设计了基于三轴磁感传感器阵列的体内微型诊疗胶囊定位跟踪系统,分析了系统的主要误差来源,提出了对背景磁场干扰、传感器灵敏度差异、传感器位置偏差、三轴传感器模块的非理想正交等误差的补偿和修正方法,并进行了定位实验和轨迹跟踪实验以检验误差修正效果。实验结果表明:误差修正后系统的定位与定向精度得到显著提高,对于距离传感器阵列平面150mm的Ф8mm×8mm的圆柱形N35铷铁硼永磁体,平均定位与精度达到8mm以内,平均定向精度达到6°以内,并能够对沿模拟肠道运动的内置永磁体的电子胶囊进行轨迹跟踪。
A 3-axis magnetic inductive sensor array system used for localization and tracking of micro diagnosis capsule in human gastrointestinal tract is designed, error sources of this tacking system are analyzed, and the error correction methods are proposed to obtain better accuracy. The correction methods include background magnetic field elimination, sensitivity calibration, sensor position correction and sensor orthonormality adjustment. The experiment results show that the error correction procedure can improve the localization accuracy prominently. For the Ф8 mm ×8 mm cylindrical N35 NdFeB magnet,the average position error is less than 8 ram, and orientation error is less than 6°when the magnet is 150 mm above the sensor array plane after the error correction procedure is implemented. The localization system can also track the locus of the capsule with a magnet inside, when it moves among the simulative intestinal tract.