| 1. |
- Asan, Noor Badariah, 1984-, et al.
(författare)
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Effect of Thickness Inhomogeneity in Fat Tissue on In-Body Microwave Propagation
- 2018
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Ingår i: Proceedings of the 2018 IEEE/MTT-S International Microwave Biomedical Conference (IMBIOC). - Philadelphia, USA : IEEE. - 9781538659182 ; , s. 136-138
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Konferensbidrag (refereegranskat)abstract
- In recent studies, it has been found that fat tissue can be used as a microwave communication channel. In this article, the effect of thickness inhomogeneities in fat tissues on the performance of in-body microwave communication at 2.45 GHz is investigated using phantom models. We considered two models namely concave and convex geometrical fat distribution to account for the thickness inhomogeneities. The thickness of the fat tissue is varied from 5 mm to 45 mm and the Gap between the transmitter/receiver and the starting and ending of concavity/convexity is varied from 0 mm to 25 mm for a length of 100 mm to study the behavior in the microwave propagation. The phantoms of different geometries, concave and convex, are used in this work to validate the numerical studies. It was noticed that the convex model exhibited higher signal coupling by an amount of 1 dB (simulation) and 2 dB (measurement) compared to the concave model. From the study, it was observed that the signal transmission improves up to 30 mm thick fat and reaches a plateau when the thickness is increased further.
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| 2. |
- Lee, Doojin, et al.
(författare)
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Monitoring of Healing Progression of Cranial Vault using One-dimensional Pulsed Radar Technique
- 2018
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Ingår i: Proceedings of the 2018 IEEE/MTT-S International Microwave Biomedical Conference (IMBioC). - : IEEE. - 9781538659182 ; , s. 64-66
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Konferensbidrag (refereegranskat)abstract
- In this paper, the skull healing after surgery has been investigated using proposed resistively loaded antenna utilizing the principles of short pulse radar technique. The one-dimensional pulsed profile for every stage has been demonstrated that the healing stages after craniotomy can be monitored by observing the change in the amplitude of the matched filter responses.
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| 3. |
- Redzwan, Syaiful, et al.
(författare)
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Initial in-vitro trial for intra-cranial pressure monitoring using subdermal proximity-coupled split-ring resonator
- 2018
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Ingår i: IMBioc 2018 - 2018 IEEE/MTT-S International Microwave Biomedical Conference. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538659182 ; , s. 73-75
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Konferensbidrag (refereegranskat)abstract
- Intra cranial pressure (ICP) monitoring is used in treating severe traumatic brain injury (TBI) patients. All current clinical available measurement methods are invasive presenting considerable social costs. This paper presents a preliminary investigation of the feasibility of ICP monitoring using an innovative microwave-based non-invasive approach. A phantom mimicking the dielectric characteristics of human tissues of the upper part of the head at low microwave frequencies is employed together to a proof-of-concept prototype based on the proposed approach consisting in a readout system and a sub-dermally implanted passive device, both based in split ring resonator techniques. This study shows the potential of our approach to detect two opposite pressure variation stages inside the skull. The employed phantom model needs to be improved to support finer variations in the pressure and better phantom parts, principally for the skull mimic and the loss tangent of all mimics.
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| 4. |
- Velander, Jacob, et al.
(författare)
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A Four-Layer Phantom for Testing In-Vitro Microwave-Based Sensing Approach in Intra-Cranial Pressure Monitoring
- 2018
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Ingår i: Proceedings Of The 2018 IEEE/MTT-S International Microwave Biomedical Conference (IMBioC). - : IEEE. - 9781538659182 ; , s. 49-51
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Konferensbidrag (refereegranskat)abstract
- Multi-layer phantoms in proofs of concept, designs and validations of both microwave-based biomedical sensing and imaging system are becoming popular means to facilitate in-vitro experiments. In addition, they can contribute significantly to reduce animal use in scientific experimentation. In this paper, we design and fabricate a four-layer phantom composed of skin, skull, cerebrospinal fluid and brain mimic tissues to work between 2 and 3 GHz. In addition, the phantom incorporates a mechanism to produce pressure variation between the cerebrospinal fluid and the brain mimic tissues. This phantom is used in an in-vitro experiment to test and validate a new approach which could sense intra-cranial pressure variations through a microwave-based reflection method. The similarity of the phantom's tissues with human tissues from the viewpoint of the microwave response is analyzed in comparison with data from Italian Institute of Applied Physics in Florence. We found good agreement for the dielectric constant (Rel. Err. < 13 % for 68% of significance) in skin, cerebrospinal fluid and brain mimic tissues. For the skin, we got also good agreement for the loss tangent (Rel. Err. < 11 % for 68% of significance). The skull mimic phantom was stiff enough, but even presenting considerable errors, it was still good enough for the experiment. In addition, the capability of the phantom to operate at different pressures is discussed.
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