Patent ID: 7580743

Claim:
A device for creating a cavity in a bony structure having at least two regions of different electrical impedances, said device comprising: means for penetrating into said bony structure having said at least two regions of different electrical impedance; means for monitoring said penetration of said penetrating means into said bony structure in real-time and for providing an operator with immediate information about passage of a tip of said penetrating means from a first of said regions into a second of said regions; said monitoring and information providing means comprising at least two electrodes and at least one impedance meter electrically connected to said at least two electrodes; at least one of said electrodes forming a distal end of said penetrating means and forming the tip of said penetrating means; said at least one impedance meter continuously receiving signals from the at least two electrodes at least during penetration of said penetrating means into said bony structure so as to continuously measure the impedance between the at least two electrodes during said penetration; said monitoring and information providing means further comprising at least one warning device connecting to said at least one impedance meter for receiving signals from the at least one impedance meter during the penetration of said penetrating means; and said at least one warning device having means for generating a warning signal when the tip of the penetrating means with said at least one electrode from said first of said regions having a first electrical impedance to said second of said regions having a second electrical impedance so as to enable the operator to immediately make any needed change in said penetration.