Anchoring prongs for an implant with partially coated prong ends

Abstract

Anchoring prong arrangement (1) for a medical implant (100), in particular for an intracardiac pacemaker (100), comprising a plurality of anchoring prongs (2) which are preferably connected to an annular base (3) and preferably project from it, wherein each anchoring prong (2) has a base section (20), an intermediate section (21) adjoining the base section and a tip (22) adjoining the intermediate section for penetrating tissue, wherein the respective intermediate section (21) is coated with gold and wherein the respective tip (22) is free of gold, so that the respective tip (22) has a cross-section that is smaller than the cross-section of the intermediate section (21) adjoining the tip (22).

Description

[0001] The present invention relates to an anchoring tine arrangement, in particular an anchoring tine assembly, for a medical implant, especially an active medical implant such as an intracardiac pacemaker. Such devices are also referred to as iLPs (implantable leadless pacemakers) because they do not have external electrode leads, but rather the electrodes are arranged on the housing. The anchoring tines are also referred to as tines. The assembly in question is also commonly referred to as a tine array.

[0002] In the prior art, anchoring tines fully coated with gold, anchoring tines partially coated with gold, and anchoring tines without gold coating are known.

[0003] When coating such prongs with gold, there is a fundamental problem of thickening the anchoring prongs, which is noticeable in an increase in the cross-section of the anchoring prong tips.

[0004] Typically, the anchoring tines have a cross-section of approximately 120 µm * 700 µm = 0.084 mm². 2 (Material thickness x width). The gold plating has a thickness of approximately 20 µm all around. This means that at the tips of the anchor pins, the cross-section is 160 µm * 740 µm = 0.118 mm. 2 This corresponds to a cross-sectional increase of approximately 40%.

[0005] This results in the anchoring prongs having to be pressed into the tissue with approximately 40% greater force, which can potentially lead to the anchoring prongs buckling and make proper fixation in the tissue no longer possible. Based on this, the present invention aims to provide an anchoring prong arrangement that allows for gold plating of the anchoring prongs without the aforementioned disadvantages.

[0006] This problem is solved by an anchoring prong arrangement with the features of claim 1.

[0007] An anchoring prong arrangement for a medical implant – in particular for an intracardiac pacemaker – is disclosed, comprising a plurality of anchoring prongs which are preferably connected to and preferably project from an annular base, wherein each anchoring prong has a base section, an intermediate section adjoining the base section, and a tip adjoining the intermediate section for penetrating tissue, wherein in particular the respective base section adjoins the annular base, and wherein the respective intermediate section is at least partially coated with gold, and wherein the respective tip is free of gold, such that the respective tip has a cross-section that is smaller than the cross-section of the intermediate section adjoining the tip.

[0008] The base section preferably has at least one curvature away from the implant axis. The base section can have various shapes, including a curved and a straight section. The curved section can be formed by a curved segment, which may have one or more radii.

[0009] Preferably, the gold coating is applied to a straight part of the intermediate section.

[0010] The invention thus provides anchoring prongs whose tips are not coated with gold. This allows the anchoring prongs to penetrate the heart tissue better and with less force, since they are not thickened with gold at the point of penetration.

[0011] The invention thus advantageously resolves a technical contradiction. On the one hand, the prong tips are to be coated with gold so that they are easily visible under X-ray and the physician can use a pull test to determine whether the anchoring prongs are firmly embedded in the heart tissue. However, this gold coating thickens the prong tips. On the other hand, all anchoring prongs should be able to penetrate the heart tissue easily to ensure secure fixation of the implant with all anchoring prongs (especially four anchoring prongs). However, if too much force is required to penetrate the tissue, the anchoring prongs can buckle, and secure fixation is compromised. It is also likely that only two or three anchoring prongs, instead of four, will be securely fixed in the tissue because the others will not be able to penetrate it.For this purpose, the anchoring prongs should be as thin as possible so that they can easily penetrate the tissue.

[0012] The tips of the anchoring prongs are coated with gold, for example, using an electroplating process. In this process, the tips of the anchoring prongs are masked so that they are not coated with gold. This preserves the small cross-section of the anchoring prongs at tissue contact. The gold plating is applied only a short distance away from the tip. In practice, this means that the tissue is already punctured by the tip (a channel has already been created), and the slightly thickened, gold-plated portion of the anchoring prong can then penetrate more easily through this puncture. The result is significantly lower implantation forces and a higher probability of secure fixation, as the anchoring prongs cannot move out of place.

[0013] According to another aspect of the invention, a medical implant, in particular an intracardiac pacemaker (iLP), is disclosed which has an anchoring prong arrangement according to the invention.

[0014] According to a further aspect of the invention, a method for coating anchoring tines with gold is disclosed (in particular for producing the anchoring tine arrangement according to the invention), wherein the method comprises the steps: - Providing a plurality of anchoring prongs, each anchoring prong having a point, - Masking the tips of the anchor pins to prevent the tips from being coated with gold; - Carrying out a coating process, in particular an electroplating process, in which a section of the respective anchoring tine adjoining the corresponding tip is coated with gold, such that the respective uncoated tip has a smaller cross-section after the coating process than the gold-coated section adjoining the tip, and - Removal of the masks after the coating process.

[0015] In the following, embodiments of the invention, as well as further features and advantages of the invention, will be explained with reference to the figures. The figures show: Fig. 1 an embodiment of an anchoring prong arrangement according to the invention, Fig. 2 an embodiment of a medical implant according to the invention, in particular in the form of an intracardiac pacemaker, and Fig. 3 a method for coating anchoring zincs with gold.

[0016] Fig. Figure 1 shows an embodiment of an anchoring prong arrangement 1 according to the invention for a medical implant 100 (see Figure 1). Fig. 2), in particular for an intracardiac pacemaker, comprising a plurality of anchoring prongs 2, which are preferably connected to and preferably project from an annular base 3, wherein each anchoring prong has a curved base section 20, an intermediate section 21 adjoining the base section 20 and a tip 22 adjoining the intermediate section 21 for penetrating tissue, wherein in particular the base section 20 adjoins the annular base 3, and wherein the respective intermediate section 21 is coated with gold and wherein the respective tip 22 (and in particular the base section 20) is free of gold, so that the respective tip 22 has a cross-section that is smaller than the cross-section of the intermediate section 21 adjoining the tip 22.This type of intracardiac pacemaker (also known as a leadless pacemaker) is designed for implantation in any heart chamber. In this configuration, the base section 20 is curved away from the longitudinal axis of the implant and is shaped as a curve with a radius that tapers directly into the intermediate section. The intermediate section can be oriented as a straight line parallel to the implant axis or pointing towards the implant axis.

[0017] Furthermore, it shows Fig. 3 a method for coating the anchoring prongs 2 with gold in order to provide, for example, an anchoring prong arrangement 1 according to the invention.

[0018] The tips of the anchoring prongs are masked, for example, with insulating caps 4 made of, for example, silicone. The tips are inserted into the pre-slotted caps 4 (variant A) in Fig. 3) The caps 4 are primarily electrically insulating caps, since the electroplating process only works well on electrically conductive materials and the caps 4 should not be coated. A "dip" of the tips in liquid silicone 5 is also conceivable (variant B). Fig. 3) The silicone 5 is then preferably tempered to crosslink into a polymer. Only after this masking are the anchoring prongs immersed in an electroplating bath 6. The anchoring prongs are not completely immersed, but only to the point where the intermediate sections above the masked tips are adequately coated. After the coating process, the masking caps 4 are removed or the silicone dip 5 is peeled off.

[0019] The present invention advantageously enables lower implantation forces despite gold coating of the anchoring prongs, while simultaneously allowing the anchoring prongs to be seen in X-rays due to the adjacent gold coating.

Claims

[1] Anchoring prong arrangement (1) for a medical implant (100), in particular for an intracardiac pacemaker (100), comprising a plurality of anchoring prongs (2) which are preferably connected to and preferably project from a ring-shaped base (3), wherein each anchoring prong (2) has a base section (20), an intermediate section (21) adjoining the base section and a tip (22) adjoining the intermediate section for penetrating tissue, wherein the intermediate section (21) is coated with gold and the tip (22) is free of gold, such that the tip (22) has a cross-section that is smaller than the cross-section of the intermediate section (21) adjoining the tip (22).

Images