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We have proposed a magnetic motion capture system using an LC resonant magnetic marker. The proposed system is composed of an exciting coil, an LC marker, and a 5×5-matrix search coil array (25 search coils). The LC marker is small and has a minimal circuit with no battery and can be driven wirelessly by the action of electromagnetic induction. It consists of a Ni–Zn ferrite core (3 mm[lowercase_phi_synonym]×10 mm) with a wound coil and a chip capacitor, forming an LC series circuit with a resonant frequency of 186 kHz. The relative position accuracy of the system is less than 1 mm within the area of 100 mm3 up to 150 mm from the search coil array. Compared with dc magnetic systems, the proposed system is applicable for precision motion capture in optically isolated spaces without magnetic shielding because the system is not greatly influenced by earth field noise. [ABSTRACT FROM AUTHOR]

By the sterolithography technique and the ferrite plating, we fabricated three types of magnetic micromachines which coated Fe[SUB3]O[SUB4], Co[SUB0.39]Fe[SUB2.61]O[SUB4], and Co[SUB0.45]Fe[SUB2.55]O[SUB4], respectively. The stereolithography technique enables one to form the spiral-shape resinous templates and the ferrite plating enables one to coat the ferrites uniformly onto these templates from an aqueous solution. The total machine weight is light because a resin of the template body is almost the same density as water. We verified that the machines swim freely and wirelessly in water by applying a rotational magnetic field. As these machines coated with ferrites have the biocompatibility, there is the possibility of medical microrobots which swim in the human body for medical operations. [ABSTRACT FROM AUTHOR]

We have developed a jaw tracking system with wireless resonated markers. The system consists of two resonated markers, driving coil, 40 pickup coils, DA converter, and AD converters. The two resonated markers were composed of a coil with NiZn ferrite and tip condenser. We attached to one marker on the incisor and the other on the forehead. Position accuracy of within 1 mm was achieved when the fabricated jaw model was moved about 40 mm. This system is available for tracking of reasonable jaw movement of normal subjects without disturbing the physiology. [ABSTRACT FROM AUTHOR]