combined, for example, in a touchscreen. Operating panel 18, display unit 17, and control valve 4 are in data communication with control unit 20 and, in particular, enable the setting of a gas flow through the metering gas line 3 and its display on display unit 17.

[0032] Optionally, the control unit 20 can be equipped with an interface 21 for wired or wireless communication, through which data can be transmitted to an external communication device (not shown here), for example, a therapist's mobile device, and / or control can be carried out by the external communication device. Likewise, an emergency signal transmitter 22, which communicates with the control unit 20, can be provided and emits an acoustic and / or visual emergency signal in the event of a predetermined incident.

[0033] Furthermore, the control unit 20 is data-connected to a sensor unit 23. The sensor unit 23 is a measuring device that, for example, similar to a pulse oximeter, is non-invasively attached to a finger of the patient 11 and is suitable for recording information about the methemoglobin (metHB) content in the patient's blood. For example, the sensor unit 23 is equipped with optical detection means such that an absorption spectrum characteristic of methemoglobin is recorded, and a value for the metHB level in the patient's blood is calculated from this in the sensor unit 23 or in the control unit 20.

[0034] During operation of the device 1, a connection valve 24 on the compressed gas cylinder 6 is opened, thus establishing a flow connection for the therapeutic gas with the breathing gas supply line 10. The flow rate of the therapeutic gas through the metering line 3 is regulated by a corresponding input on the control panel 18 via the control valve 4 according to a program predefined in the control unit 20. Additional data, such as the duration of the therapeutic gas supply, specific patient data, or an indication, can be entered on the control panel 18. MG 25339 30.01.2025

[0035] 7

[0036] During the course of therapy, the administration of nitric oxide into the patient's blood may lead to increased metHB production. To prevent any associated health problems for the patient, the sensor unit 23 continuously or at predetermined intervals determines the metHB level in the patient's blood and transmits this information to the control unit 20. The resulting metHB concentration value is displayed on the display unit 17. If the metHB concentration exceeds a certain maximum limit, for example, 4% for children or 7% for adults, the control unit 20 can trigger a warning signal on the display unit 17 and / or the emergency signal transmitter 22, and / or transmit a warning message to the external communication device via the interface 21.In this case, the control unit 20 preferably also controls the control valve 4 to reduce or completely stop the addition of therapeutic gas to the patient's breathing gas.

[0037] Furthermore, the control unit 20 can be data-connected to additional sensors for determining therapy-relevant parameters, for example, to a sensor 25 arranged downstream of the mixing point 9 in the breathing gas supply line 10 for the continuous determination of the NO2 concentration in the gas inhaled by the patient 11. Similar to the previously described monitoring of the metHB concentration in the blood, it can be provided that if a predetermined limit value of the NO2 concentration in the patient's breathing gas 11 is exceeded, the control unit 20 initiates the issuance of a warning signal and / or the reduction of the therapy gas supply.

[0038] Furthermore, a control algorithm can be stored in the control unit 20, which regulates the flow rate of therapeutic gas supplied to the breathing gas depending on the metHB concentration in the patient's blood 11. For example, the control algorithm can provide that the control valve 4 is automatically reopened if the metHB level subsequently falls back into a non-critical range after the therapeutic gas supply has been blocked. Such a control algorithm can also take into account other measured parameters, such as the NO2 concentration in the breathing gas measured by sensor 25. MG 25339 30.01.2025

[0039] 8

[0040] With the device according to the invention, the metHB level in the blood of patient 11 can be continuously monitored and taken into account when administering the nitric oxide-containing therapeutic gas. Health impairments of patient 11 associated with an elevated metHB level in the blood caused by iNO therapy can thus be largely avoided. MG 25339 30.01.2025

[0041] 9

[0042] Reference symbol list

[0043] 1 Device

[0044] 2 Control unit

[0045] 3 Dosing lines

[0046] 4 Control valve

[0047] 5 connection nozzles 6 pressurized gas cylinder

[0048] 7 Connection nozzles 8 Therapy gas supply line 9 Mixing point

[0049] 10 Breathing gas supply line 11 Patient

[0050] 12 valve

[0051] 13 Ventilation interface 14 Breathing gas exhalation 15 Valve

[0052] 16 cases

[0053] 17 Display unit

[0054] 18 Control panel

[0055] 19 - 20 Control unit

[0056] 21 Interface

[0057] 22 emergency signal transmitters

[0058] 23 Sensor unit

[0059] 24 Connection valve 25 NO2 sensor

Claims

MG 25339 30.01.2025 10 Patent claims 1. Device for inhalational nitric oxide therapy, comprising a device for supplying a breathing gas to a patient (11), which is equipped with a breathing gas supply line (10) and a ventilation interface (13), with a device (2) for introducing a therapy gas containing nitric oxide into the breathing gas, which is equipped with a gas source (6) for the therapy gas and with a therapy gas supply line (8) opening into the breathing gas supply line (10) and / or into the ventilation interface (13), with a control unit (20) cooperating with a control valve (4) for regulating the gas flow through the therapy gas supply line (8) and with a display unit (17) connected to the control unit (20) for visualizing therapy-relevant information, characterized by that the control unit (20) is connected to a sensor unit (23) for determining the level of methemoglobin in the patient's blood (11) and the control unit (20) is set up so that, according to a predefined program, information about the methemoglobin concentration in the patient's blood (11) is continuously or at predefined time intervals determined by the sensor unit (23) and visualized on the display unit (17).

2. Device according to claim 1, characterized in that the control unit (20) is configured such that, when a predetermined limit value for the methemoglobin concentration in the patient's blood (11) is exceeded, the control unit (20) issues a control command to send a warning signal to the display unit (17) and / or to an emergency signal transmitter (22) connected to the control unit (20).

3. Device according to claim 1 or 2, characterized in that the control unit is configured such that, when a predetermined limit value for the methemoglobin concentration in the patient's blood (11) is exceeded, a signal is sent to the control valve (4) to reduce or stop the supply of therapeutic gas via the therapeutic gas supply line. MG 25339 30.01.2025 11 4. Device according to one of the preceding claims, characterized in that a control algorithm for controlling the control valve (4) is stored in the control unit (20), by means of which the flow rate of the therapy gas supplied via the therapy gas supply line (8) into the breathing gas of the patient (11) can be controlled depending on a methemoglobin concentration in the blood of the patient (11) and optionally other measured parameters.

5. Device according to one of the preceding claims, characterized in that the control unit (20) is connected to an interface (21) for wired or wireless data transmission and the control unit (20) is configured so that information about the methemoglobin concentration in the blood of the patient (11) can be transmitted to a control device connected to the interface (21).

6. Device according to one of the preceding claims, characterized in that the sensor unit (23) is equipped with an optical detection system for determining information about the methemoglobin concentration in the blood of the patient (11).

7. Device according to one of the preceding claims, characterized in that the sensor unit (23) can be connected non-invasively to a part of the patient's body (11), such as a finger, a toe or an earlobe, in a fixed but detachable manner.

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