The advent of wireless capsule endoscopy is a milestone in the development of medical endoscopic tools. This chapter reviews and analyzes the key design techniques applied in current endoscopic capsules. This chapter also proposes the design of a Micro-Ball wireless endoscopic capsule with a wide field of view, which can fulfill the examination of the human gastrointestinal tract with low miss rate. The main design techniques applied in the Micro-Ball include master-slave architecture with a four-level clock management, a low-complexity image compressor, and a high-efficiency wireless power receiver chip.