Patent ID: 8496647

Claim:
An apparatus, comprising: a wrist joint; a surgical end effector coupled to the wrist joint; a shaft including a distal end; and a force sensor coupled to the distal end of the shaft, wherein the force sensor comprises a tube portion including an outer surface, a plurality of ribs, and a plurality of strain gauges, wherein the tube portion comprises a proximal end, a distal end, and a lengthwise axis that extends between the proximal and distal ends of the tube portion, wherein the proximal end of the tube portion is coupled to the distal end of the shaft, and wherein the distal end of the tube portion is coupled to the wrist joint; wherein the plurality of radial ribs are inside the tube portion, wherein each radial rib of the plurality of ribs extends lengthwise in the direction of the lengthwise axis and extends radially outward along a radius of the tube portion to the tube portion; and wherein each of the plurality of strain gauges is at the outer surface of the tube portion and is positioned and aligned lengthwise with a corresponding one of the plurality of radial ribs.