Ventilation interface, non-invasive ventilation system and method, method of correcting airway pressure

Abstract

A patient ventilation interface has a throat body defining a venturi throat open to ambient air, a nasal pillow disposed about the venturi throat to define a plenum chamber between the venturi throat and the nasal pillow, a nozzle arranged to output ventilation gas to the venturi throat, and a pressure sensing tube having a pressure sensing port positioned in fluid communication with the plenum chamber. The nasal pillow is an integral part of the throat body. An expected error in a sensed patient airway pressure P sense and a nozzle flow rate V' n of the nozzle can be corrected by applying a correction factor P delta indexed to the sensed patient airway pressure P sense . Delivery of ventilation gas output by the nozzle can be controlled in response to the corrected patient airway pressure.

Description

Technical Field

[0001] This disclosure generally relates to devices and methods for performing noninvasive ventilation (NIV) therapy, and more specifically, to an improved nasal pillow patient ventilation interface with integrated pressure sensing capabilities, which is less prone to errors caused by increased flow rate. Background Technology

[0002] For noninvasive ventilation (NIV) to be administered to patients with chronic obstructive pulmonary disease (COPD) or other respiratory conditions, patient comfort is ideally achieved through a physically small nasal pillow interface. Unlike larger components such as nasal masks or full-face masks, a nasal pillow is primarily confined within and immediately below the patient's nostrils, without significantly obstructing the patient's face. For the same reason, given that understanding the actual pressure in the patient's airway is crucial for proper NIV function and compliance with international standards for medical devices, it would be beneficial to integrate pressure sensing within the boundaries of the nasal pillow to minimize the overall burden on the interface. However, significant obstacles exist when it comes to integrating pressure sensing functionality with nasal pillows. Generally, due to Bernoulli's principle, sensing pressure in areas of airflow is prone to error as flow velocity increases. This problem becomes particularly acute when attempting to perform accurate pressure measurements within the small volume formed by the nasal pillow. This disclosure envisions various systems and methods for overcoming the aforementioned deficiencies of the accompanying related technologies. Summary of the Invention

[0003] One aspect of embodiments of this disclosure is a patient ventilation interface, such as a nasal pillow interface. The patient ventilation interface may include: a throat body defining a venturi throat open to ambient air; a nasal pillow disposed around the venturi throat to define an inflation chamber between the venturi throat and the nasal pillow; a nozzle arranged to deliver ventilation gas to the venturi throat; and a pressure sensing tube having a pressure sensing port positioned in fluid communication with the inflation chamber.

[0004] The nasal pillow may be a component of the laryngeal body. The inflation chamber may have a crescent-shaped cross-section. The venturi laryngeal portion may be tapered outwards away from the nozzle. The laryngeal body may have greater rigidity than the nasal pillow. The outer surface of the laryngeal body may be splined. The patient ventilation interface may include a ventilation gas tube terminating at the nozzle. At least a portion of a pressure sensing tube may be disposed within the ventilation gas tube. The pressure sensing tube may extend from the ventilation gas tube into the laryngeal body to position a pressure sensing port in fluid communication with the inflation chamber. The pressure sensing port of the pressure sensing tube may be in fluid communication with the inflation chamber through a pressure sensing channel defined by the laryngeal body.

[0005] Another aspect of the embodiments of this disclosure is a patient ventilation interface, which may include: a laryngeal body defining a venturi larynx open to ambient air, a nasal pillow disposed around the laryngeal body to define an annular inflation chamber between the laryngeal body and a nasal pillow, a nozzle arranged to deliver ventilation gas to the venturi larynx, and a pressure sensing tube having a pressure sensing port positioned in fluid communication with the annular inflation chamber.

[0006] The laryngeal body may have greater rigidity than the nasal occiput. The outer surface of the laryngeal body may be splined. The patient ventilation interface may include a ventilation gas tube terminating at a nozzle. At least a portion of a pressure sensing tube may be disposed within the ventilation gas tube. The pressure sensing tube may extend from the ventilation gas tube into the nasal occiput to position a pressure sensing port in fluid communication with an annular inflation chamber. The pressure sensing port of the pressure sensing tube may be in fluid communication with the annular inflation chamber through a pressure sensing channel defined by the nasal occiput.

[0007] Another aspect of embodiments of this disclosure is a patient ventilation interface, which may include a nasal pillow body defining a Venturi tube throat open to ambient air and having a nasal pillow portion disposed around the Venturi tube throat to define an inflation chamber within the nasal pillow body and outside the Venturi tube throat. The patient ventilation interface may also include a nozzle arranged to deliver ventilation gas into the Venturi tube throat and a pressure sensing tube having a pressure sensing port positioned in fluid communication with the inflation chamber.

[0008] The inflation chamber may have a crescent-shaped cross-section. The venturi throat may be tapered outwards away from the nozzle. The patient ventilation interface may include a ventilation gas tubing terminating at the nozzle. At least a portion of a pressure sensing tube may be disposed within the ventilation gas tubing. The pressure sensing tube may extend from the ventilation gas tubing into the nasal occipital body to position a pressure sensing port in fluid communication with the inflation chamber. The pressure sensing port of the pressure sensing tube may be in fluid communication with the inflation chamber through a pressure sensing channel defined by the nasal occipital body.

[0009] Any of the aforementioned patient ventilation interfaces may include an inlet element defining a Venturi inlet in fluid communication with the Venturi throat. A nozzle may be arranged to deliver ventilation gas through the Venturi inlet to the Venturi throat. The inlet element may define one or more entrainment openings through which the Venturi throat is open to ambient air. A nozzle may be arranged to deliver ventilation gas through one of the entrainment openings to the Venturi inlet. The Venturi inlet may flare outwards relative to the Venturi throat.

[0010] Another aspect of the embodiments of this disclosure is a non-invasive ventilation system. The non-invasive ventilation system may include any of the above-described patient ventilation interfaces and a pressure sensor fluidly connected to a pressure sensing tube.

[0011] Noninvasive ventilation systems may include a controller programmed to respond to patient airway pressure P sensed by a pressure sensor. sense This controls the delivery of ventilation gas from the nozzle. The controller can be programmed to correct for the sensed patient airway pressure P. sense The expected error in the process. The controller can be programmed to apply the sensed patient airway pressure P. sense Index correction factor P delta To correct for the expected error. Correction factor P delta The nozzle flow rate V' can be further determined by the nozzle. n index.

[0012] Non-invasive ventilation systems may include a non-transitory program storage medium on which instructions are stored. These instructions can be executed by a processor or programmable circuitry to correct the sensed patient airway pressure P. sense The expected error in the process. Instructions can be executed by a processor or programmable circuitry to apply the sensed patient airway pressure P. sense Index correction factor P delta To correct for the expected error. Correction factor P delta The nozzle flow rate V' can be further determined by the nozzle. n index.

[0013] Another aspect of the embodiments of this disclosure is a method for calibrating the sensed patient airway pressure P in a patient ventilation interface. sense The method may include: providing a patient ventilation interface including a laryngeal body defining a venturi larynx open to ambient air, a nasal bolus disposed around the venturi larynx to define an inflation chamber between the venturi larynx and a nasal bolus, and a nozzle arranged to deliver ventilation gas to the venturi larynx; sensing the patient airway pressure P in a pressure sensing tube. sense The pressure sensing tube has a pressure sensing port positioned in fluid communication with the inflation chamber; and applies the sensed patient airway pressure P. sense Index correction factor P delta Correcting the sensed patient airway pressure P sense The expected error in the calculation. Correction factor P delta The nozzle flow rate V' can be further determined by the nozzle. n index.

[0014] The nasal pillow can be a component of the main body of the throat.

[0015] Another aspect of the embodiments of this disclosure is a method of non-invasive ventilation. The method may include: providing a patient ventilation interface including a laryngeal body defining a venturi larynx open to ambient air, a nasal bolus disposed around the venturi larynx to define an inflation chamber between the venturi larynx and a nasal bolus, and a nozzle arranged to deliver ventilation gas to the venturi larynx; and sensing the patient airway pressure P in a pressure sensing tube. sense The pressure sensing tube has a pressure sensing port positioned in fluid communication with the inflation chamber; and a response to the patient airway pressure P sensed by the pressure sensor. sense To control the delivery of ventilation gas output from the nozzle.

[0016] The nasal pillow can be a component of the main body of the throat.

[0017] Another aspect of the embodiments of this disclosure is a method for calibrating the sensed patient airway pressure P in a patient ventilation interface. sense The method may include providing a patient ventilation interface comprising a laryngeal body defining a venturi tube larynx open to ambient air, a nasal bolus disposed around the laryngeal body to define an annular inflation chamber between the laryngeal body and a nasal bolus, and a nozzle arranged to deliver ventilation gas to the venturi tube larynx. The method may also include sensing a patient airway pressure P in a pressure sensing tube. sense The pressure sensing tube has a pressure sensing port positioned in fluid communication with an annular inflation chamber. The method may include applying a pressure sensing port to the annular inflation chamber via a sensed patient airway pressure P. sense Index correction factor P delta To correct the sensed patient airway pressure P sense The expected error in the calculation. Correction factor P delta The nozzle flow rate V' can be further determined by the nozzle. n index.

[0018] Another aspect of the embodiments of this disclosure is a method of non-invasive ventilation. The method may include providing a patient ventilation interface comprising a laryngeal body defining a Venturi tube larynx open to ambient air, a nasal bolus disposed around the laryngeal body to define an annular inflation chamber between the laryngeal body and a nasal bolus, and a nozzle arranged to deliver ventilation gas to the Venturi tube larynx. The method may include sensing a patient airway pressure P in a pressure sensing tube. sense The pressure sensing tube has a pressure sensing port positioned in fluid communication with an annular inflation chamber. The method may include responding to a patient airway pressure P sensed by a pressure sensor. sense To control the delivery of ventilation gas output from the nozzle.

[0019] Another aspect of the embodiments of this disclosure is a method for calibrating the sensed patient airway pressure P in a patient ventilation interface. senseThe method may include providing a patient ventilation interface including a nasal bolus body defining a Venturi tube larynx open to ambient air and having a nasal bolus portion disposed around the larynx to define an inflation chamber within the nasal bolus body and outside the Venturi tube larynx. The patient ventilation interface also includes a nozzle arranged to deliver ventilation gas into the Venturi tube larynx. The method may include: sensing a patient airway pressure P in a pressure sensing tube. sense The pressure sensing tube has a pressure sensing port positioned in fluid communication with the inflation chamber; and applies the sensed patient airway pressure P. sense Index correction factor P delta To correct the sensed patient airway pressure P sense The expected error in the calculation. Correction factor P delta The nozzle flow rate V' can be further determined by the nozzle. n index.

[0020] Another aspect of the embodiments of this disclosure is a method of non-invasive ventilation. The method may include providing a patient ventilation interface including a nasal bolus body defining a Venturi tube larynx open to ambient air and having a nasal bolus portion disposed around the larynx to define an inflation chamber within the nasal bolus body and outside the Venturi tube larynx. The patient ventilation interface also includes a nozzle arranged to deliver ventilation gas into the Venturi tube larynx. The method may include: sensing patient airway pressure in a pressure sensing tube. Psense The pressure sensing tube has a pressure sensing port positioned in fluid communication with the inflation chamber; and a response to the patient airway pressure sensed by the pressure sensor. Psense To control the delivery of ventilation gas output from the nozzle.

[0021] This disclosure will be best understood by referring to the following detailed description when read in conjunction with the accompanying drawings. Attached Figure Description

[0022] 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 the same numerals always refer to the same parts, and wherein:

[0023] Figure 1 This is a perspective view of an exemplary patient ventilation interface according to an embodiment of the present disclosure;

[0024] Figure 2 yes Figure 1 A top view of the patient ventilation interface shown;

[0025] Figure 3 yes Figure 1 The front view of the patient ventilation interface shown;

[0026] Figure 4 yes Figure 3 The patient ventilation interface shown is a cross-sectional front view.

[0027] Figure 5 The illustrations, based on embodiments of this disclosure, relate to other components of a non-invasive ventilation system. Figure 1-4 A three-dimensional cross-sectional view of the patient's ventilation interface;

[0028] Figure 6 Exemplary performance characteristics of the patient ventilation interface are depicted graphically.

[0029] Figure 7 A trend line is shown for the coefficients of the correction factor used to determine the patient airway pressure sensed using the patient ventilation interface;

[0030] Figure 8 This is a cross-sectional front view of another exemplary patient ventilation interface according to an embodiment of the present disclosure;

[0031] Figure 9 This is a perspective view of another exemplary patient ventilation interface according to an embodiment of the present disclosure;

[0032] Figure 10 yes Figure 9 A front view of the patient ventilation interface, showing the vertical bending capability of the spacer integrated therein;

[0033] Figure 10A Depicting Figure 9 An exemplary vertically bent configuration of the patient ventilation interface shown;

[0034] Figure 10B Depicting Figure 9 Another exemplary vertically curved configuration of the patient ventilation interface shown;

[0035] Figure 11 yes Figure 9 A top view of the patient ventilation interface, showing the horizontal bending capability of the spacer;

[0036] Figure 11A Depicting Figure 9 An exemplary horizontal bend configuration of the patient ventilation interface shown;

[0037] Figure 11B Depicting Figure 9 Another exemplary horizontally curved configuration of the patient ventilation interface shown;

[0038] Figure 12 yes Figure 9 A top view of the patient ventilation interface, showing the tensile strength of the spacer;

[0039] Figure 12A Depicting Figure 9An exemplary stretch configuration of the patient ventilation interface shown;

[0040] Figure 13 yes Figure 9 A three-dimensional diagram of the patient ventilation interface, showing the torsional capacity of the spacer;

[0041] Figure 13A Depicting Figure 9 An exemplary torsion configuration of the patient ventilation interface shown;

[0042] Figure 14 yes Figure 9 A top view of the patient ventilation interface, showing the rotational capability of the pair of nasal pillows integrated therein;

[0043] Figure 14A Depicting Figure 9 An exemplary rotating configuration of the patient ventilation interface shown;

[0044] Figure 14B Depicting Figure 9 Another exemplary rotating configuration of the patient ventilation interface shown;

[0045] Figure 15 This is a perspective view of another exemplary patient ventilation interface according to an embodiment of the present disclosure;

[0046] Figure 16 yes Figure 15 A top view of the patient ventilation interface shown; and

[0047] Figure 17 yes Figure 15 The patient ventilation port shown is a cross-sectional front view. Detailed Implementation

[0048] This disclosure includes various embodiments of nasal pillow-type patient ventilation interfaces for non-invasive ventilation systems, as well as systems and methods for accurate pressure measurement using the patient ventilation interface. The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of several currently contemplated embodiments and is not intended to represent the only form that can be developed or utilized with the disclosed interface. The description illustrates functions and features in conjunction with the illustrated embodiments. However, it should be understood that the same or equivalent functionality can be implemented by different embodiments that 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 such entities.

[0049] Figure 1 This is a perspective view of an exemplary patient ventilation interface 100 according to an embodiment of the present disclosure. Figure 2 and Figure 3These are top and side views of the patient airway 100. As shown, the patient airway 100 can be a type of nasal pillow defined by a pair of nasal pillows 110 configured to at least partially insert into the patient's nostrils. The pair of nasal pillows 110 can be respectively configured as a left pillow assembly 102a and a right pillow assembly 102b for the patient airway 100. The left and right pillow assemblies 102a and 102b can be symmetrically constructed and separated by spacers 104 to fit into the patient's left and right nostrils. Each nasal pillow 110 can be made of a flexible material, such as an elastomer, which conforms to the interior of the patient's nostril and forms a seal to prevent leakage between the nasal pillow 110 and the nostril during use. For this purpose, each nasal pillow 110 can be bell-shaped or otherwise tapered outwards for a better fit when inserted deeper into the nostril. Ventilation gas can be delivered to the patient via a pair of jet venturi tubes 120, which are coupled to a corresponding one of the left occipital assembly 102a and the right occipital assembly 102b of the patient ventilation interface 100. Each jet venturi tube 120 includes a venturi throat 122 open to ambient air and one or more nozzles 124 for delivering ventilation gas into the venturi throat 122. In this respect, as in Figure 4 and Figure 5 As most clearly shown in the cross-sectional view, the nasal pillow 110 of each pillow assembly 102a, 102b can be arranged around the laryngeal body 130, which defines the venturi throat 122 of the corresponding jet venturi tube 120. Ventilation gas exiting the venturi throat 122 can enter the patient's nostrils through an opening 112 defined in the corresponding nasal pillow 110 (in some cases, the laryngeal body 130 itself protrudes through the opening 112).

[0050] To provide accurate pressure sensing within the patient airway 100, each nasal pillow 110 may be positioned around a corresponding laryngeal body 130 to define an annular inflation chamber 140 between the laryngeal body 130 and the nasal pillow 110. It has been found that the pressure within the annular inflation chamber 140 approximates the patient's actual airway pressure P. aw This results in consistent, predictable errors. To sense the pressure within the annular inflation chamber 140, the patient ventilation interface 100 may include a pressure sensing tube 150 with a distal pressure sensing port 152 in each pillow assembly 102a, 102b (or in some cases only in one of them), the distal pressure sensing port 152 being positioned in fluid communication with the annular inflation chamber 140. The pressure sensing port 152 of the pressure sensing tube 150 may be located within the annular inflation chamber 140 or may be indirectly in communication with the annular inflation chamber 140, for example through a pressure sensing channel 114 defined by the corresponding nasal pillow 110, such as... Figure 4 and Figure 5As shown. Preferably, the pressure sensing port 152 is located outside the annular inflation chamber 140, using the pressure sensing channel 114 as the communication medium, or exactly within the annular inflation chamber 140 at or near its base (and thus at or near the base of the nasal occipital 110), because it has been found that the further into the annular inflation chamber 140 (i.e., the closer to the patient) the measurement is performed, the greater the turbulence, making accurate measurement more difficult. By providing the annular inflation chamber 140 and using the pressure sensing port 152 of the pressure sensing tube 150 oriented as described above to sense the patient's airway pressure therein, the patient ventilation interface 100 avoids the difficulty of accurately sensing the pressure within the jet venturi tube 120 itself, where gas velocity and hydrodynamics are at their maximum. Meanwhile, the sensing line does not necessarily need to protrude beyond the nasal occipital 110 and enter the patient's nostril, which could be uncomfortable and unpleasant for the patient, and in any case, it is not necessarily guaranteed that the sensing location is in a low-speed region.

[0051] Each pillow assembly 102a, 102b may further include an inlet 160 defining a Venturi inlet 126 in fluid communication with the Venturi throat 122 of a corresponding jet Venturi tube 120. A nozzle 124 may be arranged to deliver ventilation gas through the Venturi inlet 126 to the Venturi throat 122. Figure 5 As best understood, the inlet 160 may include a generally truncated conical portion that defines an outward flare of the Venturi inlet 126 relative to the Venturi throat 122, which is open to ambient air through one or more entrainment openings 128 in the inlet 160. Because the Venturi inlet 126 flares outward relative to the Venturi throat 122, the Venturi throat 122 constricts the flow of ventilation gas. Due to the increased velocity of the ventilation gas at the constriction, the pressure of the ambient air entrained through the one or more entrainment openings 128 decreases. By amplifying the ventilation gas output from the nozzle 124 in this way, the jet Venturi 120 can be used as an effective flow generator when providing ventilation therapy to a patient. Simultaneously, the one or more entrainment openings 128 can additionally serve as an exhalation port for the patient to exhale during ventilation therapy.

[0052] In the illustrated example, the jet venturi 120 of each pillow assembly 102a, 102b defines a single entrainment opening 128, which has a generally annular profile and spans almost the entire 360°. A corresponding nozzle 124 is arranged to deliver ventilation gas through the entrainment opening 128 to the venturi inlet 126, such that ambient air drawn into the entrainment opening 128 flows around the periphery of the nozzle 110. With this arrangement, the nozzle 124 can be positioned outside the entrainment opening 128 as shown, or it can protrude through the entrainment opening 128 into the venturi inlet 126 to be located downstream of the entrainment opening 128. In addition to or instead of this arrangement, it is also contemplated that one or more entrainment openings 128 can be formed in the sidewall of the inlet member 160, such that ambient air drawn into the entrainment opening 128 flows in a parallel or adjacent relationship to the ventilation gas delivered by the nozzle 124.

[0053] Ventilation gas can be supplied to the patient ventilation interface 100 via a pair of ventilation gas tubing 170, each ventilation gas tubing 170 terminating at a corresponding nozzle 124 (or terminating at a plurality of corresponding nozzles 124 in the case where each jet venturi tubing 120 has more than one nozzle 124). This can be achieved, for example, via a ventilator 200 (see...). Figure 5 The ventilation gas source is used to provide ventilation gas. Exemplary ventilators and associated oxygen concentrators that can be used with the disclosed embodiments include those described in the following documents: U.S. Patent No. 9,132,250, entitled "Methods, Systems, and Apparatus for Noninvasive Ventilation, including an unsealed ventilation interface with a clamp port and / or pressure characteristics"; U.S. Patent No. 9,675,774, entitled "Methods, Systems, and Apparatus for Noninvasive Open Ventilation Using a Gas Delivery Nozzle in Free Space"; U.S. Patent No. 9,962,512, entitled "Methods, Systems, and Apparatus for Noninvasive Open Ventilation Using a Gas Delivery Nozzle in Free Space"; Methods, systems, and apparatuses for supplying gas, including unsealed venting interfaces featuring free-space nozzles; 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 “Oxygen Concentrator with Screen Bed Bypass and Method for Controlling the Same Thereof”, the entire contents of each of these documents are expressly incorporated herein by reference.

[0054] To minimize the number of exposed tubes, at least a portion of each pressure-sensing tube 150 may be disposed within a corresponding ventilation gas tube 170. Each pressure-sensing tube 150 can then branch off from the corresponding ventilation gas tube 170 to be guided to the annular inflation chamber 140 and / or pressure-sensing channel 114 of the associated nasal pillow 110. For this purpose, each ventilation gas tube 170 may have an opening 172 in its sidewall at a location prior to the termination of the ventilation gas tube 170 at the corresponding nozzle 124, and the associated pressure-sensing tube 150 may extend through the opening 172 to extend from the ventilation gas tube 170 into or toward the nasal pillow 110. To arrange the pressure-sensing tubes 150 from the ventilation gas tube 170 to the annular inflation chamber 140 or pressure-sensing channel 114, each pillow assembly 102a, 102b may also include a sheath 180. Figure 5 As shown, the sheath 180 of each pillow assembly 102a, 102b connects the opening 172 in the sidewall of the corresponding ventilation gas tube 170 to the associated nose pillow 110, and thus interrupts the truncated conical portion of the inlet 160 at a location along its periphery. This is why, as described above, the clamping opening 128 can span almost, but not completely, 360°. The sheath 180 can also be used to attach the ventilation gas tube 170 to the remainder of the corresponding pillow assembly 102a, 102b.

[0055] like Figure 5 As schematically shown, the delivery of ventilation gas to nozzles 124 of pillow assemblies 102a, 102b can be facilitated by several portions of a multi-lumen conduit 300, each portion of which defines at least a ventilation gas lumen 310 and a pressure sensing lumen 320. In an exemplary system architecture, two separate portions of the multi-lumen conduit 300 are fluidly connected to a patient ventilation interface 100, such that the ventilation gas lumen 310 defined thereunder is in fluid communication with a corresponding ventilation gas tube 170, while the pressure sensing lumen 320 is in fluid communication with a corresponding pressure sensing tube 150 located within the corresponding ventilation gas tube 170. As an alternative to the exemplary ventilation gas tube 170 housing the pressure sensing tube 150 as shown, it is conceivable that the ventilation gas tube 170 itself may be a multi-lumen tube that can be connected to or integrated with a corresponding portion of the multi-lumen conduit 300 and includes separate lumens for delivering ventilation gas and sensing pressure, the latter terminating at an opening 172. In this case, the pressure sensing tube 150 can simply extend from the opening 172 of the ventilation gas tube 170 to the corresponding annular inflation chamber 140 or pressure sensing channel 114 of the nasal pillow 110, without being located in the ventilation gas tube 170 at all.

[0056] To determine the patient's airway pressure, the system 10, including the patient ventilation interface 100, may also include a pressure sensor 210 fluidly connected to the pressure sensing tube 150 of the patient ventilation interface 100. Figure 5 In the exemplary noninvasive ventilation system 10 shown, for example as described above, a pressure sensor 210 is located within the ventilator 200. The pressure sensor 210 can sense the pressure P in the annular inflation chamber 140 at the location of the pressure sensing port 152 of the pressure sensing tube 150. sense Pressure P can be sensed either directly or indirectly through a pressure sensing channel 114 formed in the nasal pillow 110. sense This can be referred to as the sensed patient airway pressure P. sense And it can approximate the actual patient airway pressure P in the patient's airway. aw For example, the patient airway pressure P is sensed based on the movement of the diaphragm within the pressure sensor 210. sense This can be detected by the pressure sensor 210 located above the pressure sensing lumen 320 of the aforementioned portion of the pressure sensing tube 150 and the multi-lumen conduit 300. Along these lines, in Figure 5 In the exemplary system architecture schematically illustrated, it is envisioned that the fluid connection of the multi-lumen conduit 300 to two separate portions of the patient ventilation interface 100, as described above, is also fluidly connected to corresponding branches of a Y-connector, the remaining branches of which are fluidly connected to the ventilator 200 via a third separate portion of the multi-lumen conduit 300. A pressure-sensing lumen 320 defined by this third portion of the multi-lumen conduit 300 is fluidly connected to a pressure sensor 210 of the ventilator 200. As will be appreciated, integrating the Y-connector into the exemplary system architecture effectively branches the pressure-sensing lumen 320, which extends directly to the pressure sensor 210, into a pair of pressure-sensing lumens 320 defined by corresponding portions of each of the two remaining portions of the multi-lumen conduit 300 that extend directly to the patient ventilation interface 100. In a similar manner, the Y-connector effectively branches the ventilation gas lumen 310, which extends directly to the ventilator 200, into a pair of ventilation gas lumens 310, which are defined by corresponding portions of each of the two remaining portions of the multi-lumen conduit 300 that extend directly to the patient ventilation interface 100, thereby providing a ventilation gas flow path from the ventilator 200 to the nozzle 124 of each jet venturi tube 120.

[0057] like Figure 5 As further shown, system 10 may additionally include controller 220, which is programmed to respond to patient airway pressure P sensed by pressure sensor 210. sense This controls the delivery of ventilation gas output from nozzle 124. The sensed patient airway pressure P...sense This can be used for pressure triggering, for example, where controller 220 can deliver a wisp of ventilation gas at a specific phase of the patient's breathing (typically during inspiration), or to provide positive end-expiratory pressure (PEEP) during the expiratory phase. The controlled delivery of ventilation gas can be performed according to a pre-set time-based schedule. As described above, the patient airway pressure P sensed within the annular inflation chamber 140... sense Approximate the patient's actual airway pressure P with a consistent, predictable error. aw The controller 220 can be programmed to correct for expected errors, for example, by applying the sensed patient airway pressure P. sense Index correction factor P delta The actual patient airway pressure P aw It can be approximated as P aw =P sense +P delta .

[0058] Figure 6 The nozzle flow rate V', representing the total airflow of the ventilation gas output from nozzle 124, is depicted graphically. n Exemplary performance characteristics of the patient ventilation interface 100 under various settings. For each nozzle flow rate V' n (10.00 slpm, 20.00 slpm, 30.00 slpm, and 40.00 slpm), showing different patient airway flow rates V' aw The value (which can be simulated, for example, using a variable resistor) is related to the actual patient airway pressure P. aw Comparison of sensed patient airway pressure P sense On the same graph, the actual patient airway pressure P aw and the sensed patient airway pressure P sense The difference between them is plotted as P delta This indicates the patient airway pressure P used for calibration. sense The correction factor is shown in Table 1 below.

[0059] Table 1

[0060]

[0061] right Figure 6 All V' aw -P aw V' aw -P sense and V' aw -P delta Regression analysis of the curve produces a linear trend line with a high coefficient of determination (e.g., R-squared > 0.99). In principle, V' aw -Pdelta The curve can be summarized by the following equation 1-4, where m 40 m 30 m 20 and m 10 b is the slope of the linear trend line. 40 b 30 b 20 and b 10 The flow rate V' for each corresponding nozzle was determined from regression analysis. n The y-intercept of the linear trend line at:

[0062] P delta =m 40 V′ aw +b 40 When V′ n =40slpm (Equation 1)

[0063] P delta =m 30 V′ aw +b 30 When V′ n =30slpm (Equation 2)

[0064] P delta =m 20 V′ aw +b 20 When V′ n =20slpm (Equation 3)

[0065] P delta =m 10 V′ aw +b 10 When V′ n =10slpm (Equation 4).

[0066] Compensate P using the above equation. sense That is, for any V' aw P aw Approximately P aw =P sense +P delta This produces an approximate P within the measurement accuracy requirement of ±(2cmH2O+4%). aw .

[0067] However, in practice, V' n It can vary arbitrarily within a certain range, and V' aw It can be unknown. Therefore, in the case of the non-invasive ventilation system 10, the controller 220 can determine any V'. n and unknown V' aw Correction factor Pdelta To demonstrate this, the remaining linear trend lines can be summarized as shown in Table 2 below:

[0068] Table 2

[0069] <![CDATA[V’ n ]]> <![CDATA[V’ aw -P aw ]]> <![CDATA[V’ aw -P sense ]]> <![CDATA[V’ aw -P delta (Equations 1-4) 40slpm <![CDATA[P aw =m a40 V′ aw +b a40 ]]> <![CDATA[P sense =m s40 V′ aw +b s40 ]]> <![CDATA[P delta =m 40 V′ aw +b 40 ]]> 30slpm <![CDATA[P aw =m a30 V′ aw +b a30 ]]> <![CDATA[P sense =m s30 V′ aw +b s30 ]]> <![CDATA[P delta =m 30 V′ aw +b 30 ]]> 20slpm <![CDATA[P aw =m a20 V′ aw +b a20 ]]> <![CDATA[P sense =m s20 V′ aw +b s20 ]]> <![CDATA[P delta =m 20 V′ aw +b 20 ]]> 10slpm <![CDATA[P aw =m a10 V′ aw +b a10 ]]> <![CDATA[P sense =m s10 V′ aw +b s10 ]]> <![CDATA[P delta =m 10 y′ aw +b 10 ]]>

[0070] Since the common variable is V' aw You can use V' aw -P sense and V' aw -P delta The trend line will P delta Represented as P sense The function. That is, in V' n =40 slpm, can

[0071] P sense =m s40 V′ aw +b s40

[0072] Rearrange to obtain

[0073]

[0074] It can be substituted into Equation 1 to obtain

[0075]

[0076] It can be simplified to the following linear equation:

[0077]

[0078] Apply the same method to each V' n The value of P delta Rewritten as P sense The function produces four linear functions, listed in Table 3 below:

[0079] Table 3

[0080]

[0081] like Figure 7 As shown, the coefficient A can then be plotted. 40 A 30 A 20 and A 10 and coefficient B 40 B 30 B 20 and B 10 The graph is used to determine the nozzle flow rate V' through regression analysis.n Trend lines for the coefficients A and B of the function:

[0082]

[0083]

[0084] These two polynomial equations (from the pair) Figure 7 The regression analysis performed on the data revealed its coefficient α. A a B b A b B c A and c B ) can be used for any arbitrary V' n Generate coefficients A and B, which can then be used to evaluate P. sense P of the function delta The general equation is:

[0085] P delta =AP sense +B (Equation 7)

[0086] Using Equation 7, any sensed patient airway pressure P can be calculated. sense Correction factor P delta Finally, it can be based on P aw =P sense +P delta By measuring the patient's airway pressure P sense With the calculated correction factor P delta Adding them together approximates the actual patient airway pressure P. aw Because, as described above, the patient's airway pressure P is sensed in the annular inflation chamber 140. sense The fluid dynamics are reduced relative to the space within each jet venturi tube 120 itself, so the resulting approximate patient airway pressure P aw The measurement accuracy will be within ±(2cmH2O+4%).

[0087] As mentioned above, this is used to determine the correction factor P. delta As demonstrated by the exemplary process, the controller 220 of system 10 can be programmed to apply a correction factor P. delta To correct the sensed pressure P sense The expected error in the calculation, the correction factor can typically be P. delta =f(V' n ,P sense A second-order polynomial of the form ). Correction factor P delta The patient's airway pressure P can be sensed sense(For example, according to Equation 7) index, and can further be determined by the nozzle flow rate V' of nozzle 124. n Index (e.g., according to Equations 5 and 6). Additionally, controller 220 can perform calculations and / or refer to a pre-calculated lookup table to determine the index at input P. sense and / or V' n Correction factor P under the condition delta Any combination of such methods falls into the category of P sense and / or V' n For the correction factor P delta The meaning of indexing.

[0088] Figure 8 This is a cross-sectional front view of another exemplary patient ventilation interface 800 according to an embodiment of the present disclosure. The patient ventilation interface 800 can also be integrated into system 10, for example... Figure 5 The exemplary noninvasive ventilation system 10 shown includes a ventilator 200 and a multi-lumen tubing 300. However, compared to the patient ventilation interface 100, in addition to the first pressure sensing tube 150, the patient ventilation interface 800 may also incorporate a second pressure sensing tube 850 in one of the left occipital assembly 102a and the right occipital assembly 102b for sensing the inlet pressure of the corresponding jet venturi tube 120. For example, the pressure sensing port 852 of the second pressure sensing tube 850 may be positioned in fluid communication with a negative pressure region of the jet venturi tube 120, such as within the venturi tube inlet 126 or just within the venturi tube throat 122 and outside the cone of ventilation gas output from the associated nozzle 124.

[0089] One of the ventilation tubes 170 that replaces the patient ventilation interface 100. Figure 8 The patient ventilation port 800 may have a ventilation gas tube 870. The ventilation gas tube 870 may be identical to the ventilation gas tube 170, except that it further includes a second opening 872 in its sidewall. Similar to the first pressure sensing tube 150, at least a portion of the second pressure sensing tube 850 may be disposed within the ventilation gas tube 870. The second pressure sensing tube 850 can then branch from the ventilation gas tube 870 to be guided through a corresponding inlet 160 to the venturi throat 122. For this purpose, the second opening 872 in the sidewall of the ventilation gas tube 870 may be located after the first opening 172 but before the ventilation gas tube 870 terminates at the nozzle 124, through which the second pressure sensing tube 850 may pass. The second pressure sensing tube 850 may be fixed to the outer wall of a corresponding sheath 180 as shown, or may be within a similar sheath extending within the venturi inlet 126.

[0090] By combining the second pressure sensing tube 850, the sensed patient airway pressure P in the corresponding annular inflation chamber 140 can be obtained.sense (or an approximate actual patient airway pressure P) aw =P sense +P delta ) and the throat inlet pressure P sensed by the second pressure sensing tube 850 in The pressure difference between them. This pressure difference can be used to calculate the airflow through the larynx 122 of the venturi tube, and thus approximate the patient's airflow V' when both inhaled and exhaled airflows are present. aw For example, the approximate patient airflow V' aw It can be used to further reduce the approximate patient airway pressure P aw Errors and / or flow triggering for ventilator 200.

[0091] As will be appreciated, integrating the patient ventilation interface 800 into the system 10 will require a portion of the multi-lumen conduit 300 extending to the ventilation gas tubing 870 of the patient ventilation interface 800 (and its ventilation gas lumen 310 and pressure sensing lumen 320 being fluidly connected to the respective ventilation gas tubing 870 and pressure sensing tubing 150) to define a dedicated second pressure sensing lumen in addition to the pressure sensing lumen 320. This second pressure sensing lumen will be positioned in fluid communication with the pressure sensing tubing 850 using a Y-connector, and will also be positioned in fluid communication with a corresponding second pressure sensing lumen, which is further defined by a portion of the multi-lumen conduit 300 extending between the Y-connector and the ventilator 200. The sensed pressure provided to the ventilator 200 by the second pressure sensing lumen through these two portions of the multi-lumen conduit 300 will be sensed by the pressure sensor 210 independently of the sensed pressure provided through the pressure sensing lumen 320, thereby allowing the calculation of the aforementioned pressure difference. While it is envisioned that the patient ventilation interface 800 will be equipped with only one pressure sensing tube 850, those skilled in the art will recognize that the patient ventilation interface 800 can be combined with a pair of second pressure sensing tubes 850 (and associated ventilation gas tubes 870) in one of the corresponding units of the left occipital assembly 102a and the right occipital assembly 102b. In this case, the system 10 will require two portions of the multi-lumen conduit 300 extending to the corresponding ventilation gas tube 870 to each further define a dedicated second pressure sensing lumen in addition to the pressure sensing lumen 320. These second pressure sensing lumens will be positioned to be in fluid communication with the corresponding pressure sensing tube 850 using a Y-connector, and will also be positioned to be in fluid communication with a corresponding second pressure sensing lumen further defined by a portion of the multi-lumen conduit 300 extending between the Y-connector and the ventilator 200.

[0092] Figure 9 This is a perspective view of another exemplary patient ventilation interface 900 according to an embodiment of the present disclosure. The patient ventilation interface 900 can also be integrated into system 10, for example... Figure 5 The exemplary non-invasive ventilation system 10 shown includes a ventilator 200 and a multi-lumen tubing 300. The patient ventilation interface 900 illustrates an alternative shape factor including several additional features, any one or all of which can be incorporated into the aforementioned patient ventilation interfaces 100, 800. For example, while the patient ventilation interface 900 includes a pair of nasal pillows 910 respectively provided for the left occipital assembly 902a and the right occipital assembly 902b, they can functionally... Figures 1-5 and Figure 8 The left occipital assembly 102a and the right occipital assembly 102b shown have identical nasal pillows 110, with the nasal pillow 910 depicted as having an elliptical rather than circular cross-section. Therefore, the nasal pillow 910 can better adapt to the anatomical shape of the patient's nostrils for a more comfortable fit and better seal. To further improve fit and address anatomical differences between patients, it is envisioned that the nasal pillows 910 could be configured to rotate around their respective defining Venturi larynx 922 and laryngeal body 930 (functionally corresponding to the laryngeal body 130 of the patient airway interfaces 100, 800).

[0093] Besides serving as an axis when rotating the nasal pillow 910, a further difference between each laryngeal body 930 and the previously depicted laryngeal body 130 is that the outer surface of the laryngeal body 930 is splined. By providing the laryngeal body 930 with splines in this way, it can be ensured that the annular air chamber 940 (corresponding to the annular air chamber 140) defined between the laryngeal body 930 and the nasal pillow 910 does not become closed or collapse, which could negatively affect the sensed patient airway pressure P. sense The accuracy of the sensing tube 950 is thus ensured. Therefore, the spline design makes the sensing tube 950 insensitive to the occlusion of the nasal bolus 910 and the throat body 930. More specifically, according to its splined construction, a series of elongated, vertically extending channels or grooves are formed around the outer surface of the throat body 930, equidistant from each other, each reaching a predetermined depth, which can be uniform or variable along its length. Similarly, the circumferential width of each channel can be uniform or variable along its length. Figure 9 As shown, while the channel will preferably extend to the distal end of the laryngeal body 930, it is envisioned that the opposite end may terminate slightly above the base of the corresponding annular air chamber 940. Since the laryngeal body 930 may have greater rigidity than the nasal pillow 910 (which is preferably softer for increased patient comfort), the relatively less rigid nasal pillow 910 may have a greater tendency to elastically deflect or deform to directly contact the outer surface of the laryngeal body 930 (particularly in the distal region entering the nostril), thereby potentially completely or partially obstructing fluid communication to the corresponding pressure sensing tubes 150, 850 at the base of the associated annular air chamber 940. As described above, the inclusion of the channel effectively prevents any such obstruction.

[0094] Figure 9 The housing 990 of each pillow assembly 902a, 902b is also depicted, which can be used to conceal the shape of functional components (e.g., inlet 160) and form the desired shape factor for easy patient operation. In the example shown, the two housings 990 are connected by a spacer 904, which can be functionally identical to the spacer 104 described above. Within the housing 990, the venturi throat 922 can be fluidly connected to the corresponding ventilation gas tube 970 (corresponding to ventilation gas tube 170), and the annular inflation chamber 940 is fluidly connected to the corresponding pressure sensing tube 950 (corresponding to pressure sensing tube 150).

[0095] Figure 10 This is a front view of the patient ventilation interface 900, showing the vertical bending capability of the spacer 904. The spacer 904 can be made of or include a material that can be manually deformed and retains its new shape during deformation, such as a metal wire (e.g., aluminum) or a shape memory polymer (e.g., a polymer that only returns to its relaxed state when a specific stimulus is applied (e.g., heated to a specific temperature or exposed to specific light)). Therefore, the spacer 904 can have degrees of freedom of movement in three dimensions, enabling various adjustments to the patient ventilation interface 900 to accommodate diverse patient anatomy and preferences, including… Figure 10 The vertical bend shown in the diagram. Figure 10A An exemplary vertically curved configuration of the patient ventilation interface 900 is shown, wherein the spacer 904 has been bent upward at its end to bring the nasal pillow 910 inward so that they face each other and are closer together. Figure 10B Another exemplary vertically curved configuration of the patient ventilation interface 900 is shown, in which the spacer 904 has been bent downward at its end to move the nasal pillow 910 outward, so that they are opposite to each other and further apart.

[0096] Figure 11 This is a top view of the patient ventilation interface 900, showing the horizontal bending capability of the spacer 904. Figure 11A An exemplary horizontally curved configuration of the patient ventilation interface 900 is shown, wherein the spacer 904 has been bent outward (away from the patient) at its end to rotate the entire left occipital assembly 902a and right occipital assembly 902b outward. Figure 11B Another exemplary horizontally bent configuration of the patient ventilation interface 900 is shown, wherein the spacer 904 has been bent inward (towards the patient) at its end to rotate the entire left occipital assembly 902a and right occipital assembly 902b inward. This horizontal bending capability of the spacer 904 can be as follows: Figure 11This is more easily achieved by including a pre-formed U-shaped or V-shaped bend 905 at the midpoint between the left occipital assembly 902a and the right occipital assembly 902b in the spacer 904. The spacer 904 can be effectively bent outward or inward, respectively, when the pre-formed bend 905 is manually widened (opened) or narrowed (closed).

[0097] Figure 12 This is a top view of the patient ventilation interface 900, showing the stretchability of the spacer 904. By manually pulling apart the left occipital assembly 902a and the right occipital assembly 902b to retract the pre-formed bend 905, the patient can effectively stretch or lengthen the spacer 904, allowing the nasal pillows 910 to be further apart (e.g., to match the distance between the patient's nostrils). Figure 12A An exemplary stretched configuration of the patient ventilation interface 900 is shown, wherein the spacer 904 has been stretched to its maximum length and thus completely removed the pre-formed bend 905, thereby positioning the nasal pillows 910 at their maximum distance from each other. By pushing the left occipital assembly 902a and the right occipital assembly 902b towards each other again, the pre-formed bend 905 can be reshaped to accommodate the adjustment as the spacer 904 bends again.

[0098] Figure 13 yes Figure 9 A three-dimensional view of the patient ventilation interface 900, showing the torsional capacity of the spacer 904. Figure 13A An exemplary torsional configuration of the patient ventilation interface 900 is shown. It can be seen that the spacer 904 allows the patient ventilation interface 900 to deform freely in various ways, such as oriented one of the pillow assemblies 902a and 902b inwards and the other outwards, as shown. By allowing the patient to freely adjust the orientation of each nasal pillow 910 in three dimensions in this way, the spacer 904 can support the compatibility of the patient ventilation interface 900 with a variety of patient anatomy and preferences, thereby enhancing comfort and fit (and therefore patient compliance).

[0099] Figure 14 yes Figure 9 A top view of the patient ventilation interface 900 shows the rotational capability of the nasal pillows 910. As described above, it is envisioned that the nasal pillows 910 can be configured to rotate around their respective laryngeal bodies 930. Figure 14 This rotational or rotatable capability of the nose pillow 910 relative to the rest of the corresponding pillow assemblies 902a, 902b is shown. Figure 14A An exemplary rotating configuration of the patient ventilation interface 900 is shown, wherein the nasal pillows 910 have been rotated in opposite directions, with the nasal pillow 910 aligned with the patient's left nostril rotating clockwise and the nasal pillow 910 aligned with the patient's right nostril rotating counterclockwise. Figure 14BAnother exemplary rotating configuration of the patient ventilation interface 900 is shown, wherein the nasal pillow 910 is already connected to... Figure 14A The rotation settings are reversed. This time, the nasal pillow 910 aligned with the patient's left nostril has rotated counterclockwise, and the nasal pillow 910 aligned with the patient's right nostril has rotated clockwise. The nasal pillows 910 can also rotate in the same direction as each other, rather than in opposite directions. With its non-circular (e.g., elliptical) rotatable nasal pillow 910, the patient airway 900 can be comfortably inserted into a wide variety of nasal anatomy structures.

[0100] As described above, the nasal pillow 110 can be made of a flexible material, such as an elastomer, which conforms to the interior of the patient's nostril and forms a seal to prevent leakage between the nasal pillow 110 and the nostril during use. In this regard, for example, the nasal pillows 110, 910 can be made of thermoplastic elastomers (TPE) or thermosetting materials produced by liquid injection molding (LIM) using liquid silicone rubber (LSR). Other structures of the patient ventilation interfaces 100, 800, 900, such as the laryngeal bodies 130, 930, inlet piece 160, ventilation tubes 170, 870, 970, sheath 180, and housing 990, can be assembled from one or more components that can be attached to each other, for example, by ultrasonic welding. These structures can be similarly made of thermoplastic or thermosetting materials and generally (though not necessarily) have greater rigidity than the nasal pillows 110, 910 (which can be specifically designed to conform to the patient's nostrils).

[0101] The controller 220 of system 10 (which may be the controller of ventilator 200 as described above) can be implemented using a programmable integrated circuit device such as a microcontroller or control processor. Broadly speaking, the device can receive certain inputs and, based on these inputs, can generate certain outputs. 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 for permanent storage and retrieval of program instructions, and there may also be an internal random access memory (RAM). Computer programs for implementing any of the disclosed functions of controller 220 can reside on such a non-transitory program storage medium, as well as on a removable non-transitory program storage medium such as semiconductor memory (e.g., an IC card), for example, in the case of providing updates to existing equipment. In addition to processor-executable code, examples of program instructions stored on the program storage medium or computer-readable medium may also include status information for execution by programmable circuitry such as a field-programmable gate array (FPGA) or programmable logic device (PLD).

[0102] Figure 15 This is a perspective view of another exemplary patient ventilation interface 1500 according to an embodiment of the present disclosure. Figure 16 and Figure 17 These are a top view and a cross-sectional side view of the patient ventilation interface 1500. The patient ventilation interface 1500 can also be integrated into system 10, for example... Figure 5 The exemplary non-invasive ventilation system 10 shown, including a ventilator 200 and a multi-lumen tubing 300, exhibits an alternative shape factor, except for the patient ventilation interface 1500, which includes several additional features, any or all of which can be incorporated into the aforementioned patient ventilation interfaces 100, 800, and 900. For example, while each of the patient ventilation interfaces 100, 800, and 900 has a pair of nasal pillows 110 and 910 disposed around a laryngeal body 130 and 930 defining a venturi throat 122 and 922, the patient ventilation interface 1500 can be modified to have a pair of nasal pillow bodies 1530, each nasal pillow body 1530 incorporating a nasal pillow portion 1510 as part of it. In particular, the component defining the venturi throat 1522 of the patient ventilation interface 1500 can be combined with a component inserted into the patient's nostril to form a single nasal pillow body 1530. It should be noted that in some cases, the nasal pillow body 1530 can still be referred to as the larynx body, and its nasal pillow portion 1510 is simply called the nasal pillow, even though it can be formed as a component of this larynx body.

[0103] As shown in the figure, each nasal pillow body 1530 may define a venturi throat 1522 of a corresponding jet venturi tube 1520, the venturi throat 1522 being open to ambient air. Each nasal pillow body 1530 may have a nasal pillow portion 1510 disposed around the venturi throat 1522 to define an inflation chamber 1540 within the nasal pillow body 1530 and outside the venturi throat 1522. At least the nasal pillow portion 1510 of each nasal pillow body 1530 may be made of the same material described above with respect to nasal pillows 110, 910. Two such nasal pillow bodies 1530 may be provided for the left occipital assembly 1502a and the right occipital assembly 1502b, respectively, and their functions may be compatible with... Figures 1-5 and Figure 8 The left occipital assembly 102a and the right occipital assembly 102b shown have the same nasal pillow 110. The left occipital assembly 1502a and the right occipital assembly 1502b can be separated, for example, by a spacer 1504 that is identical to spacer 104 or spacer 904. Similar to... Figure 9The nasal pillow 910, nasal pillow body 1530, and especially its nasal pillow portion 1510, may have an elliptical rather than circular cross-section to better adapt to the anatomical shape of the patient's nostrils for a more comfortable fit and better seal. Of particular note is that the air chamber 1540, defined within the nasal pillow body 1530 and outside the venturi throat 1522, can advantageously have, as... Figure 15 and Figure 16 The crescent-shaped cross-section is shown. Compared to the annular air chambers 140 and 940 as described above (see, for example, Figure 1 , Figure 2 and Figure 9 The crescent-shaped cross-section of the air chambers 1540 allows them to enter the nasal occipital body 1530 of the patient's nose, which has a smaller cross-section (because the crescent-shaped air chambers 1540 only need to protrude on one side of the nasal occipital body 1530, thus allowing the nasal occipital body 1530 elsewhere to be only as large as required to define the venturi throat 1522). Furthermore, the construction of the nasal occipital portion 1510 (fitted into the nostril), which is an integrally molded part of the nasal occipital body 1530 (which defines the venturi throat 1522), can use less material and simplifies manufacturing by allowing them to be manufactured in a single molding process without subsequent assembly.

[0104] To sense the pressure within the crescent-shaped inflation chamber 1540, the patient ventilation interface 1500 may include a pressure sensing tube 1550 with a distal pressure sensing port 1552 in each pillow assembly 1502a, 1502b (or in some cases only one of them), the distal pressure sensing port 1552 being positioned in fluid communication with the crescent-shaped inflation chamber 1540, just as the pressure sensing port 152 of the pressure sensing tube 150 described with respect to the patient ventilation interface 100. A portion of the pressure sensing tube 1550 may similarly be disposed within a corresponding ventilation gas tube 1570 terminating at the nozzle 1524 and may be identical to the ventilation gas tubes 170, 870, 970 described above. For example, the pressure sensing tube may extend from the ventilation gas tube 1570 into the nasal pillow body 1530 to position the pressure sensing port 1522 in fluid communication with the inflation chamber 1540 (which may be via a pressure sensing channel defined by the nasal pillow body 1530, which may be identical, for example, to pressure sensing channel 114).

[0105] like Figure 17As best shown, the venturi throat 1522 can be tapered outwards away from the nozzle 1524, thus maximizing its position at the deepest point where it enters the patient's nostril. In this respect, the nasal pillow body 1530 can be shaped to have a gradually increasing inner diameter defining the venturi throat 1522. In the illustrated embodiment, as an example, the nasal pillow body 1530 is assembled with an open inlet 1560 defining the venturi inlet 1526 of the jet venturi 1520. The open inlet 1560 meets the nasal pillow body 1530 at the proximal end of the venturi throat 1522 (i.e., closest to the nozzle 1524 and furthest from the patient), and the nasal pillow body 1530 is fitted over and around the closed, straight portion 1562 of the inlet 1560. Using this structure, the nasal bolster body 1530 can define the diameter d of the venturi throat 1522 at its proximal end, which is equal to or nearly equal to the diameter of the unopened portion 1562 of the inlet member 1560. The diameter of the venturi throat 1522 can then be increased by an opening angle α (see...). Figure 17 The angle α can be defined, for example, between the axis of the Venturi throat 1522 and the inner wall of the nasal occipital body 1530. The angle α can be between 0.5 and 30 degrees, preferably between 1 and 10 degrees. By making the Venturi throat 1522 conical in this way, the performance of the Venturi throat 1522 can be improved because the expanded throat can recover energy better than a cylindrical throat. Furthermore, manufacturability can be improved because conventional molding processes may require draft angles (e.g., at least 1.5 or 2 degrees), making a truly cylindrical throat more difficult (and therefore more expensive) to produce. It should be noted that the outwardly conical Venturi throat 1522 may be particularly practical because the aforementioned crescent-shaped inflation chamber 1540 results in a smaller overall cross-section of the nasal occipital body 1530. Therefore, the feasibility (and the advantages thereof) of the outwardly conical venturi throat 1522 can be considered another advantage of the integrated structure associated with the aforementioned crescent-shaped air chamber 1540 and / or nasal pillow body 1530.

[0106] In the patient ventilation interfaces 100, 800, and 1500 described herein, nozzles 124 and 1524 are shown coaxial with the venturi throats 122 and 1522 (and patient ventilation interface 900 may have a similar arrangement). It has been found that this coaxial arrangement achieves maximum performance. However, this disclosure is not intended to be limited thereto. For example, nozzles 124 and 1524 may be deviated from their coaxiality with the venturi throats 122 and 1522. Introducing such a deviation can advantageously reduce the noise of patient ventilation interfaces 100, 800, 900, and 1500, although it may also result in a slight decrease in performance.

[0107] The above description is given by way of example and is not restrictive. In view of the foregoing disclosure, those skilled in the art can devise variations within the scope and spirit of the invention disclosed herein. Furthermore, the 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 patient ventilation interface, comprising: The main body of the throat, which defines the venturi throat open to ambient air; A nasal pillow is provided around the throat of the venturi tube to define an annular or crescent-shaped air chamber between the throat of the venturi tube and the nasal pillow; The nozzle is arranged to output ventilation gas to the throat of the venturi tube; as well as A pressure sensing tube has a pressure sensing port positioned in fluid communication with the inflation chamber, the pressure sensing port of the pressure sensing tube being located inside the inflation chamber, or indirectly communicating with the inflation chamber through a pressure sensing channel defined by a nose pillow.

2. The patient ventilation interface according to claim 1, characterized in that, The nasal pillow is a component of the main body of the throat.

3. The patient ventilation interface according to claim 1, characterized in that, The main body of the throat has greater rigidity than the nasal pillow.

4. The patient ventilation interface according to claim 1, characterized in that, The outer surface of the main body of the throat has splines.

5. The patient ventilation interface according to claim 1, characterized in that, The inflation chamber has a crescent-shaped cross-section.

6. The patient ventilation interface according to claim 1, characterized in that, The throat of the venturi tube is tapered outwards from the nozzle.

7. The patient ventilation interface according to claim 1, characterized in that, It also includes a ventilation gas tube terminating at the nozzle, wherein at least a portion of the pressure sensing tube is disposed within the ventilation gas tube.

8. The patient ventilation interface according to claim 7, characterized in that, The pressure sensing tube extends from the ventilation gas tube into the throat body to position the pressure sensing port in fluid communication with the inflation chamber.

9. The patient ventilation interface according to claim 8, characterized in that, The pressure sensing port of the pressure sensing tube is in fluid communication with the inflation chamber through a pressure sensing channel defined by the throat body.

10. The patient ventilation interface according to claim 1, characterized in that, It also includes an inlet member defining a Venturi inlet in fluid communication with the Venturi throat, wherein the nozzle is arranged to output the ventilation gas to the Venturi throat through the Venturi inlet.

11. The patient ventilation interface according to claim 10, characterized in that, The inlet member defines one or more entrainment openings, through which the venturi throat is open to ambient air.

12. The patient ventilation interface according to claim 11, characterized in that, The nozzle is arranged to deliver the ventilation gas to the venturi inlet through one or more entrainment openings.

13. The patient ventilation interface according to claim 12, characterized in that, The venturi inlet opens outward relative to the venturi throat.

14. A non-invasive ventilation system, comprising: The patient ventilation interface according to claim 1; as well as A pressure sensor that is fluidly connected to the pressure sensing tube.

15. The non-invasive ventilation system according to claim 14, characterized in that, It also includes a controller programmed to respond to the patient airway pressure P sensed by the pressure sensor. sense To control the delivery of the ventilation gas output from the nozzle.

16. The non-invasive ventilation system according to claim 15, characterized in that, The controller is programmed to correct the sensed patient airway pressure P. sense The expected error in the calculation.

17. The non-invasive ventilation system according to claim 16, characterized in that, The controller is programmed to apply the sensed patient airway pressure P. sense Index correction factor P delta To correct the expected error.

18. The non-invasive ventilation system according to claim 17, characterized in that, The correction factor P delta Also determined by the nozzle flow rate V' of the nozzle n index.

19. The non-invasive ventilation system according to claim 14, characterized in that, It also includes a non-transitory program storage medium storing instructions that can be executed by a processor or programmable circuitry to correct the sensed patient airway pressure P. sense The expected error in the calculation.

20. The non-invasive ventilation system according to claim 19, characterized in that, The instructions can be executed by a processor or programmable circuitry to apply the sensed patient airway pressure P. sense Index correction factor P delta To correct the expected error.

21. The non-invasive ventilation system according to claim 20, characterized in that, The correction factor P delta Also determined by the nozzle flow rate V' of the nozzle n index.

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