Filter assembly for therapeutic gas delivery device

Abstract

A sample gas filter assembly (100) for a therapeutic gas delivery device is disclosed herein. The filter assembly comprises:-a filter device (106) comprising an inlet (102), an outlet (124) and at least one reservoir (118) and at least one filter membrane (316) located between the inlet and the outlet, wherein the filter apparatus is operable to remove water vapor from the sample gas and collect condensate in the at least one reservoir; -a permeable tubular membrane (300), said permeable tubular membrane being fluidly connected to said outlet of said filter device; and-a vent cap (114) connected to the filter device and surrounding the outlet, the vent cap comprising a vent hole (116). The sample gas filter assembly is configured to maintain condensate pH from an assembly for humidity regulation and filtration of a sample gas in a therapeutic gas delivery device.

Description

Technical Field

[0001] The present disclosure relates to a patient sample gas filter assembly and methods of use thereof. More particularly, the present disclosure relates to a patient sample gas filter assembly comprising a filter system for filtering liquid from a sample gas in a therapeutic gas delivery system. Background Art

[0002] Therapeutic gases can be delivered to a patient via inspired respiratory gas flowing through a breathing circuit associated with a ventilator. For example, therapeutic gases can be injected into inspired respiratory gas flowing through a breathing circuit and subsequently delivered to the patient's airway. One such therapeutic gas is nitric oxide, which can produce a vasodilatory effect on the patient.

[0003] While administering the therapeutic gas, the gas sensor module can monitor a portion of the inhaled respiratory gas to confirm that the therapeutic gas is being delivered to the inhaled respiratory gas stream at the desired dose. For example, a patient gas sample line and a sample gas filter assembly can be used to provide sample gas (e.g., a portion of the inhaled respiratory gas stream) to the gas sensor module, which monitors the concentration of the therapeutic gas delivered to the patient. In some cases, the breathing circuit that delivers the therapeutic gas to the patient's airway can be humidified. Traditionally, the patient gas sample line and the sample gas filter assembly involve a complex design for separating liquid from the sample gas. However, these designs may be difficult to manufacture and may require the patient gas sample line and the sample gas filter assembly to be in a specific orientation during use. In addition, these designs may allow wicking to occur between multiple filtration stages, which may lead to premature clogging. Traditionally, permeable tubing has been used to filter water from the sample gas before the sample gas enters the filter. However, the permeable tubing can react with the salt water in the sample gas to produce hydrochloric acid, which can corrode the sampling sensor and other components, resulting in the need to replace the components before the expected lifespan. Additionally, salt water in the sample gas may react with the water permeable tubing, causing blockages within the water permeable tubing.

[0004] Therefore, a need exists for a patient gas sample line and sample gas filter assembly that is easier to manufacture, easier to use, and longer lasting. Summary of the Invention

[0005] Aspects of the present disclosure include an assembly for a therapeutic gas delivery device. The assembly may include a filter device, a water-permeable tubular membrane, and a vent cap. The filter device may have an inlet, an outlet, at least one fluid reservoir, and at least one filter membrane. The filter membrane may be located between the inlet and the outlet. The filter device may be operable to remove water vapor from the sample gas and collect condensate in the at least one fluid reservoir. The water-permeable tubular membrane may be fluidically connected to the outlet of the filter device. The vent cap may be connected to the filter device and surround the outlet. The vent cap may have ventilation holes.

[0006] In some cases, the water permeable tubular membrane can be configured to humidity condition the sample gas.

[0007] In some cases, the vent cap may have a plurality of vent holes. In some cases, the vent cap is configured to receive and secure the water-permeable tubular membrane.

[0008] In some cases, the water permeable tubular membrane is formed from a sulfonated tetrafluoroethylene based fluoropolymer-copolymer. In some cases, the water permeable tubular membrane is a pipe comprising a sulfonated tetrafluoroethylene based fluoropolymer-copolymer.

[0009] Aspects of the present disclosure include a filter apparatus for a therapeutic gas delivery device. The filter apparatus may have a housing, a first chamber, and a second chamber. The housing may include a sample gas inlet and a sample gas outlet. The sample gas inlet may be operable to receive a gas sample from a sample line connected to an intake line of the therapeutic gas delivery device. The first chamber may be located within the housing and have a first filter membrane and a first fluid reservoir between the sample gas inlet and the first filter membrane. The second chamber may be located within the housing and have a second filter membrane and a second fluid reservoir between the first filter membrane and the sample gas outlet.

[0010] In some cases, the first reservoir and the second reservoir are axially oriented such that the filter device can be operable for use in any axial orientation. In some cases, the housing, each of the chambers, and each of the filter membranes can have a substantially circular cross-section.

[0011] In some cases, the at least one reservoir can be large enough to hold water for 12 hours of continuous use. In some cases, the at least one reservoir can have a volume of at least 10 cubic centimeters. In some cases, the assembly can be configured to be installed in the therapeutic gas delivery device in one hand.

[0012] Aspects of the present disclosure include a method for humidity conditioning and filtering a sample gas in a therapeutic gas delivery device. The method may include passing the sample gas through a filter device of an assembly; collecting condensate from the sample gas in the filter device; and passing the filtered gas through a water-permeable tubular membrane of the assembly. The sample gas exiting the water-permeable tubular membrane may be humidity-conditioned sample gas.

[0013] In some cases, the sample gas exiting the water permeable tubular membrane can be humidity-conditioned sample gas at a confidence level of at least 98%, at least 99%, at least 99.5%, at least 99.9%, or at least 99.95%.

[0014] In some cases, the outer surface of the water permeable tubular membrane may be exposed to ambient air flow.

[0015] In some cases, the humidity-conditioned sample gas can be substantially free of saline. In some cases, the generation of hydrochloric acid (HCl) within the therapeutic gas delivery device can be reduced or prevented.

[0016] In some cases, with a confidence level of at least 98%, blockage of a sample line connected to the assembly, blockage of a pump connected to the sample line, corrosion of the filter device, and / or corrosion in the therapeutic gas apparatus can be reduced or prevented.

[0017] In some cases, the assembly can maintain the pH of the condensate at about 5.0 to about 6.0, about 5.3 to about 5.6, or about 5.4 to about 5.6.

[0018] Aspects of the present disclosure include a method for maintaining the pH of condensate from an assembly for humidity conditioning and filtering a sample gas in a therapeutic gas delivery device. The method may include passing the sample gas through a filter device of the assembly; collecting condensate from the sample gas in the filter device; and passing the filtered sample gas through a water-permeable tubular membrane of the assembly. The sample gas exiting the water-permeable tubular membrane may be humidity-conditioned sample gas. The assembly may maintain the pH of the condensate at a pH of about 5.0 to about 6.0.

[0019] In some cases, the humidity-conditioned sample gas can be substantially free of saline. In some cases, the outer surface of the water-permeable tubular membrane can be exposed to ambient airflow. In some cases, the assembly can reduce or prevent the generation of HCl within the therapeutic gas delivery device.

[0020] In some cases, the assembly can reduce or prevent clogging of a sample line connected to the assembly, clogging of a pump connected to the sample line, corrosion of the filter device, or corrosion in the therapeutic gas delivery apparatus.

[0021] Aspects of the present disclosure include a method for preventing degradation or corrosion in a therapeutic gas delivery device. The method may include passing a sample gas through a filter device of an assembly; collecting condensate from the sample gas in the filter device; passing the filtered sample gas through a water-permeable tubular membrane of the assembly; and preventing the sample gas from contacting a sensor without first being humidity-conditioned with a confidence level of at least 98%. The sample gas exiting the water-permeable tubular membrane may be humidity-conditioned sample gas.

[0022] Aspects of the present disclosure include a method for preventing degradation or corrosion in a therapeutic gas delivery device. The method may include passing a sample gas through a filter device of an assembly; collecting condensate from the sample gas in the filter device; passing the filtered sample gas through a water-permeable tubular membrane of the assembly; and maintaining the pH of the condensate at a level of at least 98% confidence of about 5.0 to about 6.0. The sample gas exiting the water-permeable tubular membrane may be humidity-conditioned sample gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The description will be more fully understood with reference to the following drawings and data diagrams, which present various embodiments of the present disclosure and should not be construed as a complete description of the scope of the present disclosure. It should be noted that for the purpose of clarity of illustration, some elements in the various drawings may not be drawn to scale. It should be understood that these drawings depict only exemplary embodiments of the present disclosure and are therefore not to be considered as limiting its scope. The principles of this document are described and explained in more detail and detail through the use of the accompanying drawings, in which:

[0024] Figure 1 is a cross-sectional view of the sample gas filter assembly.

[0025] Figure 2 is a cross-sectional view of the vent hood.

[0026] Figure 3 is a cross-sectional view of the sample gas filter assembly.

[0027] Figure 4 is a cross-sectional view of the sample gas filter assembly.

[0028] Figure 5 is a perspective view of the sample gas filter assembly.

[0029] Figure 6 is a cross-sectional view of the sample gas filter assembly.

[0030] Figure 7 is a flow chart of an example method.

[0031] Figure 8 is a flow chart of an example method.

[0032] Figure 9 is a flow chart of an example method.

[0033] Figure 10 is a flow chart of an example method. DETAILED DESCRIPTION

[0034] It should be understood that for simplicity and clarity of explanation, where appropriate, reference numerals have been repeated in different figures to indicate corresponding or similar elements. In addition, many specific details are set forth to provide a thorough understanding of the examples described herein. However, those skilled in the art will understand that the examples described herein can be practiced without these specific details. In other cases, methods, procedures, and components have not been described in detail to avoid obscuring the relevant features described. In addition, the description should not be construed as limiting the scope of the embodiments described herein. The drawings are not necessarily drawn to scale, and the proportions of certain parts may be exaggerated to better illustrate the details and features of the present disclosure.

[0035] Several definitions applicable throughout the above disclosure will now be presented.

[0036] As used herein, the term "coupled" is defined as connected, whether directly or indirectly through intermediate components, and is not necessarily limited to physical connections. A connection can be such that the objects are permanently connected or releasably connected.

[0037] The term "substantially" is defined as substantially conforming to substantially modified specific dimensions, shapes, or other terms such that the components do not necessarily need to be exact.

[0038] The terms "comprising," "including," and "having" are used interchangeably in this disclosure. The terms "comprising," "including," and "having" are meant to include, but not necessarily be limited to, the contents so described.

[0039] The terms "filter" and "filtration" are used herein in their broadest sense to encompass any and all types and degrees of removal or separation of liquids from gases, and in some cases may also include the removal of other non-liquid particles that are present.

[0040] The term "liquid" is used herein in its broadest sense to encompass moisture, water vapor, moisture in humidified air, other liquids in vaporous state, aerosolized liquids, aerosolized drug solutions (eg, saline solutions) and suspensions, and the like.

[0041] The terms "humidity adjustment" and "humidification adjustment" refer to adjusting the relative humidity of a gas (e.g., a sample gas) to match the humidity of the ambient air. Thus, when the relative humidity of the sample gas is lower than the ambient air, moisture will flow into the sample gas, or when the relative humidity of the sample gas is higher than the ambient air, moisture will flow out of the sample gas.

[0042] The present disclosure relates to a patient gas sample line and sample gas filter assembly, as well as methods of use thereof. The filter comprises a multi-stage filtration system having a liquid reservoir, which filters liquid from a sample gas containing liquid (e.g., a portion of a mixture of respiratory gas and therapeutic gas). The liquid component can be any removable liquid, such as moisture, water vapor, moisture from humidified air, other liquids in vapor form, aerosolized liquids, aerosolized drug solutions (e.g., saline solutions), and suspensions.

[0043] The sample gas filter assembly can be used in a therapeutic gas delivery system that delivers a therapeutic gas (e.g., nitric oxide) to a patient's airway. The therapeutic gas is delivered to the patient by being administered into a breathing circuit, which is typically connected to a mechanical ventilator by a pipeline. A subsystem of the therapeutic gas delivery system contains a gas sensor module having one or more gas sensors that monitors the concentration of the therapeutic gas and / or other gases delivered to the patient. The gas sensor module is connected to the same patient breathing circuit as the therapeutic gas delivery system.

[0044] The sample gas filter assembly may be more convenient to use than a conventional patient gas sample line and filter. For example, the sample gas filter assembly may be easier to manufacture (e.g., it may involve only one or two manufacturing steps). Additionally, the sample gas filter assembly may be used in any axial orientation.

[0045] Traditionally, the sample gas filter assembly is configured to receive sample gas from the patient's breathing circuit at the gas sample tee. The sample gas is then transferred to the filter through a water-permeable tubular membrane. However, the configuration of this sample gas filter assembly, i.e., the water-permeable tubular membrane delivers the sample gas to the filter, can cause corrosion and blockage problems along the flow path and into the gas sensor module. When the sample gas enters the water-permeable tubular membrane before being filtered, the water-permeable tubular membrane may react with cations found in the sample gas, such as sodium found in salt water. The water-permeable tubular membrane can contain sulfonic acid receptor sites in a polytetrafluoroethylene (PTFE) matrix. These sites can be combined with any cation (e.g., sodium found in salt water, which is commonly used for therapeutic gases). When the sodium in the sample gas combines with the water-permeable tubular membrane, chlorine is freed to combine with hydrogen, thereby producing hydrochloric acid. When hydrochloric acid is produced in the form of vapor, it will not be captured by the filter device and may flow into the gas sensor module, thereby corroding the sample sensor, sample pump, and other components in the therapeutic gas delivery device. Corrosion caused by hydrochloric acid may also occur in the filter device. Additionally, when sodium cations in the salt water react with the water-permeable tubular membrane, accumulation may occur, thereby causing blockage in the water-permeable tubular membrane.

[0046] This disclosure provides a novel solution to the problem of saltwater interacting with water-permeable tubular membranes. By reconfiguring the sample gas filter assembly to filter the sample gas using a filter device before it passes through the water-permeable tubular membrane, sodium chloride can be filtered before it comes into contact with the water-permeable tubular membrane. By filtering the sodium chloride before it comes into contact with the water-permeable tubular membrane, downstream corrosion and clogging issues are avoided.

[0047] Figure 1 An example of a sample gas filter assembly 100 is shown. The sample gas filter assembly 100 may include a sample gas inlet 102, a sample gas outlet 124, an assembly outlet 104, a filter device 106 (e.g., a sample gas filter), a vent cap 114, and a water permeable tubular membrane ( Figure 1 not shown).

[0048] The filter device 106 may include a housing 126 having a sample gas inlet 102 and a sample gas outlet 124. The sample gas inlet 102 may be in fluid communication with the sample gas outlet 124, thereby establishing a fluid flow path in the filter device 106 (e.g., from the sample gas inlet 102 to the sample gas outlet 124).

[0049] The sample gas inlet 102 can receive the sample gas and pass it into the filter device 106. In one example, the sample gas inlet 102 can receive the sample gas from a first portion of a sample line connected to an inhalation line of a therapeutic gas delivery device (e.g., through a gas sample tee). For example, the sample gas inlet 102 can be removably coupled to the sample line, which can be removably coupled to the inhalation line at the sample gas tee, thereby establishing fluid communication between the inhalation line and the filter device 106. In another example, the sample gas line can be connected to an exhalation line of a therapeutic gas delivery system. In other examples, the sample gas line can be connected to any type of gas line, as long as it is necessary to sample a gas or combination of gases to determine the concentration.

[0050] The sample gas outlet 124 can discharge the sample gas from the filter device 106. As discussed below, the sample gas can then flow through the permeable tubular membrane. The sample gas can flow out of the sample gas filter assembly 100 at the assembly outlet 104, where it can be delivered to the gas sensor module in the therapeutic delivery device by the second portion of the sample line. The assembly outlet 104 can be configured to be detachably coupled to a joint (e.g., a Luer fitting). For example, in one case, the assembly outlet 104 can extend outward from the sample gas filter assembly 100 (e.g., away from the sample gas filter assembly) and can include an external thread 122 to be detachably coupled to a joint. In another case, the assembly outlet 104 can include an internal thread to be detachably coupled to a joint. The configuration (e.g., external or internal thread) of the assembly outlet 104 can be relative to the connector (e.g., at the sample gas inlet 102) of the first portion of the sample line so that the sample gas filter assembly is unidirectional.

[0051] A sample gas pump can be used to pump sample gas from sample gas filter assembly 100 to the gas sensor module. The sample gas pump can generate a fluid flow of sample gas from sample gas inlet 102 through assembly outlet 104 and into the gas sensor module.

[0052] The first chamber 110 can be located within the housing 126. In other words, the housing 126 of the filter device 106 can fully or partially define the first chamber 110. In one embodiment, the first chamber 110 can have a substantially circular cross-section, which can define a diameter of the first chamber 110. The first chamber 110 can house a first liquid reservoir 118. The filter device 106 can remove liquid (e.g., moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized drug solutions and suspensions, etc.) from the sample gas (e.g., via a filter membrane, as discussed in further detail below) and collect the liquid in the first liquid reservoir 118. The first liquid reservoir 118 can be oriented axially along the length of the filter so that the filter device 106 can operate (e.g., remove liquid from the sample gas and collect the liquid) in any orientation during operation. The first liquid reservoir 118 can define a volume and, in some embodiments, can be configured to hold liquid for approximately twelve hours of continuous use before requiring replacement and / or emptying.

[0053] The volume of the first liquid reservoir 118 can be about 5 cubic centimeters to about 10 cubic centimeters, about 10 cubic centimeters to about 15 cubic centimeters, about 15 cubic centimeters to about 20 cubic centimeters, about 20 cubic centimeters to about 25 cubic centimeters, about 25 cubic centimeters to about 30 cubic centimeters, about 30 cubic centimeters to about 35 cubic centimeters, about 35 cubic centimeters to about 40 cubic centimeters, about 40 cubic centimeters, or more.

[0054] The second chamber 112 can be located within the housing 126. In other words, the housing 126 of the filter device 106 can fully or partially define the second chamber 112. In one embodiment, the second chamber 112 can have a substantially circular cross-section, which can define a diameter of the second chamber 112. The second chamber 112 can house a second liquid reservoir 120. The filter device 106 can remove liquid (e.g., moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized drug solutions and suspensions, etc.) from the sample gas (e.g., via a filter membrane, as discussed in further detail below) and collect the liquid in the second liquid reservoir 120. The second liquid reservoir 120 can be oriented axially along the length of the filter so that the filter device 106 can operate in any orientation during operation (e.g., remove liquid from the sample gas and collect the liquid). The second liquid reservoir 120 can define a volume and, in some embodiments, can be configured to hold liquid for approximately twelve hours of continuous use before requiring replacement.

[0055] The volume of the second reservoir 120 can be about 1 cubic centimeter to about 5 cubic centimeters, about 5 cubic centimeters to about 10 cubic centimeters, about 10 cubic centimeters to about 15 cubic centimeters, about 15 cubic centimeters to about 20 cubic centimeters, about 20 cubic centimeters, or more. In some examples, the volume of the second reservoir 120 can be less than the volume of the first reservoir 118. In another example, the volume of the second reservoir 120 can be greater than the volume of the first reservoir 118. In some examples, the first reservoir 118 and the second reservoir 120 can have the same or substantially the same volume.

[0056] The sample gas filter assembly 100 may include a vent cap 114. The vent cap may include one or more vent holes 116. The vent holes may be rectangular in shape, such as Figure 1 The ventilation holes 116 may have other shapes, such as Figure 3-6 As shown. The vents 116 can have any shape that allows air to flow into the cowl 114. The cowl 114 can be configured to accommodate and secure the water-permeable tubular membrane. For example, the cowl 114 can have a water-permeable tubular membrane holder 108 for securing the water-permeable tubular membrane.

[0057] Figure 2 One example of a vent cap 114 is shown. The sample gas filter assembly 100 can have a vent cap 114 that includes a plurality of vent holes 116. The gas filter assembly 100 can include a water permeable tubular membrane inlet conduit 204, a water permeable tubular membrane inlet port 200, a water permeable tubular membrane outlet port 202, a sample gas outlet conduit 206, a sample gas outlet 124, and an assembly outlet 104.

[0058] Permeable tubular membrane ( Figure 2 A water permeable tubular membrane inlet conduit 204 (not shown) can be connected to the water permeable tubular membrane inlet port 200 and the water permeable tubular membrane outlet port 202, thereby establishing a fluid flow path between the water permeable tubular membrane inlet port 200 and the water permeable tubular membrane outlet port 202. The water permeable tubular membrane inlet conduit 204 can provide sample gas to the water permeable tubular membrane at the water permeable tubular membrane inlet port 200. The sample gas outlet conduit 206 can flow the sample gas from the water permeable tubular membrane outlet port 202 to the assembly outlet 104.

[0059] In one instance, the water permeable tubular membrane inlet port 200 may be connected to the water permeable tubular membrane inlet conduit 204 at a 30 degree angle, such as for example Figure 2 The sample gas may be provided to the water permeable tubular membrane by flowing out of the sample gas outlet 124 , passing through the water permeable tubular membrane inlet conduit 204 , and entering the water permeable tubular membrane at the water permeable tubular membrane inlet port 200 .

[0060] The water permeable tubular membrane inlet port 200 can be connected to the water permeable tubular membrane inlet conduit 204 at the following angles: an angle of about 10 degrees to an angle of about 20 degrees, an angle of about 20 degrees to an angle of about 30 degrees, an angle of about 30 degrees to an angle of about 40 degrees, an angle of about 40 degrees to an angle of about 50 degrees, an angle of about 50 degrees to an angle of about 60 degrees, an angle of about 60 degrees to an angle of about 70 degrees, an angle of about 70 degrees to an angle of about 80 degrees, an angle of about 80 degrees to an angle of about 90 degrees (e.g., Figure 3 ), an angle of about 90 degrees to about 100 degrees, an angle of about 100 degrees to about 110 degrees, an angle of about 110 degrees to about 120 degrees, an angle of about 120 degrees to about 130 degrees, an angle of about 130 degrees to about 140 degrees, an angle of about 140 degrees to about 150 degrees, an angle of about 150 degrees to about 160 degrees, or an angle of about 160 degrees to about 170 degrees.

[0061] The water permeable tubular membrane outlet port 202 may be connected to the sample gas outlet conduit 206 at a 30 degree angle, such as for example Figure 2 The sample gas may exit the water permeable tubular membrane at the water permeable tubular membrane outlet port 202 and flow through the sample gas outlet conduit 206 to the assembly outlet 104 .

[0062] The water permeable tubular membrane outlet port 202 can be connected to the outlet conduit at an angle of about 10 degrees to about 20 degrees, an angle of about 20 degrees to about 30 degrees, an angle of about 30 degrees to about 40 degrees, an angle of about 40 degrees to about 50 degrees, an angle of about 50 degrees to about 60 degrees, an angle of about 60 degrees to about 70 degrees, an angle of about 70 degrees to about 80 degrees, an angle of about 80 degrees to about 90 degrees (e.g., Figure 3 ), an angle of about 90 degrees to about 100 degrees, an angle of about 100 degrees to about 110 degrees, an angle of about 1110 degrees to about 120 degrees, an angle of about 120 degrees to about 130 degrees, an angle of about 1130 degrees to about 140 degrees, an angle of about 140 degrees to about 150 degrees, an angle of about 150 degrees to about 160 degrees, or an angle of about 160 degrees to about 170 degrees.

[0063] Figure 3An example of a sample gas filter assembly 100 is shown. The sample gas filter assembly 100 can include a filter device 106 having a sample gas inlet 102 and a sample gas outlet 124. The sample gas filter assembly 100 can have a vent cap 114 configured to surround and contain a water permeable tubular membrane 300 and having a sample gas outlet 124 and an assembly outlet 104. The sample gas inlet 102 can be in fluid communication with the assembly outlet 104, thereby establishing a fluid flow path in the sample gas filter assembly 100 (e.g., from the sample gas inlet 102 to the assembly outlet 104).

[0064] The housing 126 of the filter device 106 can define an outer surface 302 and an inner surface 304 opposite the outer surface 302, such as, for example Figure 3 The thickness of the housing 126 can be defined by the distance between the outer surface 302 and the inner surface 304. The housing can have a substantially circular cross-section, which can define the diameter of the housing 126.

[0065] In one embodiment, the housing 126 can include a first shell 306 and a second shell 308, each of which can define a portion of the outer surface 302 and the inner surface 304 of the housing 126. The first shell 306 can define a first surface 312 opposite the sample gas inlet 102. The second shell 308 can define a second surface 310 opposite the sample gas outlet 124. The first surface 312 of the first shell 306 can be fully or partially aligned with the second surface 310 of the second shell 308 to form a water-tight housing 126. In one embodiment, ultrasonic welds 314 can couple the first and second shells 306, 308 at the first and second surfaces 312, 310.

[0066] The first chamber 110 can be located within the housing 126. In other words, the housing 126 of the filter device 106 can fully or partially define the first chamber 110. In one embodiment, the first chamber 110 is partially defined by the inner surface 304 of the first shell 306. In one embodiment, the first chamber 110 can have a substantially circular cross-section, which can define a diameter of the first chamber 110.

[0067] The second chamber 112 can be located within the housing 126. In other words, the housing 126 of the filter device 106 can fully or partially define the second chamber 112. In one embodiment, the second chamber 112 is partially defined by the inner surface 304 of the second shell 308. In one embodiment, the second chamber 112 can have a substantially circular cross-section, which can define a diameter of the second chamber 112.

[0068] For example Figure 3 The illustrated first filter membrane 316 (e.g., a first stage of filtration) can be included in the first chamber 110. In one embodiment, the first filter membrane 316 can be substantially circular in shape, which can define a diameter of the first filter membrane 316. The first filter membrane 316 can remove liquid (e.g., moisture, water vapor, moisture from humidified air, other liquids in vapor form, aerosolized liquids, aerosolized drug solutions and suspensions, etc.) from the sample gas (e.g., the sample gas flows through the first filter membrane 316) and can coalesce and collect the liquid in the first reservoir 118 (e.g., a front reservoir), such as, for example Figure 1 In some cases, the first filter membrane 316 can be coalesced into a liquid that is both oleophobic and hydrophobic. In one embodiment, the first filter membrane 316 can be a glass fiber filter membrane.

[0069] In some cases, the first filter membrane 316 can be held in place (eg, fixed) and / or sealed by the engagement of the first surface 312 of the first housing 306 with the second surface 310 of the second housing 308, as in, for example, Figure 3 and 6 For example, the ultrasonic weld 314 connecting the first surface 312 and the second surface 310 can secure and / or seal the first filter membrane 316.

[0070] For example Figure 1 As shown, the first liquid reservoir 118 can be included in the first chamber 110 (e.g., integrated into the housing 126). In some cases, the first liquid reservoir 118 can be located between the sample gas inlet 102 and the first filter membrane 316. In other cases, the first liquid reservoir can be located between the sample gas inlet 102 and a baffle (discussed in further detail below). The filter device 106 can remove liquid (e.g., moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized drug solutions and suspensions, etc.) from the sample gas (e.g., through the first filter membrane 316) and collect the liquid in the first liquid reservoir 118. The first liquid reservoir can be oriented axially along the length of the filter so that the filter device 106 can operate in any orientation during operation (e.g., remove liquid from the sample gas and collect the liquid). The first liquid reservoir 118 can define a volume and, in some cases, can be configured to hold water for approximately twelve hours of continuous use before requiring replacement.

[0071] For example Figure 3As shown, a second filter membrane 320 (e.g., a second stage of filtration) can be included in the second chamber 112. In one embodiment, the second filter membrane can be substantially circular in shape, which can define a diameter of the second filter membrane 320. The second filter membrane 320 can remove liquid from the sample gas (e.g., the sample gas flowing through the second filter membrane 320) and cause the liquid to coalesce and collect in the second reservoir 120 (e.g., a back reservoir), such as, for example Figure 1 In some cases, the second filter membrane 320 can be a hydrophobic membrane.

[0072] In some examples, the diameter of the second filter membrane 320 can be smaller than the diameter of the first filter membrane 316. In other words, the diameter of the first filter membrane 316 can be larger than the diameter of the second filter membrane 320, such as Figure 3 shown.

[0073] In some cases, the first filter membrane 316 can be separated from the second filter membrane 320 to prevent wicking between the first filter membrane 316 and the second filter membrane 320. For example, a gap can exist between the first filter membrane 316 and the second filter membrane 320 to prevent wicking, such as Figure 3 shown.

[0074] For example Figure 1 As shown, the second reservoir 120 can be included in the second chamber 112 (e.g., integrated into the housing 126). In some cases, the second reservoir 120 can be located between the first filter membrane 316 and the sample gas outlet 124. In other cases, the second reservoir 120 can be located between the fiber membrane of the first chamber 110 and the press-fit baffle 318. The filter device 106 can remove liquid (e.g., moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized drug solutions and suspensions, etc.) from the sample gas (e.g., through the second filter membrane 320) and collect the liquid in the second reservoir 120. The second reservoir 120 can be oriented axially along the length of the filter so that the filter device 106 can operate (e.g., remove liquid from the sample gas and collect liquid) in any orientation during operation. The second reservoir 120 can define a volume and, in some cases, can be configured to hold water for approximately twelve hours of continuous use without requiring replacement.

[0075] The first reservoir 118 and the second reservoir 120 can be axially oriented so that the filter device 106 can operate in any axial orientation. In some cases, the first reservoir 118 and the second reservoir 120 can be large enough (e.g., have sufficient volume) to hold water for at least twelve hours of continuous use. In some cases, the volume of the second reservoir 120 can be smaller than the volume of the first reservoir 118. In other words, the volume of the first reservoir 118 can be larger than the volume of the second reservoir 120, such as, for example Figure 1 shown.

[0076] For example Figure 3 As shown, a press-fit baffle 318 can be included in the second chamber 112. In some examples, the press-fit baffle 318 can mechanically support the second filter membrane 320 on a first side of the second filter membrane 320 (eg, a front side facing the sample gas flow).

[0077] For example Figure 3 As shown, a labyrinth support 322 can be included in the second chamber 112. The labyrinth support 322 can be located on the inner surface 304 of the housing 126, proximate to the water-permeable tubular membrane inlet conduit 204 (e.g., the inner surface 304 of the second housing 308). In some examples, the labyrinth support 322 can mechanically support the second filter membrane 320 on a second side (e.g., the back side, i.e., facing away from the sample gas flow) of the second filter membrane 320. Additionally, the labyrinth support 322 can facilitate efficient circulation of the sample gas behind the second filter membrane 320.

[0078] The first filter membrane 316 and the second filter membrane 320 can both be hydrophobic and / or oleophobic. The hydrophobic and / or oleophobic properties of the first filter membrane 316 and the second filter membrane 320 can filter liquids (e.g., moisture, water vapor, moisture in humidified air, other liquids in vapor state, atomized liquids, atomized drug solutions and suspensions, etc.) from the sample gas. One of the liquids that can be filtered is a saline solution (e.g., NaCl). By filtering the sample gas before it enters the permeable tubular membrane 300, the reaction between the sodium in the saline solution and the permeable tubular membrane 300 can be prevented or reduced. Preventing or reducing the reaction between sodium and other cations and the permeable tubular membrane can avoid the generation of hydrochloric acid, thereby preventing corrosion in the sample line, gas sensor module, filter equipment and therapeutic gas delivery device caused by hydrochloric acid. Additionally, by filtering the sample gas before it flows through the permeable tubular membrane, blockage (e.g., clogging) in the sample line and the permeable tubular membrane can be prevented or reduced.

[0079] The filter device 106 can maintain the pH of the condensate collected within the filter device 106 at a level of about 5.0 to about 6.0. By maintaining the pH at a level of about 5.0 to about 6.0, the filter device 106 can ensure that liquids within the sample gas that react with the water-permeable tubular membrane 300 (e.g., saline solution (NaCl)) are filtered before entering the water-permeable tubular membrane 300. Preventing NaCl from entering the water-permeable tubular membrane 300 avoids the water-permeable tubular membrane 300 from reacting with the sodium in the saline, thereby eliminating the risk of downstream corrosion or blockage in the therapeutic gas delivery device and the sample gas filter assembly 100.

[0080] In other instances, the pH of the condensate may be at a level of about 5.3 to about 6.0. In another instance, the pH of the condensate may be at a level of about 5.4 to about 5.6.

[0081] Prior to entering the water-permeable tubular membrane 300, the filtered sample gas can be substantially free of saline. In some examples, the filtered sample gas can be approximately 98% to approximately 98.5%, approximately 98.5% to approximately 99%, approximately 99% to approximately 99.5%, approximately 99.5% to approximately 99.95%, or approximately 99.95% to approximately 99.99% free of saline. In one example, the filtered sample gas can be substantially free of saline. In another example, the filtered sample gas can be 100% free of saline.

[0082] The sample gas filter assembly 100 may include a vent cap 114 that may be connected to the filter device 106. The vent cap 114 may be removably coupled to the second housing 308 of the filter device 106 at the outer surface 302. For example, Figure 3 As shown, the cowl can be removably coupled to the outer surface 302 of the second housing 308 via a snap-fit ​​connection. The cowl can also be connected to the filter device 106 using other connection methods, such as screws, barb-fit connections, or other connection mechanisms.

[0083] For example Figure 3 As shown, the water permeable tubular membrane 300 can be fluidly connected to the water permeable tubular membrane inlet port 200 at one end and to the water permeable tubular membrane outlet port 202 at the other end. The water permeable tubular membrane 300 can be housed within the cowl 114. The water permeable tubular membrane 300 can be attached to the water permeable tubular membrane holder 108 to secure the water permeable tubular membrane 300 within the cowl. For example, Figure 1 As shown, the water permeable tubular membrane holder 108 may be shaped like a hook.

[0084] In one example, the sample gas outlet 124 can discharge sample gas from the filter device 106 to the water permeable tubular membrane inlet conduit 204. The water permeable tubular membrane inlet conduit 204 can provide filtered sample gas to the water permeable tubular membrane 300 at the water permeable tubular membrane inlet port 200. The water permeable tubular membrane 300 can discharge the sample gas at the water permeable tubular membrane outlet port 202. The sample gas can flow through the sample gas outlet conduit 206 and be discharged to a gas sensor module of the therapeutic gas delivery device at the assembly outlet 104.

[0085] The water permeable tubular membrane 300 can be made of a sulfonated tetrafluoroethylene based fluoropolymer-copolymer. In one embodiment, the water permeable tubular membrane 300 can be made of a sulfonated tetrafluoroethylene based fluoropolymer-copolymer (e.g., ) pipes made of.

[0086] The permeable tubular membrane 300 can be configured to humidity regulate the sample gas. The permeable tubular membrane 300 can be exposed to ambient air flow through the vent holes 116 in the vent cap 114. The permeable tubular membrane 300 can humidity regulate the sample gas by regulating the sample gas to match the humidity of the ambient air. The permeable tubular membrane 300 can remove water vapor from the sample gas to reduce the humidity of the sample gas, thereby matching it with the humidity of the ambient air. In other examples, if the humidity of the sample gas is lower than the humidity of the ambient air, the permeable tubular membrane 300 can improve the humidity of the sample gas. The humidity-regulated sample gas can then flow through the assembly outlet 104 and enter the gas sensor module, where the sample gas is analyzed. Humidity regulating the sample gas before it enters the sensor of the gas sensor module provides more accurate readings and improves the service life of other components in the sensor, therapeutic delivery device, and sample gas filter assembly 100.

[0087] The humidity-conditioned gas can be substantially free of brine. In some cases, the humidity-conditioned gas can be 98%, 98.5%, 99%, 99.5%, 99.95%, or 99.99% free of brine.

[0088] Figure 4 An example of a sample gas filter assembly 100 is shown. In some cases, a baffle 400 can be included in the first chamber 110, such as, for example Figure 4 In some examples, the baffle 400 can mechanically support the first filter membrane 316 on a second side (eg, a back side, ie, facing away from the sample gas flow) of the first filter membrane 316 .

[0089] Figure 5An example of a sample gas filter assembly 100 is shown. The sample gas filter assembly can provide a fluid flow path for a sample gas from a sample gas inlet 102 to an assembly outlet 104. The sample gas filter assembly 100 can be configured for single-handed installation.

[0090] Figure 6 An example of a sample gas filter assembly 100 is shown. In some cases, a fiber membrane 600 can be included in the first chamber 110. In some examples, the fiber membrane 600 can mechanically support the first filter membrane 316 on a second side (e.g., a back side, i.e., facing away from the sample gas flow) of the first filter membrane 316. In one example, the fiber membrane 600 can be a Vyon fiber membrane.

[0091] The sample gas filter assembly, including the sample line (the line attached to the sample gas inlet 102) and / or the sample gas filter assembly 100, can be removed and replaced as needed. In other words, the existing sample line and / or sample gas filter assembly 100 can be removed from the therapeutic gas delivery device, and a new sample line and / or sample gas filter assembly 100 can be connected in its place, as previously described.

[0092] Further provided herein is a method for humidity conditioning and filtering a sample gas in a therapeutic gas delivery device. Figure 7 The flowchart shown is presented according to an example embodiment. The method is provided by way of example because there are many ways to perform the method. For example, the method 700 described below can be performed using the illustrated configuration, and reference is made to the various elements in these figures when describing the example method 700. Each box represents one or more processes, methods, or subroutines performed in the example method 700. In addition, Figure 7 The order of the blocks shown is for illustrative purposes only, and the order of the blocks may be adjusted according to the present disclosure. Additional blocks may be added, or fewer blocks may be used without departing from the present disclosure.

[0093] Example method 700 is a method for humidifying and filtering a sample gas in a therapeutic gas delivery device. The example method may begin at block 702. At block 702, the method includes passing a sample gas through a filter device (e.g., a sample gas filter) of an assembly. Sample gas may be provided to the sample gas filter at a sample gas inlet. The sample gas may flow through the sample gas inlet to a first filter membrane. The first filter membrane may be hydrophobic and / or oleophobic. Liquids (such as moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized pharmaceutical solutions and suspensions, etc.) may be filtered out of the sample gas at the first filter membrane. The first filter membrane may also filter saline solution from the sample gas. The sample gas may then pass through a second filter membrane. At the second filter membrane, liquids (such as moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized pharmaceutical solutions and suspensions, etc.) may be further filtered out of the sample gas.

[0094] At block 704, the method includes collecting condensate from the sample gas in a filter device. Liquid blocked by the first filter membrane can be collected in a first reservoir located in a first chamber of the sample gas filter. The first reservoir can also collect any saline solution blocked by the first filter membrane. Liquid can be collected in a second reservoir located in a second chamber of the sample gas filter. The collected condensate can be maintained at a condensate pH of 5.0 to 6.0. Maintaining the condensate at a pH of 5.0 to 6.0 ensures that any salt or sodium is filtered out before entering the water-permeable tubular membrane, thereby preventing any reaction in the water-permeable tubular membrane that could produce hydrochloric acid.

[0095] At block 706, the method includes passing the filtered sample gas through the water-permeable tubular membrane of the assembly. The sample gas exiting the water-permeable tubular membrane is humidity-regulated gas. The water-permeable tubular membrane may be housed in a vent cap connected to the sample gas filter. The vent cap may have at least one vent hole to allow ambient air to contact the water-permeable tubular membrane. When ambient air contacts the outer surface of the water-permeable tubular membrane, the water-permeable tubular membrane may release water vapor from the sample gas, thereby humidity-regulating the sample gas. The water-permeable tubular membrane regulates the humidity of the sample gas to the same as that of the ambient air.

[0096] The sample gas can be humidity conditioned with a confidence level of at least 98% to about 99%, about 99% to about 99.5%, about 99.5% to about 99.9%, about 99.9% to about 99.95%, or greater. The humidity conditioned gas can be substantially free of brine. The humidity conditioned gas can be about 98% to about 99%, about 99% to about 99.5%, or about 99.5% to about 99.95% free of brine. In some instances, the humidity conditioned gas can be substantially free of brine. In one instance, the humidity conditioned gas can be 100% free of brine.

[0097] By filtering liquids (including saline solutions) before they reach the water-permeable tubular membrane, the generation of hydrochloric acid is prevented or reduced. Preventing or reducing the generation of hydrochloric acid can significantly reduce corrosion of the filter apparatus and corrosion of the therapeutic gas delivery device. Additionally, by preventing sodium from reacting with the water-permeable tubular membrane, blockage of the sample line, sample pump, and / or the water-permeable tubular membrane can be significantly reduced. With a 98% confidence level, blockage of the sample line connected to the assembly, blockage of the pump connected to the sample line, corrosion of the sample gas filter, and / or corrosion in the therapeutic gas delivery device can be reduced or prevented.

[0098] The assembly can maintain the pH of the condensate at about 5.0 to about 6.0. In another example, the assembly can maintain the pH of the condensate at about 5.3 to about 6.0. In another example, the assembly can maintain the pH of the condensate at about 5.4 to about 5.6.

[0099] Further provided herein is a method for maintaining condensate pH from an assembly for humidity conditioning and filtering a sample gas in a therapeutic gas delivery device. Figure 8 The flowchart shown is presented according to an example embodiment. The method is provided by way of example because there are many ways to perform the method. For example, the method 800 described below can be performed using the illustrated configuration, and reference is made to the various elements of these figures when describing the example method 800. Each box represents one or more processes, methods, or subroutines performed in the example method 800. In addition, Figure 8 The order of the blocks shown in the figures is only illustrative, and the order of the blocks may be changed according to the present disclosure. Additional blocks may be added, or fewer blocks may be used without departing from the present disclosure.

[0100] Example method 800 is a method for maintaining condensate pH from an assembly for humidity conditioning and filtering sample gas in a therapeutic gas delivery device. The example method may begin at block 802. At block 802, the method includes passing sample gas through a filter device (e.g., a sample gas filter) of the assembly. Sample gas may be provided to the filter device at a sample gas inlet. The sample gas may flow through the sample gas inlet to a first filter membrane. The first filter membrane may be hydrophobic and / or oleophobic. Liquids (e.g., moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized pharmaceutical solutions and suspensions, etc.) may be filtered from the sample gas at the first filter membrane. The first filter membrane may also filter saline solutions from the sample gas. The sample gas may then pass through a second filter membrane. Liquids (e.g., moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized pharmaceutical solutions and suspensions, etc.) may be filtered from the sample gas at the second filter membrane.

[0101] At block 804, the method includes collecting condensate from the sample gas in a filter device. The liquid filtered by the first filter membrane can be collected in a first reservoir located in a first chamber of the filter device. The first reservoir can also collect the saline solution filtered by the first filter membrane. The liquid filtered by the second filter membrane can be collected in a second reservoir located in a second chamber of the sample gas filter. The collected condensate can be maintained at a condensate pH of 5.0 to 6.0. Maintaining the condensate at a pH of 5.0 to 6.0 ensures that any salt or sodium from the saline solution is filtered before entering the water-permeable tubular membrane, thereby preventing any reaction in the water-permeable tubular membrane that may produce hydrochloric acid.

[0102] At block 806, the method includes passing the filtered sample gas through the water-permeable tubular membrane of the assembly. The sample gas exiting the water-permeable tubular membrane is humidity-regulated gas. The water-permeable tubular membrane may be housed in a vent cap connected to the sample gas filter. The vent cap may have at least one vent hole to allow ambient air to contact the water-permeable tubular membrane. When ambient air contacts the outer surface of the water-permeable tubular membrane, the water-permeable tubular membrane may release water vapor from the sample gas, thereby humidity-regulating the sample gas. The water-permeable tubular membrane regulates the humidity of the sample gas to the same as that of the ambient air.

[0103] The sample gas can be humidity conditioned with a confidence level of at least 98%, 99%, 99.5%, 99.9%, or 99.95%. The humidity conditioned gas can be substantially free of brine. The humidity conditioned gas can be 98%, 99%, 99.5%, or 99.95% free of brine.

[0104] By filtering liquids (including saline solutions) before they reach the water-permeable tubular membrane, the generation of hydrochloric acid is prevented or reduced. Preventing or reducing the generation of hydrochloric acid can significantly reduce corrosion of the filter apparatus and corrosion of the therapeutic gas delivery device. Additionally, by preventing sodium from reacting with the water-permeable tubular membrane, blockage of the sample line, sample pump, and / or the water-permeable tubular membrane can be significantly reduced. With a 98% confidence level, blockage of the sample line connected to the assembly, blockage of the pump connected to the sample line, corrosion of the sample gas filter, and / or corrosion in the therapeutic gas delivery device can be reduced or prevented.

[0105] The method can include maintaining the pH of the condensate at about 5.0 to about 6.0. In another example, the assembly can maintain the pH of the condensate at about 5.3 to about 6.0. In another example, the assembly can maintain the pH of the condensate at about 5.4 to about 5.6.

[0106] Further provided herein is a method for preventing degradation or corrosion in a therapeutic gas delivery device. Figure 9 The flowchart shown is presented according to an example embodiment. The method is provided by way of example because there are many ways to perform the method. For example, the method 900 described below can be performed using the illustrated configuration, and reference is made to the various elements of these figures when describing the example method 900. Each box represents one or more processes, methods, or subroutines performed in the example method 900. In addition, Figure 9 The order of the blocks shown in the figures is only illustrative, and the order of the blocks may be changed according to the present disclosure. Additional blocks may be added, or fewer blocks may be used without departing from the present disclosure.

[0107] Example method 900 is a method for preventing degradation or corrosion in a therapeutic gas delivery device. The example method may begin at block 902. At block 902, the method includes passing a sample gas through a filter device (e.g., a sample gas filter) of an assembly. The sample gas may be provided to the filter device at a sample gas inlet. The sample gas may flow through the sample gas inlet to a first filter membrane. The first filter membrane may be hydrophobic and / or oleophobic. Liquids (e.g., moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized pharmaceutical solutions and suspensions, etc.) may be filtered out of the sample gas at the first filter membrane. The first filter membrane may also filter saline solution from the sample gas. The sample gas may then pass through a second filter membrane. Liquids (e.g., moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized pharmaceutical solutions and suspensions, etc.) may be filtered out of the sample gas at the second filter membrane.

[0108] At block 904, the method includes collecting condensate from the sample gas in a filter device. The liquid filtered by the first filter membrane can be collected in a first reservoir located in a first chamber of the filter device. The first reservoir can also collect the saline solution blocked by the first filter membrane. The liquid filtered by the second filter membrane can be collected in a second reservoir located in a second chamber of the sample gas filter. The collected condensate can be maintained at a condensate pH of 5.0 to 6.0. Maintaining the condensate at a pH of 5.0 to 6.0 ensures that any salt or sodium from the saline solution is filtered before entering the water-permeable tubular membrane, thereby preventing any reaction in the water-permeable tubular membrane that may produce hydrochloric acid.

[0109] At block 906, the method includes passing the filtered sample gas through the water-permeable tubular membrane of the assembly. The sample gas exiting the water-permeable tubular membrane is humidity-regulated gas. The water-permeable tubular membrane may be housed in a vent cap connected to the sample gas filter. The vent cap may have at least one vent hole to allow ambient air to contact the water-permeable tubular membrane. When ambient air contacts the outer surface of the water-permeable tubular membrane, the water-permeable tubular membrane may release water vapor from the sample gas, thereby humidity-regulating the sample gas. The water-permeable tubular membrane regulates the humidity of the sample gas to the same as that of the ambient air.

[0110] The humidity conditioned gas may be substantially free of brine.The humidity conditioned gas may be 98%, 99%, 99.5% or 99.95% free of brine.

[0111] By filtering liquids (including saline solutions) before they reach the water-permeable tubular membrane, the generation of hydrochloric acid is prevented or reduced. Preventing or reducing the generation of hydrochloric acid can significantly reduce corrosion of the sample gas filter and corrosion of the therapeutic gas delivery device. Additionally, by preventing sodium from reacting with the water-permeable tubular membrane, blockage of the sample line, sample pump, and / or the water-permeable tubular membrane can be significantly reduced. With a 98% confidence level, blockage of the sample line connected to the assembly, blockage of the pump connected to the sample line, corrosion of the sample gas filter, and / or corrosion in the therapeutic gas delivery device can be reduced or prevented.

[0112] The method can include maintaining the pH of the condensate at about 5.0 to about 6.0. In another example, the assembly can maintain the pH of the condensate at about 5.3 to about 6.0. In another example, the assembly can maintain the pH of the condensate at about 5.4 to about 5.6.

[0113] At block 908, the method includes preventing the sample gas from contacting the sensor without first being humidity conditioned if the confidence level is 98%. The sample gas may be humidity conditioned through a water permeable tubular membrane. The sample gas may be humidity conditioned if the confidence level is 98%, 98.5%, 99%, 99.5%, 99.95%, or 99.99%.

[0114] Further provided herein is a method for preventing degradation or corrosion in a therapeutic gas delivery device. Figure 10 The flowchart shown is presented according to an example embodiment. The method is provided by way of example because there are many ways to perform the method. For example, the method 1000 described below can be performed using the illustrated configuration, and reference is made to the various elements in these figures when describing the example method 1000. Each box represents one or more processes, methods, or subroutines performed in the example method 1000. In addition, Figure 10 The order of the blocks shown in the figures is only illustrative, and the order of the blocks may be changed according to the present disclosure. Additional blocks may be added, or fewer blocks may be used without departing from the present disclosure.

[0115] Example method 1000 is a method for preventing degradation or corrosion in a therapeutic gas delivery device. The example method may begin at block 1002. At block 1002, the method includes passing a sample gas through a filter device (e.g., a sample gas filter) of an assembly. The sample gas may be provided to the filter device at a sample gas inlet. The sample gas may flow through the sample gas inlet to a first filter membrane. The first filter membrane may be hydrophobic and / or oleophobic. Liquids (e.g., moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized pharmaceutical solutions and suspensions, etc.) may be filtered out of the sample gas at the first filter membrane. The first filter membrane may also filter saline solution from the sample gas. The sample gas may then pass through a second filter membrane. Liquids (e.g., moisture, water vapor, moisture from humidified air, other liquids in a vapor state, aerosolized liquids, aerosolized pharmaceutical solutions and suspensions, etc.) may be filtered out of the sample gas at the second filter membrane.

[0116] At block 1004, the method includes collecting condensate from the sample gas in a filter device. Liquid filtered by the first filter membrane can be collected in a first reservoir located in a first chamber of the filter device. The first reservoir can also collect saline solution blocked by the first filter membrane. Liquid filtered by the second filter membrane can be collected in a second reservoir located in a second chamber of the sample gas filter.

[0117] At block 1006, the method includes passing the filtered sample gas through the water-permeable tubular membrane of the assembly. The sample gas exiting the water-permeable tubular membrane is humidity-regulated gas. The water-permeable tubular membrane may be housed in a vent cap connected to the sample gas filter. The vent cap may have at least one vent hole to allow ambient air to contact the water-permeable tubular membrane. When ambient air contacts the outer surface of the water-permeable tubular membrane, the water-permeable tubular membrane may release water vapor from the sample gas, thereby humidity-regulating the sample gas. The water-permeable tubular membrane regulates the humidity of the sample gas to the same as that of the ambient air.

[0118] The sample gas can be humidity conditioned with a confidence level of at least 98%, 99%, 99.5%, 99.9%, or 99.95%. The humidity conditioned gas can be substantially free of brine. The humidity conditioned gas can be 98%, 99%, 99.5%, or 99.95% free of brine.

[0119] At block 1008, the method includes maintaining the pH of the condensate at a 98% confidence level between about 5.0 and about 6.0. Maintaining the condensate at a pH of 5.0 to 6.0 ensures that any salt or sodium from the brine solution is filtered prior to entering the water permeable tubular membrane, thereby preventing any reaction in the water permeable tubular membrane that could produce hydrochloric acid.

[0120] In another example, the assembly can maintain the pH of the condensate at about 5.3 to about 6.0. In a further example, the assembly can maintain the pH of the condensate at about 5.4 to about 5.6.

[0121] By filtering liquids (including saline solutions) before they reach the water-permeable tubular membrane, the generation of hydrochloric acid is prevented or reduced. Preventing or reducing the generation of hydrochloric acid can significantly reduce corrosion of the sample gas filter and corrosion of the therapeutic gas delivery device. Additionally, by preventing sodium from reacting with the water-permeable tubular membrane, blockage of the sample line, sample pump, and / or the water-permeable tubular membrane can be significantly reduced. With a 98% confidence level, blockage of the sample line connected to the assembly, blockage of the pump connected to the sample line, corrosion of the sample gas filter, and / or corrosion in the therapeutic gas delivery device can be reduced or prevented.

[0122] The foregoing merely illustrates the principles of the present invention. Various modifications and variations to the described embodiments will be apparent to those skilled in the art based on the teachings herein. Therefore, it will be understood that those skilled in the art will be able to devise many systems, arrangements, and methods that, although not explicitly shown or described herein, embody the principles of the present invention and therefore fall within the spirit and scope of the present invention. From the foregoing description and accompanying drawings, it will be understood by those skilled in the art that the specific embodiments shown and described are for illustrative purposes only and are not intended to limit the scope of the present invention. Reference to specific embodiment details is not intended to limit the scope of the present invention.

[0123] Reference to an "embodiment," "aspect," "scenario," or "example" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Phrases appearing in various places throughout this specification in an "embodiment," "aspect," "scenario," or "example" do not necessarily all refer to the same embodiment, nor are separate embodiments or alternatives mutually exclusive of other embodiments. Furthermore, various features are described that may be exhibited by some embodiments but not others.

[0124] In the context of the present disclosure and in the specific context of using each term, the terms used in this specification sheet generally have their ordinary meaning in the art. For any one or more terms in the terms discussed herein, alternative language and synonyms can be used, and no matter whether the terms are described in detail or discussed in this article, special meanings should not be added. In some cases, synonyms for certain terms are provided. The detailed description of one or more synonyms does not exclude the use of other synonyms. The examples used anywhere in this specification sheet (including the examples of any terms discussed herein) are only illustrative, and are not intended to further limit the scope and meaning of the present disclosure or any example terms. Similarly, the present disclosure is not limited to the various embodiments provided in this specification sheet.

[0125] Examples

[0126] Table 1 shows the results of operating a therapeutic gas delivery device using different sample gas filter assembly configurations. Devices 6 and 10 are sample gas filter assemblies using the configurations described in the present disclosure above. Devices 6 and 10 consist of a sample gas line that provides sample gas to a sample gas inlet and a filter device that includes two filter membranes. The sample gas filter collects condensate, and the pH of the condensate is measured. The sample gas is then provided to the water-permeable tubular membrane through a sample gas outlet and a water-permeable tubular membrane inlet conduit. The sample gas flows through the water-permeable tubular membrane and is discharged at the assembly outlet. The sample gas then enters the gas sensor module of the therapeutic gas delivery device. Device 9 consists of another configuration of the sample gas filter assembly. The sample gas first flows through the water-permeable tubular membrane, then through the filter device, and then through the sample gas outlet to the therapeutic gas delivery device. The condensate is collected in the sample gas filter, and the pH of the condensate is measured. As shown in Table 1, by filtering the sample gas prior to humidity conditioning it in the water permeable tubular membrane, the generation of corrosive acids (pH 1-2) is reduced or prevented.

[0127] Table 1: Condensate pH results

[0128]

[0129]

[0130] Exemplary embodiments

[0131] The following is a list of exemplary embodiments, and various combinations thereof may be included.

[0132] Example 1: A filter assembly for a therapeutic gas delivery device, the assembly comprising: a filter device, the filter device comprising an inlet, an outlet, at least one fluid reservoir and at least one filter membrane, the at least one filter membrane being located between the inlet and the outlet, wherein the filter device is operable to remove water vapor from a sample gas and collect condensate in the at least one fluid reservoir; a water-permeable tubular membrane, the water-permeable tubular membrane being fluidly connected to the outlet of the filter device; and a vent cap connected to the filter device and surrounding the outlet, the vent cap comprising a vent hole.

[0133] Embodiment 2: The assembly of embodiment 1, wherein the water permeable tubular membrane is configured to humidity condition the sample gas.

[0134] Embodiment 3: The assembly of Embodiment 1, wherein the vent cap comprises a plurality of vent holes.

[0135] Embodiment 4: The assembly of Embodiment 1, wherein the vent cap is configured to receive and secure the water-permeable tubular membrane.

[0136] Embodiment 5: The assembly of embodiment 1, wherein the water permeable tubular membrane is formed from a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer.

[0137] Embodiment 6: The assembly of embodiment 1, wherein the water permeable tubular membrane is a pipe comprising a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer.

[0138] Example 7: An assembly according to Example 1, wherein the filter device comprises: a housing having a sample gas inlet and a sample gas outlet, the sample gas inlet being operable to receive sample gas from a sample line connected to an inhalation line of the therapeutic gas delivery device; a first filter membrane; and a first fluid reservoir, the first fluid reservoir being disposed between the sample gas inlet and the first filter membrane; and a second chamber, the second chamber being disposed in the housing, the second chamber comprising: a second filter membrane; and a second fluid reservoir, the second fluid reservoir being disposed between the first filter membrane and the sample gas outlet.

[0139] Embodiment 8: The assembly of Embodiment 7, wherein the first reservoir and the second reservoir are axially oriented such that the filter apparatus is operable for use in any axial orientation.

[0140] Embodiment 9: The assembly of Embodiment 7, wherein the housing, each of the chambers, and each of the filter membranes have substantially circular cross-sections.

[0141] Embodiment 10: The assembly of embodiment 1, wherein the at least one reservoir is large enough to hold water for 12 hours of continuous use.

[0142] Embodiment 11: The assembly of embodiment 1, wherein the at least one reservoir has a volume of at least 10 cubic centimeters.

[0143] Embodiment 12: The assembly of Embodiment 1, wherein the assembly is configured for one-handed installation in the therapeutic gas delivery device.

[0144] Example 13: A method for humidity regulating and filtering a sample gas in a therapeutic gas delivery device, the method comprising: passing the sample gas through a filter device of an assembly; collecting condensate from the sample gas in the filter device; and passing the filtered sample gas through a water-permeable tubular membrane of the assembly, wherein the sample gas exiting the water-permeable tubular membrane is humidity-regulated sample gas.

[0145] Embodiment 14: The method of embodiment 13, wherein the sample gas exiting the water permeable tubular membrane is humidity-conditioned sample gas at a confidence level of at least 98%.

[0146] Embodiment 15: The method of embodiment 13, wherein the sample gas exiting the water permeable tubular membrane is a humidity-conditioned sample gas at a confidence level of at least 99%.

[0147] Embodiment 16: The method of embodiment 13, wherein the sample gas exiting the water permeable tubular membrane is humidity conditioned sample gas with a confidence level of at least 99.5%.

[0148] Embodiment 17: The method of embodiment 13, wherein the sample gas exiting the water permeable tubular membrane is humidity conditioned sample gas with a confidence level of at least 99.9%.

[0149] Embodiment 18: The method of embodiment 13, wherein the sample gas exiting the water permeable tubular membrane is humidity conditioned sample gas with a confidence level of at least 99.95%.

[0150] Embodiment 19: The method of embodiment 13, further comprising exposing the outer surface of the water permeable tubular membrane to an ambient air flow.

[0151] Embodiment 20: The method of embodiment 13, wherein the humidity-conditioned sample gas is substantially free of saline.

[0152] Embodiment 21: The method of embodiment 13, further comprising reducing or preventing the generation of HCl within the therapeutic gas delivery device.

[0153] Example 22: The method of Example 13, further comprising reducing or preventing blockage of a sample line connected to the assembly, blockage of a pump connected to the sample line, corrosion of the filter device, and / or corrosion in the therapeutic gas delivery device with a confidence level of at least 98%.

[0154] Embodiment 23: The method of embodiment 13, wherein the assembly maintains the pH of the condensate at about 5.0 to about 6.0.

[0155] Embodiment 24: The method of embodiment 13, wherein the assembly maintains the pH of the condensate at about 5.3 to about 6.0.

[0156] Embodiment 25. The method of embodiment 13, wherein the assembly maintains the pH of the condensate at about 5.4 to about 5.6.

[0157] Example 26: A method for maintaining the pH of condensate from an assembly for humidity regulating and filtering a sample gas in a therapeutic gas delivery device, the method comprising: passing the sample gas through a filter device of the assembly; collecting condensate from the sample gas in the filter device; and passing the filtered sample gas through a water-permeable tubular membrane of the assembly, wherein the sample gas exiting the water-permeable tubular membrane is humidity-regulated sample gas, wherein the assembly maintains the pH of the condensate between 5.0 and 6.0.

[0158] Embodiment 27: The method of Embodiment 26, wherein the humidity-conditioned sample gas is substantially free of saline.

[0159] Embodiment 28: The method of embodiment 26, further comprising exposing the outer surface of the water permeable tubular membrane to an ambient air flow.

[0160] Embodiment 29: The method of Embodiment 26, wherein the assembly reduces or prevents the generation of HCl within the therapeutic gas delivery device.

[0161] Embodiment 30: The method of Embodiment 26, wherein the assembly reduces or prevents clogging of a sample line connected to the assembly, clogging of a pump connected to the sample line, corrosion of the filter device, or corrosion in the therapeutic gas delivery apparatus.

[0162] Example 31: A method for preventing degradation or corrosion in a therapeutic gas delivery device, the method comprising: passing a sample gas through a filter device of an assembly; collecting condensate from the sample gas in the filter device; passing the filtered sample gas through a water-permeable tubular membrane of the assembly, wherein the sample gas exiting the water-permeable tubular membrane is humidity-conditioned sample gas; and preventing the sample gas from contacting a sensor without first being humidity-conditioned with a confidence level of at least 98%.

[0163] Example 32: A method for preventing degradation or corrosion in a therapeutic gas delivery device, the method comprising: passing a sample gas through a filter device of an assembly; collecting condensate from the sample gas in the filter device; passing the filtered sample gas through a water-permeable tubular membrane of the assembly, wherein the sample gas exiting the water-permeable tubular membrane is humidity-adjusted sample gas; and maintaining the pH of the condensate at a confidence level of at least 98% at a range of about 5.0 to about 6.

[0164] Although several embodiments have been described, it will be appreciated by those skilled in the art that various modifications, alternative configurations, and equivalents may be used without departing from the spirit of the present invention. Additionally, many well-known processes and elements have not been described in order to avoid unnecessarily obscuring the present invention. Therefore, the above description should not be construed as limiting the scope of the present invention.

[0165] Those skilled in the art will appreciate that the presently disclosed embodiments teach by way of example and not limitation. Accordingly, everything contained in the foregoing description or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover all generic and specific features described herein and all statements of the scope of the present systems and methods that can be said to fall therein.

Claims

1. A filter assembly for a therapeutic gas delivery device, the assembly comprising: a filter device comprising an inlet, an outlet, and at least one reservoir and at least one filter membrane positioned between the inlet and the outlet, wherein the filter device is operable to remove water vapor from the sample gas and collect condensate in the at least one reservoir; a water permeable tubular membrane fluidly connected to the outlet of the filter device; and A vent cap is connected to the filter device and surrounds the outlet, the vent cap including a vent hole.

2. The assembly of claim 1, wherein the water permeable tubular membrane is configured to humidity condition the sample gas.

3. The assembly of claim 1, wherein the vent cap includes a plurality of vent holes.

4. The assembly of claim 1, wherein the cowl is configured to receive and secure the water-permeable tubular membrane.

5. The assembly of claim 1 wherein the water permeable tubular membrane is formed from a sulfonated tetrafluoroethylene based fluoropolymer-copolymer.

6. The assembly of claim 1 wherein the water permeable tubular membrane is a pipe comprising a sulfonated tetrafluoroethylene based fluoropolymer-copolymer.

7. The assembly of claim 1 , wherein the filter device comprises: a housing having a sample gas inlet and a sample gas outlet, the sample gas inlet being operable to receive sample gas from a sample line connected to an inhalation line of the therapeutic gas delivery device; A first chamber is disposed in the housing, and the first chamber comprises: a first filter membrane; as well as a first liquid storage tank, the first liquid storage tank being disposed between the sample gas inlet and the first filter membrane; and A second chamber is disposed in the housing, the second chamber comprising: a second filter membrane; as well as A second liquid storage tank is provided between the first filter membrane and the sample gas outlet.

8. The assembly of claim 7, wherein the first and second reservoirs are axially oriented such that the filter apparatus is operable for use in any axial orientation.

9. The assembly of claim 7, wherein the housing, each of the chambers, and each of the filter membranes have a substantially circular cross-section.

10. The assembly of claim 1, wherein the at least one reservoir is large enough to hold water for 12 hours of continuous use.

11. The assembly of claim 1 , wherein the at least one reservoir has a volume of at least 10 cubic centimeters.

12. The assembly of claim 1, wherein the assembly is configured for one-handed installation in the therapeutic gas delivery device.

13. A method for humidity conditioning and filtering a sample gas in a therapeutic gas delivery device, the method comprising: passing the sample gas through a filter device of the assembly; collecting condensate from the sample gas in the filter device; and Passing filtered sample gas through the water permeable tubular membrane of the assembly, wherein the sample gas exiting the water permeable tubular membrane is humidity-conditioned sample gas.

14. The method of claim 13, wherein the sample gas exiting the water permeable tubular membrane is humidity conditioned sample gas with a confidence level of at least 98%.

15. The method of claim 13, wherein the sample gas exiting the water permeable tubular membrane is humidity conditioned sample gas with a confidence level of at least 99%.

16. The method of claim 13, wherein the sample gas exiting the water permeable tubular membrane is humidity conditioned sample gas with a confidence level of at least 99.5%.

17. The method of claim 13, wherein the sample gas exiting the water permeable tubular membrane is humidity conditioned sample gas with a confidence level of at least 99.9%.

18. The method of claim 13, wherein the sample gas exiting the water permeable tubular membrane is humidity conditioned sample gas with a confidence level of at least 99.95%.

19. The method of claim 13, further comprising exposing an outer surface of the water permeable tubular membrane to an ambient air flow.

20. The method of claim 13, wherein the humidity-conditioned sample gas is substantially free of saline.

21. The method of claim 13, further comprising reducing or preventing the generation of HCl within the therapeutic gas delivery device.

22. The method of claim 13, further comprising reducing or preventing, with a confidence level of at least 98%, blockage of a sample line connected to the assembly, blockage of a pump connected to the sample line, corrosion of the filter apparatus, and / or corrosion in the therapeutic gas delivery device.

23. The method of claim 13, wherein the assembly maintains the pH of the condensate at about 5.0 to about 6.

0.

24. The method of claim 13, wherein the assembly maintains the pH of the condensate at about 5.3 to about 6.

0.

25. The method of claim 13, wherein the assembly maintains the pH of the condensate at about 5.4 to about 5.

6.

26. A method of maintaining condensate pH from an assembly for humidity conditioning and filtering a sample gas in a therapeutic gas delivery device, the method comprising: passing the sample gas through a filter device of the assembly; collecting condensate from the sample gas in the filter device; and passing a filtered sample gas through a water permeable tubular membrane of the assembly, wherein the sample gas exiting the water permeable tubular membrane is a humidity conditioned sample gas, wherein the assembly maintains the pH of the condensate between 5.0 and 6.

0.

27. The method of claim 26, wherein the humidity-conditioned sample gas is substantially free of brine.

28. The method of claim 26, further comprising exposing an outer surface of the water permeable tubular membrane to an ambient air flow.

29. The method of claim 26, wherein the assembly reduces or prevents the generation of HCl within the therapeutic gas delivery device.

30. The method of claim 26, wherein the assembly reduces or prevents clogging of a sample line connected to the assembly, clogging of a pump connected to the sample line, corrosion of the filter device, or corrosion in the therapeutic gas delivery apparatus.

31. A method for preventing degradation or corrosion in a therapeutic gas delivery device, the method comprising: a filter device for passing the sample gas through the assembly; collecting condensate from the sample gas in the filter device; passing a filtered sample gas through the water permeable tubular membrane of the assembly, wherein the sample gas exiting the water permeable tubular membrane is a humidity-conditioned sample gas; and With a confidence level of at least 98%, the sample gas is prevented from contacting the sensor without first being humidity conditioned.

32. A method for preventing degradation or corrosion in a therapeutic gas delivery device, the method comprising: a filter device for passing the sample gas through the assembly; collecting condensate from the sample gas in the filter device; passing a filtered sample gas through the water permeable tubular membrane of the assembly, wherein the sample gas exiting the water permeable tubular membrane is a humidity-conditioned sample gas; and With a confidence level of at least 98%, the pH of the condensate is maintained at a range of about 5.0 to about 6.

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