Fringe Field Navigation for Physiological Parametric Measurements in Deep Tissues

Abstract

Probing hard-to-reach physiological locations such as the ones accessible through vascular vessels can be challenging. This could be achieved by recording physiological parameters from a sensor placed at the tip of a catheter or using simple electrical wires linking the sensor to an external piece of equipment. The latter would result in smaller diameter implementations capable of reaching deeper locations by navigating though narrower blood vessels or other physiological routes. But unlike in the case of a catheter or similar instruments, the very low stiffness of the connecting wires would prevent the possibility of pushing the sensors deeper in the physiological spaces. Therefore, a directional pulling force would be required. This directional pulling force can be provided by a method developed by our group and dubbed fringe field navigation (FFN). In a clinical setting, the external magnetic field surrounding a clinical magnetic resonance imaging (MRI) scanner provides such pulling force from the high magnetic gradient field exceeding 2T/m. The direction of the force is changed by moving a robotic table near the scanner.