Venturi jet with variable throat

Abstract

A variable throat venturi jet for delivering ventilation gas to a patient includes a jet nozzle, a deformable throat body configured to receive the ventilation gas output by the jet nozzle and defining a gas inlet and a gas outlet, and an outer housing containing the deformable throat body. The outer housing can define an entrainment opening open to ambient air and a pilot pressure hole for pressurizing a pressure stabilization chamber between an outer wall of the deformable throat body and an inner wall of the outer housing. A pilot pressure line can be fluidly coupled to the pilot pressure hole. A controller can be programmable to activate the pilot pressure line to compress the deformable throat body during an expiratory phase of positive end-expiratory pressure (PEEP) therapy.

Description

Background Technology

[0001] Non-invasive open ventilation (NIOV), which keeps the patient's airway open rather than closed with a mask, offers minimal disruption to daily activities and is therefore highly beneficial for patients with chronic obstructive pulmonary disease (COPD) and other respiratory conditions. However, because patients can exhale freely, there is no easy way to generate positive end-expiratory pressure (PEEP) for NIOV patients, and generating PEEP typically requires delivering a high flow rate of gas, usually air and / or oxygen. Just like the energy used to generate PEEP, the gas consumed in generating PEEP is wasted. This results in larger, heavier devices and shorter battery life. The required gas flow rate can be reduced using pneumatic (e.g., lift) valves or eliminated entirely by using electrically controlled valves. However, such valves are bulky, adding to the complexity and weight of the device, introducing dead space that increases carbon dioxide rebreathing, and requiring an undesirable, large component placed close to the patient's face. Summary of the Invention

[0002] This invention considers various systems and methods that overcome the aforementioned deficiencies of associated technologies. One aspect of this invention is a Venturi jet tube for delivering ventilation gas to a patient via a variable larynx. The Venturi jet tube may include a jet nozzle, a deformable larynx body configured to receive ventilation gas output from the jet nozzle and define a gas inlet and a gas outlet, and a housing accommodating the deformable larynx body. The housing may define an entrainment opening open to ambient air and a pilot pressure orifice for pressurizing a pressure chamber between the outer wall of the deformable larynx body and the inner wall of the housing.

[0003] When the pressure stabilizing chamber is in the first pressurization state, the venturi jet tube with a variable throat can achieve a jet nozzle pressure P n For 10.5 psig and jet nozzle flow rate V' n When the pressure is less than or equal to 30 slpm, the shut-off pressure P at the gas outlet reaches at least 55 cmH2O. shutoff When the pressure stabilizing chamber is in the second pressurization state, the venturi jet tube with a variable throat can achieve a flow rate V' at the jet nozzle. n When the pressure is less than 10 slpm, for example less than 5 slpm, the gas outlet pressure P that reaches 10 cmH2O is achieved. aw When the pressure stabilizing chamber is in the first pressurization state, the ratio A of the cross-sectional area of ​​the deformable throat body to the cross-sectional area of ​​the jet nozzle is... t / A n It can be 20-30. When the pressure stabilizing chamber is in the second pressurization state, the ratio A t / A n It can be 2.0 to 5.0.

[0004] The deformable throat body can be configured to receive ventilation gas output from the jet nozzle through the entrainment opening of the outer shell.

[0005] Another aspect of this invention is a patient ventilation interface. This patient ventilation interface may include the aforementioned Venturi jet of the deformable larynx and a nasal coupler for fluidly coupling the gas outlet of the deformable larynx body to the patient's nasal cavity. The nasal coupler may include a nasal pillow.

[0006] Another aspect of this invention is a non-invasive ventilation system. This non-invasive ventilation system may include the aforementioned patient ventilation interface and a pilot pressure line fluidly coupled to a pilot pressure orifice. The non-invasive ventilation system may include a controller programmed to activate the pilot pressure line during the expiratory phase of positive end-expiratory pressure (PEEP) therapy to compress the deformable larynx body. The non-invasive ventilation system may include a multi-lumen tube having a ventilation gas chamber terminating at a nozzle and a pilot pressure chamber in fluid communication with the pilot pressure line.

[0007] Another aspect of the present invention is a method for altering the ratio between the diameter of the larynx and the diameter of the jet nozzle in a venturi jet tube for delivering ventilation gas to a patient. The method may include providing a deformable larynx body configured to receive ventilation gas output from the jet nozzle and ambient air entrained through an entrainment opening, the deformable larynx body defining a gas inlet and a gas outlet. The method may further include pressurizing a pressure chamber between an outer wall of the larynx body and an inner wall of a housing accommodating the deformable larynx body to compress the deformable larynx body.

[0008] Pressurizing the pressure chamber may include activating a pilot pressure line fluidly coupled to a pilot pressure orifice defined by the housing. Activation of the pilot pressure line may be performed during the expiratory phase of positive end-expiratory pressure (PEEP) therapy.

[0009] Pressurizing the pressure stabilizing chamber may include pressurizing the pressure stabilizing chamber from a first pressurization state to a second pressurization state. When in the first pressurization state, the venturi jet of the variable throat is at a jet nozzle pressure P. n For 10.5 psig and jet nozzle flow rate V' n When the pressure is less than or equal to 30 slpm, a shut-off pressure P of at least 55 cmH2O is required at the gas outlet. shutoff And when in the second pressurization state, the venturi jet of the variable throat at the jet nozzle flow rate V' n When the pressure is less than 10 slpm, for example, 5 slpm, the gas outlet pressure P that reaches 10 cmH2O is achieved. aw When the pressure stabilizing chamber is in the first pressurization state, the ratio A of the cross-sectional area of ​​the deformable throat body to the cross-sectional area of ​​the jet nozzle is... t / An It can be 20-30. When the pressure stabilizing chamber is in the second pressurization state, the ratio A t / A n It can be 2.0 to 5.0.

[0010] Another aspect of this invention is a Venturi jet tube for delivering ventilation gas to a patient using a variable larynx. This variable larynx Venturi jet tube may include a jet nozzle, a deformable larynx body configured to receive ventilation gas output from the jet nozzle and ambient air entrained through an entrainment opening and defining a gas inlet and a gas outlet, and a housing accommodating the deformable larynx body. The housing may define a pilot pressure orifice for pressurizing a pressure chamber between the outer wall of the deformable larynx body and the inner wall of the housing.

[0011] When the pressure stabilizing chamber is in the first pressurization state, the venturi jet pipe of the variable throat can reach a jet nozzle pressure P. n For 10.5 psig and jet nozzle flow rate V' n The shut-off pressure P of the gas outlet with at least 55 cmH2O at a time of 30 slpm or less shutoff When the pressure stabilizing chamber is in the second pressurization state, the venturi jet tube with a variable throat can achieve a flow rate V' at the jet nozzle. n When the pressure is less than 10 slpm, for example less than 5 slpm, the gas outlet pressure P that reaches 10 cmH2O is achieved. aw When the pressure stabilizing chamber is in the first pressurization state, the ratio A of the cross-sectional area of ​​the deformable throat body to the cross-sectional area of ​​the jet nozzle is... t / A n It can be 20-30. When the pressure stabilizing chamber is in the second pressurization state, the ratio A t / A n It can be 2.0 to 5.0. Attached Figure Description

[0012] These and other features and advantages of the various embodiments of the invention herein will be better understood from the following description and accompanying drawings, in which similar numerals refer to similar parts throughout:

[0013] Figure 1 An exemplary non-invasive ventilation system according to an embodiment of the present invention is shown, with a Venturi jet tube of the system with a variable larynx shown in a cross-sectional view;

[0014] Figure 2A A cross-sectional view of the Venturi jet pipe of the variable throat in the pressure stabilizing chamber under the first pressurization state;

[0015] Figure 2B A cross-sectional view of the Venturi jet pipe of the variable throat in the pressure stabilizing chamber under the second pressurization state;

[0016] Figure 3A A perspective view of a Venturi jet with a variable throat;

[0017] Figure 3B An exploded view of the components of a venturi jet with a variable throat.

[0018] Figure 3C Component anatomical view of the Venturi jet tube with variable larynx;

[0019] Figure 4 The geometry of four exemplary candidate venturi tubes in relaxed and compressed states corresponding to the first and second pressurized chamber states is shown; and

[0020] Figure 5 The performance characteristics of an exemplary variable throat Venturi jet are depicted in graphical form. Detailed Implementation

[0021] This invention includes various embodiments of a Venturi jet tube with a variable larynx for delivering ventilation gas to a patient, and systems and methods for changing the ratio between the larynx diameter and the jet nozzle diameter. The specific embodiments listed below with reference to the accompanying drawings are intended as descriptions of several currently contemplated embodiments and are not intended to represent the only form in which the invention can be developed or utilized. This specification sets forth functions and features relating to illustrative embodiments. However, it should be understood that the same or equivalent functions can be achieved through different embodiments also intended to be included within the scope of this invention. It should be further 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 such entities.

[0022] Figure 1An exemplary noninvasive ventilation system 10 according to an embodiment of the present invention is shown, comprising a patient ventilation interface 20 including a venturi jet 100 of a variable larynx for delivering ventilation gas to a patient. Due to the increased velocity and decreased pressure of the ventilation gas under compression in the venturi jet 100 of the variable larynx, ambient air is entrained through one or more entrainment orifices 133. By amplifying the ventilation gas output from the jet nozzle 110 in this way, the venturi jet 100 of the variable larynx can act as a highly efficient flow generator when providing ventilation therapy to a patient. Simultaneously, to enable the venturi jet 100 of the variable larynx to act as a highly efficient PEEP generator, the venturi jet 100 of the variable larynx may include a deformable larynx body 120 for compression, and a housing 130 of the venturi jet 100 defines a pilot pressure orifice 135 (e.g., via a supply and vent circuit) for pressurizing a pressure chamber 140 surrounding the deformable larynx body 120. By selectively pressurizing the pressure chamber 140, the pressure chamber 140 can switch between a first pressurized state that maximizes airflow to the patient (e.g., during inspiration) and a second pressurized state that further compresses the deformable larynx body 120. In the latter state, the cross-sectional area of ​​the deformable larynx body 120 is reduced, which significantly reduces the nozzle flow required to achieve the desired output pressure, enabling efficient PEEP generation.

[0023] like Figure 1As shown, for example, the patient ventilation interface 20 of the integrated variable larynx ventilator 100 can be a nasal interface with a pair of nasal couplers 24 (e.g., nasal pillows) for coupling the gas outlet fluid of the deformable larynx body 120 to the patient's nasal cavity. Examples of such nasal interfaces are described in U.S. Patent No. 9,132,250, entitled "Noninvasive ventilation method, system, and device including a noninvasive ventilation interface with clamping orifice and / or pressure features"; U.S. Patent No. 9,675,774, entitled "Noninvasive open ventilation method, system, and device having a gas delivery nozzle in free space"; U.S. Patent No. 9,962,512, entitled "Noninvasive ventilation method, system, and device including an unsealed ventilation interface with a free space nozzle feature"; and U.S. Patent No. 10,792,449, entitled "Patient interface with integrated jet pump," the entire contents of which are clearly incorporated herein by reference. For example, the variable larynx Venturi jet 100 may be configured in or constitute a manifold assembly 22 of the patient ventilation interface 20, with the jet nozzle 110 integrated with or attached to one end of the manifold assembly 22. The manifold assembly 22 may be configured to mate between the patient's nose and upper lip and may be used to direct outlet flow from the variable larynx Venturi jet 100 to the patient's nostrils.

[0024] refer to Figure 1 As shown in the figure, it is conceivable that the variable laryngeal venturi jet 100 can be integrated only on one side of the manifold assembly 22 or otherwise disposed on one side of the manifold assembly 22, with its outlet flow directed simultaneously to both nostrils of the patient. Following these principles, as described above, the manifold assembly 22 of the patient ventilation interface 20 can be equipped with a spaced-apart, identically configured pair of nasal couplers 24 (e.g., nasal pillows) that can engage with and be placed in fluid communication with the respective nostril, and the manifold assembly 22 can place the variable laryngeal venturi jet 100 in the nasal coupler 24 through a single flow channel in fluid communication with the nasal coupler 24. Alternatively, the manifold 22 can define separate flow channels for the left and right nostrils of each patient, in which case, for each side of the manifold 22, some or all of the features of the variable laryngeal venturi jet 100 and the variable laryngeal venturi jet 100 described herein can be completely identical.

[0025] To provide pressurization of the pressure chamber 140 as described above, the noninvasive ventilation system 10 may include a pilot pressure line 30 fluidly coupled to a pilot pressure orifice 135. A programmable controller 40 is configured to activate the pilot pressure line 30 during the expiratory phase of PEEP therapy to compress the deformable larynx body 120. In an illustrative example, the noninvasive ventilation system 10 may include a multilumen tube 50 having a ventilation gas chamber 52 terminating at a jet nozzle 110, and a pilot pressure chamber 54 in fluid communication with the pilot pressure line 30. For example, the ventilation gas chamber 52 may receive ventilation gas from a ventilator or oxygen concentrator. The pilot pressure line 30 may extend forward from the multilumen tube 50, through the jet nozzle 110, to the pilot pressure orifice 135 of the Venturi jet tube 100 of the deformable larynx.

[0026] For example, additional lumens of the multi-lumen tube 50 may include, for example, a low-pressure oxygen gas chamber (which may terminate near the low-pressure jet nozzle outlet of the jet nozzle 110), a pressure sensing chamber (e.g., which may extend further downward to terminate closer to the patient's nostril, such as at the bottom of the nasal coupler 24 of the Venturi jet tube 100 closest to the variable larynx), a medication chamber, etc. However, it is contemplated that, in a preferred embodiment, a second tube 50 may be provided that routes one or more of these lumens to the other side of the manifold assembly 22 (i.e., the opposite side in which the variable larynx Venturi jet tube 100 is integrated). Such a pair of tubes 50 can branch upstream from a single multi-lumen tube using a wye connector, as described in U.S. Patent No. 10,792,449, which is incorporated herein by reference. For example, Figure 1 As shown, the second tube 50 has a pressure-sensing cavity 56 as its sole cavity, which extends to the bottom of one of the nasal couplers 24 to properly measure the pressure downstream of the venturi jet tube 100 of the variable larynx. In this example, the first tube 50 would not have a pressure-sensing cavity. Following these principles, it is conceivable that any of the aforementioned cavities can be provided individually or in some specified combination on one or both sides of the interface 20, either by using the first tube 50 and the second tube 50, or by using the first tube 50 but not the second tube 50.

[0027] In cases where the noninvasive ventilation system 10 may consist of only a single multi-lumen tube 50 extending to the patient ventilation interface 20, it is also conceivable that the multi-lumen tube 50 may engage with the manifold 22 at a central location equidistant from the nasal coupler 24. For example, as Figure 1As shown, the multi-lumen tube 50 can be connected to the bottom or front of the manifold 22 located between the nasal couplers 24. In this case, the same central region near the bottom of the nasal coupler 24 can accommodate a single variable laryngospheric venturi jet 100 supplied by the multi-lumen tube 50, and the output flow of the single variable laryngospheric venturi jet 100 is simultaneously directed to both nasal couplers 24. As another possibility, the invented variable laryngospheric venturi jet 100 can be embodied in a detachable connector that engages the multi-lumen tube 50 with a mask or other patient interface at any suitable location (and in some cases, the detachable connector can be universally adapted to multiple different patient interfaces). An example of such a connector that can be equipped with the invented variable throat Venturi jet tube 100 is an adapter disclosed in U.S. Patent No. 10,307,552 entitled “Jet Pump Adapter for Ventilation Systems,” the entire contents of which are clearly incorporated herein by reference.

[0028] For example, controller 40 may be a separate device dedicated to activating pilot pressure line 30 during PEEP therapy (e.g., based on sensor output indicating the expiratory phase of a patient's breathing) or may be a controller for a ventilator or oxygen concentrator. In this regard, in addition to those components incorporated herein by reference, exemplary ventilators and oxygen concentrators that can be used with embodiments of the invention also include those components described in U.S. Patent No. 10,369,320, entitled "Modular Ventilation System," U.S. Patent Application Publication No. 2019 / 0307981, entitled "Modular Ventilation System," and U.S. Patent Application No. 16 / 874,472, filed May 14, 2020, entitled "O2 Concentrator with Screening Bed Bypass and Method of Control Thereof," the entire contents of each of which are clearly incorporated herein by reference. The controller 40 can activate the pilot pressure line 30 by controlling the pressure in the pilot pressure chamber 54 of the multi-chamber tube 50, for example by controlling a valve in the pilot pressure output port of a ventilator, oxygen concentrator, or other gas source that houses the controller 40 or is connected to the controller 40.

[0029] Figure 2A and Figure 2B A cross-sectional view of the Venturi jet pipe 100 of the variable throat in the pressure stabilizing chamber 140 in the first pressurization state and the second pressurization state. Figures 3A-3C Additional perspective views, exploded views, and dissected views of the components are provided for the venturi jet tube 100 with a variable throat. It can be seen that... Figure 2A and Figure 2BIn this process, as the pressure in the pressure stabilizing chamber 140 increases, the deformable throat body 120 is compressed. Therefore, when the pressure in the pressure stabilizing chamber 140 increases (e.g., by activating the pilot pressure line 30, see...), Figure 1 The pressure regulating chamber 140 is in the first pressurization state ( Figure 2A Switch to the second boost mode. Figure 2B More specifically, the cross-sectional area A of the deformable throat body. t (for example with) Figure 2A and Figure 2B The diameter D in t The corresponding minimum cross-sectional area decreases from the first pressurization state to the second pressurization state. Assume the nozzle has a fixed cross-sectional area A. n (with diameter D) n (corresponding to), then the ratio A t / A n This reduces the nozzle flow rate required to achieve PEEP.

[0030] The deformable throat body 120 can define a gas inlet 122 and a gas outlet 124, and can have a generally tubular shape in a relaxed (e.g., like a molded) state, such as Figure 3B The best illustration is shown below. Flange 126 can be positioned at either end. See again. Figure 2A and Figure 2B When the deformable throat body 120 is housed within the housing 130, the flange 126 can act to position the deformable throat body 120 within a cavity defined in the housing 130. The flange 126 can also be used to indicate the longitudinal extent of the pressure stabilizing chamber 140 between the outer wall 126 of the deformable throat body 120 and the inner wall 137 of the housing 130. Figure 2B As shown, when the pressure chamber 140 is pressurized, the pressure causes the deformable throat body 120 to be compressed about its center, while the flange 126 is firmly held to the inner wall 137 of the housing 130 (with or without adhesive). Thereafter, as... Figure 2A As shown, when the pressure chamber 140 is depressurized, the deformable throat body 120 can return to its relaxed state. For example, the deformable throat body 120 can be a thermoplastic elastomer (TPE) or thermosetting plastic produced by liquid injection molding (LIM) using liquid silicone (LSR).

[0031] For example, as shown, the housing 130 can be assembled from one or more components 132, 134, which are attached to each other by ultrasonic welding. While the components 132, 134 of the housing 130 can be similarly made of thermoplastic or thermosetting plastics, they typically (but not necessarily) have greater rigidity than the deformable throat body 120. In the illustrative example, there is an inlet component 132 and an outlet component 134. More detailed, as... Figures 2A-3C As shown, the inlet portion 132 of the housing 130 includes a generally truncated conical portion that flares outward from the pressure chamber 140 and defines an entrainment opening 136 open to ambient air. The outlet portion 134 includes an inner wall 137 defining the pressure chamber 140, and also includes a generally truncated conical portion that flares outward from the pressure chamber 140 and serves as a conduit for, for example, through a nasal coupler 24 (see...). Figure 1 A diffuser 138 that provides the patient with the required airflow and / or pressure. According to... Figure 1 The setup shown allows the deformable throat body 120 to receive ventilation gas output from the jet nozzle 110 through the entrainment opening 136, in addition to absorbing ambient air through the entrainment orifice 133 of the manifold assembly 22 and also introducing it into the entrainment opening 136. In this respect, as... Figure 1 As shown, the entrainment opening 136 (and subsequently the deformable throat body 120) is in fluid communication with the jet nozzle 110 and entrainment orifice 133 of the manifold assembly 22. The distal end of the jet nozzle 110 may be located outside the entrainment opening 136 as shown, or inside the inlet component 132 downstream of the entrainment opening 136, closer to the gas inlet 122 of the deformable throat body 120. In either case, entrainment of ambient air occurs around the jet nozzle 110.

[0032] In such Figure 1 In the illustrated embodiment, where the manifold assembly 22 includes an entrainment orifice 133 and the distal end of the jet nozzle 110 is radially aligned with a portion of the entrainment orifice 133, it is conceivable that the entrainment opening 136 could similarly be radially aligned with a portion of the entrainment orifice 133, or located downstream thereof. If the distal end of the jet nozzle 110 is positioned within the inlet portion 132 downstream of the entrainment opening 136, the same relative positioning choice between the entrainment opening 136 and the entrainment orifice 133 can be obtained. Although the entrainment orifice 133 is in Figure 1 The entrainment orifice 133 is described as being formed in the manifold assembly 22, but alternatively, it can be formed in a removable nozzle assembly comprising a jet nozzle 110 and rigidly or rotatably engaging with a corresponding end of an alternatively configured manifold assembly without the entrainment orifice 133. Following these principles, it is also conceivable that… Figure 1A variant of the patient ventilation interface 20 shown is provided in which the entrainment opening 136 of the venturi jet tube 100 of the variable larynx can be configured to directly draw in ambient air, in contrast to ambient air being delivered from a separate entrainment orifice or opening, such as entrainment orifice 133. In this case, the ambient air directly drawn into the entrainment opening 136 can flow around the edge of the jet nozzle 110, particularly if the distal end of the jet nozzle 110 is present within an inlet component downstream of the entrainment opening 136. However, in any case, the deformable larynx body 120 is configured to receive ventilation gas output from the jet nozzle 110 and ambient air entrained directly or through the entrainment orifice 133 into the entrainment opening 136 at its gas inlet 122.

[0033] The geometry of the variable ventilator jet 100, including the cross-sectional area of ​​the nozzle 110, can be selected, particularly the geometry of the deformable ventilator body 120 when the pressure chamber 140 is in the first and second pressurization states, to achieve the desired performance characteristics. For ease of illustration, the maximum ventilator output capacity can be specified by the nozzle flow rate V'. n ≤30 slpm, nozzle pressure P n =10.5 psig, which in turn limits the range of possible nozzle diameters. By using each of the multiple possible nozzle diameters, it is possible to achieve this when the deformable throat body 120 is in a relaxed state (e.g., Figure 2A (The pressure stabilizing chamber 140 shown is in the first pressurization state) Test candidate venturi geometry to determine the closing pressure P at the gas outlet 124 of the deformable throat body 120. shutoff and at maximum nozzle pressure P n Maximum output current V' when = 10.5 aw-max This allows us to determine whether the candidate venturi geometry satisfies the required P. shutoff -V' aw-max Performance. Subsequently, when the deformable throat body 120 is in a compressed state (e.g., Figure 2B The pressure stabilizing chamber 140 shown is in a second pressurization state. The same candidate venturi geometry is tested to determine the required PEEP (e.g., P') to achieve this. aw =10cmH2O), the nozzle flow rate V' n And at the same nozzle flow rate V' n Maximum output flow rate V' aw-max .

[0034] When, respectively, the nozzle diameter of the first nozzle 110 is D n = 0.043 inches (cross-sectional area is A) n =0.0015 square inches), the nozzle diameter of the second nozzle 110 is D n = 0.048 inches (cross-sectional area is A)n When the diameter is 0.0018 square inches, Tables 1 and 2 below show exemplary data illustrating the results of such a test procedure. In Tables 1 and 2, the test number “#” is in the form “xy”, where x represents different candidate venturi geometries 1, 2, 3, and 4, and y represents the relaxed state (“1”) and compressed state (“2”) of the deformable throat body 120, as shown below. Figure 4 As shown. The Venturi tube geometry itself is determined by the minimum cross-sectional diameter D of the deformable throat body 120. t (and minimum cross-sectional area A) t The length L from the gas inlet 122 to the gas outlet 124 of the deformable throat body 120 t and the length L from the gas outlet 124 to one end of the diffuser 138. d Limitations. In the example data of Tables 1 and 2, such as... Figure 2A and Figure 2B As shown, it is assumed that the deformable throat body 120 receives ventilation gas output from the jet nozzle 110 through the entrainment opening 136 of the housing 130, and the length between the nozzle 110 and the gas inlet 122 of the deformable throat body 120 is 0.4 inches.

[0035] Table 1

[0036]

[0037]

[0038] Table 2

[0039]

[0040] For each test number "#", an exemplary test procedure for generating data as shown in Tables 1 and 2 can be described as follows. First, the gas outlet 124 (or one end of the diffuser 138) is closed and the nozzle flow rate V' is increased. n Until export pressure P aw Equal to the target PEEP, for example, P shutoff =10cmH2O. Record the nozzle flow rate V' in the first line. n and nozzle pressure P n Then open gas outlet 124 and record the outlet pressure P on the same line. aw and output flow rate V' aw Next, increase the nozzle pressure P. n Set the target maximum value to 10.5 psig. Now record the nozzle flow rate V' in the second line. n Export pressure P aw and output flow rate V' awFinally, gas outlet 124 is closed again, and the maximum nozzle flow V' is recorded in the second line. n Corresponding shut-off pressure P shutoff For different nozzles and candidate venturi geometries, the deformable throat body 120 can be in a relaxed state and a compressed state (with...). Figure 2A and Figure 2B (The first and second states of the pressure stabilizing chamber 140 shown correspond to each other) Repeat this procedure.

[0041] To calculate the maximum output flow rate V' aw-max At the target maximum value P of the nozzle pressure n The output flow rate V' measured at 10.5 psig aw It can be multiplied by the corresponding shut-off pressure P shutoff Divide by the shut-off pressure P shutoff With the corresponding measured outlet pressure P aw The difference is as follows: V' aw-max =V' aw *P shutoff / (P shutoff –P aw Maximum output flow rate V' aw-max With minimum nozzle flow rate V' n The ratio X max The following can be calculated: X max =V' aw-max / V' n .

[0042] Therefore, based on the combined data of the relaxed and compressed states of the deformable throat body 120 for each candidate venturi geometry, the beneficial characteristics are tabulated as shown in Tables 3 and 4 below, with nozzle diameter D. n D respectively n = 0.043 inches and D n = 0.048 inches:

[0043] Table 3

[0044]

[0045] Table 4

[0046]

[0047]

[0048] Table 5 shows the nozzle diameter D of nozzle 110. nAn exemplary Venturi geometry for achieving the desired performance characteristics at a cross-sectional area of ​​0.048 inches (An = 0.0018 square inches), with unused data omitted. Again, it is assumed that the deformable throat body 120 receives ventilation gas output from the jet nozzle 110 through the entrainment opening 136 of the housing 130, with a length of 0.4 inches between the nozzle 110 and the gas inlet 122 of the deformable throat body 120.

[0049] Table 5

[0050]

[0051] Table 6 below summarizes the combined performance characteristics of the relaxed and contracted states of the deformable throat body 120 for the above candidate Venturi tube geometry #5:

[0052] Table 6

[0053]

[0054] As can be seen from Tables 5 and 6 (and as shown in Tables 6 and 6), Figure 5 (Chartically depicted), when the pressure stabilizing chamber 140 is in the first pressurized state (uninflated) corresponding to the relaxed state of the deformable throat body 120, the Venturi jet tube 100 with the variable throat having candidate geometry #5 is at the jet nozzle pressure P n For 10.5 psig and jet nozzle flow rate V' n When the gas concentration is 24.3 slpm (which is less than or equal to 30 slpm), the shut-off pressure P at the gas outlet 124 reaches 57.0 cmH2O (meeting the target performance characteristic of at least 55 cmH2O). shutoff The maximum output stream V' was achieved. aw-max =96.1. Simultaneously, when the pressure stabilizing chamber 140 is in the second pressurized state (inflated) corresponding to the deformable throat body 120, the Venturi jet pipe 100 of the same variable throat achieves a jet nozzle flow rate V' n PEEP (gas outlet pressure P) at 4.3 slpm aw =10cmH2O). Therefore, by using a Venturi jet tube with a variable throat having the deformable throat body 120 described herein, PEEP (e.g., gas outlet pressure P) is achieved. aw =10cmH2O) can be used in jet nozzle flow rate V' n This is achieved at less than 10 slpm, which is less than half of the 20 slpm typically required by conventional NIOV equipment, and in some cases, it can be achieved at a jet nozzle flow rate V' nThis is achieved at less than 5 slpm, which is less than a quarter of the usual requirement. However, it is worth noting that, at the time of invention, activating the pilot pressure line 30 used in some embodiments of the inventive deformable throat body 120 can use some airflow, such as 1 slpm.

[0055] Equivalence tests can be performed to select a Venturi geometry that meets any design constraints of the patient interface 20, such as one or more entrainment openings 136 being adjacent to the jet nozzle 110, and / or the lengths between the nozzle 110 and the gas inlet 122 of the deformable larynx body 120 being different. Following these principles, Venturi geometries can be selected to meet different performance characteristics, including, in addition to nozzle flow rate V' n ≤30slpm and nozzle pressure P n = Different maximum ventilator output capacities other than 10.5 psig, different PEEPs other than 10 mmH2O, at maximum nozzle pressure P n Different target closing pressures P at different times shutoff and maximum output flow V' aw-max wait.

[0056] The controller 40 of the non-invasive ventilation system 10 (which may be the controller of an oxygen concentrator or ventilator as indicated above) can be implemented by a programmable integrated circuit device, such as a microcontroller or control processor. Broadly speaking, the device can receive certain inputs and can generate certain outputs based on those inputs. Specific operations performed on the inputs can be programmed as instructions executed by the control processor. In this regard, the device 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 device 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, a computer program for implementing any inventive function of the controller 40 may reside in such a non-transitory program storage medium, as well as a removable non-transitory program storage medium, such as semiconductor memory (e.g., an IC card). Examples of program instructions stored on a program storage medium or computer-readable medium, in addition to code executable by a processor, may also include status information executed by programmable circuitry, such as a field-programmable gate array (FPGA) or a programmable logic device (PLD).

[0057] In the above example, the venturi jet 100 of the variable throat is realized by a deformable throat body 120, the cross-sectional area of ​​which is A. t The fixed cross-sectional area A relative to the jet nozzle 110 nSelective alteration. However, it is also conceivable to replace or exclude the cross-sectional area A of the deformable throat body 120. t In addition, the cross-sectional area A of the jet nozzle 110 n The cross-sectional area A of the jet nozzle 110 can be selectively reduced or increased. For example, the cross-sectional area A of the jet nozzle 110 can be selectively changed by pressurizing the inflatable bag by rotating the conical pin along the axial direction of the nozzle 110 or by pressurizing the inflatable bag using a pressure stabilizing chamber 140 similar to that described above. n As another possibility, two jet nozzles 110 can be used, one for achieving low nozzle flow rate V'. n PEEP at that time, another one used to achieve the required P shutoff -V' aw-max Performance. The candidate jet nozzle diameter D used with the embodiments of the invention. t Exemplary data is shown in Table 7, as follows:

[0058] Table 7

[0059]

[0060] For ease of explanation, the above invention assumes that the venturi jet 100 with a variable throat has a single jet nozzle 110. Therefore, the cross-sectional area A n Described as having a diameter D with respect to the jet nozzle 110 n Correspondingly. However, the invention is not limited thereto. For example, the venturi jet 100 with a variable throat may include a plurality of jet nozzles arranged in annular or other forms. In this case, the cross-sectional area A n This can refer to the total cross-sectional area of ​​multiple jet nozzles 110, used to evaluate A. t / A n The ratio of .

[0061] The above description is merely illustrative and not intended to be limiting. Based on the above invention, variations within the scope and spirit of the invention as described herein will be apparent to those skilled in the art. Furthermore, the various features of the embodiments described 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 illustrative embodiments.

Claims

1. A Venturi jet tube with a variable larynx for delivering ventilation gas to a patient, the Venturi jet tube with a variable larynx comprising: Jet nozzle; A deformable throat body, the deformable throat body being configured to receive ventilation gas output from the jet nozzle and to define a gas inlet and a gas outlet; as well as A housing accommodating the deformable throat body, the housing defining a pilot pressure orifice for pressurizing a pressure-regulating chamber between the outer wall of the deformable throat body and the inner wall of the housing; the housing having an outwardly flared portion away from the pressure-regulating chamber and defining an entrainment opening configured to directly draw in ambient air therein, the deformable throat body being configured to receive ventilation gas output from the jet nozzle through the entrainment opening of the housing.

2. The venturi jet tube with a variable throat according to claim 1, wherein, When the pressure stabilizing chamber is in the first pressurization state, the venturi jet of the variable throat is at the jet nozzle pressure P n For 10.5 psig and jet nozzle flow rate V' n When the gas concentration is less than or equal to 30 slpm, the shut-off pressure P at the gas outlet reaches at least 55 cmH2O. shutoff And when the pressure stabilizing chamber is in the second pressurization state, the venturi jet of the variable throat is at the jet nozzle flow rate V' n When the gas outlet pressure P reaches 10 cmH2O at a concentration less than 10 slpm, the gas outlet pressure is P. aw .

3. The venturi jet tube with a variable throat according to claim 2, wherein, When the pressure stabilizing chamber is in the second pressurization state, the venturi jet of the variable throat is at the jet nozzle flow rate V' n Gas outlet pressure P less than 5 slpm to reach 10 cmH2O aw .

4. The venturi jet tube with a variable throat according to claim 2, wherein, When the pressure stabilizing chamber is in the first pressurized state, the ratio A of the cross-sectional area of ​​the deformable throat body to the cross-sectional area of ​​the jet nozzle is... t / A n The ratio A is 20-30, and when the pressure stabilizing chamber is in the second pressurization state, the ratio A is... t / A n The value ranges from 2.0 to 5.

0.

5. The venturi jet tube with a variable throat according to claim 1, wherein, The deformable throat body is configured to receive the ventilation gas output by the jet nozzle through the entrainment opening of the housing.

6. A patient ventilation interface, comprising: The venturi jet tube with a variable throat as described in claim 1; as well as A nasal coupler for coupling the gas outlet fluid of a deformable larynx body to the patient's nasal cavity.

7. The patient ventilation interface according to claim 6, wherein, The nasal coupler includes a nasal pillow.

8. A non-invasive ventilation system, comprising: The patient ventilation interface according to claim 6; as well as A pilot pressure line, wherein the pilot pressure line is fluid-coupled to a pilot pressure orifice.

9. The noninvasive ventilation system of claim 8, further comprising a controller programmed to activate a pilot pressure line to compress the deformable larynx body during the expiratory phase of positive end-expiratory pressure (PEEP) therapy.

10. The non-invasive ventilation system according to claim 8, further comprising a multi-lumen tube having a ventilation gas chamber terminating at a nozzle, and a pilot pressure chamber in fluid communication with a pilot pressure line.

11. A system for altering the ratio between the diameter of the larynx and the diameter of the jet nozzle in a venturi jet tube for delivering ventilation gas to a patient, the system comprising: A deformable throat body is configured to receive ventilation gas output from a jet nozzle, the deformable throat body defining a gas inlet and a gas outlet; as well as The controller is programmed to pressurize a pressure chamber between the outer wall of the throat body and the inner wall of the housing containing the deformable throat body to compress the deformable throat body; the housing has an outwardly flared portion away from the pressure chamber and defines an entrainment opening configured to directly draw in ambient air therein, and the deformable throat body is configured to receive ventilation gas output from the jet nozzle through the entrainment opening of the housing.

12. The system according to claim 11, wherein, The pressurization of the pressure chamber includes activating a pilot pressure line that is fluid-coupled to a pilot pressure orifice defined by the housing.

13. The system according to claim 12, wherein, The activation is performed during the expiratory phase of positive end-expiratory pressure (PEEP) therapy.

14. The system according to claim 11, wherein, The pressurization includes pressurizing the pressure stabilizing chamber from a first pressurization state to a second pressurization state. When in the first pressurization state, the venturi jet of the variable throat has a jet nozzle pressure Pn of 10.5 psig and a jet nozzle flow rate V'. n When the gas concentration is less than or equal to 30 slpm, the shut-off pressure P at the gas outlet reaches at least 55 cmH2O. shutoff And when in the second pressurization state, the venturi jet of the variable throat at the jet nozzle flow rate V' n When the gas outlet pressure P reaches 10 cmH2O at a concentration less than 10 slpm, the gas outlet pressure is P. aw .

15. The system according to claim 14, wherein, When the pressure stabilizing chamber is in the second pressurization state, the venturi jet of the variable throat is at the jet nozzle flow rate V' n When the gas outlet pressure P reaches 10 cmH2O at less than 5 slpm, it is considered to be less than 5 slpm. aw .

16. The system according to claim 14, wherein, When the pressure stabilizing chamber is in the first pressurized state, the ratio A of the cross-sectional area of ​​the deformable throat body to the cross-sectional area of ​​the jet nozzle is... t / A n The ratio A is 20-30, and when the pressure stabilizing chamber is in the second pressurization state, the ratio A is... t / A n The value ranges from 2.0 to 5.

0.

17. A venturi jet tube with a variable larynx for delivering ventilation gas to a patient, the venturi jet tube with a variable larynx comprising: Jet nozzle; A deformable throat body, the deformable throat body being configured to receive ventilation gas output from the jet nozzle and ambient air entrained through the entrainment opening and defining a gas inlet and a gas outlet; and A housing accommodating the deformable throat body, the housing defining a pilot pressure orifice for pressurizing a pressure-regulating chamber between the outer wall of the deformable throat body and the inner wall of the housing; the housing having an outwardly flared portion away from the pressure-regulating chamber and defining an entrainment opening configured to directly draw in ambient air therein, the deformable throat body being configured to receive ventilation gas output from the jet nozzle through the entrainment opening of the housing.

18. The venturi jet tube with a variable throat according to claim 17, wherein, When the pressure stabilizing chamber is in the first pressurization state, the venturi jet of the variable throat is at the jet nozzle pressure P n For 10.5 psig and jet nozzle flow rate V' n When the gas concentration is less than or equal to 30 slpm, the shut-off pressure P at the gas outlet reaches at least 55 cmH2O. shutoff And when the pressure stabilizing chamber is in the second pressurization state, the venturi jet of the variable throat is at the jet nozzle flow rate V' n When the pressure is less than 10 slpm, the gas outlet pressure P that reaches 10 cmH2O is achieved. aw .

19. The venturi jet tube with a variable throat according to claim 18, wherein, When the pressure stabilizing chamber is in the second pressurization state, the venturi jet of the variable throat is at the jet nozzle flow rate V' n When the gas outlet pressure P reaches 10 cmH2O at less than 5 slpm, it is considered to be less than 5 slpm. aw .

20. The venturi jet tube with a variable throat according to claim 18, wherein, When the pressure stabilizing chamber is in the first pressurized state, the ratio A of the cross-sectional area of ​​the deformable throat body to the cross-sectional area of ​​the jet nozzle is... t / A n The ratio A is 20-30, and when the pressure stabilizing chamber is in the second pressurization state, the ratio A is... t / A n The value ranges from 2.0 to 5.0.

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