Figure 2.

Slit lamp intensity, slit width, slit height, and slit angle actuators and controllers. Control relay for slit lamp intensity adjustment incorporated within the electronics module of the RCSL (A). Microcontroller BASIC stamp shown within the electronics module (B). The servomotor for slit width adjustment was mounted atop the slit lamp assembly (C). Slit width control, gear system (D). Since only 60° of rotation was required, a partial gear wheel was used to actuate the slit width. An 84-tooth gear wheel was used for the servo motor, and the partial gear wheel, if it were whole, would have 114 teeth, providing a gear ratio of 1:1.357. The servo for slit height adjustment was mounted adjacent to the slit lamp assembly (E). Custom brackets were fabricated to achieve a tight form factor. Slit height control, gear system (F). Since only 135° of rotation was required, a partial gear wheel was used to actuate the slit height. An 80-tooth gear wheel was used for the servo motor, and the partial gear wheel, if it were whole, would have 94 teeth, providing a gear ratio of 1:1.175. The servo for slit lamp angle control was mounted atop the axis of rotation of the slit (G). Custom brackets were fabricated to affix the servo inconspicuously, where the gear system is hidden underneath the bracket. Slit angle control, gear system (H). A 54-tooth gear wheel was used for the servo motor, and a 72-tooth gear wheel was fixed to the central column of the slit lamp, providing for ±60° of rotation using a gear ratio of 1:1.333.