Patent ID: 8348861

Claim:
A system for the insertion of a needle having a tip into a tissue, according to a predetermined trajectory, comprising: a robot for maneuvering said needle into said tissue; an imaging system for ascertaining the trajectory of said needle in real time; and a control system controlling said robot motion according to differences between said ascertained trajectory and said predetermined trajectory, wherein said controller utilizes a model of said needle as a flexible beam having a plurality of virtual springs each having a coefficient of stiffness connected laterally thereto to simulate lateral forces exerted by said tissue on said needle, and whose trajectory through said tissue is determined by the influence of said plurality of virtual springs on said needle, and wherein said system determines the needle trajectory taking into account the change in the stiffness coefficients of at least some of said virtual springs as a result of the trajectory of said needle and said control system utilizes an inverse kinematics solution applied to said virtual springs model to calculate the required motion to be imparted to said needle to follow said planned trajectory.