DE20121490U1 - Tool used as an operating instrument for investigating humans and animals comprises a working section consisting partially of ceramic and/or metallic base material covered by a barrier layer made from silicon dioxide - Google Patents

Abstract

Tool comprises a working section (2) consisting partially of ceramic and/or metallic base material covered by a barrier layer made from silicon dioxide. An independent claim is also included for an implant made partially from ceramic and/or metallic base material covered by a barrier layer made from silicon dioxide. Preferred Features: The base material is made from a ceramic, metal, metal alloy and/or metal compound, especially aluminum, aluminum compound, aluminum alloy and/or their mixtures. The barrier layer is impermeable for the base material, ions formed from it and/or bodily fluids.

Description

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Surgical tool and implant

The present invention relates to a surgical tool according to the preamble of claim 1 and to an implant according to the preamble of claim 8.

The term "surgical tool" is primarily understood to mean a device or instrument that is used during an operation and/or examination, particularly on the human or animal body, i.e. in particular is inserted and/or used, for example, to influence body tissue. In a broader sense, however, this also includes other instruments, devices and aids that are used during operations and/or examinations and in particular come into contact with the respective body.

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The term "working section" is understood here to mean at least a part of the surgical tool that is essential for the intended function of the surgical tool and/or is primarily in contact with or penetrates the body to be operated on and/or examined. In particular, this is a relatively small part in the area of the respective surgical or examination site. The surgical tool can therefore, for example, have further sections or parts, such as a handle or the like, that also come into contact with or penetrate the body.

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The term "implant" is understood here in the narrower sense to mean an element that can be inserted into the body of an animal or a human at least temporarily and that can, for example, perform therapeutic, support and/or joint functions, such as temporary implants, for example so-called "seeds", or stents for tumor treatment or therapy, tracheal stents, etc. In the broader sense, however, this also includes elements or the like that can be brought into contact with the body from the outside and/or in particular temporarily.

Implants in the form of stents are used, for example, to support dilated vessels. These tubular inserts are inserted after dilating narrowed vessels and then expanded radially so that the stents support the vessel walls on the inside.

Biocompatibility, i.e. compatibility with the body, is very important for surgical instruments and implants. Many materials used to date for surgical instruments and implants are increasingly suspected of causing undesirable side effects in the body, particularly due to the dissolution of components of the materials in the body.

Coatings on implants to protect them and increase biocompatibility (tolerance to the body) are generally known. However, the requirements for a protective layer or barrier layer are very high.

The barrier layer should be available at a reasonable price. The barrier layer should adhere well or at least sufficiently well to virtually any substrate or base material. Depending on the application, the barrier layer should be sufficiently flexible so that it does not come off when an implant is deformed, for example when a stent is expanded. The barrier layer should be sufficiently impermeable. The barrier layer itself should be very biocompatible (compatible with the body) and should not release any or at least no undesirable components into the body.

The present invention is based on the object of specifying a surgical tool and an implant which have a barrier layer which has a high biocompatibility with high impermeability, in particular which at least largely meets the above-mentioned requirements.

The above object is achieved by a surgical tool according to claim 1 or an implant according to claim 8. Advantageous further developments are the subject of the subclaims.

An essential idea of the present invention is that the barrier layer consists of silicon dioxide. This solution, which at first glance seems simple, allows the use of virtually any base material, since

Silicon dioxide can be deposited very durably on virtually any base material, especially by plasma coating.

Silicon dioxide has so far been used primarily for coatings on eyeglass lenses and food packaging. The proposed use in the medical field leads to various advantages.

Silicon dioxide is the most common inorganic compound in our environment. Accordingly, silicon dioxide is highly biocompatible, meaning it is compatible with the body.

Silicon dioxide has a very simple chemical structure, namely silicon and oxygen. Accordingly, no undesirable or risky dissolving processes in the body are to be expected.

Silicon dioxide can be deposited in very thin, amorphous layers. This allows sufficient flexibility to be achieved for every application, which means that unwanted detachment, for example when expanding a stent, can be ruled out.

Silicon dioxide forms a very dense, highly impermeable barrier layer, especially when plasma coated.

Further properties, features, aspects and advantages of the present invention are explained in more detail below for two embodiments with reference to the drawing. It shows

Fig. 1 is a schematic representation of a proposed opera

tion tool;

Fig. 2 a schematic representation of a proposed implant

tats in the form of a stent; and

Fig. 3 a partial representation of the schematic structure

of the surgical tool or the implant.

Fig. 1 shows a proposed surgical tool 1 in the sense explained at the beginning. The example shown is a forceps-like instrument or tool. As already explained, however, this can be any type of instrument, technical aid or tool for examinations and/or operations on the human or animal body.

The surgical tool 1 preferably has at least one working section 2, here two working sections 2. The working sections 2 form pincer-like gripping, holding and/or cutting elements. However, the term "working section" is not limited to a single part, but rather it can also refer to a plurality of parts on the one hand or to a section or region of a one-piece part on the other.

As already explained, the working section 2 is in particular the front or relevant area of the surgical tool 1, which comes into contact with the body (not shown) during an operation or examination.

Fig. 2 shows a perspective view of a proposed implant 3 in the form of a stent, which has been greatly simplified for illustrative purposes. In the example shown, the implant 3 forms a grid-like, tubular body. For alternative forms, functions and applications of the implant 3, please refer to the definition at the beginning.

Fig. 3 shows an enlarged section of the proposed material structure in a representation that is not to scale. This material structure is intended at least for the working sections 2 of the surgical tool 1 or, if necessary, for the entire surgical tool 1. This material structure is also intended for the proposed implant 3. For the sake of simplicity, reference is made below only to the implant 3, even if the corresponding statements apply to at least one working section 2 of the surgical tool 1, several working sections 2 of the surgical tool 1 or the entire surgical tool 1.

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The implant 3 consists at least essentially of a base material 4 indicated in Fig. 3. In particular, Fig. 3 shows only a partial section into the material of the implant 3.

The base material 4 can basically be any material or any material with suitable properties, whereby biocompatibility (body compatibility) is not important. If necessary, it can also be a composite material.

The base material 4 is covered by a barrier layer 5 made of a semi-metal oxide, namely silicon dioxide, on its surface, at least in surface areas 6 that are free and/or accessible to body fluids or tissue, and is protected in particular from body fluids and other endogenous substances. The barrier layer 5 is designed to be particularly impermeable to the base material 4, ions formed therefrom and/or body fluids or other endogenous substances. In this way, an unwanted dissolution of the base material 4 in the body can be prevented.

In the example shown, the base material 4 preferably consists at least essentially of aluminum, an aluminum compound, an aluminum compound and/or a mixture thereof. In particular of relatively pure aluminum. The base material preferably consists of at least 95% by mass, preferably 97 or 98% by mass, of aluminum, in particular of a corresponding aluminum alloy.

When operating, examining and/or implanting, a determination of the position and/or function of the surgical instrument and/or the implant based on magnetic resonance is increasingly used - especially with a view to making interventions as minimally invasive as possible, i.e. microinvasive - for which a so-called magnetic resonance tomograph is used, for example. Magnetic resonance - referred to here as MR for short - is therefore used here in particular to depict spatial relationships in a body, for example the position of tissues, organs, surgical instruments and/or implants, whereby a relatively strong magnetic

field and substances and materials can be distinguished due to their different magnetic properties.

In order to be able to use MR, it is necessary to use MR-compatible materials for surgical tools or their working sections and for implants. When using a conventional material such as stainless steel, such artifacts (misrepresentations) arise that MR does not allow for any or only insufficient (image or spatial) resolution. The use of aluminum as the base material 4 surprisingly results in a particularly MR-compatible implant 3. Tests have shown that aluminum is surprisingly not visible or virtually invisible in an MRI scanner. When using MR, the artifacts that are otherwise generally present with metals do not occur.

The intended barrier layer 5 is preferably relatively thin and preferably amorphous. This results in good or sufficient flexibility. This is particularly important when the implant 3 is designed as a stent in order to avoid detachment of the barrier layer 5 during the radial expansion of the stent inside a vessel, as is usually the case.

Preferably, the barrier layer 5 is at least substantially uniformly thick. In particular, the average thickness is 10 to 200 nm, preferably 20 to 100 nm and in particular approximately 50 nm.

The base material 4 is preferably plasma-coated to form the barrier layer 5, i.e. the barrier layer 5 is applied by a plasma process. The material to be applied, here in particular non-oxidized silicon, is evaporated in a vacuum, for example, and reacts with the addition of oxygen on the surface of the implant 3 to form a firmly adhering oxide layer that is predominantly amorphous and thus flexible.

By way of example, for the possibilities of coating, in particular the application of a silicon dioxide layer, reference is made to US 4,917,786, US 5,096,558, US 5,565,248 and US 5,662,741, the contents of which are hereby incorporated by reference.

is mentioned as a supplementary disclosure. However, the application is not limited to pure plasma processes. Rather, other processes, in particular plasma-assisted processes, such as the plasma-assisted PVD process or the plasma-assisted CVD process, can also be used, as disclosed in the article "Character roles" by Volker Buck and Horst Ehrich, Essener Unikate, Material Wissenschaft, Volume 13, Universität GH Essen / Wissenschaftsverlag, ISSN 0944-6060, page 42 following. The aforementioned journal is mentioned in full as a supplementary disclosure with regard to coating processes and usable materials, including usable biocompatible materials.

According to the proposal, the barrier layer 5 consists at least essentially of silicon dioxide. Silicon dioxide, as the most common inorganic compound, has excellent biocompatibility, i.e. it is optimally tolerated by the body. Silicon dioxide can also be used to form a sufficiently dense or impermeable barrier layer 5.

The preferably provided amorphous formation also achieves sufficient flexibility and adhesion to the base material 4 or the surface areas 6 to be covered.

Claims (15)

1. Surgical tool ( 1 ), in particular for the human and/or animal body, with a working section ( 2 ) which consists at least partially of preferably ceramic and/or metallic base material ( 4 ) which is covered by a barrier layer ( 5 ), characterized in that the barrier layer ( 5 ) consists of silicon dioxide. 2. Surgical tool according to claim 1, characterized in that the entire working section ( 2 ), in particular the entire surgical tool ( 1 ), consists at least substantially of the base material ( 4 ). 3. Surgical tool according to claim 1 or 2, characterized in that the base material ( 4 ) consists of ceramic, metal, a metal alloy and/or a metal compound, in particular of aluminum, an aluminum compound, an aluminum alloy and/or mixtures thereof. 4. Surgical tool according to one of the preceding claims, characterized in that the barrier layer ( 5 ) is impermeable to the base material ( 4 ), ions formed thereby and/or body fluids. 5. Surgical tool according to one of the preceding claims, characterized in that the barrier layer ( 5 ) covers all free and/or surface areas ( 6 ) accessible to body fluids or tissue. 6. Surgical tool according to one of the preceding claims, characterized in that the barrier layer ( 5 ) is amorphous and/or has an average thickness of 10 to 200 nm, preferably 20 to 100 nm and in particular of about 50 nm. 7. Surgical tool according to one of the preceding claims, characterized in that the barrier layer ( 5 ) is formed by plasma coating. 8. Implant ( 3 ) at least partially made of preferably ceramic and/or metallic base material ( 4 ) which is covered by a barrier layer ( 5 ), characterized in that the barrier layer ( 4 ) consists of silicon dioxide. 9. Implant according to claim 8, characterized in that the entire implant ( 3 ) consists at least essentially of the base material ( 4 ). 10. Implant according to claim 8 or 9, characterized in that the base material ( 4 ) consists of ceramic, metal, a metal alloy and/or a metal compound, in particular of aluminum, an aluminum compound, an aluminum alloy and/or mixtures thereof. 11. Implant according to one of claims 8 to 10, characterized in that the barrier layer ( 5 ) is impermeable to the base material ( 4 ), ions formed thereby and/or body fluids. 12. Implant according to one of claims 8 to 11, characterized in that the barrier layer ( 5 ) covers all free and/or surface areas ( 6 ) accessible to body fluids or tissue. 13. Implant according to one of claims 8 to 12, characterized in that the barrier layer ( 5 ) is amorphous and/or has an average thickness of 10 to 200 nm, preferably 20 to 100 nm and in particular of about 50 nm. 14. Implant according to one of claims 8 to 13, characterized in that the barrier layer ( 5 ) is formed by plasma coating. 15. Implant according to one of claims 8 to 14, characterized in that the implant ( 3 ) is designed as a stent.