Oxygen concentrator with sieve bed bypass and method of controlling the same

Abstract

An oxygen concentrator includes: one or more adsorption sieve beds operable to remove nitrogen from air to produce concentrated oxygen at their respective outlets; a product reservoir fluidly coupled to the respective outlets of the adsorption sieve beds; a compressor operable to pressurize ambient air; one or more sieve bed flow paths from the compressor to the respective inlets of the adsorption sieve beds; a bypass flow path from the compressor to the product reservoir, bypassing the adsorption sieve beds; and a valve unit operable to selectively allow pressurized ambient air from the compressor to flow along the one or more sieve bed flow paths and along the bypass flow path in response to a control signal. The valve unit can be controlled in response to commands issued by the ventilator based on a calculated or estimated total flow rate of gas and entrained air or the patient's %FiO2.

Description

background

[0001] 1. Technical Field of the Invention

[0002] This disclosure generally relates to oxygen concentrators, and more specifically, to an oxygen concentrator arranged to produce a gas with a high oxygen content, which is delivered to a patient via a ventilator.

[0003] 2. Description of related technologies

[0004] A wide range of clinical conditions may require some form of ventilation therapy, whereby a pressurized flow of gas from a ventilator to the patient's airway helps with the work of breathing. These conditions may include hypoxemia, various forms of respiratory failure, and airway dysfunction. There are also non-respiratory and non-airway conditions that require ventilation therapy, such as congestive heart failure and neuromuscular disorders.

[0005] To improve the quality of life for many patients requiring long-term ventilation, miniaturized and portable ventilation systems have been developed. Some of these systems (e.g., Breathe Technologies, Inc.) The systems are so lightweight and compact that patients can wear them in either their extended range or standalone configuration. These systems operate using a pressurized ventilation gas source. In fixed or extended range configurations, the compressed gas source can be a fixed compressor unit that can be stored in the patient's home. In standalone configurations, which are typically used when the patient is outside the home, portable wearable ventilators usually receive their breathing gases from a pressurized gas cylinder or a portable compressor.

[0006] Many of the aforementioned clinical conditions, and others, may require or benefit from supplemental oxygen therapy, which increases the amount of gas introduced into a patient's airway through the presence of additional oxygen, allowing the patient to inhale gas with an oxygen content higher than atmospheric concentration (20.9% at 0% humidity). Supplemental oxygen therapy involves the patient receiving supplemental oxygen from an oxygen source (usually a compressed or cryogenic oxygen cylinder, or an oxygen generator). For many years, patients wishing to move relied on oxygen cylinders. However, in recent years, the miniaturization and improvement of battery technology have led to the development of portable oxygen concentrators.

[0007] Portable oxygen concentrators typically operate using pressure swing adsorption (PSA), where ambient air is pressurized by a compressor and passed through an adsorption sieve bed. The sieve bed is usually formed of zeolite, which preferentially adsorbs nitrogen when oxygen passes through under high pressure. Once the sieve bed reaches its nitrogen adsorption capacity, the pressure can be reduced. This pressure reduction causes the adsorbed nitrogen to desorb, thus removing it and leaving a regenerated sieve bed ready to adsorb nitrogen again. Through repeated cycles of this operation, oxygen-enriched gas can be produced. Typically, portable oxygen concentrators have at least two sieve beds, so that one is operational while the other is removing and expelling nitrogen. Today, a typical portable oxygen concentrator outputs oxygen-enriched gas with an oxygen purity of approximately 87%–96%. Among the existing oxygen concentrators that can be considered portable today (especially for individuals with respiratory conditions), there are generally two types. The first type is larger and heavier, typically capable of continuous flow delivery. This type of model typically weighs between 5–10 kg, has a maximum flow rate of approximately 5–6 liters per minute or less, and is usually equipped with wheels and a handle, often mimicking the appearance of a suitcase. The second type is a lighter unit, more suitable for carrying or wearing in a shoulder bag, tote bag, or backpack. This type of model typically weighs less than 2.5 kg and is usually limited to pulse delivery with a maximum flow rate of about 2 liters per minute or less.

[0008] Portable oxygen concentrators offer substantial cost and convenience advantages over pressurized oxygen cylinders, which require constant refilling or replacement. Furthermore, portable oxygen concentrators are considered significantly safer than pressurized oxygen cylinders. This safety concern has a substantial impact on patients' quality of life, as many portable oxygen concentrators have been approved by the Federal Aviation Administration (FAA) for use by travelers on commercial airlines, while oxygen cylinders are generally prohibited on commercial flights. Therefore, patients carrying pressurized oxygen cylinders must make expensive and time-consuming preparations with airlines in advance, or cancel their air travel altogether.

[0009] For patients who do not require ventilatory support, supplemental oxygen therapy alone, without ventilatory support, may suffice. However, for many patients, combined ventilatory support and supplemental oxygen therapy may be a more desirable treatment approach. In healthy patients, adequate ventilation for ventilatory support typically requires a minute ventilation rate of 5–8 L / min at rest, which may double during mild exercise and exceed 40 L / min during vigorous exercise. Patients with respiratory conditions may require even higher rates and higher instantaneous ventilation rates. This is especially true when these patients are outside the home and require portability, as they often engage in mild exercise during these times.

[0010] Therefore, it can be seen that in many cases, existing portable oxygen concentrators cannot be used with wearable portable ventilators because they cannot deliver gas at sufficiently high pressures and / or volumes without an additional source of compressed gas. This significantly limits patients who wish to receive this combined therapy. Thus, when maximum portability is required, these patients must forgo the substantial benefits of portable oxygen concentrators and use oxygen cylinders (which can deliver oxygen at the higher pressures and flow rates required for ventilatory therapy), or they must carry a separate portable compressor, connecting the portable oxygen concentrator, portable compressor, and wearable ventilator together.

[0011] Existing systems and methods attempting to provide combined supplemental oxygen / ventilation systems are largely inadequate. For example, U.S. Patent Application Publications Nos. 2017 / 0340851 and 2018 / 0001048 describe adding an accumulator tank downstream of the product reservoir of an oxygen concentrator for the stated purpose of providing a more constant flow of product gas to a mechanical ventilator. U.S. Patent Application Publication No. 2017 / 0113013 describes using measurements of product reservoir pressure and output flow rate to determine whether the oxygen concentrator is fluidly connected to the ventilator (characterized by intermittent, spontaneous bursts of oxygen-enriched gas from the oxygen concentrator). If so, valves or pumps of the oxygen concentrator are controlled to increase or decrease the product reservoir pressure or gas flow rate to meet the ventilator's supply requirements. Such systems can generally be understood as designed only to meet the ventilator's process requirements, such as ensuring that the product reservoir pressure does not fall below a certain threshold. They are not capable of meeting the specific needs of patients receiving ventilatory therapy. Although U.S. Patent Application Publication No. 2017 / 0113013 envisions the determination of a patient status indicator, this determination is based solely on measurements performed within the concentrator and is only equivalent to a rough estimate. Summary of the Invention

[0012] This disclosure conceives of various systems, methods, and apparatuses to overcome the aforementioned disadvantages of the accompanying related art. One aspect of an embodiment of this disclosure is an oxygen concentrator comprising: one or more adsorption sieve beds operable to remove nitrogen from air to produce concentrated oxygen at their respective outlets; a product tank fluidly coupled to the respective outlets of the one or more adsorption sieve beds; a compressor operable to pressurize ambient air; one or more sieve bed flow paths from the compressor to the respective inlets of the one or more adsorption sieve beds; a bypass flow path from the compressor to the product tank, bypassing the one or more adsorption sieve beds; and a valve unit operable to selectively allow pressurized ambient air from the compressor to flow along the one or more sieve bed flow paths and along the bypass flow path in response to a control signal.

[0013] The valve unit may include one or more on / off valves, and the valve unit may selectively allow pressurized ambient air from the compressor to flow along one or more screen bed flow paths and along bypass flow paths by selectively adjusting the state timing of one or more on / off valves relative to the operating cycle of one or more adsorption screen beds.

[0014] The valve unit may include one or more proportional valves, and the valve unit may selectively allow pressurized ambient air from the compressor to flow along one or more screen bed flow paths and along the bypass flow path by selectively adjusting the input amount to one or more proportional valves. The valve unit may also selectively allow pressurized ambient air from the compressor to flow along one or more screen bed flow paths and along the bypass flow path by selectively adjusting the state timing of one or more proportional valves relative to the operating cycle of one or more adsorption screen beds.

[0015] The oxygen concentrator may also include a controller capable of generating control signals. The control signals generated by the controller can operate valve units to maintain a preset oxygen concentration in the product tank. The controller can generate control signals in response to commands from a ventilator fluidly connected to the outlet of the product tank.

[0016] Another aspect of the embodiments of this disclosure is a system including the aforementioned oxygen concentrator and ventilator. The ventilator can calculate a preset oxygen concentration based on an oxygen concentration input by the user. The ventilator can also calculate the preset oxygen concentration based on a measured ventilator ventilation output. The ventilator can also calculate the preset oxygen concentration based on a measured pressure at the ventilator's patient ventilation interface.

[0017] The ventilator may include: a flow sensor for measuring the flow rate of gas expelled from one or more nozzles connected to the patient ventilation interface of the ventilator; a pressure sensor for measuring the pressure in the patient ventilation interface; and a main controller configured to issue commands based on the measured flow rate and measured pressure. The main controller may be configured to issue commands based on a calculation of the total flow rate of gas delivered by the ventilator and entrained air, wherein the total flow rate of gas delivered by the ventilator and entrained air is a function of the measured flow rate and measured pressure. The main controller may be configured to issue commands based on a comparison of the measured pressure with multiple measurements of the total flow rate of gas delivered by the ventilator and entrained air, wherein the multiple measurements of the total flow rate of gas delivered by the ventilator and entrained air are stored corresponding to multiple measurements of the pressure in the patient ventilation interface for the measured flow rate. The main controller may be configured to issue commands based on a comparison of the measured pressure with multiple measurements of the inhaled oxygen fraction %FiO2, wherein the multiple measurements of the inhaled oxygen fraction %FiO2 are stored corresponding to multiple measurements of the pressure in the patient ventilation interface for the measured flow rate.

[0018] The control signals generated by the controller can operate the compressor to maintain the preset oxygen concentration in the product storage tank.

[0019] Another aspect of the embodiments of this disclosure is an oxygen concentrator comprising: one or more adsorption sieve beds operable to remove nitrogen from air to produce concentrated oxygen at their respective outlets; a product tank fluidly coupled to the respective outlets of the one or more adsorption sieve beds; a compressor operable to pressurize ambient air; one or more sieve bed flow paths from the compressor to the respective inlets of the one or more adsorption sieve beds; a bypass compressor operable to pressurize ambient air, the bypass compressor being different from the compressor described above; a bypass flow path from the bypass compressor to the product tank, bypassing the one or more adsorption sieve beds; and a controller operable to generate a control signal to control the bypass compressor to selectively allow pressurized ambient air from the bypass compressor to flow along the bypass flow path.

[0020] Another aspect of the embodiments of this disclosure is an oxygen concentrator comprising: one or more adsorption sieve beds operable to remove nitrogen from air to produce concentrated oxygen at their respective outlets; a product tank fluidly coupled to the respective outlets of the one or more adsorption sieve beds; a compressor operable to pressurize ambient air; one or more sieve bed flow paths from the compressor to the respective inlets of the one or more adsorption sieve beds; a bypass flow path from an external compressor fluid port to the product tank, bypassing the one or more adsorption sieve beds; and a controller operable to generate a control signal thereby controlling an external compressor fluidly coupled to an external compressor fluid port via an external compressor signal port, the control signal selectively allowing pressurized ambient air from the external compressor to flow along the bypass flow path.

[0021] Another aspect of the embodiments of this disclosure is a modular system comprising the aforementioned oxygen concentrator, 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 detachably attached to form a single unit.

[0022] Another aspect of embodiments of this disclosure is a method for controlling an oxygen concentrator to meet the patient's ventilation and supplemental oxygen needs at multiple activity levels. The method may include converting the oxygen concentrator to a first configuration, wherein a first portion of ambient air, equal to or greater than the portion without ambient air, is mixed with concentrated oxygen output from one or more screens of the oxygen concentrator, thereby producing a concentrator output at a first flow rate having a first oxygen concentration. The method may further include converting the oxygen concentrator to a second configuration, wherein a second portion of ambient air, greater than the first portion, is mixed with concentrated oxygen output from one or more screens, thereby producing a concentrator output at a second flow rate having a second oxygen concentration, wherein the second flow rate is greater than the first flow rate and the second oxygen concentration is less than the first oxygen concentration.

[0023] Another aspect of embodiments of this disclosure is a method for controlling an oxygen concentrator to meet the patient's ventilation and supplemental oxygen needs at multiple activity levels. The method may include converting the oxygen concentrator to a first configuration in which a first portion of concentrated oxygen gas (equal to or greater than unconcentrated oxygen gas) output from one or more screens of the oxygen concentrator is mixed with ambient air to produce a concentrator output at a first flow rate having a first oxygen concentration. The method may further include converting the oxygen concentrator to a second configuration in which a second portion of concentrated oxygen gas (greater than the first portion) output from one or more screens is mixed with ambient air to produce a concentrator output at a second flow rate having a second oxygen concentration, wherein the second flow rate is less than the first flow rate and the second oxygen concentration is greater than the first oxygen concentration.

[0024] Another aspect of the embodiments of this disclosure is a method for calculating the total flow rate of gas and entrained air delivered to a patient by a ventilator. The method may include: storing one or more constants associated with each of a plurality of nozzle geometries; measuring the flow rate of gas discharged from one or more nozzles connected to a patient ventilation interface of the ventilator, the one or more nozzles having a nozzle geometry corresponding to one of the plurality of nozzle geometries; measuring pressure in the patient ventilation interface; and calculating the total flow rate based on the measured flow rate, the measured pressure, and the stored one or more constants associated with the nozzle geometries of the one or more nozzles.

[0025] The method may also include transmitting a signal to the oxygen concentrator based on the calculated total flow rate.

[0026] The method may further include calculating the total inhaled tidal volume by integrating the calculated total flow rate with respect to time. The method may also include transmitting a signal to the oxygen concentrator based on the calculated total inhaled tidal volume.

[0027] The method may further include: calculating the inhaled tidal volume of gas discharged from one or more nozzles by integrating the measured flow rate with respect to time; calculating the inhaled tidal volume of entrained air by integrating the entrained flow rate with respect to time, the entrained flow rate being the difference between the calculated total flow rate and the measured flow rate; and calculating the patient's inhaled oxygen fraction (%FiO2) based on the inhaled tidal volume of gas discharged from one or more nozzles and the inhaled tidal volume of entrained air. The method may further include transmitting a signal to an oxygen concentrator based on the calculated %FiO2.

[0028] For each of the multiple nozzle geometries, one or more associated constants are stored in a memory located in the patient ventilation interface of the nozzle having that geometry. Calculating the total flow rate may include reading one or more constants stored in the patient ventilation interface connected to the ventilator.

[0029] Another aspect of the embodiments of this disclosure is a method for controlling an oxygen concentrator based on the total flow rate of gas delivered to a patient by a ventilator and the entrained air. The method may include: measuring the flow rate of gas discharged from one or more nozzles connected to a patient ventilation interface of the ventilator; measuring the pressure in the patient ventilation interface; calculating the total flow rate based on the measured flow rate and the measured pressure; and transmitting a signal to the oxygen concentrator based on the calculated total flow rate.

[0030] The method may also include calculating the total inhaled tidal volume by integrating the calculated total flow rate with respect to time. Signal transmission may be based on the calculated total inhaled tidal volume.

[0031] The method may further include: calculating the inhaled tidal volume of gas discharged from one or more nozzles by integrating the measured flow rate with respect to time; calculating the inhaled tidal volume of entrained air by integrating the entrained flow rate with respect to time, the entrained flow rate being the difference between the calculated total flow rate and the measured flow rate; and calculating the patient's inhaled oxygen fraction (%FiO2) based on the inhaled tidal volume of gas discharged from one or more nozzles and the inhaled tidal volume of entrained air. Signal transmission may be based on the calculated %FiO2.

[0032] Another aspect of embodiments of this disclosure is a non-transitory program storage medium storing instructions executable by a processor or programmable circuitry to perform operations for controlling an oxygen concentrator based on the total flow rate of gas delivered to the patient by a ventilator and the entrained air. This operation may include: measuring the flow rate of gas expelled from one or more nozzles connected to the patient ventilation interface of the ventilator; measuring the pressure in the patient ventilation interface; and calculating the total flow rate based on the measured flow rate and measured pressure.

[0033] Another aspect of the embodiments of this disclosure is a ventilator that includes the aforementioned non-transitory program storage medium, a processor or programmable circuit for executing instructions, a flow sensor, and a pressure sensor. Measuring flow may include communicating with the flow sensor, and measuring pressure may include communicating with the pressure sensor.

[0034] Another aspect of the embodiments of this disclosure is a ventilation system comprising the aforementioned ventilator and an oxygen concentrator connected to the ventilator. Operation may further include transmitting a signal from the ventilator to the oxygen concentrator based on a calculated total flow rate.

[0035] The oxygen concentrator may include a controller capable of generating control signals in response to signals transmitted from a ventilator. These control signals selectively allow pressurized ambient air to flow into the product reservoir of the oxygen concentrator. The control signals generated by the controller can operate valve units of the oxygen concentrator to maintain a preset oxygen concentration in the product reservoir according to signals transmitted from the ventilator. The control signals generated by the controller can also operate valve units to allow pressurized ambient air to flow around one or more screens of the oxygen concentrator. The control signals generated by the controller can operate the compressor of the oxygen concentrator to maintain a preset oxygen concentration in the product reservoir according to signals transmitted from the ventilator. Finally, the control signals generated by the controller can operate an external compressor of the oxygen concentrator to maintain a preset oxygen concentration in the product reservoir according to signals transmitted from the ventilator.

[0036] Another aspect of embodiments of this disclosure is a method for controlling an oxygen concentrator to meet the patient's ventilation and supplemental oxygen needs at multiple activity levels. The method may include converting the oxygen concentrator to a first configuration, wherein a first portion of ambient air is mixed with concentrated oxygen output from one or more screens of the oxygen concentrator to produce a concentrator output at a first flow rate having a first oxygen concentration. The method may further include converting the oxygen concentrator to a second configuration, wherein a second portion of ambient air is mixed with concentrated oxygen output from one or more screens to produce a concentrator output at a second flow rate having a second oxygen concentration, wherein the second flow rate is greater than the first flow rate and the second oxygen concentration is less than the first oxygen concentration.

[0037] Another aspect of embodiments of this disclosure is a method for estimating the total flow rate of gas and entrained air delivered to a patient by a ventilator. The method may include: storing, for each of a plurality of measurements of the flow rate of gas expelled from one or more nozzles connected to a patient ventilation interface of the ventilator, a plurality of measurements of the total flow rate corresponding to a plurality of measurements of pressure in the patient ventilation interface; measuring the flow rate of gas expelled from the one or more nozzles; measuring the pressure in the patient ventilation interface; and estimating the total flow rate based on a comparison of the measured pressure with the plurality of measurements of the total flow rate stored for the measured flow rate.

[0038] The method may also include transmitting a signal to the oxygen concentrator based on the estimated total flow rate.

[0039] The method may further include calculating the patient's inhaled oxygen fraction (%FiO2) based on the percentage of oxygen contained in the gas discharged from one or more nozzles and an estimated total flow rate. The method may also include transmitting a signal to an oxygen concentrator based on the calculated %FiO2.

[0040] Another aspect of embodiments of this disclosure is a method for estimating the fractional oxygen (%FiO2) of a patient receiving ventilatory support from a ventilator. The method may include: storing multiple measurements of %FiO2 corresponding to multiple measurements of pressure in the patient ventilation interface for each of multiple measurements of the flow rate of gas expelled from one or more nozzles connected to the ventilator; measuring the flow rate of gas expelled from the one or more nozzles; measuring the pressure in the patient ventilation interface; and estimating the patient's %FiO2 based on a comparison of the measured pressure with the multiple measurements of %FiO2 stored for the measured flow rate.

[0041] The method may also include transmitting a signal to the oxygen concentrator based on the estimated %FiO2. Attached Figure Description

[0042] These and other features and advantages of the various embodiments disclosed herein will be better understood with reference to the following description and accompanying drawings, wherein like reference numerals denote like parts throughout, and wherein:

[0043] Figure 1 An exemplary oxygen concentrator according to an embodiment of the present disclosure is shown;

[0044] Figure 2 Exemplary control signals for controlling a valve unit of an oxygen concentrator are shown in the case of a bypass flow path including an on / off valve;

[0045] Figure 3 An exemplary control signal for controlling a valve unit in the case of a bypass flow path including a proportional valve is shown.

[0046] Figure 4 An example of an oxygen concentrator is shown for use with a dedicated bypass compressor, which is a separate add-on component;

[0047] Figure 5 An exemplary modular system including an oxygen concentrator module and a compressor module is shown;

[0048] Figure 6 Another exemplary modular system including an oxygen concentrator module is shown;

[0049] Figure 7 An exemplary ventilation system according to an embodiment of the present disclosure is shown;

[0050] Figure 8 An exemplary operating procedure that can be performed entirely or partially by a ventilator is shown;

[0051] Figure 9 Examples of nozzle stagnation pressures calculated and measured at different flow rates are shown;

[0052] Figure 10 The nozzle characteristics P, calculated and measured at different flow rates, are shown. aw -Q T Example of a curve;

[0053] Figure 11 Another exemplary operating procedure that can be performed entirely or partially by a ventilator is shown; and

[0054] Figure 12 Another exemplary operating procedure that can be performed entirely or partially by a ventilator is shown. Detailed Implementation

[0055] This disclosure includes various embodiments of oxygen concentrators, ventilators, and control systems and methods thereof. The detailed description set forth below with reference to the accompanying drawings is intended as a description of several currently contemplated embodiments and is not intended to represent the only form in which the disclosed invention can be developed or utilized. The description illustrates functions and features in conjunction with the illustrated embodiments. However, it should be understood that the same or equivalent functions can be implemented by different embodiments, and these different embodiments are also intended to be included within the scope of this disclosure. It should also be understood that the use of relational terms such as "first" and "second" is only for distinguishing one entity from another and does not necessarily require or imply any actual such relationship or order between these entities.

[0056] Figure 1An exemplary oxygen concentrator 100 according to an embodiment of the present disclosure is shown. As shown, a ventilator 200 is arranged to deliver a gas with a high oxygen content produced by the oxygen concentrator 100 to a patient 13 via a patient ventilation interface 12. Depending on various factors, including, for example, the patient 13's medication prescription, the patient's activity level, user-adjustable settings, and the patient's respiratory status at a given moment, the ventilator 200 may instruct the oxygen concentrator 100 to produce a gas with a specific flow rate (e.g., volumetric flow rate) having a specific oxygen concentration. The ventilator 200 can then provide such a high oxygen content gas to the patient 13 via the patient ventilation interface 12, taking into account any entrainment of additional ambient air in the patient ventilation interface 12, to provide the patient 13 with the required level of patient breathing work assistance and target FiO2.

[0057] Typically, to generate a gas with a high oxygen content from ambient air, the compressor 110 of the oxygen concentrator 100 pumps ambient air through one or more adsorption sieve beds 120, which remove nitrogen from the pressurized air. The resulting gas, with a high oxygen concentration (e.g., >90%), flows into a product tank 130 for delivery to a ventilator 200. More specifically, the controller 140 of the oxygen concentrator 100 can control a valve unit 150 to periodically allow pressurized ambient air to enter the sieve beds 120 and discharge nitrogen waste extracted by the sieve beds. Figure 1 As shown, for example, two screen beds 120 (e.g., screen bed A and screen bed B) with opposite operating cycles can be provided, where screen bed A fills the product storage tank 130 with a gas containing a high oxygen content while screen bed B is releasing nitrogen into the environment, and vice versa.

[0058] This disclosure envisions various ways to modify and / or supplement such a process in order to fine-tune the oxygen concentrator 100 to produce a desired gas flow rate at a specific oxygen concentration. Such an oxygen concentrator 100 can be used with a ventilator 200 to meet the changing needs of the patient 13 in real time.

[0059] Referring more closely to the arrangement of valves and conduits in valve unit 150, it can be seen that... Figure 1An exemplary oxygen concentrator 100 provides a first screen bed flow path 160a and a second screen bed flow path 160b. The first screen bed flow path 160a extends from the compressor 110 through valve V1 of valve unit 150 to the inlet of screen bed A, and the second screen bed flow path 160b extends from the compressor 110 through valve V3 of valve unit 150 to the inlet of screen bed B. In addition to these screen bed flow paths 160a and 160b, the oxygen concentrator 100 also includes a bypass flow path 170, which bypasses one or more screen beds 120 and extends from the compressor 110 through valve V6 of valve unit 150 to product tank 130. By controlling valve V6, controller 140 can allow pressurized ambient air from compressor 110 to flow directly to product tank 130 without first passing through screen bed 120. This ambient air, avoiding the pressure drop associated with screen bed 120, can then be mixed in product tank 130 with the high-oxygen-content gas output from screen bed 120. Compared to filling the product tank 130 solely from the sieve bed 120, the mixture of ambient air and sieve bed output can accumulate more rapidly in the product tank 130 with a lower oxygen concentration due to the additional volume of ambient air flowing through the bypass flow path 170. By appropriately controlling the valve unit 150, the controller 140 can selectively control the flow rate into the product tank 130 and the oxygen concentration of the resulting product gas to meet the needs of the ventilator 200.

[0060] For example, to achieve an oxygen concentration of 93%, a compressor in a conventional oxygen concentrator without a bypass flow path 170 might need to produce approximately 10 times the required flow rate at the concentrator's output. That is, a 2 L / min oxygen concentrator might need to produce 20 L / min of compressed gas to generate 2 L / min of oxygen. By using the bypass flow path 170, the oxygen concentrator 100 of this disclosure allows for a trade-off between the delivered oxygen concentration and the continuous flow rate (e.g., minute ventilation) that the oxygen concentrator 100 can deliver. For example, instead of delivering a flow rate of 2 L / min, the oxygen concentrator 100 could be configured to deliver 3.8 L / min of oxygen (via the screen bed 120) and 2 L / min of ambient air (via the bypass valve 170). The oxygen concentration of the delivered gas would decrease to approximately 60%, but the total flow rate would increase to 3.8 L / min. Downstream ventilator 200 amplifies this flow rate with entrained air at a ratio of approximately 3:1, so by using ventilator 200, oxygen concentrator 100 can deliver a minute ventilation of 11.4 L / min (3*3.8) with approximately 32% FiO2. In contrast, when delivering 2 L / min of 93% oxygen, oxygen concentrator 100 amplified by ventilator 200 will only deliver 6 L / min (3*2) to patient 13, but with 50% FiO2. Thus, oxygen concentrator 100 can produce up to 20 L / min of air (completely bypassing screen bed 120), which can then be amplified by ventilator 200 to 60 L / min (20*3) with approximately 21% (oxygen concentration in ambient air) FiO2. This allows the small oxygen concentrator 100 to meet the minute level requirements of a very active patient 13. As the patient's activity level increases, it is better to provide more ventilation and less oxygen, rather than more oxygen. By using the bypass flow path 170, the oxygen concentrator 100 can vary the total gas output between, for example, 2 L / min and 20 L / min, with the oxygen concentration correspondingly varying from approximately 93% to approximately 21%. The oxygen concentrator 100 can thus function simultaneously as a compressor and an oxygen concentrator, and its titration level can be controlled by the ventilator 200, as described below.

[0061] Controller 140 can control valve unit 150 by generating control signals for the individual valves (e.g., V1-V6) of valve unit 150. For example, control signals can be generated in response to commands issued by ventilator 200. In this case, valve unit 150 can be controlled according to a master / slave arrangement, where ventilator 200 acts as the master and controller 140 or oxygen concentrator 100 acts as the slave. Ventilator 200 (e.g., based on inputs such as patient 13's prescription, patient activity level, user-adjustable settings, and the patient's respiratory status measured by ventilator 200) can derive setpoints for flow rate and / or oxygen concentration, and controller 140 can appropriately generate control signals to achieve these setpoints. When generating control signals, controller 140 can also consider measurements from pressure sensor 180 and / or oxygen concentration sensor 190, which are fluidly coupled to the outlet of product reservoir 130. These measurements can be fed back to controller 140 and can be used as additional inputs along with the setpoints from ventilator 200. The controller 140 can be used, for example, as a proportional-integral-derivative (PID) controller or to perform other known control loop feedback mechanisms.

[0062] Figure 2 An exemplary control signal for controlling valve unit 150 is shown when bypass flow path 170 includes on / off valve V6. Figure 2 In the example, valve unit 150 is controlled to perform a three-stage cycle, wherein compressed air from compressor 110 passes through screen bed A in the first stage, through screen bed B in the second stage, and directly into product tank 130 via on / off valve V6 and bypass flow path 170 in the third stage.

[0063] Figure 3 An exemplary control signal for controlling valve unit 150 is shown when the bypass flow path 170 includes a proportional valve V6. Figure 3 In the example, the control valve unit 150 performs a two-stage cycle, in which compressed air from the compressor 110 passes through the screen bed A in the first stage and through the screen bed B in the second stage, and the proportional valve V6 is always in a controlled state to selectively allow a portion of the compressed air to enter the product storage tank 130 directly via the bypass flow path 170.

[0064] In relation to Figures 1 to 3In the example described, the bypass flow path 170 directly connects the product tank 130 to the compressor 110, i.e., fluidly connected to the same compressor 110 as the screen bed 120. The disclosed subject matter is not intended to be limited thereto. For example, the bypass flow path 170 may alternatively extend from a separate dedicated bypass compressor, distinct from the compressor 110. This dedicated bypass compressor can be turned on and off, or its output (e.g., revolutions per minute (rpm)) can be adjusted according to control signals generated by the controller 140, to selectively allow flow from the dedicated bypass compressor to the product tank 150, achieving the same effect as valve V6 of valve unit 150. In cases where the dedicated bypass compressor is controlled in this manner, valve V6 can be omitted. The dedicated bypass compressor may be included within the housing of the oxygen concentrator 100, or it may be a separate add-on whose output is connected to the bypass flow path 170 of the oxygen concentrator 100 via a dedicated connector.

[0065] Figure 4 An example of an oxygen concentrator 400 for use with a dedicated bypass compressor, which is a separate add-on component as described above. The oxygen concentrator 400 can be used with... Figure 1 The oxygen concentrator 100 described is identical and may include a compressor 410, a sieve bed 420, a product storage tank 430, a controller 440, a valve unit 450, sieve bed flow paths 460a, 460b, a bypass flow path 470, a pressure sensor 480, and an oxygen concentration sensor 490, which are identical to the compressor 110, sieve bed 120, product storage tank 130, controller 140, valve unit 150, sieve bed flow paths 160a, 160b, bypass flow path 170, pressure sensor 180, and oxygen concentration sensor 190 of the oxygen concentrator 100, but have the following differences. Figure 1 The bypass flow path 170 extends from the compressor 110 to the product storage tank 130, but Figure 4 The bypass flow path 470 does not extend from the compressor 410 to the product tank 430, but instead extends from the external compressor fluid port 472 to the product tank 430. Furthermore, valve V6 of valve unit 150 is omitted in valve unit 450, and the control signal generated by controller 440 is used to control the external bypass compressor via external compressor signal port 474. As described above, this external bypass compressor can be opened and closed or the output of the external compressor can be adjusted according to the control signal to achieve the same effect as valve V6.

[0066] Figure 5 An exemplary modular system 500 is shown, including an oxygen concentrator module 510 and a compressor module 520. The oxygen concentrator module 510 can accommodate... Figure 4The system comprises an oxygen concentrator 400 (e.g., providing 0-2 liters of O2 per minute or 0-20 liters of air per minute at 20-30 PSI and having a 100Wh battery with a 1-2 hour range), and a compressor module 520 housing an external compressor (e.g., providing 0-10 liters of air per minute at 20-30 PSI and having a 100Wh battery with a 2-3 hour range). As indicated by the large arrows at the top and bottom of the modular system 500, the oxygen concentrator module 510 and compressor module 520 can be detachably attached to form a single unit. For example, a user can slide the two modules 510, 520 together along the direction of the arrows to lock them together as a single unit, with the external compressor fluid port 472 of the oxygen concentrator module 510 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 electrically connected to the signal input port of the compressor module 520. Sliding the two modules 510 and 520 in opposite directions unlocks and separates them, allowing them to be used separately. Thus, the oxygen concentrator module 510 can be used by patients requiring only oxygen therapy, the compressor module 520 by patients requiring only mechanical ventilation, and the combination of the two units can be used by people requiring both oxygen and mechanical ventilation. It is also conceivable that the top of the oxygen concentrator module 510 or the top of the compressor module 520 (or the combined surface formed by the tops of the oxygen concentrator module 510 and the compressor module 520) can be used as a bracket for placing the ventilator 200. Similarly, the bottom of the oxygen concentrator module 510 or the bottom of the compressor module 520 (or the combined surface formed by the bottoms of the oxygen concentrator module 510 and the compressor module 520) can be used as an attachment for an auxiliary battery pack.

[0067] Figure 6 Another exemplary modular system 600 including an oxygen concentrator module 610 is shown. The oxygen concentrator module 610 can accommodate... Figure 1 Oxygen concentrator 100 or Figure 4The oxygen concentrator module 400. As shown, the modular system 600 has additional modularity in the option of attaching an auxiliary hot-swappable battery pack 620 and / or a continuous positive airway pressure (CPAP) module 630 (e.g., using a 22mm ISO tapered connector for CPAP) to the oxygen concentrator module 610. The top of the oxygen concentrator 610 can serve as a bracket for attaching the CPAP module 630 and can include a latch release and electrical contacts. Similarly, the bottom of the oxygen concentrator 610 can serve as a bracket for attaching the battery pack 620 and can include a latch release and electrical contacts. The oxygen concentrator module 610 may also include a Diameter Index Safety System (DISS) or Quick Connect and a user interface that includes, for example, an on / off button, a battery level indicator, and wireless ventilator connectivity for the ventilator 200. This modularity can be replaced or added to, as per the above description. Figure 5 The modular system 500 describes the attachment of the external compressor module 520.

[0068] In the above examples of oxygen concentrators 100, 400, 510, 610, selective control of the flow rate into the product tanks 130, 430 and the oxygen concentration of the resulting product gas is achieved by bypassing the sieve beds 120, 420 of the oxygen concentrators 100, 400, 510, 610 via bypass flow paths 170, 470. However, this disclosure is not intended to be limited thereto. For example, controllers 140, 440 may intentionally “confuse” the timing of valves in oxygen concentrators conventionally constructed in other ways. Typically, the timing of valves in an oxygen concentrator is set to produce the most efficient oxygen extraction in the sieve beds. By controlling compressors 110, 410 and / or valve units 150, 450 to modify the timing of sieve bed circulation, controllers 140, 440 may intentionally prevent oxygen and nitrogen from having sufficient time to completely separate in the sieve beds 120, 420. As a result, product reservoirs 130, 430 can be filled with product gas having a reduced oxygen concentration, and can potentially allow the product gas to flow downstream to ventilator 200 at a higher flow rate. Controllers 140, 440 can, for example, refer to a lookup table of suboptimal compressor output and valve control timing that does not achieve the most efficient oxygen and nitrogen separation in screen beds 120, 420. Using such a lookup table, controllers 140, 440 can generate control signals in response to commands from ventilator 200 to meet the changing needs of patient 13 in real time. In this case, bypass flow paths 170, 470 and valve V6 can be omitted.

[0069] Figure 7 An exemplary ventilation system 700 according to an embodiment of the present disclosure is shown. As shown, the ventilation system 700 may include, for example: Figure 1 and Figure 4 The ventilator 200 and the patient ventilation interface 12, which is placed in fluid communication with the patient 13, are shown, as well as respectively regarding Figure 1 , Figure 4 , Figure 5 and Figure 6 Any of the oxygen concentrators 100, 400, 510, and 610 described herein. The ventilator 200 may be arranged to deliver high-oxygen-content gas produced by the oxygen concentrators 100, 400, 510, and 610 to the patient 13 via a patient ventilation interface 12. The patient ventilation interface 12 may include a device such as a full-face mask or nasal mask, which may be positioned to have direct airflow communication with the upper respiratory tract (i.e., the nasal cavity and / or oral cavity) of the patient 13. In addition to one or more nozzles 15 for delivering high-oxygen-content gas to the patient 13, the patient ventilation interface 12 may also have one or more openings for entraining additional ambient air for delivery to the patient 13. Examples of patient ventilation interfaces 12 with nozzle 15 and entrainment orifices that can be used in the subject matter of this disclosure can be found, for example, in U.S. Patent Application Publication No. 2019 / 0099570 entitled “Patient Interface with Integrated Jet Pump,” the entire disclosure of which is incorporated herein by reference, and examples of such patient ventilation interfaces 12 may include, for example, those from Breathe Technologies, Inc. The ventilation system includes Engage, Inspire, and Universal Circuit. TM The Connector (UCC) is a patient interface. This allows the total flow rate (e.g., volumetric flow rate) Q of the gas and entrained air delivered to the patient 13 by the ventilator 200 to be monitored at any given time. T Defined as the sum of the following: the nozzle flow rate Q of the gas discharged from one or more nozzles 15 of the patient ventilation interface 12. N and the entrainment flow rate Q of ambient air entrained by one or more nozzles 15 E That is, the total flow Q T It can be defined as Q T =Q N +Q E .exist In the case of a ventilation system, the flow rate Q N It can be 5-40 L / min, for example, it can be maintained for a duration of up to 3.0 seconds.

[0070] The entrained flow rate Q depends on various factors, including, for example, the patient's prescription, the patient's activity level, user-adjustable settings, and the patient's respiratory status at a given moment. E (and therefore the total flow Q) TThe percentage of oxygen (FiO2) inhaled by the patient may vary, resulting in a proportional variation in the amount of oxygen delivered with or without more or less ambient air as one or more nozzles 15 discharge gas with a high oxygen content. This is achieved by measuring the flow rate Q of the gas discharged from one or more nozzles 15. N In addition to the pressure in the patient ventilation interface 12, the ventilator 200 can calculate or estimate the total flow rate Q. T The ventilator 200 can instruct the oxygen concentrators 100, 400, 510, and 610 to adjust according to the estimated or calculated total flow rate Q. T This generates a specific flow rate of gas with a specific oxygen concentration. The ventilator 200 can then deliver this high-oxygen-content gas to the patient 13 via the patient ventilation port 12, thereby providing the patient 13 with the required level of patient breathing work assistance and target %FiO2, taking into account the additional ambient air entrained in the patient ventilation port 12.

[0071] The ventilator 200 may include a first inlet port 16 through which oxygen concentrators 100, 400, 510, and 610 supply high-oxygen-content gas. The first inlet port 16 may communicate with an inlet filter 24, which removes particulate matter and other contaminants from the breathing gas ultimately delivered to the patient. The pressure of the high-oxygen-content gas originating from the oxygen concentrators 100, 400, 510, and 610 may be regulated by a valve 26 having a valve inlet port 26a in airflow communication with the inlet filter 24 and a valve outlet port 26b in airflow communication with the outlet port 28 of the ventilator 200. The state of valve 26 may be selectively adjusted to deliver a desired volume / pressure of gas from the oxygen concentrators 100, 400, 510, and 610 to the patient 13. Actuation of valve 26 may be controlled by a controller 30, which performs various methods contemplated in this disclosure, as will be described in further detail below.

[0072] The respiratory gas flow delivered through valve 26 can enter the gas delivery conduit 32 connected to the patient ventilation interface 12 via outlet port 28. Gas delivery conduit 32 can be, for example, a plastic tube with a predetermined inner diameter (such as 22 mm or less). Depending on the respiratory status of the patient 13, a pressure difference may occur between the patient ventilation interface 12 and the output of valve 26 (i.e., valve outlet port 26b).

[0073] To determine this pressure difference, the ventilation system 700 may include dual pressure sensors, namely a valve pressure sensor 34 and a patient interface pressure sensor 36. The valve pressure sensor 34 may be located within the ventilator 200 and can monitor the pressure at the valve outlet port 26b. The patient interface pressure sensor 36 may also be physically located within the ventilator 200, but in direct airflow communication with the patient ventilation interface 12 via a pressure sensor line 38 connected to the sensor inlet port 40 of the ventilator 200. During operation of the ventilator 200, the pressure sensor line 38 can be purged by connecting the pressure sensor line 38 and the gas line 32 to deliver a purge flow. This can be accomplished via a purge solenoid 42 connected to both. Depending on the patient's respiratory stage or the pressure difference between the valve pressure and the patient interface pressure, the purge may be continuous or intermittent.

[0074] In addition to measuring the pressure difference between the patient ventilation port 12 and the valve output 26b, the flow rate of the actual respiratory gas output from valve 26 can also be utilized. For this purpose, the ventilator 200 may include a flow sensor 43 aligned with valve 26 and outlet port 28.

[0075] The ventilator 200 can measure the pressure in the patient ventilation interface 12 and the flow rate of gas expelled from 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 pressure, and can communicate with the flow sensor 43 to measure flow rate. Based on the measured pressure and flow rate, the controller 30 can then estimate or calculate the total flow rate Q. T And / or various other parameters, as described in more detail below. For this purpose, the ventilator 200 may also include a nozzle data memory 31, which can store one or more constants associated with each of the plurality of nozzle geometries. During use, the controller 30 can calculate the total flow rate Q based on the measured flow rate, the measured pressure, and the stored one or more constants associated with the nozzle geometries of one or more nozzles 15. T Based on the calculated total flow Q T The controller 30 can also calculate the patient's %FiO2. The controller 30 can continuously calculate the total flow rate Q in real time, based on changes in the user's activity level and breathing, and as user-adjustable settings of the ventilator 200 are modified (e.g., using inputs 69 such as a touchscreen or buttons and outputs 62 such as a display). T And / or 13% FiO2 in patients.

[0076] Based on the calculated total flow Q TAnd / or the patient's %FiO2, controller 30 can instruct oxygen concentrators 100, 400, 510, 610, for example, by transmitting a signal (e.g., a radio frequency wireless signal) from ventilator 200 to oxygen concentrators 100, 400, 510, 610. Upon receiving the signal from ventilator 200, oxygen concentrators 100, 400, 510, 610 can adjust the pressure, flow rate, and / or oxygen concentration of the high-oxygen-content gas they produce to meet the patient's changing needs in real time. This can be achieved as described above regarding... Figure 1 and Figure 4 This adjustment is performed within the oxygen concentrators 100, 400, 510, and 610 as described. Thus, the ventilator 200 can control the oxygen concentrators 100, 400, 510, and 610 according to a master / slave arrangement, where the ventilator 200 acts as the master and the oxygen concentrators 100, 400, 510, and 610 act as slaves.

[0077] Figure 8 An exemplary operating procedure, which can be performed in whole or in part by a ventilator 200, is shown according to an embodiment of the disclosed subject matter. Figure 8 The operating procedure can be used to measure the flow rate Q of the gas discharged from one or more nozzles 15. N (Nozzle flow rate) and the measured pressure P in patient ventilation port 12 aw Calculate the total flow rate Q using airway pressure. T Equivalently, given the known flow rate Q of the gas discharged from one or more nozzles 15... N In this case, Figure 8 The operating procedure can be used to calculate the flow rate Q through nozzle 15. N The entrained flow Q E =Q T -Q N And various other values ​​derived from this.

[0078] Typically, entrainment is affected by the pressure downstream of the nozzle at the patient ventilation port 12 (e.g., In the case of nozzle 15 at the patient ventilation interface of the system, this pressure can be regarded as the measured pressure P. aw When pressure P aw Reaching stagnation pressure P S At that time, due to the back pressure in the patient's airway and lungs, the flow rate Q through nozzle 15... N Equal to 0. Stagnation pressure P S It can be used to calculate Q according to the following formula. N and P aw The total flow of the function Q T :

[0079]

[0080] Among them, the stagnation pressure P S It is the flow rate Q of the discharged gas. N The function can be calculated as a quadratic equation.

[0081]

[0082] a, b, and c are constants that depend on the specific nozzle geometry. The constants a, b, and c can be predetermined for each nozzle geometry by finding the stagnation pressure that a given flow rate will produce. In the case of the system's UCC patient interface, a = 0.0191, b = 0.3828, thus yielding Figure 9 The pressure P shown is for stagnant pressure. aw With nozzle flow rate Q N The calculation relationship between them, i.e., the stagnant pressure P S Nozzle flow rate Q N function or P S (Q N For the UCC patient interface, c=8, resulting in... Figure 10 The diagram shows the flow rates Q for multiple nozzles. N The total flow rate Q for each of the following (5, 10, 20, 30, and 40 L / min) T and pressure P aw The calculation relationship between them.

[0083] Figure 8 The operation flow can begin at step 802, where one or more constants associated with each of the multiple nozzle geometries are stored. For example, this can be for (e.g., for...) Each of the multiple nozzle geometries in the system's Engage, Inspire, and UCC patient interfaces stores the aforementioned constants a, b, and c. These constants can be stored in, for example... Figure 7 The nozzle data is stored in the nozzle data memory 31 shown. Alternatively, these constants can be stored in the patient ventilation interface 12 itself, for example, in a memory (e.g., an electrically erasable programmable read-only memory (EEPROM)) stored in its wiring harness, so that each patient ventilation interface 12 can store constants a, b, and c associated with its own specific nozzle geometry. This can allow individual nozzles to be calibrated separately from the ventilator 200 to address manufacturing differences between nozzles.

[0084] During the treatment of patient 13 using ventilation system 700 Figure 8 The operation can continue to steps 804 and 806, in which step 804, the flow rate Q of the gas discharged from one or more nozzles 15 of the patient ventilation interface 12 is measured. NIn step 806, the pressure P in the patient ventilation port 12 is measured. aw Measure pressure P aw This may include communication between the controller 30 and the valve pressure sensor 34 and the patient interface pressure sensor 36. For example, measuring pressure P aw This can be defined as the difference between the pressure in the patient ventilation port 12 measured by the patient interface pressure sensor 36 and the pressure at the valve outlet port 26b measured by the valve pressure sensor 34. After acquiring the measured flow rate Q... N and measuring pressure P aw In this case, the operation procedure can continue to step 808, in which the total flow rate Q of the gas and entrained air delivered by the ventilator 200 to the patient 13 is calculated. T For example, controller 30 can use the above equation based on the measured flow rate Q. N and measuring pressure P aw And the stored constants a, b, and c are used to calculate the total flow Q. T For example, by using constants a and b and measuring flow rate Q N To calculate the stagnation pressure P S Then use the flow rate Q N Measure pressure P aw Stagnation pressure P S The total flow rate Q is calculated using the constant c. T In calculating the total flow Q T When the constants are stored in the nozzle data memory 31, the controller 30 can read the constants a, b and c from the external memory, or when the constants are stored in the memory of the patient ventilation interface 12, the controller 30 can read the constants a, b and c from the external memory when the patient ventilation interface 12 is connected to the ventilator 200 (e.g., via a smart connector that downloads the constants to the ventilator 200).

[0085] In step 810, the total flow rate Q can be calculated. T Any of the various values ​​derived therefrom, such as one or more inhaled tidal volumes. For example, total inhaled tidal volume (TotV). t It can be calculated as the total flow rate Q. T The tidal volume NozV of the gas discharged from one or more nozzles 15, as an integral over time. t It can be calculated as the measured flow rate Q N The integral over time, and / or the amount of inhaled tidal air entrained (EntV) t It can be calculated as entrained flow rate Q E =Q T -Q NIntegral over time. In step 812, the controller 30 may calculate %FiO2 based on the inhaled tidal volume of the gas discharged from one or more nozzles 15 and the inhaled tidal volume of entrained air. For example, assuming the gas discharged from one or more nozzles 15 is 100% oxygen, then %FiO2 can be calculated as %FiO2 = 100 (NozV) t +0.21EntV t ) / TotV t 21% is approximately the percentage of oxygen in ambient air. More generally, for any gas discharged from one or more nozzles 15 (e.g., as described above, where oxygen concentrators 100, 400, 510, 610 are controlled to deliver a lower oxygen concentration), %FiO2 can be calculated as: %FiO2 = 100 (NozV) t +0.21EntV t ) / TotV t 100X is the percentage of oxygen contained in the gas discharged from one or more nozzles 15. The value X can be determined based on the known oxygen concentration of the gas supplied by the oxygen concentrators 100, 400, 510, 610 (e.g., based on the current / previous setpoint issued by the controller 30 and / or the measurement value of the oxygen concentration sensor 190), and the value X defines the oxygen concentration of the gas discharged from one or more nozzles 15.

[0086] Finally, in step 814, the controller 30 of the ventilator 200 can, based on the calculated total flow rate Q, T Or %FiO2, for example, as described above, by transmitting a signal from the ventilator 200 to the oxygen concentrators 100, 400, 510, 610 to instruct them. 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-content gas they produce to generate a desired total flow rate Q. T And / or %FiO2.

[0087] In the example above, constants a, b, and c are stored for each nozzle geometry. However, it is also conceivable that only the constant c can be stored for each nozzle geometry, for the possible flow rates Q. N Further storage of stagnant pressure P S If the ventilator 200 is designed for a single nozzle geometry, it may not be necessary to store any constants at all, and step 802 can be omitted. Total flow rate Q T It can be simply used as a measure of flow rate Q N and measuring pressure P awThe function is calculated without modifying the above equations for different nozzle geometries.

[0088] Figure 9 An example of nozzle stagnation pressure calculated and measured at different flow rates is shown. As mentioned above, constants a = 0.191 and b = 0.3828 and the stagnation pressure P are used. S The above equation is used to generate Figure 9 The calculation relationships are shown. Figure 9 Another relationship shown (“measured cmH2O”) is the stagnation pressure P measured at the UCC patient interface. S The experimental results. From Figure 9 As can be seen, the measured relationship matches the calculated relationship very well, indicating that the stagnant pressure P S and nozzle flow rate Q N There is a secondary relationship between them.

[0089] Figure 10 The calculation and measurement of P for nozzles at different flow rates are shown. aw -Q T An example of a curve. As mentioned above, Figure 10 The calculation relationship shown uses the constant c = 8 and the total flow rate Q mentioned above. T The equation is generated, where the total flow Q is... T It is for different nozzle flow rates Q N airway pressure P aw The function. Other relations ("Act-5", "Act-10", etc.) are for nozzle flow rates Q of 5, 10, 20, and 40 L / min. N Measure total flow Q T airway pressure P aw The actual experimental results regarding the relationship between them. For example... Figure 10 As shown, the measured relationship matches the calculated relationship very well, indicating that the airway pressure P aw With total flow Q T There is a linear relationship between them.

[0090] Figure 11 Another exemplary operating procedure, which can be performed in whole or in part by a ventilator 200, is shown according to an embodiment of the disclosed subject matter. Figure 11 In the example, constants a, b, and c, along with the total flow Q, are not used as described above. T and stagnation pressure P S The relationship between the total flow Q and the total flow Q is used to calculate the total flow. T Instead, it can specify the predetermined characteristics P for a given nozzle (or multiple nozzles). aw -Q T The curve is pre-stored and used to estimate the pressure P being measured. awand nozzle flow rate Q N Total flow Q T The operation can begin at step 1102, where the total flow rate data is stored, for example, in the nozzle data memory 31 of the ventilator 200. For instance, the total flow rate data may include data for one or more nozzles. Figure 10 The characteristic curves (e.g., their underlying data, which may be stored in tabular form or as parameterized equations). Pre-stored characteristic curves, such as those with storage constants a, b, c, can alternatively be stored in the memory of each patient interface 12, characterizing that particular patient interface 12. For a given patient interface 12, the nozzle data memory 31 or external memory can be used for the flow rate Q of the gas discharged from one or more nozzles 15 of the patient ventilation interface 12. N Each of the multiple measurements (e.g., such as) Figure 10 Q shown N =5, 10, 20, 30, 40) to store the pressure P in the patient ventilation interface 12. aw The total flow rate Q corresponding to multiple measurements T Multiple measurements.

[0091] During the treatment of patient 13 using ventilation system 700 Figure 11 The procedure can continue to steps 1104 and 1106, in which step 1104, the flow rate Q of the gas discharged from one or more nozzles 15 of the patient ventilation interface 12 is measured. N In step 1106, as described above, the pressure P in the patient ventilation port 12 is measured. aw After obtaining the measured flow rate Q N and measuring pressure P aw In this case, the operation process can continue to step 1108, in which the measured pressure P is used as the basis for the operation. aw With regard to the measured flow rate Q N Total storage traffic Q T The total flow rate Q is estimated by comparing multiple measurements. T For example, controller 30 can refer to nozzle data memory 31 to query... Figure 10 The characteristic P shown aw -Q T Curve, find the flow rate Q N Corresponding characteristic P aw -Q T The curve is used to read and measure the pressure P along the curve. aw The corresponding total flow Q T The value of .

[0092] The total flow Q was estimated as described above.T In this case, Figure 11 The operation can continue to steps 1110, 1112, and 1114. In step 1110, one or more inhaled tidal volumes are calculated or calculated from the total flow rate Q. T Any of the various other values ​​obtained, in step 1112, the %FiO2 of patient 13 is calculated, and in step 1114, a signal is transmitted to oxygen concentrator 100; all these steps can be connected with... Figure 8 The operation process steps 810, 812, and 814 are performed in the same way. The only difference is that... Figure 10 In the case of total flow Q T It is estimated using pre-stored characteristic curves, rather than using measured pressure P. aw Measuring flow rate Q N It is calculated using one or more constants characterizing the patient interface 12. Upon receiving a signal from the ventilator 200, the oxygen concentrators 100, 400, 510, and 610 can adjust the pressure, flow rate, and / or oxygen concentration of the high-oxygen-content gas they produce to generate the desired total flow rate Q. T And / or %FiO2.

[0093] Figure 12 Another exemplary operating procedure, which can be performed in whole or in part by a ventilator 200, is shown according to an embodiment of the disclosed subject matter. Figure 12 In the example, it is not an estimation of the total flow Q. T Instead of using the patient's %FiO2 as a prerequisite for calculation, the %FiO2 data for each nozzle can be pre-stored and used to estimate the %FiO2 for the measured pressure P. aw and nozzle flow rate Q N The %FiO2. The operation can begin at step 1202, where the %FiO2 data is stored in, for example, the nozzle data memory 31 of the ventilator 200. The %FiO2 data may include characteristic curves (e.g., their baseline data, which may be stored in tabular form or as parametric equations) for one or more nozzles. Pre-stored characteristic curves, such as those storing constants a, b, c, may alternatively be stored in the memory of each patient interface 12, characterizing that particular patient interface 12. For a given patient interface 12, the nozzle data memory 31 or external memory may be used for the flow rate Q of the gas expelled from one or more nozzles 15 of the patient ventilation interface 12. N Multiple measurements (e.g., such as) Figure 10 As shown, Q N =5, 10, 20, 30, 40) to store the pressure P in the patient ventilation interface 12. awMultiple measurements correspond to multiple %FiO2 measurements. This characteristic P aw -% FiO2 curves can be obtained in the laboratory under various pressures P aw and nozzle flow rate Q N The %FiO2 measurement was obtained experimentally, or can be found in the above text. Figure 11 The operation process describes the export of total traffic data.

[0094] During the treatment of patient 13 using ventilation system 700 Figure 11 The operation can continue to steps 1204 and 1206. In step 1204, the flow rate Q of the gas discharged from one or more nozzles 15 of the patient ventilation interface 12 is measured. N In step 1206, the pressure P in the patient ventilation port 12 is measured as described above. aw After obtaining the measured flow rate Q N and measuring pressure P aw In this case, the operation process can continue to step 1208, in which the measured pressure P is... aw With regard to the measured flow rate Q N The patient's FiO2 is estimated by comparing multiple stored FiO2 measurements. For example, the controller 30 can refer to the nozzle data memory 31 to query %FiO2 data for a specific nozzle 15 and find the result relative to the measured flow rate Q. N Corresponding characteristic P aw -%FiO2 curve, and read and measure pressure P along this curve. aw The corresponding %FiO2 value. Given the patient's %FiO2 estimated as described above, Figure 12 The operation can continue to step 1210, in which a signal is transmitted to the oxygen concentrator 100. This step can be coordinated with... Figure 8 Step 814 or Figure 11 Step 1114 is performed in the same way. The only difference is that... Figure 12 In this case, %FiO2 is estimated directly using pre-stored characteristic curves, rather than based on the total flow Q. T Calculated. Upon 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 content gas they produce to achieve the desired entrainment rate and / or %FiO2.

[0095] exist Figure 8 , Figure 11 and Figure 12 In the above exemplary operation process, the total flow Q is calculated or estimated. TAnd / or the patient's %FiO2, which is used to characterize the patient's needs at a given moment to control the oxygen concentrator 100. However, the subject matter disclosed is not intended to be limited to these specific parameters. For example, various derived or other relevant parameters, such as entrainment flow rate Q, may be used alternatively. E Entrainment rate η = (Q T -Q N ) / Q N Or tidal volume TotV t NozV t or EntV t Using the disclosed subject matter, the measured patient airway pressure P can be used as a basis for calculation. aw and nozzle flow rate Q N To calculate and / or estimate any and all such values.

[0096] The controllers 140, 440 of the oxygen concentrators 100, 400 and / or the controller 30 of the ventilator 200, and their respective functions, can be implemented using programmable integrated circuit devices such as microcontrollers or control processors. Broadly speaking, the devices can receive certain inputs and, based on these inputs, can generate certain outputs. Specific operations performed in response to the inputs can be programmed as instructions executed by the control processor. For this purpose, the devices may include an arithmetic / logic unit (ALU), various registers, and input / output ports. External memory such as EEPROM (Electrically Erasable / Programmable Read-Only Memory) can be connected to the devices to permanently store and retrieve program instructions, and internal random access memory (RAM) may also be present. For example, in the case of providing an update to an existing device, the computer program for implementing any of the disclosed functions of the controllers 140, 440 and / or the controller 30 can reside on such non-transitory program storage media as well as removable non-transitory program storage media such as semiconductor memory (e.g., an IC card). Examples of program instructions stored on a program storage medium or computer-readable medium may include, in addition to code that can be executed by a processor, status information that can be executed by programmable circuitry such as a field-programmable gate array (FPGA) or a programmable logic device (PLD).

[0097] The above description is given by way of example and not limitation. In view of the above disclosure, those skilled in the art can devise variations within the scope and spirit of the invention disclosed herein. Furthermore, various features of the embodiments disclosed herein can be used individually or in different combinations thereof, and are not intended to be limited to the specific combinations described herein. Therefore, the scope of the claims is not limited to the embodiments shown.

Claims

1. A system for determining the total flow rate of gas and entrained air delivered to a patient by a ventilator, the system comprising: A module for measuring the flow rate of gas discharged from one or more nozzles connected to a patient ventilation interface of a ventilator, the patient ventilation interface including, in addition to the one or more nozzles, one or more orifices for entraining additional ambient air for delivery to the patient; A module for measuring pressure in the patient's ventilation interface; as well as The module determines the total flow rate based on measured flow rate and measured pressure, wherein the total flow rate includes the flow rate of gas discharged from the one or more nozzles and the entrained flow rate of ambient gas carried by the one or more nozzles through the one or more orifices; Store one or more constants associated with each of the multiple nozzle geometries. Wherein, one or more nozzles have a nozzle geometry corresponding to one of a plurality of nozzle geometries, and The determination of total flow rate includes calculating the total flow rate based on measured flow rate, measured pressure, and one or more stored constants associated with the nozzle geometry of one or more nozzles.

2. The system according to claim 1, wherein, For each of a plurality of nozzle geometries, one or more associated constants are stored in a memory disposed in the patient ventilation interface of the nozzle having said nozzle geometry, and The calculation of total flow rate includes reading one or more constants stored in the patient ventilation interface connected to the ventilator.

3. The system of claim 1, further comprising: A signal is transmitted to the oxygen concentrator based on the determined total flow rate.

4. The system of claim 1, further comprising: The total inhaled tidal volume is calculated by integrating the determined total flow rate over time.

5. The system of claim 4, further comprising: The signal is transmitted to the oxygen concentrator based on the calculated total inhaled tidal volume.

6. The system according to claim 1, further comprising: The amount of inhaled tidal gas from the gas discharged through one or more nozzles is calculated by integrating the measured flow rate with respect to time. The amount of entrained tidal air is calculated by integrating the entrained flow rate with respect to time. The entrained flow rate is the difference between the determined total flow rate and the measured flow rate. as well as The patient's inhaled oxygen fraction (%FiO2) is calculated based on the inhaled tidal volume of gas expelled from one or more nozzles and the inhaled tidal volume of entrained air.

7. The system of claim 6, further comprising: The signal is transmitted to the oxygen concentrator based on the calculated %FiO2.

8. A non-transitory program storage medium storing instructions executable by a processor or programmable circuitry thereon to perform operations for controlling an oxygen concentrator based on the total flow rate of gas delivered to a patient by a ventilator and entrained air, said operations including: Measure the flow rate of gas expelled from one or more nozzles connected to a patient ventilation interface of a ventilator, the patient ventilation interface including, in addition to the one or more nozzles, one or more orifices for entraining additional ambient air for delivery to the patient; Measure the pressure in the patient's ventilation port; as well as The total flow rate is determined based on measured flow rate and measured pressure, and the total flow rate includes the flow rate of gas discharged from the one or more nozzles and the entrainment flow rate of ambient gas carried by the one or more nozzles through the one or more orifices; Store one or more constants associated with each of the multiple nozzle geometries. Wherein, one or more nozzles have a nozzle geometry corresponding to one of a plurality of nozzle geometries, and The determination of total flow rate includes calculating the total flow rate based on measured flow rate, measured pressure, and one or more stored constants associated with the nozzle geometry of one or more nozzles.

9. A ventilator, comprising: The non-transitory program storage medium according to claim 8; A processor or programmable circuit used to execute instructions; Flow sensor; as well as Pressure sensor, among which Measuring flow rate involves communicating with a flow sensor, and Pressure measurement includes communication with a pressure sensor.

10. A ventilation system, comprising: The ventilator according to claim 9; as well as The oxygen concentrator connected to the ventilator, wherein The operation also includes transmitting a signal from the ventilator to the oxygen concentrator based on the determined total flow rate.

11. The vent system of claim 10, wherein, The oxygen concentrator includes a controller operable to generate a control signal in response to a signal transmitted from a ventilator, the control signal generated by the controller selectively allowing pressurized ambient air to flow into the product tank of the oxygen concentrator.

12. The vent system of claim 11, wherein, The control signal generated by the controller operates the valve unit of the oxygen concentrator to maintain a preset oxygen concentration in the product tank according to the signal transmitted from the ventilator.

13. The vent system of claim 12, wherein, The control signal generated by the controller operates the valve unit to allow pressurized ambient air to bypass one or more screen beds of the oxygen concentrator.

14. The vent system of claim 11, wherein, The control signal generated by the controller operates the compressor of the oxygen concentrator to maintain a preset oxygen concentration in the product tank according to the signal transmitted from the ventilator.

15. The vent system of claim 11, wherein, The control signal generated by the controller operates the compressor outside the oxygen concentrator to maintain a preset oxygen concentration in the product tank according to the signal transmitted from the ventilator.

16. The vent system of claim 10, wherein, The operation also includes: For each of multiple measurements of the flow rate of gas expelled from one or more nozzles connected to the patient ventilation interface of the ventilator, multiple measurements of the total flow rate corresponding to multiple measurements of the pressure in the patient ventilation interface are stored. The determination of total flow includes estimating total flow based on a comparison of the measured pressure with multiple measured values ​​of total flow stored for the measured flow.

17. A system for estimating the fractional oxygen (%FiO2) inhaled by a patient receiving ventilatory support from a ventilator, the system comprising: A module that stores multiple measurements of %FiO2 corresponding to multiple measurements of pressure in the patient ventilation interface for each of multiple measurements of the flow rate of gas discharged from one or more nozzles connected to the patient ventilation interface of the ventilator. A module for measuring the flow rate of gas discharged from one or more nozzles, the patient ventilation interface including, in addition to the one or more nozzles, one or more orifices for entraining additional ambient air for delivery to the patient; A module for measuring pressure in the patient's ventilation interface; as well as A module that estimates a patient's %FiO2 based on a comparison of measured pressure with multiple measurements of %FiO2 stored for measured flow rate.

18. The system of claim 17, further comprising: The signal is transmitted to the oxygen concentrator based on the estimated %FiO2.

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