an articulated surgical instrument for enhancing the performance of minimally invasive surgical procedures . the instrument has a high degree of dexterity , low friction , low inertia and good force reflection . a unique cable and pulley drive system operates to reduce friction and enhance force reflection . a unique wrist mechanism operates to enhance surgical dexterity compared to standard laparoscopic instruments . the system is optimized to reduce the number of actuators required and thus produce a fully functional articulated surgical instrument of minimum size .