International Journal of Applied Electromagnetics and Mechanics - Volume 59, issue 3

Authors: Zhang, Wenguang | Tang, Jiaqi | Yin, Xuele

Article Type: Research Article

Abstract: A novel neural electrode based on small-deflection theory to reduce the tissue injury caused by micromotion was designed to improve the lifetime of neural electrode. The results of the finite element analysis revealed that the novel neural electrode showed excellent micromotion-attenuation capability. And designing a reasonable size of opening area can effectively improve neural electrode-brain tissue interface mechanical states. The novel electrode is inferred to prolong the lifetime of neural electrodes.

Keywords: Neural electrode, small-deflection theory, finite element method (FEM), micromotion

DOI: 10.3233/JAE-171058

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1065-1071, 2019

Authors: Zhang, Wenguang | Tang, Jiaqi | Li, Zhengwei

Article Type: Research Article

Abstract: In order to reveal the effects of insertion speed with hydrogel coatings on tissue injury, comparative experiments were carried out with the naked neural probes (as the reference) and probes with PVA-H coatings based on tissue injury evaluation system. It was found that the coatings of the neural probes would cause more serious tissue injury during the insertion process. And the insertion speed could alleviate the negative effects on the tissue injury caused by implantation of neural probes.

Keywords: Neural probe, tissue injury, PVA-H coatings, insertion speed

DOI: 10.3233/JAE-171104

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1073-1079, 2019

Authors: Zhang, Feng | Jiang, Changqing | Mo, Xiaolong | Liu, Yinghua | Xie, Huimin | Li, Luming

Article Type: Research Article

Abstract: Deep brain stimulation (DBS) is an effective therapy for treating neurological disorders, while magnetic resonance imaging (MRI) is a valuable method for clinical diagnosis and research. However, DBS systems in clinical MRI are under the influence of displacement force, torque and device vibration, which may be hazardous to patients after DBS implantation surgery. In this study, we evaluated these hazardous effects under 3T MRI. A set of apparatus were designed and built and the corresponding methods for safety assessment were also proposed. Results showed that the displacement force, torque and vibration of the DBS system under 3T MRI were safe. …Furthermore, this study demonstrates an example of an MRI compatibility test that can be applied to many other medical instruments. Show more

Keywords: Deep brain stimulation, magnetic resonance imaging, force, torque, vibration

DOI: 10.3233/JAE-171084

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1081-1086, 2019

Authors: Xia, Yu | Feng, Chendong | Xiong, Yinze | Luo, Yun | Li, Xiang

Article Type: Research Article

Abstract: Additive manufacturing technology has been widely used for the fabrication of porous titanium (Ti) orthopedic implants. Though high porosities and low stiffness of the scaffolds are benefit for bone ingrowth, the compressive strength and fatigue performance of the scaffolds are still necessary for load-bearing applications. In this study, a novel porous scaffold with framework structure was designed and fabricated using selective laser melting process. The mechanical properties of the porous Ti scaffolds were evaluated. The results showed that the compressive strength of the scaffolds possessing framework structure was enhanced significantly with the porosity decreased slightly. In addition to static mechanical …properties, the fatigue properties of the porous Ti scaffolds were also improved via the framework structure. Show more

Keywords: Additive manufacturing, porous titanium, compressive strength, fatigue test, framework structure

DOI: 10.3233/JAE-171197

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1087-1095, 2019

Authors: Xiong, Yinze | Gao, Ruining | Zhang, Hang | Li, Xiang

Article Type: Research Article

Abstract: A novel titanium (Ti) dental implant with pore architecture and enhanced structure was designed and fabricated using selective laser melting (SLM). Aimed at adding micro/nano structures on the porous Ti implant, alkali heat treatment was proposed. The fully interconnected porous part was in the midsection of the implant. The reinforced strut was embedded in the center of the porous part. The mechanical properties and surface morphology of the porous Ti implant were characterized. The desired micro/nano surface was obtained after alkali heat treatment. Mechanical test results showed that the ultimate strength was about 715 MPa, enough to withstand normal occlusal force …and the stiffness of the Ti dental implant was about 26 GPa. This novel porous titanium dental implant with micro/nano surface may be promising to repair missing teeth. Show more

Keywords: Dental implant, surface modification, porous titanium

DOI: 10.3233/JAE-171166

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1097-1102, 2019

Authors: Kang, Semin | Okuyama, Takeshi | Tanaka, Mami

Article Type: Research Article

Abstract: This study aims to elucidate the effect of surface roughness on feeling of stiffness. In order to clarify the effect of surface roughness, we focus on the fingertip motion during the sensory evaluation of stiffness feeling. In this paper, the pair comparison method was used in sensory evaluation with two kinds of instruction. One is that subjects evaluated stiffness of samples freely. The other is that subjects evaluated them with feeling the surface roughness. During the sensory evaluation, subject’s fingertip trajectories and contact force with the samples were measured. From the results of sensory evaluation, it was found that surface …roughness obviously affected feeling of stiffness in the case of instruction that subjects evaluated them with feeling the surface roughness. Show more

Keywords: Tactile sensation, stiffness, roughness, sensory evaluation, pair comparison method

DOI: 10.3233/JAE-171028

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1103-1110, 2019

Authors: Watanabe, Keisuke | Abe, Takao | Isozaki, Goushiro | Okuyama, Takeshi | Tanaka, Mami

Article Type: Research Article

Abstract: Monitoring of scratching motion accompanied with itch is important for the medical treatment of skin diseases. Although there were some studies on monitoring scratching motion, the mechanical characteristics of scratching have not been researched enough. Therefore, in this paper, we developed an estimation method of human scratching motion characteristics, especially contact force. In experiment, we measured motions of scratching weakly and strongly against artificial skin placed on three-axis force sensor. Displacement of artificial skin and fingertip trajectory were analyzed by using three-dimensional motion measurement system and compared with contact force measured by the force sensor. In addition, an analysis of …scratching motion against human skin by using the developed system was conducted too. From these results, we confirmed that measuring skin displacement of skin surface and fingertip trajectory are effective for the estimation of the mechanical characteristics of scratching. Show more

Keywords: Scratching, motion analysis, itch, skin damage, artificial skin

DOI: 10.3233/JAE-171181

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1111-1118, 2019

Authors: Okuyama, Takeshi | Kobayashi, Kouhei | Tanaka, Mami

Article Type: Research Article

Abstract: In this paper, a novel wearable sensor to estimate the force applied at fingertip is developed. To perform rehabilitation of fingers effectively, it is important to measure finger force of patients without inhibiting grip sensation. Therefore, we focused on the relationship between tension of tendon and fingertip force, and proposed a ring type sensor to estimate the fingertip force from tension of tendon. First, the ring type sensor is fabricated. And we investigate the relationship between sensor output and fingertip force by experiments. From the results, it was found that the sensor output is related to the fingertip force. And …we obtained a relational expression to calculate fingertip force from sensor output. Next, estimation experiment of fingertip force was conducted. It was confirmed that the developed sensor system is available to estimate the fingertip force without placing the sensor on the fingertip. Show more

Keywords: Fingertip force, tendon, tension, wearable sensor

DOI: 10.3233/JAE-171143

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1119-1126, 2019

Authors: Saito, Sho | Okuyama, Takeshi | Tanaka, Mami

Article Type: Research Article

Abstract: Elucidating causes of infertility is important to conduct proper treatment for infertility. Mechanical characteristics of the endometrium may be mentioned as a cause of infertility. In this paper, we focus on softness of the endometrium. As a fundamental research for the softness measurement of the endometrium, we developed a system for measuring softness of cylindrical objects by using a balloon catheter. The measurement system is composed of a balloon catheter, a syringe and a pressure sensor. Young’s modulus of cylindrical objects is calculated from balloon radius and internal pressure when the balloon is expanded in the object. In the experiment, …we prepared four kinds of cylindrical samples with different softness. By using the measurement system, Young’s modulus of each cylindrical sample is estimated. And the estimated values are compared with Young’s modulus measured by compression test. From the results, it was found that the developed system is effective for measuring softness of cylindrical objects. Show more

Keywords: Balloon catheter, young’s modulus, measurement, softness

DOI: 10.3233/JAE-171135

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1127-1134, 2019

Authors: Wang, Minghui | Yu, Hongliu

Article Type: Research Article

Abstract: Fecal incontinence caused by sphincter dysfunction is a difficult medical problem which has not been fully resolved. An artificial anal sphincter (AAS) is considered an eventual choice as prosthesis to maintain anal continence. Currently, Acticon Neosphincter, the only device certified by the US Food and Drug Administration can not maintain the long-term effectiveness. The crucial problem of this study was to keeping long-term biomechanical compatibility between the AAS and the surrounding tissue. This paper presented a design of an AAS with constant force or pressure using superelastic shape memory alloy (SMA) to solve the problem. A C-shaped superelastic SMA sheet …was optimized to obtain constant force or pressure by combing finite element analysis with ANSYS and genetic algorithm in MATLAB. The result of optimization was validated by performing an experiment. The optimized model was embedding into the device to realize clamping the soft tissue with constant force, which was confirmed by experiments. Show more

Keywords: Artificial anal sphincter, constant force, superelasticity

DOI: 10.3233/JAE-171065

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1135-1141, 2019

Authors: Liu, Xiaojun | Umemoto, Takafumi | Kato, Hideaki | Narita, Takayoshi | Moriyama, Hiroyuki

Article Type: Research Article

Abstract: Ultra-compact electric vehicles are becoming popular means of personal mobility. However, due to their small size, it is difficult to install an assist mechanism for steering operation in most of these vehicles. As a solution, the research team proposes the application of the steer-by-wire system (SBWS) to control the front tires of the vehicle without any mechanical connection. By changing the steering gear ratio and steering wheel reaction torque, SBWS can provide optimal operability and driving comfort. In this study, an experimental vehicle is equipped with SBWS and the steering reaction torque of the steering wheel based on the steering …angle as feedback is adjusted. The experimental results show that changing the steering wheel reaction torque affects driver muscle burden. Show more

Keywords: Muscle burden, ultra-compact electric vehicle, steer-by-wire system, reaction torque

DOI: 10.3233/JAE-171254

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1143-1151, 2019

Authors: Song, Siyang | Xu, Minglong | Sheng, Hao | Shao, Shubao | Zheng, Junyi | Zhu, Xueyu

Article Type: Research Article

Abstract: This paper introduces a new flexible capacitive force sensor for cardiopulmonary resuscitation (CPR) to evaluate the quality of chest compression (CC). Compared with other feedback devices, this sensing element is flexible, which helps avoid the risk of tissue injury to the patient. We describe the relationship between the compressive force and the capacitance of the sensor element, and design a circuit to transduce the capacitance into a voltage. Finally, we tested the system during CPR training with a manikin. The experiment shows that the sensing element can help rescuers distinguish between effective and ineffective CC due to inadequate compression rate …and/or depth. Show more

Keywords: Capacitance Force Sensor, cardiopulmonary resuscitation, flexible

DOI: 10.3233/JAE-171082

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1153-1160, 2019

Authors: Mihalache, Ovidiu | Yamaguchi, Toshihiko | Shirahama, Takuma | Ueda, Masashi

Article Type: Research Article

Abstract: The paper presents the application of window multi-frequency (WMF) algorithms using eddy currents (EC) to the in-service inspection of fast breeder reactor (FBR) steam generator (SG) tubes in the presence or absence of sodium. Detection of defects filled with sodium were investigated based on three dimensional finite element simulations, using an in-house developed code, of remote field eddy current (RFEC) multi-coil sensors system. WMF algorithms, previously confirmed using 3D FEM simulations, are validated for the first time in the paper for multi-coil RFEC systems with either experimental measurements or mixed simulations-measurements from defects near tube support plate (SP) of FBR …before and after sodium draining. The efficient suppression of combined sodium and SP signal is acquired through the use of WMF to enhance the signal/noise ratio (between 6 and 9) for detection of partial (up to 30% depth from tube wall thickness) or full circumferential (20% depth) outer tube defects. Show more

Keywords: FBR, steam generator, multi-frequency, sodium, remote field eddy currents, finite element

DOI: 10.3233/JAE-171237

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1161-1168, 2019

Authors: Cheng, Weiying

Article Type: Research Article

Abstract: In the measurement of a metallic plate’s dimension by eddy current testing, the plate’s electrical conductivity is required but practically unavailable. This study investigated the application of swept-frequency eddy current testing (SFECT) to measure the thicknesses of the plate and a nonconductive coating over it, even without knowing the plate’s conductivity. Hinted by the known analytical expressions available for the calculation of the impedance of an air-cored coil above a plate, we found that the maximum phase angle of the normalized SFECT signal is relevant to the thickness of a conductive plate and the liftoff, regardless of the conductivity, and …can be applied to thickness measurement. Analytical and experimental studies also showed that the conductivity of a nonmagnetic plate can be measured nondestructively by using SFECT signals in the high frequency range. Show more

Keywords: Swept-frequency eddy current testing, nonmagnetic, conductivity, thickness, coating layer

DOI: 10.3233/JAE-171129

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 3, pp. 1169-1178, 2019