The rapid printing of 3D parts with desired electrical properties enables numerous applications. Fused deposition modeling (FDM) using conductive thermoplastic composites has been a valuable approach for such fabrication. produced by FDM possess various controllable structural features, but the effects features on remain to be determined. This study investigated these resistivity and anisotropy 3D-printed ABS/CB composites. process parameters FDM, including layer thickness, raster width, air...

In electrical impedance tomography (EIT), it is difficult to obtain the intracranial due highly resistive skull enclosing brain. Therefore, a high-precision data acquisition system required for brain EIT. this paper, we used digital synthesis method and demodulation technique with high noise immunity eliminate random errors. Moreover, focused on two problems encountered during EIT acquisition: 1) shunt effect excitation current distributed capacitance between electrodes ground 2) common-mode...

We present a Python-based, open source Electrical Impedance Tomography (EIT) library called pyEIT. It is multiplatform software released under the Apache License v2.0. pyEIT has clean architecture and well documented. implements state-of-the-art EIT imaging algorithms also capable of simple 2D/3D meshing. written in Python. accelerates analysis offline data can be incorporated into clinical applications. In this paper, we focus on illustrating fundamental design principles by using some...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A study on correlation between structure and resistivity variations was performed for live adult human skull. The resistivities of 388 skull samples, excised from 48 flaps patients undergoing surgery, were measured at body temperature (36.5 <formula formulatype="inline"><tex>$^{\circ}$</tex></formula>C) using the well-known four-electrode method in frequency range 1–4 MHz. According to different...

An accurate impedance model of a skull plays an important role in the simulation research on source localization EEG and brain EIT (electrical tomography), etc. On basis large number resistivity data obtained from our previous measurement live human skull, this study we established equivalent circuit models six types samples 30 Hz–3 MHz frequency range analyzed fitting performance models. The are standard tri-layer, quasi-tri-layer, compact, quasi-compact, dentate suture squamous suture....

Delayed detection of an internal hemorrhage may result in serious disabilities and possibly death for a patient. Currently, there are no portable medical imaging instruments that suitable long-term monitoring patients at risk hemorrhage. Electrical impedance tomography (EIT) has the potential to monitor continuously as novel functional image modality instantly detect occurrence However, low spatial resolution high sensitivity noise this technique have limited its application clinics. In...

The dielectric properties of human liver were determined by characterization tissue absorption and coupling electromagnetic energy in the field. In this study ex-vivo hepatocellular carcinoma (

Magnetic induction tomography (MIT) is a contactless and noninvasive technique to reconstruct the conductivity distribution in human cross-section. In this paper, we want study feasibility of imaging low-contrast perturbation small volume object brains. We construct three-layer brain physical phantom which mimics real brains by introducing an artificial skull layer. Using our MIT data acquisition system on differential algorithm, have obtained series reconstructed images objects. All objects...

Brain electrical impedance tomography (EIT) is a difficult task as brain tissues are enclosed by the skull of high resistance and cerebrospinal fluid (CSF) low resistance, which makes internal resistivity information more to extract. In order seek single source drive pattern that suitable for EIT, we built realistic experimental setting simulates head with scalp, skull, CSF brain, compared performance adjacent, cross, polar pseudo-polar patterns in terms boundary voltage dynamic range,...

Dielectric properties are vital biophysical features of biological tissues, and activity is an index to ascertain the active state tissues. This study investigated potential correlation between dielectric activities human hepatic tissue with prolonged ex vivo time through regression analyses. The 26 cases normal at 10 Hz 100 MHz were measured from 15 min after isolation 24 h 37 °C 90% humidity. Cell morphologies, including nucleus area (NA) alteration rate intercellular (ICAR), analyzed as...

Current medical imaging techniques are not effective for timely detection of internal hemorrhage when the bleeding is slow and in small quantities. In this study, electrical impedance tomography (EIT) was applied to monitor intraperitoneal an animal model. Five healthy pigs three months old were used. The process simulated with injection anticoagulated blood which controlled by electronic syringe pump. injected rate no more than 100 ml h(-1) total volumes ranged from 300 500 ml. Sixteen...

To establish a high precision data acquisition system for multi-frequency electrical impedance tomography (EIT), series of methods were introduced. Those include building driving signal with up to four frequency components diminish the effect dynamic change tissues resistivity, extracting information by digital demodulator that can improve SNR 8 times. The established work at wide range from 1.6kHz 380kHz. Its CMRR is 74dB 100kHz. output current source 2M&#937; frequency. And measurement on...

More than half of the stroke patients are cause by cerebral ischemia/ hypoxia, and it is no means an easy affairs to detect ischemic tissue when rescuable drug intervention using traditional imaging technique. The purpose this paper testify feasibility monitoring ischemia. By a newly developed high precision data acquisition system specially configured method, series experiments were performed on 8 Chinese local rabbits, who have been induced with cortical ischemia photochemical method. This...

Stroke has a high mortality and disability rate should be rapidly diagnosed to improve prognosis. Diagnosing stroke is not problem for hospitals with CT, MRI, other imaging devices but difficult community without these devices. Based on the mechanism that electrical impedance of two hemispheres normal human head basically symmetrical can alter this symmetry, fast method called tomography (SEIT) proposed. In technique, (EIT) data measured from undamaged craniocerebral hemisphere (CCH)...

In electrical impedance tomography (EIT), measurements of developed surface potentials due to applied currents are used for the reconstruction conductivity distribution. Practical implementation EIT systems is known be problematic high sensitivity noise such systems, leading a poor imaging quality. present study, performance an induced current (ICEIT) system, where eddy using magnetic induction, was studied by comparing voltage simulated data, and examining quality with respect...

Magnetic Induction Tomography (MIT) of biological tissue is a contactless and noninvasive method to image the complex conductivity distribution or its changes inside human body. In this paper, 2D (two-dimensional) simulations forward problem in MIT are performed by finite element an inverse solver based on regularized Newton-Raphson developed reconstruct images from simulated measuring data. Preliminary simple head model presented. Images can be reconstructed successfully with using The...

Electrical impedance tomography (EIT) estimated the electrical conductivity distribution within a body. Bipolar drive pattern appeared in most EIT studies that current was injected with single source and sink. In present study, we built computational phantom compared quality of dynamic image terms data quality, resolution anti-noise performance associated three different bipolar patterns: polar pattern, pseudo-polar adjacent pattern. The results demonstrated is optimal.

This note describes an improved equivalent circuit analysis model for open-ended coaxial probes measurement of the dielectric properties biological tissues below gigahertz level. Some parameters in conventional that influence results were found to be still relative test sample and terminal admittance probe was dependent on frequency. not case with model. According simulation frequency range from 30 MHz 1 GHz, a polynomial expression fit frequency-admittance curve finally modified. The...

In this study, a serial EIT data acquisition system was constructed. It is consisted by digital synthesis based programmable current source, shield guard and sink feedback electrode interface subsystem, gain amplifier voltmeter, an orthogonal sequential demodulation impedance method. The has bandwidth of 1-190 kHz with imaging speed 1 fps. can produce the driving SNR higher than 89 dB, measure voltage difference CMRR 75 dB in bandwidth. measured results on calibration model show that it high...

Background Electrical impedance tomography is a continuous imaging method capable of measuring lung volume changes. The purpose this study was to examine whether EIT evaluating the degree obstructive ventilatory defect (OVD) on global and regional level. Methods 41 healthy subjects with no diseases 67 suffering from were examined using spirometry during forced vital capacity (FVC) maneuver. divided into control group (n = 41), early airway obstruction 26), mild 17), moderate 16) severe 8)...

Electrical impedance scanning (EIS) is a kind of potential bio-impedance measurement technology, especially aiding the diagnosis breast cancer in women. By changing frequency driving signal turn while keeping other conditions stable, multi-frequency results on object can be obtained. According to least square method and circuit theory, parameters two models are deduced when measured with data at multiple frequencies. The arcs, real imaginary parts trans-admittance coordinate, made by...