Background Several large epidemiologic studies and clinical trials have included echocardiography, but images were stored in analog format and these studies predated tissue Doppler imaging (TDI) and speckle-tracking echocardiography (STE). We hypothesized that digitization of analog echocardiograms, with subsequent quantification of cardiac mechanics using STE, is feasible, reproducible, accurate, and produces clinically valid results. Methods In the NHLBI HyperGEN study (N=2234), archived analog echocardiograms were digitized and subsequently analyzed using STE to obtain tissue velocities/strain. Echocardiograms were assigned quality scores and inter/intraobserver agreement was calculated. Accuracy was evaluated in (1) a separate second study (N=50) comparing prospective digital strain vs. post-hoc analog-to-digital strain; and (2) in a third study (N=95) comparing prospectively-obtained TDI e′ velocities with post-hoc STE e′ velocities. Finally, we replicated previously known associations between tissue velocities/strain, conventional echocardiographic measurements, and clinical data. Results Of the 2234 HyperGEN echocardiograms, 2150 (96.2%) underwent successful digitization and STE analysis. Inter/intraobserver agreement was high for all STE parameters, especially longitudinal strain (LS). In accuracy studies, LS performed best when comparing post-hoc STE to prospective digital STE for strain analysis. STE-derived e′ velocities correlated with, but systematically underestimated, TDI e′ velocity. Several known associations between clinical variables and cardiac mechanics were replicated in HyperGEN. We also found a novel independent inverse association between fasting glucose and LS (adjusted β =−2.4 [95% CI −3.6,−1.2]% per 1-SD increase in fasting glucose; P<0.001). Conclusions Archeological echocardiography, the digitization and speckle-tracking analysis of archival echocardiograms, is feasible and generates parameters of cardiac mechanics similar to contemporary studies.

A new approach is developed to measure the dynamic characteristics of metal sheet under laser shock, including deformation velocity, strain, and strain rate. The detecting laser beam is partially shaded by the target deformation induced by the laser action. A photodiode transforms the received beam intensity real time into an electrical signal which could record the process of the target deformation. The functional relation between the electrical signal and the deformation of the metal sheet is derived. The deformation curve of a thin aluminum and the velocity curve of its deformation are also obtained during the experiment. The results indicate that the average velocity of the elastic deformation of the target can reach 2.999×10 3 m/s in the central area. This new method provides an approach in the study of the effect of strain rate on deformation.OCIS codes: 320. 7100, 350.4600, 140.3580, 120.1880, 120.7250. doi: 10.3788/COL201210.043201. Laser shock forming (LSF) of metal sheets is a new and competitive laser-based manufacturing technology [1] . When a high-power, short-pulse laser acts on a metal surface, plasma with high temperature and pressure is produced in a very short time because of laser energy absorption. Under the restraint layer, the plasma expands and explodes, resulting in a strong shock wave that propagates in the metal. The foregoing is a dynamic response process with high strain rate, so it changes the microstructure and mechanical properties of the metal [2−4]

A glasses defect inspection system is researched and developed according to the principle of light scattering and visual inspection method, which is based on the machine vision. In order to achieve the classification of glasses, the functions of image acquisition, simple image processing, grading and sorting of glasses are designed in this system. Operation of parallel structure is adopted in this system. Forwardlighting by low-angled-ring-LED is used to get the clear images of the defects in or on the surface of the glasses, such as speckles, impurities, feathers and so on. Image processing and glasses grading based on normalization algorithms are used to acquire the identifying information of various defects of glasses. Experiment results show that the detection system, which can detect all the kinds of defects of the glasses, has high processing speed and strong anti-interference capacity. The size of the smallest defect that can be detected by the system is 0.03mm, and the average detection time of each glass is less than 2s.

No abstract

A novel optoelectronic measurement system using a beamshading technique is developed to detect the dynamic characteristics of a metal sheet under laser shock in laser shock forming (LSF), including deformation, strain, and strain rate. Experiments conducted yield the dynamic deformations at two points on an aluminum sheet with a thickness of 0.25 mm in LSF. The average strain rates calculated in the experiments are 5.46 × 10 2 , 4.71 × 10 2 , and 3.59 × 10 2 s −1 when the targets were hit by laser pulses with energies of 5, 6, and 8 J, respectively. The results show that the strain rate induced by laser shocking is not at the ultrahigh level of 10 6 -10 7 s −1 as generally estimated in past studies, which offers an experimental reference for the deformation study of strainrate-dependent metal materials in LSF.