ELECTROMAGNETIC ANALYSIS OF A NON-INVASIVE 3D PASSIVE MICROWAVE IMAGING SYSTEM - Abstract

Karanasiou, Irene S.; Uzunoglu, N.K.; Garetsos, A.

doi:10.1163/156939304323085793

Cited by 10 publications

(1 citation statement)

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“…Researchers are trying to resolve this subject from different perspectives. From bio-electromagnetic point of view, the skin-depth (δ), which characterizes the penetration of electromagnetic fields inside human head, is an important issue for this non-invasive imaging application [50]. As δ is inversely proportional to the frequency, it is widely known that operating at microwave frequencies provides increased depth of penetration due to low signal attenuation [51].…”

Section: Challenges Of Wideband Microwave Imagingmentioning

confidence: 99%

Wideband microwave imaging system for brain injury diagnosis

Mobashsher¹

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Brain injury is a major cause of disability and mortality worldwide. This medical emergency occurs when the brain is damaged as a result of various traumatic and non-traumatic incidences including accidents, strokes, drug abuses, tumours, infections and various diseases. As the devastating disorder of brain injury deteriorates rapidly, fast diagnosis and management is critically important for the treatment and recovery of the affected patient. Therefore, on-the-spot accurate detection by means of head imaging is the governing factor of the timely medication to ensure complete recovery of the injured patient. Although some existing imaging technologies, like CT and MRI, are capable for brain injury diagnosis, they are time-consuming, expensive, bulky and mostly stationary. Thus they cannot be carried by first response paramedic teams for the diagnosis purpose or be used for monitoring the patient to observe concurrent brain injury over periods of time without moving the patient. A compact and mobile technology that can be applied to monitor the patient continuously in real time, either at the bedside or in emergency room, would be a significant advantage comparing to the existing imaging techniques. This thesis aims to develop wideband microwave imaging systems for brain injury diagnosis and in doing so makes seven main contributions to the field of microwave imaging systems.As the efficacy of the microwave imaging systems relies on the sensing antennas, emphasize is given in the developments of compact, wideband antennas with directional radiation patterns for low microwave frequencies, which is the first contribution of this thesis. Three-dimensional (3D) antennas are proposed relying on multiple folding and slot-loading techniques. Nevertheless, a novel generalized miniaturization technique is proposed for compact antennas. The antennas are found to be efficient in both near-and far-fields for both frequency-and time-domain characterizations.The second contribution is the development of artificial human head phantom with realistic heterogeneous tissue distributions and actual wideband frequency-dispersive dielectric properties.The phantom is fabricated from artificial tissue emulating materials which are contained and structured by using 3D printed structures and castes. This realistic 3D human head phantom significantly improves the reliability of the experimental validation process of wideband microwave imaging compared to the reported validations with existing simple and stylized head phantoms.The contribution third contribution is the performance comparison of directional and omni-directional antennas for wideband microwave head imaging systems. A novel near-field time-domain characterization technique is proposed that enables the comparative analysis of antennas for nearfield applications. Application of this technique demonstrates that for microwave imaging systems directional antennas are more effective than omni-directional antennas. In terms of imaging performance, it is observed that directio...

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Section: Challenges Of Wideband Microwave Imagingmentioning

confidence: 99%

Wideband microwave imaging system for brain injury diagnosis

Mobashsher¹

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A W-band detector with high tangential signal sensitivity and voltage sensitivity

Xie

Zhang

Yang

et al. 2010

2010 International Conference on Microwave and Millimeter Wave Technology

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The Inverse Problem of a Passive Multiband Microwave Intracranial Imaging Method

Karanasiou

Uzunoglu

2005

2005 IEEE Engineering in Medicine and Biology 27th Annual Conference

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A novel Microwave Radiometry Imaging System (MiRaIS) has been developed and experimentally tested for feasible brain activation "remote" imaging via contactless measurements. The technique implemented, is focused microwave radiometry with the use of an ellipsoidal conductive wall cavity for focusing and a sensitive radiometric receiver for the detection of the brain conductivity and temperature variation. All system attributes in terms of spatial resolution and detection depth have been theoretically calculated. Phantom experimentation as well as human tests using single frequency receivers, have shown promising outcome concerning the potential clinical value of the proposed system, which seems to be able to pick-up brain activation, possibly caused by cortex conductivity changes. Following this research, a four-frequency radiometric receiver with a broadband antenna operating within the range 1.3-3.1GHz has been recently developed. In the present paper, a method for retrieving the conductivity variation profile detected in the above mentioned frequencies is discussed. The inverse problem solution is in detail addressed and indicative measurements are used for the validation of the solution in question. The latter represents the estimation of the conductivity variation of cortical areas, corresponding to the detection depth and spatial resolution predicted by the forward problem solution.

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ELECTROMAGNETIC ANALYSIS OF A NON-INVASIVE 3D PASSIVE MICROWAVE IMAGING SYSTEM - Abstract

Cited by 10 publications

References 0 publications

Wideband microwave imaging system for brain injury diagnosis

Wideband microwave imaging system for brain injury diagnosis

A W-band detector with high tangential signal sensitivity and voltage sensitivity

The Inverse Problem of a Passive Multiband Microwave Intracranial Imaging Method

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