A microtome is an instrument used for cutting samples of organic tissue into thin sections for microscopic examination of the sections. The branch of science is called histology, and the cutting operation is performed by histotechnologists. In general, the subject tissue to be examined is encased in paraffin and clamped into place in the microtome. The sample is then either moved back and forth against the cutting edge of a microtome knife or the knife is drawn across the surface of the sample. The thickness of the section is dependent upon the particular purpose of the examination, and a very detailed study of delicate tissues may require a section with a thickness of only two millimeters, although five millimeter sections are more common. With such minute section thicknesses, and the critical nature of the studies performed by the histotechnologists, the cutting edge of the microtome knife must be extremely sharp. Knife edges which are not substantially perfect will result in tissue sections which are deformed or torn and, as a result, generally unsuitable for proper studies and diagnoses. Since every tissue sample is unique and a substitute sample may not be obtainable, the proper surgical precision must be maintained. The edges of the microtome knives must be frequently honed and deburred or stropped, the frequency dependent upon the nature of the tissue sample being sectioned, and the knives must occasionally be reground or reconditioned.
Due to the sharpness of the cutting edges required by the nature of the science, microtome knives are also very dangerous instruments which must be handled as little as possible and with the utmost care and respect. Currently, devices are available into which the knives are inserted, and in which the sharpening operation is performed automatically. These devices provide safety for the technician during the actual sharpening operation; however, the danger is still present during insertion and removal of the knife, the devices are very expensive to buy and maintain, and the sharpening operation may require an hour or longer. Thus, if sectioning bone samples, for example, which may require that the knife edge be honed several times a day, the sharpening or honing operation becomes a very costly procedure in terms of equipment and the technician's time, and in many cases, a costly knife inventory must be maintained.
A device which performs an instrument sharpening operation is disclosed in my U.S. Pat. No. 3,576,089, issued on Apr. 27, 1971, for a Honing and Sharpening Machine which uses a rapidly reciprocating hone for sharpening instruments and tools that are mainly used by dentists and surgeons. Another device used for polishing the cutting edge or tip of surgical instruments is disclosed in my pending application for a Polishing Machine for Cutting Instruments and Tools, Ser. No. 383,536, filed on June 1, 1982.
USPTO Backgrounds
USPTO Backgrounds