DE1021543B - Medical needle - Google Patents

Description

GERMAN

The invention relates to a needle for medical use Purposes. Such a needle is usually made of metal; needles made of plastic have also become known. The needle according to the invention consists partly of metal, parts of plastic.

In the case of an injection syringe, the proposal has already been made to remove the gas piston, which is inside the glass syringe barrel is slidable, to be coated with a layer of tetrafluoroethylene in order to in this way to prevent the piston from sticking to the cylinder wall. It had been recognized that such sticking comes about easily because of the processed by means of the syringe Liquids build up a layer on the piston and the cylinder wall, which leads to an enlargement between the piston and the cylinder wall, especially if the piston is careless is left in the cylinder even for a short time. Tetrafluoroethylene now prevents it as a result of its dissolving The effect is the formation of such an adhesive layer which hinders the movement of the piston.

In contrast, the present invention is concerned with the problem of sticking the needle in to facilitate the tissue of the human body and to ensure that this process is carried out for the patient is as painless as possible.

It was found that this problem can be solved in an ideal way if the puncture with the needle surfaces in contact with the tissue with a layer of polymerized halogenated i Ethylene, e.g. B. polytetrafluoroethylene or polymonochlorotrifluoroethylene, be coated. What can be attributed to the fact that a needle with such a The layer can be pierced more easily and, above all, more painlessly than the previously used ones Needles, is still unclear. In any case, this success is not based on that exploited according to the older invention Ability to dissolve a sticky mass; because this property can in the brevity of the Einistichzeit do not have any effect.

Since the needle coated with the new layer penetrates the tissue particularly easily, i.e. ¹ no longer needs to use as much force as before, there is no longer any risk of the needle bending or even breaking.

When using the coating according to the invention, the further advantage is achieved that the Needles no longer have to be produced from a smoothly ground and polished tube as before, but can also consist of raw drawn tube; because the coating itself forms the smooth surface, that comes into contact with the tissue.

Furthermore, the coating forms a protection against

Applicant:

S. & RJ Everett & Co., Ltd.,
Thornton Heath, Surrey (UK)

ίο Representative: Dipl.-Ing. K. Lengner, patent attorney,
Hamburg 1, Mönckebergstr. 7th

Claimed priority:
Great Britain April 15, 1954

Samuel James Everett,

Thornton Heath, Surrey (UK),

has been named as the inventor

Corrosion, SO 'that the needles are no longer stainless Steel need to be made.

Finally is to. notice that the polytetrafluoroethylene has an excellent anti-coagulation property; it is particularly beneficial in needles or syringes that are used to draw blood or the body to feed. Keeping such needles and syringes clean and clean is therefore considerably simplified, apart from the fact that the other coagulation-related dangers largely are eliminated.

The layer proposed according to the invention is expediently applied by spraying or brushing on or by dipping the needles into a dispersion of the polymerized halogenated ethylene; after the layer has been applied, it is sintered. Surgical needles are usually made of stainless steel. In order to prevent the layer from becoming detached from the steel, it may be necessary to apply an intermediate layer of the dispersion before the final layer is applied. So either the entire needle can be covered with the mentioned layer, or in the case of the injection needles only the bores are provided with the mentioned layer. In the case of needles which have gaps or similar changes on the surface, the layer needs, for example, only ¹ or the like arranged in the area of these gaps

709 846/18

to be in order to cover this and a smooth, even ' To create surface. In general, polytetrafluoroethylene has been used for the described Proven to be more suitable than polymonochlorotrifluoroethylene,

Further details and features of an expedient embodiment of the invention can be found in FIG Description of two exemplary embodiments illustrated in the drawing.

Fig. 1 shows a surgical needle in longitudinal section, and

Fig. 2 also shows an injection needle in longitudinal section.

The needle of Fig. 1 consists of a main body 1, which has a tip 2 and at its rear iS End has a flat concave annular groove 3; the extreme rear end of this needle body 4 is conical educated. The diameter of the edge 5 at which the conical end: 4 and the concave ring groove 3 merge into one another, is slightly smaller than the outer diameter of the needle body 1. For fastening · of the sewing thread is a sleeve 6 which fits tightly over the edge 5 and over the rear end the needle is pushed over until its front edge hits the shoulder 7, which of the concave groove is formed. In this way, the sleeve is securely held, the sewing thread can then inserted into the sleeve from behind; it is secured in it by crimping or the like.

The gap between the front end of the sleeve 6 and the cylindrical surface of the needle body 1 is a ring groove that is difficult to sterilize and which easily damaging the tissue, causing pain to the patient. Around the entire surface of the To lubricate the needle and also to fill this cavity and thus the needle body, which is not is polished to give a smooth surface the whole needle is covered with a layer of polytetrafluoroethylene. As already mentioned, this is the case the needle is dipped in a dispersion and the layer produced is then sintered. That way is first an intermediate layer is formed, onto which a second cover layer 9 is applied. To this In this way, a surface is created that has a very low coefficient of friction. The irregularity in the area of the groove between the sleeve 6 and the needle body 1 is largely compensated; also all other irregularities on the needle surface resulting from the manufacture balanced so that a smooth surface is created. In the case of the injection needle according to FIG. 2, the needle shaft 10 has a needle tip 11 and a fastening attachment 12 on; the bore of the needle is with a layer 13 and the outer surface with a layer made of polytetrafluoroethylene.

Claims (5)

Patent claims: 1. Needle made of metal and plastic for medical purposes, characterized in that that at least part of the needle surface with a layer of polymerized halogenated Ethylene, e.g. B. polytetrafluoroethylene or polymonochlorotrifluoroethylene, is covered. 2. Needle according to claim 1, characterized in that the unpolished outer needle surface with a layer according to claim 1 is covered. 3. Surgical A ^T similar needle according to claim 1 or 2, characterized in that the needle body has at its rear end a part of small diameter over which fits a sleeve holding the suture thread, wherein the cover layer extends over the point where the The surface of the needle body and the sleeve abut one another. 4. Injection needle according to claim 1, characterized in that that the needle bore is covered with a cover layer according to claim 1. 5. The method for producing a needle according to claim 1, characterized in that the Layer of polymerized, halogenated ethylene by repeated, preferably twice Immersing the needle in a dispersion of the polymerized, halogenated ethylene with each subsequent sintering is generated. Considered publications:
U.S. Patent No. 2,607,342. 1 sheet of drawings © 709 846/18 12.57