Feasibility study on magnetically steerable guidewire device for percutaneous coronary intervention

In this paper, we proposed a magnetically steerable guidewire device composed of two parts: steering part and feeding part. The steering part consists of a magnet attached to the end of a commercial guidewire and 2-pair Helmholtz coils, and the feeding part consists of a motorized stage and a device for holding the guidewire. In detail, the 2-pair Helmholtz coils generate a uniform magnetic field that can align the guidewire magnet in the region of interest (ROI) along a desired direction. In addition, the feeding part remotely controls guidewire insertion and the length of the flexible part of the guidewire extruded from a catheter. For accurate alignment at the end of the guidewire, we controlled the flexible length of the guidewire extruded from a catheter and the intensity and direction of the uniform magnetic field using the feed-forward method. In addition, to reduce alignment error due to unpredicted disturbances and friction effects between the test-bed and the guidewire, proportional-integralderivative control is introduced as a feedback control algorithm. Using the control algorithms, we demonstrated accurate actuation of the steerable guidewire device with a steering angle error of less than 0:5◦. We expect that the proposed steerable guidewire device can be applied to the development of a 3-D locomotive guidewire with position recognition for percutaneous coronary intervention (PCI).