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

Autonomous Magnetic Navigation Framework for Active Wireless Capsule Endoscopy Inspired by Conventional Colonoscopy Procedures

“…In this work, we consider a permanent magnet-based SMAL system to realize the autonomous navigation of the capsule. The magnetic actuation methods applied in existing permanent magnet-based SMAL systems for active WCE can be roughly classified into three categories: i) Dragging magnetic actuation (DMA), which directly uses the magnetic force generated by the magnetic actuator to drag or steer the capsule [4] [18] [19] [23]; ii) Continuously rotating magnetic actuation (CRMA), which uses a rotating magnetic field generated by a continuously rotating magnetic actuator for helical propulsion of a capsule with external thread in a tubular environment [13]- [15], [24]- [26], and iii) Reciprocally rotating magnetic actuation (RRMA), which uses a reciprocally rotating magnetic actuator to rotate a non-threaded capsule back and forth during propulsion in a tubular environment [27] [28]. Since the RRMA method [27] was introduced to reduce the risk of causing intestinal malrotation and enhance patient safety, and it was observed that the reciprocal motion of the capsule can help make the intestine stretch open to reduce the friction in narrow tubular environments compared with the DMA and CRMA methods, in this work, we apply the RRMA method in our autonomous magnetic navigation framework for safe and efficient actuation of the capsule.…”

“…The proposed autonomous navigation framework is implemented on a robotic system developed based on our previous work in [13], [15], [27] to allow closed-loop SMAL of a capsule. The design of the system is illustrated in Fig.…”

“…4(b), the center line of the magnetic ring embedded in the capsule coincides with the principal axis of the capsule. The 6-D poses of the capsule and the actuator can be represented by their positions p c , p a , unit magnetic moments m m m c , m m m a , and unit rotation axes (heading directions) ω ω ω c , ω ω ω a [15].…”

“…Subsequently, a sensor sub-array with the optimal layout is adaptively selected and activated from the entire sensor array based on the capsule's position to improve the localization accuracy and update frequency (line 3-4). Then, after the 5-D pose of the capsule (p c , m m m c ) is estimated using the MOT method (line 5), the heading direction of the capsule ω ω ω c is estimated using the normal vector fitting (NVF) method [15].…”

“…Previous studies have separately dealt with the above two tasks. Several SMAL systems have been developed to address the AP task based solely on the magnetic feedback [12]- [15] or on a fusion of magnetic and visual feedback [4]. While these methods can determine the real-time movement of the capsule based on the estimated direction of the intestine, the actual moving trajectory of the capsule cannot be precisely controlled to allow repeated inspections at given points (e.g., suspicious lesions) for high-quality diagnosis.…”