Microwave Dielectric Sensing of Free-Flowing, Single, Living Cells in Aqueous Suspension
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Inductive coupling between the two resonators enabled separation of microfluidic chips from RF connectors and allowed for time-resolved continuous-wave measurements on flowing single cells via the coaxial ports of a dielectric-loaded microwave cavity. Analysis via an equivalent circuit model showed that the novel resonator assembly maintained the permittivity-dependent sensitivity of a split ring resonator while operating at quality factors >1000 with lossy aqueous media (typically ~1900). Using a microfluidic channel with a 300 x 300 μm cross section, at a water-loaded resonant amplitude of ~-22 dB at 0 dBm input power level, shifts in amplitude due to individual cells passing through the sensing region of up to -0.0015 dB were observed. Correlations between averaged amplitude shifts and cell size as well as material properties demonstrate the diagnostic potential of this technique.
Photovoltaic Power Harvesting Technologies in Biomedical Implantable Devices Considering the Optimal Location
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For example, current energy harvesters rely on piezoelectricity, thermoelectricity and solar electricity to drive the implantable device. However, the majority of these energy harvesting techniques suffer from a variety of limitations such as low power output, large size or poor efficiency. Due to their high efficiency, we focus our attention on solar photovoltaic cells. We demonstrate the tissue absorption losses severely influence their performance. We predict the performance of these cells using simulation through the verified experimental data. Our results show that our model can obtain 17.20% efficiency and 0.675 V open-circuit voltage in one sun condition. In addition, our device can also harvest up to 15 mW/ cm2in dermis and 11.84 mW/ cm2in hypodermis by using 100 mW/ cm2light source at 800 nm and 850 nm, respectively. We propose implanting our device in hypodermis to obtain a stable power output.
Comparison of Different Assessment Quantities to Evaluate Lead Electromagnetic Model for Radio Frequency Energy-Induced Heating
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The set included 32 single electrode leads with straight and helical wires. The LEMs were obtained and validated with 3D electromagnetic and thermal co-simulations at 128 MHz. A shift of the position of temperature or SAR sensor from the electrode tip to the electrode pedestal resulted in a decrease of the linear regression coefficient of determination for the LEM calibration factors. Behavior of different assessment quantities in terms of sensitivity of sensor location significantly varied between leads with the helical and straight wires. In conclusion, utilization of analysis made for generic leads with straight wire can be significantly misleading for the prediction of results for leads with helical wires.
Study and Suppression of Multipath Signals in a Non-Invasive Millimeter Wave Transmission Glucose Sensing System
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This paper studies the impact of these wave phenomena on the signals transmitted and received from a pair of antennas designed to sense glucose changes via changes in transmission through a sample. Numerical simulations and controlled experiments with glucose solutions demonstrate for the first time that unwanted signal contributions from mm surface waves along the tissue can dominate the received signals but can be reduced with the use of appropriately placed absorbers around the antenna sensors. As a result, the sensitivity of such a sensing system to glucose changes is increased. This finding can be very useful in the design and development of the glucose sensor under study, as well as for other EM-based diagnostic medical applications.
A Radiating System for Low Frequency Highly Focused Hyperthermia with Magnetic Nanoparticles
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Then, through an electromagnetic software based on the Method of Moments (MoM), we performed numerical simulations of the coil that resulted in excellent agreement with the experimental measurements conducted at the workbench on a fabricated prototype. After that, a radiating system consisting of the coil, a high-power radiofrequency signal generator and a set of magnetic nanoparticles have been set up. We carried out several experimental trials with different samples of magnetic nanoparticles in order to demonstrate the focusing property of the proposed system. The results we obtained suggested that a careful design of the radiating system could pave the way towards more efficient and safer magnetic hyperthermia treatments in clinical applications.
Design and Evaluation of Affective Virtual Reality System Based on Multimodal Physiological Signals and Self-Assessment Manikin
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Design elements including subject features, sound features, motion features and color features were extracted by referring to the referenced emotion materials, art works and the existing VR scenes. Affective VR scenes were then designed by Unreal Engine 4.12 and their effectiveness was validated by Self-Assessment Manikin (SAM). Furthermore, arousal was used as an indicator to compare the difference of ecological validity between VR and video emotional materials with an intergroup experiment through Electroencephalography (EEG), Heart Rate (HR), Galvanic Skin Response (GSR), and SAM. Results proved that VR scenes could achieve the same emotion elicitation as video. Especially, there was significant difference in measures of Fearful in SAM evaluation, indicating that VR emotion materials were expected to deliver a good effect on negative emotional scenes. The proposed AVRS as well as the multimodal physiological signal database with valence, arousal and dominance (VAD) labels could help the development of emotion related studies.
