Abstract
We have developed the probe scan mechanism for echography using pneumatic actuators. First we established a driving system of the actuator by driving an electro-pneumatic control valve to examine the relationship between force and pressure. Then we constructed the mechanism to be put on patient abdomen by arranging six actuators around the probe to realize five degrees of freedom including the press motion of the probe. Total weight of the mechanism could be set less than 700[g]. Next we established feedback control method of both of position and pressure in the probe. Because the contact force on body surface cannot be measured directly, we have applied an estimation control in contact force from inner pressures of actuators to realize maximum error of 25% in the contact force.
