Patent ID: 9345487
Filing Date: 2016-05-24
CPC Classification: A61B

Claim Text:
1. A method of drilling through bone comprising the steps of: (i) providing a drilling device having an electrically conductive bone cutter and an electrically conducting nosepiece assembly spaced from the conductive bone cutter, and acting as a counter electrode; (ii) placing the conductive bone cutter and nosepiece assembly into contact with the bone tissue to be drilled; and (iii) commencing the drilling of the bone tissue; said drilling device further comprising: (a) a housing that includes a drilling assembly and an electrically conductive nosepiece assembly to be placed in contact with bone tissue to be drilled; (b) a bone cutter rotated by an electric motor which is mobile in translation in the housing and wherein the bone cutter is electrically conductive and is adapted to be moved into and out of the bone tissue being drilled; (c) a printed circuit board control module electrically connected to the drilling assembly for controlling the translation of the bone cutter in the housing and into and out of the bone tissue being drilled; (d) a sensor, electrically connected to the drilling assembly and to the control module, for detecting a change in an electrical impedance between the bone cutter and the surface of the bone tissue being drilled; wherein upon detection, by the sensor, of a change in the electrical impedance corresponding to a transition between air (no load; high electrical impedance) and bone tissue surface, sends a signal to the control module begins incrementing a step counter; and (e) wherein the direction of the vertical drive motor is automatically reversed when the step counter reaches a prespecified count, thereby withdrawing the bone cutter from the bone tissue being drilled, and thereby controlling the depth of the drilled hole.