Patent ID: 7500853

Claim:
An apparatus, comprising a base; a first extension member having a first end and a second opposed end, the second end coupled to the base, the first extension member pivotable about a first axis; a second extension member having a first end and a second opposed end, the second end coupled to the base, the second extension member pivotable about a second axis, wherein the first axis and second axis intersect; a first central member having a first end and a second opposed end, wherein the second end is pivotably coupled to the first end of the first extension member; a second central member having a first end and a second opposed end, wherein the second end is pivotably coupled to the first end of the second extension member, the first end of the first central member and the first end of the second central member converge toward one another at an interface region to form a closed loop, the interface region adapted to receive a removable user graspable object, wherein the user graspable object is moveable with respect to the base; a sensor configured to measure position of the user graspable object, the sensor configured to provide at least one sensor signal associated with the position of the user graspable object to a processor; and an actuator coupled to a portion of the linkage and configured to output a force to one or more of the members based on the an activating signal received from the processor, wherein the activating signal is based at least partially on the sensor signal.