Needle Assembly and Associated Methods

Abstract

A needle assembly (1400), such as a catheter assembly, has a needle shaft portion (12) with a needle tip (14) formed from a first rigid material for puncturing a subject. The shaft (12) proximal to the needle tip (14) can be formed from a second material different from the first material. The needle tip (14) is attached to the needle shaft (12) to form a needle (10). The first material can have a higher rigidity than the second material, and the needle (10) can protrude through a catheter tube (18) and be used in a catheter assembly.

Description

[Technical Field]

[0001] The present invention relates to needles and catheter assemblies including such needles and related methods. [Background technology]

[0002] Cannulation is often a difficult task for both the medical professional and the subject, and requires some skill and experience on the part of the medical professional to manage the process with as little pain or discomfort as possible to the subject.

[0003] Some cannulation systems include a method for the medical practitioner to visualize primary flashback during the cannulation process. For example, some systems include a notched needle that is surrounded by the catheter during insertion. The notch allows blood to enter the annular space between the needle and the catheter tube, allowing the medical practitioner to observe when primary flashback occurs to understand when the needle bevel has entered the vein.

[0004] Incorporating a notch into a metal needle requires additional processing steps in addition to forming the needle into a closed cylindrical body. The additional processing steps complicate the process, increasing time and manufacturing costs. Additionally, blood may escape through the notch, potentially leading to blood exposure upon needle withdrawal.

[0005] Metal also has a low penetration force when compared to needles formed from other materials, making it a preferred material for conventional cannulation systems. A low penetration force allows the needle to more easily enter a patient's vascular system, thus puncturing the vascular system with minimal patient discomfort.

[0006] In general, it would be desirable to overcome or ameliorate one or more of the above-mentioned difficulties, or at least to provide a useful alternative. Summary of the Invention

[0007] The present invention provides a needle comprising: a sharp needle tip formed from a first rigid material for puncturing a subject; and a needle shaft comprising a second material, the needle tip being attached to the needle shaft in use to form the needle.

[0008] The present invention provides a catheter assembly including a needle as described above; a catheter hub; and a catheter connected to the catheter hub and surrounding the needle.

[0009] Embodiments of the present invention further include a needle tip formed from a first rigid material, the needle tip including a bevel for puncturing a target; and a needle shaft comprising a second material, the needle tip being formed separately from and subsequently attached to the needle shaft to form the needle.

[0010] The first material can have a higher stiffness than the second material.

[0011] The first material may be a metal.

[0012] The inner material with the needle tip can be a substrate onto which a second material is attached, molded, or deposited.

[0013] In one example, the substrate can be formed from a non-metallic material and a harder metallic material can be deposited on the substrate.

[0014] In some examples, the substrate can have both a stem portion and a tip portion having a needle bevel. The stem portion can be attached to the tip portion via a coupling.

[0015] The second material may be a plastic material.

[0016] The second material can be optically transparent to allow visual detection of primary flashback within the needle shaft. Primary flashback can be seen through the needle formed using the second material. When used with a catheter, blood can flow into the annular space between the catheter tube and the needle, blocking the needle from view. Flow within the annular space can result in secondary flashback.

[0017] The second material can be transparent or translucent.

[0018] The tip of the needle can be attached to the needle shaft via a coupling. The coupling can have a first coupling portion formed with the needle tip and a second coupling portion formed with the shaft portion. The first coupling portion can be mated with the second coupling portion to form a completed or assembled coupling for attaching the needle tip to the needle shaft.

[0019] The coupling may include one or more recesses in one of the needle shaft and the needle tip, and for each recess, a protrusion in the other of the needle shaft and the needle tip that is positioned to be received in the recess, thereby coupling the needle tip to the needle shaft.

[0020] The coupling includes one or more openings in one of the needle shaft and the needle tip, and for each opening, a protrusion in the other of the needle shaft and the needle tip that is positioned to be received in the opening, thereby enabling the needle tip to be coupled to the needle shaft.

[0021] The needle tip includes a first material having a bevel and either a second material formed on the first material, thereby forming the needle shaft, or the needle shaft is formed from the second material and then connected to the first material.

[0022] The needle shaft may include an integral needle tip at the distal end of the needle shaft, and the needle tip may be attached to the needle shaft by depositing a first material onto the integral needle tip foam.

[0023] The needle tip may include a proximal end including one of a depression and a protrusion, and forming the second material on the needle tip may include depositing the second material from a distal location of the depression or protrusion to and past the proximal end of the needle tip along the length of the needle tip.

[0024] The needle of the present invention may include an intermediate material formed on or attached to the integral needle tip foam for heat dissipation during deposition of the first material. In other words, the needle may be formed from the first material. The intermediate layer may be formed on the first material. The second material may be formed on the second material. Three materials may be used to form a needle having a needle tip of the present invention.

[0025] The second material can be molded onto the first material.

[0026] The first material can bond to the second material during cooling or hardening of the second material.

[0027] The needle tip can include an opening to form a window for viewing the primary flashback. For example, if the needle is formed by coating a second material on a first material, it is possible to mask a portion or sections of the first material inside so that when the first material is positioned on the second material, the masked portion of the first material serves as an observation window for observing the primary flashback. The window can have a solid, non-removable surface that is transparent or semi-opaque.

[0028] The needle hub can be attached to the needle, and a tether can be connected between the needle tip and the needle hub to couple the needle tip to the needle hub.

[0029] In some examples, the needle having the needle tip can be secured to the needle hub via a needle weld. The needle can have at least two different materials. The second material can be deposited on the first material or molded into the first material, such as inside or outside the first material.

[0030] The needle shaft can include markings, which can be positioned on the needle shaft so as to be visible during primary flashback.

[0031] A catheter assembly can include a needle according to any of the embodiments described herein. The catheter assembly can include a catheter hub and a catheter tube connected to the catheter hub by a ferrule or the like and surrounding the needle.

[0032] The catheter assembly can include a valve and a valve opener disposed within the catheter hub.

[0033] The valve may include multiple slits that define multiple flaps. By way of example, the valve may include three slits and three flaps.

[0034] The valve opener can include a nose portion and two plunger elements extending proximally from the nose portion. In one embodiment, the two stabilizer elements can be connected to the two plunger elements, respectively. The two stabilizer elements and the two plunger elements can define a stabilization ring at their connection regions.

[0035] Two through openings can be provided between the nose portion and the stabilization ring. In one embodiment, the needle guard can include two elbows, each of which can be positioned within a respective through opening in the valve opener.

[0036] The catheter assembly may have a needle guard disposed within the catheter hub.

[0037] The needle guard can be located between the two plunger elements of the valve opener.

[0038] The needle includes a needle tip and a needle shaft, and the needle shaft may include markings that are visible during primary flashback.

[0039] The needles provided herein can be two-piece needles attached to each other via a coupling.

[0040] The needle is formed from a first material and is either surrounded by or supported within a second material. The first material can include a needle tip shape.

[0041] Methods of making and using needles, needle devices, and catheter devices and components thereof are within the scope of the present invention. [Brief explanation of the drawings]

[0042] Preferred embodiments of the present invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0043] [Figure 1] It's a needle. [Figure 2] FIG. 2 is a cross-sectional view of the needle shown in FIG. 1. [Figure 3] 2 is a cannula including the needle shown in FIG. 1. [Figure 4A] FIG. 1 is an exploded view of the needle. [Figure 4B] The assembled needle is shown in FIG. 4A. [Figure 5] 2 is a cross-sectional view of a needle assembly including the needle shown in FIG. 1. [Figure 6A] FIG. 1 is an exploded view of the needle. [Figure 6B] The assembled needle shown in Figure 6A. [Figure 7A] FIG. 1 is an exploded view of the needle. [Figure 7B] FIG. 7B is a cross-sectional view of the assembled needle shown in FIG. 7A. [Figure 8A] FIG. 1 is an exploded view of the needle. [Figure 8B] FIG. 8B is a cross-sectional view of the assembled needle shown in FIG. 8A. [Figure 8C]The assembled needle shown in FIG. 8A. [Figure 9A] FIG. 1 is an exploded view of the needle. [Figure 9B] FIG. 9B is a cross-sectional view of the assembled needle shown in FIG. 9A. [Figure 9C] The assembled needle shown in Figure 9A. [Figure 10] 10 is another embodiment of a needle. [Figure 11] 1 is a catheter assembly showing the catheter tube positioned over the needle. [Figure 12] 10 illustrates an alternative embodiment of a needle formed from multiple materials. [Figure 13A] 1 illustrates various methods of forming needles according to the present disclosure. [Figure 13B] 1 illustrates various methods of forming needles according to the present disclosure. [Figure 13C] 1 illustrates various methods of forming needles according to the present disclosure. [Figure 13D] 1 illustrates various methods of forming needles according to the present disclosure. [Figure 14] 1 shows a catheter assembly, needle hub, and needle according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0044] The detailed description set forth below in conjunction with the accompanying drawings is a description of presently preferred embodiments of needles and catheter assemblies incorporating the needles and components thereof provided in accordance with aspects of the device, system, and method of the present invention, and is not intended to represent the only manner in which the device, system, and method of the present invention may be constructed or utilized. This disclosure defines the features and steps for constructing and utilizing the present device, system, and method embodiments in connection with the illustrated embodiments. However, it will be understood that the same or equivalent functions and structures may be achieved by different embodiments that are also intended to be encompassed within the spirit and scope of the present disclosure. As shown elsewhere in this disclosure, like element numbers are intended to indicate like or similar elements or features.

[0045] Described herein are mixed-material needles and catheter assemblies using mixed-material needles. The mixed-material needles described herein provide a rigid, low-penetration material at the needle bevel and allow for different materials along the needle shaft or shank. Thus, the benefit of low penetration force is retained while allowing the shaft to be formed from a more cost-effective material, a material that is easily formed into a cylindrical needle shaft, and / or a material with different but advantageous properties compared to a metal needle shaft.

[0046] Advantageously, a rigid material such as metal for the needle bevel at the needle tip reduces deformation of the needle assembly upon penetration. Furthermore, it is easier to fabricate a small diameter metal bevel compared to, for example, plastic. It is also easier to obtain a sharp edge on a metal bevel, for example, by grinding or machining, compared to, for example, plastic.

[0047] Referring now to FIG. 1 , one embodiment of a needle 10 according to an aspect of the present invention is shown. The needle 10 is suitable for intravenous catheters, hypodermic needles, biopsy needles, central venous catheter (CVC) needles, blood collection needles, dialysis needles, spinal needles, and the like. It will be understood that the present disclosure is broadly applicable to needles for medical procedures and is not limited to the applications described with reference to the examples herein, nor to the particular gauge or length. The needle 10 generally comprises a sharpened needle tip 14 and a needle shaft 12. In an exemplary embodiment, the needle tip 14 is separately formed and attachable to the needle shaft 12. In use, the needle tip 14 is attached to the needle shaft 12 along an interface or attachment point to form the needle 10.

[0048] The needle 10 may be formed from one or more materials, such as plastic or metal. Furthermore, the needle shaft 12 may be defined by the length of the needle between the bevel 30 and the point at which the needle is gripped during use, or by the needle hub if the needle hub is gripped. Thus, the shaft length can be variable depending on where the needle is gripped. The needle shaft 12 may similarly be defined by the length between the bevel 30 and the needle hub 16 (FIG. 3). In a specific example, the needle shaft 12 is defined by the length between the bevel 30 and the proximal end of the needle.

[0049] If the needle 10 is movable with the needle hub 16, the needle 10 may have an extended state in which the needle 10 is positioned to penetrate the patient and a retracted state in which the needle 10 is retracted from the patient. For example, after penetrating the patient, a catheter may be advanced over the needle 10, the needle may track within the catheter, and eventually completely separate from the catheter. The needle shaft 12 may be comprised of a distal length 12a and a proximal length 12b. The distal length 12a may be the length between the bevel 30 and the hub 16. The distal length 12a may be, for example, sufficiently rigid to support the needle tip 14 during its insertion into the patient without substantial bending or curvature of the needle shaft. Excessive levels of bending or curvature may cause significant discomfort. The needle shaft 12 may also include a proximal length 12b extending proximally from the distal length 12a. The distal and proximal lengths together define the needle shaft. Thus, reference to the needle shaft may refer to only the distal length 12a or to both the proximal 12b and distal 12a lengths.

[0050] The needle tip 14 and needle shaft 12 may be supplied separately and assembled at the hospital or clinic or immediately prior to use. Alternatively, the needle 10 may be supplied as an assembled product with the needle tip 14 attached to the needle shaft 12 in the attachment position shown. The needle 10, including the needle shaft 12 and needle tip 14, can be hollow or solid, like a stylet.

[0051] In one embodiment, needle tip 14 is a hollow cylindrical body with a needle tip bevel at its distal end. Needle tip 14 has a pointed distal end 20, a bevel 30, and a cylindrical portion 21. Needle tip 14 can be considered to include a distal portion 22 and a proximal portion 24. Distal portion 22 includes distal tip 20 and cylindrical portion 21.

[0052] In some embodiments, proximal portion 24 includes a profile change 26, currently in the form of a recess, indentation, or crimp, as particularly shown in FIGS. 1 and 2. Advantageously, profile change 26 is configured to bear against the needle guard, secure the needle guard to the needle tip, cover the needle tip to prevent inadvertent needlesticks, or retract the needle guard with the needle tip after successful venipuncture, such as around a perimeter defining an opening in the needle guard. Exemplary needle guards and the engagement between profile change 26 and the needle guard are described in U.S. Patent No. 6,616,630 and U.S. Patent Publication No. 2018 / 0214682, the contents of which are expressly incorporated herein by reference. Crimp 26 may also be referred to as a recess or constriction.

[0053] The needle tip 14 has an elongated body. In one example, the elongated needle tip 14 tapers in a proximal or proximal direction. For example, the elongated body of the needle tip 14 can have an outer diameter that increases in size in a proximal direction. In some embodiments, the taper can guide insertion of the needle tip 14 into the catheter 18 prior to use. The proximal portion 24 of the needle tip 14 can be at least partially received within the catheter 18 before the catheter 18 is advanced over the needle 10 into the subject. In some examples, the distal end of the catheter 18 has a taper to guide or facilitate insertion over the needle into the patient. An opening in the distal catheter can form an interference fit around the needle tip to facilitate insertion.

[0054] In the embodiments described below in which the needle tip 14 is assembled to the needle shaft, the needle shaft 12 can at least partially protrude into the needle tip 14, or the needle tip can at least partially surround the needle shaft. In other examples, the needle tip 14 can have a proximal taper that is utilized for insertion into the needle shaft 12. In some embodiments, the taper for assembly is provided only in the proximal portion 24 of the needle tip 14.

[0055] The sharpened needle tip 14 includes a bevel 30 at the distal end 20, as discussed above. The bevel 30 may embody a standard needle bevel as known in the art. Alternatively, the distal end 20 may have an alternative needle tip, such as a coring needle tip, a different cut bevel, or a blunt needle tip, suitable for some applications. When the needle tip 14 is made of a metal material and has both a bevel and a cylindrical portion, the needle tip 14 is shorter than a conventional metal needle, such as less than 38 mm. The needle tip 14 can be coupled to a plastic needle hub 16 via the needle shaft 12. Preferably, the length of the needle tip 14, including the bevel shape, is long enough to maintain rigidity during penetration, thereby providing a low penetration force and reducing pain or discomfort to the patient during penetration.

[0056] The sharpened needle tip 14 is formed from a first rigid material. The term "rigid" in this context means that the material is more rigid than the needle shaft 12 or more rigid than a plastic material. The first rigid material can maintain the sharp edge and shape of the bevel 30 during penetration of the subject. Thus, the first material contributes little, if any, deformation at the puncture site during penetration.

[0057] The needle shaft 12 is formed from a second material. The second material may be the same as the first material, i.e., the material from which the needle tip 14 is formed. However, in the embodiments described herein, the second material is different from the first material. For example, the second material may be a plastic material or other material that has a lower rigidity than the material used to form the needle tip 14. The first and second materials may also be selected to facilitate separation of the needle tip 14 and the needle shaft 12. For example, the shaft may be formed from a plastic material that can be heated, such as in an autoclave, to become pliable or liquid, facilitating separation of the needle tip from the shaft. Alternatively, one or both of the first and second materials may be readily soluble.

[0058] The needle shaft 12 may be formed from a material that is sufficiently rigid to support the needle tip 14 without substantially deforming the needle shaft 12 during insertion of the needle tip into a patient. In some embodiments, the first material is a metallic material and the second material is a plastic material. In some embodiments, the needle shaft 12 includes spines 15 (FIG. 3), i.e., longitudinal ribs, to increase its rigidity. If incorporated, the spines 15 may be added, for example, during plastic extrusion or by overmolding if overmolding the needle shaft over a sharpened tip is practiced.

[0059] In one example, the overmolding process involves forming a component, such as a needle shaft, over another component, such as a needle tip, by using another component as part of a mold. For example, the needle tip may be formed from a first material, such as a metal material, and molded to form a mold for a portion of the needle shaft. Thus, the mold may consist of the needle tip as the outer portion of the mold and a cylindrical member or mandrel as the inner portion of the mold, forming a mold cavity therebetween. A second material may then be poured or injected into the cavity and solidified to form part or all of the needle shaft. After the second material has hardened or solidified, the cylindrical member or mandrel is then removed, resulting in a hollow needle tip with an overmolded needle shaft.

[0060] In some cases, such as when a solid needle is desired rather than a hollow needle, a cylindrical member or members are not required. When a solid needle is formed, the needle tip may form a closed end or a solid body (i.e., not hollow) even before the shaft is molded onto the needle tip. Alternatively, the needle tip may be hollow, and the shaft may fill the interior volume of the needle tip during molding. The needle tip can then be machined to form a sharpened tip, resulting in the distal end of the shaft being formed as part of the sharpened solid needle tip. In other embodiments, the needle tip and a separately formed needle shaft are connected by adhesive / coating, heat sealing, ultrasonic welding, an interference fit, or any other suitable attachment means. In yet another embodiment, the needle is formed entirely of a second material, such as a plastic material, and the needle tip is coated in or on the shaft, such as by plating or electroplating a metal onto the tip, to form a tip with more rigid properties than the uncoated portion of the needle.

[0061] The term "under-molded" can be used to refer to the same overmolding process described herein, but recognize that the needle shaft is formed under, rather than over or around, the proximal end of the needle tip. In an alternative embodiment, the needle tip may be rolled onto the needle shaft from a flat shape to a cylindrical shape.

[0062] In some embodiments, the needle 10, particularly the needle tip 14, is coated. For example, the needle 10 may be at least partially coated with an antimicrobial agent to reduce the incidence of infection at the penetration site. Antimicrobial agents usable herein include silver, gold, platinum, copper, and zinc. Antimicrobial metal compounds used herein preferably include silver or gold oxides and salts, such as silver acetate, silver benzoate, silver carbonate, silver citrate, silver chloride, silver iodide, silver nitrate, silver oxide, silver sulfadiazine, silver sulfate, gold chloride, and gold oxide. Platinum compounds such as chloroplatinic acid or its salts (e.g., sodium and calcium chloroplatinic acid) may also be used. Copper and zinc compounds may also be used, including, for example, the copper and zinc oxides and salts described above for silver. A single physiological antimicrobial metal compound or a combination of physiological antimicrobial metal compounds may be used. Alternatively, a thin layer of antimicrobial agent may be deposited on the needle wall. Another example of a coated needle 10 is an echogenic coating for improved ultrasound visibility. The needle tip 14 may also, or in addition, include markings or etchings to improve ultrasound visibility. In other embodiments, a lubricious coating is applied to the needle tip to reduce pain perceived by the patient during penetration.

[0063] Advantageously, the second material in this embodiment is a light-transmitting material to allow visual detection of primary flashback in the needle shaft. In some embodiments, the second material is translucent or semi-opaque to allow visual detection when blood is present in the needle shaft 12. The second material may alternatively be transparent.

[0064] The needle shaft 12 may be constructed from two or more materials or may have a varying composition along its length. Referring to FIG. 12, a needle 10 having two or more materials or compositions is shown. The needle 10 may include three or more distinct regions A, B, and C, each formed from a different material. In certain embodiments, regions A, B, and C have different diameters, such as different outer diameters, different inner diameters, and / or different shaft wall thicknesses. This may result in different hardnesses across the different regions. For example, region C may have a smaller diameter than regions A and B. For example, if region C extends through a septum, its reduced diameter relative to regions A and B reduces the amount of space occupied by the needle shaft protruding through the septum. Reducing the shaft diameter frees up cross-sectional space within the catheter hub. This facilitates the attachment of other components, such as a needle guard, to the interior of the catheter hub during assembly.

[0065] Region A may include a needle tip 14 formed from metal. In some examples, the needle tip 14 may be comprised of a substrate material 1306, as shown in FIG. 13A. The substrate 1306 may have a needle tip shape. That is, the substrate 1306 may have a substrate with a tubular and beveled tip shape, or both a tubular and beveled tip shape, referred to as a needle tip form 1306. The substrate needle tip shape 1306 provides a shape onto which a first material can be deposited to form the final shape of the needle tip 1304, which includes the tubular and beveled portions of the substrate and the first material deposited thereon to form the final needle tip 1304. For example, the first material can be deposited on the substrate 1306 through plating, electrolysis, electroplating, vapor deposition, or the like. Thus, the substrate 1306 can have an exterior material onto which the substrate can be deposited. The substrate 1306 may be a plastic material, such as medical-grade silicone.

[0066] 12, in some examples, the needle shaft 12 can include an integral tip feature at the distal end of the elongated tubular portion of the needle shaft. For example, the substrate onto which the first material can be deposited can include the distal end of the needle shaft 12 and the tip 14, or the needle shaft and tip form of the substrate can be attached as described elsewhere herein, the first material can be deposited onto the integral tip and shaft, or the substrate can be overmolded onto a pre-formed tip.

[0067] Region B may comprise a hard plastic material, such as a transparent material for primary flashback visibility. Region B may be the distal end 12a of the needle shaft 12. Region C may be formed using a relatively soft plastic material and may be referred to as the proximal end 12b' of the needle shaft 12. It is noteworthy that the different materials may include different compositions of the same material, such as low-density polyethylene and high-density polyethylene, different colors of materials, different light transmittances, etc.

[0068] Region B may extend proximally from region A of needle 10 to needle hub 16, and region C may form a proximal portion of needle 10 located proximal to needle hub 16. In other examples, instead of having discrete variations in material across distinct or discrete regions of needle 10, needle 10 may include one or more regions of continuous variations in material, such as a continuous spectrum from highest to lowest stiffness. For example, needle 10 may be formed from high-density polyethylene at its distal end 20 and from low-density polyethylene at its proximal end located in or proximal to needle hub 16.

[0069] In another embodiment, the proximal end of the needle shaft 12, i.e., the proximal end of region C as particularly shown in FIG. 12, is sharpened to facilitate piercing, for example, a blood collection tube. In other words, the needle 10 of FIG. 12 can be implemented as a needle having a distal tip and a proximal tip, or as a needle with two sharpened tips. Thus, in this embodiment with two tips, region C may be formed from a material with sufficient rigidity so that the sharpened proximal tip is capable of piercing the septum of a blood collection tube, otherwise known as a vacutainer. Furthermore, where region B defines the region of the needle shaft extending from the needle tip 14 and region C defines the region of the needle shaft extending distally from the proximal end of the needle shaft, there may be additional regions between regions B and C, such as regions D, E, and F.

[0070] The needle shaft 12, as particularly shown in FIG. 12, comprises a marking, hereinafter referred to as an indicator 32. The marking 32 in this embodiment develops a contrasting color or appearance when exposed to blood, allowing for easy visual identification of the indicator's display. It will be understood that each needle may be provided with one or more indicators, each having the same function as the indicator 32 described herein. The one or more indicators allow for visual differentiation between a primary flashback, indicating entry of the bevel 30 into a vein, and a secondary flashback, indicating entry of the catheter 18 into that same vein. The indicator 32 is visible during a primary flashback, when blood flows through the needle lumen. During a secondary flashback, blood in the annular space between the outer surface of the needle shaft 12 and the inner surface of the catheter 18 (see FIG. 1) obscures the indicator 32. Thus, if blood is visible in the catheter 18 but the indicator 32 is still visible, it can be visually distinguished as indicating a primary flashback. However, if the indicator 32 is no longer visible, it indicates a secondary flashback. The indicia 32 can be marked by means of laser marking, pad printing or silk screen printing.

[0071] In an embodiment, the needle 10 can be fabricated by attaching the needle tip 14 to the needle shaft 12 using a coupling, as described further below. Referring to FIG. 2 , when the needle tip 14 and the needle shaft 12 are coupled together, the inner surface 38 of the needle shaft 12 conforms to the outer surface 40 of the needle tip 14. At the interface 42 between the needle shaft 12 and the needle tip 14, the outer surface of the interface 42 is of a constant diameter or is otherwise smooth. In some embodiments, the outer diameter of the cylindrical portion 21 of the needle tip 14 may be larger than the outer diameter of the needle shaft 12. In other examples, the outer diameter of the cylindrical portion 21 of the needle tip 14 may be smaller than the outer diameter of the needle shaft 12. The transition from the needle tip 14 to the needle shaft 12, i.e., when the puncture moves from the diameter of the needle tip 14 to the diameter of the needle shaft 12, is ideally smooth enough to prevent the needle shaft 12 from catching on the target tissue during insertion of the needle 10 into the subject and to ensure that the needle tip 14 does not catch on the target tissue during retraction after successful injection or venipuncture.

[0072] In some embodiments, such as shown in Figure 2, the needle tip 14 includes a metal tube 17 having a hollow cavity 19. A catheter 18 may be disposed on the exterior of the needle and the metal tube. In some embodiments, the catheter 18 may be held against the exterior surface of the metal tube 17 and / or needle shaft 14 by frictional engagement with known catheter assemblies to prevent snagging on body tissue.

[0073] In embodiments of the present invention, various forms of coupling may be used to couple the needle tip 14 to the needle shaft 12. The particular coupling may be selected to maintain the sterility required for a particular use or application of the needle. The coupling may include one or more recesses on one of the needle shaft 12 and the needle tip 14, and a complementary protrusion on the other of the needle shaft 12 and the needle tip 14 for each recess. Each protrusion is positioned to be received in a corresponding recess, thereby coupling the needle tip 14 to the needle shaft 12. For example, for the embodiment shown in FIG. 4A, the needle shaft 12 includes one or more recesses or channels 402. The channels 402 are preferably positioned adjacent to the distal end 403 of the needle shaft 12.

[0074] In the embodiment of FIG. 4A, the needle tip 14 includes a plurality of protrusions, currently in the form of metal beveled prongs 404. The prongs 404 are preferably located at the proximal end of the needle tip 14 and are configured to fit within a complementary channel 402 in the needle shaft 12. As particularly shown in FIG. 4B, to couple the needle shaft 12 with the needle tip 14 to form the needle assembly 10, the two components are urged toward each other in directions F1 and F2, respectively, until the prongs 404 engage within the channel 402, as shown in FIG. 4A, thereby forming a coupling 85 that couples the needle tip 14 with the needle shaft 12. The prongs 404 may be biased radially inward. During insertion of the distal end 403 of the needle shaft 12 into the needle tip 14, the prongs 404 are urged radially outward against the bias of the prongs 404 until the prongs 404 are aligned with the channel 402. The pawls 404 then bias or spring back into the corresponding channels 402 to couple the needle tip 14 to the needle shaft 12. As shown, the distal end of the needle shaft 12 can be tapered to facilitate insertion into the needle tip.

[0075] In another embodiment, particularly as shown in FIG. 5 , the needle tip 14 includes a proximally extending protrusion 502. The proximally extending protrusion 502 is located at the proximal end of the needle tip 14. In this embodiment, a wire, thread, or tether 506 is used to secure the needle tip 14 to the needle shaft 12 or hub 16. Preferably, one end, e.g., a first end, of the tether 506 is welded, tied, or otherwise attached to the protrusion 502 adjacent the proximal end of the needle tip 14, or inserted through an eye 504 in the needle tip 14 and heated to form a bundle. That end, i.e., the distal end, of the tether 506 may alternatively be tethered to the needle tip 14 by a crimp, such as the crimp used to prevent the needle 10 from being drawn completely through the needle guard, and by heating the tether, as described below, to form a bundle larger than will fit through the crimp.

[0076] Preferably, the opposite end, e.g., the second end, of tether 506 is coupled to plastic needle hub 16 at point 508, as particularly shown in FIG. 5 . Point 508 comprises a slit or hole having a width or diameter that is the same as or larger than the diameter of tether 506 but smaller than the diameter of enlarged portion 510 at the second end of tether 506. In some embodiments, to secure tether 506 to plastic hub 16, the proximal or second end of tether 506 is bunched or crimped to form enlarged portion 510 large enough to move back distally through point 508. For example, tether 506 may be heated to form a bundle—some plastics are known to automatically bunch when heated—thereby coupling tether 506 to point 508 to couple needle tip 14 to plastic hub 16. When the tether 506 is entangled at a first end with the needle tip 14 and at a second end with the hub 16, the two are joined via a coupling 85 provided by the tether, which reduces the likelihood that the needle tip 14 will become detached from the needle assembly 16 when the needle is removed from the patient.

[0077] Referring to FIG. 3, a needle assembly is shown. The needle assembly includes a needle tip 14 and a needle shaft 12 coupled to a needle hub 16. In one embodiment, the needle shaft 12 is molded or formed with the needle hub 16, forming a single, integral part between the shaft and the hub. Thus, when molded as described, the needle hub 16 may comprise a portion of the needle, be attached to the needle, or be molded with the needle. The needle hub 16 may otherwise be a standard needle hub and include an elongated body for gripping. The body of the needle hub 16 may also include a hollow interior, and the open proximal end may include a hydrophobic filter.

[0078] In other embodiments, the plastic needle hub 16 is bonded to the needle shaft 12 by mechanical or fastening means to form the needle 10. In some examples, fastening means such as bonding include interference fit, friction fit, ultrasonic welding, adhesive or bonding, and other attachment methods.

[0079] In yet another embodiment, particularly as shown in FIG. 6A , the needle shaft 12 can include a protrusion or bump 604. The bump 604 can be located adjacent the distal end of the needle shaft 12. The bump 604 can embody a raised ring or two or more separate bumps. In one example, the needle tip 14 includes an internal, complementary recess 602. The recess 602 extends circumferentially around the inner surface of the needle tip 14 and is preferably located at the proximal end of the needle tip 14. Preferably, the recess 602 is formed to fit over the bump 604 of the needle shaft 12. As particularly shown in FIG. 6B , to couple the needle shaft 12 with the needle tip 14 to form the needle assembly 10, the two components are oriented toward each other in directions F3 and F4, respectively, as shown in FIG. 6A until the bump 604 is located within the recess 602, thereby forming a coupling 85 for coupling the needle tip 14 with the needle shaft 12. The bumps 604 are held in the recesses 602 by friction or an interference fit during use of the needle 10. Once joined, the recesses 602 can function as a change in profile similar to a crimp for engaging a needle guard, as previously described.

[0080] The bump 604 and needle shaft 12 can be made from a material that is relatively less hard than the material used to form the needle tip 14, for example a plastic material, such as a metallic material or a plastic material coated or plated with a hard material, so that when an opposing force is applied, the needle shaft 12 can deform to fit the opening in the needle tip 14. As shown, the distal end of the needle shaft 12 can be tapered to facilitate insertion into the needle tip.

[0081] Of course, the design of the bumps and corresponding recesses or indentations may be different, such as a circumferential rib or one or more protrusions. For example, as particularly shown in FIG. 7A, the needle shaft 12 includes a plurality of protrusions or bumps 704. The bumps 704 are preferably located at or near the distal end 706 of the needle shaft 12. In this embodiment, the needle tip 14 includes complementary openings 702 for each bump 704, preferably located at the proximal end of the needle tip 14. Preferably, the openings 702 are shaped to receive the bumps 704 on the needle shaft 12. As particularly shown in FIG. 7B, to couple the needle shaft 12 with the needle tip 14 to form the needle assembly 10, the two components are moved toward each other in the respective directions F5 and F6 shown in FIG. 7A until the bumps 704 are positioned within the openings 702, as shown in FIG. 7B, thereby forming a coupling 85 that attaches the needle tip 14 to the needle shaft 12. The bumps 704 may be irregularly spaced so that the needle tip 14 and needle shaft 12 can only mate in a single orientation. As shown, the distal end of the needle shaft 12 may be tapered to facilitate insertion into the needle tip.

[0082] As shown particularly in FIG. 8A , in yet another embodiment, the needle shaft 12 includes one or more holes 804. The one or more holes 804 are preferably located at or near the distal end of the needle shaft 12. In this embodiment, the needle tip 14 includes one or more flared fingers 802. The flared fingers 802 extend proximally from a proximal end 803 of the needle tip 14. Preferably, the flared fingers 802 are shaped to fit within one or more respective holes 804 in the needle shaft 12. As shown particularly in FIG. 8C , to couple the needle shaft 12 with the needle tip 14 to form the needle assembly 10, the two components are moved toward each other in directions F7 and F8, respectively, as shown in FIG. 8A , until the one or more flared fingers 802 are positioned within each of the holes 802, as shown in FIG. 8B , thereby forming a coupling 85 for attaching the needle tip 14 to the needle shaft 12. A rocking or wiggling motion may be employed to cause the flared fingers 802 to fit within the distal opening of the needle shaft 12 .

[0083] As particularly shown in FIG. 9A , in yet another embodiment, the needle shaft 12 includes an arm 904, which includes a pair of tines or prongs with a gap between them, each of which may include a barbed end. The arm 904 is preferably located at the distal end of the needle shaft 12. In this embodiment, the needle tip 14 includes a metal rib 902 extending inside the needle tip 14, such as an annular recess. The metal rib 902 is located near the proximal end of the needle tip 14. Preferably, the arm 904 is formed to deflect into the rib 902. This is accomplished by forming the arm 904 from two opposing halves biased to the position shown in FIG. 9A . When the arm 904 is pushed through the rib 902, the arm moves in direction F10 and the rib moves in direction F9, forcing the opposing halves of the arm 904 together, creating a radially swinging outward bias when the recess in one half of the arm 904 aligns with the rib 902, thereby coupling the needle shaft 12 to the needle tip 14. This connection defines a coupling 85 for attaching the needle tip 14 to the needle shaft 12 .

[0084] 13A-13D show alternative attachment mechanisms. In FIG. 13A, a needle shaft 1306 extends the entire length of the needle 1302, from the proximal end to the needle tip. A first material, which may be a metallic material, can then be deposited onto the needle shaft 1306 to form the needle tip 1304. The portion 1300 of the shaft 1306 proximal to the bevel may be formed from the same material as the needle shaft 1306, or may be formed from a heat-resistant or thermo-tolerant material, such as a silicone composition, that is relatively resistant to deformation during deposition of the first material during formation of the needle tip 1304. A second material may alternatively be overmolded, or in some cases undermolded, onto the needle tip 1304.

[0085] As shown in Figure 13B, a needle having a predetermined length and two needle tips 1308, 1310 may be simultaneously formed from a body of a first material 1312 by depositing the first material down a length of a tube 1314. A second material may alternatively be overmolded onto the body of the first material 1312. The two needle tips 1308, 1310 are then formed by cutting the first material 1312 diagonally, for example, along line DD, as shown in Figure 13B.

[0086] 13C, the shaft 1316 is formed around a tube 1318, or the tube 1318 is inserted into the shaft 1316. A first material is then deposited onto the shaft 1316 to form the needle tip 1320. This allows the first material to mask the front of the shaft in area 1322. The tip can then be machined to provide a sharp bevel 1324. Again, the second material can alternatively be molded or deposited onto the needle tip 1320, with the needle tip 1320 being pre-formed to have the shape shown.

[0087] 13A-13C illustrate an embodiment in which a first material is deposited on a second material to form a needle tip on an existing shaft. The second material can be a substrate onto which the first material is deposited or molded. In some cases, an intermediate material is formed on the second material to serve as an interface between the first and second materials during the deposition step of the first material. Therefore, an embodiment with an intermediate material can be considered an embodiment of a needle having three material layers: an inner or second material, an intermediate layer, and an outermost or first material. This interface may have a higher thermal resistance compared to the second material to bond with the second material and facilitate deposition of the first material onto the intermediate layer. Alternatively, the intermediate material may be electrically conductive and bonded to the second material to facilitate electrolytic deposition of the first material onto the intermediate material.

[0088] The integral needle tip shape, whether formed from a substrate independent of the needle shaft or part of the needle shaft, may be heated during deposition of a first material on the substrate so that the first material is at least partially embedded in the second material. The first material may bond to the second material during cooling or hardening of the needle tip after deposition of the first material. Preferably, depositing the first material on the needle tip should leave a portion of the needle tip exposed to form a window through which the primary flashback can be viewed. For example, the inner first material forming the substrate may be transparent or semi-opaque, and an opening or aperture may be located anywhere on the needle tip during deposition of the first material. In one example, the window may be located near the proximal end of the needle tip where the needle tip connects to or transitions into the needle shaft. This can be achieved by applying a mask over a portion of the needle tip shape to prevent deposition of the first material on the masked area. In this embodiment, exposed is understood to mean "not covered by a first material" or "masked" or "formed by masking a portion of a second material during deposition."

[0089] The needles described above have a needle shaft that forms an integral tip shape at the distal end of the needle shaft, which serves as a substrate. The final needle tip 14 is attached to the needle shaft 12 by depositing a first material on the substrate's integral tip form. To reduce the possibility of the first material peeling off from the substrate or the needle shaft, the needle shaft may include a depression or protrusion, as shown in Figures 2 and 6A, and the first material may be deposited along the length of the needle shaft from and including the bevel to at least the depression or protrusion. Similarly, a second material may be overmolded onto the tip portion that forms the depression or protrusion, filling or surrounding the depression or protrusion and hardening to form a shaft that is fixed to the tip.

[0090] Advantageously, one material is formed over the recess or protrusion of the other, meaning that they will grip together in the event of a force that might otherwise unsheath the first material from the second material.

[0091] An alternative formation method is shown in Figure 13D. In the embodiment shown, a preformed needle tip 1326 is provided and a tube 1330 is inserted into the preformed needle tip 1326. A cavity 1328, which may be generally cylindrical, is then formed between the tube 1330 and the preformed needle tip 1326. A second material is then flowed, injected, or otherwise driven or deposited into the cavity 1328, such as by using overmolding techniques described elsewhere herein, to form the needle shaft.

[0092] As shown in FIG. 13D , the preformed needle tip 1326 can include one or more protrusions 1332. The protrusions 1332 can be directed inward into or toward the cavity 1328. The protrusions 1332 can extend radially inward. Each of the protrusions 1332 can be formed as a circumferential rib or as individual protrusions spaced apart around the circumference of the preformed needle tip 1326. The protrusions can embody a spirally formed or spiral rib material formed inward from the outer surface of the preformed needle tip. The protrusions 1332 prevent the preformed needle tip 1326 from slipping off the distal end of the finished needle shaft after formation of the needle shaft.

[0093] In a further embodiment, the needle assembly 10 includes an echogenic pattern or strip 1002, as particularly shown in Figure 10. The strip 1002 reflects ultrasound signals to provide an indication of the position of the needle 10 during ultrasound-guided insertion. The echogenic pattern or strip may be provided on the shaft or needle tip 14 for ultrasound-guided insertion of a peripheral intravenous catheter (PIVC).

[0094] FIG. 11 shows the needle assembly 10 of FIG. 10 with a catheter 18 positioned over the needle 10. The catheter 18 can be attached to a catheter hub via a ferrule or bushing. The catheter hub can optionally include a valve, valve opener, and needle guard within the hollow interior of the catheter hub. In this embodiment, the echogenic strip 1100 also functions as an indicator when exposed to blood, similar to the indicator 32 of FIG. 12, such that the strip 1100 is visible during primary flashback and is obscured or obstructed by blood within the catheter during secondary flashback.

[0095] FIG. 14 is a schematic cross-sectional perspective view of a catheter assembly 1400 incorporating the needle 10 described with reference to FIGS. 1-13. The catheter assembly 14 includes the needle 10, a catheter hub 1402, and a catheter 18. The catheter 18 is connected to the catheter hub 1402 by a ferrule 1500 or the like, surrounding the needle 10. The catheter hub 1402 is shown with wings 1502. The catheter assembly 1400 can be used in a standard manner. A valve 1504, a valve opener 1506 for opening one or more flaps, e.g., three flaps, on the valve 1504, and a needle guard 1508 may be disposed within the interior space of the catheter hub 1402, as described in U.S. Patent Publication No. 2018 / 0214682, the contents of which are expressly incorporated herein by reference. Also shown is a removable protective cap 1510 and a gas or air vent 1512.

[0096] The catheter 18 can be transparent or translucent. Markings or indicia 32 can be placed on the needle 10 so as to be obscured by bodily fluids during secondary flashback, as discussed above.

[0097] In some embodiments, the catheter assembly 1400 includes a conduit or port for coupling a valve for selectively fluidly connecting the catheter to a receptacle. For example, the catheter hub can be an integrated catheter having a port, a tube attached to the port, and a needleless connector connected to the opposite end of the tube. Alternatively, the catheter hub can be a ported catheter in which the port can directly accept a needle tip or male luer tip without a tube. The catheter assembly can also include a needle guard for guarding the needle tip 14, as described in U.S. Patent Publication No. 2018 / 0214682, to prevent needlestick injuries after use.

[0098] In another embodiment, the catheter assembly 1400 further includes a blood septum control mechanism. Preferably, the blood septum control mechanism is a valve having multiple slits defining multiple flaps. The valve can be selectively in an open or closed position. For example, the valve flaps close the valve when the needle is retracted to stop blood from flowing out of the catheter hub, and the flaps open the valve when a connection is made with an external receptacle, such as when a needle tip or IV adapter is inserted into the proximal opening of the catheter hub, which may embody a female luer or a threaded female luer.

[0099] Of course, the shape of the needle shaft 12 can be, for example, hollow, solid, or semicircular. The profile of the needle shaft 12 can be tailored to suit the requirements of a particular application. Advantageously, in embodiments in which the needle shaft 12 is solid, manufacturing the needle shaft 12 can be easier and less expensive than manufacturing a hollow needle shaft, such as using a mold to form the shaft. However, such a configuration has the disadvantage that secondary flashback may not be visualized. Primary flashback may be visualized by including a notch or groove on the needle shaft 12, such as a longitudinal groove (i.e., extending along the needle) extending from a position at or near the needle tip to a position outside the patient during needle insertion.

[0100] Advantageously, embodiments of the present invention allow for low puncture force penetration into the patient while providing high flashback visibility via visual feedback through the needle's surface layer. By incorporating plastic into the needle, embodiments of the present invention reduce the percentage of metal in the needle, lowering costs. Additionally, using both plastic and metal allows manufacturers flexibility in how the needle is formed. Maintaining the needle tip as metal advantageously results in less discomfort for the subject.

[0101] Additionally, in some embodiments, some portions of the needle that are plastic can be transparent. The use of transparent plastic facilitates visualization of primary flashback in the needle shaft without the need for either a window / notch formed in the needle or blood exiting the proximal end of the needle.

[0102] Advantageously, embodiments of the present invention provide a solution to space limitations in catheters, such as intravenous catheters. Some features typically heavily relied upon in the plastic catheter hub of conventional systems result in severe space limitations. Embodiments of the present invention allow such features to be transferred to the plastic needle 12 instead. In other words, the needle shaft can be molded with a reduced diameter section, providing space for other components to utilize the space vacated by the reduced diameter needle section. Examples of such features include safety mechanisms such as blood control septa and safety clip minimum diameters.

[0103] Throughout this specification, unless the context requires otherwise, the word "comprise," and variations such as "comprises" and "comprising," will be understood to mean the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of other integers or steps or group of integers or steps. The words "having" or "including" may have a similar meaning. Furthermore, features from different embodiments may be combined with other embodiments, and features may be substituted for or eliminated from one another, without departing from the present teachings.

[0104] The reference herein to any prior art is not an acknowledgement, nor is it to be taken in any way as an indication, that the prior art forms part of the general general knowledge.

[0105] The use of "first" and "second" is intended only to distinguish between two different items or components and is not intended to be limiting, unless the context indicates otherwise.

[0106] Methods of making and using multi-piece needles, as well as catheter assemblies and components thereof, are within the scope of the present invention.

[0107] While limited embodiments of needle and catheter assemblies and their components have been specifically described and illustrated herein, numerous modifications and variations will be apparent to those skilled in the art. It is therefore understood that needle and catheter assemblies, and their components, constructed in accordance with the principles of the disclosed devices, systems, and methods may be embodied other than as specifically described herein. The present disclosure is also defined in the following claims.

Claims

1. a needle tip (14) formed from a first rigid material and including a bevel (30) for puncturing a target; and a needle shaft (12) comprising a second material, The needle tip (14) is formed separately and then attached to the needle shaft (12) to form the needle (10); The second material is a light-transmitting material to allow visual detection of the primary flashback in the needle shaft (12), the needle (10); a catheter hub (1402); and A catheter assembly (1400) including a catheter (18) connected to a catheter hub (1402) and surrounding a needle (10).

2. The catheter assembly (1400) of claim 1, wherein the first material has a higher stiffness than the second material.

3. The catheter assembly (1400) of claim 1 or 2, wherein the first material is a metal.

4. The catheter assembly (1400) of any one of claims 1 to 3, wherein the second material is plastic.

5. The catheter assembly (1400) of any one of claims 1 to 4, wherein the second material is transparent or translucent.

6. A catheter assembly (1400) according to any one of claims 1 to 5, wherein the needle tip (14) is attached to the needle shaft (12) via a coupling (85).

7. Coupling (85) is one or more depressions in one of the needle shaft (12) and the needle tip (14); and A catheter assembly (1400) as described in claim 6, including a protrusion corresponding to each recess, provided on the other of the needle shaft (12) and the needle tip (14), and positioned to be received in the recess, thereby connecting the needle tip (14) to the needle shaft (12).

8. Coupling (85) is one or more openings (702) in one of the needle shaft (12) and the needle tip (14); and A catheter assembly (1400) as described in claim 6 or 7, comprising, for each opening (702), a protrusion (704) provided on the other of the needle shaft (12) and the needle tip (14), arranged to be received in the opening (702), thereby connecting the needle tip (14) to the needle shaft (12).

9. The needle tip (14) is a first material having a bevel (30); and Either (i) a second material is formed on a first material, thereby forming a needle shaft (12); or (ii) a needle shaft (12) is formed from a second material and then connected to the first material; The catheter assembly (1400) of any one of claims 1 to 8, comprising:

10. A catheter assembly (1400) as described in any one of claims 1 to 9, wherein the needle shaft (12) includes an integral needle tip (14) at the distal end of the needle shaft (12), and the needle tip (14) is attached to the needle shaft (12) by depositing a first material onto the integral needle tip foam (1306).

11. The needle tip (14) is a proximal end including one of a recess and a protrusion; A catheter assembly (1400) as described in any one of claims 1 to 10, wherein forming the second material on the needle tip (14) includes depositing the second material from a location distal to the depression or protrusion to and past the proximal end of the needle tip (14) along the length of the needle tip (14).

12. A catheter assembly (1400) as described in claim 10 or 11, further comprising an intermediate material formed on or attached to the integrated needle tip shape for heat dissipation during deposition of the first material.

13. The catheter assembly (1400) of any one of claims 9 to 12, wherein the second material is formed by molding onto the first material.

14. The catheter assembly (1400) of any one of claims 9 to 13, wherein the first material is bonded to the second material during cooling or hardening of the second material.

15. A catheter assembly (1400) according to any one of claims 9 to 14, wherein the needle tip includes an opening forming a window for viewing the primary flashback.

16. a needle hub (16); and A catheter assembly (1400) as described in any one of claims 1 to 15, further comprising a tether (506) connected between the needle tip (14) and the needle hub (16), connecting the needle tip (14) to the needle hub (16).

17. A catheter assembly (1400) as described in any one of claims 1 to 16, wherein the needle shaft (12) includes a marking (32), the marking (32) being positioned on the needle shaft (12) so as to be visible during primary flashback.

18. A catheter assembly (1400) according to any one of claims 1 to 17, wherein the needle (10) comprises a needle tip (14) and a needle shaft (12), and the needle shaft (12) comprises a marking (32) that is visible during primary flashback.

19. 20. The catheter assembly (1400) of claim 18, wherein the catheter (18) is transparent or translucent and the markings (32) are obscured by body fluids between the catheter and the needle shaft during secondary flashback.

20. The catheter assembly (1400) of any one of claims 1 to 19, further comprising a needle hub (16) attached to the needle (10).

21. A catheter assembly (1400) according to any one of the preceding claims, wherein the needle hub (16) is integrally formed with the needle (10).

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