Biomedical electrode arrangement Patent

Electromedical garment, applying vectorcardiologic type electrodes to human torsos for data recording during physical activit

Volterra-series approach to stochastic nonlinear dynamics: linear response of the Van der Pol oscillator driven by white noise

The Van der Pol equation is a paradigmatic model of relaxation oscillations. This remarkable nonlinear phenomenon of self-sustained oscillatory motion underlies important rhythmic processes in nature and electrical engineering. Relaxation oscillations in a real system are usually coupled to environmental noise, which further enriches their dynamics, but makes theoretical analysis of such systems and determination of the equation's parameter values a difficult task. In a companion paper we have proposed an analytic approach to a similar problem for another classical nonlinear model, the bistable Duffing oscillator. Here we extend our techniques to the case of the Van der Pol equation driven by white noise. We analyze the statistics of solutions and propose a method to estimate parameter values from the oscillator's time series. We use experimental data of active oscillations in a biological system to demonstrate how our method applies to real observations and how it can be generalized for more complex models.Comment: 12 pages, 6 figures, 1 tabl

Gas low pressure low flow rate metering system Patent

Flowmeters for sensing low fluid flow rate and pressure for application to respiration rate studie

The young massive stellar cluster associated to RCW121

We report NIR broad and narrow band photometric observations in the direction of the IRAS17149-3916 source that reveal the presence of a young cluster of massive stars embedded in an HII region coincident with RCW121. These observations, together with published radio data, MSX and Spitzer images were used to determine some of the physical parameters of the region. We found 96 cluster member candidates in an area of about 1.5 x 2.0 square arcmin, 30% of them showing excess emission in the NIR. IRS 1, the strongest source in the cluster with an estimated spectral type of O5V-O6V ZAMS based on the color-magnitude diagram, is probably the main ionizing source of the HII region detected at radio wavelengths. Using the integrated Brgamma and the 5 GHz flux densities, we derived a mean visual extinction AV=5.49 magnitudes. From the observed size of the Brgamma extended emission, we calculated the emission measure E and the electron density ne, characteristic of compact HII regions.Comment: 18 pages, 8 figures, accepted for publication on AJ (February/2006

High- and low-pressure pneumotachometers measure respiration rates accurately in adverse environments

Respiration-rate transducers in the form of pneumotachometers measure respiration rates of pilots operating high performance research aircraft. In each low pressure or high pressure oxygen system a sensor is placed in series with the pilots oxygen supply line to detect gas flow accompanying respiration