Method for transmitting torque and variably flexing a corrugated insertion device

A method for transmitting torque and variably flexing an insertion device for receiving an instrument, the method comprising the following steps:

• providing a hollow body;
• transmitting torque along the hollow body with a corrugated tube;
• applying suction to create a vacuum in the hollow body for placing the hollow body in a relatively stiff condition;
• relieving the vacuum for placing the hollow body in a relatively flexible condition;
• maintaining the hollow body in the relatively flexible and relatively stiff conditions with tendons disposed within the hollow body, the vacuum created by the applied suction frictionally locking the tendons and the corrugated tube in place in the relatively stiff condition;
• and
• individually adjusting at least some of the tendons in length for steering a distal end of the hollow body.