3-D force measurement using single axis force sensors in a new single port parallel kinematics surgical manipulator

Single port surgery is an innovative approach in the field of minimally invasive surgery. Although several telemanipulators exist to perform operations through only a single incision they all suffer from the lack of haptic feedback. To generate kinesthetic feedback the intracorporeal forces need to be measured, which is a challenging task. To overcome these limitations we investigate in this paper the force sensing capability of a new single port robot that has two parallelkinematic manipulators. Because of the rigidity and excellent controllability the tip force is measured using proximally arranged force sensors. To minimize friction effects a longitudinal vibration of 6 Hz with an amplitude of 20 µm is applied to the manipulator while the tip force is varied in the three main coordinate axes. Within the analysis 32320 values are investigated showing that a vibration has a significant impact and dramatically improves the signal quality by minimizing the crosstalk by a factor of up to 12.7 enabling to measure the tip force exactly.