Measuring and analysing vibration motors in insoles via accelerometers

Purpose: Falling is a major public health concern among elderly people, and they often cause serious injuries1,2. They most frequently occur during walking and are associated with the chronic deterioration in the neuromuscular and sensory systems, as well as with ankle muscle weakness and lower endurance of these muscles to fatigue1,3. Vibrating insoles, providing a subsensory mechanical noise signal to the plantar side of the feet, may improve balance in healthy young and older people and in patients with stroke or diabetic neuropathy4. The object of this study is to find the most suitable vibrator to put into the insole which can effectively improve the balance control of the elderlies. Method: We choose three different vibration actuators (micro vibration motor, brushless motor and eccentric motor) with two different weights on the insole. First, we put three same motors and two accelerometers on the insole, as shown in Figure1, then attach another layer on both side of the insole. Second, connect the motors to the power supply and the accelerometer to NI PXI-1033 spectrum analyzer which is used to collect the accelerometers' data. At last, using Fast Fourier Transform (FFT) to analyze and compare the results to see which motor is the most stable and suitable to put into the insole. Results & Discussion: The results showed that the most stable one is the brushless motor. The reason why the frequency is stable is that the relationship between voltage and frequency is linear, and the error is small through continuous measurements. On the other hand, when a person weight 55 kg stands on the insole, the frequency isn't affected by the weight. These two results appear very similar to each other, as shown in Figure 2. According to the result, we use the brushless motor to be our vibrator in the insole, and hope this will help the elderlies improve their balance control ability more efficiency

Microstructural dependency of optical properties of m -plane InGaN multiple quantum wells grown on 2° misoriented bulk GaN substrates

A non-polar m-plane structure consisting of five InGaN/GaN quantum wells (QWs) was grown on ammonothermal bulk GaN by metal-organic vapor phase epitaxy. Surface step bunches propagating through the QW stack were found to accommodate the 2° substrate miscut towards the -c direction. Both large steps with heights of a few tens of nanometres and small steps between one and a few atomic layers in height are observed, the former of which exhibit cathodoluminescence at longer wavelengths than the adjacent m-plane terraces. This is attributed to the formation of semi-polar facets at the steps on which the QWs are shown to be thicker and have higher Indium contents than those in the adjacent m-plane regions. Discrete basal-plane stacking faults (BSFs) were occasionally initiated from the QWs on the main m-plane terraces, but groups of BSFs were frequently observed to initiate from those on the large steps, probably related to the increased strain associated with the locally higher indium content and thickness.This project is funded by the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no 279361 (MACONS) and in part by the EPSRC (Grant Nos. EP/H047816/1 and EP/J001627/1).This is the author accepted manuscript. The final version is available from AIP via http://dx.doi.org/10.1063/1.492872

Cellular uptake and imaging studies of gadolinium-loaded single-walled carbon nanotubes

postprintThe 18th Joint Annual Meeting of ISMRM-ESMRMB, Stockholm, Sweden, 1-7 May 2010

Silicon-based III-V quantum-dot laser for silicon photonics

Monolithic III-V materials grown on Si is a promising platform for silicon photonics. Here, by investigating the laser performance of two conventional III-V quantum structures on Si, namely quantumdots and quantum-well, we unambiguously demonstrate the excellence and suitability of quantum-dots over quantum-well in silicon-based laser structure and reveal the physical mechanisms underneath, which is attributed to the better tolerance characteristic of quantum-dots for optically detrimental defects. Our work shows that monolithic III-V quantum-dot lasers on Si are the most promising light source for silicon photonics technology

A targeting microbubble for ultrasound molecular imaging

Microbubbles conjugated with targeting ligands are used as contrast agents for ultrasound molecular imaging. However, they often contain immunogenic (strept)avidin, which impedes application in humans. Although targeting bubbles not employing the biotin-(strept)avidin conjugation chemistry have been explored, only a few reached the stage of ultrasound imaging in vivo, none were reported/evaluated to show all three of the following properties desired for clinical applications: (i) low degree of non-specific bubble retention in more than one non-reticuloendothelial tissue; (ii) effective for real-time imaging; and (iii) effective for acoustic quantification of molecular targets to a high degree of quantification. Furthermore, disclosures of the compositions and methodologies enabling reproduction of the bubbles are often withheld.To develop and evaluate a targeting microbubble based on maleimide-thiol conjugation chemistry for ultrasound molecular imaging.Microbubbles with a previously unreported generic (non-targeting components) composition were grafted with anti-E-selectin F(ab')2 using maleimide-thiol conjugation, to produce E-selectin targeting microbubbles. The resulting targeting bubbles showed high specificity to E-selectin in vitro and in vivo. Non-specific bubble retention was minimal in at least three non-reticuloendothelial tissues with inflammation (mouse heart, kidneys, cremaster). The bubbles were effective for real-time ultrasound imaging of E-selectin expression in the inflamed mouse heart and kidneys, using a clinical ultrasound scanner. The acoustic signal intensity of the targeted bubbles retained in the heart correlated strongly with the level of E-selectin expression (|r|≥0.8), demonstrating a high degree of non-invasive molecular quantification.Targeting microbubbles for ultrasound molecular imaging, based on maleimide-thiol conjugation chemistry and the generic composition described, may possess properties (i)-(iii) desired for clinical applications

Single-mode photonic crystal nanobeam lasers monolithically grown on Si for dense integration

Ultra-compact III-V nanolasers monolithically integrated on Si with ultra-low energy consumption and small modal volume have been emerged as one of the most promising candidates to achieve Si on-chip light sources. However, the significant material dissimilarities between III-V and Si fundamentally limit the performance of Si-based III-V nanolasers. In this work, we report 1.3 m InAs/GaAs quantum-dot photonic-crystal (PhC) nanobeam lasers directly grown on complementary metal-oxide-semiconductor compatible on-axis Si (001) substrates. The continuous-wave optically pumped PhC nanobeam lasers exhibited a single-mode operation, with an ultra-low lasing threshold of ~ 0.8 W at room temperature. In addition, a nanoscale physical volume of ~ 8 0.53 0.36 m3 (~ 25 (n1)3) was realized through a small number of air-holes in PhC nanobeam laser. The promising characteristics of the PhC nanobeam lasers with small footprint and ultra-low energy consumption show their advanced potential towards densely integrated Si photonic integrated circuits

结合遗传算法的LVQ神经网络在声学底质分类中的应用

Author name used in this publication: 唐秋华Author name used in this publication: 刘保华Author name used in this publication:Author name used in this publication: 陈永奇Author name used in this publication: 周兴华Author name used in this publication: 丁继胜Title in Traditional Chinese: 結合遺傳算法的LVQ神經網絡在聲學底質分類中的應用Journal title in Traditional Chinese: 地球物理學報2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Towards an Intraoral-Based Silent Speech Restoration System for Post-laryngectomy Voice Replacement

© Springer International Publishing AG 2017, Silent Speech Interfaces (SSIs) are alternative assistive speech technologies that are capable of restoring speech communication for those individuals who have lost their voice due to laryngectomy or diseases affecting the vocal cords. However, many of these SSIs are still deemed as impractical due to a high degree of intrusiveness and discomfort, hence limiting their transition to outside of the laboratory environment. We aim to address the hardware challenges faced in developing a practical SSI for post-laryngectomy speech rehabilitation. A new Permanent Magnet Articulography (PMA) system is presented which fits within the palatal cavity of the user’s mouth, giving unobtrusive appearance and high portability. The prototype is comprised of a miniaturized circuit constructed using commercial off-the-shelf (COTS) components and is implemented in the form of a dental retainer, which is mounted under roof of the user’s mouth and firmly clasps onto the upper teeth. Preliminary evaluation via speech recognition experiments demonstrates that the intraoral prototype achieves reasonable word recognition accuracy and is comparable to the external PMA version. Moreover, the intraoral design is expected to improve on its stability and robustness, with a much improved appearance since it can be completely hidden inside the user’s mouth

基于自组织神经网络的声学底质分类研究

Author name used in this publication: 唐秋华Author name used in this publication: 刘保华Author name used in this publication: 陈永奇Author name used in this publication: 周兴华Author name used in this publication: 丁继胜Title in Traditional Chinese: 基于自組織神經網絡的聲學底質分類研究Journal title in Traditional Chinese: 聲學技術2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Nanostructured 3D Constructs Based on Chitosan and Chondroitin Sulphate Multilayers for Cartilage Tissue Engineering

Nanostructured three-dimensional constructs combining layer-by-layer technology (LbL) and template leaching were processed and evaluated as possible support structures for cartilage tissue engineering. Multilayered constructs were formed by depositing the polyelectrolytes chitosan (CHT) and chondroitin sulphate (CS) on either bidimensional glass surfaces or 3D packet of paraffin spheres. 2D CHT/CS multi-layered constructs proved to support the attachment and proliferation of bovine chondrocytes (BCH). The technology was transposed to 3D level and CHT/CS multi-layered hierarchical scaffolds were retrieved after paraffin leaching. The obtained nanostructured 3D constructs had a high porosity and water uptake capacity of about 300%. Dynamical mechanical analysis (DMA) showed the viscoelastic nature of the scaffolds. Cellular tests were performed with the culture of BCH and multipotent bone marrow derived stromal cells (hMSCs) up to 21 days in chondrogenic differentiation media. Together with scanning electronic microscopy analysis, viability tests and DNA quantification, our results clearly showed that cells attached, proliferated and were metabolically active over the entire scaffold. Cartilaginous extracellular matrix (ECM) formation was further assessed and results showed that GAG secretion occurred indicating the maintenance of the chondrogenic phenotype and the chondrogenic differentiation of hMSCs