Patent Description:
Catheters are commonly used for a variety of infusion therapies. For example, catheters may be used for infusing fluids, such as normal saline solution, various medicaments, and total parenteral nutrition, into a patient. Catheters may also be used for withdrawing blood from the patient.

A common type of catheter is an over-the-needle peripheral intravenous ("IV") catheter (PIVC). As its name implies, the over-the-needle catheter may be mounted over an introducer needle having a sharp distal tip. A catheter assembly may include a catheter hub, the catheter extending distally from the catheter hub, and the introducer needle extending through the catheter. The catheter and the introducer needle may be assembled so that the distal tip of the introducer needle extends beyond the distal tip of the catheter with the bevel of the needle facing up away from skin of the patient. The catheter and introducer needle are generally inserted at a shallow angle through the skin into vasculature of the patient.

For blood withdrawal or collecting a blood sample from a patient, a blood collection container may be used. The blood collection container may include a syringe. Alternatively, the blood collection container may include a test tube with a rubber stopper at one end. In some instances, the test tube has had all or a portion of air removed from the test tube so pressure within the test tube is lower than ambient pressure. Such a blood collection container is often referred to as an internal vacuum or a vacuum tube. A commonly used blood collection container is a VACUTAINER® blood collection tube, available from Becton Dickinson & Company.

The blood collection container may be coupled to the catheter. When the blood collection container is coupled to the catheter, a pressure in the vein is higher than a pressure in the blood collection container, which pushes blood into the blood collection container, thus filling the blood collection container with blood. A vacuum within the blood collection container decreases as the blood collection container fills, until the pressure in the blood collection container equalizes with the pressure in the vein, and the flow of blood stops.

Unfortunately, as blood is drawn into the blood collection container, red blood cells may experience high shear stress and be susceptible to hemolysis due to the flow rate through and geometry of the blood collection system. Hemolysis may result in rejection and discard of a blood sample. The blood draw can also result in an area of local negative pressure at the catheter tip, which may lead to catheter tip collapse, vein collapse, or other complications that prevent or restrict blood from filling the blood collection container. Furthermore, blood spillage during and/or after blood draw may occur.

Document <CIT>(A1) describes an adapter designed for use in medical applications, particularly for connecting a catheter assembly to a blood collection device. The adapter includes a distal end for coupling to the catheter and a proximal end with a connector for attaching to the blood collection device. Between these ends, a fluid pathway is incorporated, which includes a non-linear segment which can take various forms, such as a coil or an S-shape.

Document <CIT>(A1) describes a device and method for evaluating blood coagulation. The device consists of a channel through which blood is drawn by a vacuum-tube. In one section of the channel, the blood is subjected to shear stress that is designed to mimic physiological conditions.

In <CIT>(B2), a device that combines blood collection and fluid administration functionalities through a single needle insertion is disclosed. The device features a tubing segment that connects to a cannula inserted into a vein, with branches for blood collection and fluid administration.

The claimed invention lies in the flow restriction device of appended claim <NUM>. Further embodiments are given in the appended dependent claims.

The present disclosure provides a flow restriction device, comprising: a male luer connector portion defining a cavity and a first lumen in fluid-flow continuity with the cavity; and a female luer connector portion defining a second lumen and an extension in fluid-flow continuity with the second lumen, the extension comprising: a first end; a second end; an outer surface; and a channel defined on the outer surface, wherein the channel is helically disposed around the outer surface of the extension and extends between the first and second ends, the extension is configured to be at least partially disposed within the cavity, and the channel and the inner surface of the cavity define a fluid passage in fluid-flow continuity with the first lumen and the second lumen.

In some instances, the present disclosure provides a flow restriction device, comprising: a male luer connector portion defining a first cavity and a first lumen in fluid-flow continuity with the first cavity; and a female luer connector portion defining a second lumen and an extension, wherein the extension defines a second cavity in fluid-flow continuity with the second lumen, the extension comprising: a first end; a second end; an outer surface; and a channel defined on the outer surface, wherein the channel is helically disposed around the outer surface of the extension and extends between the first and second ends, the extension is configured to be at least partially disposed within the first cavity, and the channel and the inner surface of the first cavity define a fluid passage in fluid-flow continuity with the first cavity and the second cavity.

In some aspects, the present disclosure provides a peripheral intravenous catheter assembly configured to limit hemolysis during drawing of blood from a patient, comprising: a catheter hub having a proximal end and a distal end; a fluid collection device; and a flow restriction device, comprising: a male luer connector portion defining a cavity and a first lumen in fluid-flow continuity with the cavity and the catheter hub; and a female luer connector portion defining a second lumen in fluid-flow continuity with the fluid collection device and an extension in fluid-flow continuity with the second lumen, the extension comprising: a first end; a second end; an outer surface; and a channel defined on the outer surface, wherein the channel is helically disposed around the outer surface of the extension and extends between the first and second ends, the extension is configured to be at least partially disposed within the cavity, and the channel and the inner surface of the cavity define a fluid passage in fluid-flow continuity with the first lumen and the second lumen.

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.

Blood draw via a vascular access device has drawn increasing attention attributed to minimized needle sticks and improved operation efficiency as compared with traditional blood draw methods with venipuncture. Current blood draw using a peripheral intravenous catheter (PIVC) has seen some challenges, one of the most critical is hemolysis related blood quality. In particular, with currently existing PIVC products in the market, along with the standard connection (such as a short extension set and a needleless connector), and blood collection devices (such as a Vacutainer), the shear stress exerted onto red blood cells often causes hemolysis.

Various embodiments of the present disclosure are directed to providing systems and methods to address hemolysis in PIVC blood draw with a hemolysis reduction accessory (also referred to herein as a flow restriction device), such as a connector, which is attached to the PIVC and serves as a flow restrictor to reduce risk of hemolysis. The hemolysis-reduction accessory is advantageously compatible with PIVC placement and does not necessitate change to any of the existing operations. The hemolysis-reduction accessory of the various embodiments described herein is potentially applicable to a wide variety of PIVC products, and compatible with existing blood collection devices and infusion disposables.

Various embodiments of the present disclosure focus on effective flow restriction with the add-on hemolysis-reduction accessory (also referred to herein as a flow restriction device) that regulates the overall flow rate of the entire fluid path as blood travels through. The flow restriction device can be either assembled with the PIVC or co-packaged with the PIVC. The clinician may connect a blood collection device to the port of the accessory and can then draw blood to the intended volume. After blood draw, the clinician may disconnect and discard the flow restriction device and the blood collection device together. As such, this flow restriction device can be either for single blood draw or stay inline throughout indwell.

The flow restriction devices and associated blood collection systems of the various embodiments described herein additionally provide further advantages over currently existing blood collection systems. For example, add-on flow restriction devices described herein reduce hemolysis while allowing blood to be drawn through an already-placed PIVC. Further, the flow restriction devices described herein are compatible with PIVC connections and allow for seamless blood draw at insertion. Additionally, since the flow restriction devices are an add-on which can be easily incorporated without any changes to existing PIVC, there is minimal impact to clinical setting and operations.

<FIG> illustrates a vascular access device <NUM> including a peripheral intravenous catheter (PIVC) assembly <NUM> that includes a connector or flow restriction device <NUM>, in accordance with some embodiments of the present disclosure. The flow restriction device <NUM> may be configured to facilitate connections for components of the vascular access device <NUM> and reduce a likelihood of hemolysis during blood collection using the vascular access device <NUM>. In some embodiments, the vascular access device <NUM> may include a catheter assembly <NUM>. The catheter assembly <NUM> may include a catheter hub <NUM>, which may include a distal end <NUM>, a proximal end <NUM>, and a lumen extending through the distal end and the proximal end. The catheter assembly <NUM> may further include a catheter <NUM>, which may be secured within the catheter hub <NUM> and may extend distally from the distal end <NUM> of the catheter hub <NUM>. In some embodiments, the catheter assembly <NUM> may be a peripheral intravenous catheter (PIVC).

In some embodiments, the catheter assembly <NUM> may include or correspond to any suitable catheter assembly <NUM>. In some embodiments, the catheter assembly <NUM> may be integrated and include an extension tube <NUM>, which may extend from and be integrated with a side port <NUM> of the catheter hub <NUM>. A non-limiting example of an integrated catheter assembly is the BD NEXIVA™ Closed IV Catheter system, available from Becton Dickinson and Company. In some embodiments, a proximal end of the extension tube <NUM> may be coupled to an adapter, such as, for example, a Y-adapter <NUM>. In some embodiments, the flow restriction device <NUM> may be fluidly coupled to the Y-adapter <NUM>.

In some embodiments, the catheter assembly <NUM> may be non-integrated and may not include the extension tube <NUM>. In these and other embodiments, the flow restriction device <NUM> may be configured to couple to the proximal end <NUM> of the catheter hub <NUM> or another suitable portion of the catheter assembly <NUM>. In some embodiments, the flow restriction device <NUM> may be coupled directly to the catheter assembly <NUM>, eliminating the extension tube <NUM> and providing a compact catheter system.

<FIG> illustrates a perspective view of the flow restriction device <NUM>, in accordance with some embodiments of the present disclosure. <FIG> illustrates an exploded view of the flow restriction device <NUM> of <FIG>, in accordance with some embodiments of the present disclosure. <FIG> illustrates an exploded cross-sectional view of the flow restriction device <NUM> of <FIG>, in accordance with some embodiments of the present disclosure.

As illustrated in <FIG>, and with continued reference to <FIG>, the flow restriction device <NUM> includes a male luer connector portion <NUM> configured to couple to the catheter assembly <NUM>. The male luer connector portion <NUM> has an internal surface defining a lumen <NUM> of the male luer connector portion <NUM>. In some embodiments, a distal end of the male luer connector portion <NUM> can be coupled to the catheter assembly <NUM>. The lumen <NUM> is in fluid-flow continuity with a cavity <NUM> defined by the body <NUM> of the male luer connector portion <NUM>.

The flow restriction device <NUM> further includes a female luer connector portion <NUM> disposed proximally to the male luer connector portion <NUM>. The female luer connector portion <NUM> may be configured to couple to fluid collection device <NUM> (e.g., a blood collection device). For example, the female luer connector portion <NUM> may be integrated with the blood collection device <NUM> or monolithically formed with the blood collection device <NUM> as a single unit or piece. As another example, the female luer connector portion <NUM> may be in the form of a female luer connector or another suitable connector, which may be coupled with a male luer portion of the blood collection device <NUM>. The female luer connector portion <NUM> includes an internal surface defining a lumen <NUM> extending therethrough for coupling to the male luer portion of the blood collection device <NUM>. In some embodiments, a proximal end of the female luer connector portion <NUM> can be coupled to the blood collection device <NUM>. Optionally, a threaded portion <NUM> of the female luer connector portion <NUM> can be utilized to engage the female luer connector portion <NUM> to a corresponding male luer portion.

In the depicted example, the body <NUM> of the male luer connector portion <NUM> is coupled to the body <NUM> of the female luer connector portion <NUM> to allow fluid-flow continuity between the lumen <NUM> and the lumen <NUM> of the flow restriction device <NUM> and form a common housing.

In the depicted example, the female luer connector portion <NUM> includes an extension <NUM> to control fluid flow between the lumens <NUM>, <NUM> and reduce hemolysis through the total blood flow pathway from PIVC to blood collection device <NUM>. As illustrated, the extension <NUM> is disposed within the cavity <NUM> formed by the male luer connector portion <NUM>. As illustrated, the extension <NUM> directs fluid flow between the lumens <NUM> and <NUM> of the male luer connector portion <NUM> and the female luer connector portion <NUM>, respectively while inducing a resistance to the fluid flow <NUM>. By inducing a resistance to the fluid flow, the rate of fluid flow through the assembly from PIVC to blood collection device is reduced <NUM>. Reducing the flow rate of a fluid, such as blood, through the assembly can reduce the hemolysis index of the blood.

According to embodiments herein, the extension <NUM> defines a groove or channel <NUM> that directs fluid flow from a distal end <NUM> of the extension <NUM> to a proximal end <NUM> of the extension <NUM>. As illustrated, the channel <NUM> is defined along an outer surface of the extension <NUM>.

Accordingly, when the extension <NUM> is positioned within the cavity <NUM> of the male luer connector portion <NUM>, at least a portion of the outer surface of the extension <NUM> engages against an inner surface of the cavity <NUM> to permit the channel <NUM> and the inner surface of the cavity <NUM> to cooperatively define a fluid passage therebetween. The defined fluid passage extends along a path between the distal end <NUM> and the proximal end <NUM> of the extension <NUM> to reduce a rate of fluid flow across the extension <NUM>. In some embodiments, the groove or channel <NUM> can be formed on an inner surface of the body <NUM> such that engagement with the outer surface of the extension <NUM> forms a fluid pathway. In some embodiments, the groove or channel <NUM> can extend along one or both of the inner surface of the body <NUM> and the outer surface of the extension <NUM> such that when the body <NUM> receives the extension <NUM>, a fluid pathway is formed to conduct fluid between the body <NUM> and the extension <NUM>.

In the depicted example, fluid flow can pass from the lumen <NUM> of the male luer connector portion <NUM> to the distal end <NUM> of the extension <NUM> via the cavity <NUM>. In some embodiments, fluid can flow from the proximal end <NUM> of the extension <NUM> to the lumen <NUM> of the female luer connector portion <NUM> via a port <NUM> formed through the extension <NUM>. In some embodiments, the port <NUM> can allow fluid flow between the proximal end <NUM> of the extension <NUM> and/or the channel <NUM> into a cavity <NUM> formed within the extension <NUM>. The cavity <NUM> formed within the extension <NUM> can be separated from the cavity <NUM> of the male luer connector portion <NUM> by the body of the extension <NUM>. As illustrated, the cavity <NUM> can be in fluid-flow continuity with the lumen <NUM>. Therefore, in some embodiments, fluid flow can pass from the proximal end <NUM> of the extension <NUM> to the lumen <NUM> via a port <NUM> and the cavity <NUM>.

Therefore, in some embodiments, the channel <NUM> (in conjunction with the inner surface of the cavity <NUM>) can direct fluid flow from the male luer connector portion <NUM> into the fluid collection device <NUM> via the female luer connector portion <NUM>. As depicted, the channel <NUM> may provide a fluid pathway from the catheter assembly <NUM> to the fluid collection device <NUM> via the flow restriction device <NUM>. For example, in some embodiments, a leg <NUM> of the Y-adapter <NUM> may be coupled to the flow restriction device <NUM>. The leg <NUM> of Y-adapter <NUM> may include a lumen into which the distal end of the male luer connector portion <NUM> may be coupled. The Y-adapter <NUM> may provide fluid-flow continuity between the flow restriction device <NUM> via a connector <NUM>, which is depicted as a needleless connector, and the channel <NUM> with the catheter assembly <NUM>, for example, via the extension tubing <NUM>. Accordingly, the channel <NUM> may define a fluid pathway with a helical, spiral, extended, or otherwise indirect path (as discussed below) through which fluid entering the flow restriction device <NUM> from the catheter assembly <NUM>, may flow through the flow restriction device <NUM> for collection in the fluid collection device <NUM>. For example, where blood is being withdrawn or collected from a patient, the medical fluid may be blood, and the fluid collection device <NUM> may be a blood collection device. In some embodiments, the blood collection device may be a blood collection tube holder such as the BD Vacutainer ® LuerLok™ Access Device (LLAD). Accordingly, during blood collection or withdrawal from the patients, the blood sample may flow from the distal end of the male luer connector portion <NUM> into the LLAD <NUM> via the flowpath or channel <NUM>.

In some embodiments, the extension <NUM> can define a longitudinal axis that extends through the distal and proximal ends <NUM>, <NUM>. The channel <NUM> spans between the distal and proximal ends <NUM>, <NUM> of the extension <NUM>, and is configured to spiral or helically extend along the longitudinal axis. Because the path spirals about the longitudinal axis, the channel <NUM> extends indirectly between the distal and proximal ends <NUM>, <NUM> of the extension <NUM>. The indirect path between the distal and proximal ends <NUM>, <NUM> of the extension <NUM> can have a length that is greater than a distance between the distal and proximal ends <NUM>, <NUM> of the extension <NUM>. In some instances, the pitch and the angle of the turns of the helical channel <NUM> can be optimized to reduce the volumetric flow rate of a fluid, e.g., blood, moving through the channel <NUM> by inducing resistance to the fluid. Since the decreased blood flow rate results in a reduction in shear stress experienced by the red blood cells, the risk of hemolysis during blood collection may advantageously be reduced.

The flow restriction device <NUM> of the various embodiments described herein is advantageous over currently existing PIVC blood collection systems. For example, during blood draws with currently existing PIVCs, blood cells may experience supraphysiologic levels of shear stress as they flow from the distal end to the proximal end of the blood collection systems. Subjecting red blood cells to supraphysiologic levels of shear stress is considered a major source of mechanical damage and hemolysis of red blood cells The diameter and effective length of the channel <NUM> may facilitate increased flow resistance within the vascular access system to reduce the flow rate and reduce shear stress experienced by the red blood cells <NUM>. For example, the minimized diameter and elongated effective length of the channel <NUM> may provide increased resistance to flow of the blood <NUM> and thereby decrease blood flow rate within the PIVC, device, and blood collection device assembly <NUM>. Since the decreased blood flow rate causes a reduction in shear stress experienced by the red blood cells <NUM>, the risk of hemolysis during blood collection may advantageously be reduced. Further, the geometry of the channel <NUM> can reduce the amount of blood wasted by currently existing PIVC blood collection systems.

Further, the flow restriction device <NUM> can reduce hemolysis without the use of active devices such as valves or other flow control devices. In some applications, the configuration of the flow restriction device <NUM> as described herein can minimize flushing of the vascular access device <NUM>, minimize dead volume, and facilitate a compact design. Further, the configuration of the flow restriction device <NUM> can facilitate ease of manufacturing compared to certain prior art designs. For example, in some applications, the male luer connector portion <NUM> and the female luer connector portion <NUM> can be joined together followed by ultrasonic welding to form the flow restriction device <NUM>.

Claim 1:
A flow restriction device (<NUM>), comprising:
a male luer connector portion (<NUM>) defining a body portion (<NUM>) and a first lumen (<NUM>) in fluid-flow continuity with the body portion; and
a female luer connector portion (<NUM>) defining a second lumen (<NUM>) and an extension (<NUM>) in fluid-flow continuity with the second lumen, wherein the extension comprises:
a first end (<NUM>);
a second end (<NUM>);
an outer surface; and
a channel (<NUM>) defined on the outer surface, wherein the channel is helically disposed around the outer surface of the extension and extends between the first and second ends, the extension is configured to be at least partially disposed within the body portion, and the channel and the inner surface of the body portion define a fluid passage in fluid-flow continuity with the first lumen and the second lumen, characterised in that an end of the body portion of the male luer connector portion is configured to be coupled to the female luer connector portion within a body portion (<NUM>) of the female luer connector portion.