Needle protector sheath

Abstract: A needle protector sheath comprises a body having a top wall, sidewalls and open ends. A slot is formed in each sidewall to slidingly receive a needle wing extending through each of the slots. Typically the slots extend through one end of the protector sheath. The protector sheath also defines an open, bottom aperture extending from end to end of the body, to permit the sheath to be laterally applied to tubing connected to a winged needle and to be advanced to a position where the needle tip is recessed in the sheath and the needle wings extend through the slots. In another embodiment an elongated anchor member may extend forwardly from the body to be manually pressed to retain the protector sheath as the needle is being withdrawn from the skin of a patient. The anchor member may have an outer end portion that bends away from the patient in position of use. Also, a novel sheath design and slot arrangement is disclosed.

Description: BACKGROUND OF THE INVENTION US-A-5112311 of Utterberg at al discloses a protector sheath showing the features of the preamble of claim 1. Especially, it discloses a sliding body or sheath which is carried on a tubular set such as a fistula set for hemodialysis, having a winged needle at the end. There is a significant need to provide the maximum amount of protection to medical personnel against needle sticks, especially with respect to needles that are used in contact with blood. The sliding sheath of the cited patent can be brought forward to enclose the needle as the needle is retractea from the patient, so that the needle is immediately secured against accidental needle sticks by the sliding device. The wings of the needle, which are commonly used in conjunction with a variety of intravenous needles, slide within opposed slots of the needle protector of the cited patent, and are locked in place when the needle is fully withdrawn into the sliding sheath as described. Furthermore, the above prior art discloses an elongated anchor member extending forwardly from the body of the protector sheeth. This anchor member being pressed against the patient is flexible and can be positioned flat against the patient's skin. Given an angled orientation of the needle with respect to the skin, though not explicitely mentioned or shown, the tip of the anchor must be caused to bend somewhat away from the patient's skin in a curved shape. It is an object of the present invention to provide an improved medical needle protector sheath with an anchor member that can easily slide over adjacent bandages and the like when the sheath is advanced toward the needle. This object is solved by the subject matter of claim 1 as outlined further below. The outer end portion of the inventional anchor member is bent upwardly in its normal configuration (already prior to contact with the patient) and outwardly from the sheath body as well as away from the patient when the protector sheath is placed on the patient in position of use. Advantageous further developments are defined in the subclaims. By this present invention, further improvements are provided to the device disclosed in the above-cited patent. Specifically, the device of the prior art is typically placed on a needle set prior to use and the wings engaged in the slots. Even when the sliding sheath is retracted away from the needle as much as possible, medical personnel have found its presence to be inconvenient during the process of venipuncture and taping of the needle wings to the skin of the patient. Also, by this Invention, improvements in functioning are achieved by a modification of the shape of the slots of the sliding sheath or body through which the needle wings penetrate. Particularly, withdrawal of the needle from the patient can be facilitated in an axial movement, reducing the potential for the point to cause a hematoma. Also, advancement of the sheath about the needle is facilitated. Thus, significantly improved needle protector sheaths are provided, some of which can be applied to a needle and attached tubing after the needle has been inserted into the vein of a patient. Additionally, other improvements over the prior art are found herein. It also is desirable for the slots of the protector sheath body to extend toward the sheath bottom as they extend toward an open slot end at one end of the body. This has been found to facilitate the easy withdrawal of a needle emplaced in the venous system of a patient, with the needle tip directed in the direction of the one end of the body. As the needle is withdrawn, the needle protector can receive the needle wings in the slots. Because of the curve of the slots toward the bottom of the body, the needle wings are more easily received and engaged by the slots as the needle is withdrawn, with the needle protector sheath being held stationary, so that the needle may be withdrawn rearwardly into the needle protector sheath. The slots preferably extend through one end of the body at the slot end nearest the bottom aperture. As the main aspect of the invention disclosed herein, an elongated anchor member extends forwardly from the body to be manually pressed to retain the protector sheath as the needle is being withdrawn from the skin of a patient, as broadly disclosed in the cited U.S. Patent No. 5,112,311. By this invention, the anchor member has an outer end portion that bends away from the patient in position of use, typically as a curved shape rather like the tip of a ski. Thus, when the sheath of this invention is being advanced toward a position to receive the needle when the needle is to be withdrawn from the patient, the anchor member more easily slides over adjacent bandages and the like. Preferably, the anchor also comprises a substantially flat, sheath-like extension of the top wall. Also, the anchor may join in the top wall at a junction line which is defined by a line of bending weakness, to facilitate Its downward bending when manually pressed. The body of the protector sheath, which may be rectangular in cross-section, is preferably tapered by about 0.2 to 5 degrees to define a forward end of the body that is of less cross-sectional dimension than a rear end of the body. This small amount of tapering or "draft" facilitates the molding of the sheath. It is also a preferred embodiment for the slots to extend through a forward end of the body with the slots each defining upper and lower surfaces. Forward end portions of the lower slot surfaces extend at an acute angle to the longitudinal axis of the body, to intersect the forward body end at a position that is substantially maximally spaced from the top wall. In those circumstances where a bottom wall is present, the lower slot surfaces preferably merge with the inner surface of a forward end portion of the bottom wall, to achieve such maximal spacing. The forward end portions of the upper slot surfaces may diverge from the lower slot surfaces and extend toward the top wall. Thus, wide slot portions are provided in each sidewall at the forward body end, which slot portions taper inwardly to communicate with the remainder of the slots, which remaining portions are substantially narrower. Thus, it becomes easy to advance the sliding sheath so that the front end thereof engages and captures the projecting wings of a needle hub, with the wings projecting outwardly through the slots. Preferably, a major portion of each of the slots defines an acute angle to the longitudinal axis. Also, most of the length of the slots may be straight. Thus, needle protector sheaths are provided which exhibit significant improvements in structure and functioning over those of the prior art. The terms "top", "bottom", and "side" as used herein are relative and exemplary in intent, and are not intended to exclude the use of a protector sheath of this invention in a different or varying position of spatial orientation. DESCRIPTION OF THE DRAWINGS Referring to the drawings, Fig. 1 is a perspective view of an embodiment of the sheath of this invention; Fig. 2 is a top plan view of the sheath of Fig. 1; Fig. 3 is an elevational view of the sheath of Fig. 1; Fig. 4 is a transverse sectional view taken along line 16-16 of Fig. 3; Fig. 5 is a longitudinal sectional view taken along line 17-17 of Fig. 2; and Fig. 6 is an enlarged, transverse sectional view taken along line 18-18 of Fig. 3. DESCRIPTION OF SPECIFIC EMBODIMENTS Referring to Fig. 1 through 6, a needle protector sheath 60 is disclosed, being generally similar in structure and function to the needle sheaths shown in US-A-5112311 except as otherwise described herein. Referring to Figs. 1 through 6, sliding needle protector sheath 60 is shown as a single molded piece comprising a body 62 having a top wall 64, a pair of sidewalls 66, a bottom wall 67, and open ends as shown in Figs. 4 and 6. Body 62 is shown to be of rectangular shape, defining an inner bore 69 for receiving a winged medical needle. A slot 70 is defined in each of sidewalls 66, with each slot being of substantially identical shape and positioning to the other slot in the other sidewall 66. It can be seen that each slot 70 is open to the forward end 68 of body 62 particularly, intersecting the forward end 68. Each slot 70 defines upper and lower surfaces 72, 74. Most of the pair of lower slot surfaces 74 of the respective slots 70 are shown to extend straight and at an acute angle to longitudinal axis 76 of body 62, to encounter the forward body end 68 at a position that is substantially maximally spaced from top wall 64; i.e., the distance between bottom wall 67 and lower slot surface 74 at end 68 is preferably a substantial practical minimum in light of the particular engineering and economic considerations for manufacture of the specific sheath 60. Typically, the spacing between surface 74 and the bottom surface of bottom wall 67 will be no more than about 3 millimeters at end 68, preferably no more than about 1 millimeter. The forward end portion of the upper slot surfaces 72 of the respective slots 70 can be seen to diverge from the forwardly positioned lower slot surfaces 74, to define a pair of wide slot portions 76 at forward body end 68. The respective portions 76 of slots 70 taper inwardly as the slot portions extend rearwardly from forward end 68, to communicate with the remaining portions 78 of slots 70. It can be seen that remaining portions 78 of slots 70 comprise the major portions of the respective slots 70, and in this embodiment are substantially straight along most of their length. A wing-catching slot recess 80 receives and retains the respective needle wings when protector sheath 60 is advanced into needle-enclosing position. Slot recess 80 may be shaped to receive the desired needle wings, and to effectively permanently hold them in retained relation so that the sheath is locked in place around the needle in a manner similar to that of the prior art. Thus, as sheath 60 is advanced along a set tube to effectively "swallow" a winged needle which is emplaced in a patient, the forward end 68 of bottom wall 67 can easily slide underneath the emplaced needle hub without causing the patient pain. At the same time, the wide, tapered slot portion 76 effectively facilitates the capture of the wings, to guide them to the straight portion 78 of each slot 70 as sheath 60 is advanced. The major portion of slot 70 occupies an acute angle to axis 76 to approximate the orientation of the needle in the patient, so that the needle is not bent or twisted as sheath 60 is advanced. Anchor member 82 is carried as an extension of top wall 64, extending forwardly of sheath body 62, as shown, and used as described in Patent No. 5,112,311. In this embodiment anchor 82 comprises a flat, substantially sheetllke extension of top wall 64, separated therefrom by a junction line 86 which defines a line of bending weakness, produced by the presence of a transverse groove extending partway through the plastic wall to create a hinge effect. Also, anchor member 82 defines an outer end portion 88 which bends away from the patient in position of use, bending also away from bottom wall 67, as shown in Fig. 3. Thus, anchor 82 is rather of the shape of the front end of a ski, with curved end 88 functioning in the manner of a ski to pass over bandages of varying thickness and the like as the sheath 60 is advanced toward the needle while emplaced in the patient. Projections 89 facilitate manual retention while the anchor is being pressed against the patient and the needle being withdrawn. Junction line 86 facilitates the downward bending of anchor member 82 as it is pressed against the patient. Thus, one may manually and easily press anchor 82 against the patient's skin and intervening bandages to retain protector sheath 60 as the needle is being withdrawn from the skin of the patient. The wings of the needle hub are captured by and move rearwardly along slots 78 until they enter slot portions 80, where they are locked in place. In this position, the needle is enclosed within the body 62 of the sheath, safely away from the risk of inflicting harm. The rectangular cross-section of this embodiment permits the needle sheath to stand up easily on a surface, while at the same time the needle is completely enclosed within sides of the body 62 after the sheath has been advanced around the needle. The above has been offered for illustrative purposes only, and is not Intended to limit the scope of the invention of this application, which is as defined in the claims below.

Claims: A medical needle protector sheath for a winged needle which comprises a body (62) having a top wall, sidewalls, and at least partially open ends; a slot (70) formed in each sidewall to receive a needle hub wing extending through each of said slots; and an elongated anchor member (82) extending forwardly from said body to be manually pressed against the patient's skin to retain said protector sheath as a needle is being withdrawn from the skin of the patient, characterized in that said anchor member (82) has an outer end portion (88) that is originally in bent shape such that it is bent outwardly from said body (62) in a direction bending away from the patient when the protector sheath is placed on the patient in position of use. The protector sheath of claim 1 in which said outer end portion (88) bends away in a curved shape. The protector sheath of the previous claims in which said body (62) is of rectangular cross section. The protector sheath of the previous claims in which said anchor member (82) comprises a substantially flat, sheetlike extension of the top wall (64), the outer end portion of said flat, sheetlike extension (82) being bent outwardly away from the patient in position of use. The protector sheath of the previous claims in which said anchor member (82) joins said top wall at a junction line which is defined by line (86) of bending weakness (86). The protector sheath of the previous claims in which said body (62) is tapered by about 0.2 to 5 degrees to define a forward end of said body that is of less crosssectional dimension than a rear end of said body. The protector sheath of the previous claims having a longitudinal axis (76) and in which said slots (70) extend through a forward end of said body, said slots each defining upper and lower surfaces (72,74), forward end portions (74) of the lower slot surfaces extending at an acute angle to the longitudinal axis to intersect said forward body end at a position that is substantially maximally spaced from said top wall (64), and forward end portions of said upper slot surfaces (72) diverging from the lower slot surfaces toward said top wall (64) to define wide slot portions at said forward body end that taper inwardly toward each other and communicate with the remainder of said slots (70). The protector sheath of the previous claims in which a major portion of each of said slots (70) defines an acute angle to said longituninal axis. The protector sheath of the previous claims in which a major portion of each of said slots (70) is straight. The protector sheath of the previous claims which carries a bottom wall (67) connected to the sidewalls, the forward end portion of the lower slot surfaces (74) merging with the inner surface of said bottom wall adjacent to the forward end of said body (62). The protector sheath of the previous claims in which said anchor member (82) in form of an elongated, substantially flat, sheetlike anchor member (82) extends forwardly from said body (62) to be manually pressed to retain said protector sheath as the needle is being withdrawn from the skin of a patient, said anchor joining said top wall (64) at a junction line (86) which is defined by a line of bending weakness.

Inventors: UTTERBERG DAVID S, UTTERBERG, DAVID S.
Applicants: DSU MED CORP, DSU MEDICAL CORPORATION
Application year: 1995
Main classification: A61M25
IPC codes: A61M5, A61M25