Abstract: Tow forces can be measured only by providing one force sensor in a device structure, and a drive system is driven so as to assist an external force by detecting it. A value at a force sensor (114) at the moment when a foot switch (121) is set as the original point (detection reference) of a force to be assisted. Variations of the force after the original point setting is measured by the force sensor (114) the difference between the measured value and the assist original point is obtained, and a force to be assisted is detected. Depending on the magnitude of the force to be assisted, assist operation is performed by causing a drive force to act on a foot such that the force to be assisted is reduced. When the force is assisted reaches zero, the assist operation is completed. Then, two forces, or “a force acting on a patient's foot” and “a force applied to the foot” from the outside, are detected by the one force sensor (114).

Abstract: A bending forceps 1 has at least three degrees of freedom including relative opening/closing of a pair of gripping members 11a, 11b, rotation of both the gripping members around a first axis 15 and rotation of both the gripping members around a second axis 42 existing on an imaginary plane substantially perpendicular to the first axis 15. A drive power from an actuator is converted to each motion of the opening/closing of the gripping members, rotation thereof around the first axis and rotation thereof around the second axis by first to third link mechanisms 5, 6 and 7. The present invention enables the durability and control accuracy to be raised by employing a link mechanism as a drive power transmitting means. Further, the present invention facilitates sterilization, cleaning and attachment/detachment to/from a driving means.