Quasi-static modeling of the da Vinci instrument

Two simplified quasi-static models for the da Vinci instrument are proposed which take into account distributed frictions and compliance of the tendons. These models are derived from static analysis of the interaction of the tendons with a curved surface. The key parameters of the models are identified, and the performance of the models is experimentally evaluated. Experimental results obtained suggest that a weighted combination of the outputs of the two models provides a sufficiently close estimate of the output torque of the da Vinci instrument.