Patent Description:
A common type of catheter is an over-the-needle peripheral intravenous ("IV") catheter. 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. As the blood collection container fills, a pressure differential between the vein and the blood collection container decreases, and filling of the blood collection container with blood slows significantly.

An adapter having the features defined within the preamble of claim <NUM> is described in <CIT>.

An adapter according to the invention is defined by the features of independent claims <NUM> and <NUM>. Preferred embodiments are defined within dependent claims.

The present disclosure relates generally to an adapter configured to reduce a likelihood of hemolysis during blood collection using a vascular access device, as well as related blood collection sets, systems, and methods. In some embodiments, the adapter may include a distal end, which may be configured to couple to a catheter assembly. In some embodiments, the adapter may include a proximal end, which may include a proximal connector configured to couple to a blood collection device. In some embodiments, 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.

In some embodiments, the non-linear portion may form a coil shape, an S-shape, or another suitable shape. In some embodiments, the non-linear portion may extend through a tube. In some embodiments, the adapter may include a lumen, which may extend through the distal end of the adapter and the proximal end of the adapter. In some embodiments, the tube may be disposed within the lumen. In some embodiments, the adapter may include a middle portion disposed between the distal end and the proximal end. In some embodiments, the middle portion may surround the tube.

In some embodiments, the distal connector may include a male luer threaded connector, a male luer slip connector, a blunt cannula, or another suitable connector. In some embodiments, the proximal connector may include a female luer connector. In some embodiments, the proximal end may be coupled to a blood collection device. For example, the proximal end may be integrated with the blood collection device or monolithically formed with the blood collection device as a single unit. As another example, the proximal end may include the female luer connector, which may be coupled with a male luer connector of the blood collection device.

In some embodiments, the blood collection device may include a syringe. In some embodiments, the blood collection device may include a needle configured to pierce a seal of an evacuated blood collection tube. In these and other embodiments, the blood collection device may include a cylindrical holder, which may extend around the needle and may be configured to receive the evacuated blood collection tube.

It is to be understood that both the foregoing general description and the following detailed description are examples and explanatory and are not restrictive. It should be understood that the various embodiments are not limited to the arrangements and instrumentality shown in the drawings. It should also be understood that the embodiments may be combined, or that other embodiments may be utilized and that structural changes, unless so claimed, may be made without departing from the scope of the various embodiments of the present disclosure. The following detailed description is, therefore, not to be taken in a limiting sense.

Referring now to <FIG>, an adapter <NUM> is illustrated, according to some embodiments. In some embodiments, the adapter <NUM> may be configured to reduce a likelihood of hemolysis during blood collection using a vascular access device. In some embodiments, the vascular access device may include a catheter assembly. In some embodiments, the adapter <NUM> may include a distal end <NUM>, which may include a distal connector <NUM> configured to couple to the catheter assembly. In some embodiments, the distal connector <NUM> may include a male luer threaded connector, as illustrated in <FIG>, or another suitable connector.

In some embodiments, the catheter assembly may include a catheter hub, which may include a distal end, a proximal end, and a lumen extending through the distal end and the proximal end. In some embodiments, the catheter assembly may include a catheter, which may be secured within the catheter hub and may extend distally from the distal end of the catheter hub. In some embodiments, the catheter may include a peripheral intravenous catheter (PIVC), a peripherally inserted central catheter (PICC), or a midline catheter.

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

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

In some embodiments, the adapter <NUM> may include a proximal end <NUM>, which may include a proximal connector <NUM> configured to couple to a blood collection device. In some embodiments, the proximal connector <NUM> may include a female luer connector or another suitable connector. In some embodiments, the adapter <NUM> may include a fluid pathway <NUM> disposed between the distal end <NUM> and the proximal end <NUM>. In some embodiments, fluid within the fluid pathway <NUM> may flow through the distal end <NUM> and/or the proximal end <NUM>. In some embodiments, the fluid within the fluid pathway <NUM> may flow through the proximal end <NUM> in response to opening of a septum <NUM> disposed within the proximal end <NUM>. In some embodiments, the septum <NUM> may open in response to coupling of the blood collection device to the proximal end <NUM> of the adapter <NUM>. In some embodiments, the septum <NUM> may include any suitable septum and may be different from the septum <NUM> illustrated. In some embodiments, the septum <NUM> may include an accordion-like septum <NUM> that may open when compressed in a distal direction.

In some embodiments, the fluid pathway <NUM> may include a non-linear portion <NUM>. Blood cells may experience shear stress as they flow through the fluid pathway <NUM>. The maximum shear stress is along the wall of the blood cell, or wall shear stress. Wall shear stress on blood cells is considered a major source of mechanical damage to blood cells. In some embodiments, the non-linear portion may facilitate increased flow resistance within the vascular access system to distribute the pressure differential and reduce shear stress experienced by red blood cells.

In some embodiments, the non-linear portion <NUM> may form a coil shape, an S-shape, or another suitable shape. As illustrated in <FIG>, in some embodiments, the non-linear portion <NUM> may include the coil shape, which may include a spiral. In some embodiments, no fluid flowing through the non-linear portion may flow in a straight line. In some embodiments, the non-linear portion <NUM> may increase a length of the fluid pathway <NUM> through the adapter <NUM> and thereby may increase flow resistance and decrease blood flow within the adapter <NUM>. In these embodiments, a risk of hemolysis during blood collection may be reduced.

In some embodiments, a length of the fluid pathway <NUM> of the adapter <NUM> may be selected based on one or more of the following: a gauge and/or length of the catheter, a configuration of the catheter assembly configuration, or a clinical setup. In some embodiments, the fluid pathway <NUM> may include a length L. In some embodiments, the length L may extend from a distal end of the fluid pathway <NUM> to a proximal end of the fluid pathway <NUM>. As an example, the length L may extend from a distal end <NUM> of the fluid pathway <NUM> to a proximal end <NUM> of the fluid pathway <NUM>. As another example, the length L may extend from a distal end of a tube <NUM> to a proximal end of the tube <NUM>. In some embodiments, the length L may correspond to a length or an entire length of the adapter <NUM>. In some embodiments, the fluid pathway <NUM> may extend along the entire length of the adapter <NUM> from a distal-most portion of the adapter <NUM> to a proximal-most portion of the adapter <NUM>. In some embodiments, the fluid pathway <NUM> may include an inner diameter D. In some embodiments, the inner diameter D may be constant along the length L.

Fluid flow in the fluid pathway <NUM>, which may be tubular, can be analyzed using Poiseuille's equation: <MAT> where ΔP is a change in pressure gradient across the length of the fluid pathway <NUM>, D and L are the inner diameter and length, respectively, of the fluid pathway <NUM>, µ is the viscosity of a fluid, and <MAT> is the fluid resistance. Since µ is the viscosity of the fluid and not part of the extension tube geometry, a geometric factor Gf is defined such that Rf (the fluid resistance) is <MAT>, where <MAT>.

In some embodiments, the fluid pathway <NUM> may have multiple sections with lengths (L1, L2, L3) and inner diameters of (D1, D2, D3), the geometric factor is then: <MAT> In some embodiments, the fluid pathway <NUM> may have an inner diameter that changes over the length of the fluid pathway <NUM>, the geometric factor is then: <MAT> In some embodiments, the fluid pathway <NUM> may have a cross section that is not circular or may have a complicated inner diameter profile. The geometric factor can then be determined by measuring the flow rate (Q) at given pressure (ΔP) with known viscosity (µ) fluid: <MAT>.

The Gfvalue of the fluid pathway <NUM> may be selected to reduce the maximum shear stress for each catheter gauge to be the same or less than the maximum shear stress of a BD <NUM> VACUTAINER®UltraTouch™ push button blood collection set (available from Becton, Dickinson & Company of Franklin Lakes, New Jersey), which was previously considered the gold standard for blood draws. In some embodiments, Gf may be equal to or more than <NUM>. 83E+<NUM> (<NUM>/in<NUM>) when a <NUM> catheter is used, which may reduce the wall sheer stress to reduce hemolysis. In some embodiments, Gf may be equal to or more than <NUM>. 27E+<NUM> (<NUM>/in<NUM>) when a <NUM> catheter is used, which may reduce the wall sheer stress to reduce hemolysis. In some embodiments, Gf may be equal to or more than <NUM>. 33E+<NUM> (<NUM>/in<NUM>) when a <NUM> catheter is used, which may reduce the wall sheer stress to reduce hemolysis. In some embodiments, Gf may be equal to or more than <NUM>. 50E+<NUM> (<NUM>/in<NUM>) when a <NUM> catheter is used, which may reduce the wall sheer stress to reduce hemolysis. In some embodiments, Gf may include another value. In some embodiments, Gf value of the fluid pathway may be selected to reduce the maximum shear stress for each catheter gauge to be the same or less than the maximum shear stress of a BD <NUM> VACUTAINER® UltraTouch™ push button blood collection set (available from Becton, Dickinson & Company of Franklin Lakes, New Jersey).

In some embodiments, when a <NUM> catheter is used, Gf may be equal to <NUM>. 83E+<NUM> (<NUM>/in<NUM>) plus or minus <NUM> percent, plus or minus <NUM> percent, plus or minus <NUM> percent, or plus or minus <NUM> percent, which may reduce the wall sheer stress to reduce hemolysis. In some embodiments, when a <NUM> catheter is used, Gf may be equal to <NUM>. 27E+<NUM> (<NUM>/in<NUM>) plus or minus <NUM> percent, plus or minus <NUM> percent, plus or minus <NUM> percent, or plus or minus <NUM> percent, which may reduce the wall sheer stress to reduce hemolysis. In some embodiments, when a <NUM> catheter is used, Gf may be equal to <NUM>. 33E+<NUM> (<NUM>/in<NUM>) plus or minus <NUM> percent, plus or minus <NUM> percent, plus or minus <NUM> percent, or plus or minus <NUM> percent, which may reduce the wall sheer stress to reduce hemolysis. In some embodiments, when a <NUM> catheter is used, Gf may be equal to <NUM>. 50E+<NUM> (<NUM>/in<NUM>) plus or minus <NUM> percent, plus or minus <NUM> percent, plus or minus <NUM> percent, or plus or minus <NUM> percent, which may reduce the wall sheer stress to reduce hemolysis. In some embodiments, Gf may include another value, which may be selected based on a gauge of the catheter. In some embodiments, Gf values may be selected to be the same for <NUM> through <NUM> catheters.

In some embodiments, the non-linear portion <NUM> may reduce the risk of hemolysis, while at the same time facilitating a compact adapter <NUM>. In some embodiments, the non-linear portion <NUM> may extend through the tube <NUM>, the groove <NUM> (see, for example, <FIG>) or another suitable structure. In some embodiments, a distal end of the tube <NUM> and/or a proximal end of the tube <NUM> may be secured within the adapter <NUM> at various suitable locations.

In some embodiments, the adapter <NUM> may include a lumen <NUM>, which may extend through the distal end <NUM> of the adapter <NUM> and the proximal end <NUM> of the adapter <NUM>. In some embodiments, the tube <NUM> may be disposed within the lumen <NUM>. In some embodiments, the adapter <NUM> may include a middle portion <NUM> disposed between the distal end <NUM> and the proximal end <NUM>. In some embodiments, the middle portion <NUM> may surround the tube <NUM>. In some embodiments, the adapter <NUM> may house the tube <NUM> with the only openings in the adapter <NUM> being at the distal end <NUM> and the proximal end <NUM>.

Referring now to <FIG>, in some embodiments, the proximal end <NUM> may be coupled to the blood collection device <NUM>. For example, the proximal end <NUM> may be integrated with the blood collection device <NUM> or monolithically formed with the blood collection device <NUM> as a single unit. As another example, the proximal end <NUM> may include the female luer connector, which may be coupled with a male luer connector of the blood collection device <NUM>.

As illustrated in <FIG>, in some embodiments, the blood collection device <NUM> may include a needle assembly <NUM>, which may include a needle <NUM> configured to receive a blood collection container. In these and other embodiments, the blood collection container may include an evacuated blood collection tube. In some embodiments, the blood collection container may have all or a portion of air removed so pressure within the blood collection container is lower than ambient pressure.

In some embodiments, the needle assembly <NUM> may include one or more threads, which may be configured to couple to a holder <NUM>, which may be generally cylindrical and may be configured to hold the blood collection container. In some embodiments, the holder <NUM> may be integrally formed with the needle assembly <NUM> or coupled to the needle assembly <NUM> via bonding or another suitable method. In some embodiments, the holder <NUM> may surround the needle <NUM>. In some embodiments, the needle assembly <NUM> and the holder <NUM> may include or correspond to a luer lock access device, such as, for example, the VACUTAINER® LUER-LOK™ Access Device available from Becton, Dickinson and Company of Franklin Lakes, New Jersey. In some embodiments, a distal end of the needle assembly <NUM> may include the male luer connector compatible with the proximal connector <NUM>.

In some embodiments, a proximal end of the needle <NUM> may be enveloped within an elastomeric sheath <NUM>. In some embodiments, the elastomeric sheath <NUM> may include an open distal end and a closed proximal end. In some embodiments, in response to the blood collection container <NUM> pushing the elastomeric sheath <NUM> distally, the needle <NUM> may pierce the elastomeric sheath <NUM>, and the needle <NUM> may insert into a cavity of the blood collection container.

In some embodiments, the fluid pathway of the vascular access system, which may include one or more of the needle assembly <NUM>, the adapter <NUM>, and the catheter assembly <NUM> (which may include an extension tube), may include an entirety of a blood collection pathway through which blood flows during blood collection. The system geometric factor Gfs for the fluid pathway of the vascular access system can be determined in similar fashion as described earlier. In some embodiments, the system geometric factor Gfs may be equal to or more than <NUM>. 34E+<NUM> (<NUM>/in<NUM>). In some embodiments, Gfs may include another value. In some embodiments, the system geometric factor Gfs may be <NUM>. 34E+<NUM> (<NUM>/in<NUM>) plus or minus <NUM> percent, plus or minus <NUM> percent, plus or minus <NUM> percent, or plus or minus <NUM> percent. In some embodiments, Gfs may include another value, which may be selected based on a gauge and/or length of the catheter. In some embodiments, an inner diameter of the adapter <NUM> may be equal to or greater than a smallest inside diameter of a rest of the complete blood collection pathway for blood collection.

As illustrated in <FIG>, in some embodiments, the blood collection device <NUM> may include a syringe <NUM>, which may include a depressible plunger.

As illustrated in <FIG>, in some embodiments, the blood collection device <NUM> may include the needle assembly <NUM>, which may not include the holder <NUM>.

Referring now to <FIG>, an adapter <NUM> is illustrated, according to some embodiments. In some embodiments, the adapter <NUM> may be similar or identical to the adapter <NUM> of <FIG> in terms of one or more included features and/or operation. In some embodiments, the distal connector <NUM> of the adapter <NUM> may include a blunt cannula <NUM> which may insert into a portion of the catheter assembly and/or one or more arms <NUM> that may clip onto a portion of the catheter assembly.

Referring now to <FIG>, an adapter <NUM> is illustrated, according to some embodiments. In some embodiments, the adapter <NUM> may be similar or identical to the adapter <NUM> of <FIG> and/or the adapter <NUM> of <FIG> in terms of one or more included features and/or operation. In some embodiments, the distal connector <NUM> of the adapter <NUM> may include a male luer slip connector <NUM>.

Referring now to <FIG>, an adapter <NUM> is illustrated, according to some embodiments. In some embodiments, the adapter <NUM> may be similar or identical in terms of one or more included features and/or operation to one or more of the following: the adapter <NUM> of <FIG>, the adapter <NUM> of <FIG>, and the adapter <NUM> of <FIG>. In some embodiments, the non-linear portion <NUM> may form an S-shape <NUM> or another suitable shape.

Referring now to <FIG>, an adapter <NUM> is illustrated, according to some embodiments. In some embodiments, the adapter <NUM> may be similar or identical in terms of one or more included features and/or operation to one or more of the following: the adapter <NUM> of <FIG>, the adapter <NUM> of <FIG>, the adapter <NUM> of <FIG>, and the adapter <NUM> of <FIG>. For example, the adapter <NUM> may be coupled to the blood collection device <NUM> (see, for example, <FIG>).

In some embodiments, the non-linear portion <NUM> of the fluid pathway <NUM> may include a channel or a groove <NUM>. In some embodiments, the groove <NUM> may be disposed in an outer surface of an inner component <NUM>, which may be coupled to an outer component <NUM>. In some embodiments, the groove <NUM> may include a coil or spiral shape. In some embodiments, the groove <NUM> may be proximate an inner surface of the outer component <NUM>, which may close the groove <NUM> such that fluid flowing through the groove <NUM> may not escape the groove <NUM> except at a distal end and a proximal end of the groove <NUM>.

In some embodiments, contact between the inner component <NUM> and the outer component <NUM> may form a seal between the inner component <NUM> and the outer component <NUM>. In some embodiments, the outer surface of the inner component <NUM> may include a seal element <NUM>, which may include silicon, rubber, plastic, or another suitable material. In some embodiments, the seal element <NUM> may include a coil or spiral shape and may be offset from the groove <NUM> in the distal-proximal direction. In some embodiments, the seal element <NUM> may prevent fluid from escaping the groove <NUM> except at a distal end and a proximal end of the groove <NUM>.

In some embodiments, an outer diameter of the inner component <NUM> may be approximately equal to or slightly less than an inner diameter of the outer component <NUM> such that the inner component <NUM> is fitted within the outer component <NUM>. In some embodiments, the inner surface of the outer component <NUM> may be generally cylindrical, and the outer surface of the inner component <NUM> may be generally cylindrical. In some embodiments, the inner component <NUM> and the outer component <NUM> may be concentric. In some embodiments, the inner component <NUM> and the outer component <NUM> may be integrally formed or monolithically formed as a single unit.

In some embodiments, the outer component <NUM> may include the distal end <NUM>, which may include the distal connector <NUM> of <FIG>, <FIG>, or <FIG> or another suitable connector. In some embodiments, the inner component <NUM> may include the proximal end <NUM>, which may include the proximal connector <NUM> such as a female luer connector or another suitable connector.

In some embodiments, a proximal end of the groove <NUM> may include a hole <NUM> that may fluidically connect the groove <NUM> to an opening <NUM> of the proximal end <NUM>. Similarly, in some embodiments, a distal end of the groove <NUM> may include a hole that may fluidically connect the groove <NUM> to an opening <NUM> of the distal end <NUM>.

Claim 1:
An adapter (<NUM>), comprising:
a distal end (<NUM>), comprising a distal connector (<NUM>) configured to couple to a catheter assembly (<NUM>);
a proximal end (<NUM>), comprising a proximal connector (<NUM>) configured to couple to a blood collection device (<NUM>); and
a fluid pathway (<NUM>) disposed between the distal end (<NUM>) and the proximal end (<NUM>),
characterized in that the fluid pathway (<NUM>) includes a non-linear portion (<NUM>) configured such that no fluid flowing through the non-linear portion (<NUM>) may flow in a straight line, with the non-linear portion (<NUM>) increasing a length of the fluid pathway (<NUM>) between the distal end (<NUM>) and the proximal end (<NUM>) as compared to a linear fluid pathway.