Abstract: A data compression method utilizing a series of rules which are chosen for best compressing selected data. Rules are provided for converting each datum into a binary value, and encoding this binary value into a variable-width bit field. Rules are provided for automatically increasing or decreasing the binary field width which encodes the next data value, based on the current field width and encoded data value. An escape code is used to increase the field width for the next encoded value. A rule for efficient run-length encoding of repeated values or codes may also be included.

Abstract: A rotational adaptor is provided for use with a stereotaxic instrument used in brain research to hold and stabilize the head of a small animal, such as a rat, having a cradle with two ear bars and a nose clamp wherein the cradle may be rotated while maintaining support of the animal's head by the ear bars and the nose clamp. The device allows electrodes and micropipettes to be implanted through the side of the skull as well as through the top of the skull, increasing the number of available implant pathways and consequently reducing trauma experienced by the animal.

Abstract: A drill press is provided for use in conjunction with a three dimensional stereotaxic manipulator. The drill press includes a body carried by a movable member of the manipulator wherein the body has upper and lower segments and at least one guide shaft extending between the segments. A slide which carries a drill for forming skull openings is driven by a dial cord drive. The dial cord extends around a drive shaft so that rotation of the drive shaft by a handle causes the slide to move upwardly and downwardly to safely and quickly accomplish the formation of a skull opening in a small animal typically used in brain research.

Abstract: A pipette puller is provided for drawing glass or quartz tubing into micropipettes. A fixed clamp and movable clamp are utilized and between the clamps a furnace is provided which has an opposing pair of elongated heating elements. The heating elements are supported by binding posts of high thermal conductivity and relatively large mass, which provides relatively low thermal inertia of the heating elements.

Abstract: A means is provided for compensating for spherical aberration in charged particle beam devices. The means includes a sextupole positioned between two focusing lenses.

Abstract: A head positioner for radiologic and other medical procedures and a method for forming the head positioner are disclosed. A plastic rear component engages the backside of the patient's head, left and right plastic components engage each auditory meatus of the patient and a front component engages the nasion of the patient. Pressure is applied at the points of engagement and the components are secured to form a unitary headband structure. The headband is capable of repeated and periodic use in positioning the cranium of a human skull in precisely the same position relative to radiologic or other medical equipment. Apparatus for forming the headband structure is also disclosed.

Abstract: An improved ophthalmic instrument for removing vitreous and the like from the eye is provided having a smooth, unobstructed exterior surface for easy handling. The air pressure connection, vacuum connection and saline infusion connection are made through the end wall of the cap of the device.

Abstract: A pump is provided in which the fluid being pumped is used to lubricate the moving parts of the pump and the flow path of the fluid through the pump insures that at least a portion of the fluid circulates around the moving parts of the pump to assure efficient lubrication and rapid flushing of the pump. The pump is driven by a pair of concentric magnets, the interior magnet being sealed off relative to the outer magnet.