1,769 research outputs found

    An improved chaos method for monitoring the depth of anaesthesia

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    This paper proposed a new method to monitor the depth of anaesthesia (DoA) by modifying the Hurst parameters in Chaos method. Two new indices (CDoA and CsDoA) are proposed to estimate the anaesthesia states of patients. In order to reduce the fluctuation of CDoA and CsDoA trends, the Chaos and Modified Detrended Average methods (C-MDMA) are combined together. Compared with Bispectrum (BIS) index, CDoA, the CsDoA and C-MDMA trends are close to the BIS trend in the whole scale from 100 to 0 with a full recording time

    Chaos-modified detrended moving average methodology for monitoring the depth of anaesthesia

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    This paper proposes a new method to monitor the depth of anaesthesia (DoA) based on the EEG signal. This approach firstly uses discrete wavelet transform (DWT) to to remove the spikes and the low frequency noise from raw EEG signals. After de-noising the EEG signals, the modified Hurst parameter is proposed with two new indices (CDoA and CsDoA), to estimate the anaesthesia states of the patients. To reduce the fluctuation of the new DoA index, a combination of Modified Chaos and Modifying Detrended Moving Average is used (MC-DMA). Analyses of variance (ANOVA) for C-MDMA and BIS distributions are presented The results indicate that the C-MDMA distributions at each anaesthesia state level are significantly different and the C-MDMA can distinguish five depths of anaesthesia. Compared with BIS trends, MC-DMA trend is close to BIS trend covering the whole scale from 100 to 0 with a full recording time

    Total knee arthroplasty for primary knee osteoarthritis: Changing pattern over the past 10 years

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    Objective: To review the epidemiology of total knee arthroplasty for primary osteoarthritis and the change of patient characteristics over the last decade. Design: Retrospective review. Setting: A tertiary referral centre for joint replacement surgery in a teaching hospital in Hong Kong. Patients: All patients who underwent primary total knee arthroplasty for primary knee osteoarthritis from January 2000 to December 2009. Results: In all, 1157 total knee arthroplasties (589 left and 568 right) were performed on 588 females and 162 males. The annual number of total knee arthroplasties increased from 91 in 2000 to 181 in 2009. The annual number of patients increased from 58 (46 female, 12 male) in 2000 to 159 (117 female, 42 male) in 2009. When compared yearly results, there were no significant changes in the preoperative Knee Society Knee Score, Knee Society Functional Assessment, and passive range of motion of these patients. However, there was a significant decreasing trend with regard to lower limb mechanical axis mal-alignment, from 15.1° deviation from the neutral axis in 2000, to 14.8° deviation in 2004, and then 12.9° deviation in 2009 (mostly varus deformity). There was no difference between left knees and right knees, and between females and males. The mean age of the patients did not show significant change over the past decade, but the number and proportion of patients over 80 years old showed an increase from 4.8% (2000 to 2004) to 13.8% (2005 to 2009). On the other hand, the number and proportion of patients under the age of 60 years did not change. Conclusions: There was an increasing trend towards total knee arthroplasties, both in terms of number of operations and patients. The number of younger patients having total knee arthroplasty did not increase over the last 10 years, whereas the number of those older than 80 years increased significantly over that period.published_or_final_versio

    Classifying rational densities using two one-dimensional cellular automata

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    Given a (finite but arbitrarily long) string of zeros and ones, we report a way to determine if the number of ones is less than, greater than, or equal to a prescribed number by applying two sets of cellular automation rules in succession. Thus, we solve the general one-dimensional density classification problem using two cellular automata.published_or_final_versio

    Comparison of fatty-acid-binding protein 4 and adiponectin levels in infrapatellar fat pad and subcutaneous adipose tissue, synovial fluid and plasma in subjects with knee osteoarthritis

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    Conference Theme: Defying the Aging Spine: Our Mission ContinuesConcurrent Free Papers 2 - Basic Science/General Orthopaedics: no. 2.8Introduction: It was recently reported that inflammation is involved in the pathogenesis of osteoarthritis (OA). Fattyacid-binding protein 4 (FABP4) and adiponectin are both adipocyte-derived cytokines closely related with inflammation pathways. The FABP4 exhibits a pro-inflammatory property while adiponectin shows anti-inflammatory effect. The study aimed to assess the expression of FABP4 and adiponectin in paired blood and synovial fluid from OA patients, and to examine whether the infrapatellar fat pad (IPFP) from OA subjects would release FABP4 and adiponectin similar to that of donor-matched subcutaneous adipose tissue (ScAT). Materials and Methods: Plasma, synovial fluid, ScAT, and IPFP of 20 OA patients (4 males and 16 females) were collected during total knee arthroplasty. Levels of FABP4 and adiponectin were measured in plasma, synovial fluid, and fat conditioned media using ELISA (AIS, HKU). Results: Levels of FABP4 were significantly higher in IPFP media than ScAT (p = 0.015), while the same were significantly higher in synovial fluid than in plasma (p < 0.001). There were no significant differences of adiponectin levels between IPFP and ScAT media (p = 0.737). Plasma levels of adiponectin were significantly higher than synovial fluid (p < 0.001). Discussion and Conclusion: The OA patients exhibit an inflammatory state in local environment (IPFP and synovial fluid) compared with systemic environment (ScAT and plasma). The IPFP may play a key role in OA inflammation and may be an important resource of inflammatory mediators in synovial fluid.postprin

    Surgical debridement with prostheses retention for the treatment of acute periprosthetic infections following total knee arthroplasty

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    Free Paper Presentation Session 6 – Adult Joint Reconstruction: no. 6.3INTRODUCTION: Periprosthetic infection after total knee arthroplasty (TKA) is difficult to treat. Surgical debridement with retention of prostheses is one of the valid methods ...postprin

    Case series of Jehovah's witnesses having Total Knee Arthroplasty in Hong Kong

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    Electronic Poster Presentations: P48INTRODUCTION: Total knee arthroplasty (TKA) is challenging in Jehovah’s Witnesses (JW), as they do not accept transfusions. We report our experiences with a series of TKAs in JW in our ...postprin

    Computer simulation of SF6 arcs in a duo-flow hybrid circuit breaker

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    Wind-induced vibration analysis of the Hong Kong Ting Kau Bridge

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    Because of their high flexibility and relatively low structural damping, long-span bridges are prone to wind-induced vibration. An efficient wind field simulation technique for wind-induced vibration analysis of long-span bridges is first introduced in this paper. The time-domain expressions for the buffeting and self-excited forces acting on long-span bridges can then be found from the wind velocities. Based on the above theory and the aerodynamic parameters obtained by wind tunnel tests, a study of the wind fluctuations and aerodynamic forces is carried out on the Hong Kong Ting Kau Bridge, which is a cable-stayed bridge comprising two main spans and two side spans. The buffeting response of the bridge is analysed in the time domain by using step-by-step numerical integration techniques. The aerodynamic behaviour of the bridge can therefore be obtained, and the safety performance of the bridge against strong wind can further be evaluated. Numerical results basically agree with the experimental data, indicating that the theory presented in this paper is applicable to engineering practice.published_or_final_versio
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