A He-Ne laser position-detector for recording jaw movements: principle of operation and application in animal experiments.
A new equipment for recording jaw movements in animals by use of a He-Ne laser and a phototransistor (PhT) array is described. The principle of operation of this equipment is that the beam angle of the He-Ne laser is continuously controlled to irradiate the center of the PhT array by a feedback mechanism composed of a microcomputer (CPU) and XY scanners. The driving currents sent from the CPU to the XY scanners are utilized for monitoring two-dimensional jaw movements. The linearity of this recording system is preserved both vertically and horizontally over a range of 11 mm from the center of the scanning field of the laser beam within less than 1.5%, which is satisfactory for monitoring rabbit jaw movements. When this equipment was applied to the rabbit, there was no sign of disturbance to the animal during chewing carrots.
D000818:Animals; D007568:Jaw / Q000502:physiology*; D007834:Lasers; D008409:Mastication; D008838:Microcomputers; D009068:Movement; D010827:Physiology / Q000295:instrumentation*; D011187:Posture; D011817:Rabbits