US-12618168-B2 - Method for surface treatment and/or production of a medical product, and a medical product

US12618168B2US 12618168 B2US12618168 B2US 12618168B2US-12618168-B2

Abstract

A medical product and a method of surface treatment and/or manufacture of the medical product. The method includes the step of electrochemically etching the medical product. The medical product can include a metal or alloy and have one or more of the following features: a pitting corrosion potential of 100 mV to 1200 mV, a contact angle of 90° to 140°, and a passive layer having a thickness of 1 nm to 10 nm that coats at least sections of the surface of the medical product.

Inventors

Andreas Gaßner
Lukas Waidelich

Assignees

AESCULAP AG

Dates

Publication Date: 20260505
Application Date: 20210401
Priority Date: 20200406

Claims (20)

1 . A method of surface treating and/or producing a precursor or a component of a surgical instrument, the precursor or the component of the surgical instrument comprising a metal or an alloy, the method comprising the steps of: slide finishing a surface of the precursor or the component of the surgical instrument; and electrochemically etching the precursor or the component of the surgical instrument at a voltage applied to an anode of 1.4 V to 1.7 V and/or at a current density of 1.6 A/dm 2 to 2.2 A/dm 2 , wherein the step of electrochemically etching the precursor or the component of the surgical instrument reduces reflection of light from the precursor or the component of the surgical instrument.
2 . The method according to claim 1 , wherein the step of electrochemically etching the precursor or the component of the surgical instrument is preceded by a grinding operation on the surface of the precursor or the component of the surgical instrument.
3 . The method according to claim 1 , wherein the surface of the precursor or the component of the surgical instrument is not treated with a blasting agent and/or is not electropolished to increase surface smoothness.
4 . The method according to claim 1 , wherein the step of electrochemically etching the precursor or the component of the surgical instrument is performed using an acidic aqueous electrolyte solution.
5 . The method according to claim 1 , wherein a surface of the precursor or the component of the surgical instrument is not treated with a passivating acid or a passivating acid-containing solution.
6 . The method according to claim 1 , wherein the step of electrochemically etching the precursor or the component of the surgical instrument is followed by the steps of: packing the precursor or the component of the surgical instrument; and sterilizing the precursor or the component of the surgical instrument.
7 . The method according to claim 6 , wherein the step of sterilizing the precursor or the component of the surgical instrument is performed prior to the step of packing the precursor or the component of the surgical instrument.
8 . The method according to claim 1 , wherein the precursor or the component of the surgical instrument comprises a stainless steel.
9 . The method according to claim 8 , wherein the stainless steel is a martensitic, corrosion-resistant stainless steel.
10 . The method according to claim 1 , wherein the step of electrochemically etching the precursor or the component of the surgical instrument is preceded by the step of: belt finishing on the surface of the precursor or the component of the surgical instrument.
11 . A method of surface treating and/or producing a precursor or a component of a surgical instrument, the precursor or the component of the surgical instrument comprising a metal or an alloy, the method comprising the steps of: slide finishing a surface of the precursor or the component of the surgical instrument; and electrochemically etching the precursor or the component of the surgical instrument at a voltage applied to an anode of 1.4 V to 1.7 V and/or at a current density of 1.6 A/dm 2 to 2.2 A/dm 2 , wherein the step of electrochemically etching the precursor or the component of the surgical instrument forms a roughened product surface that scatters incident light.
12 . A method of surface treating and/or producing a precursor or a component of a surgical instrument, the precursor or the component of the surgical instrument comprising a metal or an alloy, the method comprising the steps of: slide finishing a surface of the precursor or the component of the surgical instrument; and electrochemically etching the precursor or the component of the surgical instrument at a voltage applied to an anode of 1.4 V to 1.7 V and/or at a current density of 1.6 A/dm 2 to 2.2 A/dm 2 , wherein the step of electrochemically etching the precursor or the component of the surgical instrument forms a microstructure comprising open etching pits.
13 . The method according to claim 1 , wherein the step of slide finishing the surface of the precursor or the component of the surgical instrument comprises introducing the precursor or the component of the surgical instrument into a vessel together with slide finishing bodies.
14 . The method according to claim 13 , wherein the slide finishing bodies are contained in an aqueous solution.
15 . The method according to claim 14 , wherein the aqueous solution contains an additive selected from the group consisting of anticorrosives, degreasing agents, pickling agents, separating agents, and mixtures thereof.
16 . The method according to claim 13 , further the step of slide finishing the surface of the precursor or the component of the surgical instrument further comprises displacing the precursor or the component of the surgical instrument relative to the slide finishing bodies to cause abrasion of material.
17 . The method according to claim 13 , wherein the slide finishing bodies comprise material selected from the group consisting of ceramic, plastic, natural products, and steel.
18 . The method according to claim 13 , wherein the slide finishing bodies are free of corners and edges.
19 . The method according to claim 13 , wherein the slide finishing bodies comprise corners and edges.
20 . The method according to claim 1 , wherein the step of slide finishing the surface of the precursor or the component of the surgical instrument comprises barrel finishing, vibratory finishing, plunge finishing, drag finishing, centrifugal finishing or pressure flow lapping.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is the United States national stage entry of International Application No. PCT/EP2021/058723, filed Apr. 1, 2021, and claims priority to German Application No. 10 2020 204 431.7, filed Apr. 6, 2020. The contents of International Application No. PCT/EP2021/058723 and German Application No. 10 2020 204 431.7 are incorporated by reference herein in their entireties. FIELD The invention relates to a method of surface treatment or processing and/or manufacture of a medical product and to a medical product. BACKGROUND Medical products, such as surgical instruments in particular, are generally subjected to a surface treatment before they are complete. For this purpose, the surfaces of the products can be processed, for example, by means of slide finishing and/or belt finishing. This can eliminate defects in the parent material and/or forging-related defects, for example decarburized regions, or surface defects, for example pores, scars or cracks, which would otherwise have an adverse effect on the corrosion resistance of the products. However, belt finishing can give rise to fine notches or elevations on the product surface. These can be turned over or flattened in a subsequent treatment step. This can give rise to doubled-over material. Moreover, there can be isolated instances of material transfer, for example of silicon oxide particles, from an abrasive belt to the product surface. Such material transfer and the stress on the medical product associated with the mechanical processing can in turn generate or increase intrinsic stresses in the product. An additional problem is that surface defects in the product that have not been eliminated or generated in the grinding operation can be eliminated only to a limited degree in a downstream treatment step. Dulling of a medical product can be accomplished using spherical blasting agents, for example glass beads. This results in plastic deformation of the product surface, by means of which it is increased in size and roughened. Since glass beads are generally very hard (Mohs hardness of 6) and are brittle as well, some degree of breakage of the blasting agent will occur over time. As a result, both spherical glass beads and broken glass beads will hit the surface of the product during the dulling step. While broken glass beads will create sharp notches on the product surface, unbroken glass beads will leave spherical indentations on the surface of the product. As a result of the impact of broken and unbroken glass beads, there is an interaction between the product surface notched by the broken glass beads and the product surface smoothed by the unbroken glass beads. This can likewise result in doubled-over material. In addition to the plastic deformation and the associated generation of intrinsic stresses, material transfer of the blasting agent to the product surface can take place. This material transfer is particularly significant in the region of notches, in which accumulated glass bead material can remain. As an alternative to the blasting agent treatment described above using the example of glass beads, it is possible to brush the surfaces of medical products. For this purpose, the product surfaces may be processed with brushing disks, for example with the aid of a disk-shaped abrasive pad or of nylon fibers in a disk arrangement with abrasive particles. Aluminum oxide and/or silicon oxide particles have typically been applied to the brushing disks. A brushing step increases the corrosion resistance of the product surface by comparison with a dulled product surface, but a disadvantage is that brushed product surfaces have greater reflection characteristics than dulled product surfaces. It is also known that microstructures or notches formed by doubled-over material on a product surface and any associated generation or increase of intrinsic stresses in the product have an adverse effect on the corrosion resistance thereof. In the case of material transfer, for example during belt finishing and/or dulling, an additional factor is that the material transferred generates additional microstructures and can cause the weakening of a passivation layer. SUMMARY It is an object of the invention to provide a method of surface treatment or processing and/or manufacture of a medical product, which at least partly avoids disadvantages that occur in methods of the generic type and especially leads to a medical product having elevated corrosion resistance and reduced reflection characteristics. It is a further object of the invention to provide a corresponding medical product. In a first aspect, the invention relates to a method of surface treatment or processing and/or manufacture of a medical product, wherein the medical product comprises a metal or an alloy or consists of a metal or an alloy. The method comprises the following step: electrochemically etching the medical product or the surface of the medical product. The