Patent ID: 8016786

Claim:
A method for deploying a tool in a body lumen, said method comprising: introducing the tool into the body lumen; inflating an actuator to advance the tool within the body lumen, wherein the actuator is inflated to a pressure below a threshold pressure to advance the tool by a fixed distance determined by a flexible but relatively non-distensible section of the actuator; and inflating the actuator to further advance the tool within the body lumen, wherein the actuator is inflated to a pressure above the threshold pressure to allow expansion of an elastomeric region of the actuator which was not significantly inflated at pressures below the threshold pressure; wherein inflating the actuator to the pressure opens an involuted section of the actuator to advance the tool by said fixed distance; wherein the involuted section is formed from a non-distensible material which limits the distance the needle can travel.