SIMULTANEOUS ACQUISITION OF SPATIOTEMPORAL AND LOAD/PRESSURE DATA IN THE WALKING RAT

K.A. Clarke 1, S.A. Heitmeyer 2, A.G. Smith 1 and Y.O. Taiwo 2

1 Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
2 Procter and Gamble Co., Miami Valley Laboratories, Cincinnati, U.S.A.

Gait analysis in the rat has proved to be useful in the detection of many types of pathophysiological change.We report here an extension of our previous techniques to permit simultaneous collection of several data types. The detection system is built into a glass-floored, plexiglass chamber (120 x 12 x 12 cm) sited in a dedicated, soundproofed room. Each rat is placed individually in the chamber and allowed to ambulate spontaneously. The central 24 cm section is made up of six, closely fitting, but not touching, 8 x 10 cm, 0.5 cm thick, high quality glass plates. Four of the plates form the platforms of load cells to measure vertical reaction forces and four (two common), of the plates are internally illuminated by 8 W cowled fluorescent tubes. Light is scattered at the surface when an object, such as a paw, makes contact, and is illuminated at an intensity proportional to the closeness of contact. Placement of a suitable transduction material on the glass surface allows pressure distributions contributing to particular loads to be calculated. Cameras below the chamber capture the footfalls, which appear as bright spots of light. Output from the load cells is fed through an A/D system of a computer and transmitted as a video signal to another laboratory for recording. This is combined with the camera output using a video mixer and saved to VCR. Analysis involves replaying the tape through a frame grabber with suitable associated software. This methodology is currently employed in a number of research projects in this and other laboratories.

I acknowledge the generosity of the Procter & Gamble Co. to this work.


Poster presented at Measuring Behavior '96, International Workshop on Methods and Techniques in Behavioral Research, 16-18 October 1996, Utrecht, The Netherlands