No abstract

Helical magnetic robots driven by an external magnetic field have been extensively studied for robotic endovascular intervention to treat occlusive vascular disease. Most previous researchers have utilized cone-shaped head helical magnetic robots (CHMRs) with helical blades for thrombus drilling. However, the CHMR may become stuck in the thrombus or drilling performance may be significantly reduced after the cone-shape head enters the thrombus. We propose a sawtooth head helical magnetic robot (SHMR) to improve drilling performance. Furthermore, the pitch length of the SHMR was optimized experimentally. Finally, improved drilling performance of the SHMR compared to CHMR was verified by in vitro drilling experiments with a pseudo thrombus containing 0.8 wt. %, 1.0 wt. %, and 1.2 wt. % agar.

No abstract

We developed a resonance control method to generate a high-speed rotating magnetic field in a three-phase magnetic navigation system composed of three electromagnets. The proposed resonance control method calculates the amplitudes and phases of voltages, while the capacitances suppressing the self and mutual inductances of the electromagnets to keep the currents and the magnitude of the rotating magnetic field constant, even if the frequency of the rotating magnetic field increases. Finally, we prototyped the three-phase magnetic navigation system and the variable capacitor module to validate the effectiveness of the proposed resonance control method experimentally.