Design of steerable endoscopes to improve the visual perception of depth during laparoscopic surgery

Visual feedback during laparoscopic surgery is provided by an endoscope with a camera that is inserted through a small incision in the abdominal wall. The incision restricts the endoscope movements to 4 degrees of freedom (DOF), making it impossible to observe organs from different sides. This paper describes two 6 DOF steerable endoscopes that Contain a new spatial parallelogram-mechanism to transform the handgrip movements into movements of the steerable tip. Part of the mechanism is a new kind of spring that combines high torsion stiffness with a low bending stiffness. The endoscopes and the spring have been applied for two international patents.