The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few ...

Technical advances in the past 30 years in digital signal processing, analog to digital converters, computers, and software have resulted in significant gains in the field of experimental modal analysis. Advances in transducer technology (force and acceleration transducers) have also contributed to these gains. The present work first describes the development of the early electromechanical tran...

Eleven piezoelectric pressure transducers, each supporting an area of articular cartilage about 3 mm in diameter, were inserted through the bone of the acetabulum. Nine cadaveric hip joints, thus instrumented, were subjected to forces representing six instants in a typical level walking cycle, including the highest and lowest force. Under the highest force, the maximum pressure measured ranged ...

This study involved the development and testing of a system for the simultaneous in vitro measurement of tibiofemoral kinematics and patellofemoral kinematics and forces. Knee motion was tracked using a Vicon 370, and patellofemoral force was measured using a six degree-of-freedom transducer based on the design of Singerman et al. Using this system, twelve knee specimens were tested in supine l...

A bite force transducer consisting of two differential strain beams with four strain gages in a full bridge configuration was modified for measuring occlusal forces in rhesus monkeys. A procedure of muscle stimulation (20-50 V, 60 Hz, and 0.8 ms duration) produced maximal unilateral masticatory muscle contraction when stimulating electrodes were placed in the masseter muscle. Tests of this proc...

The bouncing bow, as used in rapid spiccato and ricochet bowing, has been studied. Dynamical tests were made by monitoring the force history when the bow was played by a mechanical device against a force transducer as a substitute to the string. The action of the bow stick was investigated by modal analysis. Bows made of wood, fibre glass, and carbon fibre composites were studied and compared, ...

We designed and developed a confocal acoustic radiation force optical coherence elastography system. A ring ultrasound transducer was used to achieve reflection mode excitation and generate an oscillating acoustic radiation force in order to generate displacements within the tissue, which were detected using the phase-resolved optical coherence elastography method. Both phantom and human tissue...

Background: Vibro-acoustography is an elasticity imaging method that images the acoustic response of a material to a localized harmonic excitation generated by ultrasound radiation force [Fatemi and Greenleaf, Science 280:82-85, 1998]. Proper beam forming for the stress field (radiation force) of the probing ultrasound is very important because it determines the resolution of the imaging system...

This study examined the influence of frequency and direction of force application on psychophysically acceptable forces for simulated work tasks. Fifteen male participants exerted psychophysically acceptable forces on a force transducer at 1, 3, or 5 repetitions per minute by performing both a downward press and a pull toward the body. These exertions were shown previously to be strength and ba...

Strength is a fundamental quality necessary in achieving optimal physical function and is defined as the ability to produce more force.(Siff M; Stone MH et al., 1993). Thus the display of strength has characteristics which include a magnitude, rate and direction. The force production can be measured by isotonic, isometric or isokinetic methods. The isotonic techniques require lifting a particul...