Abstract: An instrument for automating corneal surgical procedures, such as radial keratotomy and other corneal operations, which includes one or more probe sensors with extendible tips which, by measuring electrical resistivity, are responsive to contact occurring with the corneal surface. Positioning of the probe sensor(s) over various points of the corneal surface provides data signals which enable the surface topography of the cornea to be mapped by a micro-processor. A surgical knife having automatic depth control is provided whose operation is regulated in response to changes in the electrical resistivity between the knife and the human body as penetration is made into the layers of the cornea. The probe sensor(s) and knife are used with a ring-like fixture attachable by vacuum to the eye and comprised of a fixed outer ring and a movable inner ring, the fixture providing mounting and/or support for these elements while permitting their movement to different meridial locations by rotation of the inner ring.

Abstract: A programmable thermostat has an associated electronic control circuit. There is a coding matrix and a multiplicity of programs which may be selected via the matrix. The user may select two set points to cause two programs to work in an interrelated manner, one for high heat requirements and one for low heat requirements. A clock may call in the two programs in any pre-selected manner such as: high heat in the morning, low heat as soon as the house has heated, high heat in the evening when the outside temperature falls, and low heat at night.