A SET OF DOUBLE NEEDLES FOR INJECTING LIQUID MEDICINE

Abstract: A set of double needles (1, 2) for injecting liquid medicine comprises an inner needle (1) and an outer needle (2) into which the inner needle (1) is inserted. The inner needle (1) is longer than the outer needle (2) and has a curved portion at the top thereof, so that the curved portion of the inner needle (1) protrudes from the outer needle (2) when the inner needle (1) is fully inserted into the outer needle (2). On the other hand, the curved portion of the inner needle (1) is straightened in the outer needle (2) when the inner needle (1) is retracted in the outer needle (2) so that the inner needle (1) can be rotated therein whereby the injecting point can be varied in a predetermined area in a single puncturing of the needles (1, 2).

Description: The invention relates to a set of double needles for injecting liquid medicine, comprising an inner needle and an outer needle into which said inner needle is inserted, wherein said inner and outer needle are fixed to bases respectively, and said base for said outer needle has a measuring mark for measuring a protruding length of said inner needle thereon. A device known in this field is described in the US-A-3 993 079 which relates to such a set of double needles. The set of needles described in this patent has the disadvantage that always the same part of the human body is punctured by the inner needle. In addition there are no means to spread the liquid medicine to different parts of a predetermined area by using only a single puncturing. Accordingly, it is an object of the invention to provide a set of double needles for injecting liquid medicine by which liquid medicine is injected into a plurality of affected parts in a single puncturing thereof in a predetermined area thereby to a avoid the increase of a pain for a patient by using different ways in which the inner needle is puncturing said affected parts. It is further desirable to provide a set of double needles by which an injecting point can be varied in a predetermined way. According to the object of this invention the inner needle is provided with a curved portion at its tip, said curved portion being straightened within said outer needle when retracted in a predetermined length L thereof, said base for said inner needle is provided with projections thereon, said base for said outer needle is provided with two grooves thereon into which said projections are engaged, and the size of the groove which is provided at the back side of said base for said outer needle is slightly greater than that of the groove which is provided at the front side of said base for said outer needle. It is advantageous that said base for said outer needle is transparent and has a standard mark for angle rotation of said base for said inner needle. Further it is recommended that each of said bases for said inner and outer needles comprises a square portion to allow the rotation of each by 90 degrees. The invention will be described in detail in accordance with the following drawings, wherein Fig.1 to 3 are cross-sectional views illustrating a relation between an inner and an outer needle according to the invention, Fig. 4 is an explanatory view showing a covering area of a single puncturing of a set of double needles according to the invention, Fig. 5A is a cross-sectional view illustrating a base fixing an outer needle thereto according to the invention, Fig. 5B is a perspective view illustrating a base fixing an inner needle thereto according to the invention, Fig. 6A is a perspective view illustrating a set of double needles for injecting liquid medicine in the preferred embodiment according to the invention, and Fig. 6B and 6C are cross-sectional views each illustrating a relation of bases for inner and outer needles in the preferred embodiment according to the invention. In Fig. 5A und 5B, the two parts of the set of double needles for injecting liquid medicine are shown. There are provided an inner needle 1 having a curved portion at the tip thereof and an outer needle 2 into which the inner needle 1 is inserted. The inner and outer needle 1 and 2 are provided with bevels 1a and 2a respectively and the inner needle 1 is longer than the outer needle 2 so that the curved portion of the inner needle 1 protrudes from the outer needle 2 as described later in more detail when the inner needle 1 is fully inserted into the outer needle 2. Further the inner and outer needles 1 and 2 are fixed to bases 3 and 4 respectively. The base 4 for the outer needle 2 is transparent in a prefered embodiment and comprises a main body 4a having a measuring mark thereon and an end portion having a standard mark thereon. On the other hand the base 3 for the inner needle 1 is provided with an angle mark 7 thereon. In operation the bevel 1a for the inner needle 1 is positioned at the distance r from the center line because the inner needle 1 has the curved portion at the top thereof when the needle 1 protrudes from the bevel 2a for the outer needle 2 in a predermined length L of, for instance 25 mm as shown in Fig. 1. The inner needle 1 is straightened in the outer needle 2 in accordance with the resilient deformation thereof when the bevel 1a of the inner needle 1 is retracted into the outer needle 2 as shown in Fig. 2. At this stage, the inner needle 1 is rotated by 180 degrees in accordance with the angle mark 7 on the base 3 and the standard mark on the end portion of the base 4. The bevel 1a positioned at the distance r in opposite direction from the center line due to the resilience thereof when the inner needle 1 protrudes from the bevels 2a for the outer needle 2 in a predetermined length L mentioned above as shown in Fig. 3. The protruding length L is adjusted by determining the front end portion 3a for the base 3 in accordance with the measuring mark. It is understood form the explanation as shown in Fig. 4 that liquid medicine is projected to cover a predetermined area 10 having a diameter 2r the center of which is indicated at the bevel 2a for the outer needle 2. In Fig. 5A and 5B there are shown the two parts of a set of double needle for injecting liquid medicine according to the invention with special reference to grooves in the base 4 of the outer needle 2 and projections 13 on the base 3 for the inner needle 1. The base 3 is provided with projections 13 thereon each of which is deformed resiliently, while the base 4 is provided with grooves 11 and 12 on the inner surface thereof. In Fig. 5A and 5B like reference numerals indicate like parts as in Fig. 6A. In operation the base 3 is positioned inside the base 4 such that the inner needle 1 is inserted into the outer needle 2. At this stage the projections 13 are engaged into the groove 12 and the base 3 is rotated by a predetermined angle in accordance with the standard mark on the end portion and the angle mark 7 on the base 3. At the next stage, the base 3 is pushed forward to the projections 13 are compressed, whereby the base 3 is moved in the slidable manner inside the base 4 and that the projections 13 are engaged into the groove 11 thereby the base 3 is stopped while the inner needle 1 protrudes from the bevel 2a of the outer needle 2 in a predetermined length L as mentioned before. The size of groove 12 is slightly greater than that of groove 11, such that the force of engaging the projections 13 into the groove 11 is slightly greater than that of engaging the projections 13 into the groove 12 so that the handling of the double needle becomes easier. In Fig. 6A to 6C, there is shown a set of double needles in another embodiment according to the invention wherein a base 4 for an outer needle 2 is of a square having an opening portion 14 at the side thereof, a slit 15 to be utilized as a standard mark for the rotation at the other side thereof and a mark 18 to be utilized as a standard point. On the other hand, the base 3 for the inner needle 1 comprises a square portion 3a and a circular portion 3b to which a syringe (not shown) is connected. A measuring mark 16 is provided on a square portion 3a and a standard mark 17 is provided on the circular portion 3b so that the corresponding relation between the inner and outer needles 1 and 2 is known in accordance with the relative positions of the mark 16 and 17 in regard to the slit 15 and mark 18. In operation, the base 3 is pulled back such that the top as thereof is positioned at the opening portion 14 thereby the base 3 is rotated as shown in Fig. 6B. In rotation of the base 3, the base 4 is deformable so that the base 3 can be easily stopped after the rotation of 90, 180 or 270 degrees. Thereafter the base 3 is pushed forward so that the inner needle 1 protrudes from the bevel 2a of the outer needle 2 in a predetermined length by checking the measurung mark 16 in regard to the mark 18.

Claims: A set of double needles for injecting liquid medicine, comprising an inner needle (1) and an outer needle (2) into which said inner needle (1) is inserted, wherein said inner and outer needles are fixed to bases (3, 4) respectively, and said base (4) for said outer needle (2) has a measuring mark for measuring a protruding length of said inner needle (1) thereon, characterized in that the inner needle (1) is provided with a curved portion at its tip, said curved portion being straightened within said outer needle (2) when retracted in a predetermined length L thereof, said base (3) for said inner needle (1) is provided with projections (13) thereon, said base (4) for said outer needle (2) is provided with two circumferential grooves (11, 12) thereon into which said projections (13) are engaged, and the size of the groove (12) which is provided at the back side of said base (4) for said outer needle (2) is slightly greater than that of the groove (11) Which is provided at the front side of said base (4) for said outer needle (2). A set of double needles for injecting liquid medicine according to claim 1, characterized in that said base (4) for said outer needle (2) is transparent and has a standard mark for angle rotation of said base (3) for said inner needle (1), and said base (3) for said inner needle (1) has an angle mark (7) for angle rotation of said base (3) for said inner needle (1). A set of double needles for injecting liquid medicine according to one of the preceding claims, characterized in that each of said bases (3, 4) for said inner (1) and outer (2) needles comprises a square portion to allow the rotation of each by 90 degrees.

Inventors: MARUYAMA MASARU C/O HAKKO ELECTRIC MACHINE, OHTO, MASAO, SEKINE, TETSUO, TAKAHASHI, HIROSHI, TANAKA, MASATAKA C/O HAKKO ELECTRIC MACHINE
Applicants: HAKKO ELECTRIC MACHINE WORKS CO. LTD.
Application year: 1986
Main classification: A61M5
IPC codes: A61M5