O2 concentrator having a sheave bed bypass circuit and its control method

Abstract

To provide an oxygen concentrator configured to generate high oxygen concentration gas delivered to a patient by a ventilator.SOLUTION: An oxygen concentrator (100) includes one or more adsorbent sieve beds (120) operable to remove nitrogen from air to produce concentrated oxygen gas at respective outlets thereof, a product tank (130) fluidly coupled to the respective outlets of the sieve bed(s), a compressor (110) operable to pressurize ambient air, one or more sieve bed flow paths from the compressor to respective inlets of the sieve bed(s), a bypass flow path (170) from the compressor to the product tank that bypasses the sieve bed(s), and a valve unit (150) operable to selectively allow flow of pressurized ambient air from the compressor along the sieve bed flow paths and along the bypass flow path in response to a control signal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] ==Cross - Reference to Related Applications== This application relates to U.S. Provisional Patent Application No. 62 / 851,204, filed on May 22, 2019, with the invention titled "O2 CONCENTRATOR WITH SIEVE BED BYPASS AND CONTROL METHOD THEREOF (Oxygen concentrator having a sieve bed bypass and its control method)", and claims the benefit of the priority of the provisional application, the entire content of which is expressly incorporated herein by reference.

[0002] 1. Technical Field to Which the Invention Belongs

[0003] The present disclosure relates generally to oxygen concentrators, and more particularly to an oxygen concentrator configured to produce a high - oxygen - concentration gas to be sent to a patient by a ventilator.

Background Art

[0004] 2. Description of Related Applications

[0005] In a wide range of clinical conditions, some form of ventilation therapy may be required. In such ventilation therapy, the breathing motion of a patient is assisted by the flow of pressurized gas sent from a ventilator to the patient's airway. These conditions include hypoxemia, various forms of respiratory failure, airway disorders, etc. There are also non - respiratory and non - airway diseases that require ventilation therapy, such as congestive heart failure and neuromuscular diseases.

[0006] To improve the quality of life of many patients who require long-term ventilation therapy, small, portable ventilation systems have been developed. Some of these systems, such as the Life2000® system of Breathe Technologies, Inc., are very lightweight and compact and can be worn by patients, either in an extended range or stand-alone configuration. The operation of these systems uses a source of pressurized ventilation gas. In a fixed or extended range configuration, the source of pressurized gas may be a stationary compressor unit that can be stored in the patient's home. In a stand-alone configuration, which is typically used when the patient is outside the home, a portable, wearable ventilator generally receives its ventilation gas from a pressurized gas cylinder or a portable compressor.

[0007] Many of the above clinical conditions and other clinical conditions require or can benefit from oxygen supplementation therapy. In such a method, the presence of additional oxygen increases the gas introduced into the patient's airway, and the patient inhales a gas with an oxygen level above the atmospheric concentration (20.9% at 0% humidity). In oxygen supplementation therapy, the patient generally needs to receive supplemental oxygen gas from an oxygen gas supply source that is a compressed oxygen cylinder, a cryogenic oxygen cylinder, or an oxygen gas generator. For many years, patients who desired to move around were dependent on oxygen cylinders. However, in recent years, with the miniaturization and improvement of battery technology, portable oxygen concentrators have been developed.

[0008] Portable oxygen concentrators generally operate by pressure swing adsorption (PSA). In this method, ambient air is pressurized by a compressor and passed through an adsorbent sieve bed. The sieve bed is generally formed of zeolite and preferentially adsorbs nitrogen at high pressure when oxygen passes through. When the sieve bed reaches its nitrogen adsorption limit, the pressure can be reduced. This pressure reduction allows the adsorbed nitrogen to desorb and be purged, leaving a regenerated sieve bed capable of re-adsorbing nitrogen. By repeating this operation, a gas with a high oxygen concentration can be generated. Generally, portable oxygen concentrators have at least two sieve beds, so that while one is operating, the other has nitrogen purged and discharged. Current common portable oxygen concentrators output oxygen-rich gas with an oxygen purity of approximately 87 - 96%. There are generally two types of existing oxygen concentrators that can be considered portable (especially by individuals suffering from respiratory diseases). The first, larger and heavier type can usually provide a continuous flow supply. The weight of models of this type is generally 5 - 10 kg, the maximum flow rate is generally 5 - 6 liters per minute or less, and it usually has a configuration with wheels and a handle and often looks like a suitcase. The second type is a lightweight unit suitable for carrying and wearing in a satchel, handbag, or backpack. The weight of models of this type is generally less than 2.5 kg, and it is usually limited to a pulse supply mode with a maximum flow rate of about 2 liters per minute or less. Summary of the Invention Problems to be Solved by the Invention

[0009] Since pressurized oxygen cylinders require continuous replenishment or replacement, portable oxygen concentrators have significant advantages in terms of cost and convenience compared to pressurized oxygen cylinders. In addition, portable oxygen concentrators are considered to be much safer than pressurized oxygen cylinders. Such safety aspects can have a major impact on the quality of life of patients. This is because many portable oxygen concentrators are approved by the FAA for use by travelers on commercial aircraft, while oxygen cylinders are generally prohibited on commercial flights. As a result, patients wearing pressurized oxygen cylinders must either make time-consuming and costly preparations in advance with the airline or completely refrain from traveling by air.

[0010] For patients who do not need to assist with breathing movements, oxygen supplementation therapy without ventilation therapy may be sufficient in some cases. However, for many patients, a combination of ventilation therapy and oxygen supplementation therapy may be the optimal treatment. In healthy patients, for sufficient ventilation to perform breathing movements, usually a minute ventilation volume of 5 to 8 L / min is required at rest, it may double with light exercise, and may exceed 40 L / min with strenuous exercise. In patients with respiratory diseases, the required values may be significantly higher, and the instantaneous values may also be significantly higher. Since such patients often also need light exercise, this is particularly true when the patient is outside the home and requires portability.

[0011] Thus, in many cases, due to the fact that existing portable oxygen concentrators do not output gas at a high enough pressure and / or volume to be used in combination with a wearable portable ventilator without an additional compressed gas supply source, it can be seen that patients who prefer treatment in the combined mode are substantially restricted. Therefore, if maximum portability is desired, these patients must either forego the substantial advantages of portable oxygen concentrators and return to (oxygen cylinders that can output oxygen gas at the high pressures and flows required for ventilation therapy) or acquire a portable compressor with a portable oxygen concentrator, a portable compressor, and a wearable ventilator combined.

[0012] Existing systems and methods attempting to provide a combined oxygen supplementation / ventilation system have substantial drawbacks. For example, U.S. Patent Application Publication Nos. 2017 / 0340851 and 2018 / 0001048 describe adding an accumulator tank downstream of the product tank of an oxygen concentrator for the purpose described in the specification of providing a more consistent flow of product gas to a mechanical ventilator. U.S. Patent Application Publication No. 2017 / 0113013 describes using product tank pressure and output flow rate measurements to determine whether an oxygen concentrator is fluidly connected to a ventilator (which may feature the use of oxygen-rich gas from the oxygen concentrator in intermittent spontaneous bursts). If so, the valve or pump of the oxygen concentrator is controlled to increase or decrease the pressure or gas flow rate of the product tank to meet the supply gas requirements of the ventilator. Such systems can generally be understood to be aimed only at meeting the course requirements of the ventilator, such as ensuring that the pressure in the product tank does not fall below some threshold. None of them can meet the specific needs of patients undergoing ventilation therapy. U.S. Patent Application Publication No. 2017 / 0113013 contemplates determining an indicator of the patient's condition, but this determination is based solely on measurements within the concentrator and is only a rough estimate. Means for Solving the Problems

[0013] In the present disclosure, various systems, methods, and apparatuses are contemplated to overcome the above-described drawbacks associated with the related art. One aspect of an embodiment of the present disclosure is one or more adsorbent sieve beds operable to remove nitrogen from air and create enriched oxygen gas at respective outlets, a product tank fluidly connected to respective outlets of the one or more adsorbent sieve beds, a compressor operable to pressurize ambient air, one or more sieve bed flow paths from the compressor to respective inlets of the one or more adsorbent sieve beds, a bypass flow path from the compressor to the product tank bypassing the one or more adsorbent sieve beds, and a valve unit operable to selectively direct the pressurized ambient air flow from the compressor either along the one or more sieve bed flow paths or along the bypass flow path in response to a control signal, an oxygen concentrator comprising.

[0014] The valve unit may include one or more ON / OFF valves, and the valve unit may selectively enable the flow of pressurized ambient air from the compressor along the one or more sieve bed flow paths and the flow along the bypass flow path by selectively adjusting the timing of the states of the one or more ON / OFF valves with respect to the operating cycle of the one or more adsorbent sieve beds.

[0015] The valve unit may include one or more proportional valves, and the valve unit may selectively enable the flow of pressurized ambient air from the compressor along the one or more sieve bed flow paths and the flow along the bypass flow path by selectively adjusting the magnitude of the input to the one or more proportional valves. Further, the valve unit may selectively enable the flow of pressurized ambient air from the compressor along the one or more sieve bed flow paths and the flow along the bypass flow path by selectively adjusting the timing of the states of the one or more proportional valves with respect to the operating cycle of the one or more adsorbent sieve beds.

[0016] The oxygen concentrator may further include a controller operable to generate a control signal. The control signal generated by the controller may operate the valve unit to maintain a preset oxygen concentration within the product tank. The controller may generate a control signal in response to a command issued by a ventilator fluidly connected to the outlet of the product tank.

[0017] Another aspect of an embodiment of the present disclosure is a system including the oxygen concentrator described above and the ventilator described above. The ventilator may calculate a preset oxygen concentration based on the oxygen concentration input by the user. The ventilator may further calculate a preset oxygen concentration based on the measured ventilation gas output of the ventilator. The ventilator may further calculate a preset oxygen concentration based on the measured pressure in the patient ventilation interface of the ventilator.

[0018] The ventilator may include a flow sensor for measuring the flow rate of the gas discharged by one or more nozzles of the patient ventilation interface connected to the ventilator, a pressure sensor for measuring the pressure in the patient ventilation interface, and a master controller configured to issue a command based on the measured flow rate and the measured pressure. The master controller may be configured to issue a command based on the calculated total flow rate of the intake air and the gas sent by the ventilator as a function of the measured flow rate and the measured pressure. The master controller may be configured to issue a command based on the comparison result between the measured pressure and the multiple measured values of the total flow rate of the intake air and the gas sent by the ventilator stored corresponding to the multiple measured values of the pressure in the patient ventilation interface for the measured flow rate. The master controller may be configured to issue a command based on the measured pressure and the multiple measured values of the total flow rate of the intake air and the gas sent by the ventilator stored corresponding to the multiple measured values of the pressure in the patient ventilation interface for the measured flow rate, and the measured pressure, and the inhaled oxygen Concentration( %FiO 2) It may be configured to issue a command based on a comparison result with a plurality of measurement values.

[0019] The control signal generated by the controller may operate the compressor so as to maintain a preset oxygen concentration in the product tank.

[0020] Another aspect of the embodiments of the present disclosure is one or more adsorbent sieve beds, one or more adsorbent sieve beds operable to remove nitrogen from air and create enriched oxygen gas at each outlet, a product tank fluidly connected to each outlet of the one or more adsorbent sieve beds, a compressor operable to pressurize ambient air, one or more sieve bed flow paths from the compressor to each inlet of the one or more adsorbent sieve beds, a bypass compressor different from the above compressor and operable to pressurize ambient air, a bypass flow path from the bypass compressor to the product tank bypassing the one or more adsorbent sieve beds, and a controller operable to generate a control signal for controlling the bypass compressor and selectively enable the flow of pressurized ambient air from the bypass compressor along the bypass flow path, an oxygen concentrator.

[0021] Another aspect of an embodiment of the present disclosure is one or more adsorbent sieve beds operable to remove nitrogen from air and produce enriched oxygen gas at each outlet, a product tank fluidly connected to each outlet of the one or more adsorbent sieve beds, a compressor operable to pressurize ambient air, one or more sieve bed flow paths from the compressor to each inlet of the one or more adsorbent sieve beds, a bypass flow path from an external compressor fluid port around the one or more adsorbent sieve beds to the product tank, and a controller that generates a control signal for controlling an external compressor fluidly connected to the external compressor fluid port via an external compressor signal port, the control signal selectively enabling flow of pressurized ambient air from the external compressor along the bypass flow path, an oxygen concentrator.

[0022] Another aspect of an embodiment of the present disclosure is a modular system including the oxygen concentrator described above, an oxygen concentrator module housing the oxygen concentrator, and a compressor module housing an external compressor. The oxygen concentrator module and the compressor module can be removably attached from a single unit.

[0023] Another aspect of an embodiment of the present disclosure is a method for controlling an oxygen concentrator to meet a patient's ventilation and oxygen supplementation needs at multiple activity levels of the patient. The method may include transitioning the oxygen concentrator to a first configuration in which a first portion of ambient air, equal to or greater than no ambient air, mixes with the enriched oxygen gas output by one or more sieve beds of the oxygen concentrator to produce a concentrator output at a first flow rate that is a first oxygen concentration. The method may further include transitioning the oxygen concentrator to a second configuration in which a second portion of ambient air, greater than the first portion, mixes with the enriched oxygen gas output by one or more sieve beds to produce a concentrator output at a second flow rate that is a second oxygen concentration. The second flow rate is greater than the first flow rate and the second oxygen concentration is lower than the first oxygen concentration.

[0024] Another aspect of embodiments of the present disclosure is a method for controlling an oxygen concentrator to meet a patient's ventilation and oxygen supplementation needs at multiple activity levels of the patient. The method may include transitioning the oxygen concentrator to a first configuration in which a first portion of the concentrated oxygen gas output by one or more sieve beds of the oxygen concentrator, which is equal to or greater than no concentrated oxygen gas, mixes with ambient air to produce a concentrator output at a first flow rate that is a first oxygen concentration. The method may further include transitioning the oxygen concentrator to a second configuration in which a second portion of the concentrated oxygen gas output by one or more sieve beds, which is greater than the first portion, mixes with ambient air to produce a concentrator output at a second flow rate that is a second oxygen concentration. The second flow rate is less than the first flow rate, and the second oxygen concentration is higher than the first oxygen concentration.

[0025] Another aspect of embodiments of the present disclosure is a method for calculating the total flow rate of gas sent to a patient by a ventilator and intake air. The method may include storing one or more constants associated with each of a plurality of nozzle shapes, measuring the flow rate of gas discharged by one or more nozzles of a patient ventilation interface connected to the ventilator, the one or more nozzles having a nozzle shape corresponding to one of the plurality of nozzle shapes, measuring the pressure of the patient ventilation interface, and calculating the total flow rate based on the measured flow rate, the measured pressure, and the one or more constants stored in relation to the nozzle shape of the one or more nozzles.

[0026] The method may further include transmitting a signal to the oxygen concentrator based on the total flow rate determined by the calculation.

[0027] The method may further include calculating the total inspiratory volume by integrating the total flow rate determined by the calculation over time. The method may further include transmitting a signal to the oxygen concentrator based on the total inspiratory volume determined by the calculation.

[0028] This method includes calculating the inspiratory volume of the gas discharged by one or more nozzles by time-integrating the measured flow rate, calculating the inspiratory volume of the intake air by time-integrating the intake flow rate, which is the difference between the total flow rate obtained by calculation and the measured flow rate, and calculating the inhaled oxygen of the patient based on the inspiratory volume of the gas discharged from one or more nozzles and the inspiratory volume of the intake air. Concentration( %FiO 2 ) It may further include calculating the %FiO 2 calculated by the method. It may further include sending a signal to the oxygen concentrator based on the %FiO

[0029] For each of the plurality of nozzle shapes, one or more associated constants are stored in a memory disposed in a patient ventilation interface having a nozzle with that nozzle shape. Calculating the total flow rate may include reading one or more constants stored in a patient ventilation interface connected to the ventilator.

[0030] Another aspect of the embodiments of the present disclosure is a method of controlling an oxygen concentrator based on the total flow rate of the gas and the intake air sent to a patient by a ventilator. This method includes measuring the flow rate of the gas discharged by one or more nozzles of a patient ventilation interface connected to the ventilator, measuring the pressure within the patient ventilation interface, calculating the total flow rate based on the measured flow rate and the measured pressure, and sending a signal to the oxygen concentrator based on the calculated total flow rate.

[0031] This method may further include calculating the total inspiratory volume by integrating the calculated total flow rate over time. The signal transmission may be based on the calculated total inspiratory volume.

[0032] This method includes calculating the inspiratory volume of the gas discharged by one or more nozzles by time-integrating the measured flow rate, calculating the inspiratory volume of the intake air by time-integrating the intake flow rate, which is the difference between the total flow rate obtained by calculation and the measured flow rate, and calculating the inhaled oxygen of the patient based on the inspiratory volume of the gas discharged from one or more nozzles and the inspiratory volume of the intake air. Concentration( %FiO 2 ) It may further include calculating the %FiO obtained by calculation. The signal transmission may be based on the %FiO obtained by calculation. 2

[0033] Another aspect of the embodiments of the present disclosure is a non-transitory program storage medium storing instructions executable by a processor or a programmable circuit to perform operations for controlling an oxygen concentrator based on the total flow rate of the gas sent to the patient and the intake air by a ventilator. These operations may include measuring the flow rate of the gas discharged by one or more nozzles of a patient ventilation interface connected to the ventilator, measuring the pressure inside the patient ventilation interface, and calculating the total flow rate based on the measured flow rate and the measured pressure.

[0034] Another aspect of the embodiments of the present disclosure is a ventilator including the above non-transitory program storage medium, a processor or a programmable circuit for executing instructions, a flow sensor, and a pressure sensor. Measuring the flow rate may include communicating with the flow sensor, and measuring the pressure may include communicating with the pressure sensor.

[0035] Another aspect of the embodiments of the present disclosure is a ventilation system including the above ventilator and an oxygen concentrator connected to the ventilator. The operations may further include transmitting a signal from the ventilator to the oxygen concentrator based on the total flow rate obtained by calculation.

[0036] ​The oxygen concentrator may include a controller operable to generate a control signal in response to a signal transmitted from a ventilator, and the control signal generated by the controller selectively enables the inflow of pressurized ambient air into the product tank of the oxygen concentrator. The control signal generated by the controller operates the valve unit of the oxygen concentrator and can maintain a preset oxygen concentration in the product tank according to a signal transmitted from a ventilation device. The control signal generated by the controller operates the valve unit and can enable the flow of pressurized ambient air to bypass one or more sieve beds of the oxygen concentrator. The control signal generated by the controller operates the compressor of the oxygen concentrator and can maintain a preset oxygen concentration in the product tank according to a signal transmitted from a ventilator. The control signal generated by the controller operates a compressor external to the oxygen concentrator and can maintain a preset oxygen concentration in the product tank according to a signal transmitted from a ventilator.

[0037] Another aspect of an embodiment of the present disclosure is a method for controlling an oxygen concentrator to meet a patient's ventilation and oxygen supplementation needs at multiple activity levels of the patient. The method may include transitioning the oxygen concentrator to a first configuration in which a first portion of ambient air mixes with the concentrated oxygen gas output by one or more sieve beds of the oxygen concentrator to generate a concentrator output at a first flow rate that is a first oxygen concentration. The method may further include transitioning the oxygen concentrator to a second configuration in which a second portion of ambient air mixes with the concentrated oxygen gas output by one or more sieve beds to generate a concentrator output at a second flow rate that is a second oxygen concentration. The second flow rate is greater than the first flow rate, and the second oxygen concentration is lower than the first oxygen concentration.

[0038] Another aspect of embodiments of the present disclosure is a method for estimating the total flow rate of gas and intake air sent to a patient by a ventilator. The method includes, for each of a plurality of measurements of the flow rate of gas discharged by one or more nozzles of a patient ventilation interface connected to the ventilator, storing a plurality of measurements of the total flow rate corresponding to a plurality of measurements of the pressure within the patient ventilation interface, measuring the flow rate of gas discharged from the one or more nozzles, measuring the pressure within the patient ventilation interface, and estimating the total flow rate based on a comparison result between the measured pressure and the plurality of measurements of the total flow rate stored for the measured flow rate.

[0039] The method may further include transmitting a signal to an oxygen concentrator based on the estimated total flow rate.

[0040] The method may further include, based on the percentage of oxygen contained in the gas discharged by the one or more nozzles and the estimated total flow rate, the inhaled oxygen of the patient Concentration( %FiO 2 ) to calculate. The method may further include transmitting a signal to an oxygen concentrator based on the calculated %FiO 2 .

[0041] Another aspect of embodiments of the present disclosure is the inhaled oxygen of a patient receiving ventilation assistance from a ventilator Concentration( %FiO 2 ) to estimate. The method includes, for each of a plurality of measurements of the flow rate of gas discharged by one or more nozzles of a patient ventilation interface connected to the ventilator, storing a plurality of measurements of %FiO 2 corresponding to a plurality of measurements of the pressure within the patient ventilation interface, measuring the flow rate of gas discharged from the one or more nozzles, measuring the pressure within the patient ventilation interface, and, based on a comparison result between the measured pressure and the plurality of measurements of %FiO 2 stored for the measured flow rate, the %FiO of the patient 2may include estimating.

[0042] This method may further include transmitting a signal to the oxygen concentrator based on the estimated %FiO 2

Brief Description of the Drawings

[0043] The above-described features, advantages, and other features and advantages of the various embodiments disclosed herein will be better understood with reference to the following description and drawings. In the drawings, like numbers indicate like parts throughout.

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[0044] The present disclosure encompasses various embodiments of oxygen concentrators, ventilators, and their control systems and methods. The detailed description set forth below in connection with the appended drawings is intended as a description of presently contemplated embodiments and is not intended to represent the only form in which the disclosed invention may be developed or utilized. This description describes the functions and features associated with the illustrated embodiments. However, it will be understood that different embodiments, also intended to be encompassed by the scope of the present disclosure, may achieve the same or equivalent functions. Further, relative terms such as first, second, etc. are used only to distinguish one entity from another and do not necessarily require or imply any actual such relationship or order between such entities.

[0045] FIG. 1 shows an exemplary oxygen concentrator 100 according to an embodiment of the present disclosure. As shown, a ventilator 200 is configured to send the high-oxygen-concentration gas produced by the oxygen concentrator 100 to a patient 13 via a patient ventilation interface 12. For example, depending on various factors including a prescription for the patient 13, the patient's activity level, user-adjustable settings, and the patient's respiratory state at a given moment, the ventilator 200 can command the oxygen concentrator 100 to produce a gas with a specific oxygen concentration at a specific flow rate (e.g., volumetric flow rate). Moreover, the ventilator 200 enables the patient 13 to obtain assistance with breathing to the desired degree and achieve the target %FiO 2While considering that ambient air is further drawn into the patient ventilation interface 12 so as to obtain the gas, the gas with a high oxygen concentration as described above is provided to the patient 13 via the patient ventilation interface 12.

[0046] Generally, to create a gas with a high oxygen concentration from ambient air, the ambient air is pumped by a compressor 110 of an oxygen concentrator 100 through one or more adsorbent sieve beds 120 that remove nitrogen from pressurized air. The obtained gas with a high oxygen concentration (e.g., >90%) flows into a product tank 130 for feeding to a ventilator 200. More specifically, the controller 140 of the oxygen concentrator 100 can control a valve unit 150 to periodically pressurize the ambient air and send it to the sieve bed 120, and discharge the nitrogen waste extracted by the sieve bed. As shown in FIG. 1, for example, two sieve beds 120 (e.g., sieve bed A and sieve bed B) with opposite operating cycles can be provided, such that while sieve bed B discharges nitrogen to the atmosphere, sieve bed A fills the product tank 130 with a gas having a high oxygen concentration, and vice versa.

[0047] In the present disclosure, various ways of modifying and / or supplementing such a process are contemplated to finely adjust the oxygen concentrator 100 to create a desired gas flow at a specific oxygen concentration. Such an oxygen concentrator 100 can be used in combination with a ventilator 200 to meet the changing needs of the patient 13 in real time.

[0048] Referring more specifically to the arrangement of the conduits and valves of the valve unit 150, in the exemplary oxygen concentrator 100 of FIG. 1, a first sieve bed flow path 160a from the compressor 110 to the inlet of the sieve bed A via the valve V of the valve unit 150, and the valve V of the valve unit 150 1 via the valve V of the valve unit 150 to the inlet of the sieve bed A from the compressor 110, and the valve V of the valve unit 150 3It can be seen that a second sieve bed flow path 160b is provided that leads from the compressor 110 to the inlet of the sieve bed B via the [path not specified in the original]. In addition to these sieve bed flow paths 160a and 160b, the oxygen concentrator 100 has a valve V of a valve unit 150 that bypasses one or more sieve beds 120 6 also includes a bypass flow path 170 that leads from the compressor 110 to the product tank 130 via the [path not specified in the original]. Valve V 6 By controlling, the controller 140 can cause the pressurized ambient air from the compressor 110 to flow directly into the product tank without first passing through the sieve bed 120. Such ambient air eliminates the pressure drop associated with the sieve bed 120, but this can be mixed with the high-oxygen-concentration gas output from the sieve bed 120 in the product tank 130. When the ambient air and the output of the sieve bed are mixed, the volume fraction of the ambient air flowing through the bypass flow path 170 is added, so that the mixture accumulates in the product tank 130 in a shorter time than if only the sieve bed 120 filled the product tank 130, but at the same time, the oxygen concentration also decreases. By appropriately controlling the valve unit 150, the controller 140 can selectively control the flow rate to the product tank 130 and the oxygen concentration of the resulting product gas to meet the demand at the ventilator 200.

[0049] For example, in order to achieve an oxygen concentration of 93%, a compressor of a conventional oxygen concentrator without a bypass flow path 170 may have to generate a flow about 10 times the amount required at the output of the oxygen concentrator. That is, to produce 2 L / min of oxygen, a 2 L / min oxygen concentrator may have to generate 20 L / min of compressed gas. By using the bypass flow path 170, the oxygen concentrator 100 of the present disclosure can make the concentration of the oxygen to be sent and the continuous flow (e.g., minute ventilation) that the oxygen concentrator 100 can send be in a trade-off relationship with each other. For example, instead of supplying a flow of 2 L / min, the oxygen concentrator 100 may be set to supply a flow of 3.8 L / min with 1.8 L / min of oxygen (via the sieve bed 120) and 2 L / min of ambient air (via the bypass valve 170). The oxygen concentration of the supplied gas decreases to about 60%, but the total flow increases to 3.8 L / min. In this way, the oxygen concentrator 100 uses a downstream ventilator 200 that amplifies a flow of 3.8 L / min using the intake air at a ratio of about 3:1 to supply a gas with a minute ventilation volume of 11.4 L / min (3 × 3.8) at FiO 2 of about 32%. For comparison, when supplying a gas with 93% oxygen at 2 L / min, the gas sent from the oxygen concentrator 100 amplified by the ventilator 200 is only 6 L / min (3 × 2), but the FiO 2 of the gas supplied to the patient 13 becomes 50%. The oxygen concentrator 100 can produce up to 20 L / min of air (completely bypassing the sieve bed 120), and then this is adjusted by the ventilator 200 to FiO 2It can be amplified to 60 L / min (20×3) at approximately 21% (oxygen concentration in ambient air). As a result, it may be possible to meet the minute-level requirements of highly active patients 13 with a small oxygen concentrator 100. As the patient's activity level increases, it may be better to increase the ventilation volume and reduce the oxygen supply amount rather than increasing the oxygen supply amount. By using the bypass flow path 170, the total gas output can be varied, for example, between 2 L / min and 20 L / min by the oxygen concentrator 100, and accordingly, the oxygen concentration can also be changed from approximately 93% to approximately 21%. In this way, the oxygen concentrator 100 can have the functions of both a compressor and an oxygen concentrator, and as will be described later, the optimal amount setting level can be controlled by the ventilator 200.

[0050] The controller 140 can control the valve unit 150 by generating a control signal for controlling the individual valves (for example, V 1 ~V 6 ) of the valve unit 150. For example, in response to a command issued by the ventilator 200, the control signal may be generated. In this case, in a master / slave configuration in which the ventilator 200 functions as a master and the controller 140 or the oxygen concentrator 100 functions as a slave, the valve unit 150 may be controlled. The ventilator 200 can derive set points for the flow rate and / or oxygen concentration (based on inputs such as, for example, the prescription of the patient 13, the patient's activity level, user-adjustable settings, the respiratory state of the patient measured by the ventilator 200, etc.), and the controller 140 can appropriately generate a control signal to achieve that set point. When generating the control signal, the controller 140 can further take into account the measurement results of the pressure sensor 180 and / or the oxygen concentration sensor 190 fluidly connected to the outlet of the product tank 130. Such measurement results may be fed back to the controller 140 and used as additional inputs together with the set point from the ventilator 200. The controller 140 can function, for example, as a proportional-integral-derivative (PID) controller or implement other known control loop feedback mechanisms.

[0051] FIG. 2 shows an exemplary control signal for controlling the valve unit 150 when the bypass passage 170 includes an ON / OFF valve V 6 In the example of FIG. 2, the valve unit 150 is controlled such that compressed air from the compressor 110 passes through the sieve bed A in the first stage, passes through the sieve bed B in the second stage, and in the third stage, directly to the product tank 130 through the bypass passage 170 via the ON / OFF valve V 6 is sent. That is, it is controlled to perform a three-stage cycle.

[0052] FIG. 3 shows an exemplary control signal for controlling the valve unit 150 when the bypass passage 170 includes a proportional valve V 6 In the example of FIG. 3, the valve unit 150 is controlled to perform a two-stage cycle in which compressed air from the compressor 110 passes through the sieve bed A in the first stage and passes through the sieve bed B in the second stage, and during that time, the proportional valve V 6 is controlled so that a part of the compressed air can be selectively sent directly to the product tank 130 via the bypass passage 170.

[0053] In the examples described in connection with FIGS. 1-3, the bypass passage 170 directly connects the product tank 130 and the compressor 110. That is, the product tank 130 is directly connected to one compressor 110 that is fluidly connected to a plurality of sieve beds 120. However, the subject matter disclosed herein is not intended to be so limited. For example, instead of as described above, the bypass passage 170 may extend from a separate dedicated bypass compressor different from the compressor 110. To selectively permit the flow from the dedicated bypass compressor to the product tank 130 and achieve the same effect as the valve V of the valve unit 150, according to the control signal generated by the controller 140, such a dedicated bypass compressor may be switched on and off, or the output (e.g., rpm) of the dedicated compressor may be adjusted. When controlling the dedicated bypass compressor in this way, the valve V 6 ​6 It may be omitted. The dedicated bypass compressor may be included in the housing of the oxygen concentrator 100, or may be a separate additional component whose output is connected to the bypass flow path 170 of the oxygen concentrator 100 via a dedicated connector.

[0054] FIG. 4 shows an example of an oxygen concentrator 400 for use in combination with a dedicated bypass compressor that is a separate additional component as described above. The oxygen concentrator 400 may be the same as the oxygen concentrator 100 described in connection with FIG. 1, and may include a compressor 110, a sieve bed 120, a product tank 130, a controller 140, a valve unit 150, sieve bed flow paths 160a, 160b, a bypass flow path 170, a pressure sensor 180, and an oxygen concentration sensor 190, with the following differences: similar compressor 410, sieve bed 420, product tank 430, controller 440, valve unit 450, sieve bed flow paths 460a, 460b, bypass flow path 470, pressure sensor 480, and oxygen concentration sensor 490. The bypass flow path 170 in FIG. 1 extends from the compressor 110 to the product tank 130, but the bypass flow path 470 in FIG. 4 does not extend from the compressor 410 to the product tank 430, but extends from an external compressor fluid port 472 to the product tank 430. Further, in the valve unit 450, the valve V 6 of the valve unit 150 is omitted, and the control signal generated by the controller 440 is used to control an external bypass compressor via an external compressor signal port 474. As described above, in order to achieve the same effect as the valve V 6 such an external bypass compressor may be switched on and off according to the control signal, or the output of the external compressor may be adjusted.

[0055] FIG. 5 shows an exemplary modular system 500 including an oxygen concentrator module 510 and a compressor module 520. The oxygen concentrator module 510 is the oxygen concentrator 400 of FIG. 4 (e.g., 0 to 2 liters / min of O 2or can accommodate air provided at 0 to 20 liters per minute at 20 to 30 PSI and having a battery in the range of 100 Wh for 1 to 2 hours), and the compressor module 520 can accommodate an external compressor (e.g., providing air at 0 to 10 liters per minute at 20 to 30 PSI and having a battery in the range of 100 Wh for 2 to 3 hours). As indicated by the large arrows above and below the modular system 500, the oxygen concentrator module 510 and the compressor module 520 can be removably attached to form a single unit. For example, the user can slide the two modules 510, 520 together in the direction of the arrows, and lock the two modules 510, 520 together as one unit with the external compressor fluid port 472 of the oxygen concentrator module 510 being fluidly connected to the compressed gas output of the compressor module 520 and the external compressor signal port 474 of the oxygen concentrator module 510 being electrically connected to the signal input port of the compressor module 520. Sliding the two modules 510, 520 in the opposite direction unlocks and separates the modules 510, 520, making these modules available for separate use. In this way, patients who only need oxygen therapy can use the oxygen concentrator module 510, patients who only need mechanical ventilation can use the compressor module 520, and people who need both oxygen and mechanical ventilation can use the two units in combination. Also, it is conceivable that the upper part of the oxygen concentrator module 510 or the upper part of the compressor module 520 (or the combined surface formed by the upper parts of both the oxygen concentrator module 510 and the compressor module 520) can function as a cradle for docking the ventilator 200. Similarly, the bottom part of the oxygen concentrator module 510 or the bottom part of the compressor module 520 (or the combined surface formed by the bottom parts of both the oxygen concentrator module 510 and the compressor module 520) can function as an attachment for an auxiliary battery pack.

[0056] FIG. 6 shows another exemplary modular system 600 that includes an oxygen concentrator module 610. The oxygen concentrator module 610 can house the oxygen concentrator 100 of FIG. 1 or the oxygen concentrator module 400 of FIG. 4. As shown, in the modular system 600, an option exists to connect a live-line pluggable auxiliary battery pack 620 and / or a continuous positive airway pressure (CPAP) module 630 (e.g., with a 22 mm ISO tapered connector for CPAP) to the oxygen concentrator module 610, further enhancing modularity. For example, the top of the oxygen concentrator 610 can be made to function as a cradle for attaching the CPAP module 630, and this may include a latch release and electrical contacts. Similarly, the bottom of the oxygen concentrator 610 can be made to function as a cradle for attaching the battery pack 620, and this may include a latch release and electrical contacts. The oxygen concentrator module 610 may further include a DISS or quick connect, as well as a user interface that includes, for example, an ON / OFF button, a battery power indicator, and a wireless ventilator connection for the ventilator 200. Such modularity may be an alternative to, or in addition to, the attachment to an external compressor module 520 as described in relation to the modular system 500 of FIG. 5.

[0057] In the examples of the oxygen concentrators 100, 400, 510, and 610 described above, the bypass flow paths 170, 470 that bypass the sieve beds 120, 420 of the oxygen concentrators 100, 400, 510, 610 enable selective control of the flow rate to the product tanks 130, 430 and the oxygen concentration of the resulting product gas. However, the present disclosure is not intended to be so limited. For example, the timing of the valves of an oxygen concentrator configured conventionally in another way can be deliberately "disturbed" by the controllers 140, 440. Generally, the timing of the valves of an oxygen concentrator is set to an optimal amount so as to most efficiently extract oxygen in the sieve bed. By controlling the compressors 110, 410 and / or the valve units 150, 450 to change the timing of the sieve bed cycle, the controllers 140, 440 can intentionally prevent a situation where there is enough time for oxygen and nitrogen to be completely separated in the sieve beds 120, 420. As a result, it is possible to fill the product tanks 130, 430 with product gas having a reduced oxygen concentration, and potentially increase the flow rate of the product gas sent to the downstream ventilator 200. The controllers 140, 440 refer to, for example, a look-up table of sub-optimal compressor output and valve control timing where the separation of oxygen and nitrogen in the sieve beds 120, 420 is not the most efficient. Using such a look-up table, the controllers 140, 440 can generate a control signal in response to a command issued by the ventilator 200 and satisfy the changing needs of the patient 13 in real time. In this case, the bypass flow paths 170, 470 and valve V 6 may be omitted.

[0058] FIG. 7 shows an exemplary ventilation system 700 according to an embodiment of the present disclosure. As shown, the ventilation system 700 can include a patient ventilation interface 12 and a ventilator 200 arranged in a state where fluid flows between the patient 13 as shown in FIGS. 1 and 4, together with any one of the oxygen concentrators 100, 400, 510, 610 described in relation to FIGS. 1, 4, 5, and 6. The ventilator 200 may be configured to send the high-oxygen-concentration gas produced by the oxygen concentrators 100, 400, 510, 610 to the patient 13 via the patient ventilation interface 12. The patient ventilation interface 12 may include a device such as a full-face mask or a nasal mask that can be arranged so that gas flows directly between the upper airway of the patient 13, i.e., the nasal cavity and / or oral cavity. The patient ventilation interface 12 can be characterized by one or more nozzles 15 for sending the high-oxygen-concentration gas to the patient 13, in addition to one or more openings for taking in additional ambient air for sending to the patient 13. Examples of the patient ventilation interface 12 having the nozzles 15 and intake openings that can be used in the subject matter disclosed herein can be found, for example, in U.S. Patent Application Publication No. 2019 / 0099570, filed under the title "PATIENT INTERFACE WITH INTEGRATED JET PUMP", and the entire disclosure of the application is incorporated herein by reference. These examples can include, for example, the Engage, Inspire, and Universal Circuit (trademark) Connector (UCC) patient interface of the Life2000 (registered trademark) ventilation system of Breathe Technologies, Inc. At any moment, the total flow rate (e.g., volume flow rate) Q T of the gas sent to the patient 13 by the ventilator 200 and the intake air is defined as the sum of the nozzle flow rate Q N of the gas discharged by one or more nozzles 15 of the patient ventilation interface 12 and the intake flow rate Q E of the ambient air taken in by one or more nozzles 15. That is, the total flow rate Q T is QT =Q N +Q E can be defined as. In the case of the Life2000 (registered trademark) ventilation system, the flow rate Q N can be 5 to 40 L / min, and this can be maintained, for example, for a duration of up to 3.0 seconds.

[0059] For example, depending on various factors including the prescription for patient 13, the patient's activity level, user-adjustable settings, and the patient's respiratory state at a given moment, when ambient air is sent more or less proportionally to the high-oxygen-concentration gas discharged from one or more nozzles 15, the intake flow Q E (and as a result, the total flow Q T ) fluctuates, thereby causing a fluctuation in the patient's inhaled oxygen Concentration( %FiO 2 ) There may be a case where it fluctuates. By measuring the flow rate Q N of the gas discharged by one or more nozzles 15 and the pressure inside the patient ventilation interface 12, the ventilator 200 can calculate or estimate the total flow Q T . The ventilator 200 can instruct the oxygen concentrators 100, 400, 510, 610 to create a specific gas flow at a specific oxygen concentration according to the estimated or calculated total flow Q T . Then, the ventilator 200 provides such a high-oxygen-concentration gas to the patient 13 via the patient ventilation interface 12, taking into account that ambient air is further drawn into the patient ventilation interface 12 so that the patient 13 can obtain assistance for the breathing operation to the desired degree and obtain the gas at the target %FiO 2 .

[0060] The ventilator 200 can include a first inlet port 16 through which the high-oxygen-concentration gas supplied to the ventilator 200 by the oxygen concentrators 100, 400, 510, 610 passes. This first inlet port 16 can be in communication with an inlet filter 24 that removes particles and other contaminants from the breathing gas ultimately sent to the patient. The pressure of the high-oxygen-concentration gas from the oxygen concentrators 100, 400, 510, 610 can be adjusted by a valve 26. The valve 26 has a valve inlet port 26a through which gas flows in communication with the inlet filter 24 of the ventilator 200 and a valve outlet port 26b through which gas flows in communication with an outlet port 28. The state of the valve 26 can be selectively adjusted so that gas of a desired volume / pressure flows from the oxygen concentrators 100, 400, 510, 610 to the patient 13. The operation of the valve 26 can be controlled by a controller 30 that implements various methods contemplated by the present disclosure, as will be described in more detail below.

[0061] The flow of breathing gas through the valve 26 can be sent through the outlet port 28 to a gas transport tube 32 connected to the patient ventilation interface 12 described above. The gas transport tube 32 can be, for example, a plastic tube having a predetermined inner diameter such as 22 mm or less. Depending on the breathing state of the patient 13, a pressure difference may occur between the patient ventilation interface 12 and the output of the valve 26, i.e., the valve outlet 26b.

[0062] To confirm such a pressure difference, the ventilation system 700 can include a dual pressure sensor including a valve pressure sensor 34 and a patient interface pressure sensor 36. For the valve pressure sensor 34, it can be arranged inside the ventilator 200, and this sensor can monitor the pressure at the outlet port 26b of the valve. The patient interface pressure sensor 36 can also be physically arranged inside the ventilator 200, but it is in a state where gas can flow directly to and from the patient ventilation interface 12 via a pressure sensor line 38 connected to the sensor inlet port 40 of the ventilator 200. When the ventilator 200 is operating, the gas pressure in the pressure sensor line 38 and the gas conduit 32 can be connected, and a purge flow for cleaning the pressure sensor line 38 can be sent out. This can be done via a purge solenoid 42 connected to both. The purge can be continuous or intermittent depending on the patient's breathing phase or the pressure difference between the valve pressure and the patient interface pressure.

[0063] In addition to measuring the pressure difference between the patient ventilation interface 12 and the valve output 26b, the measured value of the flow rate of the breathing gas actually output from the valve 26 can be utilized. For this purpose, the ventilator 200 may include a flow sensor 43 in-line with the valve 26 and the outlet port 28.

[0064] The ventilator 200 can measure the pressure inside the patient ventilation interface 12 and the flow rate of the gas discharged by one or more nozzles 15 of the patient ventilation interface 12. For example, the controller 30 can communicate with one or both of the valve pressure sensor 34 and the patient interface pressure sensor 36 to measure the pressure, and can communicate with the flow sensor 43 to measure the flow rate. As will be described in detail later, based on the actually measured pressure and flow rate, the controller 30 determines the total flow rate Q Tand / or other various parameters can be estimated or calculated. For this purpose, the ventilator 200 can further include a nozzle data storage unit 31 capable of storing one or more constants associated with each of a plurality of nozzle shapes. During use, the controller 30, based on the measured flow rate, measured pressure, and one or more constants stored in relation to the nozzle shape of one or more nozzles 15, can calculate the total flow rate Q T The calculated total flow rate Q T Based on this, the controller 30 can further calculate the patient's %FiO 2 When the user-adjustable settings of the ventilator 200 are changed (for example, using inputs 69 such as a touch screen or buttons and outputs 62 such as a display), the controller 30 can continuously calculate the total flow rate Q T and / or the patient's %FiO 2 in real time as changes in the user's activity level and breathing.

[0065] Based on the calculated total flow rate Q T and / or the patient's %FiO 2 the controller 30 can, for example, send a signal (e.g., a radio frequency wireless signal) from the ventilator 200 to the oxygen concentrators 100, 400, 510, 610 to issue commands to the oxygen concentrators 100, 400, 510, 610. Upon receiving the signal from the ventilator 200, the oxygen concentrators 100, 400, 510, 610 can adjust the pressure, flow rate, and / or oxygen concentration of the high-oxygen-concentration gas generated to meet the changing needs of the patient in real time. Such adjustments can be made within the oxygen concentrators 100, 400, 510, 610 as described above in relation to FIGS. 1 and 4. In this way, the ventilator 200 can control the oxygen concentrators 100, 400, 510, 610 in a master / slave configuration where the ventilator 200 functions as the master and the oxygen concentrators 100, 400, 510, 610 function as slaves.

[0066] Figure 8 shows an exemplary operation flow that can be executed in whole or in part by a ventilator 200 according to one embodiment of the subject matter disclosed herein. Using the operation flow of Figure 8, the measured flow rate Q of the gas discharged by one or more nozzles 15 N (nozzle flow rate) and the measured pressure P of the patient ventilation interface 12 aw (intratracheal pressure), the total flow rate Q T can be calculated. Similarly, if the flow rate Q of the gas discharged by one or more nozzles 15 is known, using the operation flow of Figure 8, the intake flow rate Q N caused by the flow rate Q passing through the nozzle 15 N can be calculated, as well as various other values that can be derived therefrom. E =Q T -Q N In general, the intake is affected by the pressure downstream of the nozzle. In the case of the nozzle 15 of the patient ventilation interface 12 such as the nozzle of the Life2000 (registered trademark) system, this pressure can be regarded as the measured pressure P

[0067] . When the pressure P aw reaches the stagnation point pressure P aw , due to the back pressure of the patient's airway and lungs, the flow rate Q S through the nozzle 15 becomes 0. Using this stagnation point pressure P N , according to the following formula, the total flow rate Q S can be calculated as a function of Q N and P aw . T [Equation] Here, the stagnation point pressure P S is a function of the flow rate Q of the discharged gas and can be calculated as the following quadratic equation. N [Equation] [Equation] ​a, b, and c are constants that depend on the specific nozzle shape. For the constants a, b, and c, they can be determined in advance for each nozzle shape by finding the stagnation point pressure at a given flow rate. In the case of the UCC patient interface of the Life2000 (registered trademark) system, with a = 0.0191 and b = 0.3828, the pressure P at the stagnation point pressure aw and the nozzle flow rate Q N The relationship shown in FIG. 9 can be obtained by calculation. Specifically, the stagnation point pressure P as a function of the nozzle flow rate Q N , that is, P S , namely P S (Q N ) is obtained. In the case of the UCC patient interface, c = 8, and for each of a plurality of nozzle flow rates Q N (5, 10, 20, 30, 40 L / min), the relationship shown in FIG. 10 can be obtained by calculation between the total flow rate Q T and the pressure P aw .

[0068] Regarding the operation flow of FIG. 8, it can start with a step 802 of storing one or more constants in relation to each of a plurality of nozzle shapes. For example, the above constants a, b, and c can be stored for each of a plurality of nozzle shapes according to the Engage, Inspire, and UCC patient interfaces of the Life2000 (registered trademark) system. For example, these constants may be stored in the nozzle data storage unit 31 shown in FIG. 7. Alternatively, the constants may be stored in the patient ventilation interface 12 itself, such as in a memory (e.g., EEPROM) arranged in the harness of the patient ventilation interface 12. In that case, the constants a, b, and c related to each specific nozzle shape can be stored in the patient ventilation interface 12. Thereby, each nozzle can be calibrated separately from the ventilator 200 to clarify the manufacturing differences between the nozzles.

[0069] During the treatment of the patient 13 using the ventilation system 700, the operation flow of FIG. 8 is based on the flow rate Q of the gas discharged from one or more nozzles 15 of the patient ventilation interface 12 NStep 804 of measuring, and the pressure P within the patient ventilation interface 12 aw can be continued with step 806 of measuring the pressure P aw . Measuring the pressure P can include communication between the controller 30 and both the valve pressure sensor 34 and the patient interface pressure sensor 36. For example, the measured pressure P aw can be defined as the difference between the pressure of the patient ventilation interface 12 measured by the patient interface pressure sensor 36 and the pressure of the valve outlet port 26b measured by the valve pressure sensor 34. Once the measured flow rate Q N and the measured pressure P aw are obtained, the operation flow can be continued with step 808 of calculating the total flow rate Q of the gas and intake air sent to the patient 13 by the ventilator 200. For example, the controller 30, based on the measured flow rate Q T and the measured pressure P N , and the stored constants a, b, and c, uses the above formula to, for example, calculate the stagnation point pressure P aw . For the calculation of the stagnation point pressure P S , the constants a and b and the measured flow rate Q N are used, and then, for the calculation of the total flow rate Q T , the measured flow rate Q N , the measured pressure P aw , the stagnation point pressure P S and the constant c are used to calculate the total flow rate Q T . When calculating the total flow rate Q T , the controller 30 can read the constants a, b, c from the nozzle data storage unit 31, and if the constants are stored in the memory of the patient ventilation interface 12, the controller 30 can read the constants a, b, c from the external memory when connecting the patient ventilation interface 12 to the ventilator 200 (for example, via a smart connector that downloads the constants to the ventilator 200).

[0070] In step 810, various values that can be derived from the total flow rate Q T , such as one or more tidal volumes, can be calculated. For example, the total flow rate Q TAs the time integral, the total inspiratory volume TotV t can be calculated, and as the time integral of the actually measured flow rate Q N the inspiratory volume NozV of the gas discharged by one or more nozzles 15 t can be calculated and / or the intake flow rate Q E =Q T -Q N as the time integral, the inspiratory volume EntV of the intake air t can be calculated. In step 812, the controller 30 can calculate %FiO 2 based on the inspiratory volume of the gas discharged by one or more nozzles 15 and the inspiratory volume of the intake air. For example, assuming that the gas discharged from one or more nozzles 15 is 100% oxygen, %FiO 2 can be calculated as %FiO 2 =100(NozV t +0.21 EntV t ) / TotV t Here, 21% is approximately the proportion of oxygen contained in the ambient atmosphere. More generally, (for example, when the oxygen concentrators 100, 400, 510, 610 are controlled to supply a gas with a low oxygen concentration as described above) for any gas discharged by one or more nozzles 15, %FiO 2 can be calculated as %FiO 2 =100(NozV t +0.21 EntV t ) / TotV t Here, 100X is the percentage of oxygen contained in the gas discharged by one or more nozzles 15. The value X that defines the oxygen concentration of the gas discharged by one or more nozzles 15 can be determined from the known oxygen concentration of the gas supplied from the oxygen concentrators 100, 400, 510, 610, based on, for example, the current / previous set points issued by the controller 30 and / or the measurement results of the oxygen concentration sensor 190.

[0071] Finally, in step 814, the controller 30 of the ventilator 200 causes the ventilator 200 to transmit signals to the oxygen concentrators 100, 400, 510, 610, for example, as described above, to obtain the total flow rate Q determined by calculation T or %FiO 2 Based on this, commands can be given to the oxygen concentrators 100, 400, 510, 610. When receiving a signal from the ventilator 200, the oxygen concentrators 100, 400, 510, 610 adjust the pressure, flow rate, and / or oxygen concentration of the high-oxygen-concentration gas to be generated to the desired total flow rate Q T and / or %FiO 2 can be achieved.

[0072] In the above example, the constants a, b, c are stored for each nozzle shape. However, it is considered that it may be possible to store the stagnation point pressure P N for the possible flow rate range Q S and store only the constant c for each nozzle shape. If the ventilator 200 is designed to be used with only one nozzle shape, there is no need to store any constants, and step 802 can be omitted. Without changing the above formula for different nozzle shapes, the total flow rate Q N can be easily calculated as a function of the measured flow rate Q aw and the measured pressure P T .

[0073] Figure 9 shows an example of the stagnation point pressure of the nozzle calculated at different flow rates and the stagnation point pressure of the nozzle measured at different flow rates. As described above, the relationship obtained by the calculation shown in Figure 9 is obtained using the constants a = 0.191 and b = 0.3828 and the above formula for the stagnation point pressure P S . The other relationship shown in Figure 9 ("measured cmH2O") is the experimental result of measuring the stagnation point pressure P S of the UCC patient interface. As is clear from Figure 9, the measured relationship is almost the same as the relationship obtained by calculation, indicating that there is a quadratic relationship between the stagnation point pressure P S and the nozzle flow rate Q N .

[0074] Figure 10 shows the P aw -Q T curves calculated for different flow rates of the nozzle and the P aw -Q T curves measured for different flow rates. As described above, the relationship obtained from the calculations shown in Figure 10 is the total flow rate Q N as a function of the airway pressure P aw for a constant c = 8 and different nozzle flow rates Q T using the above equation. Other relationships ("Act-5", "Act-10", etc.) are for nozzle flow rates Q N of 5, 10, 20, 40 L / min for the total flow rate Q T and the actual experimental results of the measured relationship between the airway pressure P aw As is clear from Figure 10, the measured relationship is almost the same as the relationship obtained by calculation, indicating that there is a linear relationship between the airway pressure P aw and the total flow rate Q T .

[0075] Figure 11 shows another exemplary operation flow that can be executed in whole or in part by the ventilator 200 according to an embodiment of the subject matter disclosed herein. In the example of Figure 11, instead of calculating the total flow rate Q T using the relationship between the stagnation point pressure P S and the constants a, b, c, the characteristic P T -Q aw curves for a certain nozzle (or nozzles) are pre-stored, and the total flow rate Q T is calculated for the actually measured pressure P aw and the nozzle flow rate Q N T ​can be used for estimation. This operation flow can be started, for example, in step 1102 of storing the total flow rate data in the nozzle data storage unit 31 of the ventilator 200. As an example, the total flow rate data may include the characteristic curve of FIG. 10 for one or more nozzles (for example, the underlying data, which can be stored in tabular form or as a parameterized equation). The characteristic curve stored in advance, as in the case of storing constants a, b, and c, may be stored in the memory of each patient interface 12 that characterizes a specific patient interface 12. For a certain patient interface 12, in the nozzle data storage unit 31 or an external memory, the flow rate Q N of the gas discharged by one or more nozzles 15 of the patient ventilation interface 12 N for each of a plurality of measurement values (for example, as shown in FIG. 10, Q aw = 5, 10, 20, 30, 40), and the total flow rate Q N corresponding to a plurality of measurement values of the pressure P in the patient ventilation interface 12 can be stored.

[0076] During the treatment of patient 13 using the ventilation system 700, as described above, the operation flow of FIG. 11 is carried out from the flow rate Q N of the gas discharged from one or more nozzles 15 of the patient ventilation interface 12 in step 1104 of measuring, and in step 1106 of measuring the pressure P aw in the patient ventilation interface 12. It can be continued. When the measured flow rate Q N and the measured pressure P aw are obtained, based on the comparison result with the plurality of measurement values of the total flow rate Q aw stored for the measured pressure P N and the measured flow rate Q T , the operation flow can be continued in step 1108 of estimating the total flow rate Q T . For example, the controller 30 refers to the nozzle data storage unit 31 and examines the characteristic P aw -Q T curve shown in FIG. 10, and the characteristic P N corresponding to the measured flow rate Q aw -Q TFind the curve and, along that curve, the total flow rate Q aw corresponding to the measured pressure P T can be read.

[0077] As described above, once the total flow rate Q T is estimated, the operation flow of FIG. 11 can be continued with step 1110 of calculating any one of a plurality of single inspiration volumes or other various values that can be derived from the total flow rate Q T , step 1112 of calculating the %FiO 2 of patient 13, and step 1114 of transmitting a signal to oxygen concentrator 100. All of these steps can be executed in the same manner as steps 810, 812, and 814 of the operation flow of FIG. 8. The only difference is that in the case of FIG. 10, the total flow rate Q T is not calculated using the measured pressure P aw , the measured flow rate Q N , and one or more constants characterizing patient interface 12, but is estimated using a pre-stored characteristic curve. Upon receiving a signal from ventilator 200, oxygen concentrators 100, 400, 510, 610 can adjust the pressure, flow rate, and / or oxygen concentration of the high oxygen concentration gas generated to achieve the desired total flow rate Q T and / or %FiO 2 .

[0078] FIG. 12 shows another exemplary operation flow that can be executed in whole or in part by ventilator 200 according to one embodiment of the subject matter disclosed herein. In the example of FIG. 12, instead of estimating the total flow rate Q 2 prior to calculating the %FiO T of the patient, %FiO 2 data for each nozzle is pre-stored and can be used to estimate the %FiO aw for the measured pressure P N and the nozzle flow rate Q 2 . This operation flow can be started, for example, with step 1202 of storing %FiO 2 data in nozzle data storage unit 31 of ventilator 200. %FiO 2The data may include the characteristic curve of FIG. 10 for one or more nozzles (e.g., the underlying data, which can be stored in tabular form or as a parameterized equation). The pre-stored characteristic curve, as in the case of storing constants a, b, and c, may be stored in the memory of each patient interface 12 that characterizes a particular patient interface 12. For a particular patient interface 12, in the nozzle data storage unit 31 or an external memory, the flow rate Q of the gas discharged by one or more nozzles 15 of the patient ventilation interface 12 N for each of a plurality of measurements (e.g., as shown in FIG. 10, Q N = 5, 10, 20, 30, 40), the pressure P within the patient ventilation interface 12 aw a plurality of measurements corresponding to the plurality of measurements of %FiO 2 can be stored. Such a characteristic P aw -%FiO 2 curve can be experimentally obtained by measuring %FiO aw in a laboratory at various pressures P N and nozzle flow rates Q 2 , or can be derived from the total flow rate data described above with respect to the operation flow of FIG. 11.

[0079] During the treatment of patient 13 using the ventilation system 700, as described above, the operation flow of FIG. 12 can be continued with a step 1204 of measuring the flow rate Q of the gas discharged from one or more nozzles 15 of the patient ventilation interface 12 N and a step 1206 of measuring the pressure P within the patient ventilation interface 12 aw . Once the measured flow rate Q N and the measured pressure P aw are obtained, based on the comparison results with the plurality of measured values of FiO aw stored for the measured pressure P N and the measured flow rate Q 2 , the FiO of the patient 2In the step 1208 of estimating, the operation flow can continue. For example, the controller 30 refers to the nozzle data storage unit 31 to check the %FiO 2 data for one or more specific nozzles 15, and the measured flow rate Q N to find the characteristic P aw -%FiO 2 curve, and read the value of %FiO aw corresponding to the measured pressure P 2 along the curve. As described above, once the patient's %FiO 2 is estimated, in the step 1210 of sending a signal to the oxygen concentrator 100, the operation flow of FIG. 12 can continue. This step can be performed in the same manner as step 814 of FIG. 8 or step 1114 of FIG. 11. The only difference is that in the case of FIG. 12, %FiO 2 is directly estimated using a pre-stored characteristic curve instead of being calculated from the total flow rate Q T . When receiving a signal from the ventilator 200, the oxygen concentrators 100, 400, 510, 610 can adjust the pressure, flow rate, and / or oxygen concentration of the high oxygen concentration gas generated to achieve the desired intake ratio and / or %FiO 2 .

[0080] In the above exemplary operation flows of FIGS. 8, 11, and 12, the total flow rate Q T and / or the patient's %FiO 2 are calculated or estimated and used to characterize the needs of the patient 13 at a certain moment for the purpose of controlling the oxygen concentrator 100. However, the subject matter disclosed herein is not intended to be limited to these specific parameters. For example, alternative parameters such as the intake flow Q E , the intake ratio η = (Q T -Q N ) / Q N or the tidal volume TotV t , NozV t or EntV t and other related parameters that can be derived may be used instead. Using the subject matter disclosed herein, any such values can all be based on the measured airway pressure P of the patientaw and the nozzle flow rate Q N can be calculated and / or estimated based thereon.

[0081] The controllers 140 and 440 of the oxygen concentrators 100 and 400 and / or the controller 30 of the ventilator 200, and their respective functions, may be implemented by a programmable integrated circuit device such as a microcontroller or a control processor. Roughly speaking, this device can receive inputs and generate outputs based on those inputs. The specific operations performed on the inputs may be programmed as instructions executed by the control processor. In this regard, the device can include an arithmetic / logic unit (ALU), various registers, and input / output ports. An external memory such as an EEPROM (electrically erasable / programmable read-only memory) may be connected to the device to permanently store and retrieve program instructions, and there may be an internal random access memory (RAM). A computer program for implementing any of the disclosed functions of the controllers 140 and 440 and / or the controller 30 may be resident on such a non-transitory program storage medium as well as on a removable non-transitory program storage medium such as a semiconductor memory (e.g., an IC card) if, for example, it provides an update to an existing device. Examples of program instructions stored on a program storage medium or a computer-readable medium include, in addition to code executable by a processor, state information for execution by a programmable circuit such as a field programmable gate array (FPGA) or a programmable logic device (PLD).

[0082] The above description is presented by way of example and not limitation. Based on the above disclosure, those skilled in the art can devise variations that are within the spirit and scope of the invention disclosed herein. Further, the various features of the embodiments disclosed herein can be used alone or in various combinations and are not intended to be limited to the specific combinations described herein. Accordingly, the claims should not be limited by the exemplary embodiments shown.

Claims

1. A method for controlling an oxygen concentrator connected to a ventilator based on the inhaled oxygen concentration of a patient receiving ventilation assistance from the ventilator, comprising: for each of a plurality of measurements of the flow rate of the gas discharged by the one or more nozzles of a patient ventilation interface connected to the ventilator, which includes one or more openings for taking in additional ambient air for delivery to the patient in addition to the one or more nozzles, storing a respective data set including a plurality of measurements of the inhaled oxygen concentration corresponding to a plurality of measurements of the pressure within the patient ventilation interface; a flow sensor measuring the flow rate of the gas discharged from the one or more nozzles; a pressure sensor measuring the pressure within the patient ventilation interface; a controller estimating the inhaled oxygen concentration of the patient based on a comparison result between the pressure measured by the pressure sensor and the data set stored for the flow rate measured by the flow sensor.

2. The method according to claim 1, further comprising the controller transmitting a signal to the oxygen concentrator based on the estimated inhaled oxygen concentration.

3. further comprising storing one or more constants associated with each of the plurality of nozzle shapes, wherein the one or more nozzles have a nozzle shape corresponding to one of the plurality of nozzle shapes, and wherein estimating the inhaled oxygen concentration of the patient is further based on the one or more constants stored in relation to the nozzle shape of the one or more nozzles, according to the method of claim 1.

4. for each of the plurality of nozzle shapes, storing the associated one or more constants in a memory disposed in a patient ventilation interface having a nozzle with that nozzle shape, and wherein estimating the inhaled oxygen concentration of the patient includes reading the one or more constants stored in the patient ventilation interface connected to the ventilator, according to the method of claim 3.

5. A non-transitory program storage medium storing instructions executable by a processor or programmable circuit to perform operations for controlling an oxygen concentrator connected to a ventilator based on the inhaled oxygen concentration of a patient receiving ventilation assistance from the ventilator, wherein the operations are In addition to the one or more nozzles, each of the one or more nozzles of the patient ventilation interface connected to the ventilator, including one or more openings for taking in additional ambient air to be sent to the patient, stores a respective data set including a plurality of measured values of the inhaled oxygen concentration corresponding to a plurality of measured values of the pressure within the patient ventilation interface for each of the plurality of measured values of the flow rate of the gas discharged, measuring the flow rate of the gas discharged from the one or more nozzles with a flow rate sensor, measuring the pressure within the patient ventilation interface with a pressure sensor, A program storage medium including estimating the inhaled oxygen concentration of the patient based on a comparison result between the pressure measured by the pressure sensor and the data set stored for the flow rate measured by the flow rate sensor.

6. The non-transitory program storage medium according to claim 5, a processor or programmable circuit for executing the instructions, the flow rate sensor, including the pressure sensor, the measurement of the flow rate includes communicating with the flow rate sensor, A ventilator, wherein the measurement of the pressure includes communicating with the pressure sensor.

7. The ventilator according to claim 6, including an oxygen concentrator connected to the ventilator, the operation, A ventilation system further including transmitting a signal from the ventilator to the oxygen concentrator based on the estimated inhaled oxygen concentration.

8. The oxygen concentrator includes a controller operable to generate a control signal in response to the signal transmitted from the ventilator, and the control signal generated by the controller selectively enables the inflow of pressurized ambient air into the product tank of the oxygen concentrator. The ventilation system according to claim 7.

9. The control signal generated by the controller operates the valve unit of the oxygen concentrator to maintain a preset oxygen concentration within the product tank according to the signal transmitted from the ventilator. The ventilation system according to claim 8.

10. The control signal generated by the controller operates the valve unit to enable the flow of the pressurized ambient air to bypass one or more sieve beds of the oxygen concentrator. The ventilation system according to claim 9.

11. The control signal generated by the controller operates a compressor of the oxygen concentrator and maintains a preset oxygen concentration in the product tank according to the signal transmitted from the ventilator, the ventilation system according to claim 8.

12. The control signal generated by the controller operates a compressor outside the oxygen concentrator and maintains a preset oxygen concentration in the product tank according to the signal transmitted from the ventilator, the ventilation system according to claim 8.

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