BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention will now be explained in more detail with reference to the description of the Figures, in which:
FIG. 1 shows a conventional catheter;
FIG. 2 shows a conventional anchoring needle;
FIG. 3 shows an embodiment of the apparatus according to the invention;
FIG. 4 shows an alternative embodiment of the apparatus according to the invention; and
FIG. 5 shows a side elevational view of the apparatus in use.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a conventional catheter 1. The catheter 1 contains a conventional catheter needle 2 which is fed through the catheter 1. The needle 2 can be inserted into the tissue with catheter 1. After providing the needle 2 in the tissue, the needle 2 is removed from the catheter 1 by, for instance, withdrawing it at the back side, and the catheter 1 can be connected to a brachytherapy apparatus (not shown). The brachytherapy apparatus feeds a radioactive source through the catheter 1 to the position to be irradiated in the tissue. Conventional brachytherapy provides the placement of a number of catheters in a tissue to be irradiated in predetermined positions such that the tissue receives a predetermined irradiation dose from radioactive sources which are provided in the catheters.
FIG. 2 shows a conventional anchoring needle 3 which can be used for fixation in a tissue. Such anchoring needles known per se typically have an anchoring mechanism for anchoring in the tissue. Typically, such needles include a double wall of which the outer wall has multiple parallel indentations all round so that, upon pulling an inner catheter, the outer wall bends outwards at the location of the indentations so that the catheter locks in the tissue. The anchoring needle 3 typically comprises a fixing part 4 and a laterally movable anchoring element 5 to be anchored in the body part. The laterally movable anchoring element 5 can be fixed by rotation or displacement of the fixing part. This may, for instance, be achieved by means of a central part 6, which can be moved in a tube part 7 and which presses the anchoring element 5, formed by a strip-shaped structure provided in the tube part, laterally outwards upon displacement. FIG. 2 shows the position pressed outwards of the anchoring element 5.
FIG. 3 shows the catheter needle 8 and 9, respectively, according to the invention. In particular, the detailed view 10 shows end 11 of catheter needle 8 with anchoring and of catheter needle 9 without anchoring. End 11 is formed by a closed end 12 of a hollow guide tube 13. The tube material is a plastic. In the closed end 12, a sharp point 14 is placed. The sharp point 14 is made, for example, from a metal or ceramic material. As an example, titanium metal is used for the sharp point 14. Plastic points 14 have the property that they do not have the same sharpness as metal or ceramic points. The invention solves this problem by placing a sharp point 14 from a hard material in the plastic end 12 of the catheter tube 8 and 9, respectively. Thus, the catheter tube 8 and 9, respectively, has the same sharpness as a completely metal needle. Thus, the catheter tube 8 and 9, respectively, can puncture the skin directly, without pre-puncturing or other aids, and can be inserted into tissues difficult to penetrate for plastic needles, such as a prostate gland.
FIG. 4 shows a further embodiment according to the invention. Although the embodiment is shown as a locking needle 15 with an anchoring element 5 folding outwards, the principle according to the invention can of course also be applied to non-locking variants. FIG. 4 shows an inner tube 6 and an outer tube 7 movable around it, which are glued together near end 16 around which a sleeve-shaped element 17 is cased as a connecting element, which tapers on the front side, i.e. the side facing away from the catheter needle, into a sharp point 14. The sleeve-shaped element 17 is designed with a sharp needle and made of, for example, titanium. Other suitable materials may of course be used as well. Another variant may be a separate (sleeve-shaped) casing element or connecting element, which forms a connection between a (separate) point and the end of the catheter needle.
FIG. 5 shows a schematic view of the catheter needle in use. The catheter needle 1 may be anchored to a template 18. The template 18 serves to aid positioning the catheter needles 1 and 3. Some catheter needles 3 may involve the embodiment 3 with anchoring element 5 discussed with reference to FIG. 2. Both catheter needles 1 and 3 may be suitable for use as a guide tube for guiding a radioactive source (not shown).
The invention is not limited to the embodiments shown in the drawing, but may also comprise alternatives or variants thereof which fall within the scope of the following claims. Such variants are understood to fall within the claims defined as follows.
Patent Application
20070265486
