OBJECTIVE To develop a modification of the pendulum test to allow evaluation of elbow spasticity. DESIGN The main difficulties of directly applying the conventional pendulum test to the elbow were the small inertia of the forearm and the uncomfortable posture. We designed an experimental apparatus similar to a clock pendulum and developed an elbow biomechanic model to measure objectively spas...

A novel control method of a three-phase PWM inverter with LC filter is proposed. The transfer function of LC filter is the same as that of 2nd order low pass filter(2nd LPF) which has a zero damping ratio. A simple method of implementing 2nd LPF with damping ratio is to add resistor to inductor or capacitor of LC filter. In an industrial application, it is not practical to adopt damping resisto...

Cell size, measured as either volume or mass, is a fundamental indicator of cell state. Far more tightly regulated than size is density, the ratio between mass and volume, which can be used to distinguish between cell populations even when volume and mass appear to remain constant. Here we expand upon a previous method for measuring cell density involving a suspended microchannel resonator (SMR...

Control systems for shakers are necessary to remove both shaker dynamics as well as coupling effects between the shaker and the structure under test. Little attention has been given to shaker control for nonlinear structures. This paper presents the design, implementation and results of a shaker controller for a horizontal, cantilevered beam subjected to a non-uniform magnetic field. The object...

Abstract: Electromechanical coupling defines the ratio of electrical and mechanical energy exchanged during a flexure cycle of a piezoelectric actuator. This paper presents an analysis of the dynamic electromechanical coupling factor (dynamic EMCF) for cantilever based piezoelectric actuators and provides for the first time explicit expressions for calculation of dynamic EMCF based on arrangeme...

Measured damping coefficients of six different perforated micromechanical test structures are compared with damping coefficients given by published compact models. The motion of the perforated plates is almost translational, the surface shape is rectangular, and the perforation is uniform validating the assumptions made for compact models. In the structures, the perforation ratio varies from 24...

The undamped naturalfrequency CO, and the damping ratio [ can be determined from a plot of the jiee motion of the system. If the damping is light, ( < 0.2, the lqqarithmic decrement can be used to determine the coeficients. Systems with moderate damping are those in the range 0.2 < ( -C 1.2. A methodfor determining vibration parameters for systems with moderate damping is presented here. The me...

Isotope Ratio Mass Spectrometry (IRMS) is a specialized technique used to provide information about the geographic, chemical, and biological origins of substances. The ability to determine the source of an organic substance stems from the relative isotopic abundances of the elements which comprise the material. Because the isotope ratios of elements such as carbon, hydrogen, oxygen, sulfur, and...