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Medical & Biological Engineering & Computing

Tejaswi Ogirala, Ashley Eapen, Katrina G Salvante, Tomas Rapaport, Pablo A Nepomnaschy, Ash M Parameswaran
Biologists frequently collect and analyze biospecimens in naturalistic (i.e., field) conditions to ascertain information regarding the physiological status of their study participants. Generally, field-collected biospecimens need to be stored frozen in the field and then transported frozen to laboratory facilities where traditional biomarker assays, such as enzyme-linked immunosorbent assays (ELISAs), are conducted. As proper storage and transport of frozen specimens is often logistically difficult and expensive, particularly in nonurban field settings, methods that reduce the need for specimen storage and transport would benefit field-research dependent disciplines such as biology, ecology and epidemiology...
January 12, 2017: Medical & Biological Engineering & Computing
P Marsanic, A Mellano, A Sottile, M De Simone
In recent years, many local ablation technologies based on thermal damage have been used in the treatment of locally advanced pancreatic carcinoma (LAPC) and borderline resectable pancreatic carcinoma (BLRPC). However, they are associated with major complications because of possible vascular and ductal damage. Irreversible electroporation (IRE) is a nonthermal ablation technology that seems safe near vital vascular and ductal structures. IRE could be used as exclusive treatment of LAPC (en situ to IRE) after induction chemotherapy In BLRPC, surgery is not really radical in 6% of patients (microscopic residual) and local recurrences occur in 11-42% of apparent radical resections...
January 11, 2017: Medical & Biological Engineering & Computing
Youngjin Na, Sangjoon J Kim, Sungho Jo, Jung Kim
Previous pattern recognition algorithms using surface electromyography (sEMG) have been developed for subsets of predefined hand movements without considering muscle structure. In order to decode hand movements, it is important to know which movements are appropriate for PR due to the different independence of movements between individuals and the high correlated characteristics of sEMG patterns between movements. This paper proposes a method to personally rank the order of hand movements from subsets (31 finger flexion, 31 finger extension, and 4 wrist movements in this paper)...
January 4, 2017: Medical & Biological Engineering & Computing
Konstantinos Tzirakis, Yiannis Kamarianakis, Eleni Metaxa, Nikolaos Kontopodis, Christos V Ioannou, Yannis Papaharilaou
Longitudinal studies of vascular diseases often need to establish correspondence between follow-up images, as the diseased regions may change shape over time. In addition, spatial data structures should be taken into account in the statistical analyses to avoid inferential errors. This study investigates the association between hemodynamics and thrombus growth in abdominal aortic aneurysms (AAAs) while emphasizing on the abovementioned methodological issues. Six AAA surfaces and their follow-ups were three-dimensionally reconstructed from computed-tomography images...
January 2, 2017: Medical & Biological Engineering & Computing
Javad Tavakoli
The annulus fibrosus (AF) swelling property, which is correlated with its rheological and viscoelastic properties, plays a significant role in disc nutrition and mechanical loading justification during daily activities as well as designing scaffolds for tissue engineering applications. The objective of this study was twofold: firstly to characterize the AF single lamella swelling kinetics in different regions and solutions at the temperature range of 35-40 °C and secondly to use the swelling results as a baseline to model (independent to swelling media and anatomic region) the AF single lamella swelling...
January 2, 2017: Medical & Biological Engineering & Computing
Radovan Smíšek, Lucie Maršánová, Andrea Němcová, Martin Vítek, Jiří Kozumplík, Marie Nováková
Nowadays, cardiovascular diseases represent the most common cause of death in western countries. Among various examination techniques, electrocardiography (ECG) is still a highly valuable tool used for the diagnosis of many cardiovascular disorders. In order to diagnose a person based on ECG, cardiologists can use automatic diagnostic algorithms. Research in this area is still necessary. In order to compare various algorithms correctly, it is necessary to test them on standard annotated databases, such as the Common Standards for Quantitative Electrocardiography (CSE) database...
December 31, 2016: Medical & Biological Engineering & Computing
Li Wang, Yijun Feng, Ze Yang, Haijun Niu
Tone is important in tonal languages, especially in Mandarin. However, there is presently no commercially available electrolarynx (EL) for laryngectomized Mandarin speakers. Moreover, few studies have focused on this area. Our purpose is to design an EL that produces the four Mandarin tones and to evaluate its performance. We designed a wheel-controlled pitch-adjustable EL and manufactured a prototype (Wheel-EL). Using monosyllables, disyllabic segments, and frequently used phrases, we evaluated speech produced by Wheel-EL and by monotone (M-TruTone) and variable-frequency modes (V-TruTone) of the commercially available TruTone EL...
December 24, 2016: Medical & Biological Engineering & Computing
Sarfaraz Kamangar, Irfan Anjum Badruddin, Kalimuthu Govindaraju, N Nik-Ghazali, A Badarudin, Girish N Viswanathan, N J Salman Ahmed, T M Yunus Khan
The purpose of this study is to investigate the effect of various degrees of percentage stenosis on hemodynamic parameters during the hyperemic flow condition. 3D patient-specific coronary artery models were generated based on the CT scan data using MIMICS-18. Numerical simulation was performed for normal and stenosed coronary artery models of 70, 80 and 90% AS (area stenosis). Pressure, velocity, wall shear stress and fractional flow reserve (FFR) were measured and compared with the normal coronary artery model during the cardiac cycle...
December 21, 2016: Medical & Biological Engineering & Computing
Quan Liu, Yi-Feng Chen, Shou-Zen Fan, Maysam F Abbod, Jiann-Shing Shieh
Electroencephalography (EEG) has been widely utilized to measure the depth of anaesthesia (DOA) during operation. However, the EEG signals are usually contaminated by artifacts which have a consequence on the measured DOA accuracy. In this study, an effective and useful filtering algorithm based on multivariate empirical mode decomposition and multiscale entropy (MSE) is proposed to measure DOA. Mean entropy of MSE is used as an index to find artifacts-free intrinsic mode functions. The effect of different levels of artifacts on the performances of the proposed filtering is analysed using simulated data...
December 19, 2016: Medical & Biological Engineering & Computing
P Krishna Kumar, Tadashi Araki, Jeny Rajan, Luca Saba, Francesco Lavra, Nobutaka Ikeda, Aditya M Sharma, Shoaib Shafique, Andrew Nicolaides, John R Laird, Ajay Gupta, Jasjit S Suri
Monitoring of cerebrovascular diseases via carotid ultrasound has started to become a routine. The measurement of image-based lumen diameter (LD) or inter-adventitial diameter (IAD) is a promising approach for quantification of the degree of stenosis. The manual measurements of LD/IAD are not reliable, subjective and slow. The curvature associated with the vessels along with non-uniformity in the plaque growth poses further challenges. This study uses a novel and generalized approach for automated LD and IAD measurement based on a combination of spatial transformation and scale-space...
December 10, 2016: Medical & Biological Engineering & Computing
Carlos Rossa, Thomas Lehmann, Ronald Sloboda, Nawaid Usmani, Mahdi Tavakoli
Global modelling has traditionally been the approach taken to estimate needle deflection in soft tissue. In this paper, we propose a new method based on local data-driven modelling of needle deflection. External measurement of needle-tissue interactions is collected from several insertions in ex vivo tissue to form a cloud of data. Inputs to the system are the needle insertion depth, axial rotations, and the forces and torques measured at the needle base by a force sensor. When a new insertion is performed, the just-in-time learning method estimates the model outputs given the current inputs to the needle-tissue system and the historical database...
December 10, 2016: Medical & Biological Engineering & Computing
Alireza Rezvani-Sharif, Mohammad Tafazzoli-Shadpour, Davood Kazemi-Saleh, Maryam Sotoudeh-Anvari
Traditionally, the degree of luminal obstruction has been used to assess the vulnerability of atherosclerotic plaques. However, recent studies have revealed that other factors such as plaque morphology, material properties of lesion components and blood pressure may contribute to the fracture of atherosclerotic plaques. The aim of this study was to investigate the mechanism of fracture of atherosclerotic plaques based on the mechanical stress distribution and fatigue analysis by means of numerical simulation...
December 9, 2016: Medical & Biological Engineering & Computing
Wookjin Lee, Gyu Jin Choi, Seong Wook Cho
Atherosclerosis is one of the leading causes of death in the world. In this study, an idealized 2D plaque model based on plaque classification in the coronary artery is developed. When creating the idealized 2D model for each plaque type (fibrocalcic, FC; fibrofatty, FT; calcified fibroatheroma, CaFA; fibroatheroma, FA; calcified thin-cap fibroatheroma, CaTCFA; thin-cap fibroatheroma, TCFA), the cap thickness and stenosis by diameter were set as variables. In order to establish the correlation between each plaque type and plaque rupture, a numerical simulation was performed and the stress and stress gradient were reviewed to analyze the mechanical behavior...
December 9, 2016: Medical & Biological Engineering & Computing
Luca Liparulo, Zhe Zhang, Massimo Panella, Xudong Gu, Qiang Fang
Clinical assessment plays a major role in post-stroke rehabilitation programs for evaluating impairment level and tracking recovery progress. Conventionally, this process is manually performed by clinicians using chart-based ordinal scales which can be both subjective and inefficient. In this paper, a novel approach based on fuzzy logic is proposed which automatically evaluates stroke patients' impairment level using single-channel surface electromyography (sEMG) signals and generates objective classification results based on the widely used Brunnstrom stages of recovery...
December 1, 2016: Medical & Biological Engineering & Computing
Matthijs J M Cluitmans, Michael Clerx, Nele Vandersickel, Ralf L M Peeters, Paul G A Volders, Ronald L Westra
The inverse problem of electrocardiography aims at noninvasively reconstructing electrical activity of the heart from recorded body-surface electrocardiograms. A crucial step is regularization, which deals with ill-posedness of the problem by imposing constraints on the possible solutions. We developed a regularization method that includes electrophysiological input. Body-surface potentials are recorded and a computed tomography scan is performed to obtain the torso-heart geometry. Propagating waveforms originating from several positions at the heart are simulated and used to generate a set of basis vectors representing spatial distributions of potentials on the heart surface...
November 21, 2016: Medical & Biological Engineering & Computing
Niccolò Mora, Ilaria De Munari, Paolo Ciampolini, José Del R Millán
Brain-Computer Interfaces (BCI) rely on the interpretation of brain activity to provide people with disabilities with an alternative/augmentative interaction path. In light of this, BCI could be considered as enabling technology in many fields, including Active and Assisted Living (AAL) systems control. Interaction barriers could be removed indeed, enabling user with severe motor impairments to gain control over a wide range of AAL features. In this paper, a cost-effective BCI solution, targeted (but not limited) to AAL system control is presented...
November 17, 2016: Medical & Biological Engineering & Computing
Yan Mi, Shaoqin Rui, Chengxiang Li, Chenguo Yao, Jin Xu, Changhao Bian, Xuefeng Tang
High-frequency nanosecond-pulsed electric fields were recently introduced for tumor or abnormal tissue ablation to solve some problems of conventional electroporation. However, it is necessary to study the thermal effects of high-field-intensity nanosecond pulses inside tissues. The multi-parametric analysis performed here is based on a finite element model of liver tissue with a tumor that has been punctured by a pair of needle electrodes. The pulse voltage used in this study ranges from 1 to 4 kV, the pulse width ranges from 50 to 500 ns, and the repetition frequency is between 100 kHz and 1 MHz...
November 16, 2016: Medical & Biological Engineering & Computing
John Albinsson, Åsa Rydén Ahlgren, Tomas Jansson, Magnus Cinthio
Parabolic sub-sample interpolation for 2D block-matching motion estimation is computationally efficient. However, it is well known that the parabolic interpolation gives a biased motion estimate for displacements greater than |y.2| samples (y = 0, 1, …). Grid slope sub-sample interpolation is less biased, but it shows large variability for displacements close to y.0. We therefore propose to combine these sub-sample methods into one method (GS15PI) using a threshold to determine when to use which method...
November 11, 2016: Medical & Biological Engineering & Computing
Azira Khalil, Amir Faisal, Khin Wee Lai, Siew Cheok Ng, Yih Miin Liew
This study proposed a registration framework to fuse 2D echocardiography images of the aortic valve with preoperative cardiac CT volume. The registration facilitates the fusion of CT and echocardiography to aid the diagnosis of aortic valve diseases and provide surgical guidance during transcatheter aortic valve replacement and implantation. The image registration framework consists of two major steps: temporal synchronization and spatial registration. Temporal synchronization allows time stamping of echocardiography time series data to identify frames that are at similar cardiac phase as the CT volume...
November 9, 2016: Medical & Biological Engineering & Computing
Gokce Hale Hatay, Muhammed Yildirim, Esin Ozturk-Isik
The purpose of this study was to apply compressed sensing method for accelerated phosphorus MR spectroscopic imaging ((31)P-MRSI) of human brain in vivo at 3T. Fast (31)P-MRSI data of five volunteers were acquired on a 3T clinical MR scanner using pulse-acquire sequence with a pseudorandom undersampling pattern for a data reduction factor of 5.33 and were reconstructed using compressed sensing. Additionally, simulated (31)P-MRSI human brain tumor datasets were created to analyze the effects of k-space sampling pattern, data matrix size, regularization parameters of the reconstruction, and noise on the compressed sensing accelerated (31)P-MRSI data...
November 8, 2016: Medical & Biological Engineering & Computing
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