A NEW DYNAMOMETRIC TECHNIQUE TO MEASURE AND LOCATE ENDOCRANIAL STRUCTURES - PRELIMINARY-REPORT

An apparatus for measuring and recording the resistance to penetration of endocranial tissue is described. The probe carrier, driven by a constant-speed electric motor, is fitted onto a stereotactic head frame which is used to guide the tool to the intended target. The displacement and resistance encountered when the tool penetrates intracranial structures are measured and recorded on an x-y recorder. Preliminary tests performed on calf brain specimens have documented that the apparatus can measure the different consistencies of normal cerebral tissue, and suggest a new technique for morphological investigations based on the mechanical consistency of normal and pathological organic tissue. Moreover, the hypothesis of a plastic deformation in cerberal tissue has been confirmed, in that the same apparatus permits measurement of the displacement of tissues caused by the advancement of the surgical tool. [Clinical implications for neurosurgery, e.g., tumor biopsy, are considered.].