scholarly journals Separating ventricular activity in thoracic EIT using 4D image-based FEM simulations

2021 ◽  
Vol 7 (2) ◽  
pp. 871-874
Author(s):  
Birgit Stender ◽  
Oliver Blanck ◽  
Sebastian D. Reinartz ◽  
Olaf Dössel
Keyword(s):  
Stroke Volume ◽  
Measurement Data ◽  
Measurement Information ◽  
Voltage Measurement ◽  
Image Region ◽  
Impedance Tomography ◽  
External Monitoring ◽  
Central Hemodynamic ◽  
Ventricular Activity ◽  
Monitoring Information

Abstract One challenge in central hemodynamic monitoring based on electrical impedance tomography (EIT) is to robustly detect ventricular signal components and the corresponding EIT image region without external monitoring information. Current stimulation and voltage measurement of EIT were simulated with finite element porcine torso models in presence of a multitude of thoracic blood volume shifts. The simulated measurement data was examined for linear dependence on changes in stroke volume. Based on the results the EIT measurement information regarding stroke volume changes is sparse

Electrical impedance tomography in 3D flood embankments testing – elastic net approach

2019 ◽  
Vol 42 (4) ◽  
pp. 680-690
Author(s):  
Tomasz Rymarczyk ◽  
Edward Kozłowski ◽  
Grzegorz Kłosowski
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Visual Analysis ◽  
Measurement Techniques ◽  
Measurement Data ◽  
Reconstruction Algorithm ◽  
Elastic Net ◽  
Destructive Testing ◽  
Impedance Tomography ◽  
High Resolution Images

The article presents non-destructive testing based on electrical impedance tomography (EIT) for spatial (3D) monitoring of flood embankments. Therefore, to solve the inverse problem of the EIT, an effective algorithm based on multiple elastic nets has been developed. The originality of the solution is based on the application of many elastic net algorithms as functions, each of which, based on the vector of all measurements, generates the value of a single pixel for the reconstructed image. In this way, the set of elastic nets is equal to the resolution of the image output. Such an approach, although requiring more computing power, yields high resolution images. In addition, the presented algorithms are characterized by high noise immunity and distortion of measurement data. Five different electrode systems were tested in the samples and compared with each other in two measurement variants (stimulations). A reconstruction made on the basis of actual measurements obtained from the physical model was also presented. The presented solution provides a visual analysis of seepages and leaks, which allows for quick and effective intervention and possible prevention of dangers. The research proved that the use of tomographic measurement techniques in combination with the image reconstruction algorithm based on elastic net allows for non-invasive and very accurate spatial assessment of leaks and damages of flood embankments. The received results confirm the effectiveness of the presented research.

scholarly journals Compensation for Geometrical Deviations in Additive Manufacturing

Technologies ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 83 ◽  
Author(s):  
Christoph Hartmann ◽  
Philipp Lechner ◽  
Benjamin Himmel ◽  
Yannick Krieger ◽  
Tim C. Lueth ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Measurement Data ◽  
Measurement Information ◽  
Geometrical Approach ◽  
Validation And Verification ◽  
Industrial Practice ◽  
Part Geometry ◽  
Forming Technology ◽  
Discrete Measurement ◽  
Compensation Approach

The design of additive manufacturing processes, especially for batch production in industrial practice, is of high importance for the propagation of new additive manufacturing technology. Manual redesign procedures of the additive manufactured parts based on discrete measurement data or numerical meshes are error prone and hardly automatable. To achieve the required final accuracy of the parts, often, various iterations are necessary. To address these issues, a data-driven geometrical compensation approach is proposed that adapts concepts from forming technology. The measurement information of a first calibration cycle of manufactured parts is the basis of the approach. Through non-rigid transformations of the part geometry, a new shape for the subsequent additive manufacturing process was derived in a systematic way. Based on a purely geometrical approach, the systematic portion of part deviations can be compensated. The proposed concept is presented first and was applied to a sample fin-shaped part. The deviation data of three manufacturing cycles was utilised for validation and verification.

Geometric Algorithms for Kinematic Calibration of Robots Containing Closed Loops

2003 ◽  
Vol 125 (1) ◽  
pp. 23-32 ◽  
Author(s):  
C. C. Iuras¸cu ◽  
F. C. Park
Keyword(s):  
Measurement Data ◽  
Measurement Information ◽  
Kinematic Calibration ◽  
Geometric Framework ◽  
Closed Loops ◽  
Ambient Manifold ◽  
Error Measures ◽  
Calibration Problem ◽  
Redundantly Actuated ◽  
High Level

We present a coordinate-invariant, differential geometric formulation of the kinematic calibration problem for a general class of mechanisms. The mechanisms considered may have multiple closed loops, be redundantly actuated, and include an arbitrary number of passive joints that may or may not be equipped with joint encoders. Some form of measurement information on the position and orientation of the tool frame may also be available. Our approach rests on viewing the joint configuration space of the mechanism as an embedded submanifold of an ambient manifold, and formulating error measures in terms of the Riemannian metric specified in the ambient manifold. Based on this geometric framework, we pose the kinematic calibration problem as one of determining a parametrized multidimensional surface that is a best fit (in the sense of the chosen metric) to a given set of measured points in both the ambient and task space manifolds. Several optimization algorithms that address the various possibilities with respect to available measurement data and choice of error measures are given. Experimental and simulation results are given for the Eclipse, a six degree-of-freedom redundantly actuated parallel mechanism. The geometric framework and algorithms presented in this article have the desirable feature of being invariant with respect to the local coordinate representation of the forward and inverse kinematics and of the loop closure equations, and also provide a high-level framework in which to classify existing approaches to kinematic calibration.

An Interactive Endotracheal Suctioning Simulator Which Exhibits Vital Reactions: ESTE-SIM

2019 ◽  
Vol 13 (4) ◽  
pp. 490-498 ◽  
Author(s):  
Shunsuke Komizunai ◽  
Shinji Ninomiya ◽  
Atsushi Konno ◽  
Satoshi Kanai ◽  
Tadayoshi Asaka ◽  
...  
Keyword(s):  
Nursing Education ◽  
Health Care Professionals ◽  
Measurement Data ◽  
Suction Catheter ◽  
Measurement Information ◽  
Care Providers ◽  
Endotracheal Suctioning ◽  
Training Environment ◽  
Actual Measurement ◽  
Vital Reactions

This paper describes a next-generation nursing education simulator, the endotracheal suctioning training environment simulator (ESTE-SIM), which is capable of interactively reproducing vital reactions. With the spread of home treatment, care providers who have received a certain level of nursing education should be increased, not limited to conventional health-care professionals. A great gap exists between simulations under restricted conditions that have been practiced in conventional nursing education and those in the actual clinical site, thus creating a burden on nurses and patients. If a simulator that approaches real clinical situations can be developed, it will not only contribute to lessening the burden on nurses but also improve the quality of nursing care. The ESTE-SIM, which simulates endotracheal suctioning, can measure the movements of the suction catheter inserted in the trachea. The measurement information is used to estimate the progress of the nursing maneuver, which is then used to reproduce vital reactions, including dynamic facial expression changes based on projection mapping and monitor-displayed vital signs. To design and control the vital reactions, a mathematical model to determine the behavior of the simulator is formulated based on the actual measurement data of the vital reactions of patients and the experiential knowledge of nurses. By integrating these element technologies, we developed a novel interactive nursing education simulator capable of recreating typical vital reactions that occur during the basic endotracheal suctioning maneuver.

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