FR2886490A1 - Implantable transponder for e.g. cat, has bobbin formed of tens of non joint turns and connected on pads by electric welding, and rod and turn assembly integrated in glass ampoule, where transponder uses specific frequency - Google Patents

Abstract

The transponder has a band (1) comprising transversal bands each composed of two surfaces in which one surface supports a silicon unit. The other surface is very fine and permits to implement a bobbin (7) of the transponder. A ferrite rod (3) is positioned below a fine part of a transversal band (4). The bobbin is made of a non-insulated metal wire and is formed of tens of non joint turns, and connected on respective pads (8, 9) by an electric welding. An assembly of the rod and the coil turns is integrated in a glass ampoule, where the transponder uses a frequency of 13.56 megahertz.

Description

- 1 -

  The invention describes an implantable transponder of very small size and its method of manufacture.

  It is known as described in patent US5211129 that implantable transponders exist, these transponders are generally in the form of a small glass bulb, in particular in patent US5963132.

  These transponders are generally composed of a coil associated with an electronic element integrating the functions of communication and data storage. Said coil and the electronic part are encapsulated in a small glass bulb for reasons of biocompatibility.

  These transponders have a substantial size, more than 2 mm in diameter and a minimum length of 8 mm. This size is very acceptable for large animals such as cats, dogs, horses ...

  For small animals, such as, for example, laboratory mice, birds, small fish, the size of the transponder becomes too large and difficult to accept.

  In addition, the identification of laboratory animals must be done as soon as possible after the birth of the animal, the size is therefore a key element to reduce the trauma of implantation.

  The technology of existing transponders uses a frequency of the order of one hundred kilohertz, which implies a large reception coil and thus results in a large size of the transponder.

  The invention consists in the significant improvement of these transponders as to the size and method of manufacture thereof, thus allowing implantation in very small animals.

  The transponder, in one embodiment of the invention, uses a high frequency, greater than ten megahertz, which allows to significantly reduce the size of the coil.

  In this embodiment of the invention, the frequency used is 13.56 megahertz, and the glass ampule has an outside diameter of less than 1 mm and a length of less than 6 mm. - 2 -

  We will describe a method of realization of these transponders, this method makes it possible to automate the phases of production and consequently to reduce the cost of production.

  One form of implementation of this method consists in the use of a flexible printed circuit board support such as polyimide or polyester film, for example, pre-cut according to FIG.

  Figure 1 more particularly describes the drawing of an embodiment of this printed circuit.

  Said printed circuit is a strip (1) containing guide holes (2) and transverse strips (3) and (4).

  Each transverse strip is composed of two surfaces (3) and (4), the surface (3) is shaped sufficiently large to support the silicon element, the surface (4) is very thin and will allow the implementation of the coil transponder. Each transverse strip of this printed circuit comprises three conductive pads of precious metal or not (5), (6) and (7). An insulating material, such as varnish or other, covers the entire transverse band, with the exception of the ranges (5), (8), (9), (10) and (11). These ranges provide the connection with the coil and the silicon element.

  A variant of greater shape of the pads (7) and (6) allows the installation of the silicon element directly on these beaches microbillage.

  Pre-cuts (12) make it very easy to extract the transverse strips very easily at the end of the assembly.

  Figure 2 depicts a mounting form of the silicon element and coil associated with a ferrite magnetic material rod for example.

  The silicon element (1) is glued to the reception area (2), the small rod of magnetic material (3) is positioned, glued or not, below the thin portion of the transverse strip (4).

  Wired connections (5) and (6) are made of precious metal or not by a known method of microelectronic connection including electrical welding or ultrasound.

  The coil (7) is made of uninsulated metal wire, precious or not, said coil consists of a few tens of non-contiguous turns, connected to the respective ranges (8) and (9) by a known method of microelectronic connection including electrical welding or ultrasound. In a variant of the invention, a binder and nonconductive material is disposed on the turns and / or the silicon element to allow the retention thereof to avoid any variation in the overall inductance and electromagnetic parameters.

  At the end of the assembly, the electronic assembly (1) is detached and inserted in a biocompatible glass tube (2), closed at one end, as described in FIG. 3. The flexibility of the printed support (3) makes it possible to position correctly the electronic assembly in said tube (2).

  In a variant of the invention, a binder and non-conductive material is placed in the tube to allow the assembly to be held.

  The tube is then closed to seal by a known means identical to the other end or any other means of closure such as flame or heat input.

  A variant of the closure of the tube is the use of a resin or a biocompatible material for sealing. - 4 -

Claims (4)

  1) Implantable transponder of the shape of a cylinder rounded at the ends of an external diameter of less than 1 mm using a frequency of 13.56 MHz characterized in that it consists of a ferrite bar around which is wound a few tens non-contiguous turns of non-insulated wire associated with a silicon-based electronic circuit and whose assembly is integrated in a sealed glass bulb.   2) implantable transponder according to claim 1 characterized in that said silicon-based electronic circuit is connected to a flexible support containing conductive tracks to make the connections with both ends of the coil.   3) implantable transponder according to claim 1 or 2 characterized in that said flexible carrier with conductive tracks is a polyimide film or polyester.   4) implantable transponder according to claim 1 characterized in that said glass bulb is sealed by a biocompatible material.