Bio-Medical Materials and Engineering - Volume 28, issue 4

Authors: Darroudi, Ali | Parchami, Jaber | Razavi, Morteza Kafaee | Sarbisheie, Ghazaleh

Article Type: Research Article

Abstract: Objective: In this paper, an adaptive method based on error entropy criterion is presented in order to eliminate noise from Electroencephalogram (EEG) signals. Method: Conventionally, the Mean-Squared Error (MSE) criterion is the dominant criterion deployed in the adaptive filters for this purpose. By deploying MSE, only second-order moment of the error distribution is optimized, which is not adequate for the noisy EEG signal in which the contaminating noises are typically non-Gaussian. By minimizing error entropy, all moments of the error distribution are minimized; hence, using the Minimum Error Entropy (MEE) algorithm instead of MSE-based adaptive algorithms will improve …the performance of noise elimination. Results: Simulation results indicate that the proposed method has a better performance compared to conventional MSE-based algorithm in terms of signal to noise ratio and steady state error. Show more

Keywords: Adaptive filtering, entropy, LMS algorithm, MEE algorithm, noise cancellation

DOI: 10.3233/BME-171680

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 4, pp. 325-338, 2017

Authors: Bai, Ningning | Tan, Cui | Li, Qing | Xi, Zhongxian

Article Type: Research Article

Abstract: In this paper, a low-cost and multifunctional hydroxyapatite (HA)/pefloxacin (PFLX) drug eluting layer is coated on magnesium (Mg) alloy through a simple hydrothermal and dip process. The drug PFLX could provide effective prevention for bone infection and inflammation due to its broad-spectrum antibacterial property. And HA would promote the growth of new bone and further improve the biocompatibility of implants. Besides, both PFLX and HA exhibits excellent corrosion protection for Mg alloy substrate. This coating is of great value for improving the application of Mg alloy as biomaterials.

Keywords: Magnesium alloy, biomaterials, anti-corrosion, anti-infection, biocompatibility

DOI: 10.3233/BME-171681

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 4, pp. 339-345, 2017

Authors: Torrisi, L. | Scolaro, C.

Article Type: Research Article

Abstract: The physical properties of biocompatible titanium surfaces were modified using different techniques of surface treatment. Particularly the measurements of roughness and wetting ability were controlled using six different techniques: polishing, sandblasting, acid attack, laser ablation, ion implantation and nanoparticle deposition. The titanium surface wetting can be modified drastically depending on the used treatment to enhance the hydrophilic or the hydrophobic behaviour of the metallic biocompatible surface. The study demonstrates that a linear relation between roughness and contact angle occurs. Possible applications to permanent or removable prosthesis titanium based are presented and discussed.

Keywords: Titanium, prosthesis, wetting ability, roughness, surface treatment

DOI: 10.3233/BME-171687

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 4, pp. 347-359, 2017

Authors: Deng, Liqing | Li, Donghai | Yang, Zhouyuan | Xie, Xiaowei | Kang, Pengde

Article Type: Research Article

Abstract: Hydroxyapatite (HA) is a representative bone repairing biomaterial for its similar composition to human bones and teeth. However, pure HA is limited in application for some unwanted characteristic, such as it is brickle and weakness in degradation. In this study, we modified HA by doping magnesium (Mg) to the material and studied its property in vitro. Besides, we also evaluated the calvarial defect repair effect using MgHA combined with rhBMP-2 in goat model. According to our outcomes, HA composited Mg made the scaffold smooth and the pore regular. In vitro study, Mg could increase the Ca releasing, which may reflect …a faster degradation property modified by Mg. And then, MgHA improved the cell viability and proliferation. Furthermore, MgHA could increase the expression of ALP, Collagen I and VEGF protein compared with pure HA (p < 0.5 , respectively). In the vivo study, MgHA showed a better bone defect healing effect in computed tomography (CT) evaluation compared with HA (p < 0.05 ), but it was inferior to the MgHA/rhBMP-2 (p < 0.05 ). Besides, in the histological analysis, MgHA/rhBMP-2 showed the most effective bone formation outcome (p < 0.05 ), and the MgHA group was significant better than the pure HA group on osteogenesis (p < 0.05 ). Furthermore, Collagen I and VEGF mRNA expression at 12 week in MgHA/rhBMP-2 group were also significat higher than other two groups. In conclusion, Mg had effects on bone formation and angiogenesis, and MgHA/rhBMP-2 had improved the bone defect repair effect. It is worthy of being recommended to bone tissue engineering. Show more

Keywords: Bone defect repair, magnesium, hydroxyapatite, recombinant human bone morphogenetic protein-2

DOI: 10.3233/BME-171678

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 4, pp. 361-377, 2017

Authors: Němcová, Andrea | Janoušek, Oto | Vítek, Martin | Provazník, Ivo

Article Type: Research Article

Abstract: The article deals with the testing of features for fatigue detection in electrooculography (EOG) records. An optimal methodology for EOG signal acquisition is described; the Biopac data acquisition system was used. EOG signals were being recorded while 10 volunteers were watching prepared scenes. Three scenes were created for this purpose – a rotating ball, a video of driving a car, and a cross. Recorded EOG signals were processed and 20 features were extracted. The features involved blinks, slow eye movement (SEM), rapid eye movement (REM), eye instability, magnitude, and periodicity. These features were statistically tested and discussed in terms of …fatigue detection ability. Some of the features were compared with published results. Finally, the best features – fatigue indicators – were selected. Show more

Keywords: Biopac, blink, electrooculography, REM, scenes, SEM

DOI: 10.3233/BME-171683

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 4, pp. 379-392, 2017

Authors: Ju, Ke-Ju | Zhong, Ling-Ling | Ni, Xiao-Yu | Xia, Lei | Xue, Liu-Jun | Cheng, Guan-Liang

Article Type: Research Article

Abstract: Objective: This study aims to explore the application prospect of low oxygen dead space ventilation (LODSV) in evaluating vasomotor reactivity (VMR) by comparison between LODSV and breath-holding test (BHT). Methods: Outpatient or inpatient patients who underwent transcranial Doppler sonography (TCD) were enrolled into this study. These patients successively underwent BHT and LODSV. The cooperation degree, tolerance conditions and adverse reactions in patients were recorded, and VMR was calculated, compared and analyzed. Results: Patients had poor cooperation during BHT. Except for compensatory tachypnea after BHT, patients basically had no adverse reaction. The main manifestations of patients undergoing …LODSV were deepened breathing and accelerated frequency in the end of the ventilation, and increased heart rate and a slight decline in pulse oxygen that rapidly recovered after ventilation. The increase rate of blood flow velocity in patients undergoing LODSV was significantly higher than in BHT (P < 0.001 ), and its calculated VMR value was approximately 15% higher than BHT (P < 0.001 ). BHT revealed a monophasic curve that slightly descends and rapidly increases, and LODSV revealed a curve that descends for a short time and slowly increases with a platform. Conclusion: LODSV can effectively eliminate the affect of poor cooperation in patients, and avoid intolerance caused by hypoxia. Hence, VMR value is more accurate than that determined by BHT; and this can reflect the maximum reaction ability of the blood vessels. Therefore, this method has higher clinical application value. Show more

Keywords: Cerebrovascular reactivity, low oxygen dead space ventilation, breath-holding test, transcranial doppler, CO2

DOI: 10.3233/BME-171679

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 4, pp. 393-400, 2017

Authors: Uma Maheshwari, S. | Govindan, K. | Raja, M. | Raja, A. | Pravin, M.B.S. | Vasanth Kumar, S.

Article Type: Research Article

Abstract: Polyvinylalcohol (PVA) and Polyvinylpyrrolidone (PVP) blend incorporated with hydroxyapatite (HAp) and β -tricalcium phosphate (β -TCP) is electrospun as nanofibrous composite scaffolds to act as suitable template for bone tissue engineering. Microscopic and spectroscopic characterizations confirm uniform integration of the crystalline calcium phosphate ceramics in the scaffolds. PVA-PVP blends are usually amorphous in nature and addition of phosphate ceramic particles specifically HAp elevates its crystalline behavior which is substantiated by XRD details. Further incorporation of ceramics is confirmed using FT-IR as characteristic PO 4 3 − groups for HAp and β -TCP were …observed in the distinguished composites. Single glass transition temperature is observed for pure and composite blends indicating the formation of highly miscible blends. Also, addition of these ceramics augments the thermal stability of the blend scaffolds. Biocompatibility of the prepared (PVA: PVP)-HAp and (PVA: PVP)-TCP scaffolds is assessed using MG-63 Osteoblast cell lines in the time interval of 1st, 4th and 7th day. The cell viability percentage for (PVA: PVP)-HAp is high compared to β -TCP added blend composites, reinforcing the fact that scaffolds with good mechanical strength and enhanced porosity supports better cell adhesion. Show more

Keywords: Electrospinning, polymer-ceramic composites, structural characterization, biomaterial

DOI: 10.3233/BME-171682

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 4, pp. 401-415, 2017

Authors: Kang, Kyoung-Tak | Kim, Sung-Hwan | Son, Juhyun | Lee, Young Han | Koh, Yong-Gon

Article Type: Research Article

Abstract: Background: Computational models have been identified as efficient techniques in the clinical decision-making process. However, computational model was validated using published data in most previous studies, and the kinematic validation of such models still remains a challenge. Recently, studies using medical imaging have provided a more accurate visualization of knee joint kinematics. Objective: The purpose of the present study was to perform kinematic validation for the subject-specific computational knee joint model by comparison with subject’s medical imaging under identical laxity condition. Methods: The laxity test was applied to the anterior-posterior drawer under 90° flexion and the …varus–valgus under 20° flexion with a series of stress radiographs, a Telos device, and computed tomography. The loading condition in the computational subject-specific knee joint model was identical to the laxity test condition in the medical image. Results: Our computational model showed knee laxity kinematic trends that were consistent with the computed tomography images, except for negligible differences because of the indirect application of the subject’s in vivo material properties. Conclusions: Medical imaging based on computed tomography with the laxity test allowed us to measure not only the precise translation but also the rotation of the knee joint. This methodology will be beneficial in the validation of laxity tests for subject- or patient-specific computational models. Show more

Keywords: 3D imaging, computed tomography, computer simulation, knee joint, laxity test

DOI: 10.3233/BME-171686

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 4, pp. 417-429, 2017

Authors: Bozzini, Clarisa | Viscor, Ginés | Kristjánsson, Juan C. Ríos | Picasso, Emilio | Champin, Graciela | Alippi, Rosa M. | Bozzini, Carlos E.

Article Type: Research Article

Abstract: BACKGROUND: Physical activity plays a tremendous role in determining bone mechanical behavior, which is superimposed to gravidity. OBJECTIVE: Compare the geometric and material responses of the rat femur to a high intensity treadmill running training of a relatively short duration, as assessed by 3-point mechanical test. METHODS: Mature male rats (180.0 ± 30 g) were assigned (7 rats/group) to no exercise (NE) or treadmill exercise (EX). After a preconditioning period, the running speed was set at 45 cm.seg−1 during 2 wks, frequency 5 d/wk, 2-hour sessions/day. Body weight and weight of the crural quadriceps were registered at euthanasia. The right femur …was mechanically tested through 3-point bending. The left femur was ashed to estimate bone mineral content. Geometric and material bone properties were estimated directly or calculated by appropriate equations. RESULTS: 1) Final body weight was 14% reduced in EX rats, while the crural quadriceps was 47% increased. Yield and fracture loads, and structural stiffness were significantly higher in the EX rats, as were the apparent elastic modulus, the bone mineral content and the degree of mineralization. Geometric properties were not affected. CONCLUSIONS: High intensity treadmill running training increases bone strength and stiffness by increasing material stiffness and mineralization, without affecting geometric bone parameters. Show more

Keywords: Bone biomechanics, treadmill exercise, rat femur, bone strength

DOI: 10.3233/BME-171684

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 4, pp. 431-441, 2017

Authors: Salmingo, Remel Alingalan | Skytte, Tina Lercke | Traberg, Marie Sand | Mikkelsen, Lars Pilgaard | Henneberg, Kaj-Åge | Wong, Christian

Article Type: Research Article

Abstract: Perthes’ disease is a destructive hip joint disorder characterized by malformation of the femoral head in young children. While the morphological changes have been widely studied, the biomechanical effects of these changes still need to be further elucidated. The objective of this study was to develop a method to investigate the biomechanical alterations in Perthes’ disease by finite element (FE ) contact modeling using MRI. The MRI data of a unilateral Perthes’ case was obtained to develop the three-dimensional FE model of the hip joint. The stress and contact pressure patterns in the unaffected hip were well distributed. …Elevated concentrations of stress and contact pressure were found in the Perthes’ hip. The highest femoral cartilage von Mises stress 3.9 MPa and contact pressure 5.3 MPa were found in the Perthes’ hip, whereas 2.4 MPa and 4.9 MPa in the healthy hip, respectively. The healthy bone in the femoral head of the Perthes’ hip carries additional loads as indicated by the increase of stress levels around the necrotic-healthy bone interface. Identifying the biomechanical changes, such as the location of stress and contact pressure concentrations, is a prerequisite for the preoperative planning to obtain stress relief for the highly stressed areas in the malformed hip. This single-patient study demonstrated that the biomechanical alterations in Perthes’ disease can be evaluated individually by patient-specific finite element contact modeling using MRI. A multi-patient study is required to test the strength of the proposed method as a pre-surgery planning tool. Show more

Keywords: Perthes, hip joint contact modeling, orthopaedic biomechanics

DOI: 10.3233/BME-171685

Citation: Bio-Medical Materials and Engineering, vol. 28, no. 4, pp. 443-456, 2017