This telescope was used in a laser angeoplasty unit.  It has a zoom feature.

This QYZ positioner was developed to track the human eye in a keratometer.  A similar positioner for the same instrument payload was developed using band drives instead of the leadscrew-stepping motor combination pictured.   Feedback was provided by the instrument payload. The band drive unit was investigated as a lower cost option but was found to yield an inordinate settling time.   Several sizes and styles of bands were investigated using FEA but, in the end, the performance of the leadscrew drive prevailed over cost.

This was developed for another consulting firm to produce proprietary catheters for use in angeoplasty.  The figure is representative of the actual unit.  Several linear control axes were used as well as process controls for control pneumatics, cooling air, and heating air.  A programmable sequence controller using ladder logic with several I/O expansion modules provided the control.  Linear motion utilized stepping motors and photoelectric sensors with flags for feedback.