scholarly journals Large-Scale Non-Linear 3D Reconstruction Algorithms for Electrical Impedance Tomography of the Human Head

2007 ◽  
pp. 3862-3865 ◽  
Author(s):  
Lior Horesh ◽  
M. Schweiger ◽  
S. R. Arridge ◽  
D. S. Holder
Keyword(s):  
3D Reconstruction ◽  
Electrical Impedance Tomography ◽  
Large Scale ◽  
Electrical Impedance ◽  
Human Head ◽  
Reconstruction Algorithms ◽  
Impedance Tomography ◽  
Non Linear

scholarly journals Self-Abrading Servo Electrode Helmet for Electrical Impedance Tomography

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7058
Author(s):  
James Avery ◽  
Brett Packham ◽  
Hwan Koo ◽  
Ben Hanson ◽  
David Holder
Keyword(s):  
Acute Stroke ◽  
Electrical Impedance Tomography ◽  
Large Scale ◽  
Electrical Impedance ◽  
Applied Pressure ◽  
High Sensitivity ◽  
Haemorrhagic Stroke ◽  
Contact Impedance ◽  
Impedance Tomography ◽  
Skin Contact

Electrical Impedance Tomography (EIT) is a medical imaging technique which has the potential to reduce time to treatment in acute stroke by rapidly differentiating between ischaemic and haemorrhagic stroke. The potential of these methods has been demonstrated in simulation and phantoms, it has not yet successfully translated to clinical studies, due to high sensitivity to errors in scalp electrode mislocation and poor electrode-skin contact. To overcome these limitations, a novel electrode helmet was designed, bearing 32 independently controlled self-abrading electrodes. The contact impedance was reduced through rotation on an abrasive electrode on the scalp using a combined impedance, rotation and position feedback loop. Potentiometers within each unit measure the electrode tip displacement within 0.1 mm from the rigid helmet body. Characterisation experiments on a large-scale test rig demonstrated that approximately 20 kPa applied pressure and 5 rotations was necessary to achieve the target 5 kΩ contact impedance at 20 Hz. This performance was then replicated in a simplified self-contained unit where spring loaded electrodes are rotated by servo motors. Finally, a 32-channel helmet and controller which sequentially minimised contact impedance and simultaneously located each electrode was built which reduced the electrode application and localisation time to less than five minutes. The results demonstrated the potential of this approach to rapidly apply electrodes in an acute setting, removing a significant barrier for imaging acute stroke with EIT.

Recycling Krylov subspaces for efficient large-scale electrical impedance tomography

2010 ◽  
Vol 199 (49-52) ◽  
pp. 3101-3110 ◽  
Author(s):  
Luís Augusto Motta Mello ◽  
Eric de Sturler ◽  
Glaucio H. Paulino ◽  
Emílio Carlos Nelli Silva
Keyword(s):  
Electrical Impedance Tomography ◽  
Large Scale ◽  
Electrical Impedance ◽  
Krylov Subspaces ◽  
Impedance Tomography

scholarly journals Research electrical impedance tomography system suitable for making in out of factory conditions.

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
A.V. Korjenevsky ◽  
Keyword(s):  
Image Reconstruction ◽  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Direct Interaction ◽  
Measuring System ◽  
Dynamic Visualization ◽  
Reconstruction Algorithms ◽  
Impedance Tomography ◽  
Tomography System ◽  
Wireless Interfaces

The objective of this work is to present the first results of the development of an electrical impedance tomography system assembled from ready-made blocks with free software. Electrical impedance tomography is considered as a possible alternative and adjunct to computer tomography in lung diagnostics. One of the problems along this path is the mutual inaccessibility of equipment of an acceptable level for research physicians and of contacts with such physicians for the developers. An easily reproducible EIT hardware platform from ready-made modules and open source software have been developed and tested as an option for enthusiastic researchers who do not have sufficient experience to independently develop the hardware and software and the means to purchase expensive commercial devices. An evaluation board for an integrated bioimpedance meter, produced by the microcircuit manufacturer, is used to implement the main elements of the measuring system. The 16-channel multiplexers are also available as ready-made modules. A high-performance controller module based on a 32-bit system-on-chip ESP32 with built-in wireless interfaces has a compiler and SDK ported to the Arduino environment. This makes customization and testing of the embedded software possible for non-core professionals. Image reconstruction algorithms are available online on the Institute's server. Both dynamic (visualization of changes only) and static imaging are possible. The results of tomography system testing on the phantom and on the human body demonstrated the high quality of the data collected. Improving the speed of the measuring system and adding software functions, including the use of wireless interfaces for data transmission and direct interaction with the image reconstruction server are topical tasks.

A comparison of headnet electrode arrays for electrical impedance tomography of the human head

2003 ◽  
Vol 24 (2) ◽  
pp. 527-544 ◽  
Author(s):  
A T Tidswell ◽  
A P Bagshaw ◽  
D S Holder ◽  
R J Yerworth ◽  
L Eadie ◽  
...  
Keyword(s):  
Electrical Impedance Tomography ◽  
Electrical Impedance ◽  
Human Head ◽  
Electrode Arrays ◽  
Impedance Tomography
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