Abstract: A corneal topography system incorporating a handheld unit, a base unit and a computer. The handheld unit includes a placido projector, a light source and a camera that receives the image of the placido image being reflected off of the patient's cornea. The light source is preferably comprised of a lightweight luminescent panel such as an EL panel. The handheld unit further includes a laser and a display that are used to properly align the handheld unit with respect to the patient's cornea into a desired orientation. The resulting reflected image is captured when the handheld unit is in the desired orientation and this image can then be used to obtain corneal topography data for the patient's eye.

Abstract: An apparatus for providing hitless by-pass switching for signal flow paths on a circuit board. The switches for establishing the by-pass path(s) are mounted adjacent to the connector into which the board is inserted. The circuit board has mounted thereon an apparatus which engages the by-pass switches in a manner so as to open the switches and maintain them open when the board is essentially fully inserted in the connector. Otherwise, the switches are closed. The signal flow paths on the board are conductive when the board is both fully and partially inserted in the connector. When the board is partially inserted in the connector, both the by-pass and circuit board paths are conductive.