A Low-Cost Instrumentation System for Seismic Hazard Assessment in Urban Areas.

The development and application of a low-cost instrumentation system for seismic hazard assessment in urban areas are described in the present study. The system comprises a number of autonomous triaxial accelerographs, designed and manufactured in house and together with dedicated software for device configuration, data collection and further postprocessing. The main objective is to produce a detailed view of strong motion variability in urban areas, for at least light intensity strong motion events. The overall cost of the developed devices is at least ten times lower than the respective commercial units, hence their deployment as an ultra-dense network over the area of interest can be significantly cost-effective. This approach is considered an efficient complement to traditional microzonation procedures, which are typically based on relatively few actual recordings and the application of theoretical methodologies to assess the strong motion distribution. The manufactured devices adopt micro-electro-mechanical (MEMS) digital sensor technology for recording acceleration, whereas the accompanying software suite provides various configuration options, quick browsing, analyzing and exporting of the recorded events, as well as GIS type functionality for seamlessly producing explicit seismic hazard maps of the considered area. The evaluation of system performance was based on shaking table and real field comparisons against high accuracy commercial accelerographs. The study concludes with a real application of the proposed system in the form of an ultra-dense network installed at the city of Lefkada, an earthquake prone urban area in Greece, and the following compilation of explicit shakemaps.

The Comparison of the TOF Ratios between Electromyograph and Accelerograph following Vecuronium Administration / 대한마취과학회지

The present study was firstly undertaken in an attempt to compare simultaneously EMG(electromyography) and two new ACC(accelerography) reponses in the both hand following vecuronium administration in 26 ASA 1 or 2 adult patients undergoing general anesthesia. In the three NMT monitors, stimulating electrodes are applied similarly over the ulnar nerve on the volar side of the wrist, but the evoked EMG(Relaxograph, Datex Co.) responses obtained from the hypothenar muscles, TOFGUARD(Biometer Co.) responses from adductor pollicis and ParaGraph(Utah Med. Prod. Co.) responses from both muscles of hypothenar and thenar muscle of the hand respectively. Following induction of anesthesia with thiopental sodium(5 mg/kg) and vecuronium(0.08 mg/kg) intravenously, endotracheal intubation was facilitated and anesthesia was maintained with a mixture of enflurane(1~2%) and N2O(50%) . After loss of consciousness, the assessment of the neuromuscular blockade was started. We compared simultaneously TR(train-of-four ratio) responses of EMG at the one hand, and two new ACC named TOF-GUARD and ParaGraph at the other hand respectively during evoked recovery from vecuronium induced neuromuscular blockade. The result was the greater depression of TR response in TOF-GUARD and the lesser depression of TR response in ParaGraph than those in EMG. But test for parallelism did not show a statistically significant difference between the slope of these regression lines. Conclusively, the regression line for TR seems to be tend to give an impression that two new ACC named TOF-GUARD and ParaGraph would be suitable in the assessment of neuromuscular blockade in clinical anesthesia.

The comparison among Mechanical, Electromyographic and Accelerographic responses during recovery from vecuronium induced neuromuscular blockade / 대한마취과학회지

As the use of muscle relaxants routinize in the clinical general anesthesia, the proper estimation of neuromuscular blockade and recovery is needed for the more safe anesthetic management. Three recording methods of measurement in recovery are available; measurement of the evoked mechanical responses (mechanography), measurement of the evoked electrical responses (electromyography), and measurement of the acceleration of the muscle responses, The purpose of this study was to evaluate the correlations among mechanomyographic, electromyographic and accelerographic responses during recovery from vecuronium induced neuromuscular blockade. 15 ASA class 1 adult patients were studied. Measurements were as follows: 1) Recovery time of T(1)/Tc, of 25%, 50%, 75%, 90% and 100% in each device. 2) Recovery index in each device 3) The values of T(1)>Tc, in EMG and ACC corresponding ta that of MMG. 4) The values of TOF ratio in EMG and ACC corresponding to that of MMG. The results were as follows: 1) Recovery time of T(1).