Bio-Medical Materials and Engineering - Volume 24, issue 6

Authors: Dinescu, Sorina | Ionita, Mariana | Pandele, Andreea Madalina | Galateanu, Bianca | Iovu, Horia | Ardelean, Aurel | Costache, Marieta | Hermenean, Anca

Article Type: Research Article

Abstract: Extensively studied nowadays, graphene oxide (GO) has a benefic effect on cell proliferation and differentiation, thus holding promise for bone tissue engineering (BTE) approaches. The aim of this study was not only to design a chitosan 3D scaffold improved with GO for optimal BTE, but also to analyze its physicochemical properties and to evaluate its cytocompatibility and ability to support cell metabolic activity and proliferation. Overall results show that the addition of GO in the scaffold's composition improved mechanical properties and pore formation and enhanced the bioactivity of the scaffold material for tissue engineering. The new developed CHT/GO 3 wt% …scaffold could be a potential candidate for further in vitro and in vivo osteogenesis studies and BTE approaches. Show more

Keywords: Chitosan, graphene oxide, 3D scaffold, biocompatibility, bone tissue engineering

DOI: 10.3233/BME-141037

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2249-2256, 2014

Authors: Bai, Xinlei | Yilin, Chen | Qi, Xufeng | Cai, Dongqing

Article Type: Research Article

Abstract: Recent studies revealed that BDNF-TrkB pathway plays an important role in cardiac microvascular endothelial cells (CMECs) mediated myocardial angiogenesis. Single-cell analysis is a powerful tool for studying gene expression in individuals since cellular heterogeneity and dynamic microenvironments which individual cell will experience. Little is currently known about the expression of BDNF and TrkB receptors at the single CMEC level. Our single-cell analysis of seven randomly selected CMECs for BDNF and TrkB receptors (FL, T1, T2) showed that under an in vitro culture environment, BDNF was expressed in two of the seven selected CMECs. None of the single CMEC expressed TrkB-FL. …TrkB-T1 was expressed in all seven selected CMECs, while, TrkB-T2 was expressed in three of these. In addition, none of single CMEC was found to express both BDNF and three TrkB receptors or BDNF and TrkB-FL simultaneously. These results suggest that a stochastic or random expression pattern for BDNF and their receptors might be set in each of the CMEC to response requirement of the time and spatial change, regulation or pathophysiological change. Show more

Keywords: Single cell, BDNF, TrkB receptor, cardiac microvascular endothelial cells

DOI: 10.3233/BME-141038

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2257-2264, 2014

Authors: Liu, Yun-Feng | Zhang, Peng-Yuan | Zhang, Qiao-Fang | Zhang, Jian-Xing | Chen, Jie

Article Type: Research Article

Abstract: Three dimensional (3D) forces are the key factors for determining movement of teeth during orthodontic treatment. Designing precise forces and torques on tooth before treatment can result accurate tooth movements, but it is too difficult to realize. In orthodontic biomechanical systems, the periodontal tissues, including bones, teeth, and periodontal ligaments (PDL), are affected by braces, and measuring the forces applied on the teeth by braces should be based on a simulated model composed of these three types of tissues. This study explores the design and fabrication of a simulated oral model for 3D orthodontic force measurements. Based on medical image …processing, tissue reconstruction, 3D printing, and PDL simulation and testing, a model for measuring force was designed and fabricated, which can potentially be used for force prediction, design of treatment plans, and precise clinical operation. The experiment illustrated that bi-component silicones with 2:8 ratios had similar mechanical properties to PDL, and with a positioning guide, the teeth were assembled in the mandible sockets accurately, and so a customized oral model for 3D orthodontic force measurement was created. Show more

Keywords: Orthodontic force measurement, oral model, reconstruction, 3D printing

DOI: 10.3233/BME-141039

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2265-2271, 2014

Authors: Kwon, Yuri | Park, Sang-Hoon | Kim, Ji-Won | Ho, Yeji | Jeon, Hyeong-Min | Bang, Min-Jung | Koh, Seong-Beom | Kim, Jong-Hyun | Eom, Gwang-Moon

Article Type: Research Article

Abstract: This study aims at the quantification of fine change in parkinsonian rigidity at the wrist during deep brain stimulation (DBS) using a portable measurement system and objective mechanical measures. The rigidity of fourteen limbs was evaluated during DBS surgery. The resistive torque to imposed movement was measured for every setting where a reduction in rigidity was perceived by a neurologist. Quantitative mechanical measures derived from experimental data included viscoelastic properties, work, impulse and mechanical impedance. Most mechanical measures could discriminate the optimal setting from baseline (electrode at stereotactic initial position without electrical stimulation) and the highest significance was achieved by …viscous damping constant (p<0.001). Spearman correlation coefficients between mechanical measures and clinical score for multiple settings (averaged for 14 limbs) were 0.51–0.77 and the best correlation was shown for viscosity (ρ=0.77±0.22). The results suggest that intraoperative quantification of rigidity during DBS surgery is possible with the suggested system and measures, which would be helpful for the adjustment of electrode position and stimulation parameters. Show more

Keywords: Intraoperative, quantification, rigidity, DBS surgery, Parkinson's disease

DOI: 10.3233/BME-141040

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2273-2281, 2014

Authors: Wanyan, Xiaoru | Zhuang, Damin | Zhang, Huan

Article Type: Research Article

Abstract: Behavioral performance, subjective assessment based on NASA Task Load Index (NASA-TLX), as well as physiological measures indexed by electrocardiograph (ECG), event-related potential (ERP), and eye tracking data were used to assess the mental workload (MW) related to flight tasks. Flight simulation tasks were carried out by 12 healthy participants under different MW conditions. The MW conditions were manipulated by setting the quantity of flight indicators presented on the head-up display (HUD) in the cruise phase. In this experiment, the behavioral performance and NASA-TLX could reflect the changes of MW ideally. For physiological measures, the indices of heart rate variability (HRV), …P3a, pupil diameter and eyelid opening were verified to be sensitive to MW changes. Our findings can be applied to the comprehensive evaluation of MW during flight tasks and the further quantitative classification. Show more

Keywords: Mental workload, physiological measures, comprehensive evaluation, flight simulation, ergonomics

DOI: 10.3233/BME-141041

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2283-2290, 2014

Authors: Kwon, Yuri | Kim, Ji-Won | Ho, Yeji | Jeon, Hyeong-Min | Bang, Min-Jung | Eom, Gwang-Moon | Koh, Seong-Beom

Article Type: Research Article

Abstract: Patients with Parkinson's disease (PD) suffer from an increased resistance to passive movement of a joint, called as rigidity. Stretch reflex and shortening reaction were suggested to be associated to the rigidity, however, the mechanism is still poorly understood. We hypothesized that the co-contraction of antagonistic muscle pairs is enhanced in patients with PD and this induces resistance persisting throughout its range of motion. To test the hypothesis, we developed a motorized device for application of passive movement of the wrist joint and investigated the co-contraction of muscles during passive movement. It consisted of a servo motor connected to a …rotating axis with a timing belt, load cell for the measurement of resistance, and other elements for the fixation of arm and hand. Repetitive passive movement was applied to the wrist joint of patients. Co-contraction of antagonistic muscle pairs was significantly greater in patients than in normal subjects (p<0.001), suggesting that the enhanced co-contraction is associated with the mechanical resistance during passive movement, i.e. rigidity. Co-contraction during extended state was greater than the other states (p<0.001), which implies that the length-feedback mechanism may play the important role in co-contraction. Show more

Keywords: Parkinson's disease, rigidity, co-contraction, motorized device, passive movement

DOI: 10.3233/BME-141042

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2291-2297, 2014

Authors: Li, Xin | Zhong, Yongmin | Jazar, Reza | Subic, Aleksandar

Article Type: Research Article

Abstract: Modeling of thermal-induced mechanical behaviors of soft tissues is of great importance for thermal ablation. This paper presents a method by integrating the heating process with thermal-induced mechanical deformations of soft tissues for simulation and analysis of the thermal ablation process. This method combines bio-heat transfer theories, constitutive elastic material law under thermal loads as well as non-rigid motion dynamics to predict and analyze thermal-mechanical deformations of soft tissues. The 3D governing equations of thermal-mechanical soft tissue deformation are discretized by using the finite difference scheme and are subsequently solved by numerical algorithms. Experimental results show that the proposed method …can effectively predict the thermal-induced mechanical behaviors of soft tissues, and can be used for the thermal ablation therapy to effectively control the delivered heat energy for cancer treatment. Show more

Keywords: Thermal ablation, soft tissue, bio-heat transfer, thermo-mechanical deformation

DOI: 10.3233/BME-141043

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2299-2310, 2014

Authors: Liu, Shuang | Wanyan, Xiaoru | Zhuang, Damin

Article Type: Research Article

Abstract: To predict changes of situation awareness (SA) for pilot operating with different display interfaces and tasks, a qualitative analysis and quantitative calculation joint SA model was proposed. Based on the situational awareness model according to the attention allocation built previously, the pilot cognitive process for the situation elements was analyzed according to the ACT-R (Adaptive Control of Thought, Rational) theory, which explained how the SA was produced. To verify the validity of this model, 28 subjects performed an instrument supervision task under different experiment conditions. Situation Awareness Global Assessment Technique (SAGAT), 10-dimensional Situational Awareness Rating Technique (10-D SART), performance measure …and eye movement measure were adopted for evaluating SAs under different conditions. Statistical analysis demonstrated that the changing trend of SA calculated by this model was highly correlated with the experimental results. Therefore the situational awareness model can provide a reference for designing new cockpit display interfaces and help reducing human errors. Show more

Keywords: Situation awareness, ACT-R, analysis model, mathematical model, ergonomics

DOI: 10.3233/BME-141044

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2311-2318, 2014

Authors: Kim, Byeong Sam | Lim, Tae-Hong | Kwon, Tae Kyu | Han, Kap-Soo

Article Type: Research Article

Abstract: This study investigated that the spinal MFs can create compressive follower loads (CFLs) in the lumbar spine in a dynamic state. Three-dimensional optimization and finite element (FE) models of the spinal system were developed and validated using reported experimental data. An optimization analysis was performed to determine the MFs that create CFLs in the lumbar spine in various sagittal postures from 10° extension to 40° flexion. Optimization solutions for the MFs, CFLs, and follower load path (FLP) location were feasible for all studied postures. The FE predictions demonstrated that MFs which created CFLs along the base spinal curve connecting the …geometrical centers or along a curve in its vicinity (within anterior or posterior shift by 2 mm) produced stable deformation of the lumbar spine in the neutral standing and flexed postures, whereas the MFs which created the smallest CFLs resulted in unstable deformation. For extended postures, however, finding CFLs creating MFs that produce stable deformation of the extended spine was not possible. The results of this study support the hypothesis that the spinal muscles may stabilize the spine via the CFL mechanism. Show more

Keywords: Compressive follower load, muscle forces, finite element model, lumbar Spine, spine biomechanics

DOI: 10.3233/BME-141045

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2319-2329, 2014

Authors: Awoukeng-Goumtcha, A. | Taddei, L. | Tostain, F. | Roth, S.

Article Type: Research Article

Abstract: This study aims to investigate the penetration of a projectile into a surrogate human tissue numerically, using Finite Element (FE) simulation. 20% Balistic Gelatin material (BG) is simulated with an elasto-plastic hydrodynamic constitutive law, and then impacted by steel spheres at different velocities. The results from the FE simulations are compared with existing experimental data and other analytical equations from the literature. To our knowledge, this is the first study to investigate a projectile penetration by numerical simulation, and then compare the results with analytical and experimental data from previous studies. This developed model gives encouraging results for further investigations …of penetrating impact of projectile in the human body. Show more

Keywords: Penetrating impact, finite element analysis, ballistic, biomechanics, human surrogate

DOI: 10.3233/BME-141046

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 2331-2339, 2014