673 research outputs found

    Tactile graphical display for the visually impaired information technology applications

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    This paper presents an interactive tactile graphical display, for the visually impaired information technology access applications. The display consists of a matrix of dots. Each dot is an electro rheological micro actuator. The actuator design and development process is presented in this paper. Prototype size 124x4 dots was manufactured. An advanced software tools and embedded system based on voltage matrix manipulation has been developed, to provide the display near real time control. The experimental tests carried out into the developed prototype showed that each actuator of the matrix was able to provide a vertical movement of 0.7 mm and vertical holding force of 100 to 200 mN. The stroke and dynamic response tests showed the practicability of the developed tactile display, for the visually impaired information technology applications

    Anorectal motility in patients with achalasia of the esophagus: recognition of an esophago-rectal syndrome

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    BACKGROUND: During my study of constipation, I encountered patients who had achalasia of the esophagus (AE) as well. The possibility of an existing relationship between the 2 conditions was studied. METHOD: Investigations to study the anorectal motility in 9 AE patients included: the intestinal transit time, anorectal manometry, rectoanal inhibitory reflex, defecography and electromyography (EMG) of external anal sphincter and levator ani muscle. Anorectal biopsy was done. The study comprised 8 healthy volunteers as controls. RESULTS: 6/9 AE patients had constipation presenting as strainodynia (excessive prolonged straining at stool). Rectocele was present in 4 of them. The 6 constipated patients showed significantly high rectal neck pressure (p < 0.05), absent rectoanal inhibitory reflex and aganglionosis in the anorectal biopsy. The EMG revealed diminished activity in 4 of the 6 constipated patients. The remaining 3 patients with AE had normal anorectal function. Heller's myotomy with Nissen's fundoplication improved the dysphagia, but not the constipation which was, however, relieved after performance of anorectal myectomy. CONCLUSION: The high incidence of constipation with AE postulates a relationship between the 2 conditions. Both have the same pathologic lesion which is aganglionosis. This study is preliminary and requires further studies on a larger number of patients

    Run-time Energy and Time Management for Intermittent LoRaWAN Communications

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    Intermittent computing, utilising non-volatile memory (NVM) to maintain system state during power outages, addresses the unpredictability of energy harvesting (EH) in Internet of Things (IoT) systems. However, challenges persist, notably in ensuring energy-aware task-based operations and accurate timekeeping during system shutdowns, which impede real-time data collection. To address this, the paper presents an energy and time management unit (ETMU) for intermittent systems, which facilitates task-based operations and timekeeping capabilities using multi-harvest energy sources. This ETMU adjusts energy storage and operating voltage at run-time, meeting the energy needs of specific tasks and startup times while preserving crucial system information during power outages. Furthermore, this ETMU incorporates an ultra-low power real-time clock (RTC), ensuring independent and accurate timekeeping during system power outages.The proposed ETMU is integrated into an intermittent system designed for ultrasonic water flow measurements to demonstrate its functionality. This system incorporates three energy harvesters and utilizes the LoRaWAN communication protocol for data transmission and time synchronization. Experimental results demonstrate the efficient management of intermittent LoRaWAN communications and precise timekeeping for data collection

    Treadmill Platform for Quadrupedal Robots

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    Cal Poly Legged Robots, led by Professor Refvem and Professor Xing, has been leading Cal Poly’s attempts to simulate, produce, and test their legged robots. The initial testing of the locomotion of these robots can be dangerous to the robot since any bugs in the code could cause the robot to fall over and harm itself. Our responsibility as a team was to deliver a portable platform for testing the locomotion capabilities containing a fall prevention mechanism. In short, we have designed a platform for this purpose that consists of a treadmill surrounded by a wheeled chassis with a system of ropes, pulleys, and a winch for a fall prevention mechanism. Our method of lifting the robot is a success in two ways. First, our method only requires the addition of four eyebolts to the robot, a rather minor modification. Second, our method does not impede the motion of the robot when it is running normally. However, it was found that our method requires 1-1.7 seconds to lift the robot (depending on where the robot is located on the treadmill) – a rather crippling amount of time to lift a robot, seeing as how it is desired for the robot to run at 8 mph on the treadmill. Regardless, our design provides a great starting point for future Senior Project teams to improve upon it. It is our hope that our design will allow Cal Poly Legged Robots to further the development of legged robots and to generate interest, both at Cal Poly and hopefully around the world, in this area of study

    A New Servo Control Drive for Electro Discharge Texturing System Industrial Applications Using Ultrasonic Technology

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    This paper presents a new ultrasonic servo control drive for electro discharge texturing system industrial applications. The new drive is aiming to overcome the current teething issues of the existing electro discharge texturing system, servo control drive level of precision, processing stability, dynamic response and surface profile of the machined products. The new ultrasonic servo control drive consists of three main apparatuses, an ultrasonic motor, electronic driver and control unit. The ultrasonic motor consists of three main parts, the stator, rotor and sliding element. The motor design process, basic configuration, principles of motion, finite element analysis and experimental examination of the main characteristics is discussed in this paper. The electronic driver of the motor consists of two main stages which are the booster and piezoelectric amplifier. The experimental test and validation of the developed servo control drive in electro discharge texturing platform is also discussed and presented in this paper. The initial results showed that the ultrasonic servo control drive is able to provide: a bidirectional of motion, a resolution of &lt;50μm and a dynamic response of &lt;10msec. The electron microscopic micro examination into the textured samples showed that: a clear improvement in machining stability, products surface profile, a notable reduction in the processing time, arcing and short-circuiting teething phenomena

    An Innovative 3D Ultrasonic Actuator with Multidegree of Freedom for Machine Vision and Robot Guidance Industrial Applications Using A Single Vibration Ring Transducer

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    This paper presents an innovative 3D piezoelectric ultrasonic actuator using a single flexural vibration ring transducer, for machine vision and robot guidance industrial applications. The proposed actuator is principally aiming to overcome the visual spotlight focus angle of digital visual data capture transducer, digital cameras and enhance the machine vision system ability to perceive and move in 3D. The actuator Design, structures, working principles and finite element analysis are discussed in this paper. A prototype of the actuator was fabricated. Experimental tests and measurements showed the ability of the developed prototype to provide 3D motions of Multidegree of freedom, with typical speed of movement equal to 35 revolutions per minute, a resolution of less than 5μm and maximum load of 3.5 Newton. These initial characteristics illustrate, the potential of the developed 3D micro actuator to gear the spotlight focus angle issue of digital visual data capture transducers and possible improvement that such technology could bring to the machine vision and robot guidance industrial applications

    On the pathogenesis of penile venous leakage: role of the tunica albuginea

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    <p>Abstract</p> <p>Background</p> <p>Etiology of venogenic erectile dysfunction is not exactly known. Various pathologic processes were accused but none proved entirely satisfactory. These include presence of large venous channels draining corpora cavernosa, Peyronie's disease, diabetes and structural alterations in fibroblastic components of trabeculae and cavernous smooth muscles. We investigated hypothesis that tunica albuginea atrophy with a resulting subluxation and redundancy effects venous leakage during erection.</p> <p>Methods</p> <p>18 patients (mean age 33.6 ± 2.8 SD years) with venogenic erectile dysfunction and 17 volunteers for control (mean age 31.7 ± 2.2 SD years) were studied. Intracorporal pressure was recorded in all subjects; tunica albuginea biopsies were taken from 18 patients and 9 controls and stained with hematoxylin and eosin and Masson's trichrome stains.</p> <p>Results</p> <p>In flaccid phase intracorporal pressure recorded a mean of 11.8 ± 0.8 cm H<sub>2</sub>O for control subjects and for patients of 5.2 ± 0.6 cm, while during induced erection recorded 98.4 ± 6.2 and 5.9 ± 0.7 cmH<sub>2</sub>O, respectively. Microscopically, tunica albuginea of controls consisted of circularly-oriented collagen impregnated with elastic fibers. Tunica albuginea of patients showed degenerative and atrophic changes of collagen fibers; elastic fibers were scarce or absent.</p> <p>Conclusion</p> <p>Study has shown that during erection intracorporal pressure of patients with venogenic erectile dysfunction was significantly lower than that of controls. Tunica albuginea collagen fibers exhibited degenerative and atrophic changes which presumably lead to tunica albuginea subluxation and floppiness. These tunica albuginea changes seem to explain cause of lowered intracorporal pressure which apparently results from loss of tunica albuginea veno-occlusive mechanism. Causes of tunica albuginea atrophic changes and subluxation need to be studied.</p

    NEW FLAVONOIDS FROM THE AERIAL PARTS OF POLYGONUM EQUISETIFORME SM (POLYGONACEAE)

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    Objective: The current study was to deal the isolation and identification of secondary metabolites from Polygonum equisetiforme and evaluation of antioxidant activity of its extract.Methods: The methanol-water extract (7:3) of the air-dried aerial parts of Polygonum equisetiforme was fractionated and separated to obtain the isolated compounds by different chromatographic techniques. Structures of these compounds were elucidated by UV and 1Dâ„2D Hâ„ C NMR spectroscopy and compared with the literature data. The crude extract was evaluated for in vitro antioxidant activity using the 2,2 diphenyl dipicryl hydrazine (DPPH) method.Results: Ten secondary metabolites were isolated from Polygonum equisetiforme in this study. Of which three new flavonoids named as 3,5,7,2',5' pentahydroxyflavone 3-O-b-D-glucopyranoside (1), 3,5,7,2',5' pentahydroxyflavone 3-O-b-D-glucopyranoside 8 C-sulphated (2) and quercetin 3-O-β-D-glucucorinde 6''-methyl ester 8-sulphated (3) as well as quercetin 3-O-β-D-glucucorinde methyl ester (4), quercetin 3-O-β-D-glucopyranoside (5), quercetin 7-O-β-D-glucopyranoside (6), quercetin(7), myricetin (8), P-methoxy gallic acid methyl ester (9) and gallic acid (10). The antioxidant potential of P. equisetiforme extract was evaluated by investigating it's total phenolic and flavonoid content and DPPH radical scavenging activity whereby the extract showed significant antioxidant activity (IC50 = 37.45 μg/ml). The total phenolic and flavonoid content was found to be 130.79±5.502 and 45.8±1.63 μg/ml, respectively.Conclusion: Polygonum equisetiforme is a promising medicinal plant, and our study tends to support the therapeutic value of this plant as an antioxidant drug

    Abnormal expression of p27kip1 protein in levator ani muscle of aging women with pelvic floor disorders – a relationship to the cellular differentiation and degeneration

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    BACKGROUND: Pelvic floor disorders affect almost 50% of aging women. An important role in the pelvic floor support belongs to the levator ani muscle. The p27/kip1 (p27) protein, multifunctional cyclin-dependent kinase inhibitor, shows changing expression in differentiating skeletal muscle cells during development, and relatively high levels of p27 RNA were detected in the normal human skeletal muscles. METHODS: Biopsy samples of levator ani muscle were obtained from 22 symptomatic patients with stress urinary incontinence, pelvic organ prolapse, and overlaps (age range 38–74), and nine asymptomatic women (age 31–49). Cryostat sections were investigated for p27 protein expression and type I (slow twitch) and type II (fast twitch) fibers. RESULTS: All fibers exhibited strong plasma membrane (and nuclear) p27 protein expression. cytoplasmic p27 expression was virtually absent in asymptomatic women. In perimenopausal symptomatic patients (ages 38–55), muscle fibers showed hypertrophy and moderate cytoplasmic p27 staining accompanied by diminution of type II fibers. Older symptomatic patients (ages 57–74) showed cytoplasmic p27 overexpression accompanied by shrinking, cytoplasmic vacuolization and fragmentation of muscle cells. The plasma membrane and cytoplasmic p27 expression was not unique to the muscle cells. Under certain circumstances, it was also detected in other cell types (epithelium of ectocervix and luteal cells). CONCLUSIONS: This is the first report on the unusual (plasma membrane and cytoplasmic) expression of p27 protein in normal and abnormal human striated muscle cells in vivo. Our data indicate that pelvic floor disorders are in perimenopausal patients associated with an appearance of moderate cytoplasmic p27 expression, accompanying hypertrophy and transition of type II into type I fibers. The patients in advanced postmenopause show shrinking and fragmentation of muscle fibers associated with strong cytoplasmic p27 expression
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