Towards a micropositioning system for targeted drug delivery in wireless capsule endoscopy

This paper describes a novel micropositioning mechanism for achieving 1ml of targeted drug delivery within wireless capsule endoscopes. The mechanism allows a needle to be positioned within a 22.5° segment of a cylindrical capsule and be extendible by up to 4mm. The mechanism achieves both these functions using only a single micromotor and occupying a volume of just 200mm³ (including micromotor), this represents only 6.6% of the total available space. Through a detailed stress analysis it has been shown that the proposed mechanism can be fabricated using FDA approved materials and requires a power budget of under 3.3% of the available capacity. It is envisaged this mechanism would empower a new breed of capsule microrobots for therapy in addition to diagnostics for pathologies such as ulcerative colitis and small intestinal Crohn's disease.