Apparatus for subcutaneous introduction of a needle

Abstract: Apparatus for subcutaneous introduction of a needle (2) in a living being. This needle (2) has to be placed substantially tangentially to the skin of said living being immediately under the skin during all of the needle introduction movement. Guiding means (4,5) are provided to guarantee the position of the needle (2) parallel to the skin. This guiding means (4,5) comprise two guiding members at both sides of the needle. The guiding members extend substantially parallel to the needle (2) and the point of external contact with the skin is at least level with the upper part of the needle. This means that the skin is folded between the guiding members and the needle.

Description: The invention relates to an apparatus according to the preamble of claim 1. Such an apparatus is known from US-A-3,324,854. In that specification a syringe needle is described for intravaneous introduction. Resilient guiding members are provided connected to each other at their free extremity which function to keep the part of the skin clamped between them to promote introduction of the needle. The needle is displaceable with regard to the guiding members. The invention aims to provide an apparatus for subcutaneous introducing of articles such as transponders. Such an apparatus is known from NL-A-9100160 (Texas Instruments Holland B.V.) In that application the use of a guiding rod is described extending in the same direction as the needle. This guiding rod is spaced from the needle with a distance corresponding to the thickness of the skin. In the position of use the guiding rod is above the needle and the skin is in the clearance between the needle and the guiding rod. Such an apparatus is especially realized for introduction in parts of an animal which are extremely rounded. As example the head of an animal is shown and the needle is introduced in the transfer face between the horizontal and vertical parts of the head near the ear. However, such a device will not function if the needle has to be introduced in a relatively flat portion of a living being. Needles are inserted for introduction of all kinds of fluids, such as drugs, as well as solid products. The solid products can comprise drugs and transponders for identifying the related animal. Often it is important that there is a guarantee that the needle slides between the skin and the bone cartilage or tissue being immediately under the skin. On the one hand damage to the bone has to be prevented and on the other hand exiting of the needle through the skin with its tip will result in a failure of introduction of whatever product which has to be introduced. The invention aims to overcome this problem and to provide an apparatus as above which is suitable to introduce a needle below the skin in a relatively flat portion of an animal. According to the invention this is realized with the characterizing features of the main claim. Through the use of rigid guiding members which are fixed relative to the needle positive introduction of the needle is provided. To be able to introduce the needle its extremity has to extend beyond the curved end portion of the guiding members. Through the use of two spaced guiding members between which the needle is positioned optimum guidance of the needle during introduction can be guaranteed. The externally acting lower surface of the guiding members should be at least at the same level of the lower surface of the needle which has to be introduced. This means that depending from the thickness of the skin of the related animal its skin is somewhat curved around the needle. In this way loosening of the skin from the tissue below is promoted. If the skin of the animal is not very thick or introduction of the related product has to be nearer to the skin of the animal the lower face of the guiding members contacting the skin of the animal has to be at least level top surface of the needle, i.e. the curvature of the skin between the guiding members and the needle is more considerable. Of course it is possible to further rise the position of the needle with regard to the guiding members to further flex the skin around the guiding members and needle. According to the invention each guiding member comprises a curved bar, wherein the apex of the curvature is provided for engagement with the skin during introduction of the needle parallel to the skin. The bar is curved such that its free extremity extends obliquely away from the axis of the needle beyond the tip of the needle. In this way it is possible to start introduction of the needle obliquely with regard to the skin for piercing of this skin. After that following the bar turns the apparatus downwardly to the skin of the animal through the curved part of the bar such that the needle can be further introduced through a smooth introduction movement where it is guaranteed that the needle will always be parallel to the skin of the animal, whatever curve the skin surface follows. The needle may be displaceable with regard to the guiding members. This can be realized in several ways but one of them is to prevent the needle extending from the housing in the condition of non use. According to a further embodiment of the invention the needle is a hollow needle and means are provided to transfer products therethrough. Transport of such products can more particularly be effected when the transfer means and guiding means are interconnected. This means that after introduction of the needle in the desired position below the skin of the animal through operation of the apparatus the guiding means and the transfer means remain stationary whilst the needle is retracted. The product cannot move along with the needle because of the presence of the transfer means and will be placed on the desired location. For ease of introduction the tip of the needle is preferably bevelled. This is realized such that the farthest extremity of such a tip will be remote from the skin during introduction movement under the skin after the needle has been introduced.. The invention will be further elucidated referring to a preferred embodiment of the invention shown in the drawing, wherein: Fig. 1 shows (partially in cross section) an apparatus according to the invention; Fig. 2 shows in elevation the front part of the apparatus according to Fig. 1; Fig. 3 shows in plan view the front part of the apparatus according to Fig. 1; Fig. 4 shows the use of the apparatus according to Fig. 1 during introduction in the head of an animal and fig. 5 a cross section according to line V-V in Fig. 4. In Fig. 1 an injector 1 is shown comprising a housing 3 and needle 2. The needle 2 is rigidly connected to housing 3 through sleeve 19. Between sleeve 19 and outer part of housing 3 sleeve 10 is provided to which guiding members 4 and 5 (see also fig.3) are connected. The outer part of housing 3 is provided with a trigger 12 which can be actuated against a spring 13. Trigger 12 is designed to engage an opening 11 in sleeve 10. Sleeve 10 is provided with a support block 9 in which a pushing rod 7 is mounted. One side of pushing rod 7 is introduced in hollow needle 2 whilst a protruding end of it acts to receive a compression spring 8 which on the other hand engages on housing 3. Guiding member 4 extends from its attachment point to sleeve 10 first substantially parallel to the needle, then curves downwardly below the needle and after that upwardly well above the needle to end in extremity 18. Extremity 18 is somewhat beyond bevelled tip 6 of the needle. 14 indicates a product to be introduced in an animal such as a drug or a transponder used for identifying animals. The apparatus shown in fig. 1 functions as follows. In the position shown in fig. 1 spring 8 is under compression. In this condition shown the needle is introduced under the skin of the animal as will be further elucidated with regard to fig. 4 and 5. After complete introduction of the needle and still in the position of fig. 1 trigger 12 is actuated. Because of force of spring 8 acting on support block 9 and releasing of sleeve 10 through trigger 12 sleeve 10 moves outwardly relative to housing 3. During this movement both guiding members 4 and 5 and pushing rod 7 will move outwardly. However, in practice this means that guiding members 4 and 5 and transfer rod 7 will remain stationary whilst needle 2 and housing 3 will retract from the animal. In the end position not shown the needle will be completely received in sleeve 10 so that there is no danger from the tip 6 of the needle. During this retracting movement product 14 will remain in position under the skin of the animal and will be placed after removing apparatus 1 from the animal. In fig. 4 and 5 the introduction of the injector 1 according to the invention is shown. To be able to pierce the skin of the animal injector 1 is introduced obliquely to the skin of the animal. This is facilitated by the shape of extremity 18 of guiding members 4 and 5. After piercing the skin through bevelled part 6 of the needle the injector is tilted downwardly to the skin of the animal. This tilting movement is guided by the curved shape of guiding members 4 and 5. After that the injector is displaced parallel to the skin of the animal. The skin is folded between the guiding members 4 and 5 pushing the skin downwardly in fig. 4 and the needle 2 trying to move the skin upwardly. This is shown more clearly in fig. 5. In this way the skin is also released from tissue below the skin and bone, cartilage or tissue being below the skin. The distance between the contact surface of the curved guiding members 4 and 5 and the upper surface of the needle engaging to the lower (inner) part of the skin can be varied according to the use of the needle. In fig. 2 an embodiment is shown wherein the needle is relatively "high" with regard to the contact face of the guided member. For example distance "a" can be several millimetres. However, as indicated above it is also possible that the contact surface of the guiding member is somewhat higher. Although the invention is described above relating to a preferred embodiment of the invention it is possible to realize all kinds of changes without leaving the scope of the appended claims.

Claims: Apparatus (1) for subcutaneous injection of a needle (2) in a living being, substantially tangentially to the skin of said living being, said apparatus comprising a housing (3), a needle (2) extending from said housing and two guiding means (4,5) having a portion substantially parallel to the needle and a curved end portion for determining the position of the needle relative to the living being extending substantially in the same longitudinal direction as the needle and arranged in use to outwardly engage the skin with a lower face, wherein the skin is positioned between the two guiding members, the guiding members and needle being positioned such relative to each other that in the position of introduction of the needle the lower face of each guiding member near the tip of the needle is at least at the same level of or lower than the lower part of the tip of the needle, characterised in that each guiding member (4,5) comprises a bar or rod having a free end (18) and in that the free ends (18) of the curved bars or rods extend obliquely away from the axis of the needle (2), the tip (6) of the needle (2) extending along the direction of the axis beyond the distal curved portion of the free ends of the bars or rods. Apparatus according to claim 1, wherein the needle is a hollow needle and means (7) are provided to transfer products (14) through said needle. Apparatus according to claim one of the preceding claims, wherein the guiding members and needle are positioned such relative to each other that in the position of use the face of each guiding member which in use is in contact with the skin is at least at the same level of the part of the needle which in use is remote from the skin. Apparatus according to one of the preceding claims, wherein the guiding member comprises a curved bar, the apex of the curvature being provided for engagement with the skin during introduction of the needle to maintain it parallel to the skin. Apparatus according to one of the previous claims, wherein the needle is displaceable with regard to the guiding members. Apparatus according to claim 6 or 7, wherein the transfer means and guiding means are interconnected. Apparatus according to one of the previous claims, wherein the tip of the needle is bevelled, in such a way that the farthest extremity of the tip is positioned remote from the skin of the living being after introduction of the needle under the skin.

Inventors: VAN DER AA BARTHOLOMEUS WILHEL, VAN DER AA, BARTHOLOMEUS WILHELMUS JOHANNES
Applicants: TEXAS INSTRUMENTS HOLLAND, TEXAS INSTRUMENTS INC, TEXAS INSTRUMENTS HOLLAND B.V., TEXAS INSTRUMENTS INCORPORATED
Application year: 1992
Main classification: A61M5
IPC codes: A61D7, A61B17, A61M5