53 research outputs found

    Design of a Dual-Band On-Body Antenna for a Wireless Body Area Network Repeater System

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    A dual-band on-body antenna for a wireless body area network repeater system is proposed. The designed dual-band antenna has the maximum radiation directed toward the inside of the human body in the medical implantable communication service (MICS) band in order to collect vital information from the human body and directed toward the outside in the industrial, scientific, and medical (ISM) band to transmit that information to a monitoring system. In addition, the return loss property of the antenna is insensitive to human body effects by utilizing the epsilon negative zeroth-order resonance property

    Heterogeneity of Skin Surface Oxygen Level of Wrist in Relation to Acupuncture Point

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    The distribution of partial oxygen pressure (pO2) is analyzed for the anterior aspect of the left wrist with an amperometric oxygen microsensor composed of a small planar Pt disk-sensing area (diameter = 25 μm). The pO2 levels vary depending on the measurement location over the wrist skin, and they are systematically monitored in the analysis for both one-dimensional single line (along the wrist transverse crease) and two-dimensional square area of the wrist region. Relatively higher pO2 values are observed at certain area in close proximity to the position of acupuncture points with statistical significance, indicating strong relationship between oxygen and acupuncture point. The used oxygen microsensor is sensitive enough to detect the pO2 variation depending on the location. This study may provide information helpful to understand possible physiological roles of the acupuncture points

    Deep Learning-based Synthetic High-Resolution In-Depth Imaging Using an Attachable Dual-element Endoscopic Ultrasound Probe

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    Endoscopic ultrasound (EUS) imaging has a trade-off between resolution and penetration depth. By considering the in-vivo characteristics of human organs, it is necessary to provide clinicians with appropriate hardware specifications for precise diagnosis. Recently, super-resolution (SR) ultrasound imaging studies, including the SR task in deep learning fields, have been reported for enhancing ultrasound images. However, most of those studies did not consider ultrasound imaging natures, but rather they were conventional SR techniques based on downsampling of ultrasound images. In this study, we propose a novel deep learning-based high-resolution in-depth imaging probe capable of offering low- and high-frequency ultrasound image pairs. We developed an attachable dual-element EUS probe with customized low- and high-frequency ultrasound transducers under small hardware constraints. We also designed a special geared structure to enable the same image plane. The proposed system was evaluated with a wire phantom and a tissue-mimicking phantom. After the evaluation, 442 ultrasound image pairs from the tissue-mimicking phantom were acquired. We then applied several deep learning models to obtain synthetic high-resolution in-depth images, thus demonstrating the feasibility of our approach for clinical unmet needs. Furthermore, we quantitatively and qualitatively analyzed the results to find a suitable deep-learning model for our task. The obtained results demonstrate that our proposed dual-element EUS probe with an image-to-image translation network has the potential to provide synthetic high-frequency ultrasound images deep inside tissues.Comment: 10 pages, 9 figure

    A Novel Incisionless Disposable Vaginal Device for Female Stress Urinary Incontinence: Efficacy and Quality of Life

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    Purpose This clinical study sought to evaluate the possible clinical effectiveness and practicality of URINO, an innovative, incisionless, and disposable intravaginal device, designed for patients suffering from stress urinary incontinence. Methods A prospective, multicenter, single-arm clinical trial was carried out, involving women diagnosed with stress urinary incontinence who used a self-inserted, disposable intravaginal pessary device. Comparisons were made between the results of the 20-minute pad-weight gain (PWG) test at baseline and visit 3, where the device was applied. After 1 week of device usage, compliance, satisfaction, the sensation of a foreign body, and adverse events were assessed. Results Out of 45 participants, 39 completed the trial and expressed satisfaction within the modified intention-to-treat group. The average 20-minute PWG of participants was 17.2±33.6 g at baseline and significantly dropped to 5.3±16.2 g at visit 3 with device application. A total of 87.2% of participants exhibited a reduction ratio of PWG by 50% or more, surpassing the clinical trial success benchmark of 76%. The mean compliance was recorded as 76.6%±26.6%, the average visual analogue scale score for patient satisfaction was 6.4±2.6, and the sensation of a foreign body, measured on a 5-point Likert scale, was 3.1±1.2 after 1 week of device use. No serious adverse events were reported; there was 1 instance of microscopic hematuria and 2 cases of pyuria, all of which recovered. Conclusions The investigated device demonstrated significant clinical effectiveness and safety for patients with stress urinary incontinence. It was easy to use, showing favorable patient compliance. We propose that these disposable intravaginal pessaries could potentially be an alternative treatment for patients with stress urinary incontinence who are seeking nonsurgical options or are unable to undergo surgery. Trial Registration The study was registered as a clinical trial (KCT0008369)

    A Lead-Free Piezoelectric Fiber Generator with a High Energy Conversion Constant Material

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    This paper introduces a fiber generator using PVDF with a high-performance lead-free piezoelectric ceramic as filler. The piezoelectric ceramic filler was Ba0.84Ca0.16Ti0.90Zr0.10O3 + CuO 0.25 wt% (BCTZC0.25) sintered at 1550 °C. The BCTZC0.25 has an improved high-energy conversion constant (d33 × g33). The fiber generator made of PVDF/BCTZC0.25 composite fiber showed 1.6 times better piezoelectric power generation performance compared to a pure PVDF fiber generator. The PVDF/BCTZC0.25 fiber generator produced an output voltage of 1.9 V at 4 Hz. Hence, we successfully demonstrated that a composite fiber generator that uses piezoelectric ceramics which are harmless to the human body can outperform a pure PVDF fiber generator

    Analysis of Dispersion of Carbon Nanotubes in <i>m</i>-Cresol

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    We analyzed the dispersion state of carbon nanotubes (CNTs) in m-cresol using dispersion stability analysis, optical microscopy, and UV-vis spectroscopy. The high dispersion stability of CNT/m-cresol dispersion was observed when it was sufficiently treated with ultrasonication. Despite the high dispersion stability, optical microscopy and UV-vis spectroscopy analysis of various CNT/m-cresol dispersions revealed that CNT bundles in m-cresol were not dispersed into individual CNTs. We also propose that the blue-shift of the G peak of CNTs in m-cresol in the Raman spectrum, which had been reported as evidence of the formation of the charge-transfer complex between m-cresol and CNTs, is rather attributed to the interference of m-cresol’s inherent peak at around 1600 cm−1

    Virtual Coupling of Railway Vehicles: Gap Reference for Merge and Separation, Robust Control, and Position Measurement

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    Virtual coupling, which refers to the operation of railway vehicles that enables the merge and separation of vehicles on the move by controlling the gap between the vehicles without any mechanical coupling, is one of the technologies for increasing the transport capacity and enhancing operational efficiency. This paper proposes a robust gap controller based on sliding mode control with a nonlinear train model with uncertainties. Additionally, a gap reference generation scheme is developed that ensures that the merge and separation of two trains is completed before a given location and respects constraints on acceleration and jerk. The position and velocity measurement errors arising from imperfect knowledge of wheel diameters are also considered, and a new error correction scheme is proposed to reduce the perturbation in the gap control performance. The proposed schemes are validated through simulations.FALS

    Investigation of shear-induced rearrangement of carbon nanotube bundles using Taylor-Couette flow

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    Macroscopic assemblies of carbon nanotubes (CNTs) usually have a poor alignment and a low packing density due to their hierarchical structure. To realize the inherent properties of CNTs at the macroscopic scale, the CNT assemblies should have a highly aligned and densified structure. Shear-aligning processes are commonly employed for this purpose. This work investigates how shear flows affect the rearrangement of CNT bundles in macroscopic assemblies. We propose that buckling behavior of CNT bundles in a shear flow causes the poor alignment of CNT bundles and a low packing density of CNT assemblies; the flow pattern and the magnitude of shear stress induced by the flow are key factors to regulate this buckling behavior. To obtain CNT assemblies with a high packing density, the CNTs should undergo a laminar flow that has a sufficiently low shear stress. Understanding the effect of shear flow on the structure of CNT bundles may guide improvement of fabrication strategies.11Ysciescopu

    Synthesis of single-walled carbon nanotubes using hemoglobin-based iron catalyst

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    Hemoglobin (Hb) was used as a catalyst for the growth of single-walled carbon nanotubes (SWCNTs). Hb was deposited onto a hydrophilic treated substrate by spin coating method. After oxidation at 800 C, protein chains were decomposed and iron oxide nanoparticles remained with an average diameter of 2.29 nm. High quality SWCNTs were synthesized with an average diameter of 1.22 nm. The protein chains prevent iron atoms aggregation and so the size of the nanoparticles is smaller than that from ferritin-like proteins. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.X1134sciescopu
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