Patent Publication Number: US-2023149627-A1

Title: Modular intravenous assembly

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This is a continuation of patent application Ser. No. 16/886,388, filed on May 28, 2020, entitled “MODULAR INTRAVENOUS ASSEMBLY,” the contents of which is hereby incorporated by reference in its entirety, for all purposes. 
    
    
     BACKGROUND 
     Intravenous (IV) infusion sets typically include several components each having a core function, such as drip chambers, roller clamps, pinch clamps, filters and check valves. These components are typically coupled to each other by lengths of IV tubing to provide a complete IV infusion set that is packaged as a ready to use disposable IV set. Such an IV infusion set has a significant number of IV tubing connections, which provides a correspondingly increased risk of connection leakage as the number of IV tubing connections grows larger. Each separate component also provides a different interface point to a user. These factors lead to higher manufacturing complexity and costs. 
     It is desirable to provide a modular IV assembly that combines many IV component core functions into one device, thus reducing manufacturing complexity and costs, as well as improving usability by the user. 
     SUMMARY 
     The present disclosure provides modular IV assemblies that combine core functions of several IV infusion set components. 
     In one or more embodiments, a modular intravenous (IV) assembly is provided. The modular IV assembly includes a drip chamber having a body and an inlet connector. The modular IV assembly also includes a base housing coupled directly to a base portion of the drip chamber, the base housing having an inlet port in fluid connection with the drip chamber and a flow path cavity in fluid connection with the inlet port. The modular IV assembly further includes a flow control assembly coupled directly to a first portion of the base housing. The flow control assembly includes a roller housing, a roller and a flow control membrane disposed between the roller and the flow path cavity in the base housing. 
     In one or more aspects, the flow path cavity comprises a first flow area having a constant width and a varying depth, and a second flow area having a varying width and a constant depth. In one or more aspects, the flow control assembly is configured to prevent fluid flow through the base housing when the roller is engaged with the flow control membrane adjacent to a start position of the first flow area. In one or more aspects, the flow control assembly is configured to provide full fluid flow through the base housing when the roller is engaged with the flow control membrane adjacent to an end portion of the second flow area. In one or more aspects, the flow control assembly is configured to provide increasing fluid flow through the base housing as the roller engaged with the flow control membrane moves from an end portion of the second flow area. 
     In one or more aspects, a filter assembly is coupled directly to a second portion of the base housing. In one or more aspects, the first and second portions are on opposing surfaces of the base housing. In one or more aspects, the filter assembly includes a filter housing coupled directly to the second portion of the base housing and a filter membrane disposed between the filter housing and the second portion of the base housing. In one or more aspects, the filter membrane comprises a hydrophilic material that prevents gas from passing through the filter membrane when the filter membrane is wetted. In one or more aspects, a first surface of the filter membrane is disposed adjacently at a distance from an inner surface of the second portion of the base housing, and wherein a space between the inner surface of the second portion and the first surface of the filter membrane is configured to provide a flow path for fluid entering the second portion of the base housing from the flow control assembly. In one or more aspects, a second surface of the filter membrane is disposed adjacently at a distance from an inner surface of the filter housing, and wherein a space between the inner surface of the filter housing and the second surface of the filter membrane is configured to provide a flow path for fluid passing through the filter membrane. 
     In one or more aspects, an anti-run dry member including one of an individual layer disposed on the filter membrane and an integrally formed material comprising the filter membrane is included. In one or more aspects, a filter housing coupled directly to the second portion of the base housing, a fluid exit housing coupled directly to the filter housing and a one-way check valve disposed between an exit cavity in an outer surface of the filter housing and the fluid exit housing, the check valve configured to allow fluid to flow out from the exit cavity through an exit port in the fluid exit housing while preventing fluid from flowing in the opposing direction into the exit cavity. In one or more aspects, the fluid exit housing, the check valve and the exit cavity are disposed at a top portion of the base housing adjacent to the drip chamber. In one or more aspects, the fluid exit housing, the check valve and the exit cavity are disposed at a bottom portion of the base housing. 
     In one or more aspects, an air vent assembly is coupled directly to a second portion of the base housing, wherein the first and second portions are on opposing surfaces of the base housing, the air vent assembly including a vent cavity disposed in the second portion of the base housing, a vent port disposed in the vent cavity, the vent port coupled to an air flow path in the base housing and an air vent membrane disposed in the vent cavity. In one or more aspects, the air vent membrane comprises a small pore hydrophobic material that prevents liquid from passing through the air vent membrane into the vent port while allowing gas to pass through the air vent membrane and vent out through the vent port. In one or more aspects, the drip chamber includes a self-leveling assembly having a bottom housing portion disposed at the base portion of the drip chamber and adjacent to the base housing, a leveling outlet port aligned with the inlet port in the base housing, first and second leveling inlet ports disposed adjacent opposing sides of the leveling outlet port and a barrier disposed within the first leveling inlet port. 
     In one or more embodiments, an intravenous (IV) set is provided. The IV set includes a modular IV assembly having a drip chamber with a body and an inlet connector, a base housing coupled directly to a base portion of the drip chamber, the base housing having an inlet port in fluid connection with the drip chamber and a flow path cavity in fluid connection with the inlet port and a flow control assembly coupled directly to a first portion of the base housing, the flow control assembly including a roller housing, a roller and a flow control membrane disposed between the roller and the flow path cavity in the base housing. The IV set also includes a fluid container coupled to the inlet connector of the drip chamber by a first IV tube. The IV set further includes a fluid delivery member coupled to the modular IV assembly by a second IV tube. 
     In one or more embodiments, a method of delivering a medical fluid is provided. The method includes coupling a fluid container to a modular intravenous (IV) assembly with a first IV tube, the modular IV assembly including a drip chamber having a body and an inlet connector, a base housing coupled directly to a base portion of the drip chamber, the base housing having an inlet port in fluid connection with the drip chamber and a flow path cavity in fluid connection with the inlet port and a flow control assembly coupled directly to a first portion of the base housing, the flow control assembly including a roller housing, a roller and a flow control membrane disposed between the roller and the flow path cavity in the base housing. The method also includes coupling a fluid delivery member to the modular IV assembly with a second IV tube. The method further includes adjusting a fluid flow rate from the modular IV assembly to the fluid delivery member by moving the roller in the flow control assembly. 
     Additional features and advantages of the disclosure will be set forth in the description below and, in part, will be apparent from the description or may be learned by practice of the disclosure. The objectives and other advantages of the disclosure will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the disclosure as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the principles of the disclosure. 
         FIG.  1    depicts a schematic view of a typical assembled infusion set. 
         FIG.  2    is a perspective view of a modular IV assembly, according to some aspects of the disclosure. 
         FIG.  3    is another perspective view of the modular IV assembly of  FIG.  2   , according to some aspects of the disclosure. 
         FIG.  4    is a front view of the modular IV assembly of  FIG.  2   , according to some aspects of the disclosure. 
         FIG.  5    is an exploded perspective view of the modular IV assembly of  FIG.  2   , according to some aspects of the disclosure 
         FIG.  6    is a cross-sectional side view of the modular IV assembly of  FIG.  2   , according to some aspects of the disclosure. 
         FIG.  7    is an enlarged partial view of the modular IV assembly of  FIG.  6   , according to some aspects of the disclosure. 
         FIG.  8    is a cross-sectional side view of a modular IV assembly, according to some aspects of the disclosure. 
         FIG.  9    is a cross-sectional side view of a modular IV assembly, according to some aspects of the disclosure. 
         FIG.  10    is a cross-sectional side view of a modular IV assembly, according to some aspects of the disclosure. 
         FIG.  11    is a front view of a base housing of a modular IV assembly, according to some aspects of the disclosure. 
         FIG.  12    is a partial perspective view of the base housing of  FIG.  11   , according to some aspects of the disclosure. 
         FIG.  13    is a partial perspective view of a flow control assembly of a modular IV assembly, according to some aspects of the disclosure. 
         FIG.  14    is a graph depicting a variation in flow area based on the flow control assembly of  FIG.  13   . 
         FIG.  15    is a partial perspective view of a modular IV assembly, according to some aspects of the disclosure. 
         FIG.  16    is an exploded perspective view of the modular IV assembly of  FIG.  15   , according to some aspects of the disclosure. 
         FIG.  17    is a front view of a portion of an air vent assembly of a modular IV assembly, according to some aspects of the disclosure. 
         FIG.  18    is a front view of a drip chamber of a modular IV assembly, according to some aspects of the disclosure. 
         FIG.  19    is a front view of a self-leveling assembly of the drip chamber of  FIG.  18   , according to some aspects of the disclosure. 
         FIGS.  20 - 22    are schematic views depicting the operation of the self-leveling assembly of  FIG.  19   . 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below describes various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. Accordingly, dimensions are provided in regard to certain aspects as non-limiting examples. However, it will be apparent to those skilled in the art that the subject technology may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology. 
     It is to be understood that the present disclosure includes examples of the subject technology and does not limit the scope of the appended claims. Various aspects of the subject technology will now be disclosed according to particular but non-limiting examples. Various embodiments described in the present disclosure may be carried out in different ways and variations, and in accordance with a desired application or implementation. 
     IV infusion sets may be formed from any combination of infusion components and tubing. Typically, the infusion components and tubing are disposable products that are used once and then discarded. The infusion components and tubing may be formed from any suitable material (e.g., plastic, silicone, rubber). An issue in manufacturing IV infusion sets is joining multiple tubing and the infusion components to obtain secure leak free joints with desired fluid flow. An issue in using IV infusion sets is that having many separate components provides many interface points to a user. 
     As shown in  FIG.  1   , a typical infusion set  30  may include a drip chamber  40 , a check valve  50 , a roller clamp  60  and Y-junctions  70 , all connected together by tubing  20 . A typical infusion set  30  can include additional infusion components (e.g., pinch clamps, filters) and can be formed of any combination of components and the tubing  20 . 
     According to some aspects of the disclosure, a modular IV assembly combines IV component core functions into one device, thus reducing the number of tubing connections required for an IV infusion set. According to some aspects of the disclosure, the modular IV assembly provides a design architecture that can be more easily automated than a convention IV infusion set. 
     According to some aspects of the disclosure, the modular IV assembly provides a design architecture that easily provides for substitutions and replacements of core function elements during the manufacturing process. According to some aspects of the disclosure, the modular IV assembly provides a single interface point to the user. 
     A modular IV assembly  100  is shown in  FIGS.  2 - 10   , according to some aspects of the disclosure. The modular IV assembly  100  includes a drip chamber  110 , a flow control assembly  120 , a filter assembly  130 , an air vent assembly  140  (e.g., for a fluid path), an anti-run dry (ARD) member  150  and a check valve  160 . Thus, the modular IV assembly provides one device that includes many different features, such as anti-run dry fluid flow, drop visibility, flow control, fluid filtering, air venting (e.g., line de-bubbling) and flow direction control from the check valve. The modular IV assembly  100  may have a large area below the drip chamber  110 , thus providing an area for a user to grip easily. 
     The drip chamber  110  has a body  112  formed of a material suitable for use in infusion procedures. For example, the body  112  may be formed of a hard plastic that is not squeezable and thus also has an auto prime function. As another example, the body  112  may be formed of a flexible plastic that is squeezable and thus does not require an auto prime function. The body  112  may be transparent to provide drip visibility from the fluid entering the drip chamber  110 . The drip chamber  110  is coupled to a base housing  170 . For example, the body  112  may be an elongated cylinder having a base portion  113  that is coupled to a drip chamber coupling portion  172  of the base housing  170 . The drip chamber coupling portion  172  includes an inlet port  173  that provides a fluid pathway from the drip chamber  110  into the base housing  170  (see  FIGS.  6  and  7   ). Any size and shape is contemplated for the drip chamber  110  and correspondingly the drip chamber coupling portion  172 . An inlet connector  114  is coupled to the body  112 . The inlet connector  114  may be configured to receive an IV tube from a fluid source (e.g., IV bag), for example. As another example, the inlet connector  114  may be configured to connect directly to an IV fluid container (e.g., bag, bottle) via a spike connection. 
     The flow control assembly  120  is coupled to the base housing  170 . The flow control assembly  120  includes a roller housing  122 , a roller  124 , and a flow control membrane  126 . The roller housing  122  is sized and shaped to couple with the base housing  170 . The roller  124  is movably coupled to the roller housing  122 . For example, axles  125  of the roller  124  may be received within channels  123  disposed on opposing walls of the roller housing  122 , where the axles  125  move axially along the channels  123  when the roller  124  is moved. The flow control membrane  126  is sized and shaped to be received within the base housing  170 . The flow control membrane  126  may be formed of a flexible material (e.g., elastomer), such that flow control membrane  126  may flex into a fluid flow path  174  when the roller  124  engages the flow control membrane  126 . In some aspects of the disclosure, the flow control assembly may include a different control member than the roller  124 , such as a lever, a slider or a knob, for example. 
     As shown in  FIGS.  11 - 13   , the base housing  170  may be formed of a hard plastic, where the fluid flow path  174  is formed by a cavity  176  disposed within a surface of the base housing  170 . The cavity  176  may vary in both width and depth to provide different fluid flow rates based on the position of the roller  124 . For example, the cavity  176  shown in  FIG.  12    has a first section  174   a  having a length L 1  of 15 mm and a width A of 0.75 mm, and a second section  174   b  having a length L 2  of 15 mm and a width C of 2.5 mm. The depth of first section  174   a  increases from zero at one end to depth B of 0.5 mm at the other end. The depth of the second section  174   b  is a constant depth B of 0.5 mm. Any of the widths A and C, depth B and lengths L 1  and L 2  may be independently varied to tune the cavity  176 , and therefore the fluid flow path  174 , for a specific flow profile. 
     As shown in  FIG.  13   , the portion of the roller  124  that engages the flow control membrane  126  causes the flow control membrane  126  to flex into the cavity  176 , which blocks the fluid flow path  174  to varying degrees based on the position of the engaged portion of the roller  124  over the cavity  176 .  FIG.  14    shows a graph  1400  depicting the variation in flow area over the travel length of the roller  124  based on the above described values for A, B, C, L 1  and L 2 . The flow area under the portion of the roller  124  that engages the flow control membrane  126  corresponds to a resulting fluid flow rate through the cavity  176 , with the largest flow area providing a greater fluid flow rate and the smallest flow area providing a lesser fluid flow rate. 
     For example, when the roller  124  is positioned at the end of L 1  with a depth of zero, the flow area is zero and the fluid flow path  174  is completely occluded (e.g., no fluid flow through the fluid flow path  174 ). When the roller  124  is positioned at the junction of the second end of L 1  and the first end of L 2 , the fluid flow area is 0.375 mm 2  and the fluid flow path  174  is partially occluded, thus providing for a 30% fluid flow rate. When the roller  124  is positioned at the second end of L 2 , the fluid flow area is 1.25 mm 2  and the fluid flow path  174  is not occluded, thus providing for a 100% fluid flow rate (e.g., full open). As shown in  FIG.  14   , the first portion of the graph corresponding to the roller  124  engagement along length L 1  indicates a fine adjustment portion of the flow control assembly  120 , while the portion of the graph corresponding to the roller  124  engagement along the length L 2  indicates a gross adjustment portion of the flow control assembly  120 . According to some aspects of the disclosure, any number of flow variation areas may be provided, such as three or more, for example. Thus, there may be correspondingly more cavity sections than the first and second sections  174   a ,  174   b , such as three or more cavity sections, for example. 
     Since the drip chamber  110  is coupled directly to the base housing  170 , no IV tubing is necessary to link the drip chamber to the flow control assembly  120 , as opposed to the infusion set  30  shown in  FIG.  1    for which the drip chamber  40  and the roller clamp  60  are each coupled within the infusion set  30  via tubing  20 . Further, since the flow control assembly  120  does not include or engage with flexible IV tubing, the fluid flow rate can be consistently provided and maintained through the life of the modular IV assembly  100 . For example, the hard plastic of the base housing  170  does not deform (e.g., drift) over time. By contrast, a typical roller clamp  60  involves restricting fluid flow within soft, flexible tubing  20  by deforming the tubing  20 , and the tubing  20  tends to relax (e.g., lose its resilience) over time, which makes it increasingly difficult to precisely control the fluid flow rate over time. Accordingly, the flow control assembly  120  is configured to provide consistent and precise control of the fluid flow rate through the modular IV assembly  100 . 
     As shown in  FIGS.  15 - 17   , the base housing  170  is also configured to couple with a filter assembly  130  on an opposing side of the base housing  170  from the flow control assembly  120 . The filter assembly  130  includes a filter housing  132  that engages and traps a filter membrane  134  against the base housing  170 . The filter membrane  134  is formed from a hydrophilic material that prevents air from passing through the filter membrane  134  once the filter membrane  134  is wetted. Thus, only liquid may pass through the filter membrane  134  from the base housing  170 . The filter membrane  134  material may be designed or chosen for specific filtering properties in order to filter out particular elements from the fluid passing through the filter assembly  130 . For example, the filter membrane  134  may be formed to filter out particles larger than a particular size (e.g., 15 um, 5 um, 1.2 um, 0.2 um). 
     The base housing  170  also includes a portion on the same side as the filter assembly  130  on which the air vent assembly  140  is disposed. The air vent assembly  140  includes vent ports  142  in a vent cavity  146  in the base housing  170  and an air vent membrane  144  disposed in the vent cavity  146  over the vent ports  142 . The air vent membrane  144  is formed from a small pore hydrophobic material that prevents liquid from passing through the air vent membrane  144  while allowing gas (e.g., air) to vent out of the fluid flow path  174  through the vent ports  142  (e.g., back into the drip chamber  110 ). 
     The ARD member  150  is shown in  FIG.  5    as being integral with the filter membrane  134 . For example, the filter membrane  134  material may be designed or chosen to provide ARD features as well as filtering features. In some aspects of the disclosure, the ARD member  150  may be an ARD material and the filter membrane  134  may be a different filtering material combined together (e.g., separate layers, integrally formed) into one membrane with both filtering and ARD properties. 
     As shown in  FIG.  5   , the check valve  160  is disposed between an exit cavity  162  on the outer surface of the filter housing  132  and a fluid exit housing  180 . The check valve  160  may be formed from a flexible material and act as a one-way valve that allows fluid to flow from a fluid port  164  in the exit cavity  162  out through an exit port  182  in the fluid exit housing  180 , while preventing fluid flow in the opposing direction from the exit port  182  to the fluid port  164 . The fluid exit housing  180  also includes an outlet port  184  configured to be coupled to IV tubing, such as IV tubing connected to an infusion pump or a catheter, for example. The check valve  160  and fluid exit housing  180  may be disposed at the top end of the base housing  170  as shown in  FIG.  5   , or at the bottom or base portion of the base housing  170  as shown in  FIGS.  8  and  9   . 
     In operation, as shown in  FIG.  7   , the modular IV assembly  100  provides a fluid flow path  174  that begins upon entry of fluid from the drip chamber  110  and ends upon exit of fluid from the exit port  182 . The fluid flow path  174  includes flow of fluid through the flow control assembly  120  at a flow rate set by the position of the roller  124  in relation to the cavity  176 . The fluid exits the cavity  176  and flows into contact with the filter membrane  134  and ARD member  150 . The fluid is filtered through the filter membrane  134  and exits into the filter housing  132  and out through the fluid port  164 . The fluid then flows past and/or through the check valve  160  and out through the exit port  182  to the outlet port  184 . Since air trapped in the fluid cannot pass through the filter membrane  134 , the air instead passes through the air vent membrane  144  into the vent ports  142  and out of the base housing  170  portion of the modular IV assembly  100 . 
     As shown in  FIGS.  8 - 10   , the modular IV assembly  100  may be configured to include any or all of the above described components while maintaining the same or similar outward package and appearance. For example,  FIG.  8    depicts a base modular IV assembly  100  including the drip chamber  110  and the flow control assembly  120  only, with no filter assembly  130 , air vent assembly  140 , ARD member  150  or check valve  160 . Here, fluid flows into the base housing  170  from the drip chamber  110  and flows out the outlet port  184  at a flow rate set by the flow control assembly  120 .  FIG.  9    depicts a more integrated modular IV assembly  100  by adding the check valve  160  to the base modular IV assembly  100  shown in  FIG.  8   . Similarly,  FIG.  10    depicts an even more integrated modular IV assembly  100  by adding a filter membrane  134  and an ARD member  150  to the modular IV assembly  100  shown in  FIG.  9   . The air vent membrane  144  may further be added to any of the above-described modular IV assemblies  100 . Accordingly, the exterior of any modular IV assembly  100  may be defined by the drip chamber  110 , the roller housing  122 , the base housing  170 , the filter housing  132  and the fluid exit housing  180 . Here, the external form of modular IV assembly  100  package may remain constant regardless of the presence of absence of the internal components (e.g., filter assembly  130 , air vent assembly  140 , ARD member  150 , check valve  160 ). 
     As shown in  FIGS.  18 - 22   , the drip chamber  110  may include a self-leveling assembly  190 , according to aspects of the disclosure. The body  112  of the drip chamber  110  may act as both an air trap and a drop visibility chamber. The self-leveling assembly  190  has a top housing portion  191  and a bottom housing portion  193 , where the bottom housing portion  193  may be disposed at the base portion  113  of the body  112 . The self-leveling assembly  190  includes a leveling outlet port  192  that is aligned with the inlet port  173  in the drip chamber coupling portion  172  of the base housing  170 . The self-leveling assembly  190  also includes leveling fluid inlets  194 ,  196  disposed adjacent to the leveling outlet port  192 . Here, the leveling fluid inlet  194  has a shortened flow path and is disposed near the top housing portion  191  (e.g., away from the base portion  113 ), while the leveling fluid inlet  196  has a lengthened flow path and is disposed near the bottom housing portion  193  (e.g., close to the base portion  113 ). A barrier  198  (e.g., hydrophilic membrane, air check valve) is disposed within the leveling fluid inlet  194 . 
     As shown in  FIG.  20   , when the liquid level in the drip chamber  110  covers leveling fluid inlet  196  and does not cover leveling fluid inlet  194 , air trapped in the body  112  is vented out through the leveling outlet port  192 . As shown in  FIG.  21   , when the liquid level in the drip chamber  110  rises to cover both leveling fluid inlet  196  and leveling fluid inlet  194 , the barrier  198  prevents air from passing through and subsequently only liquid (e.g., saline solution) passes out through the leveling outlet port  192 . Here, liquid can freely enter/pass through leveling fluid inlet  196  and may also enter/pass through leveling fluid inlet  194  at a slower rate due to the barrier  198 . As shown in  FIG.  22   , when enough liquid siphons out through the leveling outlet port  192  that the leveling fluid inlet  194  is again exposed to air in the body  112 , the liquid continues to enter/pass through the leveling fluid inlet  196  only while the air is blocked from passing through the barrier  198 . 
     For example, the barrier  198  may be a membrane formed from a hydrophilic material that prevents air from passing through the barrier  198  once the barrier  198  is wetted. Thus, in  FIG.  20    the barrier  198  is not yet wetted, so air may pass through and exit the leveling outlet port  192 . Once the barrier  198  is wetted in  FIG.  21   , the barrier  198  prevents air from passing through. When the liquid recedes from the barrier  198  in  FIG.  22   , the barrier  198  is still wetted and thus continues to prevent air from passing through until it dries out. 
     As another example, the barrier  198  may be an air check valve that allows air to pass through the barrier  198  while preventing liquid from passing through the barrier  198 . Thus, in  FIG.  20    the barrier  198  is open to the air in the body  112 , so air may pass through and exit the leveling outlet port  192 . Once the barrier  198  is submerged under the liquid level in  FIG.  21   , the barrier  198  prevents liquid from passing through leveling fluid inlet  194  and thus the liquid only enters/passes through leveling fluid inlet  196  and out the leveling outlet port  192 . When the liquid recedes from the barrier  198  in  FIG.  22   , the pressure exerted by the liquid trapped above the barrier  198  within the self-leveling assembly  190  may prevent air from passing through the barrier  198  while liquid continues to enter/pass through the leveling fluid inlet  196  and out the leveling outlet port  192 . 
     The self-leveling assembly  190  eliminates the need to prime the drip chamber  110  by squeezing a flexible body  112  to push air out and to allow fluid to enter through the inlet connector  114 . Thus, the self-leveling assembly  190  provides for venting air from the drip chamber  110  regardless of whether the body  112  is flexible (e.g., flexible plastic) or stiff (e.g., hard plastic). Further, the self-leveling assembly  190  may prevent microbubbles from entering the fluid. 
     It is understood that any specific order or hierarchy of blocks in the methods of processes disclosed is an illustration of example approaches. Based upon design or implementation preferences, it is understood that the specific order or hierarchy of blocks in the processes may be rearranged, or that all illustrated blocks be performed. In some implementations, any of the blocks may be performed simultaneously. 
     The present disclosure is provided to enable any person skilled in the art to practice the various aspects described herein. The disclosure provides various examples of the subject technology, and the subject technology is not limited to these examples. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. 
     A reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the invention. 
     The word “exemplary” is used herein to mean “serving as an example or illustration.” Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. In one aspect, various alternative configurations and operations described herein may be considered to be at least equivalent. 
     As used herein, the phrase “at least one of” preceding a series of items, with the term “or” to separate any of the items, modifies the list as a whole, rather than each item of the list. The phrase “at least one of” does not require selection of at least one item; rather, the phrase allows a meaning that includes at least one of any one of the items, and/or at least one of any combination of the items, and/or at least one of each of the items. By way of example, the phrase “at least one of A, B, or C” may refer to: only A, only B, or only C; or any combination of A, B, and C. 
     A phrase such as an “aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. An aspect may provide one or more examples. A phrase such as an aspect may refer to one or more aspects and vice versa. A phrase such as an “embodiment” does not imply that such embodiment is essential to the subject technology or that such embodiment applies to all configurations of the subject technology. A disclosure relating to an embodiment may apply to all embodiments, or one or more embodiments. An embodiment may provide one or more examples. A phrase such an embodiment may refer to one or more embodiments and vice versa. A phrase such as a “configuration” does not imply that such configuration is essential to the subject technology or that such configuration applies to all configurations of the subject technology. A disclosure relating to a configuration may apply to all configurations, or one or more configurations. A configuration may provide one or more examples. A phrase such a configuration may refer to one or more configurations and vice versa. 
     In one aspect, unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. In one aspect, they are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain. 
     It is understood that the specific order or hierarchy of steps, operations or processes disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps, operations or processes may be rearranged. Some of the steps, operations or processes may be performed simultaneously. Some or all of the steps, operations, or processes may be performed automatically, without the intervention of a user. The accompanying method claims, if any, present elements of the various steps, operations or processes in a sample order, and are not meant to be limited to the specific order or hierarchy presented. 
     All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112 (f) unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.” Furthermore, to the extent that the term “include,” “have,” or the like is used, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim. 
     The Title, Background, Summary, Brief Description of the Drawings and Abstract of the disclosure are hereby incorporated into the disclosure and are provided as illustrative examples of the disclosure, not as restrictive descriptions. It is submitted with the understanding that they will not be used to limit the scope or meaning of the claims. In addition, in the Detailed Description, it can be seen that the description provides illustrative examples and the various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed subject matter requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed configuration or operation. The following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter. 
     The claims are not intended to be limited to the aspects described herein, but are to be accorded the full scope consistent with the language claims and to encompass all legal equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of 35 U.S.C. § 101, 102, or 103, nor should they be interpreted in such a way.