Full Research Paper
Gait Analysis
Fatemeh Akbarifar; Mohammad Hadi Honarvar; Mostafa Haj Lotfalian
Volume 15, Issue 1 , May 2021, Pages 1-11
Abstract
Finding the center of rotation (COR) is needed for defining the anatomical axis of the skeletal system and for the kinematic calculation of joints in biomechanical studies. For this purpose, predictive and functional methods can be used. In the predictive methods, regression equations obtained from anthropometric ...
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Finding the center of rotation (COR) is needed for defining the anatomical axis of the skeletal system and for the kinematic calculation of joints in biomechanical studies. For this purpose, predictive and functional methods can be used. In the predictive methods, regression equations obtained from anthropometric measurements are used, and in the functional methods, the relative motion of the two adjacent segments is used to find COR. The purpose of this study is to formulate the circle fitting algorithm as a functional method with two analytical and optimization solutions. In order to evaluate the algorithm, error analysis was performed by both analytical and numerical methods. Also, effective factors in error estimating of COR position such as standard deviation of measurement system error (σ), rotation angle (α) and the distance between marker and COR (r), was evaluated. The results showed a high correlation (r=0.99) between analytical and numerical solution, which proved the accuracy of the error analysis. In this study, optimization method according to the accuracy of better estimates in low quantities α, less influence on high quantities σ and high speed in problem solving, can be taken into consideration to reconstruct human movements in biomechanical studies. Use of functional methods, eliminates the need for attaching markers to anatomical landmarks and provides a new development in motion data acquisition.
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Biomechanical Devices
Mohammad Khavary; Mahdi Bamdad
Volume 15, Issue 1 , May 2021, Pages 13-27
Abstract
Nowadays, one of the most effective tools for restoring patients' mobility and muscles strength is the use of stationary cycling exercises and pedaling. In this study, two methods for the treatment of lower limbs are made possible by the design, control implementation, and construction of an intelligent ...
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Nowadays, one of the most effective tools for restoring patients' mobility and muscles strength is the use of stationary cycling exercises and pedaling. In this study, two methods for the treatment of lower limbs are made possible by the design, control implementation, and construction of an intelligent exercise bike. According to the damage level, the patient will fall into the active-assisted training or passive training group. In a passive training program, patients do not have enough ability to pedal on the bike, so the motor will provide the power to reach a predefined pedaling speed. In this program, feet of patients will pedal at a constant speed above the speed patient is able to achieve compulsorily. In an active-assisted training program, the patient is already improved enough to have a higher ability to pedal at the same constant speed and the motor will provide less power according to the pedaling power of the patient. Hence, the provided power by the motor is set based on the provided force by the patient. In this study, it is aimed to design the control theory for these two treatment methods and this bike. Furthermore, speed control was done by force and speed feedback. Experimental and theoretical results showed that the implementation and equipping of stationary bike with the mentioned method has led the research to the goals of speed control for rehabilitation use. Eventually, the experimental results show an average accuracy of 98.71% for the passive method in the test sample reported in this study and 98.24% for the six tests after reaching a steady state speed. Also, these results are 96.33% for the active-assisted mode and for the test reported in this study; and 95.59% for four tests to reach the desired pedaling speed.
Full Research Paper
Biomedical Signal Processing / Medical Signal Processing / Biosignal Processing
Behnaz Sheikholeslami; Ghasem Sadeghi Bajestani; Reza Yaghoobi Karimui; Reyhaneh Zarifiyan
Volume 15, Issue 1 , May 2021, Pages 29-46
Abstract
Attention Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder that can affect people of all ages in the community, especially children, and cause changes in their behavior. Previous studies have often focused on frequency domain processing or the nonlinear dynamic aspects of EEG signals ...
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Attention Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder that can affect people of all ages in the community, especially children, and cause changes in their behavior. Previous studies have often focused on frequency domain processing or the nonlinear dynamic aspects of EEG signals such as correlation dimension, fractal dimension, Lyapunov exponent, entropy, and recurrence rate of brain processes to differentiate individuals with ADHD. In this study, we evaluate the volume of the EEG signal oscillation basin using Poincare sections in the phase space of EEG signals of people with ADHD and healthy people and sort this space as well as extract various geometric features. We present a different perspective of complexity of brain activity and the level of dynamism of people with ADHD compared to healthy individuals. Finally, by evaluating the extracted features and using the SFS algorithm based on the RBF-SVM classifier, we were able to separate people with ADHD from healthy people in the groups of children and adults, with accuracy of 93.20±2.04 and 95.60±1.13. The results of this study showed that the volume of the EEG signal oscillation basin in people with ADHD was significantly higher than healthy people, which indicates an increase in the degree of dynamism and thus a decrease in the complexity of brain activity in these people. It was also identified in this study that the increase in the volume of the EEG signal oscillation basin in children is more than adults, which indicates an increase in the level of dynamism of children compared to adults. Therefore, ADHD and age can be introduced as two important factors in changing the volume of the EEG signal oscillation basin.
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Biomedical Image Processing / Medical Image Processing
Mohamad Reza Rezaeian
Volume 15, Issue 1 , May 2021, Pages 47-58
Abstract
Molecular magnetic resonance imaging by tracking contrast agents based on magnetic resonance of the nucleus is considered a novel anatomical and functional diagnostic method in various medical applications due to its good spatial resolution and safe technology. In a magnetic resonance scanner, a spectroscopic ...
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Molecular magnetic resonance imaging by tracking contrast agents based on magnetic resonance of the nucleus is considered a novel anatomical and functional diagnostic method in various medical applications due to its good spatial resolution and safe technology. In a magnetic resonance scanner, a spectroscopic spectrum known as the Z-spectrum is obtained by applying a predominantly rectangular electromagnetic saturation pulse. At frequencies corresponding to the Larmor frequency, some amplitudes due to water saturation contrast factors are formed, representing saturation transfer’s effect due to chemical exchange (CEST). Chemical shifts, magnetic field heterogeneity and imaging process’s noise, while shifting the Larmore frequencies position, distorts the CEST effect. This noise is mainly modeled by the raisin distribution, which is an extent of Gaussian distribution. In this paper, an efficient method for reducing noise from the Z-spectrum and detecting the CEST effect is presented. Deionization is performed using the analytical model’s output resulting from solving the Bloch-McCannell equations and detecting the CEST effect by calculating the Bayesian likelihood function. The proposed method’s effectiveness for noise cancellation and detection the CEST effect was performed on real Z-spectra which is obtained from magnetic resonance scanners and data obtained from human tissue. The average performance of the proposed method is measured by relative mean square error between the real Z-spectrum and the noise in the signal to noise 10dB and the number of observations 5 was about four percent. The value of the first type of error (p-value) based on parametric data was less than 5% when the noise variance was more than 0.008 and the number of observations was more than 5. In this paper, a criterion for detecting the effect of CEST based on the mediation operator is proposed to evaluate the efficiency of the proposed method in proportion to the noise power and the number of observations.
Full Research Paper
Masume Saljuqi; Peyvand Ghaderyan
Volume 15, Issue 1 , May 2021, Pages 59-71
Abstract
In the recent years, the diagnosis of Neurodegenerative Diseases (NDDs) has been one of the most challenging problems in the medical fields. Amyotrophic Lateral Sclerosis (ALS), Parkinson's Disease (PD) and Huntington's Disease (HD) are a group of neurological disorders affecting the quality of patient’s ...
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In the recent years, the diagnosis of Neurodegenerative Diseases (NDDs) has been one of the most challenging problems in the medical fields. Amyotrophic Lateral Sclerosis (ALS), Parkinson's Disease (PD) and Huntington's Disease (HD) are a group of neurological disorders affecting the quality of patient’s life. Occurrence of these diseases is due to the deterioration of motor neurons, causing human gait disturbance and asymmetry between the right and left limbs. For this purpose, in this paper various gait signals namely stride, swing, and stance intervals (from both legs) have been decomposed using a Matching Pursuit (MP) algorithm. Then, two sets of differential and dynamic features have been extracted from the MP coefficients in order to quantify the amount of divergence between both limbs. Finally, the principal components of these features have been fed as an input to sparse Non-Negative Least Squares (NNLS) classifier. The proposed algorithm has been evaluated using the gait signals of 16 healthy control subjects, 13 patients with Amyotrophic Lateral Sclerosis (ALS), 15 patients with Parkinson’s Disease (PD) and 20 patients with Huntington’s Disease (HD). The results showed that the proposed method has achieved high average accuracy rates of 84.10%, 86.67%, and 91.43% for ALS, PD, and HD detection, respectively.
Full Research Paper
Gait Analysis
Seyed Mehran Ayati Najafabadi; Alireza Hashemi Oskooi; Seyed Masoud Rafiaei
Volume 15, Issue 1 , May 2021, Pages 73-85
Abstract
People who suffer from leg length discrepancy (LLD) due to the shortening of one side of the lower extremities change their movement pattern because of using compensatory mechanisms. Methods such as manipulating a compensating insole are used to correct the movement pattern to normal. Therefore, the ...
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People who suffer from leg length discrepancy (LLD) due to the shortening of one side of the lower extremities change their movement pattern because of using compensatory mechanisms. Methods such as manipulating a compensating insole are used to correct the movement pattern to normal. Therefore, the knowledge of movement pattern changes in with and without using of insoles can help to develop rehabilitation methods. The aim of this study was to investigate the kinematics of the lower extremities of people with leg length discrepancy during stair climbing with and without using insoles. Twenty participants including 10 normal and 10 LLD people took part in this study. Their movement on stair was recorded using a 7 camera 3-D motion analysis system. Changes in the angles of the hip, the knee and the ankle joints were calculated by the 7-member Euler model and compared by independent and paired sample t-test at 95% confidence level. The results showed that there was a significant difference between healthy people and people with LLD without using insoles. These people had higher extension of the knee, pelvis and ankle at the initial contact and toe off in sagittal plane and more knee and pelvis range of movement, less adduction of the knee and pelvis at the initial contact in frontal plane, higher internal and external rotation of pelvis at the initial contact and ankle in toe off in horizontal plane (p<0.05). The results also showed that maximum abduction of the pelvis and maximum adduction of the ankle, maximum internal rotation and the value of the angle of the knee and ankle had no significant different between normal and LLD people (p>0.05) when using insoles. Therefore, the use of insoles can correct some parameters of the movement pattern of the lower joints.
Full Research Paper
Nanobiotechnology / Bionanotechnology / Nanobiology
Mohadese Shahriaripour; Sasan Asiaei
Volume 15, Issue 1 , May 2021, Pages 87-97
Abstract
Cerium oxide nanoparticles have many applications in medicine. Particle size, shape and concentration of nanoceria are very important for biological applications and biocompatibility. The synthesis method of cerium oxide nanoparticles has an important role in determining nanoceria shape, particle size ...
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Cerium oxide nanoparticles have many applications in medicine. Particle size, shape and concentration of nanoceria are very important for biological applications and biocompatibility. The synthesis method of cerium oxide nanoparticles has an important role in determining nanoceria shape, particle size and concentration. In this project, the effective parameters in determining the concentration, size and size distribution, crystallinity and production of maximum cerium oxide produced from the reactants were simulated and tested. Since in different method, particle size control has become an important challenge, microfluidic chips were used to control particle size. Among the existing methods for nanoparticle synthesis, co-precipitation method was chosen because of its simplicity, cheapness and short time method compared with other methods. Cerium nitrate and sodium hydroxide were used as raw materials to synthesize cerium oxide nanoparticles. Simulations were performed in Comsol and then the results were used for experimental tests, comparison and validation. The nanoparticles were characterized for size and size distribution using x-ray diffraction. The results of this study showed that the use of microfluidic chips is an effective method for controling nanoparticle size. Increasing concentration of sodium hydroxide can complete reaction and have maximum efficiency and decreasing the reactives velocity can reduce the size dispersion, increases the crystallinity and particle size. The yellow precipitate produced, according to Scherer equation, contains cerium oxide nanoparticles with particle size of 1.16±0.1 nm and 85% of crystallinity.
