Patent ID: 6663588
Filing Date: 2003-12-16
Classification: A61M

Abstract:
A handle assembly for use in an instrument having bidirectional steering and a deflectable shaft, wherein upon being deflected in a first direction, the shaft generates a return force in an opposite second direction, and the shaft whereupon being deflected in the second direction generates a return force in the opposite first direction, the assembly comprising:a manually positionable control mechanism coupled to the shaft to selectively deflect the shaft in the first and second directions; and a counterforce mechanism operably coupled to the control mechanism and arranged to actively reduce a deflection force needed to continue to deflect the shaft in one of the first and second directions, the counterforce mechanism applying a biasing force to the control mechanism in a direction opposite to the return force once the control mechanism is moved from a neutral position in which the shaft is in a straightened position, the biasing force being about equal to the return force so that the forces effectively offset one another and permit a user to more easily and progressively deflect the shaft.