Patent ID: 12201800

DETAILED DESCRIPTION

As used herein, the terms “proximal” and “distal” may refer to the direction closer to and away from, respectively, a clinician who would place the catheter system into contact with a patient. Thus, for example, the end of the catheter system first touching the body of the patient would be the distal end, while the opposite end of the catheter system would be the proximal end of the catheter system.

An extension set in accordance with some embodiments may provide access to a patient's vascular system. As discussed in more detail below, in some embodiments, the extension set may provide access to a fluid pathway of a catheter assembly. In some embodiments, the extension set may provide access to the vasculature of a patient throughout a dwell time of the catheter assembly for infusion, blood draw, or delivering a sensor for measurement.

As previously mentioned, a catheter with significant dwell time within the vasculature of the patient may be susceptible to narrowing, collapse, kinking, blockage by debris (e.g., fibrin, platelet clots, or thrombus), and adhering of a tip of the catheter to vasculature of a patient. Thus, blood withdrawal using the catheter may be difficult. Advantageously, in some embodiments, the extension set may include an instrument, such as another catheter or a probe, disposed within a tube. In some embodiments, the instrument may provide access to the vasculature of the patient without any additional needle sticks. Thus, in some embodiments, the extension set100may be used for needle-free blood collection and/or fluid infusion.

Referring now toFIG.1, in some embodiments, the extension set100may include the tube102, which may include a proximal end104, a distal end106, and an outer surface108. In some embodiments, the tube102may be flexible, rigid, or semi-rigid. In some embodiments, the instrument110may be disposed within the tube102and may include a proximal end112and a distal end114. The distal end114may be atraumatic or blunt in some embodiments. In some embodiments, the extension set100may provide a non-fluid path through the tube102to shield the instrument110from contaminants and the surrounding external environment. The non-fluid path may be configured such that blood withdrawn from the patient does not contact the non-fluid path. In some embodiments, the extension set100may also isolate blood or other fluids that may remain on the instrument110after use. Further, in some embodiments, the extension set100may provide support, alignment, and aseptic delivery of the instrument110through the catheter assembly and into the patient's vascular system.

In some embodiments, a translation handle116may be coupled to the outer surface108of the tube102to facilitate moving the instrument110without requiring direct contact with the instrument110. In some embodiments, the translation handle116may move along a length of the outer surface108of the tube102between a proximal position and a distal position. In some embodiments, the tube102may include an axially-compressible, bio-compatible, and an elastomeric or polymeric material. In this manner, in some embodiments, the translation handle116may create localized compression of the tube102.

As discussed in more detail below, in some embodiments, a compressed portion of the tube102may engage with a coupler element117coupled to the proximal end112of the instrument110such that the translation handle116may translate the distal end114of the instrument110in the direction of movement of the translation handle116. In some embodiments, the translation handle116may translate the distal end114of the instrument110between a retracted position and an advanced position. In the advanced position124, as illustrated inFIG.1, the distal end114of the instrument110may extend beyond the distal end106of the tube102and into a catheter assembly and/or vasculature of a patient, for example.

Referring now toFIG.2, in some embodiments, the extension set100may be coupled to a catheter assembly200, which may include a distal end204. In some embodiments, the instrument110may extend through the distal end204of the catheter assembly200in response to the translation handle116moving to the distal position. In some embodiments, the extension set100may be permanently coupled to, integrated with, or monolithically formed as a single unit with the catheter assembly200.

In some embodiments, the instrument110may include a probe having one or more openings and/or sensors to provide in-vein patient and device monitoring. In some embodiments, the probe openings and/or the sensors may be disposed towards the distal end114. In some embodiments, the openings may serve as fluid inlets and/or outlets. In some embodiments, the sensors may measure one or more parameters and/or detect one or more elements related to, for example, diagnostic information, blood chemistry, pH, temperature, pressure, flow rate, drug identification, microbes, placement of an implantable stent, in-vein catheter tip stabilization feature, or other devices or physiological measures. In some embodiments, the extension set100may facilitate placement of a portion of the probe that includes the sensors within the fluid pathway of the catheter assembly and/or the vasculature of the patient.

In some embodiments, the instrument110may include tubing and may function as both a probe and a catheter, including elements of both. In some embodiments, the instrument110may include the tubing to provide fluid infusion and/or withdrawal. In some embodiments, the tubing may include a standard catheter tip or an asymmetrical catheter tip. In some embodiments, diffuser holes may be disposed in a tip of the tubing. In some embodiments, the tubing may include polyurethane, FEP, Teflon, silicon, TPE, TPU, fluorinated polymers, polyimide, or any other suitable materials or combination thereof. In some embodiments, the tubing material may be hydrophilic, hydrophobic, and/or may include any other desired properties or features, such as an anti-fouling material. Some embodiments of the tubing may include a coating such as an anti-thrombogenic and/or antimicrobial coating or other coating to impart other desired properties to the tubing.

In some embodiments, an extension tube206may be coupled to a proximal end of the translation handle116and/or the proximal end112of the instrument110. In some embodiments, the extension tube206may be flexible. In some embodiments, the extension tube206may include TPE, TPU, PVC, or other suitable medical tubing material. In some embodiments, the extension tube206may be substantially clear and/or may include markers to inform a clinician of the position of the instrument110relative to the catheter or catheter features. In some embodiments, the extension tube206may include a textured surface to reduce contact friction. Some embodiments of the extension tube206may be vented by, for example, an open air pathway, a breathable filter membrane, porous venting material, micro-channels, or the like.

In some embodiments, a proximal connector208may be coupled to or integrated with the proximal end of the extension tube206to connect to a blood collection device210(see, for example,FIG.3), infusion device, or monitoring device, for example. In some embodiments, the blood collection device may include any suitable blood collection device, such as, for example, a VACUTAINER® or a VACUTAINER® LUER-LOK™ Access Device (LLAD), available from Becton Dickinson and Company of Franklin Lakes, N.J. The proximal connector208may include, for example, a male or female luer, a blunt cannula, or another suitable connector. In some embodiments, the blood collection device210may be selectively coupled to the proximal connector208. In some embodiments, the blood collection device210may be pre-connected to the proximal connector208during manufacture or assembly. In some embodiments, the blood collection device210may be permanently coupled to, integrated with, or monolithically formed as a single unit with the proximal connector208.

In some embodiments, the distal end106of the tube102may be coupled to or integrated with the distal connector212, which may include a fluid seal214to seal the tube102and create a closed fluid path. In some embodiments, the distal connector212may include, for example, a male or female luer, a blunt cannula, or another suitable connector. In some embodiments, the distal connector212may include lever arms and/or clips to aid with securement.

In some embodiments, the extension tube206may extend through a proximal connector209integrated with or coupled to the proximal end104of the tube102. In some embodiments, there may be a tight fit or septum between the extension tube206and the proximal connector209, which may create a seal but still allow motion of the extension tube206with respect to the proximal connector209. In some embodiments, the translation handle116may be moved from the proximal position to the distal position such that the distal end114of the instrument110is distally advanced beyond the tube102and/or the proximal connector208is moved closer to the proximal connector209. In some embodiments, after blood has been collected in the blood collection device210, the translation handle116may be moved from the distal position to the proximal position such that the distal end114of the instrument110retracts into the tube102and/or the proximal connector208is moved away from the proximal connector209. In some embodiments, the translation handle116may include any suitable translation handle, which may be described, for example, in further detail in U.S. patent application Ser. No. 17/127,588, filed Dec. 17, 2020, entitled “FLUSH INSTRUMENT WITH BLOOD EXPOSURE PROTECTION AND RELATED METHODS” and U.S. patent application Ser. No. 17/127,623, filed Dec. 17, 2020, entitled “MULTI-LUMEN EXTENSION SYSTEM,” which are incorporated by reference in their entirety.

In some embodiments, the extension set100may reduce hemolysis of a blood sample collected via the fluid path. In some embodiments, the extension set100may provide an adequate fluid flow rate. Blood cell experiences shear stress as it flows in a fluid pathway. 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. For a cylindrical fluid path, the wall shear stress is typically expressed as:

T=12·Δ⁢pL·(kr)
in which ΔP is the pressure drop along a path with a length of L and an interior radius of r. k is shrinkage index.

To fill a certain volume of collection tube, V, with a flow rate of Q, the time needed can be simply assessed by:

t=vℚ=8⁢μv·1π⁢r4/(Δ⁢pL)
in which μ is the dynamic viscosity of the fluid. Hemolysis is typically associated with both the wall shear stress and the time a blood cell is exposed to wall shear stress. From literature, it has been widely considered that hemolysis index can be approached as a function of:
HI(%)=A*tα*Tβ
in which A, α, and β are coefficients.

In principle, the hemolysis index is related to pressure gradient and cross-sectional characteristic dimension:

HI⁡(%)∝(Δ⁢Pl)β-α·(1r)4⁢α-β

In some embodiments, a length of the instrument110may be selected based on one or more of the following: a gauge of a particular catheter, a particular catheter assembly configuration, or a clinical setup. In some embodiments, the instrument110may include a length L. In some embodiments, the instrument110may include an inner diameter D.

Fluid flow in instrument110can be analyzed using Poiseuille's equation when the instrument110is tubular:

Q=π⁢D4⁢Δ⁢P1⁢2⁢8⁢μ⁢L=Δ⁢PRf
where ΔP is a change in pressure gradient across the length of a fluid pathway of the instrument110, D and L are the inner diameter and length, respectively, of the fluid pathway of the instrument110, μ is the viscosity of a fluid, and

Rf=1⁢2⁢8⁢μ⁢Lπ⁢D4
is the fluid resistance. Since μ is the viscosity of the fluid and not part of the extension tube geometry, a geometric factor Gfis defined such that Rf(the fluid resistance) is

Rf=1⁢2⁢8⁢μπ⁢Gf,
where

Gf=LD4.

In some embodiments, the instrument110may have multiple sections with lengths (L1, L2, L3) and inner diameters of (D1, D2, D3), the geometric factor is then:

Gf=L⁢1D⁢14+L⁢2D⁢24+L⁢3D⁢34
In some embodiments, the instrument110may have an inner diameter that changes over the length of the instrument110, the geometric factor is then:

Gf=∫0Ld⁢lD⁡(l)4
In some embodiments, the instrument110may have a cross section that is not circular or complicated inner diameter profile. The geometric factor can be determined by measuring the flow rate (Q) at given pressure (ΔP) with known viscosity (μ) fluid:

Gf=π⁢Δ⁢P1⁢2⁢8⁢μ⁢Q

The Gfvalue of the instrument110may be selected to reduce the max shear stress for each catheter gauge to be the same or less than the max shear stress of a BD 21G VACUTAINER® UltraTouch™ push button blood collection set (available from Becton, Dickinson & Company of Franklin Lakes, N.J.), which was previously considered the gold standard for blood draws. In some embodiments, Gfvalue of the fluid pathway of the instrument110may be selected to reduce the max shear stress for each catheter gauge to be the same or less than the max shear stress of a BD 25G VACUTAINER® UltraTouch™ push button blood collection set (available from Becton, Dickinson & Company of Franklin Lakes, New Jersey).

In some embodiments, a fluid pathway of a blood collection system, which may include one or more of the blood collection device210, the tube102, the instrument110, and the catheter assembly200, may include an entirety of a blood collection pathway through which blood flows during blood collection after leaving vasculature of a patient. The system geometric factor Gfsfor the fluid pathway of the blood collection system can be determined in similar fashion as described earlier. In some embodiments, the system geometric factor Gfsmay be equal to or more than 7.34E+06 (1/in3). In some embodiments, Gfsmay include another value. In some embodiments, the system geometric factor Gfsmay be equal to or more than 7.34E+06 (1/in3) when the instrument110is in an advanced position. In some embodiments, the system geometric factor Gfsmay be 7.34E+06 (1/in3) plus or minus 10 percent, plus or minus 25 percent, plus or minus 50 percent, or plus or minus 75 percent. In some embodiments, Gfsmay include another value, which may be selected based on a gauge and/or length of the catheter.

In some embodiments, the distal connector212may couple the extension set100to the catheter assembly200. In some embodiments, the catheter assembly200may include a catheter adapter220, which may include a distal end221, a proximal end222, and a lumen extending there through. In some embodiments, the catheter adapter220may include a side port224, from which another extension tube may extend. In some embodiments, the other extension tube may be coupled to an adapter, such as a Y-adapter or a T-adapter, for example. In some embodiments, the distal end106of the tube102may be coupled to the proximal end222of the catheter adapter220, the side port224, the adapter, or another portion of the catheter assembly200. In some embodiments, the distal end204of the catheter assembly200may include a catheter223, which may be secured within the catheter adapter220and extend distally from the distal end221of the catheter adapter220. In some embodiments, the catheter223may include a peripheral IV catheter, a midline catheter, or a peripherally-inserted central catheter.

In some embodiments, the catheter223may include a standard catheter tip or an asymmetrical catheter tip. In some embodiments, the catheter223may include one or more diffuser holes may be disposed in a tip of the catheter223. In some embodiments, the catheter223may include polyurethane, FEP, Teflon, silicon, TPE, TPU, fluorinated polymers, polyimide, or any other suitable materials or combination thereof. In some embodiments, the catheter223material may be hydrophilic, hydrophobic, and/or may include any other desired properties or features, such as an anti-fouling material. Some embodiments of the catheter223may include a coating such as an anti-thrombogenic and/or anti-microbial coating or other coating to impart other desired properties to the catheter223.

In some embodiments, the extension set100may provide needle free delivery of the instrument110to a patient's vascular system for blood collection, fluid delivery, patient or device monitoring, or other clinical needs by utilizing an existing vascular access device (VAD), such as the catheter223. In some embodiments, the extension set100and the instrument110may reduce trauma to the vein and overcome thrombus and fibrin sheath in or around the VAD or vein that may otherwise prevent infusion or blood draw. In some embodiments, the instrument110may push past any obstructions in the VAD or the vein in order to open a pathway for vascular access. In some embodiments, a suction device such as a LLAD or syringe may be attached to the proximal end of the extension set100in order to complete a blood draw. After completing a blood draw or infusion the user may retract the instrument110by rolling the translation handle116proximally. This allows the clinician to disconnect the extension set100from the VAD without exposing themselves to blood.

Referring now toFIGS.3-4, in some embodiments, the fluid seal214may permit advancement and/or retraction of the instrument110there through while maintaining a closed fluid path. In some embodiments, the fluid seal214may include silicone rubber, an elastomer, or another suitable material. In some embodiments, the fluid seal214may include an aperture, slit, or the like to accommodate the instrument110there through.

In some embodiments, the compressed portion302of the tube102may engage with the coupler element117such that movement of the translation handle116along the outer surface108of the tube102translates the distal end114of the instrument110between the retracted position, illustrated inFIG.3, and the advanced position, illustrated inFIG.4. In some embodiments, the coupler element117may be coupled to the instrument110and/or the extension tube206by, for example, an interference fit, adhesive, or both. In some embodiments, the extension tube206and the instrument110may be monolithically formed as a single unit and may extend through the coupler element117.

Referring now toFIGS.5A and5B, in some embodiments, the coupler element117may engage or otherwise engage with one or more features of the translation handle116through the tube102to allow translation of the instrument110without any direct contact between the translation handle116and the coupler element117that is coupled to the instrument110. For example, in some embodiments, as illustrated inFIG.5A, the coupler element117may include a disc or ellipsoid shape506with a flattened or concave center portion504. The flattened or concave center portion504may align with opposing features500of the translation handle116to facilitate smooth translation. In some embodiments, the features500may include rollers, ball bearings, low-friction sliding surfaces, or the like. In some embodiments, the features500may be rounded, angled, spherical, or cylindrical. In some embodiments, the features500may include at least one of the following: a first feature500a, a second feature500b, a third feature500c, a fourth feature500d, or any combination thereof.

In some embodiments, a distance between features500that oppose each other may be less than an outer diameter of the tube102such that the tube102is pinched between the features500and the coupler element117. In some embodiments, as illustrated inFIG.5B, the coupler element117may include a disc or ellipsoid shape having tapered ends508. The tapered ends508may accommodate the features500of the translation handle116to facilitate smooth translation. The tapered ends508may include a distal tapered end508aand a proximal tapered end508b.

In some embodiments, the features500may be coupled to the translation handle116to provide localized compression of the tube102. In some embodiments, the features500may engage with the coupler element117via the tube102to facilitate smooth translation of the instrument110within the tube102. In some embodiments, the features500may be coupled to an interior edge of the translation handle116. In some embodiments, the surface of the coupler element117that interfaces with the features500may be substantially concave to facilitate smooth bi-lateral movement along the outer surface108of the tube102.

According to various embodiments, the coupler element117may include the tapered ends508to improve its ability to round corners during movement between the proximal end104and the distal end106of the tube102. In these and other embodiments, the coupler element117may include fins to facilitate travel down the tube102. In some embodiments, the coupler element117may include fenestrations, ribs, or channels to facilitate fluid flow, such as air and/or liquid. In some embodiments, air may flow around the coupler element117such as through the fenestrations, ribs, or channels, so a vacuum is reduced or eliminated in response to moving the coupler element117distally or proximally. In other embodiments, the coupler element117may include a bore to accommodate fluid flow, such as fluid infused into the patient's vascular system, for example, or blood aspirated from the patient's vascular system. In some embodiments, the coupler element117may include one or more colors or patterns to increase its visibility.

In some embodiments, longitudinal ribs may be molded onto an outer surface of the coupler element117to keep the coupler element117oriented parallel to the tube102, thus facilitating unobstructed bi-directional movement of the coupler element117through the tube102. In some embodiments, the longitudinal ribs may contact opposing features on an inner surface of the tube102to prevent the coupler element117from rotating within the tube102.

In some embodiments, the coupler element117and/or an inner surface of the tube102may include a lubricant304to facilitate translation of the instrument110within the tube102. In some embodiments, the lubricant304may be disposed around the coupler element117and/or inside a non-fluid path lumen510of the tube102. In other embodiments, the lubricant304may be applied external to the non-fluid path lumen510around the features500of the translation handle116. In some embodiments, the coupler element117may include lubricious material to facilitate movement within the non-fluid path lumen510. In these and other embodiments, the extension set100may include venting to maintain atmospheric pressure and allow movement of air within the non-fluid path lumen510during bi-directional translation of the instrument110. In some embodiments, the non-fluid path lumen510may include venting to allow airflow into and out of the non-fluid path lumen510, which may facilitate movement of the translation handle116and coupler element117. In some embodiments, one or more vents to provide the venting may be reduced in size to allow air movement while still maintaining good aseptic protection of the instrument110and/or other portions of the extension set100.

Referring now toFIGS.6-8, in some embodiments, the extension set100and the catheter assembly200may include a fluid path assembly600that facilitates blood collection. In some embodiments, the fluid path assembly600may include the instrument110, which may include the tubing, such as, for example, micro-tubing. In some embodiments, tubing may include a polymer material, polyimide, or another suitable material. In some embodiments, the proximal connector208may be coupled to a needle-less connector or a female luer connector. In some embodiments, blood may flow through the instrument110and through the extension tube206into the blood collection device.

In some embodiments, a non-fluid path extension assembly602may provide support, alignment, and aseptic delivery of the instrument110through a catheter (see, for example, the catheter223ofFIG.2) dwelling within the vasculature. In some embodiments, a majority of the non-fluid path extension assembly602or a portion of the non-fluid path extension assembly602proximal to the fluid seal214may not contact blood being withdrawn from the patient through the extension set100. In some embodiments, a portion of the non-fluid path extension assembly distal to the fluid seal214may have some contact with blood or saline solution that may be in a fluid path of the catheter. In some embodiments, the non-fluid path extension assembly602may include one or more of: the tube102, the translation handle116, the distal connector212at the distal end106, and the proximal connector209disposed at the proximal end. In some embodiments, the distal end106of the tube102and/or the distal connector212may include the fluid seal214to seal the distal end of the non-fluid path extension assembly602. In some embodiments, the fluid seal214may form a seal around the instrument110, which may extend there through. Advantageously, the extension set100in accordance with some embodiments may be easy to scale in length, based on, for example, a size or length of the catheter123or the catheter assembly200.

Referring now toFIGS.9A and9B, in some embodiments, the translation handle116may include a collar900around the tube102. The tube102is illustrated as transparent inFIG.9Bfor illustrative purposes. In some embodiments, the collar900may extend fully or partially around the tube102. In some embodiments, the collar900may move bi-directionally along the tube102. In some embodiments, the collar900and the coupler element117may be magnetically attracted to each other through the tube102to facilitate movement of the instrument110without direct contact. These and other embodiments of the collar900may include the features500to improve ease of movement along the outer surface108of the tube102. In some embodiments, an outer surface of the collar900may include one or more grips, such as, for example, ribs, textured surfaces, push tabs, or other protrusions to provide ease of handling.

In some embodiments, the features500may include one, two, or three ball bearings distributed radially symmetrically about the longitudinal axis of the tube102. In some embodiments, the features500may be coupled to an inside surface of the collar900to mediate contact between the collar900and the outer surface108of the tube102. In other embodiments, any number of the features500may be present and may be arranged in a variety of symmetrical and asymmetrical arrangements.

Referring now toFIGS.10A-11C, the translation handle116may include a housing1000, which may include a distal opening1002and a proximal opening1004. In some embodiments, the tube102may extend through the distal opening1002and the proximal opening1004. In some embodiments, the housing1000may extend around the tube102. In some embodiments, the housing1000may move bi-directionally along the tube102. In some embodiments, the housing1000and the coupler element117may be magnetically attracted to each other through the tube102to facilitate movement of the instrument110without direct contact of the instrument110by the clinician.

In some embodiments, the translation handle116may compress a portion of the tube102in between the coupler element117and the translation handle116. In some embodiments, the portion of the tube102may engage the coupler element117such that movement of the translation handle116along the outer surface108of the tube102translates the coupler element117within the tube102and the distal end114of the instrument110is moved between the retracted position and the advanced position.

In some embodiments, the housing1000may include the features500to improve movement of the translation handle116along the outer surface108of the tube102. In some embodiments, the features500may be coupled to an inside surface of the housing1000to mediate contact between the housing1000and the outer surface108of the tube102. In some embodiments, any number of the features500may be present and may be arranged in a variety of symmetrical and asymmetrical arrangements.

In some embodiments, the features500which may include ball bearings, wheels, low-friction sliders, or other suitable features to provide localized compression of the tube102to engage the coupler element117. In some embodiments, the features500may be coupled to the translation handle116. In some embodiments, the features500may be directly coupled to the translation handle116. In some embodiments, the features500and the translation handle116may be molded together or monolithically formed as a single unit. In some embodiments, the features500and the translation handle116may be integrated or fitted together.

In some embodiments, the features500may include a pinch mechanism and may be positioned to pinch or press against the outer surface108of the tube102. In some embodiments, one or more of the features500may oppose or be on opposite sides of the tube102as one or more other of the features500. In some embodiments, an interior surface of the tube102within the translation handle116may be too small to permit passage of the coupler element117there through. In some embodiments, the housing1000may be rigid or semi-rigid, which may provide more support to the clinician for one-handed advancement of the instrument110by the clinician.

As illustrated, for example, inFIGS.11A-11B, the features500may include wheels1100, which may be rotatably coupled to the translation handle116. In some embodiments, an axle1102may extend through the features500. In some embodiments, the features500may include sliders, which may be slick and/or constructed of plastic, and which may slide along the tube102. In some embodiments, the sliders may be stationary or static with respect to the translation handle116.

As illustrated, for example inFIG.11C, the features500may include the ball bearings, which may be rotatable within sockets formed in the translation handle116. In some embodiments, the features500may include at least one of the following: a first feature500a, a second feature500b, a third feature500c, a fourth feature500d, or any combination thereof. In some embodiments, each of the sockets may include ridges or bumps around a circumference of the socket, which may limit contact of the ball bearings with the socket and reduce friction. In some embodiments, the ball bearings may have the ridges or bumps, which may be disposed between the ball bearing and the housing1000. In some embodiments, the bumps may be evenly spaced around the circumference. In some embodiments, lubricant may be applied to the coupler element117and/or the features to reduce friction.

In some embodiments, an outer surface of the housing1000may include one or more grips1006, such as, for example, ribs, textured surfaces, push tabs, protrusions, or indents to provide ease of handling. In some embodiments, the grips1006may be disposed on sides of the housing1000, as illustrated, for example, inFIGS.10A-10D. In some embodiments, the grips1006may be disposed on sides and/or the top of the housing1000, as illustrated, for example, inFIG.10C. In some embodiments, the housing1000may include various shapes, such as, for example, rectangular, square, cylindrical, elliptical, or another suitable shape. In some embodiments, a middle portion of the housing1000may include a diameter that is less than a diameter of a first end of the housing1000and/or a diameter of the second end of the housing1000opposite the first end. In these and other embodiments, the shape of the housing1000may facilitate gripping of the housing1000by the clinician.

In some embodiments, the coupler element117may include fenestrations, ribs, or channels to facilitate fluid flow, such as air and/or liquid. Thus, in some embodiments, the tube102may be in fluid communication with the proximal connector209. In some embodiments, the proximal connector209may be coupled to a needleless connector1104, which may include a septum. In some embodiments, the blood collection device may be coupled to the needleless connector1104, and blood may be withdrawn proximally through one or more of the following: the tube102, the coupler element117, the proximal connector209, and the needleless connector1104. In some embodiments, the needleless connector1104may be coupled to the proximal connector209via a luer adapter. In some embodiments, the needleless connector1104may be permanently connected to the proximal connector209, which may include the luer adapter, with adhesive or another suitable means to prevent intentional or unintentional removal by the clinician.

Referring now toFIGS.12A-12F, the coupler element117may include various shapes. In some embodiments, the coupler element117may include a distal end1200, from which the instrument110may extend, and a proximal end1202. As illustrated, for example, inFIG.12A, the coupler element117may include a cylinder or barrel shape. As illustrated, for example, inFIGS.12B-12D, the coupler element117may include a tapered exterior. As illustrated, for example, inFIGS.12C-12D, the coupler element117one or more rounded ridges to improve ability to round corners. In some embodiments, the coupler element117may include fins to help the coupler element117travel down the tube102. In some embodiments, the coupler element117may include fenestrations in it to allow fluid to flow around it. In some embodiments, a flow path around the coupler element117may be selected such that a hydraulic diameter is greater than an inner diameter of the blood collection device or tube102to reduce shear stress during blood draw.

As illustrated, for example, inFIG.12F, the coupler element117may include a dog bone or bow shape so that it can be used with two pinch points, two ball bearings, or two wheels, as opposed to four. In some embodiments, the coupler element117may be attached to the instrument110by an interference fit, adhesive, or both. In some embodiments, the instrument110may be tapered so that a large outer diameter end of the instrument110serves as the coupler element117or wedge. In some embodiments, the coupler element117may be colored to increase visibility.

Referring now toFIG.13A, in some embodiments, the blood collection device may be coupled to the proximal connector209and/or a needleless connector coupled to the proximal connector209. In some embodiments, the instrument110may include a tube, and a channel1300may extend through the coupler element117. In some embodiments, the tube may create a closed path for blood flow and prevent contamination of the blood due to drug adsorption in the VAD. In some embodiments, the instrument110may be colored to increase visibility.

In some embodiments, such asFIGS.13A-13B, a fluid pathway may be disposed between an outer surface of the instrument110and an inner surface of the tube102and may extend through the distal connector212and the proximal connector209. Thus, in some embodiments, the distal end106may not include the fluid seal214. In some embodiments, blood may flow proximally through the instrument110and/or the fluid pathway between the outer surface of the instrument110and the inner surface of the tube102. In some embodiments, the blood in the fluid pathway may flow into the blood collection device coupled to the proximal connector209. In some embodiments, the blood collection device may be coupled directly to the proximal connector209or coupled to the proximal connector209via a needleless connector or another suitable device. In some embodiments, during infusion, fluid may flow distally through the fluid pathway between the outer surface of the instrument110and the inner surface of the tube102, and through the distal connector212.

In some embodiments, in some embodiments, the extension set may be coupled to various portions of a particular catheter assembly, and the instrument110may gain access to the vasculature of the patient via various routes. As an example, the instrument110may be advanced through the adapter, such as the Y-adapter or the T-adapter, and/or the other extension tube. In some embodiments, the instrument110may be advanced through a particular side port of a catheter adapter. In some embodiments, a route of the instrument110may be straight and aligned with a longitudinal axis of the particular catheter assembly. In some embodiments, blood may flow into the blood collection device via various routes, such as via one or more of the adapter, the other extension tube, and the side port.

In some embodiments, in order for fluid to flow through the fluid pathway between the outer surface of the instrument110and the inner surface of the tube102, the fluid may flow around and/or through the coupler element117. In some embodiments, one or more fenestrations, ribs, or other channels may facilitate fluid flow from a distal side of the coupler element117to a proximal side of the coupler element117.

Referring now toFIG.13B, in some embodiments, the instrument110may include a guidewire and/or spring, which may be constructed of metal or another suitable material. In some embodiments, the spring may have a varying pitch along its length. For example, the pitch of the spring distal to the tip of the catheter may allow more blood flow and increase flow rate. In some embodiments, the spring may have a smaller pitch near the tip of the catheter to prevent blood clots from entering the VAD, but still allow blood flow through it. In some embodiments, the spring may include the guidewire through the center or along one or more sides of the spring for added stiffness to ease insertion.

Referring now toFIGS.14A-14C, in some embodiments, the distal connector212may include a blunt cannula1400, which may form a distal opening1402. In some embodiments, a cap1406may surround the blunt cannula1400. In some embodiments, the cap1406may include one or more protrusions1408, which may facilitate gripping of the cap1406by the clinician prior to removal of the cap1406from the blunt cannula1400by the clinician. As illustrated, for example, inFIGS.14B-14C, a distal end1410of the cap1406may be closed. As illustrated, for example, inFIG.14C, the cap1406may be adjacent or proximate a proximal end of the blunt cannula1400, which may prevent the instrument110from moving distal to the blunt cannula1400during shipping and/or priming. In some embodiments, the cap1406may include one or more vent holes extending through the cap1406proximal to the distal end1410.

All examples and conditional language recited herein are intended for pedagogical objects to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Although embodiments of the present disclosure have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the disclosed embodiments.