Dielectric properties of human brain tissue measured less than 10 h postmortem at frequencies from 800 to 2450 MHz

Schmid, Gernot; Neubauer, Georg; Mazal, Peter R.

doi:10.1002/bem.10123

Cited by 71 publications

(64 citation statements)

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“…A number of studies of the dielectric properties of different human tissue have been made, [20]- [23] and there is a clear indication of a significant contrast between blood and white and gray brain matter. Originating in our own work with microwave tomography applied to breast cancer detection, [24], we have developed a helmet with microwave patch antennas, signal processing methods based on a machine learning algorithm and have performed numerical and phantom studies of hemorrhagic stroke detection, [25], [26], with encouraging results.…”

Section: Introductionmentioning

confidence: 99%

Microwave-Based Stroke Diagnosis Making Global Prehospital Thrombolytic Treatment Possible

Persson

Fhager

Trefná

et al. 2014

IEEE Trans. Biomed. Eng.

312

247

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Section: Introductionmentioning

confidence: 99%

Microwave-Based Stroke Diagnosis Making Global Prehospital Thrombolytic Treatment Possible

Persson

Fhager

Trefná

et al. 2014

IEEE Trans. Biomed. Eng.

312

247

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“…The numerical phantom has relative permittivity of 78 in the inner layer and =53.53 in the outside layer. The relative permittivity of the physical phantom were 78.63 and 51.72 for inner and outer layer, respectively [10].…”

Section: Phantom Parameterizationmentioning

confidence: 99%

Comparison analysis between filtered back projection and algebraic reconstruction technique on microwave imaging

Ramadhan

Prabowo

Aprilliyani

et al. 2018

AIP Conference Proceedings

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Abstract. Victims of acute cancer and tumor are growing each year and cancer becomes one of the causes of human deaths in the world. Cancers or tumor tissue cells are cells that grow abnormally and turn to take over and damage the surrounding tissues. At the beginning, cancers or tumors do not have definite symptoms in its early stages, and can even attack the tissues inside of the body. This phenomena is not identifiable under visual human observation. Therefore, an early detection system which is cheap, quick, simple, and portable is essensially required to anticipate the further development of cancer or tumor. Among all of the modalities, microwave imaging is considered to be a cheaper, simple, and portable system method. There are at least two simple image reconstruction algorithms i.e. Filtered Back Projection (FBP) and Algebraic Reconstruction Technique (ART), which have been adopted in some common modalities. In this paper, both algorithms will be compared by reconstructing the image from an artificial tissue model (i.e. phantom), which has two different dielectric distributions. We addressed two performance comparisons, namely quantitative and qualitative analysis. Qualitative analysis includes the smoothness of the image and also the success in distinguishing dielectric differences by observing the image with human eyesight. In addition, quantitative analysis includes Histogram, Structural Similarity Index (SSIM), Mean Squared Error (MSE), and Peak Signal-to-Noise Ratio (PSNR) calculation were also performed. As a result, quantitative parameters of FBP might show better values than the ART.However, ART is likely more capable to distinguish two different dielectric value than FBP, due to higher contrast in ART and wide distribution grayscale level.

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“…A further study of dielectric spectroscopy of canine myocardium during acute ischaemic stroke using the frequency band from 100 KHz to 6 GHz demonstrated the ability to detect ischaemic from non-ischaemic tissues [85]. In 2003, Schmid et al [86] studied the dielectric properties of brain tissues from 10 male and 10 female humans measured less than 10 hours after death. The results showed that the electrical conductivity of the grey matter was higher than in the results based on animal brain samples and excised samples of human brain tissues measured more than 24 hours post-mortem [86].…”

Section: Dielectric Properties Of Human Tissues At Microwave Frequenciesmentioning

confidence: 99%

“…In 2003, Schmid et al [86] studied the dielectric properties of brain tissues from 10 male and 10 female humans measured less than 10 hours after death. The results showed that the electrical conductivity of the grey matter was higher than in the results based on animal brain samples and excised samples of human brain tissues measured more than 24 hours post-mortem [86].…”

Section: Dielectric Properties Of Human Tissues At Microwave Frequenciesmentioning

confidence: 99%

“…In another study, a plaster outer shell represented the skull, a gel was used for the grey matter, and a water-oil mixture was used for the white matter in a child's head phantom [118]. In [86], a square slice of materials consisting of different percentages of liquid paraffin, distilled water, Tween-20, sodium chloride, TX151 gelling agent, imidazolidinyl urea and p-hydroxybenzoic acid methyl-ester were used as a human head phantom.…”

Section: Breast Phantom For Planar Breast Imaging Systemmentioning

confidence: 99%

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Design and implementation of microwave imaging systems for medical applications

Mohammed¹

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A microwave medical imaging system processes scattered electromagnetic fields in the microwave region to create images. It is an alternative or complementary imaging tool that can be used in medical applications to assist the diagnosis of disease inside the human body. For example, microwave imaging offers many desirable characteristics as a cancer evaluation tool. It is a non-ionising radiation and during measurement, compression of the scanned body part is avoided. These benefits potentially lead to safer and more comfortable examinations. It also has the potential to be both sensitive and specific to detect small tumors, whilst being much lower cost than current methods, such as magnetic resonant imaging, positron emission tomography and ultrasound. However, it should be noted that all current imaging modalities have a relatively high incidence of false positive and false negative results. Moreover, microwave medical imaging designs can be made portable, so real time results for applications such as brain stroke detection is feasible.This thesis proposes several microwave medical imaging systems based on ultrawideband technology and in doing so makes five contributions to the field of microwave imaging systems. The first contribution is the development of a UWB slotted Vivaldi antenna that operates as the transducer for imaging systems. The antenna is compact structure to overcome the shortcoming of conventional Vivaldi tapered-slot antennas. The antennas have a stable main-beam direction and high dynamic range. They are designed to work efficiently in a coupling medium. The designed antennas provide high sensitivity and excellent time-domain characteristics to enhance the capability of the proposed imaging systems.The second contribution of the thesis is the development of coupling medium and artificial phantoms that emulate the electrical properties of realistic tissue in order to test and assess the proposed microwave imaging systems before application to human subject.Two types of coupling medium are described. A breast phantom and a head phantom are designed and fabricated. The materials of the fabricated phantoms mimic the electromagnetic features of realistic human tissues. The electrical characteristics of all the fabricated materials show excellent matching when compared with the available data on real human tissue.The third contribution of the thesis is the design of a microwave medical imaging system for breast cancer detection. A planar scanning system is developed. The laboratory assessment of a two-dimensional and three-dimensional imaged breast phantom is iii explained. An experimental study of the breast cancer detection employing a fabricated semi-rectangular shaped phantom is conducted. An image reconstruction algorithm is developed to generate the images of the breast phantom using the measurement data.The results show the ability of the designed microwave imaging system to detect and localise tumors at different locations of the breast phantom.The fourth contribution of the thesis ...

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Dielectric properties of human brain tissue measured less than 10 h postmortem at frequencies from 800 to 2450 MHz

Cited by 71 publications

References 13 publications

Microwave-Based Stroke Diagnosis Making Global Prehospital Thrombolytic Treatment Possible

Microwave-Based Stroke Diagnosis Making Global Prehospital Thrombolytic Treatment Possible

Comparison analysis between filtered back projection and algebraic reconstruction technique on microwave imaging

Design and implementation of microwave imaging systems for medical applications

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