bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast axial and lateral displacement estimation in myocardial elastography based on RF signals with predictions
Authors: Zhang Yaonan , Sun Tingting , Teng Yueyang , Li Hong , Kang Yan 
Published: August 2015

Abstract Myocardial elastography (ME) is a strain imaging technique used to diagnose myocardial diseases. Axial and lateral displacement calculations are pre-conditions of strain image acquisition in ME. W.N. Lee et al. proposed a normalized cross-correlation (NCC) and recorrelation method to obtain both axial and lateral displacements in ME. However, this method is not noise-resistant and of high computational cost. This paper proposes a predicted fast NCC algorithm based on W.N. Lee’s method, with the additions of sum-table NCC and a displacement prediction algorithm, to obtain efficient and accurate axial and lateral displacements. Compared to experiments based on the NCC and recorrelation methods, the results indicate that the proposed NCC method is much faster (predicted fast NCC method, 69.75s for a 520×260 image; NCC and recorrelation method, 1092.25s for a 520×260 image) and demonstrates better performance in eliminating decorrelation noise (SNR of the axial and lateral strain using the proposed method, 5.87 and 1.25, respectively; SNR of the axial and lateral strain using the NCC and recorrelation method, 1.48 and 1.09, respectively).
Scattered radiation doses absorbed by technicians at different distances from X-ray exposure: Experiments on prosthesis
Authors: Chiang Hsien-Wen , Liu Ya-Ling , Chen Tou-Rong , Chen Chun-Lon , Chiang Hsien-Jen , Chao Shin-Yu 
Published: August 2015

Abstract This work aimed to investigate the spatial distribution of scattered radiation doses induced by exposure to the portable X-ray, the C-arm machine, and to simulate the radiologist without a shield of lead clothing, radiation doses absorbed by medical staff at 2 m from the central exposure point. Material and method: With the adoption of the Rando Phantom, several frequently X-rayed body parts were exposed to X-ray radiation, and the scattered radiation doses were measured by ionization chamber dosimeters at various angles from the patient. Assuming that the central point of the X-ray was located at the belly button, five detection points were distributed in the operation room at 1 m above the ground and 1-2 m from the central point horizontally. Results: The radiation dose measured at point B was the lowest, and the scattered radiation dose absorbed by the prosthesis from the X-ray’s vertical projection was 0.07 ±0.03 μGy, which was less than the background radiation levels. The Fluke biomedical model 660-5DE (400 cc) and 660-3DE (4 cc) ion chambers were used to detect air dose at a distance of approximately two meters from the central point. The AP projection radiation doses at point B was the lowest (0.07±0.03 μGy) and the radiation doses at point D was the highest (0.26±0.08 μGy) .Only taking the vertical projection into account, the radiation doses at point B was the lowest (0.52 μGy), and the radiation doses at point E was the highest (4 μGy).The PA projection radiation at point B was the lowest (0.36 μGy) and the radiation doses at point E was the highest(2.77 μGy), occupying 10-32% of the maximum doses. The maximum dose in five directions was nine times to the minimum dose. When the PX and the C-arm machine were used, the radiation doses at a distance of 2 m were attenuated to the background radiation level. The radiologist without a lead shield should stand at point B of patient’s feet. Accordingly, teaching materials on radiation safety for radiological interns and clinical technicians were formulated.
Optimization of the imaging quality of 64-slice CT acquisition protocol using Taguchi analysis: A phantom study
Authors: Pan Lung Fa , Erdene Erdenetsetseg , Chen Chun Chi , Pan Lung Kwang 
Published: August 2015

Abstract In this study, the phantom imaging quality of 64-slice CT acquisition protocol was quantitatively evaluated using Taguchi. The phantom acrylic line group was designed and assembled with multiple layers of solid water plate in order to imitate the adult abdomen, and scanned with Philips brilliance CT in order to simulate a clinical examination. According to the Taguchi L8(27) orthogonal array, four major factors of the acquisition protocol were optimized, including (A) CT slice thickness, (B) the image reconstruction filter type, (C) the spiral CT pitch, and (D) the matrix size. The reconstructed line group phantom image was counted by four radiologists for three discrete rounds in order to obtain the averages and standard deviations of the line counts and the corresponding signal to noise ratios (S/N). The quantified S/N values were analyzed and the optimal combination of the four factor settings was determined to be comprised of (A) a 1-mm thickness, (B) a sharp filter type, (C) a 1.172 spiral CT pitch, and (D) a 1024×1024 matrix size. The dominant factors included the (A) filter type and the cross interaction between the filter type and CT slice thickness (A×B). The minor factors were determined to be (C) the spiral CT pitch and (D) the matrix size since neither was capable of yielding a 95% confidence level in the ANOVA test.
Variation of patient imaging doses with scanning parameters for linac-integrated kilovoltage cone beam CT
Authors: Liao Xiongfei , Wang Yunlai , Lang Jinyi , Wang Pei , Li Jie , Ge Ruigang , Yang Jack 
Published: August 2015

Abstract To evaluate the Elekta kilovoltage CBCT doses and the associated technical protocols with patient dosimetry estimation. Image guidance technique with cone-beam CT (CBCT) in radiation oncology on a daily basis can deliver a significant dose to the patient. To evaluate the patient dose from LINAC-integrated kV cone beam CT imaging in image-guided radiotherapy. CT dose index (CTDI) were measured with PTW TM30009 CT ion chamber in air, in head phantom and body phantom, respectively; with different combinations of tube voltage, current, exposure time per frame, collimator and gantry rotation range. Dose length products (DLP) were subsequently calculated to account for volume integration effects. The CTDI and DLP were also compared to AcQSim™ simulator CT for routine clinical protocols. Both CTDIair and CTDIw depended quadratically on the voltage, while linearly on milliampere x seconds (mAs) settings. It was shown that CTDIw and DLP had very close relationship with the collimator settings and the gantry rotation ranges. Normalized CTDIw for Elekta XVI™ CBCT was lower than that of ACQSim simulator CT owing to its pulsed radiation output characteristics. CTDIw can be used to assess the patient dose in CBCT due to its simplicity for measurement and reproducibility. Regular measurement should be performed in QA & QC program. Optimal image parameters should be chosen to reduce patient dose during CBCT.
Evaluation of 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography in rat models with hepatocellular carcinoma with liver cirrhosis
Authors: Park S.I. , Lee J.H. , Ham H.J. , Jung Y.J. , Park M.S. , Lee J. , Maeng L.S. , Chung Y.A. , Jang K.S. 
Published: August 2015

Abstract Liver cirrhosis is a predominant risk factor for hepatocellular carcinoma (HCC). However, the exact mechanism of the progression from cirrhosis to cancer remains unclear. The uptake of 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) is widely used as a marker of increased glucose metabolism to monitor the progression of cancer with positron emission tomography (PET)/computed tomography (CT). Here we investigated the feasibility of using 18F-FDG PET/CT in the diethylnitrosamine (DEN) mediated experimental hepatocellular carcinoma model. Rats received weekly intraperitoneal injections of DEN for 16 weeks for induction of HCC. We recorded starting from 0 days or 0 weeks after the last DEN injection. The weight and survival rate of rats were then measured. Also, an 18F-FDG PET scan and serum analysis were performed at minus 2, 0, plus 2, and plus 4 weeks after the last DEN injection. The body weight of rats was maintained between 350 g and 370 g during 14 and 20 weeks, and the rats were euthanized at 35 days after the last DEN injection. The serum levels of alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphate (ALP) were significantly higher at zero weeks after the last DEN injection. The 18F-FDG uptake for the quantitative evaluation of HCC was done by measuring the region of interest (ROI). At minus two weeks after the last DEN injection, the ROI of rats had significantly increased compared to the normal group, in a time-dependent manner. These results suggest that FDG uptake serves as a good screening test to evaluate the feasibility of DEN-induced HCC.
In vivo evaluating skin doses for lung cancer patients undergoing volumetric modulated arc therapy treatment
Authors: Tseng Hsien-Chun , Pan Lung-Kang , Chen Hsin-Yu , Liu Wen-Shan , Hsu Chang-Chieh , Chen Chien-Yi 
Published: August 2015

Abstract This study is the first to use 10- to 90-kg tissue-equivalent phantoms as patient surrogates to measure peripheral skin doses (Dskin) in lung cancer treatment through Volumetric Modulated Arc Therapy of the Axesse linac. Five tissue-equivalent and Rando phantoms were used to simulate lung cancer patients using the thermoluminescent dosimetry (TLD-100H) approach. TLD-100H was calibrated using 6 MV photons coming from the Axesse linac. Then it was inserted into phantom positions that closely corresponded with the position of the represented organs and tissues. TLDs were measured using the Harshaw 3500 TLD reader. The ICRP 60 evaluated the mean Dskin to the lung cancer for 1 fraction (7 Gy) undergoing VMAT. The Dskin of these phantoms ranged from 0.51±0.08 (10-kg) to 0.22±0.03 (90-kg) mSv/Gy. Each experiment examined the relationship between the Dskin and the distance from the treatment field. These revealed strong variations in positions close to the tumor center. The correlation between Dskin and body weight was Dskin (mSv) = -0.0034x + 0.5296, where x was phantom’s weight in kg. R2 is equal to 0.9788. This equation can be used to derive an equation for lung cancer in males. Finally, the results are compared to other published research. These findings are pertinent to patients, physicians, radiologists, and the public.
A CT reconstruction approach from sparse projection with adaptive-weighted diagonal total-variation in biomedical application
Authors: Deng Luzhen , Mi Deling , He Peng , Feng Peng , Yu Pengwei , Chen Mianyi , Li Zhichao , Wang Jian , Wei Biao 
Published: August 2015

Abstract For lack of directivity in Total Variation (TV) which only uses x-coordinate and y-coordinate gradient transform as its sparse representation approach during the iteration process, this paper brought in Adaptive-weighted Diagonal Total Variation (AwDTV) that uses the diagonal direction gradient to constraint reconstructed image and adds associated weights which are expressed as an exponential function and can be adaptively adjusted by the local image-intensity diagonal gradient for the purpose of preserving the edge details, then using the steepest descent method to solve the optimization problem. Finally, we did two sets of numerical simulation and the results show that the proposed algorithm can reconstruct high-quality CT images from few-views projection, which has lower Root Mean Square Error (RMSE) and higher Universal Quality Index (UQI) than Algebraic Reconstruction Technique (ART) and TV-based reconstruction method.
Biological impedance cross evaluation and imaging from composite measurements of magnetic and electrical methods
Authors: Ran Peng , Xiao Xiaoming , He Wei , Li Zhangyong 
Published: August 2015

Abstract Because of the need for rapid detection and location of diseases in clinical applications, this work proposes a composite measurement of magnetic induction tomography (MIT) and electrical impedance tomography (EIT). This paper is composed of the following aspects: portable and integral hardware design, stable dual constant-current sources, the composite detection method, cross-plane data acquirement, 3-dimensional image reconstruction and so on. A qualitative evaluation of conductivity, resolution and relative position error were taken by combining the EIT and MIT methods via the experiment model. The sensitivities of both methods were analyzed to improve the imaging results. The reconstruction results reveal that the system is capable of obtaining better physiological measurements, which is very useful in clinical monitoring, quick medical diagnosing and preliminary screening of community health.
Sleep apnea classification based on respiration signals by using ensemble methods
Authors: Avcı Cafer , Akbaş Ahmet 
Published: August 2015

Abstract In this study, an efficient and robust method classifying the minute based occurrence of sleep apnea is aimed. Three respiration signals obtained from abdominal, chest and nasal way extracted from polysomnography recordings. Wavelet transform based on feature extraction methods are applied on the 1 minute length respiration signals. Dimension reduction process is facilitated by using principal component analysis. The features obtained from 8 recordings are used for the classification sleep apnea by using three ensemble classifiers. According to the results, the classification accuracies have been obtained between 92.07-98.43%, 92.75-98.68% and 92.42-98.61% by using three different ensemble classifier based on abdominal, chest and nasal based analysis, respectively for AdaBoost, Random Forest and Random Subspace. However the best result is obtained analyzing nasal based respiratory signal by using Random Forest method. In this case accuracy is 98.68%.
Application of an evolutionary algorithm in the optimal design of micro-sensor
Authors: Lu Qibing , Wang Pan , Guo Sihai , Sheng Buyun , Liu Xingxing , Fan Zhun 
Published: August 2015

Abstract This paper introduces an automatic bond graph design method based on genetic programming for the evolutionary design of micro-resonator. First, the system-level behavioral model is discussed, which based on genetic programming and bond graph. Then, the geometry parameters of components are automatically optimized, by using the genetic algorithm with constraints. To illustrate this approach, a typical device micro-resonator is designed as an example in biomedicine. This paper provides a new idea for the automatic optimization design of biomedical sensors by evolutionary calculation.
A portable wireless power transmission system for video capsule endoscopes
Authors: Shi Yu , Yan Guozheng , Zhu Bingquan , Liu Gang 
Published: August 2015

Abstract Wireless power transmission (WPT) technology can solve the energy shortage problem of the video capsule endoscope (VCE) powered by button batteries, but the fixed platform limited its clinical application. This paper presents a portable WPT system for VCE. Besides portability, power transfer efficiency and stability are considered as the main indexes of optimization design of the system, which consists of the transmitting coil structure, portable control box, operating frequency, magnetic core and winding of receiving coil. Upon the above principles, the correlation parameters are measured, compared and chosen. Finally, through experiments on the platform, the methods are tested and evaluated. In the gastrointestinal tract of small pig, the VCE is supplied with sufficient energy by the WPT system, and the energy conversion efficiency is 2.8%. The video obtained is clear with a resolution of 320×240 and a frame rate of 30 frames per second. The experiments verify the feasibility of design scheme, and further improvement direction is discussed.
Wireless charing pillow for a fully implantable hearing aid: Design of a circular array coil based on finite element analysis for reducing magnetic weak zones
Authors: Lim Hyung-Gyu , Kim Jong Hoon , Shin Dong Ho , Woo Seong Tak , Seong Ki Woong , Lee Jyung Hyun , Kim Myoung Nam , Wei Qun , Cho Jin-Ho 
Published: August 2015

Abstract Many types of fully implantable hearing aids have been developed. Most of these devices are implanted behind the ear. To maintain the implanted device for a long period of time, a rechargeable battery and wireless power transmission are used. Because inductive coupling is the most renowned method for wireless power transmission, many types of fully implantable hearing aids are transcutaneously powered using inductively coupled coils. Some patients with an implantable hearing aid require a method for conveniently charging their hearing aid while they are resting or sleeping. To address this need, a wireless charging pillow has been developed that employs a circular array coil as one of its primary parts. In this device, all primary coils are simultaneously driven to maintain an effective charging area regardless of head motion. In this case, however, there may be a magnetic weak zone that cannot be charged at the specific secondary coil’s location on the array coil. In this study, assuming that a maximum charging distance is 4 cm, a circular array coil—serving as a primary part of the charging pillow—was designed using finite element analysis. Based on experimental results, the proposed device can charge an implantable hearing aid without a magnetic weak zone within 4 cm of the perpendicular distance between the primary and secondary coils.
Sleep snoring detection using multi-layer neural networks
Authors: Nguyen Tan Loc , Won Yonggwan 
Published: August 2015

Abstract Snoring detection is important for diagnosing obstructive sleep apnea syndrome (OSAS) and other respiratory sleep disorders. In general, audio signal processing such as snoring sound analysis uses the frequency characteristics of the signal. Recently, a correlational filter Multilayer Perceptron neural network (f-MLP) has been proposed, which has the first hidden layer of correlational filter operations in frequency domain. It demonstrated a superior classification performance for the pattern sets; of these, frequency information is the dominant feature for classification. The first hidden layer is implemented with the correlational filter operation; its output is the power spectrum of the filter output, while the other layers are the same as the ordinary multilayer Perceptron (o-MLP). By using the back-propagation learning algorithm for the correlational filter layer, f-MLP was able to self-adapt the filter coefficients to produce its output with more discrimination power for classification in the higher layer. In this research, this f-MLP was applied for sleep snoring signal detection. As a result, the f-MLP achieved an average detection rate of 96% for the test patterns, compared to the conventional multilayer neural network that demonstrates an 82% average detection rate.
A method of extracting disease-related microRNAs through the propagation algorithm using the environmental factor based global miRNA network
Authors: Ha Jihwan , Kim Hyunjin , Yoon Youngmi , Park Sanghyun 
Published: August 2015

Abstract MicroRNAs (miRNA) are known to be involved in the development of various diseases. Hence various scientists in the field have been utilized computational analyses to determine the relationship between miRNA and diseases. However, the knowledge of miRNA and disease is still very limited. Therefore, we combined Environmental Factor (EF) data to a miRNA global network. Increasing research has shown that relationship between miRNAs and EFs play a significant role in classifying types of diseases. Environmental Factors consist of radiation, drugs, viruses, alcohol, cigarettes, and stress. Our global network considered all the interactions between every pair of miRNAs, which has led to precise analyses in comparison to local networks. As a result, our approaches’ performance demonstrated its effectiveness in identifying disease-related miRNA and this is the area under the ROC curve (AUC) of 74.46%. Furthermore, comparative experiment has shown that our approach performs comparable to other existing methods with an accuracy of 94%, 90% and 96% for breast cancer, colonic cancer, and lung cancer respectively. In conclusion, these results support that our research has broadened new biological insights on identifying disease-related miRNAs.
A comparative analysis of multiple sequence alignments for biological data
Authors: Manzoor Umar , Shahid Sarosh , Zafar Bassam 
Published: August 2015

Abstract Multiple sequence alignment plays a key role in the computational analysis of biological data. Different programs are developed to analyze the sequence similarity. This paper highlights the algorithmic techniques of the most popular multiple sequence alignment programs. These programs are then evaluated on the basis of execution time and scalability. The overall performance of these programs is assessed to highlight their strengths and weaknesses with reference to their algorithmic techniques. In terms of overall alignment quality, T-Coffee and Mafft attain the highest average scores, whereas K-align has the minimum computation time.
Faster single-end alignment generation utilizing multi-thread for BWA
Authors: Jo Heeseung , Koh Gunhwan 
Published: August 2015

Abstract Due to next-generation sequencing (NGS) technology, genome sequencing is able to process much more data at low cost. In NGS data analysis, the mapping of sequences into a reference genome takes the largest amount of time to process. Although the Burrows-Wheeler Aligner (BWA) tool is one of the most widely used open-source software tools to align read sequences, it is still limited in that it does not fully support multi-thread mechanisms during the alignment steps. In this paper, we propose a BWA-MT tool, evolved from BWA but supporting multi-thread computation, designed to fully utilize the underlying multi-core architecture of computing resources. By using multi-thread computation, BWA-MT can significantly shorten the time needed to generate an alignment for single-end read sequences. Meanwhile, it generates an identical Sequence Alignment Map (SAM) result file as BWA. To evaluate BWA-MT, we use an evaluation system equipped with twelve cores and 32 GB memory. As a workload, we used the hg19 human genome reference sequence and various numbers of read sequences from 1M to 40M. In our evaluation, BWA-MT displays up to 3.7 times faster performance and generates an identical SAM result file to BWA. Although the increased speed might be dependent on computing resources, we confirm that BWA-MT is highly efficient and effective.
Prediction model of sinoatrial node field potential using high order partial least squares
Authors: Feng Yu , Cao Hui , Zhang Yanbin 
Published: August 2015

Abstract High order partial least squares (HOPLS) is a novel data processing method. It is highly suitable for building prediction model which has tensor input and output. The objective of this study is to build a prediction model of the relationship between sinoatrial node field potential and high glucose using HOPLS. The three sub-signals of the sinoatrial node field potential made up the model’s input. The concentration and the actuation duration of high glucose made up the model’s output. The results showed that on the premise of predicting two dimensional variables, HOPLS had the same predictive ability and a lower dispersion degree compared with partial least squares (PLS).