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This paper quantifies the registration and fusion display errors of augmented reality-based nasal endoscopic surgery (ARNES). We comparatively investigated the spatial calibration process for front-end endoscopy and redefined the accuracy level of a calibrated endoscope by using a calibration tool with improved structural reliability. We also studied how registration accuracy was combined with the number and distribution of the deployed fiducial points (FPs) for positioning and the measured registration time. A physically integrated ARNES prototype was customarily configured for performance evaluation in skull base tumor resection surgery with an innovative approach of dynamic endoscopic vision expansion. As advised by surgical experts in otolaryngology, we proposed a hierarchical rendering scheme to properly adapt the fused images with the required visual sensation. By constraining the rendered sight in a known depth and radius, the visual focus of the surgeon can be induced only on the anticipated critical anatomies and vessel structures to avoid misguidance. Furthermore, error analysis was conducted to examine the feasibility of hybrid optical tracking based on point cloud, which was proposed in our previous work as an in-surgery registration solution. Measured results indicated that the error of target registration for ARNES can be reduced to 0.77 ± 0.07 mm. For initial registration, our results suggest that a trade-off for a new minimal time of registration can be reached when the distribution of five FPs is considered. For in-surgery registration, our findings reveal that the intrinsic registration error is a major cause of performance loss. Rigid model and cadaver experiments confirmed that the scenic integration and display fluency of ARNES are smooth, as demonstrated by three clinical trials that surpassed practicality.

This paper addresses the problem of an event-triggered non-parallel distribution compensation (PDC) control for networked Takagi–Sugeno (T–S) fuzzy systems, under consideration of the limited data transmission bandwidth and the imperfect premise matching membership functions. First, a unified event-triggered T–S fuzzy model is provided, in which: 1) a fuzzy observer with the imperfect premise matching is constructed to estimate the unmeasurable states of the studied system; 2) a fuzzy controller is designed following the same premise as the observer; and 3) an output-based event-triggering transmission scheme is designed to economize the restricted network resources. Different from the traditional PDC method, the synchronous premise between the fuzzy observer and the T–S fuzzy system are no longer needed in this paper. Second, by use of Lyapunov theory, a stability criterion and a stabilization condition are obtained for ensuring asymptotically stable of the studied system. On account of the imperfect premise matching conditions are well considered in the derivation of the above criteria, less conservation can be expected to enhance the design flexibility. Compared with some existing emulation-based methods, the controller gains are no longer required to be known a priori . Finally, the availability of proposed non-PDC design scheme is illustrated by the backing-up control of a truck-trailer system.

Background Plantar pressure measurement has become increasingly useful in the evaluation of plantar health conditions thanks to the recent progression in sensing technology. Due to the large volume and high energy consumption of monitoring devices, traditional systems for plantar pressure measurement are only focused on static or short-term dynamic monitoring. It makes them inappropriate for early detections of plantar symptoms usually presented in long-term activities. Methods A prototype of monitoring system based on body sensor network (BSN) is proposed for quantitative assessment of plantar conditions. To further assess the severity of plantar symptoms which can be reflected from the pressure distribution in motion status, an approach to conjoint analysis of pressure distribution and exercise load quantification based on the strike frequency (SF) and heart rate (HR) is also proposed. Results An examination was tested on 30 subjects to verify the capabilities of the proposed system. The estimated correlation rate with reference devices (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$r>0.9$$\end{document}r>0.9) and error rate on the average (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$R_{AE}

This study focuses on networked H ∞ fuzzy filtering for Markovian jump Takagi-Sugeno (T-S) fuzzy systems. Since the traditional PDC method is ineffective under network environments, a flexible filter design method is provided with imperfect premise matching. First, a unified T-S fuzzy error model is provided by considering the mismatched grades of membership. Second, by use of the constructed model and the Markovian switched Lyapunov-Krasovskii functional, a stability and a stabilisation criteria of the fuzzy filtering error system are derived, in which it is no required that the fuzzy filter shares the same membership functions with the fuzzy systems. Therefore, the designed filter is available under network environments since the mismatched premises induced by networks are well considered. Finally, the effectiveness of the proposed new design method is illustrated by two examples.

A general diagram is proposed to deal with unmatch premises of T-S fuzzy systems under network environments.A less conservative stability criterion is obtained by use of the Wirtinger-based inequality technique to deal with the cross items in the derivation of the main results.A novel imperfect premise matching design method is utilized to enhance the design flexibility for the T-S fuzzy systems under network environments. This paper focuses on an imperfect premise matching controller design for T-S fuzzy systems under network environments. Different with the traditional parallel distribution compensation (PDC) method, the same premises between the PDC controller and the T-S fuzzy systems are no longer needed again in the proposed method. Under consideration of the unmatched grades of membership in the networked T-S fuzzy systems, a unified T-S fuzzy model is firstly proposed, in which a networked state-feedback fuzzy controller with communication delays is used to reconstruct the system. Then, based on the constructed model and by use of the Wirtinger-based inequality technique to deal with the cross items, two less conservative stability and stabilization criteria are derived to enhance the design flexibility. Finally, two numerical examples are used to show the effectiveness of proposed method.

Endoscopic imaging is a common clinical modality to inspect surficial abnormality grew on the internal organs inside human body. Covered by tissue fluid, surface of these anatomies tend to be glossy, showing specular reflections from the illumination source. In this paper, we present a novel method for specular region separation and restoration from only a single image. Distinguishing from segmentation methods using simple threshold, our solution treats the separation of highlight pixels as a binarization problem based upon a supervised learning classification algorithm. Also, we propose a multiscale dynamic image expansion and fusion based method to restore the highlighted region. It takes full advantages of propagating the regions with similar structure features to specular regions. Experimental results on the removal of the endoscopic image with specular reflections demonstrate improved efficiency by the proposed method compared to commonly used techniques.

A graph-based groupwise shape registration algorithm for building statistical shape model (SSM) is proposed, which has been successfully applied to shape prediction of foot scans. Establishing unbiased and effective shape correspondences of large-scale data sets is extremely challenging, for the inappropriate selection of initial mean shape and non-rigid registration of shape with large-scale deformation. To address these issues, first, we use a simplified graph to model the shape distribution in metric space and an edge-guided graph shrinkage to deform the shapes. Then, the groupwise registration is performed by iteratively performing the graph shrinkage until the shape converges. And, the correspondences of training shapes are obtained by propagating the converged shape to the original data along each shrinkage path. Compared with traditional forward and backward models of groupwise registration, the proposed method is data-driven without initial mean shape as input. Moreover, under the constraint of the established graph, the non-rigid registration can perform more accurately by restricting shape register to its neighbors. Based on the shape correspondence, the SSM of foot shapes is constructed and applied to shape prediction by taking the collected anthropometric information as predictor. Experiments demonstrate that the proposed method can obtain robust shape correspondences and SSM capability with respect to model generalization, specificity, and compactness. The application of shape prediction model shows an average prediction error lower than 1% for general foot size. Graphical abstract The graphical abstract of unbiased groupwise registration for foot prediction.

The heart sound signal is a reflection of heart and vascular system motion. Long-term continuous electrocardiogram (ECG) contains important information which can be helpful to prevent heart failure. A single piece of a long-term ECG recording usually consists of more than one hundred thousand data points in length, making it difficult to derive hidden features that may be reflected through dynamic ECG monitoring, which is also very time-consuming to analyze. In this paper, a Dynamic Time Warping based on MapReduce (MRDTW) is proposed to make prognoses of possible lesions in patients. Through comparison of a real-time ECG of a patient with the reference sets of normal and problematic cardiac waveforms, the experimental results reveal that our approach not only retains high accuracy, but also greatly improves the efficiency of the similarity measure in dynamic ECG series.

BACKGROUND The widespread access to portable medical devices or new personal devices is boosting the amount of biomedical data. These devices provide a growing massive data that far exceeds the analytical ability of a professional doctor. The computer-assisted analysis of biomedical data has become an essential tool in medicine diagnosis. OBJECTIVE Due to the advantages of discrete, noise elimination and dimensionality reduction, symbolic representation of biomedical data has attracted great interest. The symbolization results provide efficiently performing at data mining, such as pattern discovery, anomaly detection and association rules mining, so we want to use the method to improving the biomedical data classification. METHODS In this paper, we introduce a novel symbolic representation method, called Trend Feature Symbolic Approximation (TFSA). RESULTS The TFSA focuses on retaining most of the original series’ trend features, and it also very suitable for subsequent mining work, such as association rules mining. CONCLUSION The TFSA provides the lower bounding guarantee and the experimental results show that comparing with some existing methods, its classification accuracy is improved.

The similarity search is one of the fundamental components in time series data mining, e.g. clustering, classification, association rules mining. Many methods have been proposed to measure the similarity between time series, including Euclidean distance, Manhattan distance, and dynamic time warping (DTW). In contrast, DTW has been suggested to allow more robust similarity measure and be able to find the optimal alignment in time series. However, due to its quadratic time and space complexity, DTW is not suitable for large time series datasets. Many improving algorithms have been proposed for DTW search in large databases, such as approximate search or exact indexed search. Unlike the previous modified algorithm, this paper presents a novel parallel scheme for fast similarity search based on DTW, which is called MRDTW (MapRedcue-based DTW). The experimental results show that our approach not only retained the original accuracy as DTW, but also greatly improved the efficiency of similarity measure in large time series.

In this paper, a III–V/silicon hybrid single-mode on-chip laser is presented. The mode-selection mechanism of the hybrid mode laser is based on a racetrack resonator with periodic microstructures. The laser only needs standard photolithography in the whole fabrication process. Better mode characteristics can be realized comparing to simple runway ring laser. Output power of 0.3 mW and the side-mode suppression ratio of larger than 20 dB in continuous-wave are obtained from experiments.

Focal cortical dysplasia (FCD) is the main cause of epilepsy and can be automatically detected via magnetic resonance (MR) images. However, visual detection of lesions is time consuming and highly dependent on the doctor's personal knowledge and experience. In this paper, we propose a new framework for positive unanimous voting (PUV) to detect FCD lesions. Maps of gray matter thickness, gradient, relative intensity, and gray/white matter width are computed in the proposed framework to enhance the differences between lesional and non-lesional regions. Feature maps are further compared with the feature distributions of healthy controls to obtain feature difference maps. PUV driven by feature and feature difference maps is then applied to classify image voxels into lesion and non-lesion. The connected region analysis then refines the classification results by removing the tiny fragment regions consisting of falsely classified positive voxels. The proposed method correctly identified 8/10 patients with FCD lesions and 30/31 healthy people. Experimental results on the small FCD samples demonstrated that the proposed method can effectively reduce the number of false positives and guarantee correct detection of lesion regions compared with four single classifiers and two recent methods.

This paper introduces a discrete Wirtinger-based inequality to investigate the problem of delay-dependent stability analysis of networked control systems. Firstly, a discrete-time system with an interval time-varying delay is used to describe networked control systems with quality-of-service constraints. Then, by constructing a novel augmented Lyapunov-Krasovskii functional and applying the discrete Wirtinger-based inequality and reciprocally convex approach to deal with the sum items in the derivation of the results, two delay-dependent stability criteria are obtained in terms of linear matrix inequalities (LMIs). Numerical examples are provided to show that the derived stability criteria can provide a larger allowable upper delay bound than some existing results while depending on less scalar decision variables.

Disability income insurance (DI) and its pricing in mainland China is discussed with a focus on the current situation, market prospects, and the pricing process. Our study concludes that (1) there is a bright future for commercial DI, but current consumers are mainly urban residents with above-average incomes; (2) by combining health service data and experiences of the insured, one can calculate the premium rate by sex, region, and occupation; and (3) the price of DI should be higher in rural areas than in cities; the commercial DI premium rate is overpriced for people under 45, and underpriced for people over 45.

Objective This paper proposes an unobtrusive blood pressure (BP) measurement system design with a motion artifact (MA) compensation strategy as a potential surrogate to the traditional cuff-based sphygmomanometer for self-monitoring in a less restricted environment. Approach A dual-channel photoplethysmographic signal acquisition system is designed and implemented for cuff-less BP measurement based on the peripheral pulse transit time (PPTT) acquired from the forearm and wrist. Comprising a motion decision, singular spectrum analysis, PPTT calculation and BP measurement, a novel approach is proposed to realize BP measurements and suppress MA interference. Main results Compared with the reference BP recorded by a cuff-based sphygmomanometer, our preliminary examinations on 30 subjects found that the correlation coefficients for systolic BP estimation and diastolic BP estimation were 0.75 and 0.78, and the mean absolute differences were 7.61 mmHg and 6.82 mmHg, respectively. Meanwhile, the proposed approach was compared with the other most widely used pulse transit time (PTT) measuring methods and BP-PTT models. All the results indicate that our work was highly effective in realizing the BP measurement. Significance The proposed system and approach have resulted in remarkable progress in cuff-less BP measurements with MA removal, and have great potential value in wearable applications without environmental restrictions.

Focal cortical dysplasia (FCD) is one of the main causes of epilepsy, and it is of great assistance if the FCD lesions can be localized before the magnetic resonance (MR) imaging guided resective surgery. However, visual detection of these features within the FCD lesional regions is time consuming. - Many automated FCD detection methods have been developed by feature computation, and single classifier based classification. However, the quantity of falsely recognized nonFCD regions as positives is too large that the classification results can be less useful in automated recognition of the FCD lesions. Based on the existing studies, we propose an unanimous voting of the multiple classifiers (UVMC) method to reduce the false positive classification results of the FCD lesions detection. The proposed UVMC method was experimented on 10 MR images of patients with FCD lesions, and 31 MR images of healthy controls. The proposed UVMC method achieved much less number of false positive voxels with improved trade-off between the precision and recall.

The 3rd International Conference on Biomedical Engineering and Biotechnology (iCBEB 2014), held in Beijing from the 25th to the 28th of September 2014, is an annual conference that intends to provide an opportunity for researchers and practitioners around the world to present the most recent advances and future challenges in the fields of biomedical engineering, biomaterials, bioinformatics and computational biology, biomedical imaging and signal processing, biomechanical engineering and biotechnology, amongst others. The papers published in this issue are selected from this conference, which witnesses the advances in biomedical engineering and biotechnology during 2013-2014.

High-brightness, edge-emitting diode laser arrays integrated with a phase shifter have been designed and fabricated at a wavelength of about 910 nm. Stable out-of-phase mode is generated through coupling evanescently and converted to be nearly in-phase by the phase modulation from the phase shifter. With a very simple manufacture process, stable single-lobe far-field pattern is achieved in the slow axis when the continuous wave output power exceeds 460 mW/facet, and the divergence angle is only 2.7 times the diffraction-limited value. Such device shows a promising future for high-brightness application with low cost and easy fabrication.

A non-linear control method, known as Variable Structure Control (VSC), is employed to reduce the duration of ultrasonic (US) transducer transients. A physically realizable system using a simplified form of the VSC algorithm is proposed for standard piezoelectric transducers and simulated. Results indicate a VSC-controlled transmitter reduces the transient duration to less than a carrier wave cycle. Applications include high capacity ultrasound communication and localization systems.

High-brightness 910 nm wavelength edge-emitting laser arrays integrated with a phase-shifter have been designed. Over 450 mW/facet with M2 < 3 is achieved experimentally. Such devices show bright future for low cost and easy fabrication.

In this Letter, a III-V/silicon hybrid single-mode laser operating at C band for photonic integration circuit is presented. The InGaAlAs gain structure is bonded onto a patterned silicon-on insulator through wafer to wafer directly. The mode selected mechanism based on a hybrid III-V/silicon straight cavity with periodic microstructures is applied, which only need low cost i-line projection photolithography in the whole technological process. At room temperature, we obtain 0.62 mW output power in continuous-wave. The side mode suppression ratio of larger than 20 dB is obtained from experiments. [corrected].

In this paper, a III-V/Silicon hybrid single mode laser operating at a long wavelength for photonic integration circuit is presented. The InGaAlAs gain structure is bonded onto a patterned silicon-on insulator wafer directly. The novel mode selected mechanism based on a slotted silicon waveguide is applied, which only need standard photolithography in the whole technological process. The side mode suppression ratio of larger than 20dB is obtained from experiments.