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

Authors: Choi, Jung-Kyu | Cha, Eun-Jong | Kim, Kyung-Ah | Won, Yonggwan | Kim, Jung-Ja

Article Type: Research Article

Abstract: From a subject group of pes cavus, the purpose of this study was to evaluate the biomechanical characteristics of lower limbs, based on plantar foot pressure and electromyography (EMG) activities, by the effects on two kind of custom-made insoles. Ten individuals among thirty females with a clinical diagnosis of idiopathic pes cavus (mean age (SD): 22.3 (0.08) years) were selected for the study. The plantar foot pressure data and EMG activities of four lower limb muscles were collected, when subjects walked on a treadmill, under three different experimental conditions. The plantar foot pressure data was analyzed, after the bilateral foot …was divided into three areas of masks and into four sections of stance phase, to compare plantar foot pressure. The EMG activities were analyzed for integrated EMG (IEMG) value. The results show that plantar foot pressure concentrated in particular parts is decreased by custom-made insoles. In the case of EMG, all the muscle activities decreased significantly. The custom-made insoles dispersed pressure concentrated by the higher medial longitudinal arch and improved the efficient use of muscles. In particular, the extension structure in the forefoot of custom-made insoles was more efficient for pes cavus. Therefore, it could help patients to walk, by offering support to prevent the disease of pes cavus deformity, and to relieve the burden and fatigue in the lower limbs on gait. Show more

Keywords: Gait, custom-made insole, pes cavus, plantar foot pressure, EMG

DOI: 10.3233/BME-151362

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S705-S715, 2015

Authors: Kang, Ho Chul | Lee, Ju Hwan | Kim, Sung Min

Article Type: Research Article

Abstract: This study analyzes the moment of human main joints (knee and hip) for developing a wearable walking assistant robot. Experiments were performed on two steps to analyze motions. Three healthy males with no neural and musculoskeletal disorders volunteered to participate in this study. In the step up test, the maximum moment was 0.98±0.05 Nm/kg for the knee and 0.52±0.04 Nm/kg for the hip. In the sit-to-stand test, the maximum moment was 0.88±0.06 Nm/kg for the knee and 0.44±0.04 Nm/kg for the hip. The moment of the hip was significantly higher than the knee. In addition, the motion analysis results were …compared with proven validity and inverse dynamics analysis results. Experimental results showed that there was no significant difference in the absolute value or pattern. For the step up motion, after wearing Powered Gait Orthosis (PGO), the hip joint torque value (1.22 Nm/kg) was about 1.3 times greater than the knee joint torque value (0.96 Nm/kg). It indicates that the step up motion requires more power from the hip joint than the knee joint. Moreover, there was a significant torque value difference for before and after wearing the device. Show more

Keywords: Simulation, Powered Gait Orthosis (PGO), torque, joint

DOI: 10.3233/BME-151363

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S717-S727, 2015

Authors: Zhu, Yanhe | Zhang, Guoan | Zhang, Chao | Liu, Gangfeng | Zhao, Jie

Article Type: Research Article

Abstract: This paper introduces novel modern equipment—a lower extremity exoskeleton, which can implement the mutual complement and the interaction between human intelligence and the robot’s mechanical strength. In order to provide a reference for the exoskeleton structure and the drive unit, the human biomechanics were modeled and analyzed by LifeModeler and Adams software to derive each joint kinematic parameter. The control was designed to implement the zero-force interaction between human and exoskeleton. Furthermore, simulations were performed to verify the control and assist effect. In conclusion, the system scheme of lower extremity exoskeleton is demonstrated to be feasible.

Keywords: Lower extremity exoskeleton, controller, zero-force interaction, simulation

DOI: 10.3233/BME-151364

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S729-S738, 2015

Authors: Zhang, Hong | Xiao, Zheng | Lin, Shien-fong

Article Type: Research Article

Abstract: Sino-atrial node cells (SANCs) play a significant role in rhythmic firing. To investigate their role in arrhythmia and interactions with the atrium, computer simulations based on cellular dynamic mathematical models are generally used. However, the large-scale computation usually makes research difficult, given the limited computational power of Central Processing Units (CPUs). In this paper, an accelerating approach with Graphic Processing Units (GPUs) is proposed in a simulation consisting of the SAN tissue and the adjoining atrium. By using the operator splitting method, the computational task was made parallel. Three parallelization strategies were then put forward. The strategy with the shortest …running time was further optimized by considering block size, data transfer and partition. The results showed that for a simulation with 500 SANCs and 30 atrial cells, the execution time taken by the non-optimized program decreased 62% with respect to a serial program running on CPU. The execution time decreased by 80% after the program was optimized. The larger the tissue was, the more significant the acceleration became. The results demonstrated the effectiveness of the proposed GPU-accelerating methods and their promising applications in more complicated biological simulations. Show more

Keywords: Sino-atrial node, atrium, graphic processing units, optimization, computer simulations, dynamic model

DOI: 10.3233/BME-151365

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S739-S746, 2015

Authors: Wang, Dangxiao | Zhao, Siming | Li, Teng | Zhang, Yuru | Wang, Xiaoyan

Article Type: Research Article

Abstract: To evaluate the fidelity of the i Dental system and investigate its utility and performance on simulated drilling operations, user studies consisting of objective and subjective evaluations were performed. A voxel-based drilling simulation sub-system in the i Dental system was employed for evaluation. Twenty participants were enrolled to take part in the experiments and were divided into two groups: novice and resident. A combined evaluation method including objective and subjective methods was employed. The objective evaluation included two dental drilling tasks: caries removal operation and pulp chamber opening operation. In the subjective method, participants were required to complete a questionnaire …to evaluate the fidelity of the system after the operation task. Based on the structured global assessment scales in the questionnaire, the average subjective evaluation scores of the proposed metrics were greater than 4.5, demonstrating that the system operated above medium fidelity. Dentists expressed great interest and positive attitudes toward the potential of the i Dental system. The objective evaluation data including time spent and the volume of removed healthy and carious tissue were obtained. Although no significant differences could be found between the two groups, the volume of removed caries and the depth of pulp chamber insertion manifested small standard deviations. Evaluation results illustrated that dentists were willing to use the virtual reality training system. Several future research topics were identified, including increasing the task difficulty, improving the system fidelity and introducing appropriate finger rest points. Show more

Keywords: Dental simulation, virtual reality, haptic, dental drilling, user evaluation, objective evaluation

DOI: 10.3233/BME-151366

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S747-S756, 2015

Authors: Liu, Yixiang | Zang, Xizhe | Liu, Xinyu | Wang, Lin

Article Type: Research Article

Abstract: High compliant legs are essential for the efficient versatile locomotion and shock absorbency of humans. This study proposes a biped robot actuated by pneumatic artificial muscles to mimic human locomotion. On the basis of the musculoskeletal architecture of human lower limbs, each leg of the biped robot is modeled as a system of three segments, namely, hip joint, knee joint, and ankle joint, and eleven muscles, including both monoarticular and biarticular muscles. Each rotational joint is driven by a pair of antagonistic muscles, enabling joint compliance to be tuned by operating the pressure inside the muscles. Biarticular muscles play an …important role in transferring power between joints. Walking simulations verify that biarticular muscles contribute to joint compliance and can absorb impact energy when the robot makes an impact upon ground contact. Show more

Keywords: Biped robot, compliance, pneumatic artificial muscles, biarticular muscles

DOI: 10.3233/BME-151367

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S757-S766, 2015

Authors: Xu, Qin | Ye, Datian

Article Type: Research Article

Abstract: Auditory temporal integration (ATI) has been widely described in psychoacoustic studies, especially for loudness perception. Loudness increases with increasing sound duration for durations up to a time constant about 100 ~ 200 ms, and then loudness becomes saturated with more duration increase. However, the electrophysiological mechanism underlying the ATI phenomenon has not been well understood. To investigate ATI at the brainstem level of auditory system and its relationship to cortical and behavioral ATI, frequency follow response (FFR) was acquired in our study. Simultaneously, ATI in auditory cortex was evaluated by cortical response P1. Behavioral loudness and electrophysiological measures were estimated …from normal-hearing young adults for vowel /a/ whose durations varied from 50 ms to 175 ms. Significant effects of stimulus duration were found both on FFR and P1 amplitudes. Linear regression analysis revealed that as stimulus duration increased, brainstem FFR amplitude was significantly associated with cortical P1 amplitude and behavioral loudness, which confirmed the existence of temporal integration in auditory brainstem. Moreover, behavioral loudness ATI was better predicted using brainstem and cortical measures together than merely using each one separately, indicating an interplay and coordination for ATI across the three levels along auditory pathway. Show more

Keywords: Auditory temporal integration (ATI), frequency following response (FFR), cortical response P1, loudness

DOI: 10.3233/BME-151368

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S767-S778, 2015

Authors: Chinen, Koyu | Kinjo, Ichiko | Zamami, Aki | Irei, Kotoyo | Nagayama, Kanako

Article Type: Research Article

Abstract: Human body impedance analysis is an effective tool to extract electrical information from tissues in the human body. This paper presents a new measurement method of impedance using armpit electrode and a new equivalent circuit model for the human body. The lowest impedance was measured by using an LCR meter and six electrodes including armpit electrodes. The electrical equivalent circuit model for the cell consists of resistance R and capacitance C. The R represents electrical resistance of the liquid of the inside and outside of the cell, and the C represents high frequency conductance of the cell membrane. We propose …an equivalent circuit model which consists of five parallel high frequency-passing CR circuits. The proposed equivalent circuit represents alpha distribution in the impedance measured at a lower frequency range due to ion current of the outside of the cell, and beta distribution at a high frequency range due to the cell membrane and the liquid inside cell. The calculated values by using the proposed equivalent circuit model were consistent with the measured values for the human body impedance. Show more

Keywords: BIA, human body impedance, equivalent electrical circuit model, armpit electrode

DOI: 10.3233/BME-151369

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S779-S786, 2015

Authors: Sun, Xiang | Kim, Jin Young | Won, Yonggwan | Kim, Jung-Ja | Kim, Kyung-Ah

Article Type: Research Article

Abstract: Snoring, a common symptom in the general population may indicate the presence of obstructive sleep apnea (OSA). In order to detect snoring events in sleep sound recordings, a novel method was proposed in this paper. The proposed method operates by analyzing the acoustic characteristics of the snoring sounds. Based on these acoustic properties, the feature vectors are obtained using the mean and standard deviation of the sub-band spectral energy. A support vector machine is then applied to perform the frame-based classification procedure. This method was demonstrated experimentally to be effective for snoring detection. The database for detection included full-night audio …recordings from four individuals who acknowledged having snoring habits. The performance of the proposed method was evaluated by classifying different events (snoring, breathing and silence) from the sleep sound recordings and comparing the classification against ground truth. The proposed algorithm was able to achieve an accuracy of 99.61% for detecting snoring events, 99.16% for breathing, and 99.55% for silence. Show more

Keywords: Snoring, acoustic analysis, obstructive sleep apnea, sub-band spectra

DOI: 10.3233/BME-151370

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S787-S793, 2015

Authors: Wang, Lan | Li, Hailong | Wang, Zhengyu | Meng, Fandong

Article Type: Research Article

Abstract: During the rehabilitation process, it is essential to accurately judge a patient’s recovery in a timely manner. A reasonable and matched training program is significant in the development of rehabilitation system. This paper presents a new upper limb rehabilitation training system, which consists of an upper limb rehabilitation training device, a current detection circuit, a motor speed test circuit, a surface EMG (sEMG) sensor, and a dSPACE HIL simulation platform. The real-time output torque of the servo motor is calculated by using the motor’s real-time current and speed, in order to monitor the patient’s training situation. The signal of sEMG …is collected in real time and is processed with root mean square (RMS) to characterize the degree of muscle activation. Based on this rehabilitation system, maximum voluntary contraction (MVC) experiments, passive training experiments under different speeds, and active training experiments under different damping are studied. The results show that this new system performs real-time and accurate monitoring of a patient’s training situation. It can also assess a patient’s recovery through muscle activation. To a certain extent, this system provides a platform for research and development of rehabilitation medical engineering. Show more

Keywords: Surface EMG, upper limb rehabilitation system, rehabilitation assessment

DOI: 10.3233/BME-151371

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S795-S801, 2015

Authors: Heo, Jae-Hoon | Kim, Ji-Won | Kwon, Yuri | Lee, Sang-Ki | Eom, Gwang-Moon | Kwon, Do-Young | Lee, Chan-Nyeong | Park, Kun-Woo | Manto, Mario

Article Type: Research Article

Abstract: Essential tremor is an involuntary trembling of body limbs in people without tremor-related disease. In previous study, suppression of tremor by sensory electrical stimulation was confirmed on the index finger. This study investigates the effect of sensory stimulation on multiple segments and joints of the upper limb. It denotes the observation regarding the effect’s continuity after halting the stimulation. 18 patients with essential tremor (8 men and 10 women) participated in this study. The task, “arms stretched forward”, was performed and sensory electrical stimulation was applied on four muscles of the upper limb (Flexor Carpi Radialis, Extensor Carpi Radialis, Biceps …Brachii, and Triceps Brachii) for 15 seconds. Three 3-D gyro sensors were used to measure the angular velocities of segments (finger, hand, and forearm) and joints (metacarpophalangeal and wrist joints) for three phases of pre-stimulation (Pre), during-stimulation (On), and 5 minute post-stimulation (P5). Three characteristic variables of root-mean-squared angular velocity, peak power, and peak power frequency were derived from the vector sum of the sensor signals. At On phase, RMS velocity was reduced from Pre in all segments and joints while peak power was reduced from Pre in all segments and joints except for forearm segment. Sensory stimulation showed no effect on peak power frequency. All variables at P5 were similar to those at On at all segments and joints. The decrease of peak power of the index finger was noted by 90% during stimulation from that of On phase, which was maintained even after 5 min. The results indicate that sensory stimulation may be an effective clinical method to treat the essential tremor. Show more

Keywords: Essential tremor, postural tremor, sensory stimulation, arms stretched forward, gyro sensor

DOI: 10.3233/BME-151372

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S803-S809, 2015

Authors: Aresti-Bartolome, Nuria | Garcia-Zapirain, Begonya

Article Type: Research Article

Abstract: This paper studies and assesses how rehabilitation activities and supervised computer games incorporated into a system aimed at people diagnosed with Autism Spectrum Disorder (ASD) can be used to work on the areas affected by ASD at any time and in any place. This research specifically assesses the areas that affect communication and interaction between people with ASD and professionals. In order to do this, a group of 20 children diagnosed with ASD of between 3 and 8 years old (clinical group) was used, together with a group of 20 children of between 3 and 8 years old with a …neurotypical development, which served as a control group. During the tests, response time and visual interaction with the session leader were evaluated. Despite the fact that the clinical group spent more time (M = 21.08 sec) than the control group (M = 4.52) to interact leader, eye contact predominated in the interaction. As a result of the pilot study, the system obtained could help in cognitive rehabilitation. Show more

Keywords: Eyetracking, rehabilitation, ASD, interaction

DOI: 10.3233/BME-151373

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S811-S824, 2015

Authors: Liu, Yongji | Wang, Zhaoqi | Wang, Yan

Article Type: Research Article

Abstract: To evaluate the ability of assessing the refractive change induced by myopic laser surgery using the intrinsic data, obtained from a reference intrinsic to the cornea. Twenty-nine eyes with laser in situ keratomileusis for myopia were included in the study. Statistical analyses were performed to determine the relationship between refractive changes and two kinds of corneal power: KIP_value (obtained by keratometric index of 1.3375 and radius of curvature) and RIP_value (obtained by real corneal refraction index of 1.376 and radius of curvature). The comparisons were made between results given by intrinsic data and Pentacam HR. Preoperatively, the intrinsic radii of …curvature are significantly less (p≪0.001) than those from Pentacam HR, while the intrinsic radii of curvature are significantly larger (p≪0.001) after surgery. The corneal power changes given by Pentacam HR always underestimate the refractive changes. However, the intrinsic data generally reduce the discrepancies between the corneal power and the refractive changes. The intrinsic KIP_value correlated best with the refractive changes at the corneal plane (p≪0.001) with a prediction error as low as 1.51%. The use of intrinsic data of the cornea can possibly provide an accurate estimation of surgically induced refractive changes. Show more

Keywords: Corneal power changes, refractive changes, intrinsic data

DOI: 10.3233/BME-151374

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S825-S832, 2015

Authors: Kim, Hyun-Jun | Yi, Jeong-Han | Kim, Hyung-Sik | Chung, Soon-Cheol | Baek, Ji-Hye | Lee, Jung-Chul | Park, Sung-Jun | Jeong, Ul-Ho | Gim, Seon-Young | Kim, Sung-Phil | Lim, Dae-Woon | Choi, Mi-Hyun

Article Type: Research Article

Abstract: The change of neuronal activation due to the passive perception of various driving speeds in comparison to a reference driving speed was assessed using functional Magnetic Resonance Imaging. Videos recorded in real driving conditions on the road at driving speeds of 50, 70, 90, and 110 km/h were shown as visual stimuli. An experiment consisted of three blocks, each having a control phase (50km/h) and a stimulation phase (70, 90, or 110 km/h). In the passive perception of various driving speed differences, the areas related to visual cognition and spatial attention such as temporal, occipital, parietal, frontal areas, and cerebellum …were activated. As the driving speed difference increased, the number of activated voxels also increased in the areas related to visual cognition. However, the visual cognition related areas showed a different pattern from the spatial attention related area with an increase of the driving speed difference. This implies that each brain area has a different level of involvement in the passive perception of the driving speed difference, although both visual cognitions related areas and spatial attention related area are related to it. Show more

Keywords: Driving speed difference, passive perception, visual cognition, spatial attention (vigilance)

DOI: 10.3233/BME-151375

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S833-S840, 2015

Authors: Zhu, Wenting | Su, Jing | Liu, Jing | Jiang, Changbin

Article Type: Research Article

Abstract: In this study, it was investigated whether a NO signaling pathway is involved in the anti-epileptic effect of curcumin on pentylenetetrazol (PTZ)-kindled rats. PTZ-kindled rats received different doses of curcumin that were administered intraperitoneally for 24 days. Either a non-selective inhibitor of nitric oxide synthase (NOS) (N-nitro-L-arginine methyl ester (L-NAME)), a selective inhibitor of neuronal NOS (7-Nitroindazole (7-NI)), a selective inhibitor of inducible NOS (aminoguanidine (AG)), or a NO precursor (L-arginine (L-ARG)) was administered chronically to evaluate the role of NO in curcumin’s anti-seizure effect. A chronic administration of curcumin (200 mg/kg) was most effective for decreasing the mean frequency …of epileptiform discharge. Furthermore, a pretreatment with L-NAME or 7-NI augmented the anti-epileptic effect of curcumin. In contrast, AG failed to significantly alter the anti-epileptic effect of curcumin. A pretreatment with L-ARG temporally reversed the anti-epileptic effect of curcumin in the early stage, but in the late stage, it potentiated curcumin’s anti-epileptic effect. These findings suggest that the L-arginine–nitric oxide pathway may be involved in the anti-epileptic properties of curcumin, and that the role of nNOS (and not iNOS) is prominent in this neuroprotective feature. Show more

Keywords: Curcumin, nitric oxide, nitric oxide synthase, epilepsy, pentylenetetrazol

DOI: 10.3233/BME-151376

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S841-S850, 2015

Authors: Pan, Lung Fa | Davaa, Otgonbaatar | Chen, Chien Yi | Pan, Lung Kwang

Article Type: Research Article

Abstract: In this study, the contrast-induced-nephropathy (CIN) of vascular patients who had undergone angiography was quantitatively evaluated using a semi-empirical model. The model compiled six essential serum readings and biological data from 70 patients in order to develop a 1st-order nonlinear equation with 16 defined terms. The expectation value of the model was used to predict the serum creatinine reading of patients that had been determined to be at high risk of CIN after contrast media (CM) administration. The other five variables included body surface area (BSA), administrated CM, serum creatinine level before CM administration, blood urea nitrogen (BUN), and systolic …blood pressure level. A loss function was used to define the difference between the observed and predicted serum creatinine readings after CM administration. The dominant variables were proven to be systolic blood pressure, serum creatinine level before CM administration, and BSA. The cross interaction between the serum creatinine level before CM administration and systolic blood pressure was the decisive term of the model’s performance, indicating that both should be specially considered in order to prevent CIN. The BSA, which was usually ignored by medical staff, was also proven to be a significant variable, whereas the BUN reading and amount of injected contrast media were negligible in the semi-empirical model. Show more

Keywords: CIN, BSA, serum creatinine, robust designation, loss function

DOI: 10.3233/BME-151377

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S851-S860, 2015

Authors: Park, Byung Kyu | Kim, Ji-Won | Kwon, Yuri | Heo, Jae-Hoon | Yoon, Joo-Seok | Eom, Gwang-Moon

Article Type: Research Article

Abstract: Correct-active-repetitive exercise is important for the motor recovery in hemiplegics. The present study hypothesizes that the electromyogram (EMG)-controlled assistance of motion would be an effective implementation of the concept for the rehabilitation of the hemiplegic shoulder, even in chronic patients. This study aims to investigate the feasibility of the suggested method. The motor intention is derived from the EMG of the shoulder muscles and the shoulder movement (flexion and abduction) is assisted by an electro-mechanical system only when the motor intention (EMG amplitude) exceeded the threshold. Twelve patients in the chronic stage of stroke participated in this pilot study. The …EMG-controlled assistive exercise lasts for two weeks, 20 min per day and 5 days a week. The active range of motion in both abduction and flexion increases significantly after the intervention (p < 0.01). The maximum torque increases in both directions, and the increase is significant in the abduction (p < 0.01). The Fugl–Myer motor assessment score is improved greatly in the shoulder-related items (p < 0.01), but neither in the shoulder-unrelated items of the upper extremity (p = 0.13) nor in the lower extremity items (p = 0.19). This pilot study demonstrates that EMG-controlled assistive exercise can improve shoulder motor functions related to selected muscles and the suggested method is promising for the motor recovery of the shoulder in chronic hemiplegia. Show more

Keywords: EMG-control, assistive exercise, hemiplegia, shoulder, motor recovery

DOI: 10.3233/BME-151378

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S861-S869, 2015

Authors: Xiao, Xu | Wanyan, Xiaoru | Zhuang, Damin

Article Type: Research Article

Abstract: Mental workload is an important component in complex human-machine systems. The limited applicability of empirical workload measures produces the need for workload modeling and prediction methods. In the present study, a mental workload prediction model is built on the basis of attentional resource allocation and information processing to ensure pilots’ accuracy and speed in understanding large amounts of flight information on the cockpit display interface. Validation with an empirical study of an abnormal attitude recovery task showed that this model’s prediction of mental workload highly correlated with experimental results. This mental workload prediction model provides a new tool for optimizing …human factors interface design and reducing human errors. Show more

Keywords: Mental workload, prediction model, attention allocation, information theory, ergonomics

DOI: 10.3233/BME-151379

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S871-S879, 2015

Authors: Feng, Yu | Cao, Hui | Wang, Yanxia | Zhang, Yanbin

Article Type: Research Article

Abstract: The objective of this study is to build a fuzzy linguistic prediction model (FLPM) for analyzing the actuation duration of acute hyperglycemia to sinoatrial node field potential. The field potential was recorded using microelectrode arrays (MEA). The experimental data were analyzed using partial least squares (PLS), support vector machine (SVM), back propagation neural network (BPNN) and the proposed method. The experimental results showed that the fuzzy linguistic prediction model could be adopted for predicting the actuation duration of high glucose to the sinoatrial node field potential. Compared with the other aforementioned models, the proposed model had higher prediction accuracy.

Keywords: Sinoatrial node field potential, acute hyperglycemia, linguistic prediction model, fuzzy rule

DOI: 10.3233/BME-151380

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S881-S887, 2015

Authors: Lu, Yang | Wang, Qi | Zhang, Song | Yang, Lin | Liang, Liyan | Cui, Jingxuan

Article Type: Research Article

Abstract: In this paper, participants operated visual display terminals (VDT); the authors analyzed their pulse wave signals to develop objective indices for diagnosing and assessing VDT-induced. The experiment used 30 healthy undergraduates test subjects; each subject operated static PC for 4 hours. The pulse waves of local blood volumes in the test subjects’ finger-tips were measured every 30 minutes for 2 minutes. After the experiment, the pulse wave parameters were analyzed. All test subjects exhibited signs of visual fatigue according to the fatigue scale results. There were significant differences of heart rate (HR), which clearly declined before and after the experiment …(P<0.01). The indexes RMSSD, SDNN, P3, P4, P5, P6, and TP had significant differences (P<0.01) and all rose. The positions of the main and dicrotic waves advanced (P<0.01). The experiment parameters prompted significant changes; pulse wave forms changed during VDT work. Based on these results, pulse wave analysis holds promise as an effective, noninvasive technique for measuring VDT fatigue. Show more

Keywords: Pulse wave, fatigue, visual display terminal (VDT), pulse wave characteristic values

DOI: 10.3233/BME-151381

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S889-S894, 2015

Authors: Chen, Xiaoyan | Lv, Xinqiang | Wang, Huaxiang

Article Type: Research Article

Abstract: Lung carcinoma has become one of the malignancies whose morbidity and mortality are growing significantly. Blood is a functional body fluid, it delivers oxygen and nutrients to the other parts of the body, and it is a pathway of tumor metastasis. This paper studies the possibility of diagnosing lung carcinoma by blood dielectric spectroscopy. Comparison experiments were carried out to trace the dielectric spectroscopy of blood with and without lung carcinoma changing at different tumor stages from 100 Hz to 100 MHz. The research results show that the discrepancy of complex permittivity between rat blood with and without lung carcinoma …becomes significant with tumor growing, which is worthy for clinical diagnosis. Show more

Keywords: Lung carcinoma, dielectric spectroscopy, blood, noninvasive detection

DOI: 10.3233/BME-151382

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S895-S901, 2015

Authors: Yan, Yonggang | Ma, Xiang | Yao, Lifeng | Ouyang, Jianfei

Article Type: Research Article

Abstract: Non-contact and remote measurements of vital physical signals are important for reliable and comfortable physiological self-assessment. We presented a novel optical imaging-based method to measure the vital physical signals. Using a digital camera and ambient light, the cardiovascular pulse waves were extracted better from human color facial videos correctly. And the vital physiological parameters like heart rate were measured using a proposed signal-weighted analysis method. The measured HRs consistent with those measured simultaneously with reference technologies (r =0.94, p <0.001 for HR). The results show that the imaging–based method is suitable for measuring the physiological parameters, and provide a reliable …and comfortable measurement mode. The study lays a physical foundation for measuring multi-physiological parameters of human noninvasively. Show more

Keywords: Biomedical engineering, noncontact cardiovascular measurement, heart rate, blood pressure, pulse wave

DOI: 10.3233/BME-151383

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S903-S909, 2015

Authors: Luo, Binhua | Zhang, Huajie | Liu, Xuhan | Rao, Rong | Wu, Yun | Liu, Wei

Article Type: Research Article

Abstract: Fluorescence dye DiR and superparamagnetic iron oxide nanoparticles (SPIONs) embedded in PEG-PLGA nanobubbles (DiR-SPIO-NBs) were produced using double emulsion method on a membrane of Shirasu porous glass (SPG). The nanobubbles encapsulated with DiR and SPIONs had a liquid core (perfluoropentane) and a PEG-PLGA shell. DiR-SPIO-NBs showed biocompatibility based on MTT cytotoxicity and hemolysis studies. The PFP encapsulated in the nanobubbles experienced phase transition under ultrasonic irradation. Nanobubbles dispersed well in saline over 3 months, and the relaxivity was 127.9 mM−1 s−1 , suggesting that it could be used as a contrast agent in MRI. The MR and fluorescence images in …vivo demonstrated that the signal intensity in the spleen and liver was significantly enhanced with the treatment of nanobubbles. In addition, results of ultrasound images suggested that the nanobubbles had persistent contrast ability. In conclusion, nanobubbles could be utilized as an US/MRI/fluorescence contrast agent. Show more

Keywords: Nanobubbles, ultrasound-triggered phase transition, multimodal contrast agent, ultrasound imaging, magnetic resonance imaging, fluorescence imaging

DOI: 10.3233/BME-151384

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S911-S916, 2015

Authors: Wang, Dongcui | Mo, Fongming | Zhang, Yangde | Yang, Chao | Liu, Jun | Chen, Zhencheng | Zhao, Jinfeng

Article Type: Research Article

Abstract: In a previous study (unpublished), Emotiv headset was validated for capturing event-related potentials (ERPs) from normal subjects. In the present follow-up study, the signal quality of Emotiv headset was tested by the accuracy rate of discriminating Major Depressive Disorder (MDD) patients from the normal subjects. ERPs of 22 MDD patients and 15 normal subjects were induced by an auditory oddball task and the amplitude of N1, N2 and P3 of ERP components were specifically analyzed. The features of ERPs were statistically investigated. It is found that Emotiv headset is capable of discriminating the abnormal N1, N2 and P3 components in …MDD patients. Relief-F algorithm was applied to all features for feature selection. The selected features were then input to a linear discriminant analysis (LDA) classifier with leave-one-out cross-validation to characterize the ERP features of MDD. 127 possible combinations out of the selected 7 ERP features were classified using LDA. The best classification accuracy was achieved to be 89.66%. These results suggest that MDD patients are identifiable from normal subjects by ERPs measured by Emotiv headset. Show more

Keywords: Emotiv system, major depressive disorder, event-related potential

DOI: 10.3233/BME-151385

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S917-S923, 2015

Authors: Zhu, Junjiang | He, Lingsong | Du, Jianhao

Article Type: Research Article

Abstract: This paper improves the learning dictionary construction method for morphological component analysis (MCA) to separate the atrial and ventricular signals. The incoherence is added into the objective function to reduce the sparsity ratio between the atrial and ventricular dictionaries. By using the dictionaries, atrial and ventricular activities are separated from the location of the coefficients. We test the methods on both the synthetic and real atrial data. While extracting AFW from synthetic data, we use the Poisson relation as the measure. The result shows that we can obtain greater relation value using the method this paper presents than using the …methods of ABS and PCA. We also conduct spectral analysis on AFW extracted from real atrial data. Show more

Keywords: Atrial fibrillation wave, morphological component analysis, sparse, learned dictionary

DOI: 10.3233/BME-151386

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S925-S934, 2015

Authors: Lim, Seunghyun | Kim, Hyunho | Song, Haryong | Cho, Dong-il “Dan” | Ko, Hyoungho

Article Type: Research Article

Abstract: This paper presents an analog front-end (AFE) IC design for recording biopotential signals. The AFE employs a capacitively coupled instrumentation amplifier to achieve a low-noise and high-common mode rejection ratio (CMRR) system. A ripple reduction loop is proposed to reduce the ripple generated by the up-modulating chopper. The low frequency noise is attenuated by an input AC coupling capacitor, and is attenuated again by a DC servo loop. The proposed AFE features a differential gain of 71 dB, and a CMRR of 89 dB, at 50 Hz. Furthermore, the proposed AFE can robustly acquire biopotential signals even in the presence …of an input offset and ripples. Show more

Keywords: Biopotential analog front-end (AFE), electroencephalograph (EEG), electrocardiogram (ECG), ripple reduction loop, DC servo loop

DOI: 10.3233/BME-151387

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S935-S941, 2015

Authors: Zhi, Deng

Article Type: Research Article

Abstract: Fiducial Localization Error (FLE) is one of the major reasons of inaccuracy in point-based spatial registration of Image-Guided Neurosurgery System (IGNS), and minimizing FLE is the fundamental way to improve spatial registration accuracy. A reliable estimation of FLE is needed, as it cannot be measured directly in real application of IGNS. In this paper, we propose a method to estimate the FLE in a point-based registration of IGNS. Test fiducial point sets were generated in one coordinate system around the given fiducial point set by utilizing simple random sampling. Further, these points were registered to the fiducial point set in …the other coordinate system. The average position of the test fiducial point sets with small FRE are calculated and its displacement from the given fiducial point set is the parameter used to estimate the FLE of each fiducial point. The correlation between the displacement and the FLE of each fiducial point is greater than 0.75 when nine or more fiducial points were utilized. This correlation gradually increases up to 0.9 with the increase of the number of fiducial points. Show more

Keywords: Image-guided neurosurgery, fiducial localization error, point-based registration

DOI: 10.3233/BME-151388

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S943-S949, 2015

Authors: He, YiFan | Meng, Hong | Dong, YinMao

Article Type: Research Article

Abstract: Laser Doppler imagery is a contemporary form biomedical science specializing in non-evasive micro-circulation investigation. This paper outlines the process and results of applying twelve different test samples to mouse skin to collect data variation of micro-circulation, then judge the effects of different formulas in skin health improvement. More specifically, it is said [15] that micro-circulation is associated with anti-aging (otherwise known as micro-circulation acceleration) by the way of improvement of nutrition supply and hazard substance elimination, has some effects of skin anti-aging. In this paper, compared with Group 0 (the blank group), Group 1, and Group 2 formulas have …statistically significant differences in skin micro-circulation perfusion, which implies that those two groups are provided with better anti-aging formulas. So, Group 1’s formula and Group 2’s formula have the most significant positive effect on the skin health. Show more

Keywords: Laser doppler imager, skin micro-circulatory perfusion, skin health, Chinese medicine formulas

DOI: 10.3233/BME-151389

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S951-S958, 2015

Authors: Wu, Hao | Shen, Guofeng | Chen, Yazhu

Article Type: Research Article

Abstract: Electromagnetic compatibility (EMC) is a key issue in the design and development of safe and effective medical instruments. The treatment probes of high intensity focused ultrasound (HIFU) systems not only receive and transmit electromagnetic waves, but also radiate ultrasound waves, resulting in electromagnetic coupling. In this paper, an electromagnetic shielding method involving the enclosure of the probe in a copper wire mesh was introduced. First, sound pressure distribution simulations and measurements were performed using a hydrophone in order to evaluate the effects of the wire mesh on the acoustic performance of the HIFU system. The results indicated that the wire …mesh did not disturb the normalized sound pressure field. In addition, the attenuation of the maximum pressure in the focal plane was equal to 6.2%. Then, the electronic emission level was tested in a chamber. After the implementation of the wire mesh, the 10-100 MHz frequency band radiation was suppressed, and the HIFU system satisfied the national EMC standards. Show more

Keywords: High intensity focused ultrasound, electromagnetic compatibility, radiated emission, radio frequency shielding

DOI: 10.3233/BME-151390

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S959-S966, 2015

Authors: An, Yong | Wang, Manning | Song, Zhijian

Article Type: Research Article

Abstract: This study presents a novel spatial registration method of Image-guided neurosurgery system (IGNS) based on stereo-vision. Images of the patient’s head are captured by a video camera, which is calibrated and tracked by an optical tracking system. Then, a set of sparse facial data points are reconstructed from them by stereo vision in the patient space. Surface matching method is utilized to register the reconstructed sparse points and the facial surface reconstructed from preoperative images of the patient. Simulation experiments verified the feasibility of the proposed method. The proposed method it is a new low-cost and easy-to-use spatial registration method …for IGNS, with good prospects for clinical application. Show more

Keywords: Image-guided neurosurgery system, stereo vision, spatial registration, iterative closest point

DOI: 10.3233/BME-151391

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S967-S973, 2015

Authors: Wang, Rui | Li, Rui | Lei, Yanyan | Zhu, Quing

Article Type: Research Article

Abstract: Support vector machine (SVM) is one of the most effective classification methods for cancer detection. The efficiency and quality of a SVM classifier depends strongly on several important features and a set of proper parameters. Here, a series of classification analyses, with one set of photoacoustic data from ovarian tissues ex vivo and a widely used breast cancer dataset- the Wisconsin Diagnostic Breast Cancer (WDBC), revealed the different accuracy of a SVM classification in terms of the number of features used and the parameters selected. A pattern recognition system is proposed by means of SVM-Recursive Feature Elimination (RFE) with the …Radial Basis Function (RBF) kernel. To improve the effectiveness and robustness of the system, an optimized tuning ensemble algorithm called as SVM-RFE(C) with correlation filter was implemented to quantify feature and parameter information based on cross validation. The proposed algorithm is first demonstrated outperforming SVM-RFE on WDBC. Then the best accuracy of 94.643% and sensitivity of 94.595% were achieved when using SVM-RFE(C) to test 57 new PAT data from 19 patients. The experiment results show that the classifier constructed with SVM-RFE(C) algorithm is able to learn additional information from new data and has significant potential in ovarian cancer diagnosis. Show more

Keywords: Support vector machines, ovarian cancer detection, feature selection, correlation filter, SVM-RFE

DOI: 10.3233/BME-151392

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S975-S981, 2015

Authors: Feng, Chaolu | Zhao, Dazhe

Article Type: Research Article

Abstract: A grid-driven gridding (GDG) method is proposed to uniformly re-sample non-Cartesian raw data acquired in PROPELLER, in which a trajectory window for each Cartesian grid is first computed. The intensity of the reconstructed image at this grid is the weighted average of raw data in this window. Taking consider of the single instruction multiple data (SIMD) property of the proposed GDG, a CUDA accelerated method is then proposed to improve the performance of the proposed GDG. Two groups of raw data sampled by PROPELLER in two resolutions are reconstructed by the proposed method. To balance computation resources of the GPU …and obtain the best performance improvement, four thread-block strategies are adopted. Experimental results demonstrate that although the proposed GDG is more time consuming than traditional DDG, the CUDA accelerated GDG is almost 10 times faster than traditional DDG. Show more

Keywords: Gridding, magnetic resonance reconstruction, uniform re-sampling, CUDA acceleration

DOI: 10.3233/BME-151393

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S983-S989, 2015

Authors: Lu, Meng

Article Type: Research Article

Abstract: Diffusion tensor imaging allows for the non-invasive in vivo mapping of the brain tractography. However, fiber bundles have complex structures such as fiber crossings, fiber branchings and fibers with large curvatures that tensor imaging (DTI) cannot accurately handle. This study presents a novel brain white matter tractography method using Q-ball imaging as the data source instead of DTI, because QBI can provide accurate information about multiple fiber crossings and branchings in a single voxel using an orientation distribution function (ODF). The presented method also uses graph theory to construct the Bayesian model-based graph, so that the fiber tracking between two …voxels can be represented as the shortest path in a graph. Our experiment showed that our new method can accurately handle brain white matter fiber crossings and branchings, and reconstruct brain tractograhpy both in phantom data and real brain data. Show more

Keywords: Brain white matter, graph theory, QBI, tractography, Bayesian model

DOI: 10.3233/BME-151394

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S991-S1000, 2015

Authors: Kim, Ji-Sun | Oh, Han-Byeol | Kim, A-Hee | Kim, Jun-Sik | Lee, Eun-Suk | Goh, Bong-Jun | Lee, Tae-Hee | Chung, Soon-Cheol | Jun, Jae-Hoon

Article Type: Research Article

Abstract: Laser can precisely deliver quantitative energy to a desired region in a non-contact way. Since it can stimulate regions and minutely control parameters such as the intensity, duration and frequency of stimulus, laser is often used for the areas such as low power laser treatment and clinical physiology. This study proposes simulation using pulse diode laser with reliable output and identifies laser parameters that can present a variety of somesthesis. It is found that typically, as frequency and energy increase, the ratio of feeling senses increases, and dominant sense moves from the sense of heat through tactile sense to pain. …This study will be baseline data for studies of the sense of heat, tactile sense and pain, contribute to studying neurophysiology sector and be applied to basic clinical research. Show more

Keywords: Biostimulation, heat and pain sense, laser beam physical parameters, laser-tissue interaction, tactile

DOI: 10.3233/BME-151395

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1001-S1008, 2015

Authors: Teng, Yueyang | Zhang, Yaonan | Kang, Yan

Article Type: Research Article

Abstract: Segmentation technique is widely accepted to reduce noise propagation from transmission scanning for positron emission tomography. The conventional routine is to sequentially perform reconstruction and segmentation. A smoothness penalty is also usually used to reduce noise, which can be imposed to both the ML and WLS estimators. In this paper we replace the smoothness penalty by a segmentation penalty that biases the object toward piecewise-homogeneous reconstruction. Two updating algorithms are developed to solve the penalized ML and WLS estimates, which monotonically decrease the cost functions. Experimental results on simulated phantom and real clinical data were both given to demonstrate the …effectiveness and efficiency of the algorithms which were proposed. Show more

Keywords: Segmentation penalty, fuzzy c-means clustering (FCM), space alternating descent, auxiliary function

DOI: 10.3233/BME-151396

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1009-S1018, 2015

Authors: Duan, Lijuan | Ge, Hui | Ma, Wei | Miao, Jun

Article Type: Research Article

Abstract: This paper aims to solve automated feature selection problem in brain computer interface (BCI). In order to automate feature selection process, we proposed a novel EEG feature selection method based on decision tree (DT). During the electroencephalogram (EEG) signal processing, a feature extraction method based on principle component analysis (PCA) was used, and the selection process based on decision tree was performed by searching the feature space and automatically selecting optimal features. Considering that EEG signals are a series of non-linear signals, a generalized linear classifier named support vector machine (SVM) was chosen. In order to test the validity of …the proposed method, we applied the EEG feature selection method based on decision tree to BCI Competition II datasets Ia, and the experiment showed encouraging results. Show more

Keywords: Decision tree, feature selection, optimal features, EEG, brain-computer interface

DOI: 10.3233/BME-151397

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1019-S1025, 2015

Authors: Fan, Zhongyin | Xie, Yaoqin

Article Type: Research Article

Abstract: Computed tomography (CT) has been widely used to acquire volumetric anatomical information in the diagnosis and treatment of illnesses in many clinics. However, the ART algorithm for reconstruction from under-sampled and noisy projection is still time-consuming. It is the goal of our work to improve a block-wise approximate parallel implementation for the ART algorithm on CUDA-enabled GPU to make the ART algorithm applicable to the clinical environment. The resulting method has several compelling features: (1) the rays are allotted into blocks, making the rays in the same block parallel; (2) GPU implementation caters to the actual industrial and medical application …demand. We test the algorithm on a digital shepp-logan phantom, and the results indicate that our method is more efficient than the existing CPU implementation. The high computation efficiency achieved in our algorithm makes it possible for clinicians to obtain real-time 3D images. Show more

Keywords: CT, ART, GPU, block-wise, approximate parallel

DOI: 10.3233/BME-151398

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1027-S1035, 2015

Authors: Wu, Qian | Cao, Ruifen | Pei, Xi | Jia, Jing | Hu, Liqin

Article Type: Research Article

Abstract: Radiotherapy treatment plan may be replanned due the changes of tumors and organs at risk (OARs) during the treatment. Deformable image registration (DIR) based Computed Tomography (CT) contour propagation in the routine clinical setting is expected to reduce time needed for necessary manual tumors and OARs delineations and increase the efficiency of replanning. In this study, a DIR method was developed for CT contour propagation. Prior structure delineations were incorporated into Demons DIR, which was represented by adding an intensity matching term of the delineated tissues pairs to the energy function of Demons. The performance of our DIR was evaluated …with five clinical head-and-neck and five lung cancer cases. The experimental results verified the improved accuracy of the proposed registration method compared with conventional registration and Demons DIR. Show more

Keywords: Computed tomography, deformable image registration, structure delineation, contour propagation

DOI: 10.3233/BME-151399

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1037-S1044, 2015

Authors: Li, Fenghuan | Zheng, Dequan | Zhao, Tiejun

Article Type: Research Article

Abstract: Arrhythmia diagnosis is very significant to ensure human health. In this paper, a new model is developed for arrhythmia diagnosis. A salient feature of the algorithm is a synergistic combination of statistical and fuzzy set-based techniques. It is distribution-free and is realized in an unsupervised mode. Arrhythmia diagnosis is viewed as a certain statistical hypothesis testing. ‘Abnormal’ is typically a much complex concept, so it can be described with the technology of fuzzy sets which bring a facet of robustness to the overall scheme and play an important role in the successive step of hypothesis testing. Intensive fuzzification is engaged …in parameters determination which is self-adaptive and no parameter needs to be specified by the user. The algorithm is validated with a number of experiments, which prove its effectiveness for arrhythmia diagnosis. Show more

Keywords: Arrhythmia diagnosis, fuzzy sets, statistical testing, self-adaptive, distribution-free

DOI: 10.3233/BME-151400

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1045-S1052, 2015

Authors: Tang, Xiaoying | Zhang, Xiying | Cai, Dongqin | Du, Juncheng | Liu, Weifeng

Article Type: Research Article

Abstract: Epilepsy is a neurological disorder characterized by the sudden abnormal discharging of brain neurons that can lead to encephalographic (EEG) abnormalities. In this study, data was obtained from epileptic patients with intracranial depth electrodes and analyzed using wavelet entropy algorithms in order to locate the epileptic foci. Significant increases in the wavelet entropy of the epileptic signals were identified during multiple episodes of clinical seizures. The results indicated that the algorithm was capable of identifying entropy changes in the epileptic sources. Furthermore, the correlations among the electrocorticogram (ECoG) signals of different channels determined using the amplitude-amplitude coupling method verified that …the epileptic foci exhibited significantly higher coupling strengths. Thus, cross frequency coupling (CFC) could be an inspiration to energy and signal transitive mode of seizure and, thereby, improve diagnostic processes. Show more

Keywords: Epilepsy, ECoG, wavelet entropy, correlation, CFC

DOI: 10.3233/BME-151401

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1053-S1058, 2015

Authors: Xia, Yong | Han, Junze | Wang, Kuanquan

Article Type: Research Article

Abstract: Based on the idea of telemedicine, 24-hour uninterrupted monitoring on electrocardiograms (ECG) has started to be implemented. To create an intelligent ECG monitoring system, an efficient and quick detection algorithm for the characteristic waveforms is needed. This paper aims to give a quick and effective method for detecting QRS-complexes and R-waves in ECGs. The real ECG signal from the MIT-BIH Arrhythmia Database is used for the performance evaluation. The method proposed combined a wavelet transform and the K-means clustering algorithm. A wavelet transform is adopted in the data analysis and preprocessing. Then, based on the slope information of the filtered …data, a segmented K-means clustering method is adopted to detect the QRS region. Detection of the R-peak is based on comparing the local amplitudes in each QRS region, which is different from other approaches, and the time cost of R-wave detection is reduced. Of the tested 8 records (total 18201 beats) from the MIT-BIH Arrhythmia Database, an average R-peak detection sensitivity of 99.72 and a positive predictive value of 99.80% are gained; the average time consumed detecting a 30-min original signal is 5.78s, which is competitive with other methods. Show more

Keywords: ECG, detection of QRS-complex and R-wave, wavelet transform, k-means clustering

DOI: 10.3233/BME-151402

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1059-S1065, 2015

Authors: Li, Yifeng | Zhang, Lihui | Li, Baohui | Wei, Xiaoyang | Yan, Guiding | Geng, Xichen | Jin, Zhao | Xu, Yan | Wang, Haixia | Liu, Xiaoyan | Lin, Rong | Wang, Quan

Article Type: Research Article

Abstract: This paper briefly describes the basic principle of wavelet packet analysis, and on this basis introduces the general principle of wavelet packet transformation for signal den-noising. The dynamic EEG data under +Gz acceleration is made a de-noising treatment by using wavelet packet transformation, and the de-noising effects with different thresholds are made a comparison. The study verifies the validity and application value of wavelet packet threshold method for the de-noising of dynamic EEG data under +Gz acceleration.

Keywords: Wavelet packet, EEG, threshold, de-noising

DOI: 10.3233/BME-151403

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1067-S1075, 2015

Authors: Moreno-Alsasua, L. | Garcia-Zapirain, B. | Mendez-Zorrilla, A.

Article Type: Research Article

Abstract: This paper presents a technical solution that analyses sleep signals captured by biomedical sensors to find possible disorders during rest. Specifically, the method evaluates electrooculogram (EOG) signals, skin conductance (GSR), air flow (AS), and body temperature. Next, a quantitative sleep quality analysis determines significant changes in the biological signals, and any similarities between them in a given time period. Filtering techniques such as the Fourier transform method and IIR filters process the signal and identify significant variations. Once these changes have been identified, all significant data is compared and a quantitative and statistical analysis is carried out to determine the …level of a person’s rest. To evaluate the correlation and significant differences, a statistical analysis has been calculated showing correlation between EOG and AS signals (p=0,005), EOG, and GSR signals (p=0,037) and, finally, the EOG and Body temperature (p=0,04). Doctors could use this information to monitor changes within a patient. Show more

Keywords: EOG, GSR, AS, body temperature, sleep quality, processing

DOI: 10.3233/BME-151404

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1077-S1085, 2015

Authors: Shin, Seung-Won | Kim, Kyeong-Seop | Song, Chul-Gyu | Lee, Jeong-Whan | Kim, Jeong-Hwan | Jeung, Gyeo-Wun

Article Type: Research Article

Abstract: The very first step to process electrocardiogram (ECG) signal is to eliminate baseline wandering interference that is usually caused by electrode-skin impedance mismatch, motion artifacts due to a patient’s body moment or respiratory breathing. A new method is thus suggested to remove baseline wandering in ECG by improving the detrending method that was originally proposed for eliminating slow non-stationary trends from heart rate variability (HRV). In our proposed method, a global trend is estimated in terms of baseline wandering by merging the local trend based on an ECG segment that represents a part of the ECG signal. The experimental results …show that the improved detrending method can efficiently resolve baseline wandering without distorting any morphological characteristic embedded in the ECG signal in no time delay manner. Show more

Keywords: Electrocardiogram (ECG), baseline wandering, detrending, heart rate variability (HRV), high-pass filter

DOI: 10.3233/BME-151405

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1087-S1093, 2015

Authors: Yin, Hong | Zhu, Xiaoqian | Ma, Shaodong | Yang, Shuqiang | Chen, Liqian

Article Type: Research Article

Abstract: The heart sound signal is a reflection of heart and vascular system motion. Long-term continuous electrocardiogram (ECG) contains important information which can be helpful to prevent heart failure. A single piece of a long-term ECG recording usually consists of more than one hundred thousand data points in length, making it difficult to derive hidden features that may be reflected through dynamic ECG monitoring, which is also very time-consuming to analyze. In this paper, a Dynamic Time Warping based on MapReduce (MRDTW) is proposed to make prognoses of possible lesions in patients. Through comparison of a real-time ECG of a patient …with the reference sets of normal and problematic cardiac waveforms, the experimental results reveal that our approach not only retains high accuracy, but also greatly improves the efficiency of the similarity measure in dynamic ECG series. Show more

Keywords: Similarity, DTW, ECG series, MapReduce, parallel

DOI: 10.3233/BME-151406

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1095-S1105, 2015

Authors: Wang, Niannian | Zhang, Li | Liu, Guozhong

Article Type: Research Article

Abstract: Recently, exploring the cognitive functions of the brain by establishing a network model to understand the working mechanism of the brain has become a popular research topic in the field of neuroscience. In this study, electroencephalography (EEG) was used to collect data from subjects given four different mathematical cognitive tasks: recite numbers clockwise and counter-clockwise, and letters clockwise and counter-clockwise to build a complex brain function network (BFN). By studying the connectivity features and parameters of those brain functional networks, it was found that the average clustering coefficient is much larger than its corresponding random network and the average shortest …path length is similar to the corresponding random networks, which clearly shows the characteristics of the small-world network. The brain regions stimulated during the experiment are consistent with traditional cognitive science regarding learning, memory, comprehension, and other rational judgment results. The new method of complex networking involves studying the mathematical cognitive process of reciting, providing an effective research foundation for exploring the relationship between brain cognition and human learning skills and memory. This could help detect memory deficits early in young and mentally handicapped children, and help scientists understand the causes of cognitive brain disorders. Show more

Keywords: EEG, brain function network, small-word property, cognitive memory

DOI: 10.3233/BME-151407

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1107-S1114, 2015

Authors: Li, Yan | Chen, Yuanyuan | Lv, Xiaoning | Yang, Yang | Li, Jing | Hao, Chenru | Li, Minggao | Pu, Fang

Article Type: Research Article

Abstract: Unrecognized spatial disorientation (SD) which is intimately linked with brain cognitive function is always a fatal issue for the safety of pilots. To explore its effects on human brain cognitive functions, electroencephalography (EEG) functional network analysis methods were adopted to examine topological changes in the connection of cognitive regions when experiencing unrecognized SD. Twelve male pilots participated in the study. They were subjected to a SD scene, namely visual rotation, which evoked unrecognized SD. For the main EEG frequency intervals, the phase lag index (PLI) and normalized mutual information (NMI) were calculated to quantify the EEG data. Then weighted connectivity …networks were constructed and their properties were characterized in terms of an average clustering coefficient and global efficiency. A T-test was performed to compare PLI, NMI and network measures under unrecognized SD and non-SD conditions. It indicated a weak functional connectivity level in the theta band under unrecognized SD based on the significant decrease of mean values of PLI and NMI (p<0.05). Meanwhile, both the average clustering coefficient and global efficiency in the theta band reduced under the unrecognized SD condition. The decrease of the average clustering coefficient and global efficiency demonstrates a lack of small-world characteristics and a decline in processing efficiency of brain cognitive regions. All the experimental results show that unrecognized SD may have a negative effect on brain functional networks in the theta band. Show more

Keywords: Unrecognized spatial disorientation, cognitive function, EEG, network

DOI: 10.3233/BME-151408

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1115-S1124, 2015

Authors: Yu, Weiwei | Feng, Huashan | Feng, Yangyang | Madani, Kurosh | Sabourin, Christophe

Article Type: Research Article

Abstract: Motor imagery EEG-based BCI has advantages in the assistance of human control of peripheral devices, such as the mobile robot or wheelchair, because the subject is not exposed to any stimulation and suffers no risk of fatigue. However, the intensive training necessary to recognize the numerous classes of data makes it hard to control these nonholonomic mobile systems accurately and effectively. This paper proposes a new approach which combines motor imagery EEG with the Adaptive Neural Fuzzy Inference System. This approach fuses the intelligence of humans based on motor imagery EEG with the precise capabilities of a mobile system based …on ANFIS. This approach realizes a multi-level control, which makes the nonholonomic mobile system highly controllably without stopping or relying on sensor information. Also, because the ANFIS controller can be trained while performing the control task, control accuracy and efficiency is increased for the user. Experimental results of the nonholonomic mobile robot verify the effectiveness of this approach. Show more

Keywords: BCI, motor imagery EEG, ANFIS, nonholonomic mobile system

DOI: 10.3233/BME-151409

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1125-S1133, 2015

Authors: Wang, Gang | Shepherd, Simon J. | Beggs, Clive B. | Rao, Nini | Zhang, Ying

Article Type: Research Article

Abstract: The use of electroencephalograms (EEGs) to diagnose and analyses Alzheimer’s disease (AD) has received much attention in recent years. The sample entropy (SE) has been widely applied to the diagnosis of AD. In our study, nine EEGs from 21 scalp electrodes in 3 AD patients and 9 EEGs from 3 age-matched controls are recorded. The calculations show that the kurtoses of the AD patients’ EEG are positive and much higher than that of the controls. This finding encourages us to introduce a kurtosis-based de-noising method. The 21-electrode EEG is first decomposed using independent component analysis (ICA), and second sort them …using their kurtoses in ascending order. Finally, the subspace of EEG signal using back projection of only the last five components is reconstructed. SE will be calculated after the above de-noising preprocess. The classifications show that this method can significantly improve the accuracy of SE-based diagnosis. The kurtosis analysis of EEG may contribute to increasing the understanding of brain dysfunction in AD in a statistical way. Show more

Keywords: Electroencephalogram (EEG), Alzheimer’s disease (AD), kurtosis, sample entropy (SE)

DOI: 10.3233/BME-151410

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1135-S1148, 2015

Authors: Li, Hui | Peng, Cheng | Ye, Datian

Article Type: Research Article

Abstract: In this paper we report a detection method for different sleep stages and it is based on a single-channel electroencephalogram (EEG) system. The system is simple and can be easily setup in homes to perform sleep EEG recording, overnight sleep EEG automatic staging, and sleep quality evaluation. EEG data of 14 sleeping subjects were recorded through the entire night. All subjects were within the age group of 20-30 years and having no significant sleep disorders. To analyze the EEG data, it is segmented into equal time intervals. This is followed by calculation of Sample Entropy (SampEn) for each section, and …the SampEn’s statistical characteristics, such as the median, upper quartile, lower quartile and inter-quartile range. The sleep data were divided into training group (7 cases) and test group (7 cases). Sleep stages’ quantitative ranges of training group referring to ZEO results were extracted and the quantization range used to sleep staging EEG data. Both the training group and test group results were close to ZEO results. It suggested that the statistical characteristics of Sample Entropy could be used as a criterion for sleep staging and evaluation. Show more

Keywords: Electroencephalogram (EEG), sleep staging, sample entropy (SampEn), median, inter-quartile range (IQR)

DOI: 10.3233/BME-151411

Citation: Bio-Medical Materials and Engineering, vol. 26, no. s1, pp. S1149-S1156, 2015