用于体内胶囊式遥测系统的电磁跟踪定位方法

Electro-magnetic tracking system for capsule-typed telemetric device

提出了基于电磁检测原理的定位方法。该方法在体表布置多个电磁发射线圈,通过胶囊内密封的接收线圈检测所在点的磁感应强度,利用检测值,根据磁感应强度和该点位置坐标之间的函数模型反向求解出位置信息。设计的悬浮式单维接收线圈,能始终保持接收方向的恒定,不仅大大减少了接收线圈和发射线圈维数,也大大降低了求解模型的复杂性,满足了胶囊内严格的空间限制和功耗限制。设计了完整的电磁定位系统,构建了三维实验平台,并开展了38个位置点处的检测,将结果代入定位软件求解后表明,三个坐标方向的定位误差均在4 cm以下,平均定位误差在2 cm以下,小于同类研究的定位误差。

An electro-magnetic tracking method was proposed. Putting several circular current loops on body surface, a well-designed receiving coil in the capsule can always keep its orientation. Through detecting the magnetic field strength by a receiving coil, and deducing the functional relationship between the position parameters of the coil and the magnetic field strength, the position of the capsule can be determined. This design not only simplifies the structure of the whole system compared with a common one, but also makes the arithmetic easy for ensuring its feasibility in application of capsule positioning. The transmitting and receiving system and a three-coordinate experimental device were constructed. A test including 38 points was carried out to verify the method and the system. The result shows that the maxim positioning errors of x, y, z coordinates are less than 4 cm, while the mean errors are less than 2 cm, which is better than current precision of other positioning methods for the capsule-typed device.