1,721,034 research outputs found
A novel method for the simultaneous measurement of temperature and strain using a three wire connection
No full textA novel methodology to simultaneously measure strain and temperature by means of an electrical resistance strain gauge powered by an ac signal and connected to a strain indicator by means of thermocouple wires is proposed. The experimental validation of the viability of this method is conducted by means of a purely electrical simulation of both strain and temperature signals, respectively from -2000 to 2000 mum m(-1) and -250 to 230 degreesC. The results obtained showed that strain measurement is affected by an error always less than +/-2 mum m(-1) for the whole range of simulated strains, while the error in temperature evaluation is always less than 0.6 degreesC. The effect of cross-talk between the two signals was determined to be insignificant
Experimental analysis of the airway circuit effects on breathing pattern generated by neonatal pulmonary ventilators
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The “Strain Gage-ThermoCouple”: a novel device for simultaneous strain and temperature measurement
No full textA novel methodology for simultaneous strain and temperature measurements by means of an ac powered electrical resistance strain gauge connected to a strain conditioner using thermocouple wires is proposed and validated. To this aim a specific device has been designed and implemented; the characteristics of the electronic circuit for signal conditioning have then been tested in order to determine the overall performances in temperature and strain measurements. The field verification of the method is conducted by imposing strain fields in the range from 0 to about 700 μm/m and temperature variations in the range from -10 to 100 °C. The difference between the strain measured by the proposed device and the one evaluated by a conventional digital strain meter was always less than 4 μm/m while the mean temperature discrepancy was 0.5 °C with respect to the reference temperature measured with a K-type thermocouple. Finally, compensation of temperature effects on the actual strain value has been performed while the temperature ranges from ambient to 100 °C with a residual error value of 1.4±1 μm/m
The “Leakage Current Sentinel”: a novel plug-in socket device for on-line biomedical equipment electrical safety surveillance
No full textThe Leakage Current Sentinel (LCS) has been designed and implemented for the detection of hazardous situations caused by dangerous earth leakage current values in intensive care units and operating theaters. The device, designed and manufactured with full compliance of the high risk environment requirements, is able to monitor online the earth leakage current and detect ground wire faults. Operation utilizes a microammeter with an overall sensitivity of 2.5x10(4) V/A. In order to assure the reliability of the device in providing alarm signals, the simultaneous presence of absorbed power current is monitored by means of another ammeter with decreased sensitivity (3.0 V/A). The measured root mean square current values are compared with reference values in order to send signals to NAND and OR complementary metal-oxide-semiconductor gates to enable audible and visible alarms according to the possible hazardous cases examined in the article. The final LCS packaging was shaped as a wall socket adapter for common electromedical device power cord plugs, with particular attention to minimizing its dimensions and to provide analog voltage outputs for both measured leakage and power currents, in order to allow automatic data acquisition and computerized hazardous situation management. Finally, a personal computer based automatic measuring system has been configured to simultaneously monitor several LCSs installed in the same intensive care unit room and, as a consequence, to distinguish different hazardous scenarios and provide an adequate alert to the clinical personnel whose final decision is still required. The test results confirm the effectiveness and reliability of the LCS in giving an alert in case of leakage current anomalous values, either in case of a ground fault or in case of a dangerous leakage current
Applicazione di reti di misura per il rilievo dei parametri ambientali nelle sale operatorie e nei locali di terapia intensiva - SOAR (Smart OperAting Room)
No full textEvaluation of error causes in the measurement of respiratory parameters during controlled ventilation: phase shift correction
No full textA reliability analysis of non parametric tests for linear drift evaluation
No full textDuring usual data gathering, the statistical analysis efficiency strongly depends on the noise level superimposed on the signal. It has been found that some well known statistical tests, commonly utilised in data acquisition in order to detect the presence of drift, can fail under some conditions. Thus, a statistical procedure for the predictive reliability estimation of the utilised statistical method could be useful in the design of experimental analysis. This paper reports the results of a simulation study carried out to evaluate the performance in drift detection of non-parametric tests suck as the Wald-Wolfowitz run test, in comparison with the Mann-Whitney, reverse arrangement test. In order to detect the sensitivity of the tests to evaluate a monotonous drift, a simulation program was developed. In the program a Gaussian raw data sequence with a linear pattern of variable slope and with variable variance was simulated and given as the input to the tests. The capability to detect the presence of drift as a function of angular coefficient and variance of the noise superimposed on the signal was verified. The obtained data were synthesised in graphs so that the experimentalist could determine preliminarily the effectiveness of each of the considered statistical methods in terms of percentage of success in detecting the presence of drift phenomena as a function of drift relevance and the noise amplitude. Finally, the graphs permitted the elucidation of the causes of contradictovy failing results observed in long term experimental analysis
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