Journal of Biomimetics, Biomaterials and Biomedical Engineering Vol. 40

Abstract: The purpose of this study was to examine the acute effects of different stretching techniques on performance and lower limb kinematics, kinetics and muscle activities during vertical jump in female aerobics athletes. 10 female college aerobics athletes participated in this study. Three-dimensional kinematic and kinetic data, as well as electromyography of rectus femoris, biceps femoris and gastrocnemius medialis were collected using Vicon motion analysis system, Kistler force plate and Wireless surface electromyographic system respectively during the test. No significant differences in jump height had been determined among these 3 warm-up methods. Hip peak flexion and internal rotation angles decreased significantly after BSM and peak adduction angle decreased significantly after SSM and BSM during landing. Knee peak flexion and internal rotation angles increased significantly after SSM and BSM during take-off. Also, BSM showed significantly greater peak flexion compared with SSM. Ankle peak plantarflexion angle increased significantly after BSM. In addition, BSM showed significantly greater improvement in the variation range than SSM except for the ankle int-external rotation. Existence of no significant differences in the peak value of vertical ground reaction force during take-off and landing phase had been determined among these 3 warm-up methods, and muscle activities of rectus femoris, biceps femoris and gastrocnemius medialis were likewise not significantly different. The results of this study suggest that it would be suitable for female aerobics athletes to perform ballistic stretching in warm-up in order to improve flexibility without decreasing the following vertical jumping event and may also reduce the risk of ankle sprain injury.

Abstract: The purpose of this study was to determine whether enhancement of calf muscular strength can produce influence on plantar pressure in barefoot running. Ten healthy male subjects (age:22±2.5 years, height: 1.76±0.4m, body mass: 65±2.5kg) participate this experiment enduring 8-week strength training adopting by calf raise movement on calf muscle. A medical ultrasonic instrument (Q6, China) was used to observe the variation of calf muscular morphology. A plantar pressure plate ( Novel Emed, Germany) was used to collect the variation of 8-region plantar pressure. After 8-week strength training, a significant increasing trend between pre-and post-strength training in subject`s pinnation angle (PA) of the gastrocnemius was found. Under strength training, there are some significant variations between pre-and post-plantar pressure. The start point of center of pressure (COP) gradually forward (middle foot 80%, forefoot 20%); the peak pressure of subject`s heel foot (HF) significantly lower; the maximal force in second-third metatarsal (M 2-3), medial foot (MF) and HF significantly decrease; the contact area in other toe (OT) significantly increase as well as MF and HF significantly decrease; the time-force integral in M2-3 and HF significantly lower and in MF significantly enhance. These results suggest, the enhancement of calf muscular strength may produce positively influence on beginning transitional process from shod running to barefoot running and is also worth to as a feasible way to recommend. However, the effects of strength straining on plantar pressure do not fully explore and still need to deeply explore own to existing limitations.

Abstract: The aim of the present study is to investigate the comparison between the biomechanical behavior of the dental prosthesis composed of three implants replacing successively the premolar and two molars and the dental bridge located between two implants. Both dental structures were subjected to the same masticatory loading (Corono-apical, Linguo-buccal and Disto- mesial). Three-dimensional finite element models of dental structures were developed to determine the stress distribution under simulated applied loads. In this study the biomechanical behavior of prosthetics dental crowns subjected to static loads in contact with the jawbone has been highlighted. Biomechanical simulations indicated that the equivalent stresses in the dental bridge are greater than that produced in the dental prosthesis. The dental bridge can be assimilated to a beam at the embedded ends, subjected to the bending.

Abstract: In the simplest words, a bio-sensor is an analytic device. In recent years, bio-sensors have shown emerging contribution in medical diagnosis, drug discovery, and treatment process. In this regards, continuous research is ongoing and many more features are being added in the sensing technologies. Optical sensing technology is no more bound in research area but also in the commercial use for the betterment of mankind. There are different types of bio-sensors particularly optical which have already been developed and research is going to expand many more of them. Sensing applications are not limited in glucose, DNA, cancer cell detection, drug discovery, immunological, Hepatitis B virus, and enzyme detection but also many more development is knocking at the door. Therefore, this review paper is focused on the applications and functions of bio-sensors (especially optical) in medical diagnostics and treatment.

Abstract: The paper presents a comparative study of three fiber optic sensors based on the fiber Bragg grating (FBG). The basic monitored parameter is the respiratory rate of the human body. Fiber-optic sensors are immune to electromagnetic interference (EMI). This fact singles them out as ideal for use in magnetic resonance environments (typically in MRI - magnetic resonance imaging) as a prediction of hyperventilation states in patients. These patient conditions arise as a result of the closed tunnel environment in MR scanners. The results (10 volunteers with written consent) were compared with the results using the conventional respiratory belt (RB) in a laboratory environment and processed using the objective Bland-Altman (B-A) method.

Abstract: Electromyogram (EMG) recordings are often corrupted by the wide range of artifacts, which one of them is power line interference (PLI). The study focuses on some of the well-known signal processing approaches used to eliminate or attenuate PLI from EMG signal. The results are compared using signal-to-noise ratio (SNR), correlation coefficients and Bland-Altman analysis for each tested method: notch filter, adaptive noise canceller (ANC) and wavelet transform (WT). Thus, the power of the remaining noise and shape of the output signal are analysed. The results show that the ANC method gives the best output SNR and lowest shape distortion compared to the other methods.

Abstract: The cardiac signal is very important for the heart disease diagnosis and evaluation. The noise cancelation represent one of the most preprocessing step in ECG signal processing, usually, this signal is very sensitive and varies with time. The ECG signal is mostly contaminated by different signals like Power line noise signal, Baseline signal and muscle signal. The power line interference signal is the most effected signal on the ECG during data recording. Several papers try to cancel the noise based on different ways and to extract the useful information. In this paper a novel approach based on stone blind source extraction is used to extract the pure ECG signal from raw ECG, the main advantage of the proposed approach compared with the classical technique is to separate all the useful information without filtering or cancelling the suitable data from the recording signal. Real ECG data from MIT-BIH databases is taken and the MATLAB program is used to evaluate the experimental results. The performance of the proposed approach is measured based on SNR and MSE. The main contribution of this paper is to use Stone blind source separation technique as a first time in ECG signal analysis and prove that this method is the best technique compared with conventional ways. The obtained result proves Stone BSS technique is very efficient to remove the power line noise.

Abstract: Accurate detection of tumors in brain MR images is very important for the medical image analysis and interpretation. Tumors which are detected and treated in the early stage gives better long-term survival than those detected lately. This paper proposes a combined method of Self-Organizing –Map (SOM) and Active Contour Model (ACM) for the effective segmentation of the brain tumor from MR images. ACMs are energy-based image segmentation methods and they treat the segmentation as an optimization problem. The optimization function is formulated in terms of appropriate parameters and is designed such that the minimum value of its correspondence to a contour which is a near approximation of the real object boundary. The traditional ACMs depend on pixel intensity as well as very susceptible to parameter tuning and it turns out to be a challenge for these ACMs to deal the image objects of distinct intensities. Conversely, Neural Networks (NNs) are very effective in dealing inhomogeneities but usually results in noise due to the misclassification of pixels. Additionally, NNs deal the segmentation problems without objective function. Hence we proposed a framework for the brain tumor segmentation which integrates SOM with ACM and is termed as SOMACM. This works by exactly integrating the global information derived from the weights or prototypes of the trained SOM neurons to aid choosing whether to shrink or enlarge the present contour during the optimization process and is performed in an iterative way. The proposed method can deal with the images of complex intensity distributions, even in the presence of noise. Exploratory outcomes demonstrate the high accuracy in the segmentation results of SOMACM on different tumor images, compared to the ACM as well as the general SOM segmentation methods. Furthermore, the proposed framework is not highly sensitive to parameter tuning.

Abstract: Is PlasBeam pretreatment an efficient method to improve sealant adhesion onto the enamel surfaceThe aim of this study isto investigate the effects induced by three pretreatment techniques used to improve sealant adhesion on the enamel surface, respectively standard acid-etching, UV radiations and a new method based on plasma operating at atmospheric pressure, namely the PlasBeam method.The physical-chemical modifications induced onto the enamel surface by the above pretreatments were analyzed using Contact Angle Measurements and Diffuse Reflectance Spectroscopy.The changes in the enamel surface morphology show that the acid-etching pretreatment is mostly efficient in increasing roughness, but this method stimulates the degradation processes that are well-known and turns down the brillianceof the treated surface. On the other hand, the PlasBeam treatment brings a higher roughness at the contact area between sealant and the enamel surface, compared to the UV radiations pretreatments.Moreover, the PlasBeam improves the hydrophilic character of enamel as a practical solution in enhancing the sealant adhesion to the surface. Related to other effects, it has been noticed that thePlasBeam method generates the most reflective enamel surface, whereas the White/Yellow index reaches the minimum level after a 10 second treatment.

Abstract: The case of gingival recession has a high prevalence, about 88% of the population of the United States in one or more locations suffering from gingival recession. One of the handling cases of gingival recession is to use scaffold that includes the development of tissue and cell engineering. This study aims to determine the best composition variation scaffold of collagen-chitosan with the addition of glycerol. The process of synthesis of collagen-chitosan-glycerol scaffold using freeze dry method that can form pores on the scaffold. Characterization was also carried out on the results of the synthesis of collagen-chitosan scaffold with the addition of glycerol include the morphological characterization, tensile, cytotoxicity, swelling, degradation, and thickness. The results of morphological characterization showed pore size ranged from 26.68 - 191.7 μm with a thickness of 0.51 - 0.65 mm which was suitable for handling of gingival recession cases. The result of tensile test showed that the variation of 9: 1 has the lowest value that is 2.87 MPa where the value is close to tensile strength value for periodontal which has a value ranging from 2.75 to 5.13. The characterization of cytotoxicity shows a value that is less in line with the literature, where live cells <50%. This is because collagen and chitosan have an acidic pH so that the cells cannot reproduce. Characterization of degradation shows all the variations experienced a severe reduction process from day to day. The characterization of the swelling of all samples was equilibrated at 7 minute. Chitosan-collagen scaffold with the addition of glycerol has good potential as a scaffold candidate for gingival recession therapy based on morphological characterization (thickness and surface structure), the mechanical strength (tensile strength), degradation, and the degree of swelling.