Apparatus and method for calibrating a surgical knife

A system that can be used by a viewer to calibrate a surgical knife, comprising;

• a surgical knife that has a body and a blade with a tip that can move relative to a foot plate;
• sensing means for sensing the position of said tip relative to said body and providing an output signal thereof;
• visual display means coupled to said sensing means for receiving said output signal and providing a visual readout of the position of said blade tip relative to said body, the visual display further having input means to allow the viewer to manually set a zero on the visual readout;
• and,
• a calibration housing which has a holder and a first sleeve, said calibration housing having an inner cavity that can receive said blade and at least a portion of said body, said first sleeve having a first marking and at least a segment which is transparent so that the viewer can view said first marking and said tip of said blade when said surgical knife is inserted into said calibration housing, said sleeve further having an aligning surface which engages the knife and aligns the foot plate with said first marking.

A system that can be used by a viewer to calibrate a surgical knife, comprising;

• a surgical knife that has a body and a blade with a tip that can move relative to a foot plate;
• sensing means for sensing the position of said tip relative to said body and providing an output signal thereof;
• visual display means coupled to said sensing means for receiving said output signal and providing a visual readout of the position of said blade tip relative to said body, the visual display further having input means to allow the viewer to manually set a zero on the visual readout;
• a calibration housing which has a holder and a first sleeve, said calibration housing having an inner cavity that can receive said blade and at least a portion of said body, said first sleeve having a first marking and at least a segment which is transparent so that the viewer can view said first marking and said tip of said blade when said surgical knife is inserted into said inner cavity, said sleeve further having an aligning surface which engages the knife and aligns the foot plate with said first marking;
• a microscope that magnifies said first sleeve, said microscope having at least one eyepiece that allows the viewer to view said blade tip and said sleeve;
• and,
• an arm attached to said calibration housing and connected to said microscope so that the viewer can move said first sleeve under said microscope.

A method for zeroing a surgical knife that has a blade tip which can move relative to a footplate, the surgical knife being coupled to a visual display by sensor means which detect the position of the blade tip relative to the footplate and provide an output signal that is received by the visual display and converted into a visual readout that provides a viewer an indication of the relative position of the blade tip and the footplate, the visual display further having input means for allowing the viewer to zero the visual display, comprising the steps of;

• a) inserting the surgical knife into a calibration housing which has a sleeve that has a first marking, said surgical knife being inserted until the footplate is parallel with said first marking, said calibration housing being coupled to an optical system that magnifies said sleeve so that the viewer can see the footplate, the blade tip and said first marking;
• b) moving the blade tip until the blade tip is parallel to said first marking;
• and,
• c) inputting a zero into the visual display.