本文亮点在于，提出了基于旋转磁场的对胶囊的驱动定位方式。主要阐述了在旋转磁场下，定位与驱动交替的方式。在step-out情况下，驱动失效，定位胶囊；在synchronous情况下，驱动有效，胶囊跟随主动磁铁同步旋转。这是一种定位时看起来驱动没有停止，而驱动和定位实质上分离（解耦）的同时驱动和定位方式。
使用一个固定式旋转磁极子场的一个磁胶囊内窥镜的6自由度定位
6-D localization of a magnetic capsule endoscope using a stationary rotating magnetic dipole field [1]
Paper Link
Authors: K. M. Popek, etc.
2015，Hamlyn Symposium on Medical Robotics
获得的精度对于我们先前发表的磁驱动理论的使用可能是满足的。它与其他6自由度定位理论相比表现得不差；在一个略小于15厘米的球面内有5毫米的平均误差。这个定位理论不能够定位一个同步旋转的胶囊因为这个假设，胶囊没有净运动。但是，一个简单的控制方案涉及在周期性的间隔中暂定驱动，增加极子场的转速或者绕一个正交轴旋转它，其中的任一个将导致胶囊停止同步旋转，在收集一些旋转的数据后，继续以期望的方式驱动胶囊。外部极子源没有必要有其他的运动。对于所报告的实验，我们任意选择使用关于三个正交轴的两个旋转。更进一步的调查需要被进行来确定采集数据的数量与结果精度之间的关系。
The accuracy obtained is likely to be sufficient for use with our previously published magnetic actuation method. It performs comparable to other 6-D localization methods; has an average error of 5 mm in a sightly smaller 15 cm sphere. This localization method is not capable of locating a synchronously rotating capsule because of the assumption that the capsule has no net motion. However, a simple control scheme involves pausing actuation at periodic intervals, and either increasing the rotating speed of the dipole field or rotating it around an orthogonal axis, either of which will cause the capsule to stop rotating synchronously, and after collecting a few rotations of data, continue propelling the capsule in a desired manner. No additional movement of the external dipole source is necessary. For the reported experiments, we arbitrarily chose to use two rotations about three orthogonal axes. Further investigation needs to be done to determine the relationship between the amount of data collected and the resulting accuracy.
[1]: Popek, K. M., and J. J. Abbott. “6-d localization of a magnetic capsule endoscope using a stationary rotating magnetic dipole field.” Hamlyn Symposium on Medical Robotics. 2015.