Keywords

Paper information

Timothy DAVID and Masao TANAKA, “Preface”, Journal of Biomechanical Science and Engineering, Vol. 5, No. 1 (2010), pp.1-1 . doi:10.1299/jbse.5.1

Titanium dental implants (screws) are commonly used to replace missing teeth by forming a biological union with bone ("osseointegration"). Micro-computerised tomography (?CT) may be useful for measuring bone mineral density around dental implants. Major issues arise because of various artefacts that occur with polychromatic X-rays associated bench type instruments that may compromise interpretation of the observations. In this study various approaches to minimise artefacts such as; beam hardening, filtering and edge effects are explored with a homogeneous polymeric material, Teflon, with and without an implant present. The implications of the limitations of using such polychromatic ?CT systems to quantify bone mineral density adjacent to the implant are discussed.

Keywords

Dental Implants, Artefacts, Computerised Tomography

Paper information

Chae PARK, Michael SWAIN and Warwick DUNCAN, “Micro-computerised Tomography Optimisation for the Measurement of Bone Mineral Density around Titanium Dental Implants”, Journal of Biomechanical Science and Engineering, Vol. 5, No. 1 (2010), pp.2-10 . doi:10.1299/jbse.5.2

Vascular diseases, such as ischemic heart disease, infarction, aneurysms, stroke and stenosis are a leading cause of serious long-term disability and their mortality rate is as high as that of cancers in many countries. Recently, neurovascular intervention using catheters is a minimally-invasive endovascular technique used to treat vascular disease of the brain, and a navigation system for catheters has been developed to facilitate surgical planning and to provide intra-operative assistance. Since the mechanical properties of a catheter play an important role in reaching the targeted disease, tracking of catheter movement during endovascular treatment may be useful to increase confirmation of the rate of successful operation. In this study, we developed an in vitro tracking system for catheter motion using poly (vinyl alcohol) hydrogel (PVA-H) to mimic an arterial wall. The employed models were made of PVA-H, which is sufficiently transparent to permit observation of catheter movement in the artery. This system is expected to contribute to validation of computer-based navigation systems for surgical assistance.

Keywords

Endovascular Treatment, Catheter Motion, Tracking System, Poly (vinyl alcohol) Hydrogel, Biomodel

Paper information

ChangHo YU, Hiroyuki KOSUKEGAWA, Keisuke MAMADA, Kanju KUROKI, Kazuto TAKASHIMA, Kiyoshi YOSHINAKA and Makoto OHTA, “Development of an In Vitro Tracking System with Poly (vinyl alcohol) Hydrogel for Catheter Motion”, Journal of Biomechanical Science and Engineering, Vol. 5, No. 1 (2010), pp.11-17 . doi:10.1299/jbse.5.11

The purpose of this study was to reproduce the force in a voluntary contraction via surface electromyography (SEMG) using a systematic muscle model. We measured the isometric voluntary contractile force and SEMG of the human biceps. We examined the effect of the electrode size on SEMG. A pair of electrodes with a diameter of 1 mm was adopted, because they avoided signal interference from the action potentials of other motor units. We added a converter to the muscle model to obtain an artificial action potential that successively drives an excitation-contraction controller and a motor unit. When the force was less than 30% of the maximum force, EMG signals were obtained from a few motor units. The resultant force coincided well with the experimentally observed force with an accuracy of around 90% when an appropriate threshold level was set up in the converter. This method will increase in performance when we can separately detect the SEMG signals from multipoint measurements.

Keywords

Muscle, Model, Electromyography, Numerical Simulation, Excitation-Contraction Coupling

Paper information

Akira ITO, Masami SAITO and Youjiro TAMURA, “Simulation of Force Changes in the Human Biceps Using a Muscle Model Based on Electromyographic Signals”, Journal of Biomechanical Science and Engineering, Vol. 5, No. 1 (2010), pp.18-23 . doi:10.1299/jbse.5.18

The success of total hip arthroplasty (THA) in improving joint function and reducing pain is regarded as one of the great achievements of modern medicine. Today, most femoral stems with cementless fixation are made of either cobalt-chrome-molybdenum (CoCrMb) or titanium-aluminum-vanadium (TiAlV) alloys. In order to obtain adequate initial stability of the cementless femoral stem, the implant must be placed in contact with bone of sufficient strength to support the prosthesis rigidly. This study introduces a unique approach in this research category, making use of shape memory alloys (SMA) for cementless stems to obtain adequate initial stability. Using SMA that exhibits a shape memory effect, better proximal fit and fill with smooth insertion will be accomplished. In this study, numerical evaluation is intended with initial stability of a cementless stem for which SMA is utilized. A result of the numerical analysis reveals that use of SMA is found to be effective enough to obtain rigid initial stability.

Keywords

Total Hip Arthroplasty (THA), Computational Biomechanics, Shape Memory Alloy (SMA), Finite Element Analysis, Cementless Stem, Implant Fixation

Paper information

Masaru HIGA, Takuya TSUCHIHASHI, Masayoshi ABO and Satoshi KAKUNAI, “Possibility of Total Hip Arthroplasty Using Shape Memory Alloy”, Journal of Biomechanical Science and Engineering, Vol. 5, No. 1 (2010), pp.24-31 . doi:10.1299/jbse.5.24

An auditory brain-computer interface (BCI) which detects event-related potentials (ERPs) elicited by selective attention to one of the tone streams was proposed. Two frequency oddball tone sequences with different tone frequency ranges were alternately presented to subjects, and were perceived by subjects as two kinds of segregated streams. Event-related potentials elicited by two kinds of deviant tones were classified by linear discriminant analysis (LDA) to find the stream subjects paid selective attention to. Experiments with six subjects have shown that this system could realize binary selection from two tone streams.

Keywords

brain-computer interface (BCI), selective attention, event-related potential, auditory stream segregation, pattern classification

Paper information

Shin'ichiro KANOH, Ko-ichiro MIYAMOTO and Tatsuo YOSHINOBU, “A Brain-Computer Interface (BCI) System Based on Auditory Stream Segregation”, Journal of Biomechanical Science and Engineering, Vol. 5, No. 1 (2010), pp.32-40 . doi:10.1299/jbse.5.32

Biomimetic robots have received more and more attention, as people try to learn from nature in which exist amazing and uniquely evolved mechanisms shown by very species. Fleas, as such one example, are best jumper of all known animals in the world, considering their body size. It can jump about 150 to 200 times its own body length. This paper reports on modeling and simulation of jumping mechanism of a biomimetic robot and provides a guide line for designing and modeling the biomimetic robot that can mimic fleas to jump very high length with respect to its body length.

Keywords

Robotics, Biomechanics, Resilin, Femur, Trochanter, Coxa, Control, Modeling, Simulation

Paper information

Sheikh Rashed BUKSH, XiaoQi CHEN and Wenhui WANG, “Study of Flea Jumping Mechanism for Biomimetic Robot Design”, Journal of Biomechanical Science and Engineering, Vol. 5, No. 1 (2010), pp.41-52 . doi:10.1299/jbse.5.41