1. Field of the Disclosure
The present subject matter relates to a medical needle assembly of the type commonly used in blood collection or withdrawal systems. More particularly, the present disclosure relates to a needle cover for use in a medical needle assembly according to the foregoing recitation.
2. Description of Related Art
Blood collection sets, in their most basic form, typically include a collection container for receiving blood from a donor and a tube that provides a flow path from the blood donor to the collection container, the tube terminating in a needle for withdrawal of blood from a donor or patient. The needle assembly typically includes a needle or cannula attached to a needle hub which allows for manipulation of the needle assembly by the phlebotomist, nurse, or other medical professional.
Such needles are commonly shielded with a removable needle cover. Shielding the needle protects the medical professional from inadvertent contact with the sharpened needle tip. Shielding the needle also protects the needle from damage during shipping and transport. Shielding also preserves the sterility of the needle prior to use and ideally maintains the integrity of a closed blood collection system by preferably providing a hermetic seal between the needle cover and needle assembly. The needle cover may also optionally provide assurance to the end user that the needle has not been tampered with.
Examples of needle assemblies including associated needle covers are provided in U.S. Pat. Nos. 4,402,682 and 4,496,352, both of which are hereby incorporated herein by reference. These patents disclose a needle assembly including a cannula attached to a base and to donor tubing. The needle covers are made of a plastic material, which forms a thermal bond with the base to provide a tamper evident seal. The needle covers described in the above-referenced patents also include an internal plug within the bore of the needle cover and located at the distal end of the needle cover. The plug is made of a resilient material and includes a pocket for enveloping and protecting the distal needle tip.
Another example of a needle assembly and associated needle cover is disclosed in U.S. Pat. No. 4,551,138, which is hereby incorporated herein by reference. The needle cover disclosed therein includes a hollow body made of a sterilizable plastic material. The needle cover includes a resilient “layer” made of a polymeric elastomer located near the proximal open end of the needle cover. The diameter of the cylindrical resilient layer at the proximal end of the cover has a diameter that is smaller than the diameter of the needle post engaged by the needle cover. The needle cover is placed over the needle and engages the post of the needle hub. According to U.S. Pat. No. 4,551,138, a hermetic seal is formed between the needle cover and the hub or post portion of the needle assembly.
There are several aspects of the present subject matter which may be embodied in the devices and systems described and claimed below. These aspects may be employed alone or in combination with other aspects of the subject matter described herein.
In one aspect, a medical needle assembly comprises a cannula, a base secured to the cannula, and a needle cover. The needle cover comprises a hub portion adapted to be secured to the base. The hub portion includes a pair of outwardly extending wings and a raised orientation member, with the wings being foldable to overlay the raised orientation member and contact the raised orientation member and each other.
In another aspect, a medical needle assembly comprises a cannula, a base secured to the cannula, and a needle cover. The needle cover comprises a hub portion adapted to be secured to the base. The hub portion includes a bottom surface, a pair of sidewalls extending from the bottom surface, and a pair of guidewalls extending toward each other from upper ends of the sidewalls. The hub portion further includes a pair of wings extending outwardly from the sidewalls, with the wings being foldable to overlay at least a portion of the guidewalls and contact the guidewalls and each other.
In yet another aspect, a medical needle assembly comprises a cannula, a base secured to the cannula, a winged attachment piece, and a needle cover. The winged attachment piece comprises a ring portion and a pair of wings extending from the ring portion. The needle cover comprises a hub portion secured to the base. The ring portion is rotatably received on a portion of the hub portion and an outwardly extending anti-rotation member of the hub portion cooperates with the ring portion to limit rotation of the winged attachment piece with respect to the hub portion.
The embodiments disclosed herein are for the purpose of providing the required description of the present subject matter. These embodiments are only exemplary, and may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting the subject matter as defined in the accompanying claims.
The cannula 20 (shown more particularly in
The cannula 20 is attached to a post or base 22. The base 22 is a generally tubular member that includes a bore 32 (
As shown in
The proximal end 42 of the base 22 is adapted to form a liquid-tight connection with tubing 14 for association of the medical needle assembly 12 with a blood collection container or set. The base 22 may include a radial flange or abutment 44 against which the tubing 14 abuts when properly connected, thereby providing a visual indication that the tubing 14 is fully installed. In the illustrated embodiment, as best seen in
As for the needle cover 24 (
The hub portion 26 is intended to be gripped during use of the medical needle assembly 24, so it may be advantageous for it to be compact and easily manipulated between the fingertips of the phlebotomist. For example, the illustrated hub portions include concave sidewalls 50 which allow for comfortable gripping with the thumb and forefinger. The sidewalls 50 may further include gripping members 52 on the surfaces thereof. The gripping members 52 may be molded or embossed projections on the surfaces of the sidewalls 50 that affect the contour thereof. In the illustrated embodiments, the gripping members 52 are configured as spaced apart raised ribs on the sidewalls 50. An enhanced gripping surface can also be provided by other means, such as by treating the sidewalls to make them coarser or less smooth.
Other hub portion configurations may also be employed without departing from the scope of the present subject matter. For example, U.S. Patent Application Publication No. 2006/0089599, which is hereby incorporated herein by reference, shows and describes a number of alternative hub portion configurations.
In one embodiment, which is shown in
The hub portion 26 includes an inner bore 56 (
As described above, the respective flat portions 38 and 60 of the base 22 and the hub portion 26 must be aligned for the base 22 to be fully inserted within the inner bore 56 of the hub portion 26. In the illustrated embodiments, the flat portion 60 of the hub portion 26 is aligned with the indicia 54 on the outer surface of the hub portion 26, while the flat portion 38 of the base 22 is aligned with the heel 40 of the beveled end 30 of the cannula 20. Therefore, alignment of the flat portions 38 and 60 effectively aligns the indicia 54 and the heel 40. It will be appreciated that, by such a configuration, the indicia 54 acts as a bevel indicator and a phlebotomist can ascertain the orientation of the beveled end 30 of the cannula 20 by simply referring to the position of the indicia 54 on the hub portion 26.
Turning now to the cap portion 28, the illustrated embodiment is tapered as it extends from an open proximal end 62 adjacent to the hub portion 26 to a closed distal end 64. An inner cavity 66 of the cap portion 28 (
The outer surface of the cap portion 28 may include at least one outwardly extending wing 68. The illustrated cap portion 28 defines a central longitudinal axis and a pair of wings 68 extending generally radially away from the central axis. In one embodiment, the wings 68 extend away from the central axis in generally opposite directions, such that they are substantially coplanar. Rising above the surface of each wing 68 is an enlarged rib 70 (
The cap portion 28 may also include at least one annular raised rib 74 that is positioned in a plane substantially perpendicular to the central axis. In the illustrated embodiments, the cap portion 28 includes a plurality of annular ribs 74 that are longitudinally spaced from each other. As will be described in greater detail herein, after breaking of the frangible portion 48, the cap portion 28 is moved distally to separate it from the remainder of the needle cover 24, thereby exposing the beveled distal end 30 of the cannula 20, and the annular ribs 74 function to provide a gripping surface when so removing the cap portion 28.
As for the frangible portion 48, it may be provided as a relatively weak section proximal the cap portion 28. In the illustrated embodiments, the frangible portion 48 is provided as a necked-down section of relative thin thickness intermediate the cap portion 28 and the hub portion 26. In accordance with the foregoing description, the cap portion 28 is adapted to be separated and removed from the remainder of the needle cover 24, and the frangible portion 48 is broken to allow the cap portion 28 to be so removed.
In one embodiment, the frangible portion 48 is adapted to break upon application of a torsional force. Such force is typically applied by gripping the hub portion 26 with one hand, gripping the cap portion 28 with another hand, and rotating the hub portion 26 and the cap portion 28 in opposite directions about the central axis defined by the cap portion 28. As described above, the wings 68 and (in particular) the enlarged ribs 70 are configured to be gripped during application of such torsional force, and it will be appreciated that positioning each enlarged rib 70 at the outer edge 72 of the associated wing 68 provides for a relatively large moment arm, thereby decreasing the force that must be applied by the phlebotomist to break the frangible portion 48. To minimize user discomfort, it may be further advantageous to provide a frangible portion 48 that is adapted to break upon application of a torsional force in the range from about 2 to about 24 in-ounces and upon less than about 90° relative rotation between the hub portion 26 and the cap portion 28. Additionally, as shown in
The hub portion 26, cap portion 28, and frangible portion 48 may be integrally formed or, as in one embodiment, molded as a single piece. If so configured, it may be advantageous to construct the needle cover 24 from a material that: (1) is sufficiently rigid to minimize the bending of the underlying cannula 20, (2) is suitable for allowing the frangible portion 48 to be broken under the aforementioned conditions, and/or (3) has a moisture vapor transmission rate sufficient for steam sterilization of the beveled distal end 30 of the cannula 20 when it is enclosed by the cap portion 28 (e.g., a moisture vapor transmission rate in the range from about 30 to about 90 g/m2/day at approximately 38° C. at 100% relative humidity). More particularly, it may be advantageous to make the hub, cap, and frangible portions of a plastic material, such as a material having a hardness in the range from about 35 to about 65 on the Shore D durometer scale, a torsional modulus in the range from about 30 to about 80 MPa, and/or a Young's modulus in the range from about 15 to about 260 MPa. Even more particularly, it may be advantageous to provide a plastic material having a hardness less than 55 on the Shore D durometer scale. More particularly still, it may be advantageous to provide a plastic material having a hardness of about 47 on the Shore D durometer scale.
An additional property that may be advantageous for the needle cover material to possess is translucence or, even more advantageously, substantial transparency. Such a material allows the beveled distal end of the cannula to be seen through the cap portion and allows the base to be seen through the hub portion (
One plastic material that has been found to possess these advantageous characteristics is the polyamide material marketed under the name VESTAMID® E47-S1 by Evonik Degussa GmbH of Essen, Germany. However, those of ordinary skill in the art will recognize that other materials may also be used, particularly if performance characteristics different from those recited herein are desired.
In other embodiments, the various sections of the needle protector may be comprised of different materials. For example, the hub portion may be formed from a softer material than the cap portion to provide different tactile and handling characteristics. Further, the construction of any portion of the needle protector is not limited to a single material. For example, the hub portion or the cap portion could include one or more sections formed from a material having a particular rigidity or translucence or transparency and one or more other sections formed from another material having different characteristics.
The base 80 may include retention members, such as interfering surfaces, adapted for securing it to a portion of the needle cover 82. In the embodiment illustrated in
To ensure a particular annular or angular orientation of the base 80 and cannula 78 within the needle cover 82, the base 80 and needle cover 82 may be provided with cooperating indexing surfaces or features. For example, in the embodiment of
In another approach to orienting the cannula within the needle cover, illustrated in
The proximal end 104 of the base 80/80a is preferably adapted to form a liquid-tight connection with tubing (not illustrated) for association of the medical needle assembly 82/82a with a blood collection container or set, as described above for the embodiments of
As for the needle cover 80 (
Each illustrated foldable wing 106 may include a line of weakness such as a relatively thin and flexible section 108 extending outwardly from the hub portion 84 to a thicker grasping portion 110 to allow bending or folding of the foldable wing 106. The aforementioned polyamide material is sufficiently flexible to allow the foldable wings 106 to bend at the flexible sections 108 and press the grasping portions 110 against each other (
To assist in grasping and rotationally orienting the beveled distal end 88 of the cannula 78, the hub portion 84 may be provided with a configuration shape that the foldable wings 106 may contact when folded. For example, as shown in
The illustrated sidewalls 400 are generally perpendicular to the bottom surface 120, generally planar, and generally parallel to each other. At the upper ends of the sidewalls 400, there is an angular transition between the sidewalls 400 and the guidewalls 402. The transition between the sidewalls 400 and the guidewalls 402 may be either continuous (i.e., smoothly curved) or more pronounced (e.g., forming a defined edge or angle therebetween). The guidewalls 402 are angled toward each other to meet at the bevel indicator 112. In the illustrated embodiment, the guidewalls 402 are substantially planar to present the illustrated pentagonal or “home plate”-shaped cross-section, but other configurations are also within the scope of the present disclosure, such as guidewalls that are concave or convex from an end view.
The intersection of the guidewalls 402 at the bevel indicator 112 may be either continuous (i.e., curved) or discontinuous (e.g., forming a defined edge or angle or flattened section therebetween), thereby allowing for a variety of different bevel indicator configurations. For example,
The “steeple” configuration is merely illustrative and other hub portion configurations including a raised orientation member or non-circular wing-guiding member may be employed without departing from the scope of the present disclosure. Benefits of a hub portion with a raised orientation member or non-circular wing-guiding member include providing a more rigid surface than the foldable wings 106 when applying the torque required to break the frangible portion 90. The ability to press the wings 106 against the orientation member provides a more solid feel for the user when attempting to grasp the wings 106 and properly position the beveled distal end 88 of the cannula 78 prior to venipuncture. Further, the raised orientation member provides an additional contact point on the hub portion 84 during manufacturing when the cannula 78 and base 80 are pressed into the needle cover 82.
The grasping portions 110 may be provided with a slide resistance or interlock features to prevent the grasping portions 110 from sliding relative to each other when pressed together. In the illustrated embodiment, one interlock feature (indicated at 114) is generally concave and the other interlock feature (indicated at 116) is generally convex to fit together when the grasping portions 110 are pressed together for manipulation of the needle assembly 76 during phlebotomization. With the grasping portions 110 pressed together (
To provide additional traction for the fingers of the phlebotomist, the underside of one or both of the grasping portions 110 may be provided with anti-slip features. For example, in the embodiment of
When the beveled distal end 88 of the cannula 78 is properly positioned within the vein, the foldable wings 106 may be released, allowing them to return substantially to their original configuration due to material memory. Thereafter, the foldable wings 106 may be secured to the skin, e.g., the arm of the patient/donor, in a manner well known to those of skill in the art.
In addition to the foregoing, the hub portion 84 may be provided with a bottom surface 120 that is angled with respect to the central axis of the cannula 78 (
In another embodiment, illustrated in
In accordance with the embodiments described previously, the cannula 126 and associated base 128 are inserted into the needle cover 124, but in the embodiment of
The hub portion 132 and/or the base 128 may be provided with features adapted to prevent or restrict free relative movement of the winged attachment piece 130. For example, in the embodiment of
Together, the lip 138 and the collar 140 prevent the winged attachment piece 130 from sliding longitudinally with respect to the rest of the needle assembly, while allowing the winged attachment piece 130 to rotate with respect to the rest of the needle assembly. Rotation of the winged attachment piece 130, and the foldable wings 134 in particular, may be advantageous after the foldable wings 134 have been secured to the arm of a donor or patient. If blood flow from the vein slows, for example due to the beveled distal end of the cannula being pressed against the vein wall, the cannula may be rotated with respect to the foldable wings to improve blood flow out of the vein. In this manner, the foldable wings 134 may remain secured or taped to the patient's skin and the medical practitioner can still adjust the position of the needle bevel.
On the other hand, while it may be advantageous for the winged attachment piece 130 to be rotatable with respect to the rest of the needle assembly after the foldable wings 134 have been secured to a donor or patient, it may be disadvantageous for them to rotate prior to the initial phlebotomization. If the frangible portion 148 of the needle cover 124 is adapted to break upon application of torque thereto for removing the cap portion 146 and exposing the tip of the cannula 126 (
For example,
The needle assembly 200 of
In the embodiment of
The winged attachment piece 202 is rotatable about the hub portion 204, with the hub anti-rotation member 206 moving within the groove 208 (if provided) until it abuts an end of the groove 208. Accordingly, it may be advantageous for the groove 208 to be substantially wider than the hub anti-rotation member 206 to allow a greater degree of rotation once the foldable wings 216 have been secured to the donor or patient.
However, as described previously, it may be disadvantageous for the foldable wings 216 to rotate prior to the initial phlebotomization, particularly when the user is attempting to apply sufficient torque so as to break the frangible portion 218 of the needle cover 220 and expose the tip of the cannula 214. To prevent such free rotation prior to phlebotomization, the hub anti-rotation member 206 selectively engages a portion of the winged attachment piece 202 in a rotationally fixed manner. In the illustrated embodiment, this is achieved by pinching the foldable wings 216 of the winged attachment piece 202 together to trap the hub anti-rotation member 206 therebetween (
When the cap portion 222 has been broken away from the remainder of the needle assembly 200, the donor or patient is phlebotomized and the wings 216 may be released and subsequently secured to the body. With the wings 216 so released, the hub portion 204 is again free to rotate with respect to the winged attachment piece 202, thereby allowing the phlebotomist to adjust the location of the bevel end 212 of the cannula 214 within the vein.
The embodiment of
Alternatively, rather than having the winged attachment piece 150 initially associated with the hub portion 152, it may be initially provided separate therefrom (
The illustrated winged attachment piece 300 has a centrally positioned cavity 306 (
Alternatively, rather than having the winged attachment piece 300 initially separate from the hub portion 304, it may be initially connected thereto (
In yet another embodiment, illustrated in
As described above, the winged attachment piece 158 is relatively elongated, the reason being so that it may enclose a portion of the cannula 164 while remaining at least partially associated with the hub portion 166. To ensure that the winged attachment piece 158 remains in the shielding condition of
Medical needle assemblies according to the foregoing description have particular applicability to blood collection and processing systems. For example, it is contemplated that such a medical needle assembly could be incorporated into any of the various BLOOD-PACK® Units marketed by Fenwal, Inc. of Lake Zurich, Ill. However, needle assemblies according to the foregoing description are not limited to a particular use or range of uses, a particular needle gauge or configuration (e.g., the present disclosure may be employed with a cannula having a back-eye) and it is contemplated that such medical needle assemblies could be incorporated in any system and assembly involving needle entry into the vascular system of a patient or donor.
One obstacle to ready incorporation of needle protectors according to the present disclosure into both manual systems and automated systems is the fact that they typically employ different needles. Automated blood extraction system typically employ a relatively small gauge fistula needle because blood is actively pumped or drawn from a donor or patient, as opposed to manual applications in which the rate of blood removal is dictated by the donor or patient's blood pressure and a larger gauge phlebotomy needle is employed. While this difference in needles may be accommodated by providing differently sized or configured needle protectors, a single needle protector may be employed with both types of needles if a larger gauge fistula needle (i.e., one having the same gauge as a typical phlebotomy needle) can be provided.
According to one aspect of the present disclosure, a larger gauge fistula needle is provided without sacrificing flow capacity. This may be achieved by various means, but in an exemplary embodiment, the flow capacity of the fistula needle is increased by reducing the flow resistance, specifically by decreasing the overall length of the needle. An illustrative example of such an improved fistula needle follows, but those having skill in the art will appreciate that the principle described herein may be employed with a phlebotomy or fistula needle of any gauge.
A beveled cannula tip having a primary bevel 170 and a secondary bevel 172 is generically illustrated in
A known 17-gauge phlebotomy needle has an overall length of approximately 2.695 inches, with an outside diameter of approximately 0.058 inch and an inside diameter of approximately 0.050 inch. The primary bevel 170 has a length of approximately 0.209 inch and the secondary bevel 172 has a length of approximately 0.129 inch. Such a needle has a theoretical flow rate of approximately 50.72 ml/min and a measured flow rate of approximately 47.3 ml/min under comparable flow pressures. Hence, such a 17-gauge needle experiences an approximately 23.4% flow reduction as compared to the aforementioned 16-gauge needle.
To provide a 17-gauge fistula needle having similar flow capacity to the known 16-gauge needle, the overall length of the needle is reduced. For example, a 17-gauge needle may be provided with an overall length of approximately 1.665 inches, with an outside diameter of approximately 0.058 inch and an inside diameter of approximately 0.050 inch. The primary bevel 170 may have a length of approximately 0.186 inch and the secondary bevel 172 may have a length of approximately 0.072 inch. Such a needle has a theoretical flow rate of approximately 64.31 ml/min and a measured flow rate of approximately 60.5 ml/min, which is substantially the same as the aforementioned 16-gauge needle in comparable flow pressure conditions. Although the inside diameter of such a needle is smaller than the inside diameter of the known 16-gauge needle, the reduced length offsets the pressure drop to allow for similar flow capacity.
In additional to the functional advantages of this improved 17-gauge fistula needle, there are other advantages as well. First, such a needle has the same gauge as a known phlebotomy needle so, when compared to needles having different gauges, the two needles may be more easily employed with needle protectors according to the present disclosure. Second, such a needle decreases donor anxiety because it is shorter and has a smaller outside diameter. Additionally, donor discomfort is also decreased, because the smaller gauge results in a smaller vein puncture site.
It will be understood that the embodiments described above are illustrative of some of the applications of the principles of the present subject matter. Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the claimed subject matter, including those combinations of features that are individually disclosed or claimed herein. For these reasons, the scope hereof is not limited to the above description but is as set forth in the following claims.
This application is a continuation-in-part application of U.S. patent application Ser. No. 12/013,844, filed Jan. 14, 2008. This application claims priority from and the benefit of provisional patent application Ser. No. 61/040,206, filed Mar. 28, 2008, and provisional patent application Ser. No. 61/074,360, filed Jun. 20, 2008. Each of these applications is hereby incorporated herein by reference.
Number | Date | Country | |
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61040206 | Mar 2008 | US | |
61074360 | Jun 2008 | US |
Number | Date | Country | |
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Parent | 12013844 | Jan 2008 | US |
Child | 12412626 | US |