We use the three-dimensional linear theory of elasticity to analyse the steady state vibrations of a simply supported rectangular linear elastic laminated plate with embedded PZT layers. Some of these PZT layers act as actuators while the remaining act as sensors. It is assumed that there is perfect bonding between different layers. Numerical results for a thin and a thick plate containing one ...

Background: Ankle arthrodesis is the gold standard and most commonly used method for the treatment of post-traumatic ankle arthritis. Aims: This study is to investigate the biomechanical safety and stability of four ankle fusion models through three-dimensional finite element analysis. Methods: Four ankle fusion models were established, including anterior plate ankle fusion model, lateral plate...

Current finite-element (FE) models of the eardrum are limited to low pressures because of the assumption of linearity. Our objective is to investigate the effects of geometric nonlinearity in FE models of the cat eardrum with an approximately immobile malleus for pressures up to +/-2.2 kPa, which are within the range of pressures used in clinical tympanometry. Displacements computed with nonlin...

BACKGROUND Breast implant displacement or rupture can cause aesthetic problems and serious medical complications. Activities with prone positioning and loading of the anterior chest wall, such as massage, chiropractic or osteopathic therapies may increase the risk of implant failure and can also cause discomfort in women with natural breast tissue. Here we test the effectiveness of a newly deve...

Structural topology optimization problems have been traditionally stated and solved by means of maximum stiffness formulations. On the other hand, some effort has been devoted to stating and solving this kind of problems by means of minimum weight formulations with stress (and/or displacement) constraints. It seems clear that the latter approach is closer to the engineering point of view, but i...

OBJECTIVE The aim of this study was to evaluate the multisegmental static postural balance of active eutrophic and obese elderly women using a three-dimensional system under different sensory conditions. METHODS A cross-sectional study was conducted on 31 elderly women (16 eutrophic and 15 obese) aged 65 to 75 years. The following anthropometric measurements were obtained: weight, height, wai...

We evaluated the biomechanical properties of two different methods of fixation for unstable fractures of the proximal humerus. Biomechanical testing of the two groups, locking plate alone (LP), and locking plate with a fibular strut graft (LPSG), was performed using seven pairs of human cadaveric humeri. Cyclical loads between 10 N and 80 N at 5 Hz were applied for 1,000,000 cycles. Immediately...

When a random spatial noise pattern is displaced for a short distance it seems to move coherently, but when the displacement exceeds a certain value, the direction of motion cannot be clearly perceived. We measured the displacement limit (Dmax) for a two-frame sequence and found that it depended on the size of the elements comprising the random pattern, even when low spatial frequencies were re...

An isometer, a highly compliant spring-scale device for measuring suture displacement, has been used intraoperatively by surgeons to select the optimal placement of the femoral tunnel for an anterior cruciate ligament graft. The isometer measures the displacement of a suture centered in a tibial tunnel and attached to an intraarticular location on the femur before the femoral tunnel is drilled....

OBJECTIVE The aim of this study was to determine the optimal loading conditions for pure intrusion of the six maxillary anterior teeth with miniscrews according to alveolar bone loss. METHODS A three-dimensional finite element model was created for a segment of the six anterior teeth, and the positions of the miniscrews and hooks were varied after setting the alveolar bone loss to 0, 2, or 4 ...