Voice Coil Navigation Sensor for Flexible Silicone Intubation

This paper presents a novel navigation sensor for guidance of a flexible tube based on magnetic induction. In many applications, such as pipe inspection and medical intubation, the flexible tube has been utilized for inner surface monitoring and inspection. In particular, for medical intubation that inserts a stomach tube or endoscope, accuracy of locating the flexible tube mainly relies on experienced operators. Although X-ray tomography and oxygen sensors have been applied to detect the location of the inserted tube, the implementation is usually time consuming and costly, an equipment being bulky so that their practical applications are limited. On the contrary, magnetic sensors, offering contact free and compactness in size, have been preferred in the areas of position/orientation detection. In this study, a compact orientation sensor based on magnetic induction has been developed; both magnetic field generator and detector are designed to minimize the space along the flexible tube. Magnetic mutual inductance is analyzed with the extended-distributed multiple-pole model, and design parameters are optimized to determine an operating range of orientation angles. Performance of the sensor is numerically simulated and compared to experimental results. The results show the accuracy in a wide operating range and the potential in many applications.