Abstract: Disclosed is a system for percutaneously steering a surgical needle. Needle steering is accomplished by taking advantage of a deflection force imparted on the bevel tip of the needle by the tissue medium as the needle is pushed through the tissue. By controlling the translation speed and rotation angle of the bevel, a flexible needle may be steered substantially without deflecting or distorting the tissue. The control inputs (translation speed and rotation angle) are computed based on a “bicycle” non-holonomic kinematic model that is a function of mechanical properties of the tissue medium. The system may be used with image-based feedback, which may provide for feedback-based refinement of the model as the needle propagates through the tissue.

Abstract: Disclosed is a transcavital needle insertion device that incorporates a transrectal ultrasound (TRUS) probe; a support sheath incorporated with, but mechanically decoupled from the TRUS probe to substantially stabilize the target tissue being imaged; and a needle guide sheath that moves relative to the TRUS probe. The device substantially enables a practitioner to more accurately and precisely insert a therapeutic needle into a target tissue, such as a prostate, in a decoupled three degree of freedom coordinate space that is registered to the imagery generated from the TRUS probe. The support sheath may enable the practitioner to move the TRUS probe, and independently position and insert the needle, without problems brought about by variable deformation of the target tissue, which would otherwise result from motion of the TRUS probe and the needle.