Abstract: An actuating mechanism for sequentially advancing and retracting a lancet needle includes a carriage for carrying the advancement and retraction of the needle, and a cam-following structure for transmitting propulsion to the carriage during the advancement. The actuating mechanism is also provided with a drive cam structure which engages the cam-following structure to direct the advancement propulsion. The cam-following structure can have a separate surface engagable with the drive cam structure during the retraction of the carriage and during arming of the actuator for the advancement propulsion.

Abstract: An apparatus is provided for making color comparisons between a test sample and a plurality of color samples. The color samples are arranged on a circle on a rotatable member and are successively moved into position adjacent a test sample. When an operator determines that a color sample adjacent the test sample is closest in color to the test sample he operates a switch which causes a stored numerical value associated with that sample to be read out and displayed on a display device.

Abstract: An apparatus is provided for making color comparisons between a test sample and a plurality of color samples. The color samples are arranged on a circle on a rotatable member and are successively moved into position adjacent a test sample. When an operator determines that a color sample adjacent the test sample is closest in color to the test sample he operates a switch which causes a stored numerical value associated with that sample to be read out and displayed on a display device.

Abstract: A surgical retractor is disclosed for use when surgery is performed adjacent a bone and remains in place for an appropriate duration without requiring manual assistance. A barrier member includes a plurality of cannulated fixation posts for its temporary placement on, and attached to, the bone and a soft tissue engaging surface which extends transverse of a surface of the bone. Guides, including the cannulated fixation posts, slidably receive mounting pins which supplement the fixation posts for temporarily attaching the barrier member to the bone. The barrier member is also provided with bottom and top flanges which extend transversely of the soft tissue engaging surface and cooperate therewith to prevent entry of the soft tissue into an adjacent surgical site.

Abstract: An improved acetabular cup for use in cement fixation has at least one flat area on its generally hemispherical outer surface. The flat area resists rotation of the cup in the cement mantle after implantation while avoiding concentrations of stress in the mantle.

Abstract: A circuit is described for applying a potential to an electrode of a biosensing test cell, which electrode, when properly inserted in a female connector, is contacted by a pair spaced apart contacts. The circuit includes a source of excitation potential and an operational amplifier having one input connected to the source of excitation potential. A switching circuit is coupled between the operational amplifier and a first one of the spaced apart contacts, with the switch means exhibiting an impedance. A feedback circuit is connected between the second of the spaced-apart contacts and another input to the operational amplifier, to feed back a potential appearing at the second contact. The feedback is for the purpose of maintaining the output of the operational amplifier at a level which compensates for impedance losses in the swtiching circuit.

Abstract: Improved resistance to linear displacement through bone is observed in a prosthetic patellar joint when the joint is attached to the patella by a protuberance which has a concave shape.

Abstract: A flexible enclosure is applied to a prosthetic joint to isolate wear particles which are produced by interengagement between the components of the joint. The enclosure overlies the joint, and is affixed to the respective joint components proximate to its ends. The enclosure may be impermeable to fluids and contain a synthetic synovial fluid for lubrication of the joint. Alternatively, the enclosure may be porous having pores of a size ranging between 0.1 and 100 microns across so as to maintain larger wear particles which the body cannot assimilate.