Patent ID: 8167897

Claim:
A multimode instrument assembly for standardizing a dermatotomy procedure having a longitudinal axis, a front end and a back end comprising: an instrument holder extending along the longitudinal axis having an instrument holding portion disposed at the front end, a back shaft portion disposed at the back end, and a front shaft portion extending between the instrument holding portion and the back shaft portion; a blade fixedly attached to the instrument holding portion; a hollow sheath body comprising an annular wall surrounding a second longitudinal cavity for encapsulating the blade therein and for interfacing with the front shaft portion to movably support the hollow sheath body for longitudinal translation with respect to the front shaft portion and the blade; a handle actuator comprising an annular wall surrounding a first longitudinal cavity for movably receiving the hollow sheath body therein and for interfacing with the back shaft portion to support the handle actuator with respect to the back shaft portion and the hollow sheath body; said hollow sheath body being movable between multiple positions including a piercing position for making a predetermined accurate pierce cut in a patient, further including means disposed in said hollow sheath body and said handle actuator for exposing said blade a constant piercing length, depth, and location at the front end; said hollow sheath body extending distally along opposed side walls that terminate in a front face of the hollow sheath body that is for resting on the surface of a surgical patient, said front face extending substantially transverse to the longitudinal axis of the instrument assembly, said front face having an aperture therein through which the blade extends in the piercing position thereof; and said front end including at least one guide wire receiving groove for receiving therein a guide wire, said groove being an indentation extending into and along a first side wall of the opposed side walls of said hollow sheath body, said groove having a predetermined depth therealong and extending continuously from a location along the longitudinal axis that is proximal to the end face to terminate at the end face, the depth of said groove being positioned a predetermined distance away from said aperture in said front face to provide for forming a bridge between the aperture and the groove.