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Biomedical Engineering, IEEE Transactions on

Issue 6 • Date June 2013

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  • [Front cover]

    Publication Year: 2013 , Page(s): C1
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  • IEEE Transactions on Biomedical Engineering publication information

    Publication Year: 2013 , Page(s): C2
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  • Table of contents

    Publication Year: 2013 , Page(s): 1465 - 1466
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  • Surgical Tool Alignment Guidance by Drawing Two Cross-Sectional Laser-Beam Planes

    Publication Year: 2013 , Page(s): 1467 - 1476
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1359 KB) |  | HTML iconHTML  

    Conventional surgical navigation requires for surgeons to move their sight and conscious off the surgical field when checking surgical tool's positions shown on the display panel. Since that takes high risks of surgical exposure possibilities to the patient's body, we propose a novel method for guiding surgical tool position and orientation directly in the surgical field by a laser beam. In our navigation procedure, two cross-sectional planar laser beams are emitted from the two laser devices attached onto both sides of an optical localizer, and show surgical tool's entry position on the patient's body surface and its orientation on the side face of the surgical tool. In the experiments, our method gave the surgeons precise and accurate surgical tool adjusting and showed the feasibility to apply to both of open and percutaneous surgeries. View full abstract»

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  • A Ridge Ensemble Empirical Mode Decomposition Approach to Clutter Rejection for Ultrasound Color Flow Imaging

    Publication Year: 2013 , Page(s): 1477 - 1487
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1069 KB) |  | HTML iconHTML  

    In color flow imaging, it is a challenging work to accurately extract blood flow information from ultrasound Doppler echoes dominated by the strong clutter components. In this paper, we provide an in-depth analysis of ridge ensemble empirical mode decomposition (R-EEMD) and compare it with the conventional empirical mode decomposition (EMD) framework. R-EEMD facilitates nonuniform and trial-dependent weights obtained by an optimization procedure during ensemble combination and results in less decomposition errors when compared with the conventional ensemble empirical mode decomposition techniques. A theoretic result is then extended to demonstrate that R-EEMD has an ability to solve the mode mixing problem frequently encountered in EMD and improve the decomposition performance with adequate noise strength when separating a composite two-tone signal. Based on the proposed R-EEMD framework, a novel clutter rejection filter for ultrasound color flow imaging is designed. In a series of simulations, the R-EEMD-based filter achieves a significant improvement on blood flow velocity estimation over the state-of-the-art regression filters and decomposition-based filters, such as eigen-based and EMD filters. An experiment on human carotid artery data also verifies that the R-EEMD algorithm achieves minimum clutter energy and maximum blood-to-clutter energy ratio among all the tested techniques. View full abstract»

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  • Consciousness and Depth of Anesthesia Assessment Based on Bayesian Analysis of EEG Signals

    Publication Year: 2013 , Page(s): 1488 - 1498
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1703 KB) |  | HTML iconHTML  

    This study applies Bayesian techniques to analyze EEG signals for the assessment of the consciousness and depth of anesthesia (DoA). This method takes the limiting large-sample normal distribution as posterior inferences to implement the Bayesian paradigm. The maximum a posterior (MAP) is applied to denoise the wavelet coefficients based on a shrinkage function. When the anesthesia states change from awake to light, moderate, and deep anesthesia, the MAP values increase gradually. Based on these changes, a new function BDoA is designed to assess the DoA. The new proposed method is evaluated using anesthetized EEG recordings and BIS data from 25 patients. The Bland-Alman plot is used to verify the agreement of BDoA and the popular BIS index. A correlation between BDoA and BIS was measured using prediction probability PK. In order to estimate the accuracy of DoA, the effect of sample n and variance τ on the maximum posterior probability is studied. The results show that the new index accurately estimates the patient's hypnotic states. Compared with the BIS index in some cases, the BDoA index can estimate the patient's hypnotic state in the case of poor signal quality. View full abstract»

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  • A Comprehensive 3-D Framework for Automatic Quantification of Late Gadolinium Enhanced Cardiac Magnetic Resonance Images

    Publication Year: 2013 , Page(s): 1499 - 1508
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4251 KB) |  | HTML iconHTML  

    Late gadolinium enhanced (LGE) cardiac magnetic resonance (CMR) can directly visualize nonviable myocardium with hyperenhanced intensities with respect to normal myocardium. For heart attack patients, it is crucial to facilitate the decision of appropriate therapy by analyzing and quantifying their LGE CMR images. To achieve accurate quantification, LGE CMR images need to be processed in two steps: segmentation of the myocardium followed by classification of infarcts within the segmented myocardium. However, automatic segmentation is difficult usually due to the intensity heterogeneity of the myocardium and intensity similarity between the infarcts and blood pool. Besides, the slices of an LGE CMR dataset often suffer from spatial and intensity distortions, causing further difficulties in segmentation and classification. In this paper, we present a comprehensive 3-D framework for automatic quantification of LGE CMR images. In this framework, myocardium is segmented with a novel method that deforms coupled endocardial and epicardial meshes and combines information in both short- and long-axis slices, while infarcts are classified with a graph-cut algorithm incorporating intensity and spatial information. Moreover, both spatial and intensity distortions are effectively corrected with specially designed countermeasures. Experiments with 20 sets of real patient data show visually good segmentation and classification results that are quantitatively in strong agreement with those manually obtained by experts. View full abstract»

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  • An Impulse Radio Ultrawideband System for Contactless Noninvasive Respiratory Monitoring

    Publication Year: 2013 , Page(s): 1509 - 1517
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1244 KB) |  | HTML iconHTML  

    We design a impulse radio ultrawideband radar monitoring system to track the chest wall movement of a human subject during respiration. Multiple sensors are placed at different locations to ensure that the backscattered signal could be detected by at least one sensor no matter which direction the human subject faces. We design a hidden Markov model to infer the subject facing direction and his or her chest movement. We compare the performance of our proposed scheme on 15 human volunteers with the medical gold standard using respiratory inductive plethysmography (RIP) belts, and show that on average, our estimation is over 81% correlated with the measurements of a RIP belt system. Furthermore, in order to automatically differentiate between periods of normal and abnormal breathing patterns, we develop a change point detection algorithm based on perfect simulation techniques to detect changes in the subject's breathing. The feasibility of our proposed system is verified by both the simulation and experiment results. View full abstract»

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  • Flocking Multiple Microparticles With Automatically Controlled Optical Tweezers: Solutions and Experiments

    Publication Year: 2013 , Page(s): 1518 - 1527
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (718 KB) |  | HTML iconHTML  

    This paper presents an efficient approach to achieve microparticles flocking with robotics and optical tweezers technologies. All particles trapped by optical tweezers can be automatically moved toward a predefined region without collision. The main contribution of this paper lies in the proposal of several solutions to the flocking manipulation of microparticles in microenvironments. First, a simple flocking controller is proposed to generate the desired positions and velocities for particles' movement. Second, a velocity saturation method is implemented to prevent the desired velocities from exceeding a safe limit. Third, a two-layer control architecture is proposed for the motion control of optical tweezers. This architecture can help make many robotic manipulations achievable under microenvironments. The proposed approach with these solutions can be applied to many bioapplications especially in cell engineering and biomedicine. Experiments on yeast cells with a robot-tweezers system are finally performed to verify the effectiveness of the proposed approach. View full abstract»

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  • Debye Parameter Extraction for Characterizing Interaction of Terahertz Radiation With Human Skin Tissue

    Publication Year: 2013 , Page(s): 1528 - 1537
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (982 KB) |  | HTML iconHTML  

    This paper is concerned with parameter extraction for the double Debye model, which is used for analytically determining human skin permittivity. These parameters are thought to be the origin of contrast in terahertz (THz) images of skin cancer. The existing extraction methods could generate Debye models, which track their measurements accurately at frequencies higher than 1 THz but poorly at lower frequencies, where the majority of permittivity contrast between healthy and diseased skin tissues is actually observed. We propose a global optimization-based parameter extraction, which results in globally accurate tracking and thus supports the full validity of the Debye model for simulating human skin permittivity in the whole usable THz frequencies. Numerical results confirm viability of our novel methodology. View full abstract»

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  • Mechatronic Design of a Fully Integrated Camera for Mini-Invasive Surgery

    Publication Year: 2013 , Page(s): 1538 - 1545
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (762 KB) |  | HTML iconHTML  

    This paper describes the design features of an innovative fully integrated camera candidate for mini-invasive abdominal surgery with single port or transluminal access. The apparatus includes a CMOS imaging sensor, a light-emitting diode (LED)-based unit for scene illumination, a photodiode for luminance detection, an optical system designed according to the mechanical compensation paradigm, an actuation unit for enabling autofocus and optical zoom, and a control logics based on microcontroller. The bulk of the apparatus is characterized by a tubular shape with a diameter of 10 mm and a length of 35 mm. The optical system, composed of four lens groups, of which two are mobile, has a total length of 13.46 mm and an effective focal length ranging from 1.61 to 4.44 mm with a zoom factor of 2.75×, with a corresponding angular field of view ranging from 16° to 40°. The mechatronics unit, devoted to move the zoom and the focus lens groups, is implemented adopting miniature piezoelectric motors. The control logics implements a closed-loop mechanism, between the LEDs and photodiode, to attain automatic control light. Bottlenecks of the design and some potential issues of the realization are discussed. A potential clinical scenario is introduced. View full abstract»

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  • Fold-Preserving Electronic Cleansing Using a Reconstruction Model Integrating Material Fractions and Structural Responses

    Publication Year: 2013 , Page(s): 1546 - 1555
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1051 KB) |  | HTML iconHTML  

    In this paper, we propose an electronic cleansing method using a novel reconstruction model for removing tagged materials (TMs) in computed tomography (CT) images. To address the partial volume (PV) and pseudoenhancement (PEH) effects concurrently, material fractions and structural responses are integrated into a single reconstruction model. In our approach, colonic components including air, TM, an interface layer between air and TM, and an interface layer between soft-tissue (ST) and TM (ILST/TM ) are first segmented. For each voxel in ILST/TM, the material fractions of ST and TM are derived using a two-material transition model, and the structural response to identify the folds submerged in the TM is calculated by the rut-enhancement function based on the eigenvalue signatures of the Hessian matrix. Then, the CT density value of each voxel in ILST/TM is reconstructed based on both the material fractions and structural responses. The material fractions remove the aliasing artifacts caused by a PV effect in ILST/TM effectively while the structural responses avoid the erroneous cleansing of the submerged folds caused by the PEH effect. Experimental results using ten clinical datasets demonstrated that the proposed method showed higher cleansing quality and better preservation of submerged folds than the previous method, which was validated by the higher mean density values and fold preservation rates for manually segmented fold regions. View full abstract»

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  • Denoising MRI Using Spectral Subtraction

    Publication Year: 2013 , Page(s): 1556 - 1562
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1180 KB) |  | HTML iconHTML  

    Improving the signal-to-noise-ratio (SNR) of magnetic resonance imaging (MRI) using denoising techniques could enhance their value, provided that signal statistics and image resolution are not compromised. Here, a new denoising method based on spectral subtraction of the measured noise power from each signal acquisition is presented. Spectral subtraction denoising (SSD) assumes no prior knowledge of the acquired signal and does not increase acquisition time. Whereas conventional denoising/filtering methods are compromised in parallel imaging by spatially dependent noise statistics, SSD is performed on signals acquired from each coil separately, prior to reconstruction. Using numerical simulations, we show that SSD can improve SNR by up to ~45% in MRI reconstructed from both single and array coils, without compromising image resolution. Application of SSD to phantom, human heart, and brain MRI achieved SNR improvements of ~40% compared to conventional reconstruction. Comparison of SSD with anisotropic diffusion filtering showed comparable SNR enhancement at low-SNR levels (SNR = 5-15) but improved accuracy and retention of structural detail at a reduced computational load. View full abstract»

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  • Confidence-Based Rejection for Improved Pattern Recognition Myoelectric Control

    Publication Year: 2013 , Page(s): 1563 - 1570
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1073 KB) |  | HTML iconHTML  

    This study describes a novel myoelectric control scheme that is capable of motion rejection. As an extension of the commonly used linear discriminant analysis (LDA), this system generates a confidence score for each decision, providing the ability to reject those with a score below a selected threshold. The thresholds are class-specific and affect only the rejection characteristics of the associated class. Furthermore, because the rejection stage is implemented using the outputs of the LDA, the active motion classification accuracy of the proposed system is shown to outperform that of the LDA for all values of rejection threshold. The proposed scheme was compared to a baseline LDA-based pattern recognition system using a real-time Fitts' law-based target acquisition task. The use of velocity-based myoelectric control using the rejection classifier is shown to obey Fitts' law, producing linear regression fittings with high coefficients of determination (R2 > 0.943). Significantly higher (p <; 0.001) throughput, path efficiency, and completion rates were observed with the rejection-capable system for both able-bodied and amputee subjects. View full abstract»

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  • Photon Efficiency Optimization in Time-Correlated Single Photon Counting Technique for Fluorescence Lifetime Imaging Systems

    Publication Year: 2013 , Page(s): 1571 - 1579
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (687 KB) |  | HTML iconHTML  

    In time-correlated single photon counting (TCSPC) systems, the maximum signal throughput is limited by the occurrence of pile-up and other effects. In many biological applications that exhibit high levels of fluorescence intensity (FI), pile-up-related distortions yield serious distortions in the fluorescence lifetime (FLT) calculation as well as significant decrease in the signal-to-noise ratio (SNR). Recent developments that allow the use of high-repetition-rate light sources (in the range of 50-100 MHz) in fluorescence lifetime imaging (FLIM) experiments enable minimization of pile-up-related distortions. However, modern TCSPC configurations that use high-repetition-rate excitation sources for FLIM suffer from dead-time-related distortions that cause unpredictable distortions of the FI signal. In this study, the loss of SNR is described by F- value as it is typically done in FLIM systems. This F-value describes the relation of the relative standard deviation in the estimated FLT to the relative standard deviation in FI measurements. Optimization of the F-value allows minimization of signal distortion, as well as shortening of the acquisition time for certain samples. We applied this method for Fluorescein, Rhodamine B, and Erythrosine fluorescent solutions that have different FLT values (4 ns, 1.67 ns, and 140 ps, respectively). View full abstract»

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  • Novel Bayesian Vectorcardiographic Loop Alignment for Improved Monitoring of ECG and Fetal Movement

    Publication Year: 2013 , Page(s): 1580 - 1588
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (783 KB) |  | HTML iconHTML  

    The continuous analysis of electrocardiographic (ECG) signals is complicated by morphological variability in the ECG due to movement of the heart. By aligning vectorcardiographic loops, movement-induced ECG variations can be partly corrected for. Existing methods for loop alignment can account for loop rotation, scaling, and time delays, but they lack the possibility to include a priori information on any of these transformations, and they are unreliable in case of low-quality signals, such as fetal ECG signals. The inclusion of a priori information might aid in the robustness of loop alignment and is, hence, proposed in this paper. We provide a generic Bayesian framework to derive our loop alignment method. In this framework, existing methods can be readily derived as well, as a simplification of our method. The loop alignment is evaluated by comparing its performance in loop alignment to two existing methods, for both adult and fetal ECG recordings. For the adult ECG recordings, a quantitative performance assessment shows that the developed method outperforms the existing method in terms of robustness. For the fetal ECG recordings, it is demonstrated that the developed method can be used to correct ECG signals for movement-induced morphology changes (enabling diagnostics) and that the method is capable of classifying recorded ECG signals to periods of fetal movement or rest (p <; 0.01). This information on fetal movement can also serve as a valuable diagnostic tool. View full abstract»

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  • A Variational Surface Deformation and Subdivision-Based Modeling Framework for Noisy and Small n-Furcated Tube-Like Structures

    Publication Year: 2013 , Page(s): 1589 - 1598
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (6211 KB) |  | HTML iconHTML  

    It is challenging to construct an accurate and smooth mesh for noisy and small n-furcated tube-like structures, such as arteries, veins, and pathological vessels, due to tiny vessel size, noise, n -furcations, and irregular shapes of pathological vessels. We propose a framework by dividing the modeling process into mesh construction and mesh refinement. In the first step, we focus on mesh topological correctness, and just create an initial rough mesh for the n-furcated tube-like structures. In the second step, we propose a variational surface deformation method to push the initial mesh to structure boundaries for positional accuracy improvement. By iteratively solving Euler-Lagrange equations derived from the minimization of the shell and distance energies, the initial mesh can be gradually pushed to the boundaries. A mesh dilation method is proposed to prevent the extremely deviated initial mesh moving toward wrong boundaries. We combine deformation and subdivision to propose a coarse-to-fine modeling framework for the improvement of efficiency and accuracy. Experiments show our method can construct an accurate and smooth mesh for noisy and small n-furcated tube-like structures, and it is useful in hemodynamics, quantitative measurement, and analysis of vessels. View full abstract»

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  • Optimization of Mechanical Ventilator Settings for Pulmonary Disease States

    Publication Year: 2013 , Page(s): 1599 - 1607
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (903 KB) |  | HTML iconHTML  

    The selection of mechanical ventilator settings that ensure adequate oxygenation and carbon dioxide clearance while minimizing the risk of ventilator-associated lung injury (VALI) is a significant challenge for intensive-care clinicians. Current guidelines are largely based on previous experience combined with recommendations from a limited number of in vivo studies whose data are typically more applicable to populations than to individuals suffering from particular diseases of the lung. By combining validated computational models of pulmonary pathophysiology with global optimization algorithms, we generate in silico experiments to examine current practice and uncover optimal combinations of ventilator settings for individual patient and disease states. Formulating the problem as a multiobjective, multivariable constrained optimization problem, we compute settings of tidal volume, ventilation rate, inspiratory/expiratory ratio, positive end-expiratory pressure and inspired fraction of oxygen that optimally manage the tradeoffs between ensuring adequate oxygenation and carbon dioxide clearance and minimizing the risk of VALI for different pulmonary disease scenarios. View full abstract»

    Open Access
  • Ultrasound-Guided Characterization of Interstitial Ablated Tissue Using RF Time Series: Feasibility Study

    Publication Year: 2013 , Page(s): 1608 - 1618
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1198 KB) |  | HTML iconHTML  

    This paper presents the results of a feasibility study to demonstrate the application of ultrasound RF time series imaging to accurately differentiate ablated and nonablated tissue. For 12 ex vivo and two in situ tissue samples, RF ultrasound signals are acquired prior to, and following, high-intensity ultrasound ablation. Spatial and temporal features of these signals are used to characterize ablated and nonablated tissue in a supervised-learning framework. In cross-validation evaluation, a subset of four features extracted from RF time series produce a classification accuracy of 84.5%, an area under ROC curve of 0.91 for ex vivo data, and an accuracy of 85% for in situ data. Ultrasound RF time series is a promising approach for characterizing ablated tissue. View full abstract»

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  • Motion of the Kidney Between Preoperative and Intraoperative Positioning

    Publication Year: 2013 , Page(s): 1619 - 1627
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (477 KB) |  | HTML iconHTML  

    For many laparoscopic surgical procedures, the preoperative images are taken with the patient in a different position than that in which the surgery is performed. The organ shift between positions can affect surgical image guidance, as the organ shifts can complicate image registration. In particular, for partial nephrectomy, the standard clinical approach requires supine preoperative computed tomography, while the surgery is performed in the flank position. We studied ten subjects in both supine and flank positions. Rigid registration was used to determine the relative motion of the kidneys, using the spine as a pose-independent landmark. Our results showed that the kidney can move as much as 46.5 mm as a result of a supine-to-flank change in patient position, and rotate as much as 25°. From the results, significant kidney motion occurs due to the change of patient position from supine to flank. These changes warrant further study to understand and model the patient specific motion. View full abstract»

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  • A Reconfigurable Digital Filterbank for Hearing-Aid Systems With a Variety of Sound Wave Decomposition Plans

    Publication Year: 2013 , Page(s): 1628 - 1635
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (931 KB) |  | HTML iconHTML  

    Current hearing-aid systems have fixed sound wave decomposition plans due to the use of fixed filterbanks, thus cannot provide enough flexibility for the compensation of different hearing impairment cases. In this paper, a reconfigurable filterbank that consists of a multiband-generation block and a subband-selection block is proposed. Different subbands can be produced according to the control parameters without changing the structure of the filterbank system. The use of interpolation, decimation, and frequency-response masking enables us to reduce the computational complexity by realizing the entire system with only three prototype filters. Reconfigurability of the proposed filterbank enables hearing-impaired people to customize hearing aids based on their own specific conditions to improve their hearing ability. We show, by means of examples, that the proposed filterbank can achieve a better matching to the audiogram and has smaller complexity compared with the fixed filterbank. The drawback of the proposed method is that the throughput delay is relatively long (>20 ms), which needs to be further reduced before it can be used in a real hearing-aid application. View full abstract»

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  • Effects of Robotic Knee Exoskeleton on Human Energy Expenditure

    Publication Year: 2013 , Page(s): 1636 - 1644
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (693 KB) |  | HTML iconHTML  

    A number of studies discuss the design and control of various exoskeleton mechanisms, yet relatively few address the effect on the energy expenditure of the user. In this paper, we discuss the effect of a performance augmenting exoskeleton on the metabolic cost of an able-bodied user/pilot during periodic squatting. We investigated whether an exoskeleton device will significantly reduce the metabolic cost and what is the influence of the chosen device control strategy. By measuring oxygen consumption, minute ventilation, heart rate, blood oxygenation, and muscle EMG during 5-min squatting series, at one squat every 2 s, we show the effects of using a prototype robotic knee exoskeleton under three different noninvasive control approaches: gravity compensation approach, position-based approach, and a novel oscillator-based approach. The latter proposes a novel control that ensures synchronization of the device and the user. Statistically significant decrease in physiological responses can be observed when using the robotic knee exoskeleton under gravity compensation and oscillator-based control. On the other hand, the effects of position-based control were not significant in all parameters although all approaches significantly reduced the energy expenditure during squatting. View full abstract»

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  • Development of a Wireless Sensor for the Measurement of Chicken Blood Flow Using the Laser Doppler Blood Flow Meter Technique

    Publication Year: 2013 , Page(s): 1645 - 1653
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1866 KB) |  | HTML iconHTML  

    Here, we report the development of an integrated laser Doppler blood flow micrometer for chickens. This sensor weighs only 18 g and is one of the smallest-sized blood flow meters, with no wired line, these are features necessary for attaching the sensor to the chicken. The structure of the sensor chip consists of two silicon cavities with a photo diode and a laser diode, which was achieved using the microelectromechanical systems technique, resulting in its small size and significantly low power consumption. In addition, we introduced an intermittent measuring arrangement in the measuring system to reduce power consumption and to enable the sensor to work longer. We were successfully able to measure chicken blood flow for five consecutive days, and discovered that chicken blood flow shows daily fluctuations. View full abstract»

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  • The Use of a Bone-Anchored Device as a Hard-Wired Conduit for Transmitting EMG Signals From Implanted Muscle Electrodes

    Publication Year: 2013 , Page(s): 1654 - 1659
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (431 KB) |  | HTML iconHTML  

    The use of a bone-anchored device to transmit electrical signals from internalized muscle electrodes was studied in a sheep model. The bone-anchored device was used as a conduit for the passage of a wire connecting an internal epimysial electrode to an external signal-recording device. The bone-anchored device was inserted into an intact tibia and the electrode attached to the adjacent M. peroneus tertius. “Physiological” signals with low signal-to-noise ratios were successfully obtained over a 12-week period by walking the sheep on a treadmill. Reliable transmission of multiple muscle signals across the skin barrier is essential for providing intuitive, biomimetic upper limb prostheses. This technology has the potential to provide a better functional and reliable solution for upper limb amputee rehabilitation: attachment and control. View full abstract»

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  • ECG Signal Quality During Arrhythmia and Its Application to False Alarm Reduction

    Publication Year: 2013 , Page(s): 1660 - 1666
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (555 KB) |  | HTML iconHTML  

    An automated algorithm to assess electrocardiogram (ECG) quality for both normal and abnormal rhythms is presented for false arrhythmia alarm suppression of intensive care unit (ICU) monitors. A particular focus is given to the quality assessment of a wide variety of arrhythmias. Data from three databases were used: the Physionet Challenge 2011 dataset, the MIT-BIH arrhythmia database, and the MIMIC II database. The quality of more than 33 000 single-lead 10 s ECG segments were manually assessed and another 12 000 bad-quality single-lead ECG segments were generated using the Physionet noise stress test database. Signal quality indices (SQIs) were derived from the ECGs segments and used as the inputs to a support vector machine classifier with a Gaussian kernel. This classifier was trained to estimate the quality of an ECG segment. Classification accuracies of up to 99% on the training and test set were obtained for normal sinus rhythm and up to 95% for arrhythmias, although performance varied greatly depending on the type of rhythm. Additionally, the association between 4050 ICU alarms from the MIMIC II database and the signal quality, as evaluated by the classifier, was studied. Results suggest that the SQIs should be rhythm specific and that the classifier should be trained for each rhythm call independently. This would require a substantially increased set of labeled data in order to train an accurate algorithm. View full abstract»

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Aims & Scope

IEEE Transactions on Biomedical Engineering contains basic and applied papers dealing with biomedical engineering. Papers range from engineering development in methods and techniques with biomedical applications to experimental and clinical investigations with engineering contributions.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Bin He
Department of Biomedical Engineering