The present invention appropriately determines a point of time when a pressurization member such as a pump roller starts squeezing an elastic tube, that is, a point of time when a tube pump starts to generate pressure. The combiner 5 has a contour which can be visually recognized from the eye point and nearly surrounds the virtual image and a real image of the meter units 9, 9. The back portion comprises an outer frame having a hollow insert and a cloth backing adapted to support a patient’s back; the head support portion comprises an inner frame adapted to be received in the hollow insert of the outer frame. The end effector moves the offset tool to the offset target and docks them.