BACKGROUND Model-based reconstruction algorithms have shown potentials over conventional strain-based methods in quasi-static elastographic image by using realistic finite element (FE) or bio-mechanical model constraints. However, it is still difficult to properly handle the discrepancies between the model constraint and ultrasound data, and the measurement noise. METHODS In this paper, we ex...

In this paper, a low cost optical flow sensor is combined with an external laser device to measure surface displacements and mechanical oscillations. The measurement system is based on applying coherent light to a diffuser surface and using an optical flow sensor to analyze the reflected and transferred light to estimate the displacement of the surface or the laser spot. This work is focused on...

Traditionally structural response due to severe conditions has been measured using accelerometers. However it is a relative acceleration measurement. The displacement from acceleration measurement cannot be obtained directly by simply applying the laws of motion through double integration. GPS-RTK offers direct displacement measurements for dynamic monitoring, but it has its own limitations. Th...

The development of image sensors and optics lenses has contributed to the rapidly increasing use of vision-based methods as noncontact measurement methods in many areas. A high-speed camera system is developed to realize the displacement measurement in real time. Conventional visual measurement algorithms are commonly subjected to various shortcomings, such as complex processes, multiparameter ...

Introduction: Quantitative functional cardiac imaging can be used to characterize healthy and diseased myocardial tissues. Imaging protocols that measure 3D motion of the heart can lead to more accurate characterization than 2D approaches. However, 3D protocols are often too time-consuming for clinical feasibility. zHARP is a fast imaging technique that can quantify 3D myocardial motion from a ...

A MR method is presented for measuring pulse wave velocity (PWV) and its application to assessing stiffness in the human thoracic aorta. This one-dimensional (1D) flow displacement method applies a single RF comb excitation to the vessel, followed by an oscillating frequency encoding gradient, each oscillation providing a 1D projection of the vessel, enabling one to track fluid motion. The curr...

OBJECTIVES To determine the accuracy of orchidometry and ultrasonography for measuring the testicular volume by comparing the resultant measurements with the actual testicular volume in humans. METHODS The testicular volume of 40 testes from 20 patients with prostate cancer (mean age +/- SD 74.5 +/- 7.5 years) was measured using the Prader orchidometer and ultrasonography before therapeutic b...

The use of tracking interferometers has gained industrial application for the testing and the calibration of measuring and production machines. The concept is based on sequential multilateration [1] and can realize calibration uncertainties in the sub-micron order. Another application for tracking interferometers is the real-time multilateration for accurate and highly dynamic measurement of 3D...

High-rise buildings subjected to lateral loads such as wind and earthquake loads must be checked not to exceed the limits on the maximum lateral displacement or the maximum inter-story drift ratios. In this paper, a sensing model for deformed shapes of a building structure in motion is presented. The deformed shape sensing model based on a 2D scanner consists of five modules: (1) module for acq...

An optical fiber sensing method based on a reflective grating panel is demonstrated for lateral displacement measurement. The reflective panel is a homemade grating with a periodic variation of its refractive index, which is used to modulate the reflected light intensity. The system structure and operation principle are illustrated in detail. The intensity calculation and simulation of the opti...