Apparatus for locating medical implants - Patent application

Abstract

An apparatus is described for percutaneous localization of a medical implant placed subcutaneously within the body, the medical implant having an implant surface on which at least one electric coil is disposed, the electric coil having at least one coil winding surrounding an area of ​​the implant surface, the apparatus further comprising an extracorporeally operable unit having attached thereto a plurality of electric coils adapted in shape and size to the electric coils disposed on the implant side and connected to an electric control unit and a signal transmission means, the signal transmission means generating a perceptible signal at least at the time of maximum inductive coupling between the external coil and the implant coil. [Selected Figure] Figure 2

Description

[Technical Field]

[0001] The present invention relates to a device for percutaneous localization of a medical implant placed subcutaneously inside the body, the medical implant having an implant surface on which at least one first electric coil is arranged, the electric coil having at least one coil winding surrounding an area of ​​the implant surface. For the purpose of localization of the coil winding, an extracorporeally operable unit is used, which unit is equipped with at least one electric coil connected to an electric control unit and to signal transmission means, by means of which the maximum possible coil overlap between the internal coil and the external coil can be detected in the course of inductive detection. [Background technology]

[0002] EP 1052935 discloses a system and method for locating an implantable drug delivery device that is implanted immediately beneath the skin. The drug delivery device includes a drug reservoir, the walls of which have a septum that is oriented toward the skin surface during implantation to allow for multiple refills. Filling such an implanted drug reservoir requires accurate knowledge of the orientation and position of the subcutaneously located plenum, allowing the physician to perform the filling process using an injection device with a single skin puncture with an injection needle, without further strain on the patient.

[0003] To accurately locate the septum placed inside the body, an electric coil surrounding the septum is provided on the implant side, and this coil is connected to an electric energy source and an electric control device mounted inside the drug release device and can operate as a transmitting antenna. It is effective to locate the location of the transmitting antenna mounted on the implant side, i.e., the septum surrounded by the transmitting antenna, using an externally operable implant location antenna device having three air-core coil antennas mounted evenly distributed around the circumference. To do this, the external implant location antenna device must be moved along the surface of the patient's skin until the three air-core coil antennas of the location antenna device, which are evenly distributed around an imaginary circumference, are concentrically aligned with the transmitting antenna on the implant side.

[0004] As a navigation aid, the physician uses an optical signal transmission means, for example in the form of an illuminable arrow mark, additionally provided on the locating antenna device, the illumination of which is based on the ratio of the electrical energy inductively coupled by each of the three air-core coils. If the electrical energy received by all three air-core coils is the same, the implant locating antenna device is located concentrically above the transmitting antenna attached to the implant. A penetration guide for an injection needle is provided in the center of the implant locating antenna device, allowing the physician to locally puncture the underlying septum for filling the drug reservoir.

[0005] US 2008 / 028127 A1 describes an apparatus for percutaneous localization of implants placed inside the body, which, similar to the above-mentioned location system according to EP 1 052 935 A1, has an implant location antenna device operable outside the body that can slide along the skin surface to find a coil placed inside the body.

[0006] U.S. Patent Application Publication No. 2017 / 0100056 discloses a communication system between a coil assembly disposed inside the body and a coil array assembly movably disposed outside the body, which is capable of transmitting signal data and energy between the individual coils outside the body and the coils disposed inside the body, whereby the coils inside the body have a larger coil diameter than the individual coils outside the body provided in the array assembly. Summary of the Invention [Problem to be solved by the invention]

[0007] The problem underlying the present invention is to improve an apparatus for percutaneous localization of a medical implant placed subcutaneously in the body, the medical implant having an implant surface on which at least one electric coil is arranged, the electric coil having at least one coil winding surrounding an area of ​​the implant surface, and further including an extracorporeally operable unit to which at least one electric coil is attached, connected to an electric control unit and signal transmission means, in order to minimize the time and concentration required by the physician to manually center the extracorporeally operable unit relative to the implant-attached electric coil. At the same time, it is important to ensure that the subsequent needle puncture is performed so as to accurately hit the skin and the interior area of ​​the implant-attached electric coil. In particular, it is important, on the one hand, to reduce the burden on the physician to perform this procedure, and, on the other hand, to protect the patient from possible accidental punctures. [Means for solving the problem]

[0008] The solution to the problem underlying the present invention is set forth in claim 1. Features which advantageously improve the device according to the invention are set forth in the dependent claims and can be seen from the following description given with reference to examples.

[0009] The device according to the invention for percutaneous localization of subcutaneously placed medical implants in the body according to the preamble features of claim 1 is characterized in that the extracorporeally operable unit comprises a plurality of further electric coils, the coil diameter of which is approximately equal to the coil diameter of the first coil or smaller than the coil diameter assigned to the electric coil attached to the implant side, and the electric coils attached to the extracorporeally operable unit are connected to an electric control unit and to signal transmission means, or at least to signal transmission means respectively, which generate a perceptible signal identifying the electric coil having at least the greatest inductive coupling when there is a maximum inductive coupling between at least one of the electric coils and the electric coil attached to the implant side.

[0010] The device according to the invention avoids the time-consuming search process for the physician to find the exact position of the implant-side mounted electric coil, which requires a highly accurate centering process to be performed by controlling the relative movement of a known extracorporeally operable unit while observing perceptible, preferably visual, navigation information. The idea according to the invention is to provide an extracorporeally operable unit in the form of a surface substrate in the form of a mat or film made of a skin-compatible, flexible, preferably light-transmitting material, on which a plurality of electric coils are arranged with the highest possible spatial packing density.

[0011] Preferably, the electric coils are arranged indirectly or preferably directly adjacent to one another on the surface of the mat-like planar substrate or inside the planar substrate along the first arrangement plane, so that the proportion of the area inside the first arrangement plane that does not each contain at least one electric coil is as small as possible, preferably minimized.

[0012] The surface shape and surface size of the mat- or film-like planar substrate, in which multiple electric coils are evenly distributed at least in a predetermined area and arranged to cover the surface as evenly as possible, are preferably selected so that by simply abutting or placing the planar substrate against the skin surface in the area where the electric coil attached to the subcutaneously placed implant side is most likely to be located, at least one electric coil of the multiple electric coils attached to the inside of the planar substrate will be located within a projection above the electric coil arranged on the implant side.

[0013] In order to accurately determine the position of the electric coil attached to the implant side placed under the skin, a control unit, which is also indirectly or directly attached to the mat-shaped planar substrate, compares the electric energy input into all the electric coils attached to the planar substrate side during the induction process and detects the electric coil or coil group consisting of multiple electric coils that can measure the maximum electric energy during the maximum inductive coupling due to the maximum overlap with the coil on the implant side.

[0014] The electric coil or coil group that is most inductively coupled to the embedded electric coil is directly optically marked by a signaling means, preferably in the form of a light emitter. In a preferred embodiment, each electric coil inside the matte surface substrate is provided with a light emitter, which allows a perceptible coil identification when one of the light emitters emits light. Preferably, the light emitter is in the form of an LED or a fluorescent or phosphorescent material that is attached directly to each electric coil or is provided in the coil material.

[0015] The light emitters attached to all of the electric coils preferably emit electromagnetic radiation with wavelengths in the visible spectrum. For this reason, the matte surface substrate is made of a skin-compatible material that at least partially surrounds the electric coils as a matrix, and is made of a light-transmitting material, preferably a polyamide or silicone-based plastic material. Furthermore, the surface substrate, which flexibly conforms to the surface shape of the body, allows for almost unhindered puncture with an injection needle. Thus, after identifying at least one electric coil with the greatest inductive coupling to the electric coil located on the implant side, the doctor can insert the injection needle into the surface substrate and the septum, which is located just below the skin surface in a projected view, as centrally and unhindered as possible within the circular surface area surrounded by the electric coils, each marked with a light emitter, for the purpose of filling.

[0016] To ensure that the coil marked with the greatest inductive coupling in each case is always positioned above the electric coil attached to the implant side in a projection onto the skin surface, the coil diameter of each electric coil attached to the planar substrate is selected to be at most the same as, and preferably smaller than, the coil diameter of the electric coil attached to the implant side. All electric coils arranged on the planar substrate side have the same coil diameter.

[0017] In another preferred embodiment for forming a unit operable outside the body, at least one second set of electric coils is provided inside a mat-shaped planar substrate, the electric coils of the second set being arranged indirectly or directly adjacent to one another or in pairs and partially overlapping one another along a second arrangement plane parallel to the first arrangement plane, so that in a perpendicular projection onto the first and second arrangement planes, the electric coils of both arrangement planes partially overlap one another, thereby ensuring that, under inductive coupling between one of the electric coils and an electric coil attached to the implant side, the electric coil that preferably appears visually perceptible based on the maximum inductive coupling in comparison with all other electric coils arranged on the planar substrate side is precisely positioned above or inside the electric coil arranged on the implant side.

[0018] The invention will now be illustrated by way of example with reference to the drawings, without limiting the general inventive idea. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 shows a mat-like planar substrate with multiple electrical coils and one electrical coil attached to the implant side. [Figure 2] 1 shows an example of a mat-shaped planar substrate with electrical coils distributed and attached to two placement planes. DETAILED DESCRIPTION OF THE INVENTION

[0020] FIG. 1 shows a mat-shaped area substrate 1 made of a flexible, skin-compatible material, preferably a silicone-based plastic, incorporating a number of identically shaped and sized electric coils 2. All electric coils 2 are electrically connected to a control unit 3, which is connected directly or indirectly to a source of electric energy, preferably in the form of a battery or accumulator 4. As can be seen in FIG. 1, the electric coils 2 may be arranged directly adjacent to each other along a plane inside or on the area substrate 1. In this case, intermediate areas that do not contain electric coils are formed between the coils. Alternatively, to minimize or, as far as possible, eliminate such intermediate areas, it is proposed to arrange the electric coils 2 so that they overlap each other along a plane.

[0021] The mat-like planar substrate 1 is placed on the skin surface 6 of the patient P in order to locate the implant 5. The medical implant 5 is a drug pump device having an implant surface 7 with at least one self-sealing port 8, in particular in the form of a diaphragm, which provides a fluid-tight seal to a reservoir volume inside the medical implant. In the implanted state, the implant surface 7 is oriented substantially parallel to the skin surface 6, so that the diaphragm 8 is located in the vicinity of the skin surface 6. Furthermore, the diaphragm 8 is surrounded by an electric coil 9 which is operable via a control unit (not shown) contained inside the medical implant 5 and a source of electric energy in the form of a transmitting antenna.

[0022] For the purpose of identifying the position of the diaphragm 8, the mat-shaped sheet substrate 1 shown in FIG. 1 is placed on the skin surface 6 of the patient P in the area of ​​the medical implant 5 in a covering and contoured manner. The area size of the sheet substrate 1 and the planar arrangement and extent of the multiple coils 2 are selected so that even if a physician has only insufficient information about the position of the implant 5, the sheet substrate 1 can be placed on the patient's skin surface in such a way that at least one coil 2 of the sheet substrate geometrically overlaps with the coil 9 arranged on the implant side, without the need to subsequently correct the position of the sheet substrate.

[0023] The multiple electric coils 2 arranged on the mat-like planar substrate 1 each function as a receiving coil capable of receiving and absorbing electric energy during the inductive coupling process. This electric energy can be detected, measured, and compared between the individual electric coils by the control unit 3. From the multiple electric coils 2, the coil with the greatest inductive coupling with the electric coil 9 arranged on the implant side and thus the greatest electric energy is identified. Alternatively, the electric coils arranged on the mat-like planar substrate can operate actively, i.e., as transmitting coils, and at least one electric coil arranged on the implant side can operate passively. In this way, the electric energy source on the implant side is not loaded during the localization process. In this case, the electric coil attached to the mat-like planar substrate with the greatest inductive coupling with the electric coil on the implant side is optically marked.

[0024] Each electric coil 2 integrated into the matt surface substrate 1 is individually equipped with a light emitter 10, for example in the form of an LED. The electric coil 2 with the greatest inductive coupling among all the electric coils present is * To mark and visualize this electrical coil 2 * The light emitters 10 are activated by the control unit 3, which allows the physician to determine which electric coil 2 is illuminated at any given time. *1 shows an illuminated coil 2 with a light source 10 shown diagrammatically. * are shown separately and enlarged.

[0025] It is important to position the injection needle preferably in the middle inside the circular surface 2 ″ defined in the radial direction by the respective illuminated electric coils 2 .

[0026] 2 shows an embodiment of a mat-shaped planar substrate 1, in which a plurality of electric coils 2 comparable to the embodiment shown in FIG. 1 are arranged along a first arrangement plane E1, i.e., the electric coils 2 arranged in the first arrangement plane E1 are arranged in an array of equal size and directly adjacent to one another. Furthermore, a plurality of other electric coils 2' are arranged in a second arrangement plane E2 oriented parallel to the first arrangement plane E1, with the inner coils 2' of the second arrangement plane E2 being offset by one coil radius relative to the inner coils 2 of the first arrangement plane E1. Thus, in a projection perpendicular to the two arrangement planes E1 and E2, the electric coils 2, 2' of the different arrangement planes E1 and E2 overlap. This increases the reliability of accurately orthogonally positioning at least one coil above and within the range of the electric coil 9 attached to the implant, allowing the surgeon to accurately identify the electric coil 2 illuminated by a suitable light source. * When puncturing the inner region of the implant, the septum 8 of the implant located in the body immediately below it is punctured precisely by the injection needle 11.

[0027] The device according to the present invention for percutaneous localization of a medical implant placed under the skin in the body can quickly display and identify an electric coil located above a diaphragm placed in the body by simply placing a mat-shaped planar substrate provided with a plurality of electric coils on the skin surface, without any searching movements. Preferably, the planar substrate has a surface that is adjusted to be as non-slip as possible on the skin surface, for example, suitable for forming an adhesive-free adhesive surface bond. [Explanation of symbols]

[0028] 1: A mat-shaped surface substrate 2: Electric coil 2': Electric coil in the second layout plane 2 * : Illuminated electric coil 3: Control unit 4: Electrical energy source 5: Medical implants 6:Skin surface 7: Implant surface 8: Diaphragm 9: Electric coil placed on the implant side 10: Light source 11: Syringe needle E1, E2: First and second placement planes

Claims

1. 1. An apparatus for percutaneous localization of a subcutaneously placed medical implant within a body, the medical implant having an implant surface on which at least one first electrical coil is disposed, the first electrical coil having at least one coil winding surrounding an area of ​​the implant surface, the apparatus further comprising an extracorporeally operable unit having attached thereto a second electrical coil electrically and physically connected to an electrical control unit and a light emitter; the unit operable outside the body formed in the form of a planar substrate has a plurality of second electric coils, and the coil diameter of the second electric coils is set to be approximately equal to or smaller than the coil diameter of the first electric coil attached to the implant side; the light emitter is disposed to surround each of the second electric coils; the first set (2) of second electric coils attached to the extracorporeal operable unit (1) are arranged along a first arrangement plane (E1) a) side by side with one another or b) in pairs, each partially overlapping; The second electric coil attached to the surface of the planar substrate or inside the planar substrate is connected to the electric control unit, and the second electric coils are each connected to at least one of the light emitters, and are arranged and configured so that, at the time of maximum inductive coupling among all the second electric coils present, at least one of the second electric coils attached to the unit operable outside the body and the at least one first electric coil attached to the implant side can be identified externally by the light emission of the light emitter driven by the control unit of at least the second electric coil having the maximum inductive coupling.

2. 2. The device according to claim 1, wherein the second set of second electric coils (2') attached to the extracorporeal operable unit (1) are arranged in a second arrangement plane (E2) a) side by side or b) in pairs partially overlapping each other, and the second arrangement plane (E2) is oriented parallel to the first arrangement plane (E1) so that in a perpendicular projection onto the first and second arrangement planes, the second electric coils (2, 2') in both arrangement planes (E1, E2) partially overlap each other.

3. 3. The device of claim 1 or claim 2, wherein the light emitter comprises an LED.

4. the medical implant having at least one reservoir volume defined by at least one of the areas of the implant surface surrounded by the coil winding; the region is formed as a self-sealing port for filling with an injection device; 4. An apparatus according to any one of claims 1 to 3.

5. 5. The device of claim 4, wherein the region is formed in the form of a self-sealing diaphragm.

6. 6. The device according to claim 1, wherein the planar substrate is made of a light-transmitting material and has an adhesive surface for removably and firmly adhering to a skin surface.

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