Electrical impedance tomography (EIT) is a technique for reconstructing the conductivity distribution by injecting currents at boundary of subject and measuring resulting changes in voltage. Image reconstruction EIT nonlinear ill-posed inverse problem. The Tikhonov method with L2 regularization always used to solve However, smoothes sharp or discontinue areas reconstruction. using L1 allows addressing this difficulty. In paper, sum absolute values substituted squares form regularization,...

Electrical impedance tomography (EIT) is a technique that calculates the distribution of electrical living body by measuring surface voltage body, which available for continuous monitoring lung function to reduce risk intensive injury. The global inhomogeneity index (GI) employed assess degree ventilation homogeneity at different levels GI values calculated in current research are all based on two-dimensional EIT reconstruction images; however, this method does not correctly detect low In...

Electrical impedance tomography (EIT) aims to estimate the electrical properties at interior of an object from current-voltage measurements on its boundary. It has been widely investigated due advantages low cost, non-radiation, non-invasiveness, and high speed. Image reconstruction EIT is a nonlinear ill-posed inverse problem. Therefore, regularization techniques like Tikhonov are used solve A sparse based L1 norm exhibits superiority in preserving boundary information sharp changes or...

Amplitude demodulation is essential in image reconstruction for electrical capacitance tomography (ECT). In this paper, an amplitude method proposed based on singular value decomposition (SVD), which can substitute the role of phase-sensitive ECT. First, M × N Hankel matrix constructed a set discrete samples. Then, SVD operation performed matrix. Finally, mathematical expression between sinusoid and effective values given; i.e., first two are used to estimate information acquired signal. The...

Abstract Due to the viscous shear stress, there is an obvious error between real flow rate and rotameter indication for measuring fluid medium. At 50 cSt maximum of DN40 orifice up 35 %. The viscosity effects on are investigated using experimental theoretical models. Wall jet concentric annulus laminar theories were adapted study influence viscosity. And a new formula obtained calculating fluid. data analyzed compared with calculated results. high results 6.3 %, indicating that proposed...

A low-energy low-dose γ-ray computed tomography (CT) system used in the gas-liquid two-phase pipe flow measurement has been studied at Tianjin University recent years. The CT system, having a third-generation X-ray scanning configuration, is comprised of one 300mCi 241Am source and 17 CdZnTe detector units achieves spatial image resolution about 7 mm. It primarily intended to measure provide improvement suggestions for industrial system. Recently we improve design reconstruction from...

Electrical impedance tomography (EIT) reconstruction is a nonlinear and ill-posed problem. Exact of an EIT image inverts high dimensional mathematical model to calculate the conductivity field, which causes significant problems regarding that computational complexity will reduce achievable frame rate, considered as major advantage imaging. The single-step method, state estimation projection method were always used accelerate process. basic principle these methods complexity. However,...

In the application of oil-air lubrication system, electrical capacitance tomography (ECT) provides a promising way for monitoring oil film in pipelines by reconstructing cross sectional distributions real time. While case small diameter pipe and thin film, thickness is hard to be observed visually since interface air not obvious reconstructed images. And existence artifacts reconstructions has seriously influenced effectiveness image segmentation techniques such as level set method. Besides,...

Purpose Electrical impedance tomography (EIT) is a technique for reconstructing the conductivity distribution by injecting currents at boundary of subject and measuring resulting changes in voltage. Image reconstruction EIT nonlinear problem. A generalized inverse operator usually ill-posed ill-conditioned. Therefore, solutions are not unique highly sensitive to measurement noise. Design/methodology/approach This paper develops novel image algorithm based on patch-based sparse...

Lung carcinoma has become one of the malignancies whose morbidity and mortality are growing significantly. Blood is a functional body fluid, it delivers oxygen nutrients to other parts body, pathway tumor metastasis. Thi

Component fraction (CF) is one of the most important parameters in multiple-phase flow. Due to complexity solid-liquid two-phase flow, CF estimation remains unsolved both scientific research and industrial application for a long time. Electrical resistance tomography (ERT) an advanced type conductivity detection technique due its low-cost, fast-response, non-invasive, non-radiation characteristics. However, when existing ERT method used measure value flow dredging engineering, there are at...

Electrical impedance tomography (EIT) aims to estimate the electrical properties at interior of an object from current-voltage measurements on its boundary. Regularization is effective method for solution such ill-posed inverse problems. The aim this work explore more regularization-based solutions through application preconditioned LSQR (PLSQR) study 3D EIT reconstruction. Four different subspace splitting methods, i.e., SVD, wavelet transform, cosine transform schemes and Krylov subspace,...

Electrical impedance tomography (EIT) aims to estimate the electrical properties at interior of an object from current-voltage measurements on its boundary. The image reconstruction for EIT is inverse problem, which both nonlinear and ill-posed. Little noise in measured data can cause large errors estimated conductivity. Image using l <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> regularization allows addressing this difficulty,...

Image reconstruction for Electrical Resistance Tomography (ERT) is an ill-posed nonlinear inverse problem. Considering the influence of sparse measurement data on quality reconstructed image, l1-regularized least-squares program (l1 regularized LSP) introduced to solve problem in this paper. To meet need high speed ERT, fast iterative shrinkage-thresholding algorithm (FISTA) employed image our work. Simulation results FISTA and l1_ls show that l <sub...

In order to overcome the disadvantages that simple genetic algorithm had in low-dimensional and multimodal function optimization, an improved was proposed. The new divided search interval into different areas by method of orthogonal decomposition, produced initial populations individual distribution density using algorithm, gave each attribute marked area which it guaranteed there more than one during operating process algorithm. Particle swarm introduced mutation operation shortage was,...

As an important means in electrical impedance tomography (EIT), multi-frequency phase-sensitive demodulation (PSD) can be viewed as a matched filter for measurement signals and optimal linear the case of Gaussian-type noise. However, additive noise usually possesses impulsive characteristics, so it is challenging task to reduce PSD effectively. In this paper, approach reduction EIT presented. Instead filters, singular value decomposition employed pre-stage filtering module prior PSD, which...

Image reconstruction for electrical impedance tomography (EIT) is a nonlinear problem. A generalized inverse operator usually ill-posed and ill-conditioned. Therefore, the solutions EIT are not unique highly sensitive to measurement noise. To improve image quality, new algorithm based on patch-based sparse representation proposed. For each iterative step, sparsifying dictionary optimization performed alternately. The proposed has been evaluated by simulation with noise different conductivity...

Electrical resistance tomography (ERT) is considered a novel sensing technique for monitoring conductivity distribution. Image reconstruction of ERT an ill-posed inverse problem. In this paper, improved regularization method presented to solve issue. We adopted homotopic mapping choose the parameter iterative Tikhonov algorithm. The standard normal distribution function was used continuously adjust parameter. Subsequently, resultant image vector deployed as initial value algorithm improve...