Patent Description:
The subject matter of the present application relates to controlling the flow of fluids through tubes.

Feeding sets can be used for enteral applications, and infusion sets can be used for parenteral applications. Enteral applications include using an enteral pump to administer nutrition (e.g., food, formula, medication, and the like) to a patient if the patient is unable to accept the nutrition without assistance. Parenteral applications include providing intravenous (IV) solutions to the patient to ensure adequate hydration and to provide needed nutrients, minerals, and/or medication. Often, the feeding or infusion set is placed in a free standing arrangement in which gravity causes the flow of formula or solution into the patient. The rate at which the formula or solution enters the patient can be generally controlled by various clamps, such as roller clamps.

In many applications, it is necessary to precisely control of the amount of solution or formula which enters the patient. A regulating device, such as an infusion pump, can be placed along the feeding or infusion set to control the rate at which the nutrition or solution is supplied to the patient. To avoid interference with the functioning of the regulating device, any clamps or valves that are present along the length of the tube may be opened to the fullest extent, with the expectation that the pump or other regulating device will control the flow through the tubing. However, emergencies and other distractions may prevent the medical personnel from properly setting up the feeding or infusion set with the automated regulating device. Furthermore, the feeding or infusion sets may be inadvertently dislodged from the regulating device during operation. In the unfortunate event that the regulating device is not properly connected to the feeding or infusion set due to negligent setup or unintentional dislodgement, an excessive flow of fluid may develop through the set under the force of gravity, which is a condition known as free-flow. During the free-flow condition, the patient may receive an excessive amount of nutrition, medication, and/or solution within a relatively short time period, which can be particularly dangerous if the medication is potent and/or the patient's body is not physically strong enough to adjust to the large inflow of nutrition (e.g., formula) or solution. <CIT> relates to an anti-free flow valve, enabling fluid flow as a function of pressure and selectively opened to enable free flow. <CIT> relates to a urinary control valve. <CIT> relates to a medical connector and method for manufacturing a medical connector.

In one or more embodiments, an anti-free-flow valve is provided that includes a tube and a membrane. The tube extends from a first end of the tube to a second end of the tube. The tube defines a hollow cavity. The membrane is attached to an interior surface of the tube and extends across the hollow cavity to obstruct fluid flow through the hollow cavity. The membrane is spaced apart from the first and second ends of the tube. The membrane defines a slit therethrough that is configured to transition from a closed state that restricts fluid flow to an open state that permits fluid flow through the slit responsive to compression or expansion of the tube proximate to the membrane.

In one or more embodiments, an anti-free-flow valve is provided that includes a tube, a membrane, and first and second engagement tabs. The tube defines a hollow cavity. The membrane is attached to an interior surface of the tube and extends across the hollow cavity to obstruct fluid flow through the hollow cavity. The membrane defines a slit through a thickness of the membrane. The first and second engagement tabs are attached to an exterior surface of the tube proximate to a location of the membrane. The first and second engagement tabs radially extend from the tube in opposite directions and are configured to be manipulated to compress or expand the tube to selectively transition the slit from a closed state that restricts fluid flow to an open state that permits fluid flow through the slit.

In one or more embodiments, an anti-free-flow valve is provided that includes a tube, a membrane, and first and second engagement tabs. The tube defines a hollow cavity. The membrane is attached to an interior surface of the tube and extends across the hollow cavity to obstruct fluid flow through the hollow cavity. The membrane defines a linear slit through a thickness of the membrane. The first and second engagement tabs are attached to an exterior surface of the tube proximate to a location of the membrane. The first and second engagement tabs radially extend from the tube in opposite directions along a tab axis that is parallel to the slit. The first and second engagement tabs are configured to be squeezed towards each other to compress the tube along the tab axis at the membrane which transitions the slit to an open state that permits fluid flow through the slit. Releasing the first and second engagement tabs causes the tube to decompress and the slit on the membrane to resiliently return to a closed state that restricts fluid flow.

The inventive subject matter will now be illustrated with reference to the following figures, in which:.

Embodiments set forth herein include a valve that is integrated with a tube. The valve has a membrane within the tube that obstructs flow of liquid or semi-liquid contents of the tube. The valve is configured to prevent free-flow of the contents, and for this reason is referred to herein as an anti-free-flow valve. The membrane of the valve can transition between a closed state and an open state. In the closed state, the membrane prevents the tube contents from passing beyond the membrane. In the open state, the membrane provides an opening that permits the contents to pass beyond the membrane via the opening. The membrane is biased towards to the closed state such that the membrane defaults to blocking the passage of the tube contents. The valve is designed to enable the membrane to transition to the open state based on mechanical manipulation of the tube itself. For example, compression and/or expansion of the tube may temporarily change the shape of the membrane which exposes or enlarges the opening to permit the contents to pass through the opening. The compressive forces can be applied by squeezing the tube, such as between two fingers or between prongs of a tool. The expansive forces can be applied by pulling two, circumferentially-opposite portions of the tube away from each other to radially stretch the tube. The pinching or pulling of the tube that actuates the valve can be performed manually by a human operator, semi-automatically by a human-controlled automated instrument or robot, or fully automatically. Upon releasing the tube or at least removing the compressive or expansive forces on the tube, the membrane resiliently returns to the closed state. The valve may also be configured to automatically open in response to the pressure exerted by the contents on the membrane exceeding a designated threshold force, and return to the closed state once the pressure drops below the designated threshold force.

The anti-free-flow valve can be used for various applications. In non-limiting examples, the valve can be integrated into the tubes of infusion (e.g., parenteral) sets and feeding (e.g., enteral) sets. When used in the infusion or IV set, the valve can be actuated to open the membrane in order to prime for pre-filling, then the valve is released. Once released, the valve returns to the closed state to prevent free-flow of the contents through the tube, preventing the patient from receiving an excessive amount or rate of the tube contents. When used in conjunction with a pump or other regulating device that controls the flow of the contents through the tube to the patient, the valve does not interfere with the operations of the pump to supply the contents at a designated rate or amount. For example, the pump may exert sufficient positive or negative pressure within the tube to cause the membrane to open without requiring active compression or expansion of the tube. The anti-free-flow valve described in the embodiments herein can also be utilized in other applications that require metering the flow of fluids and fluid-like contents through tubes, such as other types of medical applications, laboratory applications, industrial applications, and the like.

In at least one embodiment of the present disclosure, an anti-free-flow valve includes a tube and a membrane. The tube defines a hollow cavity. The membrane is attached to an interior surface of the tube and extends across the hollow cavity to obstruct fluid flow through the hollow cavity. The membrane is medially-located within the tube such that the membrane is spaced apart from ends of the tube. The membrane defines a narrow opening, referred to as a slit, therethrough. The slit may represent the only possible flow path across or beyond the membrane, such that when the slit is closed or sealed the membrane blocks fluid flow through the hollow cavity of the tube. The tube and the membrane are composed of one or more elastomeric materials which enable the tube and the membrane to deform and resiliently return to the pre-deformed shapes upon removal of the mechanical stimulus. Compression or expansion of the tube may cause the membrane flaps that define the slit to separate, establishing an opening through the membrane that permits fluid flow through the membrane.

One or more technical effects of the valve according to the embodiments described herein include increasing the safety and accuracy of metered flow operations, such as medical infusion sets and feeding sets, by preventing free-flow of the fluid contents through the tube. Anther technical effect is reduced complexity to manufacture and to operate relative to at least some known valves used for similar functions, as the known valves typically include multiple discrete rigid hardware pieces to which the tube connects. The anti-free-flow valve disclosed herein is integrated into the tube and may lack rigid hardware and tube coupling members. As described herein, the valve may have few components other than the membrane within the tube, which may simplify the manufacturing process. Furthermore, the valve may be manually actuated by simply compressing or expanding the tube, and thus does not require special tools or extended time to operate. Yet another technical effect that is related to the reduced complexity is reduced cost. The membrane could be integrally manufactured with the tube, even using the same elastomeric material composition. The relatively few components of the valve and the common materials can result in low manufacturing costs.

In the following description and claims, relative or spatial terms such as "front," "back," "side," "top," "bottom," "lateral," "longitudinal," and the like are only used to distinguish the referenced elements or features with respect to one another and make the language more readily understandable. The terms do not necessarily require particular positions, sizes, or orientations relative to the surrounding environment. Moreover, in the following description and claims, the terms "first," "second," and "third," etc. may be used as labels to distinguish similar elements (e.g., first and second side walls) and are not intended to impose numerical requirements on their objects.

<FIG> illustrates an anti-free-flow valve <NUM> according to an embodiment of the present disclosure. <FIG> illustrates a side view of the anti-free-flow valve <NUM> of <FIG>. The valve <NUM> includes a tube <NUM> and a membrane <NUM>.

The tube <NUM> extends from a first end <NUM> to a second end <NUM> that is opposite the first end <NUM>. The tube <NUM> has a short length between the first and second ends <NUM>, <NUM> in <FIG> and <FIG>, but the tube <NUM> can be longer than the illustrated segment length. For example, the tube <NUM> may have a length that is several meters. The tube <NUM> is hollow and defines a cavity <NUM> (e.g., a hollow cavity) that extends the length of the tube <NUM> from the first end <NUM> to the second end <NUM>. The tube <NUM> is flexible and compressible. For example, the tube <NUM> may be composed of one or more elastomeric materials, such as silicone rubber, polyethylene, polypropylene, and other thermoplastic elastomers. In a non-limiting embodiment, the material of the tube <NUM> may have a shore hardness that is in a range no less than <NUM> Shore A and no greater than <NUM> Shore A, such as no less than <NUM> Shore A and no greater than <NUM> Shore A. The specified durometer range may enable the tube <NUM> to have effective properties for the various applications of the valve <NUM>. The tube <NUM> may be molded into the hollow cylindrical shape. The inner diameter of the tube <NUM> (e.g., the diameter of the cavity <NUM>) may be selected based on application-specific considerations, such as the required flow rate of the contents that flow through the tube <NUM>, the viscosity of the contents, the size of any solid or semi-solid constituents within the contents, such as constituents within a feeding formula, the size of components that connect to the ends <NUM>, <NUM> of the tube <NUM> in an assembly, and the like. In a non-limiting embodiment, the inner diameter may be between <NUM> and <NUM>, such as between <NUM> and <NUM>, and more specifically about <NUM>.

Reference is additionally made to <FIG>, which shows a cross-sectional view of the anti-free-flow valve <NUM> taken along the line <NUM>-<NUM> in <FIG>. The membrane <NUM> is disposed within the cavity <NUM> and is spaced apart from the ends <NUM>, <NUM> of the tube. The membrane <NUM> is secured in a fixed position within the cavity <NUM>. The membrane <NUM> is attached to an interior surface <NUM> of the tube <NUM> that defines the cavity <NUM>. In at least one embodiment, the membrane <NUM> is continuously, uninterruptedly sealed to the tube <NUM> along the full circumference of the interior surface <NUM> such that there is no flow or leak paths between a perimeter edge <NUM> of the membrane <NUM> and the interior surface <NUM>. The membrane <NUM> has a thickness that extends from a first face <NUM> to a second face <NUM> that is opposite the first face <NUM>. In an embodiment in which the contents of the tube are controlled to flow or move in the direction indicated by arrow <NUM> in <FIG>, the first face <NUM> faces upstream and the second face <NUM> faces downstream. The thickness of the membrane <NUM> may be similar to the thickness of the tube <NUM>. The membrane thickness may be in the range between <NUM> and <NUM>, such as about <NUM>.

In an embodiment, the membrane <NUM> is concave such that a radial center point <NUM> of the membrane <NUM> is axially disposed between the perimeter edge <NUM> of the membrane <NUM> and the second end <NUM> of the tube <NUM>. Stated differently, the membrane <NUM> bows towards the second end <NUM>, and the center point <NUM> is the closest portion of the membrane <NUM> to the second end <NUM>. In an embodiment, the concave curvature is three-dimensional, such that the membrane <NUM> is semi-spherical.

The membrane <NUM> may be integrally connected to the tube <NUM>. For example, the perimeter edge <NUM> of the membrane <NUM> may be seamlessly attached to the interior surface <NUM> of the tube <NUM>. The tube <NUM> and the membrane <NUM> may define a unitary, one-piece, monolithic structure. For example, the membrane <NUM> may be formed with the tube <NUM> during a common manufacturing process. The membrane <NUM> therefore may be composed of the same elastomeric material as the tube <NUM>. In an alternative embodiment, the membrane <NUM> may be separately formed from the tube <NUM> and subsequently secured to the interior surface <NUM> via an adhesive, a heat application, or the like.

The membrane <NUM> defines a slit <NUM> that extends through the full thickness of the membrane <NUM> between the first and second faces <NUM>, <NUM>. The slit <NUM> is a narrow slice or cut which may be formed by penetrating the membrane <NUM> with a fine cutting instrument, such as a blade. In the illustrated embodiment, the slit <NUM> is linear. The slit <NUM> may extend through the center point <NUM> of the membrane <NUM>. The linear slit <NUM> may extend the full arc length from the perimeter edge <NUM> of the membrane <NUM> through the center point <NUM> to the opposite location of the perimeter edge <NUM>. In such an embodiment, the slit <NUM> bifurcates the membrane <NUM> into two halves or flaps. Alternatively, the slit <NUM> may have a shorter length such that the two segments of the membrane <NUM> on either side of the slit <NUM> are integrally connected at the ends of the slit <NUM>.

When the membrane <NUM> is free of interior fluid pressures within the cavity <NUM> and free of mechanical forces exerted on the exterior of the tube <NUM>, the edges of the membrane <NUM> that define the slit <NUM> press up against each other. The edges of the membrane <NUM> pressing against each other close or seal the slit <NUM> to restrict (e.g., block) fluid flow through the slit <NUM>. This state of the membrane <NUM> is referred to as a closed state. The membrane <NUM> is biased towards the closed state, so the membrane <NUM> is referred to as self-sealing.

As shown in <FIG>, when fluid contents within the tube <NUM> flow in the direction <NUM>, due to gravity for example, the contents abut against the concave membrane <NUM> in the closed state. The membrane <NUM> blocks flow of the contents beyond the membrane <NUM> unless or until sufficient force is applied to cause the membrane <NUM> to transition to an open state which permits the contents to pass through the slit <NUM> beyond the membrane <NUM>. The curved shape of the membrane <NUM> channels or funnels the contents to the slit <NUM> at the center point <NUM>. In one example, if a pump connected to the tube <NUM> exerts sufficient positive or negative pressure based on the position of the pump, the pressure may cause the membrane <NUM> to deform from the closed state to the open state. For example, the edges that define the slit <NUM> may pull apart from each other which enlarges and deforms the slit <NUM> to provide a void through the membrane <NUM>. The contents therefore can be pushed or sucked through the slit <NUM> if the internal pressure is sufficient to overcome the natural resiliency of the membrane <NUM> to seal the slip <NUM>.

The membrane <NUM> can also transition to the open state by compression or expansion of the tube <NUM> proximate to the membrane <NUM>, as described herein. The compression or expansion proximate to the membrane <NUM> refers to forces exerted on the tube <NUM> that are close enough to the membrane <NUM> such that the deformation of the tube <NUM> causes the membrane <NUM> within the tube <NUM> to deform. The forces may be exerted on the tube <NUM> at the location of the membrane <NUM> or within a designated proximity of the membrane <NUM>, which may depend on various parameters such as the internal diameter of the tube <NUM> and the material properties of the tube <NUM>.

Referring to <FIG> and <FIG>, the valve <NUM> in at least one embodiment includes a first engagement tab <NUM> and a second engagement tab <NUM> that can be used to compress and/or expand the tube <NUM>. The engagement tabs <NUM>, <NUM> are coupled to an exterior surface <NUM> of the tube <NUM> and radially extend from the tube <NUM> in opposite directions from each other. For example, the engagement tabs <NUM>, <NUM> may be coupled to the tube <NUM> at locations that are <NUM> degrees apart in the circumferential dimension but at the same position along the length of the tube <NUM>. The engagement tabs <NUM>, <NUM> are located at or proximate to the location of the membrane <NUM>. The engagement tabs <NUM>, <NUM> are fixed to the tube <NUM> and configured to be manipulated to selectively compress or expand the tube <NUM> to transition the membrane <NUM> to the open state. The tabs <NUM>, <NUM> may be sized and shaped to accommodate manual manipulation, such as by two fingers pressing the engagement tabs <NUM>, <NUM> together or two sets of fingers gripping the engagement tabs <NUM>, <NUM> to pull the tabs <NUM>, <NUM> in opposite directions. The tabs <NUM>, <NUM> may also accommodate manipulation by instruments, such as tools or robots that engage the tabs <NUM>, <NUM>. In an embodiment, the engagement tabs <NUM>, <NUM> may be integrally formed with the tube <NUM>, such as formed during a common molding process with the tube <NUM>. Alternatively, the engagement tabs <NUM>, <NUM> may be discretely formed separate from the tube <NUM> and subsequently secured to the exterior surface <NUM> via adhesive, a heat treatment, a pressure treatment, or the like.

The engagement tabs <NUM>, <NUM> in various embodiments can have different shapes and/or sizes. In the illustrated embodiment, the engagement tabs <NUM>, <NUM> each have a trunk <NUM> and a cap <NUM>. The trunk <NUM> is a base or post that attaches to the tube <NUM> and extends radially outward from the exterior surface <NUM>. The cap <NUM> is mounted to the end of the trunk <NUM> such that the trunk <NUM> is between the tube <NUM> and the cap <NUM>. The cap <NUM> has a broader size than the trunk <NUM> in the illustrated embodiment. For example, portions of the cap <NUM> extend beyond and overhang the trunk <NUM>. The overhanging portions can be gripper or grasped by a user's fingers or an instrument to enable pulling the engagement tabs <NUM>, <NUM> apart to expand the tube <NUM>. The cap <NUM> has an outer surface <NUM> that faces away from the tube <NUM>. The outer surface <NUM> is sufficiently broad to enable a user's finger or an instrument to press on the outer surface <NUM> to enable pushing the engagement tabs <NUM>, <NUM> together to compress the tube <NUM>. As shown in <FIG>, the outer surface <NUM> is concave. The concave outer surface <NUM> can provide tactile guidance for the user when placing the user's fingers on the engagement tabs <NUM>, <NUM>.

<FIG> is an end view of the anti-free-flow valve <NUM> according to the embodiment shown in <FIG> with the membrane <NUM> in the closed state. <FIG> is an end view of the anti-free-flow valve <NUM> of <FIG> with the membrane <NUM> in the open state. As shown in <FIG>, the slit <NUM> is linear and centrally located on the membrane <NUM>. The engagement tabs <NUM>, <NUM> project from the tube <NUM> in opposite directions along a tab axis <NUM>. The tab axis <NUM> is parallel to the slit <NUM>. <FIG> shows the valve <NUM> in a default resting state. In the illustrated embodiment, the membrane <NUM> can be selectively transitioned to the open state by compressing the tube <NUM>. As shown in <FIG>, forces applied on the engagement tabs <NUM>, <NUM> in the direction of arrows <NUM>, <NUM>, respectively, squeeze the engagement tabs <NUM>, <NUM> towards each other. The engagement tabs <NUM>, <NUM> compress the tube <NUM> along the tab axis <NUM>. The compression of the tube <NUM> deforms the membrane <NUM>, which causes the slit <NUM> to open and enlarge. The narrow slit <NUM> opens to define a passage <NUM> through the membrane <NUM>. When in the open state, the fluid or semi-fluid contents of the tube <NUM> can pass beyond the membrane <NUM> through the passage <NUM>. Upon removal or at least reduction of the forces in the directions <NUM>, <NUM>, the tube <NUM> and the membrane <NUM> resiliently return towards the inherent molded shapes thereof. The flaps of the membrane <NUM> move together and close or seal the slit <NUM> as the membrane decompresses. Thus, a user can selectively open or bypass the anti-free-flow valve <NUM> by squeezing the engagement tabs <NUM>, <NUM> together, and can release the tabs <NUM>, <NUM> to close the valve <NUM>.

<FIG> is an end view of the anti-free-flow valve <NUM> according to a second embodiment showing the membrane <NUM> in the closed state. <FIG> is an end view of the anti-free-flow valve <NUM> of <FIG> showing the membrane <NUM> in the open state. The only difference between the illustrated embodiment and the first embodiment shown in <FIG> is the orientation of the linear slit <NUM> relative to the positioning of the engagement tabs <NUM>, <NUM>. For example, the tab axis <NUM> defined by the engagement tabs <NUM>, <NUM> is orthogonal to the orientation of the slit <NUM> in <FIG>, instead of parallel as shown in <FIG>. In the illustrated arrangement, the membrane <NUM> transitions from the closed state to the open state by expanding the tube <NUM> along the tab axis <NUM>. The expansion can be achieved by pulling the engagement tabs <NUM>, <NUM> apart from each other in the direction of arrows <NUM>, <NUM>. For example, the user may grip the engagement tabs <NUM>, <NUM> at the overhanging portions of the caps <NUM>. The expansion of the tube <NUM> deforms the membrane <NUM>, which causes the slit <NUM> to open and enlarge to define the passage <NUM> through the membrane <NUM>. The first embodiment shown in <FIG> may represent a compression-actuated anti-free-flow valve <NUM>, and the second embodiment shown in <FIG> may be an expansion-actuated anti-free-flow valve <NUM>.

<FIG> is an end view of the anti-free-flow valve <NUM> according to a third embodiment showing the membrane <NUM> in the closed state. The third embodiment may represent a hybrid of the first and second embodiments described above. For example, the membrane <NUM> in <FIG> has the (first) slit <NUM> and a second slit <NUM> therethrough. The two slits <NUM>, <NUM> intersect. In an embodiment, each slit <NUM>, <NUM> is linear and the slits <NUM>, <NUM> are oriented orthogonal to each other to form an X-shaped incision in the membrane <NUM>. The first slit <NUM> is parallel to the tab axis <NUM>, and the second slit <NUM> is orthogonal to the tab axis <NUM>. The anti-free-flow valve <NUM> is designed to selectively open based on either of tube compression via pressing the engagement tabs <NUM>, <NUM> together or tube expansion via pulling the engagement tabs <NUM>, <NUM> apart.

<FIG> is an end view of the anti-free-flow valve <NUM> of <FIG> showing the membrane <NUM> in a first open state. <FIG> is an end view of the anti-free-flow valve <NUM> of <FIG> showing the membrane <NUM> in a second open state. In the first open state shown in <FIG>, the engagement tabs <NUM>, <NUM> are pressed together similar to the actuation shown in <FIG>. The result is that the first slit <NUM> opens and enlarges to define the passage <NUM> that permits fluid flow through the membrane <NUM>. The second slit <NUM> may open only slightly in the region proximate to the intersection with the first slit <NUM> because the compression of the tube <NUM> limits the spreading of the second slit <NUM>. The second open state shown in <FIG> is essentially the inverse as the first open state. When the engagement tabs <NUM>, <NUM> are pulled apart, similar to the actuation shown in <FIG>, the second slit <NUM> opens and enlarges to define the passage <NUM> that permits fluid flow through the membrane <NUM>. The first slit <NUM> may open only slightly in the region proximate to the intersection because the expansion of the tube <NUM> limits the spreading of the first slit <NUM>. Thus, the hybrid anti-free-flow valve <NUM> shown in <FIG> can be actuated from the closed state to the open state by either pulling or pressing the engagement tabs <NUM>, <NUM>, which provides flexibility for use in various different applications.

In an embodiment, an anti-free-flow valve is provided that includes a tube and a membrane. The tube extends from a first end of the tube to a second end of the tube. The tube defines a hollow cavity. The membrane is attached to an interior surface of the tube and extends across the hollow cavity to obstruct fluid flow through the hollow cavity. The membrane is spaced apart from the first and second ends of the tube. The membrane defines a slit therethrough that is configured to transition from a closed state that restricts fluid flow to an open state that permits fluid flow through the slit responsive to compression or expansion of the tube proximate to the membrane.

Optionally, the membrane is concave such that a center point of the membrane is axially disposed between a perimeter edge of the membrane and the second end of the tube. The membrane may be semi-spherical, and the slit extends through the center point of the membrane.

Optionally, the membrane is integrally connected to the tube to define a seamless monolithic structure. Optionally, the membrane is attached to the interior surface along an entire circumference of the tube such that the slit represents an only flow passageway with the hollow cavity across the membrane. Optionally, the slit is linear and the membrane is biased towards the closed state of the slit. Optionally, the tube and the membrane comprise an elastomeric material that has a shore hardness in a range no less than <NUM> Shore A and no greater than <NUM> Shore A. Optionally, the slit is a first slit, and the membrane also defines a second slit that intersects the first slit.

The anti-free-flow valve may also include a first engagement tab and a second engagement tab attached to an exterior surface of the tube proximate to a location of the membrane and radially extending from the tube in opposite directions. The first and second engagement tabs are configured to be manipulated to compress or expand the tube to selectively transition the slit to the open state. Each of the first and second engagement tabs may include a cap and a trunk disposed between the cap and the tube. The cap has a broader size than the trunk. An outer surface of the cap of each of the first and second engagement tabs radially faces away from the tube and defines a concave curve.

In an embodiment, an anti-free-flow valve is provided that includes a tube, a membrane, and first and second engagement tabs. The tube defines a hollow cavity. The membrane is attached to an interior surface of the tube and extends across the hollow cavity to obstruct fluid flow through the hollow cavity. The membrane defines a slit through a thickness of the membrane. The first and second engagement tabs are attached to an exterior surface of the tube proximate to a location of the membrane. The first and second engagement tabs radially extend from the tube in opposite directions and are configured to be manipulated to compress or expand the tube to selectively transition the slit from a closed state that restricts fluid flow to an open state that permits fluid flow through the slit.

Optionally, the slit is linear, and the first and second engagement tabs radially extend from the tube in opposite directions along a tab axis that is parallel to the slit. Compression of the tube by squeezing the first and second engagement tabs towards each other transitions the slit to the open state.

Optionally, the slit is linear, and the first and second engagement tabs radially extend from the tube in opposite directions along a tab axis that is orthogonal to the slit. Expansion of the tube by pulling the first and second engagement tabs away from each other transitions the slit to the open state. Optionally, the slit is a first slit, and the membrane also defines a second slit that is linear and oriented orthogonal to the first slit. Compression of the tube by squeezing the first and second engagement tabs towards each other transitions the second slit to the open state.

Optionally, the tube extends from a first end of the tube to a second end of the tube. The membrane is spaced apart from the first and second ends. Optionally, the membrane is integrally connected to the tube to define a seamless monolithic structure. Optionally, the membrane is concave such that a center point of the membrane is axially disposed between a perimeter edge of the membrane that is attached to the interior surface and an end of the tube.

Optionally, each of the first and second engagement tabs includes a cap and a trunk disposed between the cap and the tube. The cap has a broader size than the trunk.

In an embodiment, an anti-free-flow valve is provided that includes a tube, a membrane, and first and second engagement tabs. The tube defines a hollow cavity. The membrane is attached to an interior surface of the tube and extends across the hollow cavity to obstruct fluid flow through the hollow cavity. The membrane defines a linear slit through a thickness of the membrane. The first and second engagement tabs are attached to an exterior surface of the tube proximate to a location of the membrane. The first and second engagement tabs radially extend from the tube in opposite directions along a tab axis that is parallel to the slit. The first and second engagement tabs are configured to be squeezed towards each other to compress the tube along the tab axis at the membrane which transitions the slit to an open state that permits fluid flow through the slit. Releasing the first and second engagement tabs causes the tube to decompress and the slit on the membrane to resiliently return to a closed state that restricts fluid flow.

It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the inventive subject matter without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the inventive subject matter, they are by no means limiting and are example embodiments. Many other embodiments will be apparent to one of ordinary skill in the art upon reviewing the above description. The scope of the inventive subject matter should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein.

This written description uses examples to disclose several embodiments of the inventive subject matter and also to enable one of ordinary skill in the art to practice the embodiments of inventive subject matter, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the inventive subject matter is defined by the claims, and may include other examples that occur to one of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claim 1:
An anti-free-flow valve (<NUM>) comprising:
a tube (<NUM>) extending from a first end of the tube to a second end of the tube, the tube (<NUM>) defining a hollow cavity, and
a membrane (<NUM>) attached to an interior surface of the tube and extending across the hollow cavity to obstruct fluid flow through the hollow cavity, the membrane spaced apart from the first and second ends (<NUM>, <NUM>) of the tube, wherein the membrane (<NUM>) defines a slit (<NUM>) therethrough that is configured to transition from a closed state that restricts fluid flow to an open state that permits fluid flow through the slit (<NUM>) responsive to compression or expansion of the tube proximate to the membrane (<NUM>),
characterised in that the membrane (<NUM>) has a concave curved shape that extends to a center point of the membrane and the slit (<NUM>) extends through the center point, the membrane oriented relative to a direction (<NUM>) of the fluid flow through the tube such that the concave curved shape funnels the fluid flow towards the slit (<NUM>).