Tomohiro Ota

Noninvasive blood glucose assay using a newly developed near-infrared system

This paper reports in vivo near-infrared (NIR) noninvasive blood glucose assay using dermis tissue spectra. We assume that the glucose content in dermis tissue traces the variations in blood glucose. For dermis spectra measurements, epidermis, especially stratum corneum, acts as an interference in skin tissue. Thus, we have developed a method for the selective measurement of dermis tissue spectra, enabling us to obtain better quality spectra for an accurate blood glucose assay. The selective measurement of the dermis spectra realized by using a newly developed fiber-optic probe that consists of source and detector optical fibers separated by 0.65 mm on a skin surface. The light path in the skin tissue for this geometry has been simulated by a Monte Carlo method. The simulation results show that detected light mainly interrogates dermis tissue. As the absorbance signal of glucose in human tissue is extremely small, the quality of the measured spectra is critical for the reliable assay. The present method for blood glucose assay has been applied to one Type 1 diabetic. The correlation coefficient between the blood glucose content predicted by NIR spectra and those measured by finger-prick was 0.928 and the standard error of prediction was 32.2 mg/dL. These results demonstrate the potential of our methodology for noninvasive NIR blood glucose assay.

3-D eddy current analysis in permanent magnet of interior permanent magnet motors

Interior permanent magnet motors are widely used in various fields. However, in high-speed operations, it is important to decrease the eddy current loss in the permanent magnet. Therefore, we propose to divide the permanent magnet. This paper describes a practical technique to analyze the eddy current in the divided magnet. The effect of division of permanent magnet on eddy current loss is also quantitatively clarified.

Numerical analysis of electromagnetic forces in low voltage AC circuit breakers using 3-D finite element method taking into account eddy currents

It is necessary for the optimum design of low voltage circuit breakers to analyze electromagnetic forces acting on the contact systems when the circuit breakers interrupt fault currents. In this paper, the forces which are known as the magnetic blowout force acting on the arc and the electromagnetic repulsion force acting on the moving contact arm are obtained by using the 3-D finite element analysis taking into account eddy currents. It is shown that our 3-D analysis is capable of evaluating a new design of contact systems in low voltage ac switching devices.

Dynamic Analysis of Linear Resonant Actuator Driven by DC Motor Taking into Account Contact Resistance Between Brush and Commutator

This paper describes a highly accurate computation technique to obtain the dynamic characteristics of a linear resonant actuator (LRA) driven by the dc brush motor and a magnetic conversion mechanism employing the 3-D finite-element method. In this calculation, the contact resistance between brush and commutator of the dc brush motor is taken into consideration in the electric circuit equation coupled with magnetic field equation. The influences of the contact resistance on the dynamic characteristics are quantitatively investigated, and the importance of the use of appropriate contact resistance is clarified through the comparison with the measurement.

Trajectory Analysis of 2-D Magnetic Resonant Actuator

A novel 2-D magnetic resonant actuator is presented, and the influences of frequency and phase of the input voltage waveform on the trajectory of the armature are computed using the three-dimensional finite element method.

Dynamic Analysis of Electromagnetic Impact Drive Mechanism Using Eddy Current

This paper presents a dynamic analysis method of an electromagnetic impact (EMI) drive mechanism by 3-D finite element method (FEM). The transient and EMI torque are computed when the interlinkage flux of conductor is rapidly changed. The usefulness of this method is confirmed by comparing the calculated results with the measured ones

Eddy current damping analysis of laser marker using 3-D finite element method

This paper presents the numerical method for the damping analysis of a pendulum in a laser marker with the eddy current-brake. In this method, the eddy current analysis is coupled with two-dimensional (2-D) motion analysis employing the three-dimensional finite element method. The usefulness of this method is confirmed through the comparison with the computed and measured results of the 2-D damping trajectory of the pendulum

Dynamic Analysis Method of Linear Resonant Actuator With Multimovers Employing 3-D Finite Element Method

This paper proposes the dynamic analysis method of a linear resonance actuator with multimovers under PWM (Pulse Width Modulation) feedback control employing the 3-D finite element method (FEM). The effectiveness of this method is shown by the comparison with the experimental results. Furthermore, the effect of a link-spring on each mover motion is clarified.

Multimotion analysis of opening and closing sensor for windows using 3-D finite-element method

The three-dimensional finite-element method coupled with the rotation and linear motion of plural actuators has been developed. This method is applied to obtain the dynamic characteristics of an opening and closing sensor for windows with two armatures. The usefulness of this method is verified through the comparison of the measured results. Furthermore, an improved sensor is proposed and its effectiveness is clarified

Dynamic response analysis of opening and closing sensor for windows

This paper presents a new three-dimensional finite element approach coupled with the rotation and linear motion equations simultaneously. This method is applied to obtain the dynamic characteristics of an opening and closing sensor for windows. The usefulness of this method is verified through the comparison with the measured results.