Axially Distributed Fluidic Actuators for Steerable Minimally Invasive Surgical Device Applications

Inhalt:
Recent advancements in the design of miniature fluidic actuators have enabled the development of novel actuation schemes suitable for use in a wide range of minimally invasive surgery (MIS) applications. Due to their high force production, high bandwidth, and potential for miniaturization, research has been ongoing to integrate fluidic muscles in steerable catheters. In previous work, intrinsically actuated steerable surgical catheters have been built using an arrangement of 2−4 fluidic artificial muscles antagonistically connected in parallel within a bending segment at or near the distal tip of the catheter. This configuration necessitates a larger catheter diameter to accommodate the actuators without any interference between the pressurized actuators or catheter interior walls. In this study a novel design is presented which distributes actuators along the length of the catheter to ensure that only one actuator takes up cross sectional space at any point along the device. This enables significant reduction in diameter with comparison to the state-of-the-art. A proof of concept prototype has been built using 2.0 mm diameter pneumatic artificial muscles to actuate a 3.3 mm diameter steerable catheter bending segment beyond a +/−90 deg range of motion in a tortuously constrained space.