WO2021191642A2

WO2021191642A2 - Ventilator system and three-way valve for a ventilator system

Info

Publication number: WO2021191642A2
Application number: PCT/HU2020/050013
Authority: WO
Inventors: Miklós KOZLOVSZKY; Tivadar Gábor GARAMVÖLGYI; Bence Takács; Péter Galambos; Tamás Péter Haidegger
Original assignee: Medicor Elektronika Zrt.
Priority date: 2020-03-26
Filing date: 2020-04-23
Publication date: 2021-09-30
Also published as: WO2021191642A3; HU231328B1; HUP2000116A1

Abstract

The invention relates to a ventilator system comprising an inspiratory gas supply subsystem for supplying gas at a pressure above ambient atmospheric pressure, a ventilator module connectable therewith through a gas supply pipe system allowing gas communication, and comprising a gas discharge pipe system for discharging gas from the ventilator module, characterised by comprising a plurality of ventilator modules each having an inlet side and an outlet side, the gas supply pipe system comprising an inspiratory bus having a gas inlet segment and comprising a plurality of inspiratory pipes which are connected directly or indirectly to the inspiratory bus downstream of the gas inlet segment, each inspiratory pipe is connected to or connectable to the inlet side of one of the plurality of ventilator modules, and the inspiratory gas supply subsystem is connected to the gas inlet segment of the inspiratory bus for delivering inspiratory gas at a first pressure higher than the ambient atmospheric pressure into the gas inlet segment, the gas discharge pipe system comprising an expiratory bus having a gas outlet segment and comprising a plurality of expiratory pipes which are connected directly or indirectly to the expiratory bus upstream of the gas outlet segment, and each expiratory pipe is connectable to the outlet side of one of the plurality of ventilator modules, the ventilator system further comprising an expiratory gas discharge subsystem being in gas communication with the gas outlet segment of the expiratory bus for producing a second pressure lower than the ambient atmospheric pressure in the gas outlet segment.

Description

VENTILATOR SYSTEM AND THREE-WAY VALVE FOR A VENTILATOR SYSTEM

The invention relates to a ventilator system comprising an inspiratory gas supply subsystem for providing inspiratory gas having a pressure greater than atmospheric pressure, a ventilator module connectable to the inspiratory gas supply subsystem via an inspiratory pipe system and an expiratory pipe system for removing gas from the ventilator module.

The invention further relates to a three-way valve for connecting the gas supply side, the gas exhaustion side and the patient side within the mass ventilator system.

Effective treatment of epidemics causing acute respiratory problems (ARDS) (e.g. COVID-19) and SARS, MERS, which previously caused minor epidemics, is only possible with a significant medical equipment and efficient medical care. One of the keys to treating acute breathing problems is continuous ventilation of the patient. Current medical practice implements ventilation with dedicated ventilation devices for the ventilation of a patient, the effectiveness of which, in the event of a large number of acute patients due to pandemics, poses many problems in terms of hardware quantity, capacity, availability, manageability, and deployability.

It is an object of the present invention to provide a system and method which overcomes the disadvantages of prior art single-person ventilators. In particular, it is an object of the present invention to provide a system and method for enabling effective ventilation of a large number of patients (mass ventilation).

The invention is based on the recognition that the joint ventilation of several patients can be achieved if the patients are connected to a modular or monolithically designed central ventilator system. The system can be designed in a pre-built or ad- hoc way (in medical / non-medical institutions, e.g., hospital wards, sports fields, gyms, etc.). In the ventilator system designed for mass ventilation, the inhalation and expiratory gases are produced (prepared) and treated in a collective manner, so that these gasses can preferably be managed uniformly (filtration, pressure and volumetric flow rate control, possibly temperature and humidity control, etc.). During inhalation and exhalation, the air (in one or more stages) can preferably be filtered in both directions, thus effectively reducing the risk of infection.

Based on the above recognition, the invention relates to a ventilator system according to claim 1 .

The invention further relates to a three-way valve according to claim 13 for use in the ventilator system according to the invention.

Some preferred embodiments of the invention are defined in the dependent claims.

Further details of the invention will be described with reference to the accompanying drawings. In the drawings:

Fig. 1 is a schematic block diagram of a preferred embodiment of the system according to the invention, a

Fig. 2 is a block diagram of a preferred modular embodiment of the system according to the invention,

Fig. 3 is a schematic block diagram of an exemplary ventilator module,

Fig. 3a is a cross-sectional view of an exemplary valve control, and

Fig. 4 is a block diagram illustrating the connection of multiple system modules of the embodiment of Fig. 2.

Fig. 1 is a schematic block diagram of a preferred embodiment of a mass ventilator system 10 in accordance with the present invention. The ventilator system 10 can be logically divided into several zones. The part designated by "Zone A" comprises an inspiratory gas supply subsystem 20 for the production of inspiratory gas having a pressure greater than atmospheric pressure. The part designated by "Zone BB" includes an inspiratory pipe system 40 that provides gas connection between the inspiratory gas supply subsystem 20 and a plurality of ventilator modules 30 in the part indicated with "Zone P" in Fig. 1 . The gas supply pipe system comprises an inspiratory bus 42 and a plurality of inspiratory pipes 44 corresponding to the number of ventilator modules 30. Inspiratory bus 42 refers to a gas delivery tube, the term "bus" refers to the delivery of inspiratory gas to a plurality (up to hundreds) of points of use through this gas delivery tube. Accordingly, the cross section of the inspiratory bus 42 is preferably larger than the cross sections of each of the inspiratory pipes 44. The inspiratory bus 42 has a gas inlet segment 46 (see Fig. 2) and is connected to the inspiratory gas supply subsystem 20 through the gas inlet segment 46 such that the subsystem 20 is capable of delivering inspiratory gas at a pressure greater than ambient atmospheric pressure to the gas inlet segment 46. This means that if, for example, in the subsystem 20, a motorized fan produces an inspiratory gas at a pressure higher than atmospheric pressure, then the inspiratory bus 42 is connected to the discharge side of the fan, i.e. not to the suction side. The same is true for other embodiments in which the subsystem 20 includes a device with a suction and a discharge side, such as a gas compressor. Of course, an embodiment is conceivable in which the subsystem 20 does not have a suction side, for example if the subsystem 20 comprises a pressurized cylinder containing inspiratory gas, possibly having an increased concentration of oxygen, and supplying inspiratory gas above atmospheric pressure consists in progressively introducing the contents of the cylinder into the gas inlet segment 46 of the inspiratory bus 42.

Preferably, one or more air purifiers are provided in the subsystem 20 to filter the supplied inspiratory gas as much as possible from pathogens and other contaminants. For example, a FIEPA (Fligh-efficiency particulate air) filter or other fine particle filter, activated carbon filter, antibacterial filter, etc. can be used. Preferably, at least one air purifying device is located in a region of the subsystem 20 connected to the gas inlet segment 46 of the inspiratory bus 42 to allow already purified inspiratory gas to enter the gas inlet segment 46. Of course, the air purifier can also be located in the inspiratory bus 42, but this makes it difficult to replace the filter in the air purifier, for example.

The plurality of inspiratory pipes 44 are connected to the inspiratory bus 42 downstream of the gas inlet segment 46 of the inspiratory bus 42, either directly or indirectly, for example via one or more sub-buses 48, such an arrangement being shown in Figs. 2 and 3. The term connected downstream of the gas inlet segment 46 signifies that the inspiratory pipes 44 are located downstream with respect to the gas flow direction, i.e., the inspiratory gas entering the gas inlet segment 46 from the subsystem 20 flows toward the connection points of the inspiratory pipes 44.

Each of the inspiratory pipes 44 is or can be connected to an inlet side 30a of the ventilator module 30, including the case where the inspiratory pipes 44 are permanently connected to the inlet side 30a of the ventilator module 30, this includes the possibility that the inspiratory pipes 44 are permanently connected to the inlet side 30a of the ventilator module 30 and may even be formed as a single-piece element therewith, accordingly, stating that the inspiratory pipes 44 belong to zone BB can be a purely logical grouping. The inlet side 30a and the outlet side 30b of the ventilator module 30 may also be formed as gas pipes, in which case it is also conceivable that the inspiratory pipes 44 are only nozzles to which the gas pipes of the inlet side 30a of each ventilator module 30 can be connected.

Each of the ventilator modules 30 can be connected to a patient and serves to deliver the inspiratory gas introduced on the inlet side 30a of the ventilator module 30 to the patient's lungs and then to discharge the exhaled gas from the outlet side 30b of the ventilator module 30.

Preferably, personalized ventilation parameters are set for each ventilator module 30 in zone P, which may include setting certain parameters of the inspiratory gas produced by the inspiratory gas supply subsystem 20 (e.g., temperature, humidity), adjusting ventilation parameters (e.g., respiratory rate, inhalation and exhalation time, pressure, volumetric flow rate, shape of a curve describing their time dependence), and preferably the oxygen concentration of the inspiratory gas is also adjusted in zone P, for example from an oxygen cylinder from which oxygen is added to the inspiratory gas introduced through the inlet side 30a.

From the outlet side 30b of the ventilator modules 30, the expiratory gases and the gases not used by the patient flowing through the ventilator module 30 are discharged through a gas discharge pipe system 60 belonging to the "KB zone" in Fig. 1 . For the sake of simplicity these gases are not distinguished from each other, instead these gases are collectively referred to as expiratory (or exhalation) gases.

The gas discharge pipe system 60 comprises an expiratory bus 62 and a plurality of expiratory pipes 64 corresponding to the number of ventilator modules 30. Expiratory bus 62 signifies a gas delivery duct used to collect and collectively transport exhaled gases from points of use, which is indicated by the term "bus". Accordingly, the cross section of the expiratory bus 62 is preferably larger than the cross sections of each of the expiratory pipes 64. The expiratory bus 62 has a gas outlet segment 66 (see, e.g., Fig. 2) and is connected therethrough to the expiratory gas discharge subsystem 80 of "Zone O" in Fig. 1 so that the subsystem 80 is capable of producing a gas pressure lower than the ambient atmospheric pressure in the gas outlet segment 66 and thus to provide a suction effect in the direction of the gas outlet segment 66 inside the expiratory bus 62. This can be accomplished for example by a motorized fan provides a pressure lower than ambient atmospheric pressure (relative vacuum) in the subsystem 80 such that the expiratory bus 62 lies on the suction side of the fan. The same is true for other embodiments in which the subsystem 80 includes a device with a suction side, such as a gas pump.

Preferably, one or more air purifiers are provided in the subsystem 80 to filter the exhaled gas exiting the subsystem 80 from pathogens and other contaminants as much as possible. For example, a HEPA filter or other fine particle filter, activated carbon filter, antibacterial filter, etc. can be used.

The plurality of expiratory pipes 64 are connected to the expiratory bus 62 upstream of the gas outlet segment 66 of the expiratory bus 62 either directly or indirectly, for example, through one or more sub-buses 68, which arrangement is shown in Figs. 2 and 3. A connection upstream of the gas outlet segment 46 means that the gas flows from the expiratory pipes 64 in the direction of the gas outlet segment 66, from where the expiratory gas flows into the expiratory gas discharge subsystem 80.

For safe operation, it is preferred to use at least two inspiratory gas supply subsystems 20 in zone A and at least two expiratory gas discharge subsystems 80 in zone O, preferably connected to the same gas inlet segment 46 and gas outlet segment 66, respectively, but of course it is also possible to connect these to separate gas inlet segments 46 and gas outlet segments 66, respectively. Duplication of subsystems 20 and 80, on the one hand, protects against malfunctions due to failures and, on the other hand, allows for scheduled maintenance, such as the unhindered replacement of filters.

The ventilator 10 of the present invention preferably also has an operating system 90 that controls the active elements in each zone, if any (e.g., controllable valves for pressure control), and may collect data from measuring instruments located in each zone, if such instruments are capable of transmitting the measured data (e.g. telemetry sensors). The active elements are preferably controlled using the measurement data of the respective measuring instruments. The operating system 90 may be centralized or may consist of multiple local operator modules that either communicate with each other or not. The operating system 90 preferably includes data management, data processing, and display units. The data management may include, for example, the collection, storage and transmission of measurement data, the data processing may include the evaluation of the measurement data and the determination and transmission of control parameters based on it. The display unit preferably displays data to the user, preferably processed data, and provides for user intervention.

Further preferred embodiments of the ventilator system 10, which is generally shown in Fig. 1 , are described below. For the purpose of better illustration, Figs. 2 and 3 depict embodiments in more detail, but of course the preferred measures illustrated in Figs. 2 and 3 can also be implemented in the case of the ventilator system 10 according to Fig. 1 .

In the embodiment shown in Fig. 2, two inspiratory gas supply subsystems 20 are connected to the gas inlet segment 46 of the inspiratory bus 42 belonging to the gas supply pipe system 40 for the sake of redundancy.

The inspiratory gas supply subsystem 20 may receive the inspiratory gas, typically air, from a variety of sources. These may be buffer cylinders (for both air and oxygen), hospital pre-installed aeration pipe systems, or dedicated fan or compressor air supply systems. The combination or multiplication of the different types of air supply subsystems 20 increases the capacity and robustness of the ventilator system 10. In the present subsystems 20, a fan 22 driven by a motor 21 provides a supply of inspiratory gas at a pressure greater than ambient atmospheric pressure to the gas inlet segment 46 of the inspiratory bus 42 such that the fan 22 draws in ambient air on the intake side of the fan 22 and directs the air to the gas inlet segment 46 connected on the discharge side of the fan 22.

Similarly, the expiratory gas discharge subsystem 80 is preferably redundant as well, i.e. , two subsystems 80 are connected to the gas outlet segment 66 of the expiratory bus 62, wherein according to the present embodiment the suction effect is provided by a fan 82 driven by a motor 81 .

Flasonloan a kilegzesi gaz elvezeto 80 alrendszert is redundansan celszeru kiepiteni, vagyis ket 80 alrendszert csatlakoztatunk a 62 kilegzesi busz 64 gazkivezeto szegmensehez, amelyekben jelen esetben egy-egy 81 motorral hajtott 82 ventilatorral biztositjuk a szivo hatast. In front of the fans 22, 82, filters 24, 84, e.g. HEPA filters can be placed to eliminate contaminants of different size and pathogens. It is also advisable to place filters 24, 84 after the fans 22, 82, which prevent the passage of contaminants which may otherwise occur during the replacement of the external filters 24, 84 or during the operation of the motor 21 , 81 . As the filters 24, 84 become dirty, their resistance increases, the increased pressure difference is preferably monitored with a pressure gauge (not shown) so as not to exceed the performance of the motor driven fan 22, 82, in which case the operating point would be shifted to an undesired range. The heating resulting from the continuous operation of the fans 22, 82 should be monitored continuously by measuring the temperature to avoid overheating.

The motor 21 is preferably an electric motor, whereby no separate carbon dioxide filtration is required.

In order to increase the operational safety of the ventilator system 10, the power supply of the motors 21 driving the fans 22 should be realized with adequate redundancy and preferably by way of uninterruptible power supply.

The fans 22, 82 of each subsystem 20, 80 are separated from the inspiratory bus 42 and the expiratory bus 62, respectively, by a non-return valve 25, thereby preventing undesired flow of the gas in the opposite direction when the fan 22, 82 is stopped or stops. Undesired gas flow would mean that the pressurized air flows back from the gas inlet segment 44 to the subsystem 20 containing the inoperative fan 22, which would undesirably reduce the pressure in the gas supply pipe system 40. Another scenario would be that the operating fan 82 draws in air from the subsystem 80 containing the inoperative fan 82 through the gas outlet segment 66 of the expiratory bus 62, thereby undesirably reducing the airflow inside the expiratory bus 62. The fans 22, 82 may also shut down due to a malfunction, but may also be intentionally shut down, for example to replace the filters 24, 84 or to perform scheduled maintenance on the motors 21 , 81 or fans 22, 82.

To ensure the breathing of an adult, approximately an overpressure of 60 mbar is required, accordingly, preferably, the pressure on the inlet side 30a of the ventilator modules 30 is higher than the ambient atmospheric pressure by 60 mbar or slightly more, which can be reduced in the ventilator module 30 to the desired extent, for example by using a reducer. In the illustrated embodiment, an inspiratory bus 42 with an internal diameter of 125 mm, an inspiratory sub-bus 48 with an internal diameter of 50 mm, and five inspiratory pipes 44 connected thereto were used, and the average length of the gas supply pipe system 40 to the ventilator modules 30 was in average approx. 15 meters. With such sizing, it has been found appropriate to provide an overpressure of 80 to 100 mbar in the inspiratory bus 42 to provide an overpressure of 60 mbar on the inlet side 30a of the ventilator modules 30. Of course, in the case of a gas inlet pipe system 40 of a different size or arrangement, the required pressure may vary in a different range, which, however, can be easily determined by a person skilled in the art by calculation or simple testing. The desired pressure is achieved in case the speed of the motor 21 can be controlled, on the one hand by adjusting the appropriate fan speed 22 and, on the other hand (and also in the case of a motor 21 with fixed speed) by means of valves and/or flow restrictor of adjustable cross-section through which the pressurized air is allowed to exit at rate which reduces the pressure to the desired value on the inspiratory side. In the embodiment shown in Fig. 2, on the one hand, a mechanical pressure relief valve 49 is used in the inspiratory bus 62, which opens at a predetermined overpressure without any special intervention, thus ensuring that the pressure does not exceed a critical value at any time. Of course, the pressure relief valve 49 may be located elsewhere (e.g., in the inspiratory sub-bus 48), or multiple pressure relief valves may be used together in different segments of the gas supply pipe system 40. The other control option in this embodiment is provided by an adjustable cross-section flow restrictor 50 which is connected to the inspiratory restrictor segment 51 of the inspiratory bus 42 and through which the excess air flow can be discharged from the gas inlet pipe system 40 in order to reduce the pressure. The flow restrictor 50 may be mechanical or program controlled. Of course, other known solutions can be used, such as controllable valves.

Similarly, the exhaust pipe system 60 should be provided with a mechanical pressure limiter (or even more) to avoid undesired operating conditions, which function is provided in this case by a pressure relief valve 69. In addition, an adjustable cross-section flow restrictor 70 may be used to control the air flow here, which is connected to the expiratory restrictor segment 71 of the expiratory bus 62 and through which ambient air can be admitted to the gas discharge pipe system 60 in order to reduce the suction effect. Of course, this may be located elsewhere than the expiratory bus 62, such as inside the sub-bus 68 immediately upstream of its connection to the expiratory bus 62. The pressure conditions of the inspiratory and expiratory gases are determined and adjusted in such a way that no backflow or mixing can take place in the system.

The use of a gas discharge pipe system 60 to discharge exhaled air is particularly advantageous when ventilating infectious patients, as discharging exhaled air can reduce the potential risk of infection of staff working in the room. Exhaled air can be highly contagious, for this reason it is preferred to provide the expiratory bus 62, optionally the expiratory sub-bus 68, and the expiratory pipes 64 with distinctive markings and painting.

The expiratory air in the gas discharge pipe system 60 is depressed up to the pressure side of the fan 82, the pressure can be adjusted by the earlier described restrictor 70 or other valve located at the end of the expiratory bus 62, which pressure is preferably set to be 40-80 mbar less than the outside atmospheric pressure. Due to the lower than atmospheric pressure, no pathogen can get out of. The discharge side of the fan 82 should be designed to allow air to escape only after proper cleaning, which can be accomplished, for example, by using the filters 84 or other air purifiers previously described.

The inspiratory bus 42 may optionally include an air management segment 52 that measures and controls various important parameters of the air (e.g., temperature /heating-cooling/, humidity, etc.). This segment is optional because the parameters can be adjusted at other locations (e.g., in the patient zone previously referred to as zone P).

In the case of both the gas supply pipe system 40 and the gas discharge pipe system 60, it is preferred to protect against static electricity by means of a properly designed ESD (electric static discharge) protection and by earthing the pipes.

In the present embodiment, the management of the respiratory gases (filtration, temperature control, humidity control, pressure control, safety control, etc.) is performed in a distributed manner, under central supervision, in several places within the ventilator system 10, both automatically and manually.

Due to the modularity of the ventilator system 10, additional patients (one or more patients) can be integrated into the system up to the limit capacity of the system. The limit capacity of the system is mostly determined by the capacity of the motorized fans 21 , 81 22, 82 used on the inspiratory and expiratory side (important parameters: the volume and minimum pressure of the air made to flow through and the size limitations due to the environment).

Until the limit capacity is reached, the inspiratory and expiratory side pressures in the present case is adjusted to the desired value by means of the restrictors 50 and 70 (or adjustable valves triggering them) connected to the inspiratory restrictor segment 51 and the expiratory restrictor segment 71 of the inspiratory bus 42 and the expiratory bus 62, respectively. At least in the gas supply pipe system 40, it is advisable to continuously measure the volumetric flow rate in order to determine whether or not it is sufficient for the ventilator modules 30 in use which are connected to the ventilator system 10 and thus sufficient for the patients.

In the present embodiment, the following parameters are measured within the ventilator system 10: air temperature at least on the inspiratory side volumetric flow rate in the 42 inspiratory buses and 62 expiratory buses pressure drop on filters 22 and 82 pressure inside the 42 inspiratory bus and 62 expiratory bus air humidity oxygen concentration in the inspiratory gas.

It is also advisable to monitor the integrity of the system, i.e. whether there is a disturbing or impossible situation/event such as, in connection with the pipes: whether there is a leak somewhere in the system (this may be due to damage to the pipes or to pipes or valves being left open); regarding system monitoring: whether there is a “data leak”, whether data is collected from all locations within the data collection system, checking that no subsystems have fallen out and no security incidents have occurred.

Since some of the parameters are interrelated, the measurement of the listed parameters can be substituted by the measurement of other parameters. For example, knowing the cross-section of each pipe, volumetric flow rate measurement can be substituted by pressure measurement and calculation. It can also be said that instead of the measurements in the inspiratory bus 42 and the expiratory bus 62, more accurate results can be obtained for ventilation by performing measurements at the inlet side 30a and the outlet side 30b of the ventilator module 30, however, this requires more measuring devices, which makes the 10 ventilator system more expensive.

It is advisable to connect the ventilator modules 30 of the patients, illustrated by reference numerals P1 to P5, to the gas supply pipe system 40 and to the gas discharge pipe system 60 via separate fittings which can be sealed off, so that additional patients can be integrated into the ventilator system 10 without causing any disturbance in the operation of the entire ventilator system 10. The possibility of connection is indicated by a dashed line in Fig. 2.

At the end of both the inspiratory bus 42 and the expiratory bus 62, it is advisable to place a closing assembly 53 and 73, respectively, for further expandability, as illustrated in Fig. 4. In this embodiment, the ventilator system 10 is divided into larger segments, between which the closing assemblies 53, 73 (in both the expiratory and inspiratory subsystems) serve as sluice gates, which when opened allow for delivering air to another segment under given pressure conditions. A non-return valve 54 and 74 are preferably installed in front of the closing assembly 53 or after the closing assembly 73, so that the inspiratory bus 42 and the expiratory bus 62 are protected against undesired backflow even after expansion of the ventilator system 10. In this embodiment, the non-return valves 54 and 74 are provided with closures 55 and 75 which, when closed, do not permit opening of the non-return valves 54 and 74. The closures 55 and 75 are used during the expansion process to prevent inspiratory gas from escaping from the inspiratory bus 42 through the non-return valve 54 and to prevent ambient air from entering the expiratory bus 62 through the non-return valve 74 when the closing assemblies 53 and 73 are opened, respectively. The closures 55 and 75 can be, for example, manually operated mechanical isolating cocks, but of course remotely controlled systems can also be used.

In the embodiment shown in Figs. 2 and 3 the end of the inspiratory sub bus 48 opposite the inspiratory bus 42 is provided with an inspiratory segment closure 56, while the end of the expiratory sub-bus 68 opposite the expiratory bus 62 is provided with an expiratory segment closure 76. If both the inspiratory sub-bus 48 and the expiratory sub-bus 68 are to be expandable, then preferably a non-return valve and a closure for the non-return valve are provided adjacent the closures 56, 76. Of course, other known solutions can be used to prevent the outflow of inspiratory air or to prevent the inflow of ambient air.

Fig. 3 is a schematic block diagram of an exemplary embodiment of a ventilator module 30 in zone P. The ventilator module 30 is indicated by a dashed rectangle. The ventilator module 30 has a connector 31a on the inlet side 30a and a connector 31 b on the outlet side 30b, through which the ventilator module 30 can be connected to one of the inspiratory pipes 44 on the inspiratory side and to one of the expiratory pipes 64 on the expiratory side. Within the ventilator module 30, the inspiratory gas is delivered via internal conduits 32a to a controllable valve 33 from which it exits either in the direction of the connector 31 b via conduit 32b or is routed through conduit 32c to a patient interface 34 through which the ventilator module 30 can be connected to the patient. The patient interface 34 may be, for example, any tube or mask used for ventilation, accordingly, this is a replaceable element which is indicated by the fact that it is depicted as being outside of the ventilator module 30.

In this embodiment, appropriate control of the valve 33 serves to ensure that the inspiratory gas pressure is sufficient to provide for respiration. In case of artificial ventilation of adult patients this requires an overpressure of approx. 60 mbar relative to the ambient atmospheric pressure, in case of assisting spontaneous breathing this pressure can be reduced in accordance with the suction power of the patient's lungs. An oxygen blender 35, which is commonly used in ventilators, is connected along conduit 32c after the valve 33. Because the inspiratory gas provided by the subsystem 20 is simple ambient air that is not enriched with oxygen, it does not provide an adequate supply of oxygen to patients who have decreased oxygen absorbing respiratory area due to, for example, pneumonia. When ventilating such patients, the blender 35 may be used to mix oxygen from an external, replaceable oxygen cylinder 92 or other oxygen source via conduit 32d to the inspiratory gas.

After the blender 35, sensors 36 are preferably arranged, preferably pressure and volumetric flow rate sensors 36, which are schematically illustrated here by a single block, to measure the pressure and the volumetric flow rate of the delivered gas in the conduit 32c leading to the patient interface 34.

Preferably, prior to the patient interface 34, a conventional heat and humidity control device is connected to the conduit 32c, such as a passive or active heat and moisture exchanger (HME) 37, the filter cartridge of which may also perform additional pathogen filtration.

Patients receive air based on personalized ventilation parameters (e.g., respiratory rate, duration of inspiration and exhalation, pressure, volume, shape of the curve describing their time dependence, etc.). A intelligent metering-feeding- mixing air management controller 38 is responsible for the personalized ventilation, which in the present embodiment is regarded as part of the ventilator module 30 because it is located in the proximity of the patient, but this is not necessarily the case, e.g. the parameters of the personalized ventilation of a plurality of ventilator modules 30 may be set remotely by a common controller 38.

The controller 38 may include a PID controller implemented on a microcontroller responsible for control. However, the controller 38 may be more complex in design, even a smartphone, tablet, or computer can fulfil this function.

The controller 38 may control the operation of the blender 35 to determine the oxygen concentration of the inspiratory air. The controller 38 may also control the valve 33 to adjust the pressure, respiratory rate, duration of inspiration and expiration, pressure curve used during inspiration and expiration, and volumetric flow rate curve.

A possible embodiment of the valve 33 developed by the inventors is shown in Fig. 3a. The valve 33 has a cylindrical valve housing 331 in which a valve body 332 is rotatably arranged along the longitudinal axis t of the valve housing 33. The valve body 332 is fitted in the valve housing 331 with a gap (without the need for a seal) to allow it to rotate easily. Only clean (filtered) air can leak from the valve 33 because the potentially infectious exhalation side is depressed, so no virus can escape from there.

The valve body 332 is rotated by a stepper motor 333 through a shaft 334 driven by the stepper motor 333. The valve housing 331 is provided with openings 335a, 335b, to which the conduits 32a and 32b, respectively, are connected directly or indirectly. Inside the valve body 332, a central longitudinal bore 336 is formed which is open from the end of the valve body 332 opposite the stepper motor 333 and can be connected to the conduit 32c either directly or indirectly. In the wall of the valve body 332, in the longitudinal position corresponding to the openings 335a and 335b, radial bores 337a, 337b opening into the longitudinal bore 336 are formed in two positions rotated at an angle of 90 degrees relative to each other. The valve body 332 has two end positions: in the first end position shown in Fig. 3a, the radial bore 337a in the wall of the valve body 332 overlaps maximally with the opening 335a of the valve body 331 allowing the greatest amount of inspiratory air to flow through the conduit 32a into the inner longitudinal bore 336 and therethrough to the conduit 32c leading to the patient interface 34. The other radial bore 337b lies in a perpendicular direction whereby the wall of the valve body 332 completely closes the other opening 335b of the valve housing 331 , so that the inspiratory air entering the inner bore 336 of the valve body 332 cannot escape to the exhalation side 32b. In the other end position, the bore 337b overlaps the opening 335b of the valve body 332 at a maximum extent, while the wall of the valve body 332 closes the opening 335a. In this end position, exhaled air flows from the direction of the patient interface 34 through the valve 33 to the conduit 32c and from there through the gas discharge pipe system 60 in the expiratory gas discharge subsystem 80.

From the first end position shown in Fig. 3a, the valve body 332 is rotatable in a direction which moves the radial bore 337a away from the opening 335a of the valve housing 331 and approaches the bore 337b to the opening 335b. Consequently, when the valve body 332 is rotated from the end position shown in Fig. 3a, the radial bore 337a of the valve body 332 overlaps less and less with the opening 335a of the valve body 331 , so that the cross-section allowing gas flow in the inspiratory direction is continuously reduced. Meanwhile, the bore 337b of the valve body 332 increasingly overlaps the opening 335b of the valve body 331 , thereby increasing the flow cross-section in the expiratory direction. In the positions between the two end positions, a portion of the inspiratory airflows from the conduit 32a coming from the inlet side 30a through the valve 33 directly to the conduit 32b leading to the outlet side 30b, whereby the pressure and volumetric flow rate of the inspiratory air flowing to the patient interface 34 through the conduit 32c is determined by the ratio of the flow cross-sections formed at the openings 335a and 335b. The design of the valve 33 is thus such that by rotating the valve body by 90° it is possible to reach a state of 100% extraction from a state of 100% supply. At a position of approximately 45°, both the supply and exhaust directions are slightly open, in which case a flow short-circuit is formed inside the valve body 332. As a result, the fine regulation of the patient-side pressure (i.e. , the pressure at the patient interface 34) is made possible.

Thus, this is a three-way valve 33, the first passage of which is the opening 335a of the valve housing 331 , the second passage is the opening 335b of the valve housing 331 , and the third passage is the longitudinal bore 336 of the valve body 332 between which the bores 337a and 337b are capable of allowing gas communication. The same principle of operation can be achieved with other bore configurations, for example the bores 337a, 337b do not have to be radial, any bore- direction that is transversal to the longitudinal axis t is allowed as long as it can connect the outer side of the valve housing 333 with the inner longitudinal bore 336. It is also not necessary for the openings 335a, 335b to be located along a line parallel to the longitudinal axis t. If the openings 335a, 335b are not only offset relative to one another in the direction of the longitudinal axis t, but are also rotated relative to one another along the circumference of the valve housing 331 , then the position of the outer openings of the bores 337a, 337b can be adjusted accordingly. From an operational point of view, it is sufficient to ensure that the bores 337a, 337b are positioned such that by rotating the valve body 332 about the longitudinal axis t, the first bore 337a overlaps the first opening 335a of the valve housing 331a in a first position while the second bore 337b is covered by the wall of the valve housing 331 , and the second bore 337b overlaps the second opening 335a of the valve housing 331 in a second position, while the bore 337a is covered by the wall of the valve housing 331 .

The three-way valve 33 my be provided in different form as well, such as in the form of three passages arranged in an Y wherein a tilting tongue can close a first one of two of the passages and open a second one of the two passages in one end position of the tilting tongue, and in the other end position of the tilting tongue, vice versa, the second passage is opened and the first passage is closed, and anywhere between the two end positions there is a different degree of opening and closing in the direction of the first and second passages. An embodiment is also conceivable wherein the three-way valve 33 is realized by assembling several valves.

By controlling the stepper motor 333 the patient-side pressure and volumetric flow rate can be controlled. The control is preferably based on the measurement data of the sensors 36 connected after the blender 35, whereby the pressure and volumetric flow rate are measured after the oxygen is added to the air, and depending on these values, the controller 38 will readjust the position of the valve 33.

The patient receives inspiratory air from the inspiratory sub-bus 48 of the ventilator system 10 via the controlled valve 33. In the embodiment shown in Fig. 3a, the design of the valve 33 is such that by rotating the valve body 332 therein between the end positions, a state from maximum supply to a state of maximum extraction can be achieved. This allows the patient side pressure to be fine-tuned. By reducing the flow cross-section in the direction of the overpressure side upstream of the valve 33 (direction of the inspiratory sub-bus 48) and in the direction of the depressed side (towards the expiratory sub-bus 68) to varying degrees, the desired pressure and flow can be set for the patient downstream of the valve 33 (in the P- zone).

Air pressure and flow control can be implemented with active or passive control circuit. With model-based calibration, in addition to complex mechanisms, even a simple (but efficient) control circuit can be created and pressure and flow control can be implemented in the valve 33 with the simple stepper motor position control shown in Fig. 3a.

The stepper motor 333 activating the valve 33, controls the desired pressure from a reference position corresponding to the zero point. The zero point position of the valve 33 depends on the pressure conditions of the BB zone and the KB zone and the characteristics of the valve 33. In order to compensate for the characteristics of the valve 33 pressure may be measured before and after the valve 33 in order to compensate for the zero characteristic shift due to the pressure asymmetry of the BB zone and KB zone and the manufacturing inaccuracy of the valve 33. Fig. 3 only depicts the sensor 36 in the direction of the patient interface 34 but, of course, to increase accuracy, or for the purpose of calibration additional sensors can be installed. The three pressure values can be used to calculate the zero point position using a pre-calibrated model of the valve 33 (this is called model-based calibration). Thanks to the model-based calibration, the active control circuit is more simple and pressure and flow control can be implemented by controlling the position of the stepper motor 333. The stepper motor 333, when used in microstep mode, allows for sufficiently precise positioning and thus control. In the P-zone, the ventilator module 30 provides several possibilities for adjusting the oxygen concentration of each patient: the oxygen supply can be achieved with concentration-based or time-based control. Obtaining relatively expensive and accurate oxygen sensors for concentration-based control and continuous (periodic) replacement in an epidemic situation is difficult. With time- based control, the accuracy is lower, but it is still suitable for operation. The blender 35 can be provided with a constant amount of oxygen gas delivered per unit time using a mechanical flow control valve, which is delivered to the patient by controlling the flow control valve for an appropriate amount of time. Thanks to the mechanical flow regulator, the amount of oxygen introduced does not depend on the pressure difference between the oxygen supply system (e.g. the oxygen cylinder 92 or an oxygen supply network) and the P-zone, only the time. In flow control mode, a set amount of ambient air is supplied so that the required oxygen can be calculated accurately. In pressure control mode, depending on the patient's condition and parameters (which may change over time), different amounts of ambient air can be delivered, so that the required amount of additional oxygen for obtaining a desired oxygen concentration can be calculated using measured data from the previous breathing cycle (negligible deviation between two cycles).

The temperature and humidity of the air supplied to the patient can be managed in both zone BB and zone P. In zone P, close to the patient's mouth, upstream of the 34 patient interface, it is possible to set the desired values both with passive (e.g. HME - Heat and Moisture Exchanger) or active solutions (e.g. HME Booster).

Due to the design of the system, the P-zone is not completely closed from either the BB zone or the KB zone, thus ensuring free breathing of the patient, which is detected by the pressure measuring sensor 36. When the patient breathes spontaneously, the pressure decreases, and increases with exhalation, when this is detected, the controller 38 brings the valve 33 to the appropriate position, whereby spontaneous inhalation and exhalation can take place. In addition to the fact that the ventilator module 30 is able to operate in synchrony with the patient's breathing cycle, it can also be detected if the patient draws air at a different rate from the pressure change, and the controller 38 can be used in this situation as well to position the valve 33 such as to allow inhalation and exhalation, and to provide the appropriate pressure.

Due to the modularity of the ventilator system 10, additional patients can be integrated into the system without having to stop ventilating already connected patients. On the one hand, patients can be connected to the fixed individual ventilator modules 30 or additional ventilator modules 30 can be connected to the free inspiratory pipes 44 and expiratory pipes 64 of the existing inspiratory and expiratory buses 48, 68, respectively. On the other hand, according to this embodiment, it is also possible to expand the inspiratory and expiratory buses 42 and 62, respectively, as shown in FIG 4.

In the expanded system shown in Fig. 4, there are two system modules 100, each comprising an inspiratory bus 42 and an expiratory bus 62, to each of which an inspiratory sub-bus 48 and an expiratory sub-bus 68 is connected, respectively, and one or more patients may be connected to these simultaneously (zone P is not explained in more detail). In this embodiment, the second system module 100 is not only expandable at the bus ends, but the inspiratory sub-bus 48 is also provided with a closure 57 and a non-return valve 58 upstream of the inspiratory segment closure 56, and the expiratory sub-bus 68 is also provided with a closure 77 and a non-return valve 78 downstream of an expiratory segment closure 76 so that the sub-buses can also be expanded, as illustrated by an expansion point.

Patients within the same system module 100 can be individually integrated into that system module 100 or be removed from the system module 100 at any time, independently of the other patients. The connection and disconnection of a particular patient to the ventilator system 10 is preferably accomplished by patient- level control.

In an exemplary embodiment, unified monitoring of the patients and the mass ventilator system 10 and patients may be performed as follows.

The mass ventilator system 10 as well as all ventilated patients are monitored within the unified operating system 90. Measurement data, derived values and statistics are uploaded to the local (central) server(s) via a wireless network with a properly encrypted (authenticated) communication channel. Since mass ventilation makes it possible in principle for many patients to be ventilated over a relatively large area, it may be necessary to integrate wireless so-called Access Points (APs) into the system to overcome larger distances. The monitoring subsystem of the operating system 90 (not illustrated) shows the different parts of the system and the monitored parameters of these parts to different persons based on their rights and tasks. The monitoring subsystem preferably provides data communication to the personal ventilators and to the software that monitors them, as well as to the HIS (Hospital Information System) and higher level epidemic monitoring systems.

It will be apparent to those skilled in the art that various modifications are conceivable to the above disclosed embodiments without departing from the scope of protection determined by the appended claims.

Claims

1. A ventilator system comprising an inspiratory gas supply subsystem for supplying gas at a pressure above ambient atmospheric pressure, a ventilator module connectable therewith through a gas supply pipe system allowing gas communication, and comprising a gas discharge pipe system for discharging gas from the ventilator module, characterised by comprising a plurality of ventilator modules each having an inlet side and an outlet side, the gas supply pipe system comprising an inspiratory bus having a gas inlet segment and comprising a plurality of inspiratory pipes which are connected directly or indirectly to the inspiratory bus downstream of the gas inlet segment, each inspiratory pipe is connected to or connectable to the inlet side of one of the plurality of ventilator modules, and the inspiratory gas supply subsystem is connected to the gas inlet segment of the inspiratory bus for delivering inspiratory gas at a first pressure higher than the ambient atmospheric pressure into the gas inlet segment, the gas discharge pipe system comprising an expiratory bus having a gas outlet segment and comprising a plurality of expiratory pipes which are connected directly or indirectly to the expiratory bus upstream of the gas outlet segment, and each expiratory pipe is connectable to the outlet side of one of the plurality of ventilator modules, the ventilator system further comprising an expiratory gas discharge subsystem being in gas communication with the gas outlet segment of the expiratory bus for producing a second pressure lower than the ambient atmospheric pressure in the gas outlet segment.

2. The ventilator system according to claim 1 , characterised in that it comprises at least two inspiratory gas supply subsystems, each connected to the gas inlet segment of the inspiratory bus and/or at least two expiratory gas discharge subsystems, each connected to the gas outlet segment of the expiratory bus.

3. The ventilator system according to claims 1 or 2, characterised in that the inspiratory bus has a first cross-section, the inspiratory pipes have a second cross-section which is smaller than the first cross-section, the expiratory bus has a third cross-section and the expiratory pipes have a fourth cross-section, which fourth cross-section is smaller than the first and third cross-sections, and preferably the first and third cross-sections are substantially of the same size.

4. The ventilator system according to any one of claims 1 to 3, characterised in that the inspiratory pipes are connected to the inspiratory bus via at least one inspiratory sub-bus having a fifth cross-section smaller than the first cross-section and larger than the second cross-section and/or the expiratory pipes are connected to the expiratory bus via at least one expiratory sub-bus, which expiratory sub-bus has a sixth cross-section smaller than the third cross-section and larger than the fourth cross-section.

5. The ventilator system according to any one of claims 1 to 4, characterised in that the inspiratory gas supply subsystem comprises a fan driven by an electric motor or a gas compressor or a pressurized buffer cylinder filled with inspiratory gas, optionally oxygen-enriched air.

6. The ventilator system according to any one of claims 1 to 5, characterised in that the expiratory gas discharge subsystem comprises a fan driven by an electric motor or an air pump.

7. A The ventilator system according to any one of claims 1 to 6, characterised in that the inspiratory gas supply subsystem and/or the expiratory gas discharge subsystem has an air filter, e.g. includes HEPA filter.

7. The ventilator system according to any one of claims 1 to 6, characterised in that the subsystems are connected to buses via non-return valves.

8. A The ventilator system according to any one of claims 1 to 7, characterised in that the gas supply pipe system and the gas discharge pipe system comprise pressure regulating elements for adjusting the pressure, such as restrictors, controllable valves, pressure relief valves.

9. The ventilator system according to any one of claims 1 to 8, characterised in that the ends of the inspiratory bus and the expiratory bus opposite the subsystems are designed to allow further modular connection of further bus segments.

10. The ventilator system according to any one of claims 1 to 9, characterised in that the ventilator module comprises a three-way valve of controllable position having a first passage connected to the inlet side, a second passage connected to the outlet side and a third passage connected to a conduit provided for connecting to a patient to be ventilated.

11. The ventilator system according to claim 10, characterised in that an oxygen blender connectable to an external oxygen source is interposed along the conduit that is provided for connecting to the patient to be ventilated.

12. The ventilator system according to claim 11 , characterised in that a sensor is installed in the conduit provided for connecting to the patient to be ventilated on the side of the oxygen blender opposite the valve, and the ventilator system comprises a controller data transferably connectable to the sensor for controlling the valve and the oxygen blender based on data measured by the sensor.

13. A three-way valve, characterised by comprising a valve housing and a valve body rotatably arranged therein about a longitudinal axis, a wall of the valve housing having first and second openings spaced apart along the longitudinal axis, the valve body having a longitudinal bore opening from a first end of the valve body and being closed from a second end of the valve body, a wall of the valve body having first and second radial bores opening into the longitudinal bore, which are arranged such that by rotating the valve body about the longitudinal axis, in a first position the first radial bore overlaps the first opening of the valve housing while the second radial bore is covered by the wall of the valve housing, and in a second position, the second radial bore overlaps the second opening of the valve housing, while the first radial bore is covered by the wall of the valve housing.

14. A three-way valve according to claim 13, characterised in that the valve comprises a stepping motor having a driven shaft which is connected to the second end of the valve body for rotating the valve body.