Knowledge of local bone quality is essential for surgeons to determine operation techniques. A device for intraoperative measurement of local bone quality has been developed by the AO-Research Foundation (Densi - Probe®). We used this device to experimentally measure peak breakaway torque of trabecular bone in the proximal femur and correlated this with local bone mineral density (BMD) and fail...

Upon remodeling of the ventricle after a provoking stimulus, such as hypertension, connections between adjacent myocytes may need to be "reformatted" to preserve a synchronization of excitation of the remodeling heart. In the mammalian heart, the protein connexin forms the gap junctions that allow electrical and chemical signaling communication between neighboring cells. We aim to elucidate whe...

Although humans clearly expend more energy to walk with an extra load, it is unclear what biomechanical mechanisms contribute to that increase. One possible contribution is the mechanical work performed on the body center of mass (COM), which simple models predict should increase linearly with added mass. The work should be performed primarily by the lower extremity joints, although in unknown ...

BACKGROUND AND PURPOSE In recent years several different plate designs for internal fixation of fractures of the distal radius have been developed. However, few biomechanical studies have been performed to compare these new implants. The purpose of this study was to compare the mechanical properties of 5 different commercially available plates (3 volar and 2 dorsal) with standard K-wire fixatio...

It was recently shown that acute respiratory distress syndrome (ARDS) mortality has not been reduced in over 15 years and remains ~40 %, even with protective low tidal volume (LVt) ventilation. Thus, there is a critical need to develop novel ventilation strategies that will protect the lung and reduce ARDS mortality. Protti et al. have begun to analyze the impact of mechanical ventilation on lu...

When combined with a piezoelectric actuator, a mechanical amplifier can achieve high resolution and long range motion. In this paper, a previously proposed compliant mechanical amplifier based on a symmetric five bar structure was studied for performance optimization. The amplifier was optimized based on its most significant design parameters with goals of large amplification ratio and high nat...

We compared two sets of loading conditions for their effect on the mechanical performance of isolated rat trabecular muscle: (1) loading which approximated that of the intact ventricle; (2) nonphysiological afterloaded isotonic contractions. Improved performance, manifested by increased shortening and rate of shortening at constant load, was seen when lengthening occurred at light loads, as in ...

ST UK CONFERENCE 2006 1 1.0 INTRODUCTION Headphone modelling concerns the solution of a number of coupled problems centring on a small mechanical diaphragm vibrating in an enclosed space. Frequently, the electro-acoustic transduction mechanism is dynamic, and the transfer functions between electrical (v,i) and mechanical (F,u) quantities must be considered. These transfer functions will in part...

PURPOSE The purpose of this study was to evaluate the mechanical performance of different suture locking mechanisms including: i) interference fit between the anchor and the bone (eg, 4.5 mm PushLock, 5.5 mm SwiveLock), ii) internal locking mechanism within the anchor itself (eg, 5.5 mm SpeedScrew), or iii) a combination of interference fit and internal locking (eg, 4.5 mm MultiFIX P, 5.5 mm Mu...

tendon never restores the complete biological and mechanical properties after healing. bone marrow and recently adipose tissue have been used as the sources of mesenchymal stem cells, which have been proven to enhance tendon healing. stromal vascular fraction (svf), derived from adipose tissue by an enzymatic digestion, represents an alternative source of multipotent cells, which undergo differ...