Retainer for murine specimens and test equipment

A device for immobilizing live animals to permit laboratory examination thereof. The device consists of a base plate to which guides and pins are attached, and with cantilever arms disposed on and rotatably and vertically movable relative to the pins. The specimen to be retained is placed on the base plate between a pair of guides, and the arm over these guides is lowered onto the specimen. Thus, the specimen is confined but not surrounded. Guides, recesses, and holes in the arms allow the attachment of various fixtures or instruments to the retained animal(s).

BACKGROUND OF THE INVENTION 
Restraint mechanisms for laboratory experimental animals are widely used. A 
variety of restraining devices are commercially available. These are 
typically bridge-type apparatuses which restrict accessibility to the 
specimen. Furthermore, devices specialized to hold one species of animal 
(especially if intended for one size of the species) may hold the animal 
securely, but such devices are not versatile, and less specialized devices 
adaptable to many sizes may not hold any of them securely enough. The 
prior art does not make provision for holding test equipment such as 
electrodes or sensors adjacent to the specimen. There is, thus, a definite 
need in the art for a retainer more adaptable, flexible, and versatile in 
design. 
Accordingly, it is an object of the present invention to provide a retainer 
which is adaptable to accommodate different kinds, sizes, and numbers of 
animals. 
It is a further object of the present invention to provide a retainer which 
allows open access to the specimens. 
It is yet another object of the present invention to provide a retainer 
with provisions for holding test equipment or sensors, or for attaching 
them to the animals. 
SUMMARY OF THE INVENTION 
The foregoing and other objects are attainable according to the present 
invention by providing a flexible design for a simple murine specimen 
retainer. 
The preferred embodiment of the present invention consists of a base plate 
to which are attached guide blocks and pins with cantilever arms mounted 
on the pins. A specimen to be retained is clamped under a cantilever arm, 
against the base plate, with the guide blocks serving to prevent sideways 
motion. 
In addition, the preferred embodiment of the present invention features 
guides, recesses and holes in the cantilever arm facilitating the 
attachment of a variety of equipment, electrodes, or sensors in proximity 
to the restrained animals. 
The base plate is made arbitrarily large to accommodate a plurality of sets 
of guides, pins, and arms, these sets being small relative to the size of 
the specimen intended to be restrained, whereby access to the sides and 
ends of the specimen is free and convenient. The invention is therefore 
simultaneously practicable on a quantity of specimens and instruments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention consists of a base plate 10, to which a pair of 
parallel guide blocks 11 for each specimen are attached. Holes 20 secure 
pins 12 vertically in the base. Each of the pins 12 horizontally supports 
a cantilever restraining arm 13, through a hole 21 in the arm and of a 
diameter slightly larger than the pin. The length of the base plate 10, 
and the corresponding number of sets of guide blocks 11, pins 12, and arms 
13 positioned on the base plate, are selected according to the 
requirements of the intended application. 
The restraining function of the invention is accomplished by lowering arms 
13 onto the item to be held, which may be either a murine specimen 22, or 
test equipment comprehensively designated 18. An important feature of the 
invention is its capacity to hold both a live specimen 22 and a sensor or 
electrode 17, together under one arm, as shown in the drawing at the left 
end of base plate 10. Test equipment 18 is connected to electrode 17 by 
test probe leads 25. 
Once lowered, the arm may be held in place by the force of the compressed 
specimen pushing upward on the arm which tilts the free end of the arm up, 
whereby the bottom outer edge and top inner edge of hole 21 bind against 
pin 12, or the arm may be secured by the use of set screw 14. 
At least some of the restraining arms 13 are fitted with a foam rubber 
cushion 15 which serves to spread the pressure of the arm on the specimen 
being held, thereby cushioning and holding the specimen more securely. The 
function of foam cushion 15 is duplicated by another foam cushion 19, 
mounted between the guides 11 and serving to contact and secure the 
underside of the specimen. 
Depending upon the application intended for the invention, others of the 
restraining arms are provided with an opening 16 through which test probe 
leads 25 may be threaded. The pins 12 are of sufficient length to permit 
both a murine specimen 22 and sensor plates 17 to be held together under 
one arm. 
Although the base plate 10, guide blocks 11, pins 12 and arms 13 of the 
preferred embodiment are fabricated from acrylic plastic, any suitable 
material may be utilized for construction thereof. 
Although the invention has been described relative to a specific embodiment 
thereof, it is not so limited and numerous variations and modifications 
thereof will be readily apparent to those skilled in the art in the light 
of the above teaching. It is therefore to be understood that within the 
scope of the appended claims the invention may be practiced otherwise than 
as specifically described.