胶囊内窥镜位置方向磁场定位技术的研究

On the Magnetic Localization Techniques for Position and Orientation of the Capsule Endoscope

胶囊内窥镜是极有潜力的新型肠胃道检查手段,但是目前的临床胶囊内窥镜产品还存在一些问题需要解决,其准确定位跟踪是关键之一。在各种可能的定位方法中,利用磁体的定位技术具有明显的优势:无需供电、占用胶囊空间小、可以连续跟踪、实时性强和无副作用。本文重点讨论基于磁场传感器阵列实现对胶囊中磁体进行定位的方法,通过算法和系统的优化设计,实现了以磁偶极子为数学模型的3维位置和2维方向实时定位跟踪。为了消除人体运动对胶囊跟踪的干扰影响,本文提出对胶囊和参考目标磁体同时定位的方法,也提出了对胶囊的3维位置和3维方向的全6维定位算法以开展三维重建和病变组织的准确测算。实验结果证明本系统可对胶囊内窥镜实现2～3mm精度的定位跟踪。

Wireless Capsule Endoscope(WCE) is a very promising tool for the examination of the gastrointestinal(GI) tract.However,there are some problems to be solved for the existed WCE,and one key problem is the accurate localization and tracking of the WCE.Among the possible localization methods,the magnet-based localization technique has its advantages:no need for power,not much space occupation,continuously tracking ability,and no negative effect.In this paper,we present the localization method for the magnet objective inside the WCE based on the magnetic sensor array outside the human body.Through the algorithm and system design we realize real time tracking of 3D position and 2D orientation of the magnet based on the magnetic dipole model.In order to overcome the interference of the human body movement,we propose the multi-magnets' localization method;also,the 3D positioning and 3D orientation method is proposed,which can be used to make the 3D recovery of the GI tract and the accurate computation of the physiological tissue parameters.The real experiments show that the proposed localization system can run well and obtain the accuracy with 2～3mm for the magnet.