Intelligent Instrument Design
There is a pressing need for increasingly smaller medical devices as doctors seek to reduce the invasiveness of medical procedures. The challenge here is to reduce the size of instruments without sacrificing their dexterity. In the COMET Lab we tackle this challenge by creating continuum (that is, continuosly flexible) manipulator designs which can be miniaturized to create millimeter-scale robot arms.
One specific application we are currently looking at is endoscopy of the middle ear passing through the nose and the natural orifice of the Eustachian tube. This is a medical procedure that doctors have attempted unsuccessfully for years. The major roadblock is the lack of tip articulation in endoscopes < 2 mm (required to pass through the narrow lumen of the Eustachian tube), which greatly limits visual coverage once inside the ear. As an initial step towards solving this problem, we combined a state of the art miniature chip-tip camera and a new thin-walled asymmetric "slotted" tip design that can be controllably articulated. The video below shows how the endoscope would operate - the demonstration is carried inside a 3D printed model of the middle ear:
One of the main challenges of continuum manipulators is that the design space of these devices is infinite since they can assume nearly any smooth space curve (subject to material strain limit constraints). This makes finding task-specific optimal designs (e.g. designs that maximize visual coverage inside the ear) very difficult and brute-force searches not viable. We are exploring the use of intelligent optimization techniques (such as Evolutionary Algorithms) to tackle this problem.
L. Fichera, N.P. Dillon, D. Zhang, et al.
Robotics and Automation Letters 2(3):1488-1494, 2017.