Abstract: A method and apparatus for a spherical parallel mechanism are disclosed. The invention involves a platform and at least three kinetic chains. The kinetic chains each comprise a link with one end pivotally coupled to the platform about a first axis and a second end pivotally coupled to an arm about a second axis. The arms in all of the kinetic chains share a common third axis. All of the first, second and third axes for all of the kinetic chains pass through a stationary point in space. Movement of the arms to selected angular positions about the common third axis adjusts an orientation and position of the platform about a spherical surface centered at the stationary point. The parallel mechanism has particular advantages for manipulating implements, such as cameras used in laparoscopic surgery, when the implements are mounted to the mobile platform.

Abstract: A support stand for surgical implements is disclosed. The support stand provides an operating environment which is particularly useful for use in laparoscopic surgery. The support stand is compact and includes positionable wrists for providing spherical motion of surgical implements about fixed points which can be made to coincide with incisions in a patient being operated on. Each wrist includes a member pivotally mounted to a support arm. Rotating the member provides rotation about a first axis passing through a fixed point. A surgical instrument holder is connected to the member by a linkage which provides rotation about a second axis passing through the fixed point. The linkage has four pivotally connected links, two of which are bent through an angle to provide precise spherical rotation about the fixed point.