Improved Multiple Objects Tracking based Autonomous Simultaneous Magnetic Actuation & Localization for WCE

Wireless Capsule Endoscopy (WCE) has the advantage of reducing the invasiveness and pain of gastrointestinal examinations. In this work, we propose a system aimed at autonomously accelerating and locating the WCE inside the intestine for clinical applications. A rotating magnet controlled by a robotic arm is placed outside the patient's body to actuate the capsule with an internal magnetic ring, and the magnetic fields of the two sources are measured by an external sensor array. The original Multiple Objects Tracking method is improved by combining Normal Vector Fitting, Bézier Curve Gradient, and Spherical Linear Interpolation to estimate the 6-D pose of the WCE from a 5-D pose sequence. In order to close the actuation-localization loop, a strategy is presented to react to different states of the capsule. The proposed method is validated via experiments on phantoms as well as on animal intestines. The localization of the capsule shows an accuracy of 3. 5mm in position and 9. 4° in orientation, and the average update frequency of the estimated 6-D pose reaches 25Hz.

Authors

• Yangxin Xu
• Keyu Li
• Ziqi Zhao
• Max Q. -H. Meng

Keywords

• Magnetic moments
• Magnetic separation
• Object tracking
• Magnetic resonance imaging
• Interpolation
• Actuators
• Fitting
• Magnetic Actuation
• Multiple Object Tracking
• Wireless Capsule Endoscopy
• Simultaneous Actuator
• Magnetic Localization
• Magnetic Field
• Actuator
• Robotic Arm
• Bezier Curve
• Gradient Curve
• Synchronization
• Average Speed
• Control Points
• Magnetic Moment
• Plastic Tubes
• Rotation Axis
• Permanent Magnet
• Magnetic Force
• Pose Estimation
• Gradient Magnitude
• Capsule Size
• End Of Curve
• Straight Tube
• External Magnet
• Magnetic Torque
• Prototype Implementation
• Simultaneous Magnetic Actuation and Localization
• Multiple Objects Tracking