胶囊内镜是一种新型的消化道检查手段，目前对胶囊内镜的跟踪定位技术仍存在动态精度低和磁干扰下跟踪失败等问题。提出了一种基于粒子滤波(PF)的磁定位方法，相比于传统的定位方法，PF方法能保证胶囊在移动过程中仍有较高的定位精度，并且能够克服铁磁性物质或通电线圈对磁场环境的影响。在设计的PF算法中添加了对目标运动的估计和对磁干扰的估计：前者用于补偿时序采样下不实时的磁场测量值，后者用于补偿磁干扰。实验结果表明，在有限的磁干扰影响下(＜1.5 μT)，传统的定位方法已无法正常跟踪，而本方法的动态定位的平均误差能保持在6 mm以下，能够满足临床应用的要求。

Capsule endoscopy is a new examination method of gastrointestinal tract. The tracking and localization technique of capsule endoscopy still have the problems of poor dynamic accuracy and tracking failure under magnetic disturbance. This paper proposes a magnetic localization method based on particle filter (PF). Compared with traditional localization method, the proposed PF method can effectively avoid the poor accuracy in the dynamic tracking, and overcome high sensitivity to magnetic disturbance generated by the ferromagnetic materials or surrounding electrical currents. The estimation of the target movement and the estimation of the magnetic disturbance are added in the designed PF algorithm. The estimation of the target movement is applied to compensate measured value of magnetic field when the measurement under time sequence sampling isn′t real time. The estimation of the magnetic disturbance can compensate the magnetic disturbance. The experimental results show that, under limited magnetic disturbance (＜1.5 μT), traditional localization method cannot work. For the dynamic localization, the averaged error of the proposed method is less than 6 mm, which meets the requirements of the clinical application.