Estimating regional pulmonary blood flow in EIT with regularized deconvolution with a Tikhonov regularization

Electrical Impedance Tomography (EIT) is a clinically used tool for bed-side monitoring of ventilation. Previous work also showed a high potential for lung perfusion monitoring with indicator-enhanced EIT. However, many research questions have yet to be answered before it can be broadly applied in clinical everyday life. The goal of this work is to evaluate a new method to improve EIT perfusion measurements. Pulmonary hemodynamic transfer functions were estimated using regularized deconvolution with Tikhonov regularization to estimate spatial perfusion parameters. The final comparison between EIT images and PET scans showed a median correlation of 0.897 for the images which were reconstructed using the regularized deconvolution. In comparison the previously used maximum slope method led to a median correlation of 0.868.

Determination Of Heat Transfer Characteristics Employing Modified Maximum Slope Method For Porous Media Heat Exchanger Using Al2O3–Water Nanofluids

It has been well documented in many literature that porous media and nanofluid can augment heat transfer in many engineering system. However the combined usage of these two media has not been given much attention in literature. The objective of the present work is to experimentally investigate porous media heat exchanger using Al2O3/water nanofluids. The heat transfer characteristics is determined using transient testing method wherein, only one fluid stream flows steadily throughthe test core, then a transient perturbation in the inlet fluid temperature is induced and the outletfluid temperature variation is measured continuously. The measured data is evaluated using the maximum slope method to obtain the heat transfer characteristics. The results show an increase in Nusselt number values with the use of nanofluids in porous media heat exchanger compared to water

An Optimized Algorithm to Measure Arterial Blood Pressure

Blood pressure is one of the most important indexes for human beings health. This paper presents an optimized algorithm to measure arterial blood pressure based on oscillometric technique. The bilateral filter and Gaussian-fitting method are respectively expressed to apply in noise eliminating, oscillation pulse extracting and curve fitting. The systolic pressure and diastolic pressure are determined by combination of proportional coefficient method, maximum slope method and curvature method. Moreover, a judgment for arrhythmias is employed in heart rate calculation. Experimental results have proved the precision and accuracy of the algorithm.

GRAVITY APPROXIMATION AND INTERPRETATION OF A TWO‐DIMENSIONAL VERTICAL FAULT

The error in depth determination due to the thin plate approximation of a two‐dimensional vertical fault is investigated by the maximum slope method and the traditional [Formula: see text] method. We show here that although the gravity curves for thin and thick faults are not greatly different, faults with large throws have significant percentage errors in the depth to the central plane which warrant attention in precision interpretation. When the ratio of the throw of the fault to its mid‐depth varies from 1.5 to 1.9, the percentage error in depth increases from 10 to more than 16 percent. The maximum slope method for determination of depth gives larger percentage errors compared to [Formula: see text] measures. When the fault throw is large, a gradient method may be used to find the principal parameters of a two‐dimensional vertical fault. The method is theoretically free from any ambiguity and has other advantages which may facilitate precise interpretation. The thin plate approximation should be avoided in such cases.