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 are in a high shear stress state and susceptible to hemolysis due to a high initial pressure differential between the vein and the blood collection container. Hemolysis may result in rejection and discard of a blood sample. The high initial pressure differential can also result in 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 commonly occurs.

<CIT> discloses an adapter including a distal end, which may be configured to couple to a catheter assembly. The adapter may include a proximal end, which may include a proximal connector configured to couple to a blood collection device. The adapter may include a fluid pathway disposed between the distal end and the proximal end, wherein the fluid pathway includes a non-linear portion. The non-linear portion may form a coil shape, an S-shape, or another suitable shape.

The invention is defined in the independent claim <NUM>.

Preferable embodiments are further laid out in the dependent claims. The present disclosure provides a flow restriction device, comprising: a housing defining a first lumen, a second lumen, and a cavity disposed between the first lumen and the second lumen; and an insert body disposed within the cavity, the insert body comprising: a first end; a second end; a longitudinal axis extending through the first and second ends; an outer surface; and a channel defined on the outer surface, wherein the channel extends between the first and second ends, the channel comprising a first portion that extends in a first direction away from the longitudinal axis and a second portion that extends in a second direction toward the longitudinal axis, and the channel and an inner surface of the cavity define a fluid passage in fluid communication 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 lumen; a female luer connector portion defining a second lumen, wherein the male luer portion connector and the female luer connector portion cooperatively define a cavity; and an insert body disposed within the cavity, the insert body comprising: a first end; a second end; an outer surface; and a serpentine channel defined on the outer surface, wherein the channel extends between the first and second ends and the channel and an inner surface of the cavity define a fluid passage in fluid communication with the first lumen and the second lumen.

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 housing defining a first lumen, a second lumen, and a cavity disposed between the first lumen and the second lumen, wherein the first lumen is in fluid communication with the catheter hub and the second lumen is in fluid communication with the fluid collection device; and an insert body disposed within the cavity, the insert body comprising: a first end; a second end; an outer surface; and a tortuous channel defined on the outer surface, wherein the channel extends between the first and second ends and the channel and an inner surface of the cavity define a fluid passage in fluid communication 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.

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 blood cells tends to be on the verge of hemolyzing.

Various embodiments of the present disclosure are directed to providing systems and non claimed 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 cells travel 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 allow for hemolysis-reduction function to be integrated for PIVC blood draw. Further, the flow restriction devices described herein are compatible with PIVC placement 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 a 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>, in some embodiments, the flow restriction device <NUM> may include a male luer connector portion <NUM> configured to couple to the catheter assembly <NUM>. The male luer connector portion <NUM> may have 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>. In some embodiments, the lumen <NUM> is in fluid communication with a cavity <NUM> defined by the body <NUM> of the male luer connector portion <NUM>.

In some embodiments, the flow restriction device <NUM> may further include 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> may include 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 some embodiments, the lumen <NUM> is in fluid communication with a cavity <NUM> defined by the body <NUM> of the female luer connector portion <NUM>.

In the depicted example, the body <NUM> of the male luer connector portion <NUM> can be coupled to the body <NUM> of the female luer connector portion <NUM> to allow fluid communication between the lumen <NUM> and the lumen <NUM> of the flow restriction device <NUM> and form a common housing. As illustrated, the cavity <NUM> of the male luer connector portion <NUM> can be placed in fluid communication with the cavity <NUM> of the female luer connector portion <NUM> to form a common cavity. Accordingly, the lumen <NUM> of the male luer connector portion <NUM> can be in fluid communication with the lumen <NUM> of the female luer connector portion <NUM> through the common cavity formed via the respective cavities <NUM>, <NUM>.

In the depicted example, an insert body <NUM> can be disposed within the common cavity formed by the male luer connector portion <NUM> and the female luer connector portion <NUM> to control fluid flow between the lumens <NUM>, <NUM> and reduce hemolysis through the flow restriction device <NUM>. As illustrated, the insert body <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 as it moves across the insert body <NUM>. By inducing a resistance to the fluid flow, the rate of fluid flow is reduced as the fluid moves across the insert body <NUM>. Reducing the flow rate of a fluid, such as blood, through the flow restriction device <NUM> can reduce the hemolysis index of the blood.

In some embodiments, an insert body <NUM> defines a channel <NUM> that directs fluid flow from a distal end <NUM> of the insert body <NUM> to a proximal end <NUM> of the insert body <NUM>. As illustrated, the channel <NUM> can be defined along an outer surface of the insert body <NUM>. Accordingly, when the insert body <NUM> is positioned within the common cavity defined by the male luer connector portion <NUM> and the female luer connector portion <NUM>, at least a portion of the outer surface of the insert body <NUM> can engage against an inner surface of the common cavity to permit the channel <NUM> and the inner surface of the common cavity to cooperatively define a fluid passage therebetween. The defined fluid passage can extend along a path between the distal end <NUM> and the proximal end <NUM> of the insert body <NUM> to reduce a rate of fluid flow across the insert body <NUM>. In some embodiments, the channel <NUM> may be defined on an inner surface of the body <NUM>, such that when the insert body <NUM> is received within the connector portion <NUM>, a pathway is formed by engagement of the outer surface of the insert body <NUM> and the inner surface of the body <NUM>. In some embodiments, the channel <NUM> is an open channel on either or both of the insert body <NUM> and the connector portion <NUM> body <NUM> that is closed to form a passageway by the engagement of the inner surface of the body <NUM> and the outer surface of the insert body <NUM>.

Therefore, in some embodiments, the channel <NUM> (in conjunction with the inner surface of the common cavity) 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 fluidly communicate the catheter assembly <NUM> with 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 fluidly communicate 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 serpentine, tortuous, 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 luer lock 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 insert body <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 insert body <NUM>, and is configured to extend in more than one direction along a path between the distal and proximal ends <NUM>, <NUM>. Because the path extends in more than one direction, the channel <NUM> extends indirectly between the distal and proximal ends <NUM>, <NUM> of the insert body <NUM>. The indirect path between the distal and proximal ends <NUM>, <NUM> of the insert body <NUM> can have a length that is greater than a distance between the distal and proximal ends <NUM>, <NUM> of the insert body <NUM>.

As illustrated, the channel <NUM> can be disposed along a serpentine, tortuous, or turning path. In other words, the channel <NUM> can include a first portion <NUM> that extends in a first direction away from the longitudinal axis and a second portion <NUM> that extends in a second direction toward the longitudinal axis. Further, the channel <NUM> can include additional portions that extend toward and away from the longitudinal axis. The change in direction of the channel <NUM> between the distal and proximal ends <NUM>, <NUM> of the insert body <NUM> can be configured by an angle between one or more portion of the channel <NUM>. In some instances, the channel <NUM> can have a change in direction by an angle between approximately <NUM> degrees and approximately <NUM> degrees. The changes in direction of the channel <NUM> can form a line that represents a periodic wave, such as a sinusoidal wave. The changes in direction of the channel <NUM> are optimized to reduce pressure of a fluid, e.g., blood, moving through the channel <NUM> by inducing resistance to the fluid. Since the decreased blood flow rate causes a reduction in shear stress experienced by the red blood cells of the blood, a risk of hemolysis during blood collection may advantageously be reduced. In some embodiments, the channel <NUM> can have a diameter in the range of about <NUM> millimeters to about <NUM> millimeters (about <NUM> inches to <NUM> inches). In some embodiments, the length of the channel <NUM> can be of about <NUM> millimeters to about <NUM> millimeters (about <NUM> inches to about <NUM> inches).

As illustrated, the path of the channel <NUM> can be disposed or otherwise confined to a portion of the outer surface of the insert body <NUM>. For example, the path of the channel <NUM> may extend within an arc defined by the cross-section of the cylindrical insert body <NUM>. In some embodiments, the path of the channel <NUM> can extend within an <NUM>-degree arc defined by the cross-section of the cylindrical insert body <NUM>. In some embodiments, the path of the channel <NUM> can extend within a <NUM>-degree arc defined by the cross-section of the cylindrical insert body <NUM>.

The flow restriction device <NUM> of the various embodiments described herein is advantageous over currently existing blood collection systems. For example, during blood draw with currently existing blood draw devices, blood cells may experience wall shear stress as they flow from the distal end to the proximal end of the blood collection systems. Wall shear stress on blood cells is considered a major source of mechanical damage to blood cells causing hemolysis of the blood cells. The diameter and effective length of the channel <NUM> may facilitate increased flow resistance within the vascular access system to distribute the pressure differential and reduce shear stress experienced by the red blood cells of the blood <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 flow restriction device <NUM>. Since the decreased blood flow rate causes a reduction in shear stress experienced by the red blood cells of the blood <NUM>, a 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 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 insert body <NUM> can be press fit within the male luer connector portion <NUM> followed by ultrasonic welding of the female luer connector portion <NUM> to form the flow restriction device <NUM>.

Claim 1:
A flow restriction device (<NUM>), comprising: a housing defining a first lumen (<NUM>), a second lumen (<NUM>), and a cavity (<NUM>) disposed between the first lumen and the second lumen; and an insert body (<NUM>) disposed within the cavity, the insert body comprising: a first end (<NUM>); a second end (<NUM>); a longitudinal axis extending through the first and second ends; an outer surface; and
a channel (<NUM>) defined on the outer surface, wherein the channel extends between the first and second ends, the channel comprising a first portion (<NUM>) that extends in a first direction away from the longitudinal axis, when the channel is seen from the top in a direction perpendicular to the longitudinal axis and a second portion (<NUM>) that extends in a second direction toward the longitudinal axis, when the channel is seen from the top in a direction perpendicular to the longitudinal axis and the channel and an inner surface of the cavity define a fluid passage in fluid communication with the first lumen and the second lumen,
characterised in that the second portion is disposed at an angle between <NUM> degrees and <NUM> degrees relative to the first portion.