Lung ventilation device and method of operating the same

Abstract

A lung ventilation device for delivering a ventilation gas of a desired volume at a desired pressure to a patient comprises: - a cylinder-piston unit (21) having a cylinder (211) and a piston (212), defining an operating chamber (3) for selectively receiving a first gas under pressure and a ventilation chamber (4) for selectively receiving the ventilation gas under pressure provided to the patient; - a device for regulating the flow entering and leaving the operating chamber and the ventilation chamber; - a sensor for detecting the pressure in the operating chamber and the ventilation chamber during use; - one position detector (29) configured to detect the position of the piston in the cylinder; - one acquisition and processing unit (6) for controlling the device for regulating the flow based on the position of the piston and the pressure in the chamber so as to deliver the ventilation gas of the desired volume at the desired pressure to the patient.

Description

Technical Field

[0001] The present invention relates in particular to a pulmonary ventilator suitable for use in the controlled ventilation of patients with respiratory failure and / or patients in intensive care units or operating rooms.

[0002] The present invention also relates to a method of operating a ventilator.

Background Art

[0003] In the state of the art, ventilators are known that are used to provide respiratory assistance to patients. Such pulmonary ventilators, for example those disclosed in Patent Document 1, Patent Document 2, Patent Document 3 and Patent Document 4, each comprise an electromechanical device configured to receive air from an external supply source for the device, mix it with oxygen and send it towards the patient's respiratory system. The operation of such an electromechanical device is assisted by sensors and actuators (for example valves, heaters, humidifiers etc.) incorporated in the device and is configured to monitor the physical parameters of the air-oxygen mixture supplied to the patient thus obtained and modify them if necessary, so that the air-oxygen mixture can reach the patient's lungs in a state adapted to physiological respiratory activity. In the market, conventional pulmonary ventilators may be distinguished into stationary ventilators or portable ventilators, which differ with respect to structure and characteristics. Conventional pulmonary ventilators (both stationary and portable) may also be divided into volume-controlled ventilators and pressure-controlled ventilators.

[0004] Volume-controlled ventilators are configured to regulate the volume of ventilation gas delivered to the patient during respiratory activity. This volume corresponds to the tidal volume set by the medical staff, i.e. the determined amount of air-oxygen mixture entering and leaving the lungs during each respiratory activity. These volume-controlled ventilators suffer from several drawbacks. In fact, they do not take into account the characteristics of the respiratory system of the patient receiving ventilation (airway resistance or lung compliance) and therefore, - Due to the reduced lung compliance of patients receiving ventilation due to a restricted process, alveolar rupture (barotrauma) may be caused by an unbalanced increase in alveolar pressure. - Since the alveolar pressure does not reach a level sufficient to ensure alveolar gas exchange, an insufficient oxygen supply (hypoxia) may be caused by an increase in the patient's lung compliance or leakage of ventilation gas from the ventilation duct connected to the patient, for example due to leakage.

[0005] Conversely, a pressure-controlled ventilator can compensate for a small amount of leakage that may occur in the ventilation circuit. However, the tidal volume delivered by them varies greatly depending on changes in the characteristics of the patient's respiratory system. In particular, - An increase in respiratory resistance and / or a decrease in compliance may lead to a risk of hypoventilation, while - A decrease in respiratory resistance and / or an increase in compliance may lead to volotrauma (excessive tidal volume).

[0006] An example of a conventional ventilator is disclosed in Patent Document 5. In Patent Document 5, the lung ventilator uses a double delivery cylinder-piston unit connected between a ventilation gas suction circuit and a gas delivery circuit delivered to the patient. This ventilator also includes an electric motor unit and one shaft. One shaft is connected to the electric motor on one side in a known manner and firmly connected to the piston of the cylinder-piston unit on the other side. The overall dimensions of this ventilator also depend on the non-negligible overall dimensions of the electric motor that drives the cylinder-piston unit, so it is difficult to use as a portable ventilator. Moreover, due to the movement of the shaft connected to the piston in and out of the cylinder-piston unit, it is exposed to possible contamination of the mixture contained therein.

[0007] This type of ventilator only approximately controls the amount (volume) of ventilation gas actually delivered to the patient because it performs very precise control of the pressure of the ventilation gas delivered to the patient, which is a value that conforms to physiological respiratory activity.

[0008] In other conventional ventilators, the measurement of the volume of ventilation gas relies solely on volume measurement / mass type sensors, which may be troubled by the time drift phenomenon and require their regular calibration. These sensors usually indirectly measure the volume of the ventilation gas delivered based on the measurement of the temperature change of an object that hits the flow of the ventilation gas that the patient inhales or exhales, thereby causing a problem of a certain degree of "physiological" inaccuracy in the measurement of the volume. Other more advanced ventilators utilize the Venturi effect and use a single sensor close to the patient's airway to measure the pressure, flow rate, and volume of the ventilation gas delivered to the patient. Even these ventilators cannot avoid the need for regular calibration. Finally, the aforementioned sensors may have different characteristics and sensitivities depending on the volume to be measured (for example, whether it is used in a ventilator for use in children), which does not make the applications when using this device very wide.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0010] Therefore, there is a need to improve the technical situation in the field of assisted ventilation. The main object of the present invention is to control both the pressure and volume of the gas delivered to the patient in an easy, more accurate and reliable way compared to conventional ventilators. The present invention provides a lung ventilator that can be controlled in a reliable manner.

[0011] Another object of the present invention is to provide a lung ventilator with reduced consumption and reduced overall dimensions compared to conventional ventilators.

[0012] A further object of the present invention is to provide a lung ventilator that is safer than conventional ventilators with respect to the contamination of the gas circulating inside the lung ventilator.

[0013] In particular, the object of the present invention is to provide an operating method for such a lung ventilator that is easy to implement.

Means for Solving the Problems

[0014] A specific object of the present invention is a lung ventilator configured to deliver a desired volume of ventilation gas at a desired pressure to a patient for each respiratory activity, the lung ventilator having a ventilation outlet configured to be in fluid communication with the patient's airway and an exhaust outlet in communication with the outside of the lung ventilator, the lung ventilator comprising at least one adjustment circuit, the at least one adjustment circuit comprising - a cylinder-piston unit having a cylinder and a piston, - an operating chamber having an inlet and an outlet, the inlet of the operating chamber being configured to selectively receive a first gas under pressure, the outlet of the operating chamber being in fluid communication with the exhaust outlet, the operating chamber - a ventilation chamber having an inlet and an outlet, the inlet of the ventilation chamber being configured to selectively receive a pressurized ventilation gas provided to the patient, the outlet of the ventilation chamber being in fluid communication with the ventilation outlet of the lung ventilator, the ventilation chamber A cylinder-piston unit that defines - At least one device for regulating the flow entering the working chamber and at least one device for regulating the flow exiting the working chamber, at least one device for regulating the flow entering the ventilation chamber and at least one device for regulating the flow exiting the ventilation chamber, - At least one pressure detection device configured to detect the pressure of the first gas in the working chamber during use, and another pressure detection device configured to detect the pressure of the ventilation gas in the ventilation chamber during use, - One position detector configured to detect the position of the piston in the cylinder, - One acquisition and processing unit operably connected to the position detector, each device for regulating the flow, and each pressure detection device, the acquisition and processing unit being - Acquiring and processing input signals regarding the position of the piston in the cylinder, the pressure of the first gas in the working chamber, and the pressure of the ventilation gas in the ventilation chamber, Based on the position of the piston in the cylinder, the pressure of the first gas in the working chamber, and the pressure of the ventilation gas in the ventilation chamber, such that a certain amount of ventilation gas corresponding to at least the desired volume enters the ventilation chamber and the desired volume of ventilation gas exits the ventilation chamber towards the ventilation outlet at the desired pressure, an output signal for controlling the opening and closing of each device for regulating the flow into and out of the working chamber and the opening and closing of each device for regulating the flow into and out of the ventilation chamber is provided, the acquisition and processing unit A lung ventilation device having

[0015] According to another aspect of the present invention, the piston may be a magnetized piston configured to move within the cylinder due to the pressure difference between the first gas in the working chamber and the ventilation gas in the ventilation chamber.

[0016] According to a further aspect of the present invention, the position detector may be fixedly mounted externally to the cylinder and may be configured to magnetically detect the position of the piston within the cylinder.

[0017] According to an additional aspect of the present invention, the lung ventilation device may comprise at least one first inlet configured to be arranged in fluid communication with a source of a first gas under pressure, the source may be a main source external to the lung ventilation device, and the inlet of the working chamber may be configured to be selectively arranged in fluid communication with the first inlet of the lung ventilation device for selectively receiving the first gas under pressure.

[0018] According to another aspect of the present invention, the lung ventilation device may have one second inlet and comprise at least one mixing circuit, the at least one mixing circuit comprising - one mixing chamber, and - a first inlet within the mixing chamber, the first inlet of the mixing chamber being in fluid communication with the first inlet of the lung ventilation device and being configured to receive the first gas under pressure when provided by the main source, - a second inlet within the mixing chamber, the second inlet of the mixing chamber being in fluid communication with the second inlet of the lung ventilation device and being configured to receive a second gas under pressure, - a first outlet of the mixing chamber in fluid communication with the inlet of the ventilation chamber and the at least one mixing circuit is operably controlled by an acquisition and processing unit and is configured to mix the first gas under pressure and the second gas under pressure therebetween, thereby obtaining a ventilation gas.

[0019] According to a further aspect of the present invention, the lung ventilation device may comprise one auxiliary circuit for supplying a first gas under pressure, the auxiliary circuit comprising - one pressurized storage bank of the first gas under pressure, and - a first outlet in fluid communication with the storage bank on one side and selectively in fluid communication with the inlet of the working chamber on the other side comprising, the first outlet of the auxiliary circuit being operably controlled by the acquisition and processing unit, and being closed when the main source of the first gas under pressure is connected to the first inlet or opened when the main source of the first gas under pressure is disconnected from the first inlet.

[0020] According to an additional aspect of the invention, the mixing circuit may comprise a third inlet in the mixing chamber, and the auxiliary circuit for supplying the first gas under pressure may comprise at least one second outlet that is in fluid communication with the storage bank on one side and with the third inlet of the mixing circuit on the other side, the second outlet being operably controlled by the acquisition and processing unit and being closed when the main source of the first gas under pressure is connected to the first inlet or opened when the main source of the first gas under pressure is disconnected from the first inlet, so that the first gas under pressure in the storage bank may be supplied into the mixing chamber.

[0021] According to another aspect of the invention, the acquisition and processing unit may comprise at least two electronic systems that communicate with each other, and the programmable electronic system is configured to implement hardware and control redundancy.

[0022] The object of the invention is also a method for delivering a desired volume of ventilation gas at a desired pressure via the lung ventilation device disclosed above, the method comprising the following operating steps: A. Placing the lung ventilation device according to any of the preceding claims; and B. Fluidly connecting the inlet (31) of the working chamber (3) to the first gas under pressure and the inlet (41) of the ventilation chamber (4) to the ventilation gas under pressure; and C. Supplying a certain amount of ventilation gas to the ventilation chamber (4) such that the volume occupied by the ventilation gas in the ventilation chamber (4) is at least equivalent to or greater than the desired volume (Vd). D. Delivering at least a desired volume (Vd) of ventilation gas within the ventilation chamber (4) towards the ventilation outlet (11) of the lung ventilation device (1) at a desired pressure (Pd); A method comprising the above steps.

[0023] According to another aspect of the present invention, steps C and D may be sequentially and periodically repeated, for example, in each respiratory activity of a patient connected to the lung ventilation device described above.

[0024] According to another aspect of the present invention, step C is performed via an acquisition and processing unit: C.1. Acquiring and processing, via a position detector, an input signal regarding the position of the piston within the cylinder; and C.2. Optionally, providing an output signal for adjusting the pressure of the first gas within the working chamber and the pressure of the ventilation gas within the ventilation chamber via controlled opening and closing of respective devices for adjusting inflow and outflow, thereby obtaining the movement of the piston within the cylinder until the volume of the ventilation chamber becomes at least equal to the desired volume. It may include the above steps.

[0025] According to a further aspect of the present invention, step D: D.1. Monitoring the position of the piston within the cylinder via a position detector; and D.2. Optionally, adjusting the pressure of the first gas within the working chamber and the pressure of the ventilation gas within the ventilation chamber via controlled opening and closing of respective devices for adjusting inflow and outflow, thereby obtaining the movement of the piston within the cylinder until the volume of the ventilation chamber decreases to an amount equal to the desired volume. It may include the above steps.

[0026] According to an additional aspect of the present invention, the pressure difference between the first gas and the ventilation gas is optionally constant, and step C.2 or step D.2 each cause the acquisition and processing unit to control a device for regulating the flow entering and leaving each chamber of the cylinder-piston unit so as to cause the movement of the piston within the cylinder.

[0027] According to another aspect of the present invention, the method E.3 may include one step E of adjusting the pressure of the first gas in the working chamber and the pressure of the ventilation gas in the ventilation chamber such that, during step D, the ventilation gas exits the ventilation chamber at a desired pressure.

[0028] According to a further aspect of the present invention, step B - connecting the first inlet of the lung ventilation device to the main external source of the first gas under pressure, opening the device for regulating the flow entering the working chamber, keeping the device for regulating the flow exiting the working chamber closed, connecting the second inlet of the lung ventilation device to the main external source of the second gas under pressure, and opening the device for regulating the flow entering the ventilation chamber while keeping the device for regulating the flow exiting the ventilation chamber closed, or - using the above lung ventilation device, opening the device for regulating the flow entering the working chamber to put the storage group of the auxiliary supply circuit for storing the first gas under pressure into fluid communication with the mixing circuit and the working chamber, keeping the device for regulating the flow exiting the working chamber closed, opening the device for regulating the flow of the supply auxiliary circuit to put it into fluid communication with the mixing circuit via the third inlet of the mixing circuit, connecting the second inlet of the lung ventilation device to the auxiliary supply source of the second gas under pressure, and opening the device for regulating the flow entering the ventilation chamber while keeping the device for regulating the flow exiting the ventilation chamber closed may be included.

Brief Description of the Drawings

[0029] Here, the present invention will be described, by way of illustration and not limitation, in accordance with its preferred embodiments, with particular reference to the accompanying drawings.

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

[0031] Referring to the accompanying drawings, particularly FIG. 1, a lung ventilation device according to the present invention is indicated by reference numeral 1 and is configured to be in fluid communication with a patient's respiratory system (where FIG. 1 schematically represents a ventilation mask), and has one ventilation outlet 11 for delivering one ventilation gas toward the patient, and is in fluid communication with the outside of the lung ventilation device and is also configured to be in fluid communication with the patient's respiratory system, for example, via an exhaust inlet 14 of the lung ventilation device 1 and an appropriate exhaust circuit 9. Note that it includes one exhaust outlet 12.

[0032] The lung ventilation device 1 according to the present invention advantageously includes at least one adjustment circuit 2 configured to adjust the volume and pressure of the ventilation gas provided to the patient in each respiratory activity. The adjustment circuit 2 includes a cylinder-piston unit 21 having a cylinder 211 and a piston 212 that define an operating chamber 3 having an inlet 31 and an outlet 32, and a ventilation chamber 4 having an inlet 41 and an outlet 42 (see particularly FIG. 2).

[0033] As will be described below, the inlet 31 of the operating chamber 3 is configured to selectively receive a first gas under pressure, while the outlet 32 of the operating chamber 3 is in fluid communication with the exhaust outlet 12 of the lung ventilation device 1.

[0034] The inlet 41 of the ventilation chamber 4 is configured to selectively receive the pressurized ventilation gas delivered to the patient, obtained within the lung ventilation device, in the manner described below, and the outlet 42 of the ventilation chamber 4 is optionally in fluid communication with the ventilation outlet 11 of the lung ventilation device 1 via a suitable ventilation circuit, as shown in FIG. 1.

[0035] The adjustment circuit 2 of the lung ventilation device 1 of the present invention also comprises at least one device 22 for adjusting the flow entering the working chamber 3, at least one device 23 for adjusting the flow exiting the working chamber 3, at least one device 24 for adjusting the flow entering the ventilation chamber 4, and at least one device 25 for adjusting the flow exiting the ventilation chamber 4.

[0036] According to a particularly preferred embodiment of the present invention, the device 22 for adjusting the flow entering the working chamber 3 and the device 23 for adjusting the flow exiting the working chamber 3 comprise proportional two-way control valves. Furthermore, according to a particularly preferred embodiment of the present invention, the device 24 for adjusting the flow entering the ventilation chamber 4 comprises at least one on-off control valve, and the device 25 for adjusting the flow exiting the ventilation chamber 4 comprises at least one proportional flow control valve. Between the device 24 for adjusting the flow entering the ventilation chamber 4 and the inlet 41 of the ventilation chamber 4, and between the outlet 42 of the ventilation chamber 4 and the device 25 for adjusting the flow exiting the ventilation chamber 4, the adjustment circuit 2 also comprises a one-way valve 26, which enables the unidirectionality of the ventilation gas towards the ventilation chamber 4 and the ventilation gas from there towards the outlet 11 of the lung ventilation device 1.

[0037] According to the present invention, the adjustment circuit 2 of the lung ventilation device 1 also comprises at least one pressure detection device 27 in the working chamber 3 and a pressure detection device 28 in the ventilation chamber 4. The pressure detection device 27 in the working chamber 3 is configured to detect the pressure value of the first gas, either continuously or stepwise, for example at a predetermined point in time as required. On the other hand, the pressure detection device 28 in the ventilation chamber 4 is configured to detect the pressure value of the ventilation gas, either continuously or stepwise, for example at a predetermined point in time as required.

[0038] According to a particularly advantageous aspect of the present invention, the adjustment circuit 2 of the lung ventilation device 1 of the present invention also comprises a position detector 29 configured to detect the position of the piston 212 in the cylinder 211 with respect to a reference, for example with respect to the central cross-section of the cylinder or with respect to its end cross-section (which coincides with the bottom or top of the cylinder shown in FIG. 2, for example).

[0039] The lung ventilation device 1 of the present invention also comprises, for example, an acquisition and processing unit 6 having at least two programmable electronic systems communicating with each other. This acquisition and processing unit 6 implements hardware and control redundancy to ensure the safety and operation of the lung ventilation device 1 even in the event of a failure of one or the other of these programmable electronic systems. Such an acquisition and processing unit 6 is operably connected to the position detector 29, each device (22, 23, 24, 25) for regulating the flow in the working chamber 3 and the ventilation chamber 4 of the cylinder-piston unit 21, and each pressure detection device 27 and 28.

[0040] The acquisition and processing unit 6 advantageously acquires and processes appropriate input signals regarding the position of the piston 212 in the cylinder 211, the pressure value of the first gas in the working chamber 3, and the pressure value of the ventilation gas in the ventilation chamber 4, and based on the position of the piston 212 in the cylinder 211 and the pressure values of the gases in the working chamber 3 and the ventilation chamber 4, it is configured to send appropriate output signals for controlling the opening and closing of each device (22, 23) for regulating the flow entering and leaving the working chamber 3 and each device (24, 25) for regulating the flow entering and leaving the ventilation chamber 4. Therefore, a certain amount of ventilation gas corresponding to at least the desired volume Vd enters the ventilation chamber 4, and then the ventilation gas of the desired volume Vd exits the ventilation chamber 4 towards the ventilation outlet 11 at the desired pressure Pd.

[0041] In particular, the desired volume Vd is automatically determined by the acquisition and processing unit 6 or manually set by a medical operator, and corresponds to the tidal volume stored in the acquisition and processing unit 6 of the lung ventilator 1 via any suitable method, for example, a keyboard or touch screen or other input / output device that may be connected to the lung ventilator 1, or other devices incorporated therein. The desired pressure Pd is automatically determined by the acquisition and processing unit 6 or manually set by a medical operator, and corresponds to a pressure value within a safe range that conforms to the patient's respiratory activity and is stored in the acquisition and processing unit 6 of the lung ventilator 1 via any suitable method, for example, the above-mentioned keyboard or touch screen or other input / output device that may be connected to the lung ventilator 1, or other devices incorporated therein.

[0042] According to a particularly advantageous aspect of the invention, the piston 212 of the cylinder-piston unit 2 is a magnetized piston configured to move in the cylinder 211, for example along an appropriate guide in the cylinder 211, due to the pressure difference between the pressure value of the first gas in the working chamber 3 and the pressure value of the ventilation gas in the ventilation chamber 4. Further, the position detector 29 is fixed outside the cylinder 211 and is configured to magnetically detect the position of the piston 212 in the cylinder 211. The configuration of the cylinder-piston unit 2, in which the piston does not operate mechanically via a shaft connected to the cylinder-piston unit 2 as in the prior art, but instead slides on an appropriate guide due to the pressure difference between the two chambers, is advantageous over the prior art considering that the cylinder is closed (except for the gas inlets and outlets of the working chamber and the ventilation chamber), and thus the gas circulating inside it is less likely to be contaminated from the outside. Moreover, as will be better explained below, the configuration of the cylinder-piston unit 2 enables the accurate desired volume Vd of the ventilation gas (the single ventilation volume set by the operator) to be stored in the ventilation chamber with a single movement of the piston 212.

[0043] According to a preferred embodiment of the invention, the lung ventilation device 1 comprises a first inlet 10 configured to be arranged in fluid communication with a source of the first gas under pressure. The source of the first gas under pressure is, in this case, for example, a main external source of the lung ventilation device 1 forming part of the distribution system of a hospital / medical facility where the lung ventilation device 1 according to the invention can be installed, and the inlet 31 of the working chamber 3 is selectively in fluid communication with the first inlet 10 and is configured to selectively receive the first gas under pressure via a device 22 for regulating the incoming flow.

[0044] The lung ventilation device 1 of the invention also has a second inlet 13 configured to receive from the outside a second gas under pressure, for example delivered by a main external source of the lung ventilation device 1, forming part of the distribution system of a hospital / medical facility where the lung ventilation device 1 can be installed.

[0045] The lung ventilation device 1 includes a mixing circuit 7 (Fig. 3) having a mixing chamber 70, a first inlet 71 within the mixing chamber 70, a second inlet 72 within the mixing chamber 70, and one outlet 73 from the mixing chamber. The first inlet 71 of the mixing chamber 70 is in fluid communication with the first inlet 10 of the lung ventilation device 1 and is configured to receive a first gas under pressure when delivered by a main supply source. The second inlet 72 of the mixing chamber 70 is in fluid communication with the second inlet 13 of the lung ventilation device 1 and is configured to receive a second gas under pressure when delivered by respective main supply sources. The outlet 73 of the mixing chamber is in fluid communication with the inlet 41 of the ventilation chamber 4 of the cylinder-piston unit 21 of the regulation circuit 2.

[0046] The mixing circuit 7 is configured to mix a first gas under pressure and a second gas under pressure with each other in the mixing chamber 70, thereby obtaining a ventilation gas. Advantageously, the first gas under pressure includes medical air or a mixed gas of helium and oxygen (e.g., heliox), and the second gas under pressure includes oxygen.

[0047] Downstream of the outlet 73 of the mixing chamber, so that the ventilation gas sent to the ventilation chamber 4 has an accurate pressure and humidity level, the mixing circuit 7 according to a preferred embodiment of the present invention also includes one device 74 for adjusting the pressure, e.g., a valve controlled by an acquisition and processing unit 6 and detecting and adjusting the pressure of the ventilation gas directed towards the ventilation chamber 4, which is in fluid communication with the exhaust outlet 12 of the lung ventilation device 1, and optionally, a dehumidifying filter 75.

[0048] According to another particularly advantageous aspect, the lung ventilation device 1 of the present invention also comprises an auxiliary circuit 8 for supplying a first gas under pressure (Figure 4). The auxiliary circuit 8 comprises a pressurized storage group 80 for the first gas and a first outlet 81. The first outlet 81 of the auxiliary circuit 8 is in fluid communication on one side with the first gas under pressure stored in the storage group 80 and on the other side, via a device 22 for regulating the flow entering the working chamber 3 controlled by the acquisition and processing unit 6, with the inlet 31 of the working chamber 3 selectively in fluid communication.

[0049] According to a preferred embodiment of the present invention, the pressurized storage group 80 for the first gas comprises a membrane pump 801 controlled by a motor unit 802 and configured to take in air from the outside. The storage unit 80 also comprises a tank 803 downstream of the membrane pump and configured to store the air taken in by the membrane pump, and optionally also comprises a filter 804 connected upstream of the membrane pump 801 and configured to filter the air entering from the outside before being sucked in by the membrane pump. Thus, the first outlet 81 of the auxiliary circuit 8 is optionally in fluid communication with the tank 803 via a one-way valve 26. For example, if the main supply source of the first gas under pressure is cut off from its first inlet 10 or in case of some failure and the first gas under pressure (i.e., medical air) does not enter the lung ventilation device 1 at its first inlet 10, the auxiliary circuit 8 is configured to supply the first gas under pressure (i.e., optionally filtered and pressurized air).

[0050] According to another advantageous aspect of the present invention, the mixing circuit 7 also comprises a third inlet 76 within the mixing chamber 70, and the auxiliary circuit 8 for supplying the first pressurized gas comprises at least a second outlet 82. The second outlet 82 of the auxiliary circuit 8 is, on the one hand, in fluid communication with the tank 803 of the storage group 80, and on the other hand, a device 83 optionally included in the auxiliary circuit 8 between the tank 803 and the second outlet 82 for regulating the flow, optionally by a two-way valve, is selectively in fluid communication with the third inlet 76 of the mixing circuit 7. The opening and closing of the second outlet 82 is operably controlled by the acquisition and processing unit 6. Thereby, when the first pressurized gas enters the lung ventilator 1 at its first inlet 10, the second outlet 82 of the auxiliary circuit 8 is closed, and instead, when the first gas under pressure does not enter the lung ventilator 1 at its first inlet 10 (if provided, by switching the two-way valve 83 by the acquisition and processing unit 6), it is opened. For example, because the main supply source of the first gas under pressure is disconnected or exhausted from its first inlet 10. In this case, the first gas under pressure contained in the tank 803 can flow into the mixing chamber 70 of the mixing circuit, and can also flow into the working chamber 31 if the flow entering the regulating device 22 is in the correct position (i.e., open).

[0051] With this configuration of the auxiliary circuit 8, for example, by disconnecting the first inlet 10 and the second inlet 13 of the lung ventilator 1 from the distribution network of the hospital / medical facility in which it is installed and operating the membrane pump 801, and connecting the second inlet 13 of the lung ventilator to an auxiliary source of medical oxygen, such as an oxygen cylinder, it is completely clear that the lung ventilator 1 of the present invention can be easily used as a portable lung ventilator. In this case, a person skilled in the art will understand without any problem that each component of the lung ventilator 1 that requires power supply for its operation, such as the acquisition and processing unit 6, etc., may not only be powered by connecting the lung ventilator 1 to the power distribution network of the hospital / medical facility where the ventilator is installed, but also, optionally, be powered by a rechargeable battery incorporated in the lung ventilator 1 according to the present invention. In this regard, according to a preferred embodiment of the present invention, the lung ventilator 1 is provided with a pair of rechargeable batteries, each battery being electrically connected to each component of the lung ventilator 1 that requires power supply for its operation, and as an alternative means, when the ventilator 1 is not powered by the power distribution network of the structure, it can be operated to prevent the malfunction of the battery from impairing the operation of the lung ventilator.

[0052] According to another advantageous aspect of the present invention, the lung ventilator 1 of the present invention also comprises a bypass circuit 200 for the ventilation gas, which is connected between the inlet and the outlet of the ventilation chamber 4 of the cylinder-piston unit 2, in particular, between upstream of the regulating device 24 and downstream of the regulating device 25, and is also connected to the exhaust outlet 12 of the lung ventilator 1 at the regulating device 25. Such a bypass circuit 200 is operably connected to the acquisition and processing unit 6 and is configured to provide an alternative passage for the ventilation gas to the regulating circuit 2 so as to enable ventilation of the patient by means of the so-called high-flow technique, and the flow rate of the ventilation gas is above a certain threshold value, optionally above 80 liters per minute (l / minute). According to a preferred embodiment of the present invention, the bypass circuit 200 comprises at least one proportional flow control valve.

[0053] The above-described lung ventilation device 1 can be used to supply ventilation gas of a desired volume Vd at a desired pressure Pd in accordance with a method which is also an object of the present invention. Such a method includes the following operating steps: A. Placing the above-described lung ventilation device; and B. Fluidly connecting the first inlet 31 of the working chamber 3 to a first gas under pressure and the inlet 41 of the ventilation chamber 4 to a ventilation gas under pressure; and C. Supplying a certain amount of ventilation gas into the ventilation chamber 4 such that the volume occupied by the ventilation gas in the ventilation chamber 4 is at least equivalent to the desired volume Vd or greater than the desired volume Vd; and then D. Delivering at least the desired volume Vd of the ventilation gas in the ventilation chamber 4 towards the ventilation outlet 11 of the lung ventilation device 1 at a preset desired pressure Pd are included.

[0054] According to a preferred embodiment of the present invention, steps C and D of the above method are sequentially (step C before step D) and periodically repeated, for example, for each respiratory activity of a patient connected to the ventilation device. More specifically, each delivery of the desired volume Vd of the ventilation gas in step D corresponds, in time, to each inspiration of the patient.

[0055] Returning to the steps of the method of the present invention, step B then - Fluidly connecting the first inlet 10 of the lung ventilation device 1 to a main supply source of a first gas under pressure, opening a device 22 for regulating the flow entering the working chamber 3, keeping a device 23 for regulating the flow exiting the working chamber 3 closed, fluidly connecting the second inlet 13 of the lung ventilation device 1 to a main supply source of a second gas under pressure, and opening a device 24 for regulating the flow entering the ventilation chamber 4 while keeping a device 25 for regulating the flow exiting the ventilation chamber 4 closed, or - Open the storage group (in particular the tank 803) of the supply assistance circuit 8 containing the first gas under pressure, open the device 22 for regulating the flow entering the working chamber 3, and keep the device 23 for regulating the flow exiting the working chamber 3 closed, thereby opening the working chamber 3 and the device 83 for regulating the flow upstream of the second outlet 82, fluidly connecting both to the mixing circuit 7 via its third inlet 76, fluidly connecting the second inlet 13 of the lung ventilation device 13 to an auxiliary supply source of the second gas under pressure, such as a tank, and opening the device 24 for regulating the flow entering the ventilation chamber 4 while keeping the device 25 for regulating the flow exiting the ventilation chamber 4 closed It should be noted that it includes the following

[0056] Referring to step C of this method, this is via the acquisition and processing unit 6 C.1 Optionally, continuously or stepwise, acquire and process an input signal regarding the position of the piston 212 in the cylinder 211 via the position detector 29 C.2 If necessary, provide an output signal for regulating the pressure of the first gas in the working chamber 3 and the pressure of the ventilation gas in the ventilation chamber 4 via the controlled opening and closing of the respective devices for regulating the inflow and outflow, thereby obtaining the movement of the piston 212 in the cylinder 211 until the volume of the ventilation chamber 4 is at least equal to the desired volume Vd It includes the following

[0057] As shown, since the shape of the cylinder-piston unit 21 is known in advance and the position of the piston 212 may be detected by the acquisition and processing unit 6 via the position detector 29, the volume in the ventilation chamber 4 can be controlled very precisely. Thus, once the desired volume Vd is known, thanks to the acquisition and processing unit 6, it is easy to determine how much the piston 212 has to move in the cylinder to obtain this effect, and thus how much the pressure between the working chamber 3 and the ventilation chamber 4 has to change

[0058] Referring to step D of the method of the present invention, step D is, via the acquisition and processing unit 6, D.1 Optionally, continuously or stepwise, obtaining and processing an input signal regarding the position of the piston 212 within the cylinder 211 via the position detector 29; D.2 Optionally, providing an output signal for adjusting the pressure of the first gas within the working chamber 3 and the pressure of the ventilation gas within the ventilation chamber 4 via the controlled opening and closing of the respective devices for adjusting the inflow and outflow, thereby obtaining the movement of the piston 212 within the cylinder 211 until the volume of the ventilation chamber 4 decreases to an amount equal to the desired volume Vd; and includes.

[0059] Considering the presence of the magnetized piston 212 and the position detector 28, it is clear that the same matters as above apply regarding the accuracy with which the volume of the measurement chamber can be controlled.

[0060] A person skilled in the art will readily understand that steps C.2 and D.2 require the control of the devices (22, 23, 24, and 25) for adjusting the flow into and out of each chamber of the cylinder-piston unit 21 via the acquisition and processing unit 6, whereby the first gas and the ventilation gas reach the pressures necessary to determine the displacement of the cylinder 212 in the desired direction due to their difference.

[0061] The method of the present invention also includes, in step E, via the acquisition and processing unit 6, E.3 During step D, transmitting an output signal for adjusting the pressure of the first gas within the working chamber 3 and the pressure of the ventilation gas within the ventilation chamber 4 such that the ventilation gas exits the ventilation chamber 4 at the desired pressure Pd. and includes.

[0062] This pressure control includes adjusting the opening and closing of device 25 for regulating the flow exiting ventilation chamber 4 via acquisition and processing unit 6.

[0063] With this configuration of lung ventilator 1 and the above method, it is also possible to use lung ventilator 1 when the patient's demand for ventilation gas is greater than the maximum physical volume that ventilation chamber 4 can have. In fact, by appropriately adjusting the devices (22, 23, 24, and 25) for regulating the flow entering and exiting each chamber of cylinder - piston unit 21, the ventilation gas in ventilation chamber 4 can be compressed to store a larger amount of ventilation gas corresponding to the desired volume Vd required by the patient.

[0064] It is clear that the above - mentioned lung ventilator and its operation method solve the drawbacks shown at the beginning. In fact, with the specific configuration of lung ventilator 1 having magnetized piston 212 that is completely closed inside cylinder 211, position detector 29 outside cylinder 211, and devices (22, 23, 24, 25) for regulating the flow entering and exiting the working chamber and ventilation chamber, both the pressure and volume of the gas delivered to the patient can be controlled in an easier, more accurate, and reliable way than conventional ventilators. Also, due to the specific configuration of piston 212, contamination of the gas circulating inside the lung ventilator from the outside can be avoided. In the cylinder - piston 21 unit, the absence of an external mechanical actuation system for piston 212 further reduces the overall dimensions of lung ventilator 1 and its consumption. The presence of an auxiliary circuit for supplying the first gas enables lung ventilator 1 to be easily carried, and thus can be made portable. Moreover, the pressure inside the working chamber and ventilation chamber can be easily controlled, enabling the use of the lung ventilator of the present invention even when the tidal volume required by the patient is greater than the maximum physical volume that the ventilation chamber 4 of cylinder - piston unit 21 can reach.

[0065] In the foregoing, although the preferred embodiments and modifications of the present invention have been proposed, it should be understood by those skilled in the art that modifications and changes can be made without departing from the relative protection scope defined by the appended claims.

[0066] For example, in the above preferred embodiment, the one-way valve 26 can be replaced with an element equivalent from a technical perspective that enables maintaining the one-way flow of the operating gas and the ventilation gas as described above.

[0067] Furthermore, for example, in the mixing chamber 70 downstream of each of the inlets 71 and 72, respective devices for regulating the flow of the first and second gases can be provided, and these devices are operably connected to the acquisition and processing unit 6, and these devices can be operated manually and automatically to control the mixing of these gases in the ventilation gas.

[0068] Furthermore, the lung ventilation device 1 of the present invention can be configured to be able to introduce additional substances, for example, atomized drugs or sedatives administered to the patient through the respiratory tract, into the mixture of the first and second gases.

Claims

1. A lung ventilation device (1) configured to deliver a ventilation gas of a desired volume (Vd) at a desired pressure (Pd) to a patient for each respiratory activity, the lung ventilation device (1) comprising a ventilation outlet (11) configured to be in fluid communication with the airway of the patient, and an exhaust outlet (12) in communication with the outside of the lung ventilation device (1), the lung ventilation device (1) comprising at least one adjustment circuit (2), the at least one adjustment circuit (2) comprising - a cylinder-piston unit (21) having a cylinder (211) and a piston (212), - an operating chamber (3) having an inlet (31) and an outlet (32), the inlet (31) of the operating chamber (3) being configured to selectively receive a first gas under pressure, the outlet (32) of the operating chamber (3) being in fluid communication with the exhaust outlet (12), the operating chamber (3), - a ventilation chamber (4) having an inlet (41) and an outlet (42), the inlet (41) of the ventilation chamber (4) being configured to selectively receive the ventilation gas under pressure provided to the patient, the outlet (42) of the ventilation chamber (4) being in fluid communication with the ventilation outlet (11) of the lung ventilation device (1), the ventilation chamber (4), defining a cylinder-piston unit (21), - at least one device (22) for regulating the flow entering the operating chamber (3) and at least one device (23) for regulating the flow exiting the operating chamber (3), at least one device (24) for regulating the flow entering the ventilation chamber (4) and at least one device (25) for regulating the flow exiting the ventilation chamber (4), - at least one pressure detection device (27) configured to detect the pressure of the first gas in the operating chamber (3) during use, and another pressure detection device (28) configured to detect the pressure value of the ventilation gas in the ventilation chamber (4) during use, - one position detector (29) configured to detect the position of the piston (212) in the cylinder (211), - One acquisition and processing unit (6) operably connected to the position detector (29), each device (22, 23, 24, 25) for regulating the flow, and each pressure detection device (27, 28), wherein the acquisition and processing unit (6) - Acquires and processes input signals regarding the position of the piston (212) in the cylinder (212), the pressure of the first gas in the working chamber (3), and the pressure of the ventilation gas in the ventilation chamber (4). - At least a certain amount of the ventilation gas corresponding to the desired volume (Vd) enters the ventilation chamber (4), and the ventilation gas of the desired volume (Vd) exits the ventilation chamber (4) toward the ventilation outlet (11) at the desired pressure (Pd). Based on the position of the piston (212) in the cylinder (211), the pressure of the first gas in the working chamber (3), and the pressure of the ventilation gas in the ventilation chamber (4), the opening and closing of each device (22, 23) for regulating the flow into and out of the working chamber (3), and the opening and closing of each device (24, 25) for regulating the flow into and out of the ventilation chamber (4) are controlled to provide an output signal. An acquisition and processing unit (6) configured as A lung ventilation device (1) having. **Claim 2** The lung ventilation device (1) according to claim 1, wherein the piston (212) is a magnetized piston configured to move within the cylinder (211) due to a pressure difference between the first gas in the working chamber (3) and the ventilation gas in the ventilation chamber (4). **Claim 3** The lung ventilation device (1) according to claim 2, wherein the position detector (29) is fixedly external to the cylinder (211) and is configured to magnetically detect the position of the piston (212) within the cylinder (211). **Claim 4** Comprising at least one first inlet (10) configured to be disposed in fluid communication with a source of the first gas under pressure, the source being a main source external to the lung ventilation device (1), and the inlet (31) of the working chamber (3) being configured to be selectively in fluid communication with the first inlet (10) of the lung ventilation device (1) to selectively receive the first gas under pressure. The lung ventilation device (1) according to any one of claims 1 to 3. **Claim 5** having one second inlet (13) and comprising at least one mixing circuit (7), said at least one mixing circuit (7) being - one mixing chamber (70); - a first inlet (71) within said mixing chamber (70), said first inlet (71) of said mixing chamber being in fluid communication with said first inlet (10) of said lung ventilation device (1) and configured to receive said first gas under pressure when provided by said main supply; - a second inlet (72) within said mixing chamber (70), said second inlet (72) of said mixing chamber being in fluid communication with said second inlet (13) of said lung ventilation device (1) and configured to receive a second gas under pressure; - a first outlet (73) of said mixing chamber (70) in fluid communication with said inlet (41) of said ventilation chamber (4); and said at least one mixing circuit (7) being operably controlled by said acquisition and processing unit (6) to mix said first gas under pressure and said second gas under pressure therebetween, thereby obtaining said ventilation gas, the lung ventilation device (1) according to claim 4. **Claim 6** comprising one auxiliary circuit (8) for supplying said first gas under pressure, said auxiliary circuit (8) being - one pressurized storage bank (80) of said first gas under pressure; - a first outlet (81) in fluid communication with said storage bank (80) on one side and selectively in fluid communication with said inlet (31) of said working chamber (3) on the other side; and said first outlet (81) of said auxiliary circuit (8) being operably controlled by said acquisition and processing unit (6) and configured to be closed when said main supply of said first gas under pressure is connected to said first inlet (10) or to be opened when said main supply of said first gas under pressure is disconnected from said first inlet (10), the lung ventilation device (1) according to any one of claims 1 to 5. **Claim 7** The mixing circuit (7) comprises a third inlet (76) in the mixing chamber (70), and the auxiliary circuit (8) for supplying the first gas under pressure is in fluid communication with the storage group (80) on one side and with the third inlet (76) of the mixing circuit (7) on the other side, and comprises at least one second outlet (82), the second outlet (82) being operably controlled by the acquisition and processing unit (6), the main source of the first gas under pressure being closed when connected to the first inlet (10) so that the first gas under pressure in the storage group (80) is supplied into the mixing chamber (70), or being configured to open when the main source of the first gas under pressure is disconnected from the first inlet (10). The lung ventilation device (1) according to claim 5 or 6.

8. The acquisition and processing unit (6) comprises at least two programmable electronic systems that communicate with each other, and the programmable electronic systems are configured to implement hardware and control redundancy. The lung ventilation device (1) according to any one of claims 1 to 7.

9. A method for delivering a ventilation gas of a desired volume (Vd) at a desired pressure (Pd) via the lung ventilation device (1) according to any one of claims 1 to 8, the method comprising the following operating steps: A. Placing the lung ventilation device (1) according to any one of claims 1 to 8; B. Fluidly connecting the inlet (31) of the working chamber (3) to the first gas under pressure and the inlet (41) of the ventilation chamber (4) to the ventilation gas under pressure; C. Supplying a certain amount of the ventilation gas to the ventilation chamber (4) such that the volume occupied by the ventilation gas in the ventilation chamber (4) is at least equivalent to or greater than the desired volume (Vd); D. Delivering at least the desired volume (Vd) of the ventilation gas in the ventilation chamber (4) towards the ventilation outlet (11) of the lung ventilation device (1) at the desired pressure (Pd). A method comprising the above steps.

10. The method according to claim 9 or 10, wherein steps C and D are sequentially and periodically repeated.

11. Step C is via the acquisition and processing unit (6). C.1 Obtaining and processing an input signal regarding the position of the piston (212) within the cylinder (211) via the position detector (29); C.2 Providing an output signal for adjusting the pressure of the first gas within the working chamber (3) and the pressure of the ventilation gas within the ventilation chamber (4) via controlled opening and closing of respective devices (22, 23, 24, 25) for adjusting inflow and outflow, thereby obtaining the movement of the piston (212) within the cylinder (211) until the volume of the ventilation chamber (4) becomes at least equal to the desired volume (Vd); The method according to claim 9 or 10, comprising the steps above.

12. Said step D comprises: D.1 Monitoring the position of the piston (212) within the cylinder (211) via the position detector (29); D.2 Adjusting the pressure of the first gas within the working chamber (3) and the pressure of the ventilation gas within the ventilation chamber (4) via controlled opening and closing of respective devices (22, 23, 24, 25) for adjusting inflow and outflow, thereby obtaining the movement of the piston (212) within the cylinder (211) until the volume of the ventilation chamber (4) decreases to an amount equal to the desired volume (Vd); The method according to any one of claims 9 to 11, comprising the steps above.

13. The pressure difference between the first gas and the ventilation gas is optionally constant, and step C.2 or step D.2 each comprises controlling the devices (22, 23, 24, 25) for adjusting the flow in and out of each chamber of the cylinder-piston unit (21) by the acquisition and processing unit (6) so as to cause the movement of the piston (212) within the cylinder (211). The method according to claim 11 or 12.

14. E.3 Adjusting the pressure of the first gas within the working chamber (3) and the pressure of the ventilation gas within the ventilation chamber (4) such that the ventilation gas exits the ventilation chamber (4) at the desired pressure (Pd) during said step D. The method according to any one of claims 9 to 13, comprising one step E as above.

15. Said step B comprises: - Opening the device (22) for regulating the flow entering the working chamber (3) by fluidly connecting the first inlet (10) of the lung ventilation device (1) to the main external source of the first gas under pressure, keeping the device (23) for regulating the flow exiting the working chamber (3) closed, fluidly connecting the second inlet (13) of the lung ventilation device (1) to the main external source of the second gas under pressure, and opening the device (24) for regulating the flow entering the ventilation chamber (4) while keeping the device (25) for regulating the flow exiting the ventilation chamber (4) closed, or - Using the lung ventilation device (1) according to claim 7, fluidly connecting the storage group (80) of the auxiliary supply circuit (8) for storing the first gas under pressure to the mixing circuit (7) and the working chamber (3) by opening the device (22) for regulating the flow entering the working chamber (3), keeping the device (23) for regulating the flow exiting the working chamber (3) closed, fluidly connecting the mixing circuit (7) through the third inlet (76) of the mixing circuit (7) by opening the device (83) for regulating the flow of the supply auxiliary circuit (8), fluidly connecting the second inlet (13) of the lung ventilation device (1) to the auxiliary supply source of the second gas under pressure, and opening the (24) for regulating the flow entering the ventilation chamber (4) while keeping the device (25) for regulating the flow exiting the ventilation chamber (4) closed The method according to any one of claims 9 to 14, comprising.

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