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Du W.,CAS Shenzhen Institutes of Advanced Technology | Du W.,Shenzhen Key Laboratory for Low cost Healthcare | Li H.,CAS Shenzhen Institutes of Advanced Technology | Li H.,Shenzhen Key Laboratory for Low cost Healthcare | And 4 more authors.
2016 IEEE International Conference on Information and Automation, IEEE ICIA 2016 | Year: 2016

Constant physical work is the leading cause of low back pain (LBP) in nurses, which affects their well-being and working efficiency. With this study, we aimed to explore the features of lumbar muscles including multifidi (MF) and musculus tiansversus abdominis (MTA) of nurses with LBP suffering from lumbar disc herniation (LDH). We estimated the degree of lumbar muscle strain by compaiiug the lumbar muscle thickness between nurses with LDH and healthy subjects. In this experiment participated thirty-one patients with LDH and 37 healthy controls. We asked the subjects to perform five cycles of forward and backward bending from a standing position. Meanwhile, we captured sonomyographic images of multifidi (MF) and musculi trausversus abdominis (MTA). As results, the muscle thickness of MTA from light side showed significant difference between healthy female subjects and female nurses with LDH (p=0.00K0.05 ). LDH subjects exhibited a lower muscle thickness than that of healthy subjects duiing forward bending. Also, the MTA thickness of controls was lower than that of LDH nurses duiing backward bending. We also found that higher age of LDH nurses was associated with higher muscle thickness of the mo explored muscles. Higher scores from the Oswestry Disability Questionnaire scores correspond to a higher thickness of light MF and left MTA and lower thickness of the light MTA, respectively. © 2016 IEEE.

Du L.,Shenzhen Key Laboratory for Low cost Healthcare | Yan Y.,Shenzhen Key Laboratory for Low cost Healthcare | Wu W.,Shenzhen Key Laboratory for Low cost Healthcare | Mei Q.,Guangdong University of Technology | And 3 more authors.
Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS | Year: 2013

Multiple-lead dynamic ECG recorders (Holter) play an important role in the earlier detection of various cardiovascular diseases. In this paper, we present the first several steps towards a 12-lead Holter system with high-performance AFE (Analogue Front-End) and enhanced digital processing. The system incorporates an analogue front-end chip (ADS1298 from TI), which has not yet been widely used in most commercial Holter products. A highly-efficient data management module was designated to handle the data exchange between the ADS1298 and the microprocessor (STM32L151 from ST electronics). Furthermore, the system employs a Field Programmable Gate Array (Spartan-3E from Xilinx) module, on which a dedicated real-time 227-step FIR filter was executed to improve the overall filtering performance, since the ADS1298 has no high-pass filtering capability and only allows limited low-pass filtering. The Spartan-3E FPGA is also capable of offering further on-board computational ability for a smarter Holter. The results indicate that all functional blocks work as intended. In the future, we will conduct clinical trials and compare our system with other state-of-the-arts. © 2013 IEEE.

Liu G.-Z.,Sun Yat Sen University | Wu D.,CAS Shenzhen Institutes of Advanced Technology | Mei Z.-Y.,CAS Shenzhen Institutes of Advanced Technology | Zhu Q.-S.,CAS Shenzhen Institutes of Advanced Technology | And 2 more authors.
Journal of Central South University | Year: 2013

Respiratory monitoring is increasingly used in clinical and healthcare practices to diagnose chronic cardio-pulmonary functional diseases during various routine activities. Wearable medical devices have realized the possibilities of ubiquitous respiratory monitoring, however, relatively little attention is paid to accuracy and reliability. In previous study, a wearable respiration biofeedback system was designed. In this work, three kinds of signals were mixed to extract respiratory rate, i.e., respiration inductive plethysmography (RIP), 3D-acceleration and ECG. In-situ experiments with twelve subjects indicate that the method significantly improves the accuracy and reliability over a dynamic range of respiration rate. It is possible to derive respiration rate from three signals within mean absolute percentage error 4.37% of a reference gold standard. Similarly studies derive respiratory rate from single-lead ECG within mean absolute percentage error 17% of a reference gold standard. © 2013 Central South University Press and Springer-Verlag Berlin Heidelberg.

Yu S.,CAS Shenzhen Institutes of Advanced Technology | Yu S.,Shenzhen Key Laboratory for Low cost Healthcare | Zhang R.,CAS Shenzhen Institutes of Advanced Technology | Zhang R.,Shenzhen Key Laboratory for Low cost Healthcare | And 5 more authors.
BioMedical Engineering Online | Year: 2013

Background: Fetal spinal magnetic resonance imaging (MRI) is a prenatal routine for proper assessment of fetus development, especially when suspected spinal malformations occur while ultrasound fails to provide details. Limited by hardware, fetal spine MR images suffer from its low resolution.High-resolution MR images can directly enhance readability and improve diagnosis accuracy. Image interpolation for higher resolution is required in clinical situations, while many methods fail to preserve edge structures. Edge carries heavy structural messages of objects in visual scenes for doctors to detect suspicions, classify malformations and make correct diagnosis. Effective interpolation with well-preserved edge structures is still challenging.Method: In this paper, we propose an edge-directed interpolation (EDI) method and apply it on a group of fetal spine MR images to evaluate its feasibility and performance. This method takes edge messages from Canny edge detector to guide further pixel modification. First, low-resolution (LR) images of fetal spine are interpolated into high-resolution (HR) images with targeted factor by bi-linear method. Then edge information from LR and HR images is put into a twofold strategy to sharpen or soften edge structures. Finally a HR image with well-preserved edge structures is generated. The HR images obtained from proposed method are validated and compared with that from other four EDI methods. Performances are evaluated from six metrics, and subjective analysis of visual quality is based on regions of interest (ROI).Results: All these five EDI methods are able to generate HR images with enriched details. From quantitative analysis of six metrics, the proposed method outperforms the other four from signal-to-noise ratio (SNR), peak signal-to-noise ratio (PSNR), structure similarity index (SSIM), feature similarity index (FSIM) and mutual information (MI) with seconds-level time consumptions (TC). Visual analysis of ROI shows that the proposed method maintains better consistency in edge structures with the original images.Conclusions: The proposed method classifies edge orientations into four categories and well preserves structures. It generates convincing HR images with fine details and is suitable in real-time situations. Iterative curvature-based interpolation (ICBI) method may result in crisper edges, while the other three methods are sensitive to noise and artifacts. © 2013 Yu et al.; licensee BioMed Central Ltd.

Nie Z.,CAS Shenzhen Institutes of Advanced Technology | Nie Z.,Shenzhen Key Laboratory for Low Cost Healthcare | Ma J.,Testing and Technology Center for Industrial Products | Li Z.,CAS Shenzhen Institutes of Advanced Technology | And 5 more authors.
Sensors (Switzerland) | Year: 2012

This paper presents the first characterization and modeling of dynamic propagation channels for human body communication (HBC). In-situ experiments were performed using customized transceivers in an anechoic chamber. Three HBC propagation channels, i.e., from right leg to left leg, from right hand to left hand and from right hand to left leg, were investigated under thirty-three motion scenarios. Snapshots of data (2,800,000) were acquired from five volunteers. Various path gains caused by different locations and movements were quantified and the statistical distributions were estimated. In general, for a given reference threshold è = -10 dB, the maximum average level crossing rate of the HBC was approximately 1.99 Hz, the maximum average fade time was 59.4 ms, and the percentage of bad channel duration time was less than 4.16%. The HBC exhibited a fade depth of -4 dB at 90% complementary cumulative probability. The statistical parameters were observed to be centered for each propagation channel. Subsequently a Fritchman model was implemented to estimate the burst characteristics of the on-body fading. It was concluded that the HBC is motion-insensitive, which is sufficient for reliable communication link during motions, and therefore it has great potential for body sensor/area networks. © 2012 by the authors; licensee MDPI, Basel, Switzerland.

Wen T.,CAS Shenzhen Institutes of Advanced Technology | Wen T.,University of Chinese Academy of Sciences | Wen T.,Shenzhen Key Laboratory for Low cost Healthcare | Zhu Q.,CAS Shenzhen Institutes of Advanced Technology | And 12 more authors.
Biomedical Signal Processing and Control | Year: 2013

Freehand three-dimensional ultrasound imaging is a highly attractive research area because it is capable of volumetric visualization and analysis of tissues and organs. The reconstruction algorithm plays a key role to the construction of three-dimensional ultrasound volume data with higher image quality and faster reconstruction speed. However, a systematic approach to such problem is still missing. A new fast marching method (FMM) for three-dimensional ultrasound volume reconstruction using the tracked and hand-held probe is proposed in this paper. Our reconstruction approach consists of two stages: bin-filling stage and hole-filling stage. Each pixel in the B-scan images is traversed and its intensity value is assigned to its nearest voxel in the bin-filling stage. For the efficient and accurate reconstruction, we present a new hole-filling algorithm based on the fast marching method. Our algorithm advances the interpolation boundary along its normal direction and fills the area closest to known voxel points in first, which ensure that the structural details of image can be preserved. Experimental results on both ultrasonic abdominal phantom and in vivo urinary bladder of human subject and comparisons with some popular algorithms are used to demonstrate its improvement in both reconstruction accuracy and efficiency. © 2013 The Authors. Published by Elsevier Ltd. All rights reserved.

Wen T.,CAS Shenzhen Institutes of Advanced Technology | Gu J.,CAS Shenzhen Institutes of Advanced Technology | Gu J.,Shenzhen Key Laboratory for Low Cost Healthcare | Li L.,CAS Shenzhen Institutes of Advanced Technology | And 5 more authors.
Ultrasonic Imaging | Year: 2016

Ultrasound is one of the most important medical imaging modalities for its real-time and portable imaging advantages. However, the contrast resolution and important details are degraded by the speckle in ultrasound images. Many speckle filtering methods have been developed, but they are suffered from several limitations, difficult to reach a balance between speckle reduction and edge preservation. In this paper, an adaptation of the nonlocal total variation (NLTV) filter is proposed for speckle reduction in ultrasound images. The speckle is modeled via a signaldependent noise distribution for the log-compressed ultrasound images. Instead of the Euclidian distance, the statistical Pearson distance is introduced in this study for the similarity calculation between image patches via the Bayesian framework. And the Split-Bregman fast algorithm is used to solve the adapted NLTV despeckling functional. Experimental results on synthetic and clinical ultrasound images and comparisons with some classical and recent algorithms are used to demonstrate its improvements in both speckle noise reduction and tissue boundary preservation for ultrasound images. © 2016 The Author(s).

Yang F.,CAS Shenzhen Institutes of Advanced Technology | Yang F.,Shenzhen Key Laboratory for Low cost Healthcare | Yang F.,University of Chinese Academy of Sciences | Qin W.,CAS Shenzhen Institutes of Advanced Technology | And 8 more authors.
BioMedical Engineering Online | Year: 2012

Background: Computer-assisted surgical navigation aims to provide surgeons with anatomical target localization and critical structure observation, where medical image processing methods such as segmentation, registration and visualization play a critical role. Percutaneous renal intervention plays an important role in several minimally-invasive surgeries of kidney, such as Percutaneous Nephrolithotomy (PCNL) and Radio-Frequency Ablation (RFA) of kidney tumors, which refers to a surgical procedure where access to a target inside the kidney by a needle puncture of the skin. Thus, kidney segmentation is a key step in developing any ultrasound-based computer-aided diagnosis systems for percutaneous renal intervention.Methods: In this paper, we proposed a novel framework for kidney segmentation of ultrasound (US) images combined with nonlocal total variation (NLTV) image denoising, distance regularized level set evolution (DRLSE) and shape prior. Firstly, a denoised US image was obtained by NLTV image denoising. Secondly, DRLSE was applied in the kidney segmentation to get binary image. In this case, black and white region represented the kidney and the background respectively. The last stage is that the shape prior was applied to get a shape with the smooth boundary from the kidney shape space, which was used to optimize the segmentation result of the second step. The alignment model was used occasionally to enlarge the shape space in order to increase segmentation accuracy. Experimental results on both synthetic images and US data are given to demonstrate the effectiveness and accuracy of the proposed algorithm.Results: We applied our segmentation framework on synthetic and real US images to demonstrate the better segmentation results of our method. From the qualitative results, the experiment results show that the segmentation results are much closer to the manual segmentations. The sensitivity (SN), specificity (SP) and positive predictive value (PPV) of our segmentation result can reach 95%, 96% and 91% respectively; As well as we compared our results with the edge-based level set and level set with shape prior method by means of the same quantitative index, such as SN, SP, PPV, which have corresponding values of 97%, 88%, 78% and 81%, 91%, 80% respectively.Conclusions: We have found NLTV denosing method is a good initial process for the ultrasound segmentation. This initial process can make us use simple segmentation method to get satisfied results. Furthermore, we can get the final segmentation results with smooth boundary by using the shape prior after the segmentation process. Every step enjoy simple energy model and every step in this framework is needed to keep a good robust and convergence property. © 2012 Yang et al; licensee BioMed Central Ltd.

Wu S.,CAS Shenzhen Institutes of Advanced Technology | Wu S.,Shenzhen Key Laboratory for Low Cost Healthcare | Yu S.,CAS Shenzhen Institutes of Advanced Technology | Yu S.,Shenzhen Key Laboratory for Low Cost Healthcare | And 4 more authors.
Computational and Mathematical Methods in Medicine | Year: 2013

A new algorithm for feature and contrast enhancement of mammographic images is proposed in this paper. The approach bases on multiscale transform and mathematical morphology. First of all, the Laplacian Gaussian pyramid operator is applied to transform the mammography into different scale subband images. In addition, the detail or high frequency subimages are equalized by contrast limited adaptive histogram equalization (CLAHE) and low-pass subimages are processed by mathematical morphology. Finally, the enhanced image of feature and contrast is reconstructed from the Laplacian Gaussian pyramid coefficients modified at one or more levels by contrast limited adaptive histogram equalization and mathematical morphology, respectively. The enhanced image is processed by global nonlinear operator. The experimental results show that the presented algorithm is effective for feature and contrast enhancement of mammogram. The performance evaluation of the proposed algorithm is measured by contrast evaluation criterion for image, signal-noise-ratio (SNR), and contrast improvement index (CII). © 2013 Shibin Wu et al.

Li H.,CAS Shenzhen Institutes of Advanced Technology | Li H.,Shenzhen Key Laboratory for Low cost Healthcare | Zhao G.,CAS Shenzhen Institutes of Advanced Technology | Zhao G.,Shenzhen Key Laboratory for Low cost Healthcare | And 6 more authors.
BioMedical Engineering Online | Year: 2014

Background: Improvement in muscle strength is an important aim for the rehabilitation of hemiplegia patients. Presently, the rehabilitation prescription depends on the evaluation results of muscle strength, which are routinely estimated by experienced physicians and therefore not finely quantitative. Widely-used quantification methods for disability, such as Barthel Index (BI) and motor component of Functional Independent Measure (M-FIM), yet have limitations in their application, since both of them differentiated disability better in lower than higher disability, and they are subjective and recorded in wide scales. In this paper, to explore finely quantitative measures for evaluation of muscle strength level (MSL), we start with the study on quantified electromyography (EMG) and sonomyography (SMG) features of tibialis anterior (TA) muscles among hemiplegia patients. Methods: 12 hemiplegia subjects volunteered to perform several sets of plantar-flexion movements in the study, and their EMG signals and SMG signals were recorded on TA independently to avoid interference. EMG data were filtered and then the root-mean-square (RMS) was computed. SMG signals, specifically speaking, the muscle thickness of TA, were manually measured by two experienced operators using ultrasonography. Reproducibility of the SMG assessment on TA between operators was evaluated by non-parametric test (independent sample T test). Possible relationship between muscle thickness changes (TC) of TA and muscle strength level of hemiplegia patients was estimated. Results: Mean of EMG RMS between subjects is found linearly correlated with MSL (R2 = 0.903). And mean of TA muscle TC amplitudes is also linearly correlated with MSL among dysfunctional legs (R2 = 0.949). Moreover, rectified TC amplitudes (dysfunctional leg/ healthy leg, DLHL) and rectified EMG signals (DLHL) are found in linear correlation with MSL, with R2 = 0.756 and R2 = 0.676 respectively. Meanwhile, the preliminary results demonstrate that patients' peak values of TC are generally proportional to their personal EMG peak values in 12 dysfunctional legs and 12 healthy legs (R2 = 0.521).Conclusions: It's concluded that SMG could be a promising option to quantitatively estimate MSL for hemiplegia patients during rehabilitation besides EMG. However, after this exploratory study, they should be further investigated on a larger number of subjects. © 2014 Li et al.; licensee BioMed Central Ltd.

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