Development of a Compact Autonomous Propeller-driven Capsule Robot for Noninvasive Gastric Endoscopic Examination

Wireless capsule endoscope ro!bot is painless, safe, and efficient throughout the inspection procedure, which offers a promising prospect in the early diagnosis of digestive tract diseases. In this article, we propose a compact design of capsule endoscope robot actuated by micro propellers for noninvasive gastric endoscopic examination. First, the shell structure, electronic components, and internal circuit board system of propeller-driven capsule endoscope robot (PCER) are designed to improve the mobility in liquid environment. The PCER is integrated with wireless communication module, microcontroller, camera module, motor driver chips, and battery. Then the undesired interference of four coreless motors with the embedded magnetic sensor in the PCER is avoided. The attitude calculation of the PCER is achieved by using the Kalman filtering algorithm based on inertial measurement unit and three-axis magnetic sensor. The PCER is controlled via the XBOX joystick, and the real-time attitude information can be obtained and displayed to ease the operation. The experimental results demonstrate the reliability and superior performance of the system. The PCER can perform the calculation of its own attitude, fixed-point rotation, upward spiral motion, and horizontal circular movement. The PCER reduces the dependence on external manipulation equipment and makes the application of capsule robot more convenient and adequate for different types of diagnoses and treatments in the stomach.