Bio-Medical Materials and Engineering - Volume 26, issue s1

Authors: Li, Fan | Li, Dongxu | Wang, Chunhui | Chen, Shanguang | Lv, Ming | Wang, Miao

Article Type: Research Article

Abstract: This paper explores the application of multifractal detrended fluctuation analysis (MF-DFA) on the nonlinear characteristics of correlation between operation force and surface electromyography (sEMG), which is an applied frontier of human neuromuscular system activity. We established cross-correlation functions between the signal of force and four typical sEMG time-frequency domain index sequences (force-sEMG cross-correlation sequences), and dealt with the sequences with MF-DFA. In addition, we demonstrated that the force-sEMG cross-correlation sequences have strong statistical self-similarity and the fractal characteristic of the signal spectrum is similar to 1/f noise or fractional Brownian motion.

Keywords: MF-DFA, operation force signal, sEMG, cross-correlation function

DOI: 10.3233/BME-151412

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1157-S1168, 2015

Authors: Zheng, Wenbin | Ma, Chunlin | Kong, Lingmei | Chen, Xiran | Fan, Wenyao

Article Type: Research Article

Abstract: This study investigated the correlation between AQP4 expression and DTI in rat brainstems after diffuse axonal injuries (DAI). Forty rats were imaged before injury and reimaged at 3, 6, 12, 24 and 72 h post-injury. A control group of 8 rats was imaged and sacrificed for histology but not injured. After brain injury, AQP4 expression and ADC values in the brainstems increased gradually, reaching peak values at 24 h and 12 h, respectively. FA values decreased within 72 h. There was a negative correlation between ADC values and brainstem AQP4 expression at 12 h, and a positive correlation at 24 …h or 72 h ( P < 0.01 ), respectively. Changes in the ADC and FA values in the brainstems indicated brain edema and severe axonal injuries. The correlations between AQP4 expression and time-dependent ADC values aid in understanding brain edema development after DAI. Show more

Keywords: Diffusion axonal injury, brain edema, AQP4, diffusion tensor imaging, apparent diffusion coefficient (ADC), fractional anisotropy (FA)

DOI: 10.3233/BME-151413

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1169-S1175, 2015

Authors: Zhang, Shunqi | Zhou, Xiaoqing | Ma, Ren | Yin, Tao | Liu, Zhipeng

Article Type: Research Article

Abstract: Methods based on the magnetic-acoustic effect are of great significance in studying the electrical imaging properties of biological tissues and currents. The continuous wave method, which is commonly used, can only detect the current amplitude without the sound source position. Although the pulse mode adopted in magneto-acoustic imaging can locate the sonic source, the low measuring accuracy and low SNR has limited its application. In this study, a vector method was used to solve and analyze the magnetic-acoustic signal based on the continuous sine wave mode. This study includes theory modeling of the vector method, simulations to the line model, …and experiments with wire samples to analyze magneto-acoustic (MA) signal characteristics. The results showed that the amplitude and phase of the MA signal contained the location information of the sonic source. The amplitude and phase obeyed the vector theory in the complex plane. This study sets a foundation for a new technique to locate sonic sources for biomedical imaging of tissue conductivity. It also aids in studying biological current detecting and reconstruction based on the magneto-acoustic effect. Show more

Keywords: Magneto-acoustic effect, vector method, sonic source locating, amplitude, phase

DOI: 10.3233/BME-151414

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1177-S1184, 2015

Authors: Xia, Maogeng | Song, Sutao | Yao, Li | Long, Zhiying

Article Type: Research Article

Abstract: Decoding brain states from response patterns with multivariate pattern recognition techniques is a popular method for detecting multivoxel patterns of brain activation. These patterns are informative with respect to a subject’s perceptual or cognitive states. Linear discriminant analysis (LDA) cannot be directly applied to fMRI data analysis because of the “few samples and large features” nature of functional magnetic resonance imaging (fMRI) data. Although several improved LDA methods have been used in fMRI-based decoding, little is known regarding the relative performance of different LDA classifiers on fMRI data. In this study, we compared five LDA classifiers using both simulated data …with varied noise levels and real fMRI data. The compared LDA classifiers include LDA combined with PCA (LDA-PCA), LDA with three types of regularizations (identity matrix, diagonal matrix and scaled identity matrix) and LDA with optimal-shrinkage covariance estimator using Ledoit and Wolf lemma (LDA-LW). The results indicated that LDA-LW was the most robust to noises. Moreover, LDA-LW and LDA with scaled identity matrix showed better stability and classification accuracy than the other methods. LDA-LW demonstrated the best overall performance. Show more

Keywords: LDA, classification, fMRI, decoding, regularized

DOI: 10.3233/BME-151415

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1185-S1192, 2015

Authors: Jeong, Jin-hyoung | Park, Eun-jeong | Cho, Chang-ok | Kim, Yoon-jeong | Lee, Sang-sik

Article Type: Research Article

Abstract: In this study, the radiation generated in the diagnosis of scoliosis, to solve the problems by using an infrared camera and an optical marker system that can diagnose scoliosis developed. System developed by the infrared camera attached to the optical spinal curvature is recognized as a marker to shoot the angle between the two optical markers are measured. Measurement of angle, we used the Cobb’s Angle method used in the diagnosis of spinal scoliosis. We developed a software to be able to output to the screen using an infrared camera to diagnose spinal scoliosis. Software is composed of camera output …unit was manufactured in Labview, angle measurement unit, in Cobb’s Angle measurement unit. In the future, kyphosis, Hallux Valgus, such as the diagnosis of orthopedic disorders that require the use of a diagnostic system is expected case. Show more

Keywords: Scoliosis, optical marker, Cobb’s angle, infrared camera, spine

DOI: 10.3233/BME-151416

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1193-S1199, 2015

Authors: Liu, Yadong | Huang, Liangming | Li, Ming | Zhou, Zongtan | Hu, Dewen

Article Type: Research Article

Abstract: In this work, abundant anticorrelated networks were successfully detected in rest-stating fMRI-BOLD data from 20 subjects. Spatial independent component analysis (sICA) method was applied at both individual and group levels. At the individual level, for each subject, 30 independent components (IC) were estimated, and each IC was transformed using Z-score mapping. The voxels with >5 and < -5 Z-score were denoted as positive signals (PS) and negative signals (NS) respectively. The correlation coefficients between the mean time series of the PS and NS voxels were computed; if the calculated coefficients were <-0.3, the PS and NS voxels were considered to …form an anticorrelated PS-NS network. It was found that 36.5% of the ICs contained an anticorrelated PS-NS network. The spatiotemporal patterns of most PS-NS networks varied from subject to subject, but three networks displaying spatial patterns were comparably consistent among different subjects. For group-level analysis, no anticorrelated PS-NS networks were detected. Our results suggest that future investigations adopt a broader approach for negative BOLD signal characterization. Combined consideration of PS and NS systems help to better elucidate hemodynamic and neuronal brain behavior and further develop understanding of neural mechanisms of brain information processing. Show more

Keywords: Negative BOLD signal, resting-state network, anticorrelated network, low frequency fluctuation

DOI: 10.3233/BME-151417

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1201-S1211, 2015

Authors: Demir, Önder | Yılmaz Çamurcu, Ali

Article Type: Research Article

Abstract: In this study, a computer-aided detection (CAD) system was developed for the detection of lung nodules in computed tomography images. The CAD system consists of four phases, including two-dimensional and three-dimensional preprocessing phases. In the feature extraction phase, four different groups of features are extracted from volume of interests: morphological features, statistical and histogram features, statistical and histogram features of outer surface, and texture features of outer surface. The support vector machine algorithm is optimized using particle swarm optimization for classification. The CAD system provides 97.37% sensitivity, 86.38% selectivity, 88.97% accuracy and 2.7 false positive per scan using three groups …of classification features. After the inclusion of outer surface texture features, classification results of the CAD system reaches 98.03% sensitivity, 87.71% selectivity, 90.12% accuracy and 2.45 false positive per scan. Experimental results demonstrate that outer surface texture features of nodule candidates are useful to increase sensitivity and decrease the number of false positives in the detection of lung nodules in computed tomography images. Show more

Keywords: Lung nodule detection, CAD systems, texture features, medical image processing, classification

DOI: 10.3233/BME-151418

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1213-S1222, 2015

Authors: Shin, Dong-ho | Yang, Yoonseok | Song, Chul-Gyu

Article Type: Research Article

Abstract: Here we developed a real-time photoacoustic tomography (PAT) imaging acquisition device based on the linear array transducer utilized on ultrasonic devices. Also, we produced a phantom including diverse contrast media and acquired PAT imaging as the light source wavelength was changing to see if the contrast media reacted. Indocyanine green showed the highest reaction around the 800-nm band, methylene blue demonstrated the same in the 750-nm band, and gold nanoparticle showed the same in the 700-nm band. However, in the case of superparamagnetic iron oxide, we observed not reaction within the wavelength bands used herein to obtain imaging. Moreover, we …applied selective filtering to the acquired PAT imaging to remove noise from around and reinforce the object’s area. Consequentially, we could see the object area in the imaging was effectively detected and the image noise was removed. Show more

Keywords: Photoacoustic image, real-time, back projection algorithm, ultrasonic imaging, selective filtering

DOI: 10.3233/BME-151419

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1223-S1230, 2015

Authors: Zou, Hua | Zhang, Wen | Wang, Qian

Article Type: Research Article

Abstract: To improve the speed and accuracy of cerebral vessel extraction, a fast and robust method is proposed in this paper. First, volume data are divided into sub-volumes by using octree, and at the same time invalid volume data are eliminated. Second, fuzzy connectedness is introduced to achieve fast cerebral vessel segmentation from 3D MRA Images. The values of gradient and Laplacian transformation are then calculated to improve the accuracy of the distance field. Last, the center of gravity is utilized to refine the initial centerline to make it closer to the actual centerline of the vessel cavity. The experiment demonstrates …that the proposed method can effectively improve the speed and precision of centerline extraction. Show more

Keywords: Segmentation, cerebrovascular, fuzzy connectedness, image segmentation, centerline extraction

DOI: 10.3233/BME-151420

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1231-S1240, 2015

Authors: Sun, Minglei | Yang, Shaobao | Jiang, Jinling | Wang, Qiwei

Article Type: Research Article

Abstract: Pelger-Huet anomaly (PHA) and Pseudo Pelger-Huet anomaly (PPHA) are neutrophil with abnormal morphology. They have the bilobed or unilobed nucleus and excessive clumping chromatin. Currently, detection of this kind of cell mainly depends on the manual microscopic examination by a clinician, thus, the quality of detection is limited by the efficiency and a certain subjective consciousness of the clinician. In this paper, a detection method for PHA and PPHA is proposed based on karyomorphism and chromatin distribution features. Firstly, the skeleton of the nucleus is extracted using an augmented Fast Marching Method (AFMM) and width distribution is obtained through distance …transform. Then, caryoplastin in the nucleus is extracted based on Speeded Up Robust Features (SURF) and a K-nearest-neighbor (KNN) classifier is constructed to analyze the features. Experiment shows that the sensitivity and specificity of this method achieved 87.5% and 83.33%, which means that the detection accuracy of PHA is acceptable. Meanwhile, the detection method should be helpful to the automatic morphological classification of blood cells. Show more

Keywords: Pelger-Huet anomaly, fast marching method, SURF

DOI: 10.3233/BME-151421

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1241-S1248, 2015