14 research outputs found

    Fuzzy rule based multiwavelet ECG signal denoising

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    Since different multiwavelets, pre- and post-filters have different impulse responses and frequency responses, different multiwavelets, pre- and post-filters should be selected and applied at different noise levels for signal denoising if signals are corrupted by additive white Gaussian noises. In this paper, some fuzzy rules are formulated for integrating different multiwavelets, pre- and post-filters together so that expert knowledge on employing different multiwavelets, pre- and post-filters at different noise levels on denoising performances is exploited. When an ECG signal is received, the noise level is first estimated. Then, based on the estimated noise level and our proposed fuzzy rules, different multiwavelets, pre- and post-filters are integrated together. A hard thresholding is applied on the multiwavelet coefficients. According to extensive numerical computer simulations, our proposed fuzzy rule based multiwavelet denoising algorithm outperforms traditional multiwavelet denoising algorithms by 30%

    Autonomous response of a third-order digital filter with two’s complement arithmetic realized in parallel form

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    This paper investigates the output and state trajectories of a third-order digital filter with two’s complement arithmetic realized in parallel form. Although the output of the third-order digital filter seems to behave randomly, some regular patterns can be displayed on the plot of versus , where those regular patterns are similar to the second-order case. When the first-order subsystem is operated at the marginally stable points, the output of the third-order system is still mainly dependent on the behaviors of the corresponding second-order digital filter, even though overflow occurs. Explicit equations relating the trajectories of the system to the filter parameters and the initial conditions provide further insights into the behaviors of the system

    Fuzzy multiwavelet denoising on an ECG signal

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    Since different multiwavelets, pre- and post-filters have different impulse and frequency responses characteristics, different multiwavelets, pre- and post-filters should be selected, integrated and applied at different noise levels if a signal is corrupted by an additive white Gaussian noise (AWGN). In this letter, some fuzzy rules on selecting and integrating different multiwavelets, pre- and post-filters together are proposed. These fuzzy rules are setup based on the training results of the denoising performances of applying different multiwavelets, pre- and post-filters at different noise levels. When a new electrocardiogram (ECG) signal is applied, the appropriate multiwavelets, pre- and post-filters are selected and integrated based on fuzzy rules and the noise level of the signal. A hard thresholding is applied on the multiwavelet coefficients. According to an extensive simulation, we found that our proposed fuzzy rule-based multiwavelet denoising algorithm achieves 30% improvement compared to the traditional multiwavelet denoising algorithms

    Controlled comparison of hemodialysis and peritoneal dialysis: Veterans Administration multicenter study

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    Controlled comparison of hemodialysis and peritoneal dialysis: Veterans Administration multicenter study. We measured mortality and morbidity among 114 patients assigned randomly to home hemodialysis (HD) and home intermittent peritoneal dialysis (IPD). Data were collected during the time of home training and for 12 months after initiation of home dialysis. Training time was shorter for the IPD than for the HD patients (P < 0.001) with median time 1.8 months for IPD and 3.9 months for HD. Switching to the alternative mode of treatment was more frequent for the IPD group (29/59 vs. 5/55, P < 0.001). Survival time was not different, perhaps because of the modality change. More IPD patients were hospitalized in the first 6 months (20 for IPD vs. 9 for HD, P = 0.02), but they had fewer troublesome cardiovascular events in the first year (0 vs. 12, P < 0.001). The HD patients maintained better nutritional status as reflected in body weight and arm muscle circumference and possibly in urea appearance rate. Thus, these data suggest that for most patients, IPD is a less satisfactory form of therapy than HD, but certain advantages of IPD did emerge. Applications of this information to the currently more popular mode of CAPD await further study.Comparaison contrôlée entre l'hémodialyse et la dialyse péritonéale: Étude multicentrique de l'Administration des Veterans. Nous avons mesuré la mortalité et la morbidité chez 114 malades, pris au hasard, en hémodialyse à domicile (HD) ou en dialyse péritonéale intermittente à domicile (IPD). Les données ont été recueillies pendant l'entrainement à domicile et pendant les 12 mois suivant le début de la dialyse à domicile. La durée d'entrainement était plus brève pour les malades en IPD que pour ceux en HD (P < 0,001), avec un temps médian de 1,8 mois pour l'IPD et de 3,9 mois pour l'HD. Le changement pour l'autre mode de traitement était plus fréquent pour le groupe IPD (29/59 contre 5/55, P < 0,001). La durée de suivi n'était pas différente, peut-être à cause du changement de modalité. Plus de malades en IPD ont été hospitalisés dans les 6 premiers mois (20 en IPD, contre 9 en HD, P = 0,02), mais ils ont eu moins d'ennuis cardiovasculaires gênants au cours de la première année (0 contre 12, P < 0,001). Les malades HD conservaient un meilleur état nutritionnel, reflété par le poids corporel, la circonférence musculaire du bras, et probablement la vitesse d'apparition de l'urée. Ainsi ces données suggèrent que pour la plupart des malades, l'IPD est une forme de traitement moins satisfaisante que l'HD, mais certains avantages de l'IPD sont apparus. Les applications de cette information au mode actuellement le plus répandu de CAPD requièrent d'autres études

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    Phacoemulsification Versus Combined Phacotrabeculectomy in Medically Controlled Chronic Angle Closure Glaucoma with Cataract

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    Objective: To compare phacoemulsification alone versus combined phacotrabeculectomy in medically controlled chronic angle closure glaucoma (CACG) with coexisting cataract. Design: Randomized clinical trial. Participants: Seventy-two medically controlled CACG eyes with coexisting cataract. Intervention: Recruited patients were randomized into group 1 (phacoemulsification alone) or group 2 (combined phacotrabeculectomy with adjunctive mitomycin C). Postoperatively, patients were reviewed every 3 months for 2 years. Main Outcome Measures: Intraocular pressure (IOP) and requirement for topical glaucoma drugs. Results: Thirty-five CACG eyes were randomized into group 1, and 37 CACG eyes were randomized into group 2. There were no statistically significant differences (P>0.05) in mean IOP between the 2 treatment groups preoperatively and postoperatively, except at 1 month (P = 0.001) and 3 months (P = 0.008). Combined phacotrabeculectomy with adjunctive mitomycin C resulted in 0.80 less topical glaucoma drugs (P<0.001) in the 24-month postoperative period compared with phacoemulsification alone. The differences in IOP control were, however, not associated with differences in glaucomatous progression. Combined surgery was associated with more postoperative (P<0.001) complications compared with phacoemulsification alone. Conclusions: Combined phacotrabeculectomy with adjunctive mitomycin C may be marginally more effective than phacoemulsification alone in controlling IOP in medically controlled CACG eyes with coexisting cataract. Combined surgery may be associated with more complications and additional surgery in the postoperative period. Further study is needed to determine whether the marginally better IOP control of combined surgery justifies the potential additional risks of complications and further surgery. Financial Disclosure(s): The authors have no proprietary or commercial interest in any materials discussed in this article. © 2008 American Academy of Ophthalmology.link_to_subscribed_fulltex
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