The kinematic synthesis of a spatial, hyper-redundant system based on binary electromagnetic actuators

Flexible endoscopes are a common instrument for different tasks in minimally invasive surgery. The motion and capability of resistance against manipulation forces of common endoscopes is restricted due to their flexibility. They tend to form loops and stress their surroundings. This paper proposes an active shaft concept based on a new actuation concept: the shaft is a hyper-redundant snake-like robot with binary electromagnetic actuators. This system combines good path following capabilities through actively controlling the whole endoscope body with good resistance with respect to manipulation forces through electromagnetism. The functional concept is presented and the influence of design parameters on kinematic characteristics such as workspace and radius of curvature is evaluated. Additionally, a set of kinematic design parameters is synthesized by minimizing the contouring error. Therefore, a path fitting algorithm is proposed.