Transponder holding case as implant in animal breeding and keeping

In order to fulfill the requirements in terms of biological compatibility and mechanical stability, a transponder-holding case is provided as implant in animal breeding and keeping, which case consists of a first case section and a second case section made of a biologically compatible synthetic material, with the two case sections being designed for being detachably fastened at one another, preferably through a self-sealing and self-locking threaded joint, so as to form a hermetically sealed holding space for a transponder to be received therein. For an improvement of the position-retaining function in the animal body at least one of the case sections presents at least one formed-in portion on ist outside, and at least on the outside of one case section a receiving area is provided for a preferably laser-engraved identifier mark.

BACKGROUND OF THE INVENTION 
The invention relates to a transponder-holding case as implant in animal 
breeding and keeping. 
The application of transponder technology in breeding and keeping herds and 
flocks of animals for the food chain as a forgery-proof and lasting 
instrument of identification and verification is still in the pilot 
application phase. The topical problems of bovine spongiforme 
encephalopathy (BSE) and hormone administration, as well as the resulting 
controlling legislation are, however, going to ensure a world-wide 
application of this technique before long. 
In correspondence with the transponder technology transponders are 
implanted in a part of the body of the animals where they cannot provoke 
any impairment of the well-being, the movements or the growth and where 
additionally the reading by means of a transponder-reading device is 
possible in a functionally reliable manner. Control via transponders 
offers a solution for herd and flock management, the observation and 
pursuit of owners, the case history and origin, with this technology 
replacing earmarks, tattoos and brand marks. 
So far passive transponders have become known which are not equipped with 
an energy source of their own. The passive transponders are energized via 
a magnetic low-frequency field of a hand-held reading device, with the 
disadvantage that activation is possible only within a small range. 
Meanwhile active transponders have been developed, too, which consist of a 
round ferrite core, 5 to 20 mm long, with a copper wire coil wound thereon 
and a board with an edge length of roughly 5 mm for mounting the 
transponder chip, as well as of a lithium power pack. Such active 
transponders permit the identification over distances longer than the 
range of passive transponders but they require a holding case, both for 
ensuring a perfect function and as a result of the materials involved, 
which case keeps any mechanical loads in the animal body away from the 
transponder, is easy to retrieve inside the animal body, and does not lead 
to inflammations of the surrounding tissue. 
In initial field trials glass cases have been applied already which did not 
furnish satisfactory results, however, because they involve a high risk of 
glass break, of migrations inside the animal body, and of inflammatory 
processes in the surrounding tissue. 
OBJECTS AND SUMMARY OF THE INVENTION 
The present invention now aims at providing a transponder-holding case as 
implant in animal breeding and keeping, which takes mainly the 
requirements in terms of tissue tolerance and mechanical stability into 
account. 
In accordance with the invention this aim is reached by a 
transponder-holding case presenting the features defined in claim 1. 
Preferred further embodiments of the holding case are covered by the 
dependent claims. 
In accordance with the invention hence a two-part case is provided which is 
made of a biologically compatible synthetic material and hence prevents 
inflammation of the surrounding tissue or encapsulation with the 
connective tissue. The inventive case expediently resists any loads 
occurring in the envisaged applications, and the configuration of the case 
prevents expediently any "migration" in the body of the animal. 
The preferably provided detachable fastening of the case parts by means of 
a threaded joint allows for a dust-proof and fluid-proof screw connection 
which permits also a use of the case in other applications, e.g. 
applications exposed to environmental nuisance. 
Once the case has been implanted in an animal body both the case size and 
the shape of the size expediently ensure that there is no "migration" of 
the case in the animal body. To this end the case is provided with notches 
or recesses, respectively, on its outside and has an axially symmetrical, 
preferably cylindrical, configuration so that it is also extremely simple 
to produce as turned part. Moreover it is also possible to design a 
sufficiently voluminous holding space for accommodation of fairly complex 
electronic systems, too. 
A special polytetrafluoroethylene (PTFE) substance is preferably used as 
biologically compatible raw material. However, other biologically 
compatible synthetic materials may be employed, too, which fulfill the 
requirements in terms of a sufficient mechanical stability and a hermetic 
sealability of two case sections. 
The envisaged threaded joint is preferably designed to be self-sealing and 
self-locking and can be unscrewed for detaching the case sections from one 
another only forcefully. 
Another expedient provision is the formation of a holding surface for a 
preferably laser-engraved identifier mark on the outside of the case so as 
to render the case identifiable. 
In accordance with a preferred embodiment the case has a cylindrical shape 
and a length of roughly 40 mm, with an outside diameter of some 16 mm, 
with the transponder-holding space being roughly 30 mm long and having a 
diameter of 8 mm, approximately.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows a longitudinal section through a first case section 10 which 
is adapted for being detachably screwed to a second case section which is 
illustrated in FIG. 2. The case sections 10 and 20 are made of a 
biologically compatible synthetic material, e.g. a special PTFE material. 
They have an axially symmetrical shape and are easy to manufacture as 
turned part. 
The first case section 10 is provided with a cylindrical section 11 and a 
rounded closed end 12 which is joined through a notch 13 opposite to the 
cylindrical section 11. The notch 13 may also be designed as rectangular 
recess instead of the sawtooth step as shown in FIG. 1. An axially 
symmetrical cylindrical holding space 14 is formed inside the first case 
section 10, which extends from the region of a connecting surface 15, 
which is provided for joining the first case section 10 to the second case 
section 20, up to the terminal section 12 in the manner of a blind bore. 
The cylindrical section 11 moreover includes an internal thread 16 in the 
region of the connecting surface 15, which has a wider diameter, as 
compared against the diameter of the holding space 14, and is chamfered 
relative to the connecting surface. 
The dimensions of a preferred embodiment of the first case section 10 are 
indicated in FIG. 1. What is clearly visible is the fact that the 
thickness of the wall surrounding the holding space 14, and equally the 
wall thickness of the case section 20, is at least equal to the outside 
diameter of the holding space 14. 
The design of the second case section 20 according to FIG. 2 corresponds to 
the design of the first case section 10, with the exception of an 
externally threaded connecting piece 26, which projects beyond a 
connecting surface 25, instead of the internal thread 16. The second case 
section 20 is hence also provided with a cylindrical section 21, a 
terminal section 22, a recess or a notch 23, respectively, as well as with 
a holding space 24. 
For application of the transponder-holding case the transponder as such is 
initially placed into the holding space 14 or 24, respectively, whereupon 
the two case sections 10 and 20 are screwed together until the connecting 
surface 15 is placed near or on the connecting surface 25 of the second 
case section. The particular design of the thread with flanks changing in 
the screwing direction ensures that the screw joint is hermetically sealed 
by self-sealing action and that the threaded joint is self-locking at the 
same time.