Abstract

A laser delivery system comprises a light weight hollow boom having a bearing intermediate its ends which permits the distal end of the boom to move longitudinally and rotationally relative to the proximal end of the boom. The bearing supports the distal end without supporting physical contact, e.g. by a layer of fluid. The proximal end of the boom is carried by a boom support for movement about two axes, and includes a fork journalled in a base. In one embodiment, the shaft has a portion offset from the axis thereof, and a beam direction changer, such as a prism, is located along the shaft axis between spaced bearings journalling the shaft and carried by the base. In a second embodiment, a light conducting passage extends completely through the shaft. A handpiece is connected to the distal end of the boom for rotation about the boom axis. The boom is counterbalanced by a first counterweight in offset relation to the boom axis relative to the shaft axis, and on the opposite side from the boom of the pivotal axis transverse to the boom. A second smaller counterweight is between the boom support and the boom bearing, with its center of gravity on the boom axis, and a third counterweight smaller than the second is between the boom bearing and the handpiece, on the opposite side of the boom axis from the handpiece.