Validation of Clausius-Mossotti Function in Wideband Single-Cell Dielectrophoresis
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The calculated lower crossover frequency was found to be in general agreement with the measured values of 28 ± 4 kHz. However, the calculated upper crossover frequency was significantly different from the measured values of 326 ± 35 MHz The difference can be attributed to the field being highly nonuniform in single-cell dielectrophoresis, especially at higher frequencies. Additionally, with closely spaced electrodes in singlecell dielectrophoresis, adhesive force may have to be considered even for a relatively nonadherent Jurkat cell. In any case, the difference between the calculated and measured crossover frequency suggests that the classical Clausius-Mossotti function, originally derived from the Maxwell-Wagner mixture model of a cell suspension, may not apply to single-cell dielectrophoresis in a straightforward manner, especially at high frequencies.
Design of a Microwave Global Endometrial Ablation Device
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For treating large cavities, conformal microwave radiation is achieved by coupling the loop antenna with a passive element. A 3D-coupled FEM electromagnetic and heat transfer simulator was employed to optimize the antenna geometry with the goal of maximizing return loss at the 915 MHz operating frequency, and achieving adequate ablation depths for a range of uterine cavity sizes. Proof-of-concept devices were fabricated and experimentally evaluated in ex vivo tissue. The simulated and measured return loss of the optimized design was 20 dB at 915 MHz. Experiments in ex vivo tissue demonstrated the ability of the presented device to achieve mean ablation depths of 7.3 mm. We demonstrated a technique for creating planar ablation patterns suitable for global endometrial ablation of different uterine cavity sizes by employing a loop antenna with a passive element. Our design provides a planar ablation pattern by using a loop antenna with a passive element that will allow for ablation applications not realizable with conventional coaxial monopole, dipole, and slot antennas.
Metamaterial Zeroth Order Resonator RF Coil for Human Head: Preliminary design for 10.5T MRI
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Simulation and experimental results are provided for an 8-channel M-ZOR based RF coil in comparison with a standard high performance 8-channel dipole based RF coil for the 10.5T MRI system. Each element is 18 cm long, identical, evenly spaced along the circumference of the cylindrical phantom, loaded with dielectric material, and referred to as inverted Metamaterial Zeroth Order Resonator. The resonator elements are open circuited, matched, and tuned to 447.06 MHz with the phantom. An unloaded to loaded Q-factor ratio of 2.97 is obtained from the scattering matrix of the proposed design. The length independent nature of the proposed design and the flexibility of the lumped elements have provided an optimized element with a substrate thickness of roughly 3 mm. With the proposed design, there is a similar RF magnetic field strength (B1+) to SAR ratio with a reduced 10g averaged SAR of 2.892 for the same input power compared to that of a dipole coil. This could make the coil acceptable for the clinical high-quality imaging.
Adaptive Radar-Based Human Activity Recognition with L1-Norm Linear Discriminant Analysis
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In contrast to standard LDA, L1-LDA exhibits resistance against outliers that may lie among the training data, e.g., due to mislabeling. We use real-data from four motion classes to experimentally compare the performance of the proposed methods with standard (L2-norm-based) LDA. The results corroborate that the proposed methods markedly outperform LDA when the training datasets are corrupted with mislabeling, while they provide similar performance under nominal training data.
UHF-Dielectrophoresis Crossover Frequency as a New Marker for Discrimination of Glioblastoma Undifferentiated Cells
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We demonstrate here that the presented dielectrophoresis electrokinetic method can be used to discriminate the undifferentiated from the differentiated cells. In this study, microfluidic lab-on-chip systems implemented on Bipolar-Complementary Oxide Semiconductor (BiCMOS) technology are used allowing single cell handling and analysis. Based on characterizations of their own intracellular features, both selected glioblastoma cell lines cultured in distinct culture conditions have shown clear differences of DEP crossover frequency signatures compared to differentiated cells cultured in normal medium. These results support the concept and validate the technique efficiency for cell characterization in glioblastoma pathology.
Dual-Band Antenna Design for Wireless Capsule Endoscopic Image Transmission in the MHz Band Based on Impulse Radio Technology
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The proposed antennas can be fed by a battery-powered impulse radio (IR) transceiver that contains five signal peaks in the MHz band, and two signal peaks (38.5 and 57.6 MHz) are selected for antenna design to realize dual-band communication with higher data rates. Dimensions of the transmitting antenna and the receiving antenna are π ×(5.5)2 × 2mm3 and π ×(40)2 × 4.8mm3, respectively. The antenna distance that satisfies the WCE medical image transmission requirements is roughly estimated by the received powerfrom the transceiver. With the antenna distance of 50 mm, the attenuation is 33 and 47 dB at 38.5 and 57.6 MHz, respectively. With the antenna distance of 100 mm, the attenuation is 39 and 59 dB at 38.5 and 57.6 MHz, respectively. It can be estimated thatproposed antennas can realize a total data rate of 2.5 Mbps within 100 mm antenna distance if two antennas are aligned, or within 50 mm antenna distance if two antennas are misaligned to 60 mm.
