Optimization-based interactive segmentation interface for multiregion problems.

Interactive segmentation is becoming of increasing interest to the medical imaging community in that it combines the positive aspects of both manual and automated segmentation. However, general-purpose tools have been lacking in terms of segmenting multiple regions simultaneously with a high degree of coupling between groups of labels. Hierarchical max-flow segmentation has taken advantage of this coupling for individual applications, but until recently, these algorithms were constrained to a particular hierarchy and could not be considered general-purpose. In a generalized form, the hierarchy for any given segmentation problem is specified in run-time, allowing different hierarchies to be quickly explored. We present an interactive segmentation interface, which uses generalized hierarchical max-flow for optimization-based multiregion segmentation guided by user-defined seeds. Applications in cardiac and neonatal brain segmentation are given as example applications of its generality

EEG signals analysis using multiscale entropy for depth of anesthesia monitoring during surgery through artificial neural networks

In order to build a reliable index to monitor the depth of anesthesia (DOA), many algorithms have been proposed in recent years, one of which is sample entropy (SampEn), a commonly used and important tool to measure the regularity of data series. However, SampEn only estimates the complexity of signals on one time scale. In this study, a new approach is introduced using multiscale entropy (MSE) considering the structure information over different time scales. The entropy values over different time scales calculated through MSE are applied as the input data to train an artificial neural network (ANN) model using bispectral index (BIS) or expert assessment of conscious level (EACL) as the target. To test the performance of the new index's sensitivity to artifacts, we compared the results before and after filtration by multivariate empirical mode decomposition (MEMD). The new approach via ANN is utilized in real EEG signals collected from 26 patients before and after filtering by MEMD, respectively; the results show that is a higher correlation between index from the proposed approach and the gold standard compared with SampEn. Moreover, the proposed approach is more structurally robust to noise and artifacts which indicates that it can be used for monitoring the DOA more accurately.This research was financially supported by the Center for Dynamical Biomarkers and Translational Medicine, National Central University, Taiwan, which is sponsored by Ministry of Science and Technology (Grant no. MOST103-2911-I-008-001). Also, it was supported by National Chung-Shan Institute of Science & Technology in Taiwan (Grant nos. CSIST-095-V301 and CSIST-095-V302) and National Natural Science Foundation of China (Grant no. 51475342)

Investigating properties of the cardiovascular system using innovative analysis algorithms based on ensemble empirical mode decomposition

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited - Copyright @ 2012 Jia-Rong Yeh et al.Cardiovascular system is known to be nonlinear and nonstationary. Traditional linear assessments algorithms of arterial stiffness and systemic resistance of cardiac system accompany the problem of nonstationary or inconvenience in practical applications. In this pilot study, two new assessment methods were developed: the first is ensemble empirical mode decomposition based reflection index (EEMD-RI) while the second is based on the phase shift between ECG and BP on cardiac oscillation. Both methods utilise the EEMD algorithm which is suitable for nonlinear and nonstationary systems. These methods were used to investigate the properties of arterial stiffness and systemic resistance for a pig's cardiovascular system via ECG and blood pressure (BP). This experiment simulated a sequence of continuous changes of blood pressure arising from steady condition to high blood pressure by clamping the artery and an inverse by relaxing the artery. As a hypothesis, the arterial stiffness and systemic resistance should vary with the blood pressure due to clamping and relaxing the artery. The results show statistically significant correlations between BP, EEMD-based RI, and the phase shift between ECG and BP on cardiac oscillation. The two assessments results demonstrate the merits of the EEMD for signal analysis.This work is supported by the National Science Council (NSC) of Taiwan (Grant number NSC 99-2221-E-155-046-MY3), Centre for Dynamical Biomarkers and Translational Medicine, National Central University, Taiwan which is sponsored by National Science Council (Grant number: NSC 100–2911-I-008-001) and the Chung-Shan Institute of Science & Technology in Taiwan (Grant numbers: CSIST-095-V101 and CSIST-095-V102)

Medical Student Mandala Making for Holistic Well-Being

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An analysis of the energy flow and energy potential from human energy harvesting with a focus on walking

This paper aims to determine the limitations for electrical energy generation from harvesting mechanical work during walking. The assessment was considered from the point of chemical energy ingested in food, through the development of mechanical work, to the conversion into useful electrical energy from the perspective of the conversion efficiencies. An average person was considered, with four mechanical to electrical energy conversion technologies assessed. It was found that for an individual walking on level ground a potential of up to 5 J/step of electrical energy is available. Stair use impacts this, where stair ascent decreased and descent increased the potential. It was concluded that, although the energy outputs are small, they scale with the number of people, where an estimated potential of 900 MWh/day is calculated in the UK. Harvesting even a fraction of this available potential would appear worthwhile, however, it is unclear if this potential can be practically utilised

Stabilized conforming nodal integration: Exactness and variational justification

In most Galerkin mesh-free methods, background integration cells partitioning the problem domain are required to evaluate the weak form. It is therefore worthwhile to consider these methods using the notions of domain decomposition with the integration cells being the subdomains. Presuming that the analytical solution is admissible in the trial solution, domain and boundary integration exactness, which depend on the orders of the employed trial solution and the required solution exactness, are identified for the strict satisfaction of traction reciprocity and natural boundary condition in the weak form. Unfortunately, trial solutions constructed by many mesh-free approximants contain non-polynomial terms which cannot be exactly integrated by Gaussian quadratures. Recently, stabilized conforming (SC) nodal integration for Galerkin mesh-free methods was proposed and illustrated to be linearly exact. This paper will discuss how linear exactness is ensured and how spurious oscillation encountered by direct nodal integration is suppressed in SC nodal integration from a domain decomposition point of view. Moreover, it will be shown that SC nodal integration can be formulated by the Hellinger-Reissner Principle and thus justified in the classical variational sense. Applications of the method to straight beam, plate and curved beam problems are presented. © 2004 Elsevier B.V. All rights reserved.postprin

Art-making in a family medicine clerkship: how does it affect medical student empathy?

Background: To provide patient-centred holistic care, doctors must possess good interpersonal and empathic skills. Medical schools traditionally adopt a skills-based approach to such training but creative engagement with the arts has also been effective. A novel arts-based approach may help medical students develop empathic understanding of patients and thus contribute to medical students’ transformative process into compassionate doctors. This study aimed to evaluate the impact of an arts-making workshop on medical student empathy. Methods: This was a mixed-method quantitative-qualitative study. In the 2011-12 academic year, all 161 third year medical students at the University of Hong Kong were randomly allocated into either an arts-making workshop or a problem-solving workshop during the Family Medicine clerkship according to a centrally-set timetable. Students in the arts-making workshop wrote a poem, created artwork and completed a reflective essay while students in the conventional workshop problem-solved clinical cases and wrote a case commentary. All students who agreed to participate in the study completed a measure of empathy for medical students, the Jefferson Scale of Empathy (JSE) (student version), at the start and end of the clerkship. Quantitative data analysis: Paired t-test and repeated measures ANOVA was used to compare the change within and between groups respectively. Qualitative data analysis: Two researchers independently chose representational narratives based on criteria adapted from art therapy. The final 20 works were agreed upon by consensus and thematically analysed using a grounded theory approach. Results: The level of empathy declined in both groups over time, but with no statistically significant differences between groups. For JSE items relating to emotional influence on medical decision making, participants in the arts-making workshop changed more than those in the problem-solving workshop. From the qualitative data, students perceived benefits in arts-making, and gained understanding in relation to self, patients, pain and suffering, and the role of the doctor. Conclusions: Though quantitative findings showed little difference in empathy between groups, arts-making workshop participants gained empathic understanding in four different thematic areas. This workshop also seemed to promote greater self-awareness which may help medical students recognize the potential for emotions to sway judgment. Future art workshops should focus on emotional awareness and regulation.  published_or_final_versio

Flyglow: Single-fly observations of simultaneous molecular and behavioural circadian oscillations in controls and an Alzheimer's model.

Circadian rhythms are essential for health and are frequently disturbed in disease. A full understanding of the causal relationships between behavioural and molecular circadian rhythms requires simultaneous longitudinal observations over time in individual organisms. Current experimental paradigms require the measurement of each rhythm separately across distinct populations of experimental organisms, rendering the comparability of the resulting datasets uncertain. We therefore developed FLYGLOW, an assay using clock gene controlled luciferase expression detected by exquisitely sensitive EM-CCD imaging, to enable simultaneous quantification of parameters including locomotor, sleep consolidation and molecular rhythms in single flies over days/weeks. FLYGLOW combines all the strengths of existing techniques, and also allows powerful multiparametric paired statistics. We found the age-related transition from rhythmicity to arrhythmicity for each parameter occurs unpredictably, with some flies showing loss of one or more rhythms during middle-age. Using single-fly correlation analysis of rhythm robustness and period we demonstrated the independence of the peripheral clock from circadian behaviours in wild type flies as well as in an Alzheimer's model. FLYGLOW is a useful tool for investigating the deterioration of behavioural and molecular rhythms in ageing and neurodegeneration. This approach may be applied more broadly within behavioural neurogenetics research

A surface plasmon enhanced FLIM-FRET imaging approach based on Au nanoparticles

In this report we have demonstrated a fluorescence resonant energy transfer (FRET)-fluorescence lifetime imaging microscopy (FLIM) combined approach to study the intracellular pathway of gold nanoparticles. The detected energy transfer between gold nanorods (GNRs) and green fluorescence protein (GFP) labeled Hela cell earlyendosomes and the in-depth lifetime distribution analysis on the transfer process suggest an endocytotic uptake process of GNRs. Furthermore, the FRET-FLIM method profits from a surface plasmon enhanced energy transfer mechanism when taking into consideration of GNRs and two photon excitation, and is effective in biological imaging, sensing, and even in single molecular tracing in both in vivo and in vitro studies

A 2000 BPS LPC vocoder based on multiband excitation

This paper presents an improved mixed LPC vocoder at 2000 bps using Multi-Band Excitation analysis by a synthesis algorithm. The new vocoder determines the voiced/unvoiced characteristics harmonic by harmonic in a frame, and finds the first voiced/unvoiced transition as the cut-off frequency, which is more accurate and efficient than traditional cut-off frequency detection. The synthetic speech below the cut-off frequency is excited by a series of voiced harmonics, while the signal above the cut-off frequency is simulated by a noise source. The final output speech is the sum of these two outputs. To increase the naturalness and clearness of the synthesized speech, this model applies phase prediction and spectral enhancement in the synthesizer. It is also possible to reduce the bit rate to 1200 bps. Informal listening tests indicate that the output speech possesses higher intelligibility and quality than that of the 2.4 kbps LPC-10e standard, and is comparable with the 4.8 kbps FS1016 CELP vocoder.published_or_final_versio