Patent Description:
Infusion IV sets are generally used in infusion therapy in order to deliver medication from a pre-filled container, e.g., an IV bottle or bag containing the desired medication, to a patient. Generally, the IV tubing is connected to a catheter and inserted into the localized area to be treated. In some cases, there is a need to deliver multiple medications to the patient in potentially differing dosages, thereby causing the need for an IV extension set having multiple branches of tubing or fluid lines through which the multiple medications may be dispensed to the patient.

Medical infusion therapy involves the administration of medication through a needle or catheter. The medication may be administered using intravenous, intramuscular, or epidural techniques. Typically, infusion therapy includes a fluid source coupled through tubing to a patient's intravenous needle or a catheter. The fluid, which may comprise medication or any other fluid, is usually dripped from the fluid source, through a fluid pathway, and into the patient. Typically, a primary fluid source and one or more secondary fluid sources may be joined to the fluid pathway between the source and the patient.

The primary and secondary fluid sources may be joined in the fluid pathway such that the secondary fluid may be delivered concurrently with the primary fluid. Alternatively, flow of the primary fluid may be halted where the pressure head at the secondary fluid source is greater than that at the primary fluid source, thereby allowing delivery of the secondary fluid. Delivery of the primary fluid may then be restarted after flow of the secondary fluid has ceased.

During infusion with IV sets, a secondary drug feed could potentially flow backwards into primary IV line leading to under infusion of the secondary drug. Though a check valve may be positioned in the primary line to prevent backflow, check valves are prone to failure. Some common reasons for check valve failure are due to debris existing in infusates and minimal pressure differential at the back check valve affecting its performance.

<CIT> discloses a drip chamber having a floating pressure-sensitive ball, which responds to priming pressure and the pressure of liquid in the administration set, and a resilient seat shaped so as to provide line contact with the ball. An inwardly- turned lip on the seat inwardly flexes as the ball pushes into the valve seat to maintain the line contact.

<CIT> discloses a drip chamber for use with an infusion appts. It has a sight housing with an inlet and outlet and a cleaning strainer. The chamber contains a float acting against a lower seat connected to the outlet so as to regulate the min. height of the infusion solution in it. When a pressure occurs at the outlet exceeding that of the solution in the chamber, the float shuts off a top seat connected to the inlet.

<CIT> discloses a universal drip chamber and spike assembly for use with a source of intravenous liquid contained in a bottle having a neck with a permeable stopper disposed in the neck and for use with a tube adapted to be connected to a patient. The Universal drip chamber comprises a body defining the upper portion of a drip chamber. The drip chamber body has a relatively rigid substantially transparent wall surrounding the upper portion of the chamber and being open at its lower end. A drip chamber booth formed of a flexible rubber-like material is secured to the lower end of the said drip chamber body and defines the lower portion of the drip chamber. The booth has an outlet flow passage extending through the lower extremity of the same and is in communication with the drip chamber. The booth has means forming a valve seat in the lower portion of the drip chamber surrounding the outlet flow passage. A ball capable of floating in said liquid is disposed in said drip chamber and is capable of engaging said valve seat to prevent the flow of liquid from said drip chamber through the outlet flow passage in said booth. The booth is sufficiently compliant so that it can be squeezed by hand to dislodge the ball from the valve seat. The booth has sufficient length above the seat so that when the ball is disposed in the seat, the booth can be squeezed by hand without lodging the ball to pump liquid into the drip chamber. The spike assembly has a first flow passage therein in communication with the drip chamber whereby when the spike is completely inserted into the stopper in the bottle, fluid can pass from the bottle into the drip chamber. The spike assembly is provided with first and second steps with the second step being closer to outer end of the spike assembly than the first step. The first flow passage opens through the first step. The spike assembly is provided with a second flow of passage which is formed in the spike assembly and has one end opening through the second step and has the other end open to the atmosphere. Hydrophobic air filter means is disposed in the second flow passage so that air passing from the atmosphere and through said second passage must pass through the hydrophobic filter.

The invention is defined by the subject-matter of claim <NUM>.

In accordance with various embodiments of the present disclosure, a drip chamber device may include a housing including an inlet and an outlet disposed downstream of the inlet, and a chamber defined by an inner circumferential surface of the housing. The chamber may fluidly connect the inlet with the outlet. A valve member may be disposed in the chamber to move between (i) a closed state where fluid communication between the inlet and the chamber is blocked, and (ii) an open state where fluid communication between the inlet and the chamber is not blocked, based on a level of fluid within the chamber.

In accordance with various embodiments of the present disclosure, a drip chamber device may include a housing having a top end including an inlet for receiving a primary fluid, an opposing bottom end including an outlet for dispensing fluid from the housing, an intermediate section between the top and bottom ends, and a sidewall having (i) a first portion extending radially outward from the top end to the intermediate section of the housing, and (ii) a second portion extending radially inward from the intermediate section to the bottom end of the housing. An inner circumferential surface of the sidewall may define a chamber. The drip chamber device may further include a sealing ring circumferentially disposed along the inner circumferential surface, and a valve member moveably disposed in the chamber. The valve member may be displaceable in a proximal direction into the sealing ring by a buoyant force when fluid level in the chamber exceeds a predetermined level.

The following figures are included to illustrate certain aspects of the embodiments, and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, as will occur to those skilled in the art and having the benefit of this disclosure.

The present description relates in general to flow control devices, and more particularly to flow control devices having a valve member capable of preventing under infusion in IV sets with a secondary fluid line, as well as preventing backflow of drug from the secondary fluid line into the primary fluid line.

IV sets with a secondary fluid line tend to experience under infusion of the secondary drug due to backflow of the secondary drug into the primary line resulting from failure of the check valve in the primary fluid line. The most frequent causes of failure of the check valve are due to debris accumulated at the time of spiking and seeping of drug in the secondary fluid line into the primary fluid line at low pressures. A common cause of under-infusion is dilution of drug at the time of back priming of the secondary IV and also at the time of equal head in the primary and secondary fluid lines. Other causes include dead volume in the secondary fluid line, as well as time taken to infuse the drug. The drip chamber devices of the various embodiments described herein overcome the above issues commonly associated with IV sets having primary and secondary fluid lines. In particular, various embodiments of the present disclosure are directed to providing a drip chamber device that prevents backflow of secondary drug into the primary fluid line. When head heights at the primary fluid source and the secondary fluid source are equal, both primary and secondary fluids may be delivered in equal proportion.

<FIG> illustrates a multiple line IV extension set <NUM> that includes a drip chamber device <NUM> in accordance with some embodiments of the present disclosure. As depicted, IV set <NUM> includes a primary fluid system <NUM> and a secondary fluid system <NUM>. An IV pump (optional) may receive fluid from primary fluid system <NUM> and secondary fluid system <NUM> via a primary IV fluid line <NUM> and a secondary IV fluid line <NUM>, and may control and dispense the fluids therefrom to a patient.

In some embodiments, primary fluid system <NUM> may include a primary fluid source or container such as a primary intravenous (IV) fluid bag <NUM>, which may include or contain a first medical fluid, e.g., saline solution or other medicinal fluid or drug to be administered to the patient. In accordance with some embodiments, a secondary fluid system <NUM> may include a secondary fluid source or container such as a secondary IV fluid bag <NUM>, which may contain a second medical fluid, e.g., drugs or other secondary fluid to be supplied to the patient for treatment. In some embodiments, the second medical fluid may be different from the first medical fluid. However, the various embodiments of the present disclosure are not limited to the aforementioned configuration. In other embodiments, the first and second fluids may be the same.

According to various embodiments of the present disclosure, as illustrated in <FIG>, primary IV fluid bag <NUM>, which holds a primary fluid is positioned at a lower axial position or height than the secondary IV fluid bag <NUM>. For example, the primary IV fluid bag <NUM> may be hung on a suspension system or hanger and then the secondary IV fluid bag <NUM> may be hung above the primary IV fluid bag and may be coupled to the secondary fluid line <NUM>, which may be connected to the primary fluid line <NUM> via a connector (e.g., a y-site connector).

<FIG> illustrates a perspective view of a drip chamber device <NUM>, in accordance with some embodiments of the present disclosure. <FIG> illustrates a front view of the drip chamber device <NUM> of <FIG>, in accordance with some embodiments of the present disclosure. As illustrated, the drip chamber device <NUM> may have a top end <NUM> including an inlet <NUM> for receiving a primary fluid, an opposing bottom end <NUM> including an outlet <NUM> for dispensing fluid from the housing <NUM>, and an intermediate section <NUM> positioned between the top and bottom ends <NUM> and <NUM> of the housing <NUM>. The housing <NUM> may further include a sidewall extending from the top end <NUM> to the bottom end <NUM> of the housing <NUM>. For example, in some embodiments, the sidewall may include a first sidewall or sidewall portion <NUM> and a second sidewall or sidewall portion <NUM>. The first sidewall or sidewall portion <NUM> and the second sidewall or sidewall portion <NUM> may define an inner circumferential surface <NUM> of the housing.

As depicted in <FIG>, the first sidewall or sidewall portion <NUM> may extend radially outward and distally from the top end <NUM> of the housing <NUM>. Similarly, the second sidewall or sidewall portion <NUM> may extend radially inward and distally from the first sidewall or sidewall portion <NUM> to the bottom end <NUM> of the housing <NUM>. In particular, the first sidewall or sidewall portion <NUM> may extend radially outward from the top end <NUM> of the housing <NUM> to the intermediate section <NUM> of the housing <NUM>. The second sidewall or sidewall portion <NUM> may extend radially inward from the intermediate section <NUM> to the bottom end <NUM> of the housing <NUM>. In a similar manner, the second sidewall or sidewall portion <NUM> may extend radially outward and proximally from the bottom end <NUM> of the housing <NUM> to the intermediate section <NUM> of the housing. The first sidewall or sidewall portion <NUM> may extend radially inward and proximally from the intermediate section <NUM> of the housing <NUM> to the top end of the housing <NUM>.

Accordingly, each of the first sidewall or sidewall portion <NUM> and the second sidewall or sidewall portion <NUM> may have a conical shape. The housing <NUM> may thus in some embodiments have a diamond shape. However, the various embodiments of the present disclosure are not limited to the aforementioned configuration. In other embodiments, the housing may have an oblong or oval shape, or any other shape where the top and bottom ends <NUM> and <NUM> are symmetrically disposed with respect to each other and the intermediate section <NUM> is disposed radially outward with respect to the first and second ends <NUM> and <NUM>.

Accordingly, the drip chamber device <NUM> may be referred to as a convergent-divergent drip chamber device based on the shape of the housing where the first sidewall or sidewall portion <NUM> extends radially outward (i.e., diverges) from the top end <NUM>, and the second sidewall or sidewall portion <NUM> extends radially inward (i.e., converges) from the first sidewall or sidewall portion <NUM>. The convergent-divergent conical shape of the drip chamber device may provide several advantages, as shall be discussed in further detail below.

In accordance with various embodiments of the present disclosure, the inner circumferential surface <NUM> of the housing <NUM> may define a chamber <NUM>, which fluidly connects the inlet <NUM> with the outlet <NUM>. As depicted in <FIG>, with continued reference to <FIG>, the drip chamber device <NUM> may further include a valve member <NUM> movably disposed in the chamber <NUM>. As shall be described in further detail below, based on a level of fluid within the chamber <NUM>, valve member <NUM> may be configured to move between (i) a closed state where fluid communication between the inlet <NUM> and the chamber <NUM> is blocked, and (ii) an open state where fluid communication between the inlet <NUM> and the chamber <NUM> is not blocked.

In some embodiments, the valve member <NUM> may be a spherical ball or disc. In other embodiments, valve member <NUM> may be an oblong or oval ball or disc. The valve member <NUM> may be a solid body or hollow ball having a density less than the density of the primary fluid, the secondary fluid, or a combination of the primary and secondary fluids in the chamber <NUM>. Accordingly, the valve member having the lesser density will float on the fluid <NUM> in the chamber which has a higher density. Since the fluid <NUM> in the chambers has the higher density, the fluid <NUM> may exert a buoyant force on the valve member <NUM>, causing it to move upwards (proximally) as the level of the fluid in the chamber continues to rise. In some embodiments, the valve member <NUM> may be formed of a material including at least one of Isoprene rubber, polyethylene (PE) foam, ethylene propylene diene monomer (EPDM) foam, or any other material having a density less than the density of the primary fluid, the secondary fluid, or a combination of the primary and secondary fluids in the chamber.

According to various embodiments of the disclosure, the drip chamber device <NUM> may further include a sealing ring <NUM> having a hollow interior <NUM> for accommodating and engaging the valve member <NUM> in order to block fluid in the chamber <NUM> from flowing into the IV bag <NUM>, which would otherwise cause underinfusion of the secondary fluid to the patient. As depicted, the sealing ring <NUM> may be circumferentially disposed on the inner circumferential surface <NUM> of the housing <NUM>. In some embodiments, the sealing ring <NUM> may be disposed adjacent to and distally from the top end <NUM> of the housing <NUM>. For example, the sealing ring may be positioned on the inner circumferential surface <NUM> at a distance from the top end <NUM> that is greater than or equal to the radius of the valve member, e.g., spherical ball <NUM>. As depicted, the inner diameter D2 of the sealing ring <NUM> may be substantially equal to the diameter D1 of the valve member <NUM>. For example, the inner diameter D2 of the sealing ring <NUM> may be equal to or less than the diameter D1 of the valve member <NUM> to allow valve member <NUM> to be accommodated and press-fit or interference-fit therein. Although the sealing ring <NUM> is illustrated as having a flat or planar profile, the various embodiments of the present disclosure are not limited to the aforementioned configuration. For example, in some embodiments the sealing ring <NUM> may have a shape that tapers upwards (proximally) so as to direct or otherwise guide the valve <NUM> towards the inner diameter D2 of sealing ring <NUM> and the central axis X (illustrated in <FIG>).

Accordingly, the valve member <NUM> may be securely accommodated in the sealing ring <NUM> with the maximum of the diameter D1 of the valve member <NUM> forming an interference fit or a press fit with the inner diameter D2 of the sealing ring <NUM>. As shall be described in further detail below, the valve member <NUM> being securely accommodated or fit in the sealing ring <NUM> produces a closed state in which fluid communication between the inlet <NUM> and the chamber <NUM> is blocked. Accordingly, fluid in the chamber <NUM> may be prevented from otherwise flowing into the primary IV bag <NUM> via the inlet <NUM>. Advantageously, secondary fluid having entered the chamber <NUM> may be prevented from entering primary IV fluid bag <NUM> and causing a situation where insufficient secondary fluid is delivered to the patient (under infusion). Further, the aforementioned configuration of the drip chamber device including valve member <NUM> and sealing ring <NUM> may also be advantageous in preventing delay of administration of the secondary fluid (which would have otherwise entered the primary IV bag <NUM>) to the patient. As shall also be described in further detail below, in the open state the valve member <NUM> may be disposed outside of the sealing ring <NUM>, thereby allowing fluid communication between the inlet <NUM> and the outlet <NUM>.

<FIG> illustrates a perspective view of a base plate <NUM> of the drip chamber device <NUM> of <FIG>, in accordance with some embodiments of the present disclosure. <FIG> illustrates a cross-sectional view of the base plate <NUM> of <FIG> along line 2D-2D, in accordance with some embodiments of the present disclosure. As depicted in <FIG> with continued reference to <FIG>, the bottom end <NUM> of the housing <NUM> may include the base plate <NUM> on which the valve member <NUM> may be seated in the open state. The base plate <NUM> may have a top surface <NUM>, a bottom surface <NUM>, and a plurality of valve support members <NUM> protruding proximally and longitudinally from the top surface <NUM> of the base plate.

As further depicted, the base plate <NUM> may include an aperture <NUM> extending from the top surface <NUM> through the bottom surface <NUM> of the base plate <NUM>. The aperture <NUM> may fluidly communicate the chamber <NUM> with the outlet <NUM>. The valve support members <NUM> may be radially spaced apart about a central longitudinal axis X of the drip chamber device. In particular, valve support members <NUM> may be radially spaced apart about the aperture <NUM>. Each spacing between adjacent valve support members may define a flow guide portion <NUM> through which fluid exiting the chamber <NUM> flows into the outlet <NUM> via aperture <NUM>. The aforementioned configuration of the valve support members <NUM> protruding from the top surface is advantageous in that in the open state where fluid flows from the chamber <NUM> into the outlet <NUM>, the valve member <NUM> may be seated and supported on the valve support members at a height H1 above the aperture <NUM>. Accordingly, fluid flow into the outlet via the chamber <NUM> may not be occluded or otherwise interfered with by the valve member <NUM> seated above the aperture <NUM>.

According to various embodiments of the present disclosure, the top surface <NUM> of the base plate <NUM> may be a ramped surface, which is angled and tapers radially inward from an outer periphery <NUM> of the base plate <NUM> to the aperture <NUM> of the base plate <NUM>. In particular, as illustrated in <FIG>, the base plate <NUM> may taper from a height H3 at the outer periphery <NUM> to a height H4 at the aperture <NUM>. The aforementioned configuration of the ramped or tapered structure of the base plate <NUM> may be advantageous in providing a downwardly (distally) inclined surface along which fluid in the chamber may flow along and be guided into the aperture <NUM>.

<FIG> illustrate operational states of a drip chamber device <NUM>, in accordance with some embodiments of the present disclosure. <FIG> illustrates an operational state of the drip chamber device <NUM> when a primary fluid flows into the drip chamber device <NUM>. As depicted, the valve member <NUM> is seated on the valve support members <NUM> at the raised position relative to the aperture <NUM> (illustrated in <FIG>). In this position, the open state, fluid may flow from the primary IV bag <NUM> into the chamber <NUM> via the inlet <NUM> as illustrated by the arrows. Once the primary fluid enters the chamber, the primary fluid may flow onto the top surface <NUM> of base plate <NUM>. Due to the ramped, angled, or inclined structure of the base plate <NUM>, the fluid may be guided or urged to flow down the inclined surface of the base plate <NUM> and into the outlet <NUM> via the aperture <NUM>. The spacings between adjacent valve support members that define flow guide portions <NUM> may further assist in guiding the primary fluid towards the aperture <NUM>.

<FIG> illustrates an operational state of the drip chamber device <NUM> where secondary fluid backflows into the primary fluid line <NUM> and the drip chamber device <NUM> from the secondary fluid line <NUM>. As depicted, as the secondary fluid enters and collects in the drip chamber device <NUM>, the secondary fluid may exert a buoyant force F on the valve member <NUM>. When the buoyant force F exceeds a downward force applied to the fluid by the weight of the valve member <NUM>, the valve member <NUM> may be translated or otherwise moved proximally (upstream or upwards) towards the top end <NUM> of the housing <NUM>.

<FIG> illustrates an operational state of the drip chamber device of <FIG> where secondary fluid backflow into the drip chamber device continues until fluid in the drip chamber reaches a predetermined level and the buoyant force on the valve member engages the valve member in the sealing ring to block fluid flow from the chamber to the inlet in accordance with some embodiments of the present disclosure. As depicted, as the secondary fluid continues to backflow into the primary fluid line <NUM>, the level of the fluid in the chamber <NUM> continues to rise until it reaches a predetermined level where the buoyant force pushes the valve member <NUM> into the sealing ring <NUM>. Since the diameter D1 of the valve member <NUM> is greater than or equal to the inner diameter of the sealing member <NUM>, the valve member forms an interference fit or a press fit in the sealing ring <NUM>. Accordingly, fluid in the chamber <NUM> is obstructed or otherwise blocked from rising above the level of the sealing member <NUM>, and thereby prevented from entering the inlet <NUM> and the IV bag <NUM>. As such, the structure of the drip chamber device <NUM> as described herein is advantageous in preventing secondary fluid from entering the primary IV bag <NUM> and resultantly being underinfused to the patient. Furthermore, the convergent-divergent conical shape of the housing <NUM> is advantageous in that the walls of inner circumferential surface <NUM> guide motion of the valve member as it is translated proximally toward the top surface by the buoyant force. In particular, the first sidewall or sidewall portion <NUM> having the conical shape extending radially inward from the intermediate section <NUM> of the housing and tapering at the top end <NUM> may guide the path of the valve member <NUM> towards the sealing ring <NUM> and the central axis X (illustrated in <FIG>). Accordingly, the conical shape of the housing <NUM> is advantageous in ensuring that the valve member <NUM>, when subject to the buoyant force F and travels proximally towards the top end, may be guided towards the central portion of the chamber <NUM> where the sealing ring <NUM> is disposed.

<FIG> illustrates an operational state of the drip chamber device <NUM> where secondary fluid backflow into the drip chamber device <NUM> has ceased and the fluid in the drip chamber falls below the predetermined level, in accordance with some embodiments of the present disclosure. As depicted, as the secondary fluid ceases to backflow into the primary fluid line <NUM> and collect in the drip chamber device <NUM>, the level of the fluid in the chamber may decrease below the predetermined level. As the level of the fluid decreases, the buoyant force on the valve member is diminished and the valve member, with its mass subject to gravity forces may fall distally (downstream or downwards) until a point where the valve member is seated on the base plate as illustrated in <FIG>.

Accordingly, the various embodiments of the present disclosure are advantageous in providing a drip chamber device capable of preventing under-infusion of the secondary drug by blocking the secondary drug from entering into the primary IV bag <NUM>, as discussed previously. The drip chamber device of the various embodiments described herein is further advantageous as it minimizes the number of separate components of an IV set by replacing a check valve and a conventional drip chamber with the drip chamber device. As a result, cost of the IV set may be reduced. Additionally, the various embodiments of the present disclosure are advantageous in providing a drip chamber device which provides better sealing as the fluid level in the housing increases. Further advantageously, the drip chamber device of the various embodiments described herein may optionally be retrofit with existing IV pump devices, so there is no need for specialized components in order to make the drip chamber device compatible with existing pumps.

It is understood that the specific order or hierarchy of steps, or operations in the processes or methods disclosed are illustrations of exemplary approaches. Based upon implementation preferences or scenarios, 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. In some implementation preferences or scenarios, certain operations may or may not be performed. Some or all of the steps, operations, or processes may be performed automatically, without the intervention of a user. The accompanying method claims 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.

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.

Claim 1:
A drip chamber device (<NUM>), comprising:
A housing (<NUM>) having a top end (<NUM>) including an inlet (<NUM>), and a bottom end (<NUM>) including an outlet (<NUM>) disposed downstream of the inlet (<NUM>);
a chamber (<NUM>) defined by an inner circumferential surface (<NUM>) of the housing, the chamber (<NUM>) fluidly connecting the inlet (<NUM>) with the outlet (<NUM>), and the inner circumferential surface (<NUM>) having a first sidewall (<NUM>) extending radially outward and distally from the top end (<NUM>) of the housing and a second sidewall (<NUM>) extending radially inward and distally from the first sidewall (<NUM>) to the bottom end (<NUM>) of the housing; and
a valve member (<NUM>) disposed in the chamber (<NUM>) to move between (i) a closed state where fluid communication between the inlet (<NUM>) and the chamber (<NUM>) is blocked, and (ii) an open state where fluid communication between the inlet (<NUM>) and the chamber (<NUM>) is not blocked, based on a level of fluid within the chamber (<NUM>).