Prediction of apoptosis protein subcellular location based on position-specific scoring matrix and isometric mapping algorithm
AbstractApoptosis proteins are related to many diseases. Obtaining the subcellular localization information of apoptosis proteins is helpful to understand the mechanism of diseases and to develop new drugs. At present, the researchers mainly focus on the primary protein sequences, so there is still room for improvement in the prediction accuracy of the subcellular localization of apoptosis proteins. In this paper, a new method named ERT-ECT-PSSM-IS is proposed to predict apoptosis proteins based on the position-specific scoring matrix (PSSM). First, the local and global features of different directions are extracted by evo...
Source: Medical and Biological Engineering and Computing - October 16, 2019 Category: Biomedical Engineering Source Type: research

Using game controller as position tracking sensor for 3D freehand ultrasound imaging
AbstractPosition tracking has been widely used in medical applications, especially in 3D ultrasound imaging, where it has transformed the 2D slice limitation into 3D volume with bigger clinical impacts. As a game controller can also produce position tracking information, it has the potential to act as a low-cost and portable position tracker for ultrasound probes. This paper aims to investigate the feasibility of a game controller to perform as a position tracker and to design its implementation in 3D ultrasound imaging. The study consists of data acquisition and 3D ultrasound reconstruction for visualization. The data acq...
Source: Medical and Biological Engineering and Computing - October 10, 2019 Category: Biomedical Engineering Source Type: research

GSIAR: gene-subcategory interaction-based improved deep representation learning for breast cancer subcategorical analysis using gene expression, applicable for precision medicine
AbstractTumor subclass detection and diagnosis is inevitable requirement for personalized medical treatment and refinement of the effects that the somatic cells show towards other clinical conditions. The genome of these somatic cells exhibits mutations and genetic variations of the breast cancer cells and helps in understanding the characteristic behavior of the cancer cells. But their analysis is limited to clustering and there is requirement to analyze what else can be done with the data for identifying the tumor subcategory and the stages of subclasses. In this work, we have extended the work with similar data (consist...
Source: Medical and Biological Engineering and Computing - October 7, 2019 Category: Biomedical Engineering Source Type: research

Direct comparison of supervised and semi-supervised retraining approaches for co-adaptive BCIs
AbstractFor Brain-Computer interfaces (BCIs), system calibration is a lengthy but necessary process for successful operation. Co-adaptive BCIs aim to shorten training and imply positive motivation to users by presenting feedback already at early stages: After just 5  min of gathering calibration data, the systems are able to provide feedback and engage users in a mutual learning process. In this work, we investigate whether the retraining stage of co-adaptive BCIs can be adapted to a semi-supervised concept, where only a small amount of labeled data is availab le and all additional data needs to be labeled by the BCI ...
Source: Medical and Biological Engineering and Computing - September 14, 2019 Category: Biomedical Engineering Source Type: research

Long-term hemodynamic mechanism of enhanced external counterpulsation in the treatment of coronary heart disease: a geometric multiscale simulation
AbstractEnhanced external counterpulsation (EECP) is a noninvasive treatment method for coronary artery atherosclerosis that acts on the vascular endothelial cells. The intracoronary hemodynamic parameters that influence long-term treatment effect are the fundamental factors for the inhibition of intimal hyperplasia, which cannot be measured in real time. In order to optimize the long-term treatment effect of coronary heart disease, it is necessary to establish a method for quantified calculation of intracoronary hemodynamic parameters during counterpulsation to research the long-term hemodynamic mechanism of EECP. A geome...
Source: Medical and Biological Engineering and Computing - September 14, 2019 Category: Biomedical Engineering Source Type: research

Dispersion characterization of magnetic actuated needleless injections with particle image velocimetry
AbstractConventional needle-based approaches in intravitreal drug delivery carry needle-stick-injury risk and could scare patients (belonephobia). Alternatively, our group has explored the application of an electromagnetic needleless injector in this paper. This work aims to improve intravitreal drug delivery, which in the future could assist physicians with automation and benefit patients by providing a needleless approach. Electromagnetic needleless intravitreal injections lack quantification studies. We investigate the delivery properties of the needleless injector where the characterization can be used to refine the de...
Source: Medical and Biological Engineering and Computing - September 12, 2019 Category: Biomedical Engineering Source Type: research

Medical image encryption using fractional discrete cosine transform with chaotic function
AbstractIn this advanced era, where we have high-speed connectivity, it is very imperative to insulate medical data from forgery and fraud. With the regular increment in the number of internet users, it is challenging to transmit the beefy medical data. This (medical data) is always reused for different diagnosis purposes, so the information of the medical images need to be protected. This paper introduces a new scheme to ensure the safety of the medical data, which includes the use of a chaotic map on the fractional discrete cosine transform (FrDCT) coefficients of the medical data/images. The imperative FrDCT provides a ...
Source: Medical and Biological Engineering and Computing - September 11, 2019 Category: Biomedical Engineering Source Type: research

Effects of inclined surfaces on gait variability and stability in unilateral lower limb amputees
This study aims to analyze gait variability and stability of individuals with amputation walking on upward (8%), horizontal (0%), and downward ( − 8%) inclines, by using linear and nonlinear descriptors. Trunk linear variability and gait spatiotemporal parameters were evaluated. Nonlinear variability (local dynamic stability-LDS), was estimated by the maximum Lyapunov exponent (λ) computed from a trunk marker velocity. The gait descript ors were compared among three distinct groups (N participants): unilateral transtibial amputees (TTA,N = 12); unilateral transfemoral amputees (TFA,N&thins...
Source: Medical and Biological Engineering and Computing - September 10, 2019 Category: Biomedical Engineering Source Type: research

The synergetic effect of pelvic rotation and X-ray offset on radiographic angles of the acetabular cup
In this study, a cone model for three-dimensional circle-to-two-dimensional ellipse projection is utilized to incorporate the effect of X-ray offset and quantify the relationships of the radiographic angles of the cup with the true orientation of the cup and pelvic rotations in either pelvic or hip anteroposterior radiographic situation. (Source: Medical and Biological Engineering and Computing)
Source: Medical and Biological Engineering and Computing - September 9, 2019 Category: Biomedical Engineering Source Type: research

Advanced computing solutions for analysis of laryngeal disorders
AbstractClinical diagnosis of voice pathologies is performed by analyzing audio, color, shape, and vibration patterns of the laryngeal recordings which are taken with medical imaging devices such as video-laryngostroboscope, direct laryngoscopy, and high-speed videoendoscopes. This paper examines state-of-the-art methods and reveals open issues and problems of computing solutions for analysis and identification of laryngeal disorders. We propose a categorical representation of the most significant applications published so far in terms of their scopes, used methodologies, and achieved results. Laryngeal image/video analysi...
Source: Medical and Biological Engineering and Computing - September 6, 2019 Category: Biomedical Engineering Source Type: research

Real-time epileptic seizure prediction based on online monitoring of pre-ictal features
This study aims to propose a real-time low computational approach for the prediction of epileptic seizures and to present an efficient hardware implementation of this approach for portable prediction systems. Three levels of feature extraction are performed to characterize the pre-ictal activities of the EEG signal. In the first-level, the line length algorithm is applied to the pre-ictal region. The features obtained in the first-level are mathematically integrated to extract the second-level features and then the line lengths of the second-level features are calculated to obtain our third-level feature. The third-level i...
Source: Medical and Biological Engineering and Computing - September 2, 2019 Category: Biomedical Engineering Source Type: research

Feasibility study of portable microwave microstrip open-loop resonator for non-invasive blood glucose level sensing: proof of concept
AbstractSelf-management of blood glucose level is part and parcel of diabetes treatment, which involves invasive, painful, and uncomfortable methods. A proper non-invasive blood glucose monitor (NIBGM) is therefore desirable to deal better with it. Microwave resonators can potentially be used for such a purpose. Following the positive results from an in vitro previous work, a portable device based upon a microwave resonator was developed and assessed in a multicenter proof of concept. Its electrical response was analyzed when an individual ’s tongue was placed onto it. The study was performed with 352 individuals dur...
Source: Medical and Biological Engineering and Computing - August 31, 2019 Category: Biomedical Engineering Source Type: research

Badminton players show a lower coactivation and higher beta band intermuscular interactions of ankle antagonist muscles during isokinetic exercise
AbstractPrevious studies have suggested that skilled athletes may show a specific muscle activation pattern with a lower antagonist coactivation level. Based on the point, we hypothesize that the coupling of antagonistic muscles may be different between badminton players and non-skilled individuals during exercises. The current work was designed to verify the hypothesis. Ten male college students and eight male badminton players performed three maximal voluntary isometric contractions (MVC) and a set of three maximal concentric ankle dorsiflexion and plantar flexions at an angular velocity of 30 °, 60°, 120°, a...
Source: Medical and Biological Engineering and Computing - August 31, 2019 Category: Biomedical Engineering Source Type: research

Robust control of heart rate for cycle ergometer exercise
The objective was to assess the performance and robustness of a novel strategy for automatic control of heart rate (HR) during cycle ergometry. Control design used a linear plant model and direct shaping of the closed-loop input-sensitivity function to achieve an appropriate response to disturbances attributable to broad-spectrum heart rate variability (HRV). The controller was evaluated in 73 feedback control experiments involving 49 participants. Performance and stability robustness were analysed using a separately identified family of 73 plant models. The controller gave highly accurate and stable HR tracking performanc...
Source: Medical and Biological Engineering and Computing - August 30, 2019 Category: Biomedical Engineering Source Type: research

IMU-based sensor-to-segment multiple calibration for upper limb joint angle measurement —a proof of concept
AbstractA lot of attention has been paid to wearable inertial sensors regarded as an alternative solution for outdoor human motion tracking. Relevant joint angles can only be calculated from anatomical orientations, but they are negatively impacted by soft tissue artifact (STA) defined as skin motion with respect to the underlying bone; the accuracy of measured joint angle during movement is affected by the ongoing misalignment of the sensor. In this work, a new sensor-to-segment calibration using inertial measurement units is proposed. Inspired by the multiple calibration for a cluster of skin markers, it consists in perf...
Source: Medical and Biological Engineering and Computing - August 30, 2019 Category: Biomedical Engineering Source Type: research

Design a prototype for automated patient diagnosis in wireless sensor networks
AbstractIt is indeed necessary to design of an elderly support mobile healthcare and monitoring system on wireless sensor network (WSN) for dynamic monitoring. It comes from the need for maintenance of healthcare among patients and elderly people that leads to the demand on change in traditional monitoring approaches among chronic disease patients and alert on acute events. In this paper, we propose a new automated patient diagnosis called automated patient diagnosis (AUPA) using ATmega microcontrollers over environmental sensors. AUPA monitors and aggregates data from patients through network connected over web server and...
Source: Medical and Biological Engineering and Computing - August 29, 2019 Category: Biomedical Engineering Source Type: research

A new and effective method for human retina optic disc segmentation with fuzzy clustering method based on active contour model
AbstractIn this paper, a new approach is proposed for localization and segmentation of the optic disc in human retina images. This new approach can find the boundary of the optic disc by an initial fuzzy clustering means algorithm. The proposed approach uses active contour model evolution based on a fuzzy clustering algorithm. The robustness of the proposed approach was evaluated with retinal imaging medical databases, such as DRIVE, STARE, DIARETDB1, and DRIONS. These bases contained images affected by different abnormalities, for example, diabetes, retinitis pigmentosa, and age-related macular degeneration AMD. A success...
Source: Medical and Biological Engineering and Computing - August 24, 2019 Category: Biomedical Engineering Source Type: research

Accelerating cardiovascular model building with convolutional neural networks
The objective of this work is to reduce the user effort required for 2D segmentation when building patient-specific cardiovascular models using the SimVascular cardiovascular modeling software package. The proposed method uses a fully convolutional neural network (FCNN) to generate 2D cardiovascular segmentations. Given vessel pathlines, the neural network generates 2D vessel enhancement images along the pathlines. Thereafter, vessel segmentations are extracted using the marching-squares algorithm, which are then used to construct 3D cardiovascular models. The neural network is trained using a novel loss function, tailored...
Source: Medical and Biological Engineering and Computing - August 24, 2019 Category: Biomedical Engineering Source Type: research

Measurement of range of motions of L3-L4 healthy spine through offsetting reflective markers and in silico analysis of meshed model
AbstractDegenerative disc disease (DDD) is a common condition in elderly population that can be painful and can significantly affect individual ’s quality of life. Diagnosis of DDD allows prompt corrective actions but it is challenging due to the absence of any symptoms at early stages. In studying disc degeneration, measurement of the range of motion (RoM) and loads acting on the spine are crucial factors. However, direct measurement of RoM involves increased instrumentation and risk. In this paper, an innovative method is proposed for calculating RoM, emphasizing repeatability and reliability by considering the pos...
Source: Medical and Biological Engineering and Computing - August 23, 2019 Category: Biomedical Engineering Source Type: research

The Helitron family classification using SVM based on Fourier transform features applied on an unbalanced dataset
AbstractHelitrons are mobile sequences which belong to the class 2 of eukaryotic transposons. Their specificity resides in their mechanism of transposition: the rolling circle mechanism. They play an important role in remodeling proteomes due to their ability to modify existing genes and introducing new ones. A major difficulty in identifying and classifying Helitron families comes from the complex structure, the unspecified length, and the unbalanced appearance number of each Helitron type. The Helitron ’s recognition is still not solved in literature. The purpose of this paper is to characterize and classify Helitr...
Source: Medical and Biological Engineering and Computing - August 17, 2019 Category: Biomedical Engineering Source Type: research

An improved fuzzy-differential evolution approach applied to classification of tumors in liver CT scan images
This article takes advantages of differential evolutionary algorithm to search the problem space more intelligently using the knowledge of distance vector of the candidate solutions. For this, a hybrid fuzzy-DE model has been proposed for the problem of classification of the Haptic metastasis tumors through information obtained from the features measured in the CT scan images by radiologists. The hybrid fuzzy-DE model was evaluated using a real liver cancer dataset obtained from the Noor medical imaging center in Tehran. The results of the hybrid proposed models were compared with the diagnosis of the specialists, the resu...
Source: Medical and Biological Engineering and Computing - August 15, 2019 Category: Biomedical Engineering Source Type: research

A sum-modified-Laplacian and sparse representation based multimodal medical image fusion in Laplacian pyramid domain
AbstractFusion of multimodal medical images provides complementary information for diagnosis, surgical planning, and clinical outcome evaluation. Although the multiscale decomposition –based fusion methods have attracted much attention among researchers, the challenges of determining the decomposition levels and the loss of contrast hindered their applications. Here, we present a multimodal medical images fusion method combining the sum-modified-Laplacian (SML) with sparse repr esentation (SR) in the Laplacian pyramid domain. In this method, we first transformed the original images into the high-pass and low-pass ban...
Source: Medical and Biological Engineering and Computing - August 14, 2019 Category: Biomedical Engineering Source Type: research

Potentiation of the first and second phases of the M wave after maximal voluntary contractions in the biceps brachii muscle
AbstractThe study was undertaken to examine separately the potentiation of the first and second phases of the M wave inbiceps brachii after conditioning maximal voluntary contractions (MVCs) of different durations. M waves were evoked in thebiceps brachii muscle before and after isometric MVCs of 1, 3, 6, 10, 30, and 60  s. The amplitude, duration, and area of the first and second phases of monopolar M waves were measured during the 10-min period following each contraction. Our results indicated that the amplitude and area of the M-wave first phase increased after MVCs of long (≥ 30 s) duration (P 
Source: Medical and Biological Engineering and Computing - August 13, 2019 Category: Biomedical Engineering Source Type: research

An adaptive enhancement method for breast X-ray images based on the nonsubsampled contourlet transform domain and whale optimization algorithm
AbstractWe propose a new method for breast X-ray image adaptive enhancement that combines nonsubsampled contourlet transform (NSCT) with the whale optimization algorithm (WOA). First, the mammography X-ray image was processed by histogram equalization to ensure global image contrast. The processed image was then decomposed into three layers in the NSCT domain. Each layer was each decomposed into two, four, and eight directions. A median filter was used to remove noise in the first and second layers. Then, a special edge filter was adopted to enhance each sub-band image, and two parameters are involved. WOA is used to autom...
Source: Medical and Biological Engineering and Computing - August 13, 2019 Category: Biomedical Engineering Source Type: research

Evidence-based medical equipment management: a convenient implementation
In this study, a novel set of key performance indicators is also proposed for evaluating medical equipment maintenance performance. The purpose of this research is to combine these two evidence-based methods to assess every aspect of the maintenance process and provide an objective and standardized approach that will support and enhance clinical engineering activities. Starting from the evidence (i.e. failures), the results show that the combination of these t wo methods can provide a periodical cross-analysis of maintenance performance that indicates the most appropriate procedures.Graphical abstractThe left side shows a ...
Source: Medical and Biological Engineering and Computing - August 10, 2019 Category: Biomedical Engineering Source Type: research

Improving the power of objective response detection of evoked responses in noise by using average and product of magnitude-squared coherence of two different signals
AbstractObjective response detection (ORD) techniques such as the magnitude-squared coherence (MSC) are mathematical methods tailored to detect potentials evoked by an external periodic stimulation. The performance of the MSC is directly proportional to the signal-to-noise ratio (SNR) of the recorded signal and the time spent for collecting data. An alternative to increasing the performance of detection techniques without increasing data recording time is to use the information from more than one signal simultaneously. In this context, this work proposes two new detection techniques based on the average and on the product ...
Source: Medical and Biological Engineering and Computing - August 9, 2019 Category: Biomedical Engineering Source Type: research

A cepstrum analysis-based classification method for hand movement surface EMG signals
AbstractIt is of great importance to effectively process and interpret surface electromyogram (sEMG) signals to actuate a robotic and prosthetic exoskeleton hand needed by hand amputees. In this paper, we have proposed a cepstrum analysis-based method for classification of basic hand movement sEMG signals. Cepstral analysis technique primarily used for analyzing acoustic and seismological signals is effectively exploited to extract features of time-domain sEMG signals by computing mel-frequency cepstral coefficients (MFCCs). The extracted feature vector consisting of MFCCs is then forwarded to feed a generalized regression...
Source: Medical and Biological Engineering and Computing - August 7, 2019 Category: Biomedical Engineering Source Type: research

Transversely isotropic and isotropic material considerations in determining the mechanical response of geometrically accurate bovine tibia bone
AbstractIn finite element method (FEM) simulations of the mechanical response of bones, proper selection of stiffness versus density (E- ρ) formulae for bone constituents is necessary for obtaining accurate results. A considerable number of such formulae can be found in the biomechanics’ literature covering both cortical and cancellous constituents. For determining the first and second modal frequencies (in both cranial-caudal and medial-lateral planes) of bovine tibia bone, this work assembled and numerically tested 22 isotropic and 21 orthotropic stiffness-density formulae combinations (cases). To accurately re...
Source: Medical and Biological Engineering and Computing - August 3, 2019 Category: Biomedical Engineering Source Type: research

Reconstruction of compressively sampled MR images based on a local shrinkage thresholding algorithm with curvelet transform
AbstractTo reduce the magnetic resonance imaging (MRI) data acquisition time and improve the MR image reconstruction performance, reconstruction algorithms based on the iterative shrinkage thresholding algorithm (ISTA) are widely used. However, these traditional algorithms use global threshold shrinkage, which is not efficient. In this paper, a novel algorithm based on local threshold shrinkage, which is called the local shrinkage thresholding algorithm (LSTA), was proposed. The LSTA can shrink differently for different elements from the residual matrix to adjust the shrinkage speed for each element of the image during the...
Source: Medical and Biological Engineering and Computing - August 3, 2019 Category: Biomedical Engineering Source Type: research

Biomechanical modeling of transcatheter aortic valve replacement in a stenotic bicuspid aortic valve: deployments and paravalvular leakage
This study aims to develop refined computational models simulating the deployments of Evolut R and PRO TAVR devices in a representative calcified BAV. The paravalvular leakage (PVL) was also calculated by computational fluid dynamics simulations. Computed tomography scan of severely stenotic BAV patient was acquired. The 3D calcium deposits were generated and embedded inside a parametric model of the BAV. Deployments of the Evolut R and PRO inside the calcified BAV were simulated in five bioprosthesis leaflet orientations. The hypothesis of asymmetric and elliptic stent deployment was confirmed. Positioning the bioprosthes...
Source: Medical and Biological Engineering and Computing - August 1, 2019 Category: Biomedical Engineering Source Type: research

A semi-automatic 3D ultrasound reconstruction method to assess the true severity of adolescent idiopathic scoliosis
AbstractAdolescent idiopathic scoliosis (AIS) is a three-dimensional (3D) spinal deformity. Current practice uses the Cobb method to measure spinal severity on postero-anterior (PA) radiographs. This method may underestimate spinal deformity and exposes patients to ionizing radiation, increasing the risk of cancer. This paper reports a new 3D ultrasound method using the voxel-based reconstruction technique with bilinear interpolation to reconstruct a 3D spinal image and measure true spinal curvature on the plane of maximal curvature (PMC). Axial vertebral rotation (AVR) was measured on the 3D image and utilized to estimate...
Source: Medical and Biological Engineering and Computing - July 31, 2019 Category: Biomedical Engineering Source Type: research

ML and MAP estimation of parameters for the Kalman filter and smoother applied to electrocardiographic imaging
AbstractIn electrocardiographic imaging (ECGI), one solves the inverse problem of electrocardiography (ECG) to reconstruct equivalent cardiac sources based on the body surface potential measurements and a mathematical model of the torso. Due to attenuation and spatial smoothing within the torso, this inverse problem is ill-posed. Among many regularization approaches used in the ECG literature to overcome this ill-posedness, statistical techniques have received great attention because of their flexibility to represent the data, and ability to provide performance evaluation tools for quantification of uncertainties and error...
Source: Medical and Biological Engineering and Computing - July 30, 2019 Category: Biomedical Engineering Source Type: research

Aortic root sizing for transcatheter aortic valve implantation using a shape model parameterisation
AbstractDuring a transcatheter aortic valve implantation, an axisymmetric implant is placed in an irregularly shaped aortic root. Implanting an incorrect size can cause complications such as leakage of blood alongside or through the implant. The aim of this study was to construct a method that determines the optimal size of the implant based on the three-dimensional shape of the aortic root. Based on the pre-interventional computed tomography scan of 89 patients, a statistical shape model of their aortic root was constructed. The weights associated with the principal components and the volume of calcification in the aortic...
Source: Medical and Biological Engineering and Computing - July 29, 2019 Category: Biomedical Engineering Source Type: research

Adaptive weighted locality-constrained sparse coding for glaucoma diagnosis
AbstractGlaucoma is a sight-threading disease which can lead to irreversible blindness. Currently, extracting the vertical cup-to-disc ratio (CDR) from 2D retinal fundus images is promising for automatic glaucoma diagnosis. In this paper, we present a novel sparse coding approach for glaucoma diagnosis called adaptive weighted locality-constrained sparse coding (AWLCSC). Different from the existing reconstruction-based glaucoma diagnosis approaches, the weighted matrix in AWLCSC is constructed by adaptively fusing multiple distance measurement information between the reference images and the testing image, making our appro...
Source: Medical and Biological Engineering and Computing - July 27, 2019 Category: Biomedical Engineering Source Type: research

Evaluation of divided attention using different stimulation models in event-related potentials
AbstractDivided attention is defined as focusing on different tasks at once, and this is described as one of the biggest problems of today ’s society. Default examinations for understanding attention are questionnaires or physiological signals, like evoked potentials and electroencephalography. Physiological records were obtained using visual, auditory, and auditory-visual stimuli combinations with 48 participants—18-25-year-old un iversity students—to find differences between sustained and divided attention. A Fourier-based filter was used to get a 0.01–30-Hz frequency band. Fractal dimensions, ent...
Source: Medical and Biological Engineering and Computing - July 27, 2019 Category: Biomedical Engineering Source Type: research

Single channel surface electromyogram deconvolution to explore motor unit discharges
AbstractInterference surface electromyogram (EMG) reflects many bioelectric properties of active motor units (MU), which are however difficult to estimate due to the asynchronous summation of their discharges. This paper introduces a deconvolution technique to estimate the cumulative firings of MUs. Tests in simulations show that the power spectral density of the estimated MU firings has a low-frequency peak corresponding to the mean firing rate of MUs in the detection volume of the recording system, weighted by the amplitudes of MU action potentials. The peak increases in amplitude and its centroid shifts to a higher freq...
Source: Medical and Biological Engineering and Computing - July 27, 2019 Category: Biomedical Engineering Source Type: research

A deep learning algorithm for one-step contour aware nuclei segmentation of histopathology images
AbstractThis paper addresses the task of nuclei segmentation in high-resolution histopathology images. We propose an automatic end-to-end deep neural network algorithm for segmentation of individual nuclei. A nucleus-boundary model is introduced to predict nuclei and their boundaries simultaneously using a fully convolutional neural network. Given a color-normalized image, the model directly outputs an estimated nuclei map and a boundary map. A simple, fast, and parameter-free post-processing procedure is performed on the estimated nuclei map to produce the final segmented nuclei. An overlapped patch extraction and assembl...
Source: Medical and Biological Engineering and Computing - July 26, 2019 Category: Biomedical Engineering Source Type: research

Identification of clinically relevant features in hypertensive patients using penalized regression: a case study of cardiovascular events
AbstractAppropriate management of hypertensive patients relies on the accurate identification of clinically relevant features. However, traditional statistical methods may ignore important information in datasets or overlook possible interactions among features. Machine learning may improve the prediction accuracy and interpretability of regression models by identifying the most relevant features in hypertensive patients. We sought the most relevant features for prediction of cardiovascular (CV) events in a hypertensive population. We used the penalized regression models least absolute shrinkage and selection operator (LAS...
Source: Medical and Biological Engineering and Computing - July 25, 2019 Category: Biomedical Engineering Source Type: research

A vascular interventional surgical robot based on surgeon ’s operating skills
This study first evaluates the force-position control strategy using a vascular model experiment, and then an in vivo experiment is used to evaluate the precision of the surgical robot controlling the catheter and guidewire to the designated position. The in vivo experiment results and surgeon ’s feedback demonstrate that the proposed surgical robot is able to perform complex remote surgery in clinical application.Graphical abstractSurgeons perform remote interventional animal surgery using interventional surgical robots. (Source: Medical and Biological Engineering and Computing)
Source: Medical and Biological Engineering and Computing - July 25, 2019 Category: Biomedical Engineering Source Type: research

Unbiased groupwise registration for shape prediction of foot scans
AbstractA 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 i...
Source: Medical and Biological Engineering and Computing - July 20, 2019 Category: Biomedical Engineering Source Type: research

Leveraging network analysis to support experts in their analyses of subjects with MCI and AD
AbstractIn this paper, we propose a network analysis –based approach to help experts in their analyses of subjects with mild cognitive impairment (hereafter, MCI) and Alzheimer’s disease (hereafter, AD) and to investigate the evolution of these subjects over time. The inputs of our approach are the electroencephalograms (hereafter, EEGs) of the pa tients to analyze, performed at a certain time and, again, 3 months later. Given an EEG of a subject, our approach constructs a network with nodes that represent the electrodes and edges that denote connections between electrodes. Then, it applies several network-base...
Source: Medical and Biological Engineering and Computing - July 12, 2019 Category: Biomedical Engineering Source Type: research

Bypassing the volume conduction effect by multilayer neural network for effective connectivity estimation
In this study, we address the problem by jointly modeling the causal relationships among brain regions and the mixing effects of volume conduction. The VC effect is formulated with a time-invariant linear equation, and the causal relationships between the brain regions are modeled with a nonlinear multivariate autoregressive process. These two models are simultaneously implemented by a multilayer neural network. The internal hidden layers represent the interactions among the regions, while the external layers are devoted for the relationship between the source activities and observed EEG measurements at the scalp. The caus...
Source: Medical and Biological Engineering and Computing - July 4, 2019 Category: Biomedical Engineering Source Type: research

Orthogonal tensor dictionary learning for accelerated dynamic MRI
AbstractA direct application of the compressed sensing (CS) theory to dynamic magnetic resonance imaging (MRI) reconstruction needs vectorization or matricization of the dynamic MRI data, which is composed of a stack of 2D images and can be naturally regarded as a tensor. This 1D/2D model may destroy the inherent spatial structure property of the data. An alternative way to exploit the multidimensional structure in dynamic MRI is to employ tensor decomposition for dictionary learning, that is, learning multiple dictionaries along each dimension (mode) and sparsely representing the multidimensional data with respect to the ...
Source: Medical and Biological Engineering and Computing - June 28, 2019 Category: Biomedical Engineering Source Type: research

An iterative damped least-squares algorithm for simultaneously monitoring the development of hemorrhagic and secondary ischemic lesions in brain injuries
AbstractElectrical impedance tomography (EIT) is a non-invasive and real-time imaging method that has the potential to be used for monitoring intracerebral hemorrhage (ICH). Recent studies have proposed that ischemia secondary to ICH occurs simultaneously in the brain. Real-time monitoring of the development of hemorrhage and risk of secondary ischemia is crucial for clinical intervention. However, few studies have explored the performance of EIT monitoring in cases where hemorrhage and secondary ischemia exist. When these lesions get close to each other, or their conductivity and volume changes differ greatly, it becomes ...
Source: Medical and Biological Engineering and Computing - June 27, 2019 Category: Biomedical Engineering Source Type: research

Estimation of microvascular perfusion after esophagectomy: a quantitative model of dynamic fluorescence imaging
AbstractMost common complications of esophagectomy stem from a perfusion deficiency of the gastric conduit at the anastomosis. Fluorescent tracer imaging allows intraoperative visualization of tissue perfusion. Quantitative assessment of fluorescence dynamics has the potential to identify perfusion deficiency. We developed a perfusion model to analyze the relation between fluorescence dynamics and perfusion deficiency. The model divides the gastric conduit into two well-perfused and two anastomosed sites. Hemodynamics and tracer transport were modeled. We analyzed the value of relative time-to-threshold (RTT) as a predicto...
Source: Medical and Biological Engineering and Computing - June 26, 2019 Category: Biomedical Engineering Source Type: research

Optimized needle shape reconstruction using experimentally based strain sensors positioning
AbstractNeedles are tools that are used daily during minimally invasive procedures. During the insertions, needles may be affected by deformations which may threaten the success of the procedure. To tackle this problem, needles with embedded strain sensors have been developed and associated with navigation systems. The localization of the needle in the tissues is then obtained in real time by reconstruction from the strain measurements, allowing the physician to optimize its gesture. As the number of strain sensors embedded is limited in number, their positions on the needle have a great impact on the accuracy of the shape...
Source: Medical and Biological Engineering and Computing - June 26, 2019 Category: Biomedical Engineering Source Type: research

A CNN-based prototype method of unstructured surgical state perception and navigation for an endovascular surgery robot
AbstractPerformance of robot-assisted endovascular surgery (ES) remains highly dependent on an individual surgeon ’s skills, due to common adoption of master-slave robotic structure. Surgeons’ skill modeling and unstructured surgical state perception pose prohibitive challenges for an autonomous ES robot. In this paper, a novel convolutional neural network (CNN)-based framework is proposed to address these challenges for navigation of an ES robot based on surgeons’ skill learning. An operating action probability estimator is proposed by integrating a two-dimensional CNN, with which the features of a surgi...
Source: Medical and Biological Engineering and Computing - June 20, 2019 Category: Biomedical Engineering Source Type: research

Hemodynamic consequences of a multilayer flow modulator in aortic dissection
AbstractAortic dissections are challenging for it remains perplexing to determine when surgical, endovascular, or medical therapies are optimal. We studied the effect of the multilayer flow modulator (MFM) device in patients with different forms of type-B aortic dissections. CT scans were performed pre-, immediately post-MFM implantation, and multiple times within a 24-month follow-up. Three-dimensional reconstructions were created from these scans and the multilayer or single-layer mesh device placed virtually into the true lumen. We observed that MFM device can sufficiently restore flow perfusion, reduce the false lumen,...
Source: Medical and Biological Engineering and Computing - June 17, 2019 Category: Biomedical Engineering Source Type: research

Hybrid position/force output feedback second-order sliding mode control for a prototype of an active orthosis used in back-assisted mobilization
This article shows the design of a robust second-order sliding mode controller to solve the trajectory tracking problem of an active orthosis for assisting back physiotherapies. The orthosis was designed in agreement with morphological dimensions and its articulations distribution followed the same designing rules. The orthosis has six articulated arms attached to an articulated column. The orthosis was fully instrumented with actuators and position sensors at each articulation. The controller implemented a class of hybrid/position controller depending on the relative force exerted by the patient and the orthosis movement....
Source: Medical and Biological Engineering and Computing - June 17, 2019 Category: Biomedical Engineering Source Type: research

Intelligent prediction of kinetic parameters during cutting manoeuvres
AbstractDue to its capabilities in analysing injury risk, the ability to analyse an athlete ’s ground reaction force and joint moments is of high interest in sports biomechanics. However, using force plates for the kinetic measurements influences the athlete’s performance. Therefore, this study aims to use a feed-forward neural network to predict hip, knee and ankle joint moments as we ll as the ground reaction force from kinematic data during the execution and depart contact of a maximum effort 90° cutting manoeuvre. A total number of 525 cutting manoeuvres performed by 55 athletes were used to train and t...
Source: Medical and Biological Engineering and Computing - June 15, 2019 Category: Biomedical Engineering Source Type: research