Slit lamps are a common ophthalmic instrument used for examining the ocular anterior segment by projecting a rectangular beam of light onto the eye. Conventional slit lamp configurations require the patient to stabilize themselves using a chin rest and forehead band limiting access to patients who are mobility impaired. We have therefore developed a robotic slit lamp to allow for autonomous imaging of a slit on the eye of individuals without physical head stabilization.
We designed our custom slit lamp projection system in Zemax OpticStudio. Illumination was achieved through the use of a white LED. We utilize a fly’s homogizer consisting of a pair of rectangular microlens arrays and a Fourier lens to homogenize the beam. A rectangular aperture that determines the size of the slit follows the Fourier lens and is relayed out onto the image plane. We designed custom mechanics to mount the slit projection optics, slit imaging cameras, and pupil tracking cameras to a Universal Robots UR3e utilizing CAD modeling in Fusion360.