Abstract: A method of calibrating a laser galvanometer to an XY stage by directing a defocused laser beam through a galvanometer and onto an XY stage and re-centering the laser beam at subsequent positions on the XY stage. Offsets are calculated based on the required movement of the galvanometer to recenter the laser beam at each of the positions on the XY stage. The laser beam may be defocused by focusing the laser beam at a distance Z both above or below the XY stage for each position and then calculating the offset for each position by averaging the values calculated at the focus distances Z above and below the XY stage. The laser beam may also be defocused by passing it through a pinhole.

Abstract: An apparatus for the automatic delivery to an animal of a beneficial agent such as analgesia by infusion with the pain of the animal being taken into account when determining the rate of dispensing the agent. As the pain experienced by an animal and therefore its distress is manifested in increased agitation, the apparatus includes elements for the measurement of the frequency and amplitude of an animal's movement and the generation of a trigger signal when the either the frequency or the amplitude exceeds a predetermined threshold. The trigger can be used to generate a visual or audible alarm. The apparatus also preferably includes a dispensing means for delivering doses of beneficial agent to the animal in response to the trigger signal. The apparatus serves primarily to reduce the post-operative distress experienced by an animal by providing for timely administration of analgesic compounds.