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 a compressible hose being arranged in a housing, the ends of which are seated on pipe sections. Between the pipe sections there is a capillary tube with a narrow capillary channel. When a pressure piece is pressed in the transverse direction against the hose, the hose is flattened, creating two lateral bypass channels that lead around the capillary tube. In this way, in addition to the normally throttled flow, a higher flow can be achieved temporarily by pressing in the pressure piece.

Preferable embodiments are further laid out in the dependent claims.

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 blood cells tends to be on the verge of hemolyzing.

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) which is pre-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 flow restriction device <NUM>, in accordance with some embodiments of the present disclosure. The flow restriction device <NUM> may be configured to 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.

2A illustrates a perspective view of the flow restriction device <NUM>, in accordance with some embodiments of the present disclosure. <FIG> illustrates an exploded perspective 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>, 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 <NUM> defining a lumen <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 <NUM> defining a lumen <NUM> extending therethrough for coupling to the male luer portion of the blood collection device <NUM>. The lumen <NUM> of the female luer connector portion <NUM> may be fluidly connected to the lumen <NUM> of the male luer connector portion <NUM> via a tube <NUM> of the flow restriction device <NUM>, as shall be described below.

In the depicted example, the flow restriction device <NUM> includes a tube <NUM> extending longitudinally therethrough and fluidly communicated with the lumens <NUM> and <NUM> of the male luer portion <NUM> and the female luer portion <NUM>, respectively. The tube <NUM> may define a micro-channel <NUM> along which a fluid flows from the male luer connector portion <NUM> into the fluid collection device <NUM> via the female luer connector portion <NUM>. As depicted, the tube <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 tube <NUM> with the catheter assembly <NUM>, for example, via the extension tubing <NUM>. Accordingly, the micro-channel <NUM> may define a fluid pathway with a reduced, small, or micro-sized diameter (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 micro-channel <NUM> defined by the tube <NUM>.

In some embodiments, micro-channel <NUM> defined by the tube <NUM> may be an elongate, thin channel having a small, reduced, or micro-sized diameter. According to the present invention, the tube <NUM> which defines the flowpath or micro-channel along which fluid may flow from the male luer connector portion <NUM> into the fluid collection device <NUM>, has a diameter in the range of <NUM> millimeters and <NUM> millimeters (a twenty thousandth to twenty-five thousandth of an inch). In some embodiments, the length of the micro-channel <NUM> may range from <NUM> millimeters to about <NUM> millimeters (<NUM> to <NUM> inches). Accordingly, during blood collection or withdrawal from the patient, the blood <NUM> may flow into the blood collection device <NUM> via the flowpath or micro-channel defined by the micro-channel <NUM> having minimal diameter. 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 micro-channel <NUM> having minimal diameter 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 of the micro-channel <NUM> may provide increased resistance to flow of the blood <NUM> and thereby decrease blood flow rate within the flow resistance 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 micro-channel <NUM> can reduce the amount of blood wasted by currently existing blood collection systems.

In accordance with various embodiments of the present disclosure, the flow restriction device <NUM> may further include a body portion <NUM> overmolded the tube <NUM> and extending between the male luer <NUM> portion and the female luer portion <NUM>.

According to various embodiments of the present disclosure, an outer surface <NUM> of the body portion <NUM> may include a plurality of laterally extending ribs disposed about and surrounding a longitudinal axis of the body portion <NUM>. As depicted, the plurality of laterally extending ribs may be spaced apart from each other along the longitudinal axis X between the female luer connector portion <NUM> and the male luer connector portion <NUM>. In some embodiments, the outer surface <NUM> may further include at least one longitudinally extending rib disposed along the longitudinal axis and extending from the male luer connector portion <NUM> to the female luer connector portion <NUM>. In some embodiments, as illustrated in <FIG>, the body portion <NUM> may include a pair of longitudinally extending ribs disposed at opposing sides of the body portion <NUM>. As depicted, the longitudinally extending rib may be disposed transverse to and may interconnect each of the laterally extending ribs. The plurality of laterally extending ribs and the one or more longitudinally extending ribs may thus form a grid or matrix shape surrounding the body portion <NUM>.

The grid or matrix shape surrounding the body portion <NUM> may advantageously provide additional or enhanced structural integrity or rigidity as compared with currently existing connectors for blood collection systems. For example, in some embodiments, the grid or matrix shape of the laterally extending ribs and the longitudinally extending ribs surrounding the body portion <NUM> may provide increased rigidity between the male luer connector portion <NUM> and the female luer connector portion <NUM> of the flow restriction device <NUM>, thereby making the flow restriction device <NUM> less susceptible to bending or twisting forces. The aforementioned configuration is advantageous in that the enhanced rigidity of the flow restriction device <NUM> makes it less flexible thereby decreasing the possibility of blood spillage due to accidental or inadvertent bending or twisting of the flow control device <NUM>. The aforementioned configuration of the flow restriction device with the laterally extending ribs and the longitudinally extending ribs surrounding the body portion <NUM> may further be advantageous in providing a surface on the body portion that is easier to grip than would a more uniform surface of the body portion <NUM> be to grip.

As described herein, the body portion <NUM> is overmolded over the tube <NUM> to provide a gripping surface for a clinician. In some embodiments, the body portion <NUM> can also extend over portions of the male luer connector portion <NUM> and/or the female luer connector portion <NUM>. Advantageously, by overmolding the body portion <NUM>, the flow control device <NUM> can provide a gripping surface for the clinician while reducing manufacturing complexity of the flow control device <NUM>. For example, the body portion <NUM> can be molded directly on top of the tube <NUM> to create a single piece include the tube <NUM> and the body portion <NUM>. Advantageously, the body portion <NUM> can define a simplified profile to simplify the overmolding process. In some embodiments, the body portion <NUM> can utilize a polymeric or elastomeric material. The aforementioned configuration in which the flow restriction device <NUM> is formed with an overmolded body simplifies the manufacturing process while allowing for robust construction of the flow restriction device <NUM>.

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 flow restriction device (<NUM>), comprising: a male luer connector portion (<NUM>) defining a first lumen (<NUM>); a female luer connector portion (<NUM>) defining a second lumen (<NUM>);
a tube (<NUM>) defining a third lumen (<NUM>), wherein the third lumen is in fluid communication with the first lumen and the second lumen, and the third lumen having a diameter between <NUM> millimeters and <NUM> millimeters (<NUM> inches and <NUM> inches); and
an overmolded body portion (<NUM>) formed around the tube.