The spiral orientation of left ventricular (LV) fibers suggests that twisting about the ventricular long axis of the apex with respect to the base, i.e., torsional deformation, may be characteristic of LV contraction. To demonstrate this twisting motion, 10 orthotopic human cardiac allograft recipients were studied with biplane cineradiography of tantalum helices implanted within the LV midwall...

OBJECTIVE To investigate the biomechanical properties of the percutaneous compression plating system for intertrochanteric hip fractures. DESIGN A biomechanical laboratory investigation on human cadaveric upper femora was conducted. SETTING Biomechanical laboratory. PATIENTS Sixteen femora from cadavers of patients aged 60 to 85 years. INTERVENTION An intertrochanteric fracture was perf...

INTRODUCTION: Intervertebral disc experiences large complex deformations including compression, rotation, and bending under daily activity. For example, twisting while carrying a weight, loads the disc under axial compression and axial rotation. Previous work showed that the rate of degeneration and disc injury is higher for in workers that experience repetitive twisting and lifting [1]. Disc d...

Both medial and anterolateral plate applications have been described for the treatment of distal tibia fractures, each with distinct advantages and disadvantages. The objective of this study was to compare the biomechanical properties of medial and anterolateral plating constructs used to stabilize simulated varus and valgus fracture patterns of the distal tibia. In 16 synthetic tibia models, a...

BACKGROUND AND PURPOSE Removal of distal cement at femoral implant revision is technically challenging and is associated with complications such as cortical perforations. A technique that can reduce the risks and operating time is to make a small cortical window in the distal femur for enhanced access. We wanted to determine whether the use of long, bridging, cemented femoral stems is necessary...

Introduction. Torsional vibrations caused by drilling using a polycrystalline diamond compact (PDC) bit are analysed wellbore data obtained under various modes. The torsional analysed. Two types of vibrations, including those the cutting action and frictional forces. Aim. To investigate induction as result rock destruction PDC bits. Materials methods. research methodology was based on “Richard-...

This paper presents three-dimensional static modeling of the human lumbar spine to be used in the formation of anatomically-correct movement patterns for a fully cable-actuated robotic lumbar spine which can mimic in vivo human lumbar spine movements to provide better hands-on training for medical students. The mathematical model incorporates five lumbar vertebrae between the first lumbar verte...

9 This paper presents three-dimensional static modeling of the 10 human lumbar spine to be used in the formation of anatomically11 correct movement patterns for a fully cable-actuated robotic 12 lumbar spine which can mimic in vivo human lumbar spine move13 ments to provide better hands-on training for medical students. 14 The mathematical model incorporates five lumbar vertebrae 15 between the...

existence of cracks in industrial structures is one of the important causes of their failure, especially when they are subjected to important axial compressive forces that might lead to buckling. therefore, it must be considered in stress analysis and designing and loading of such structures. in this paper, the buckling and post-buckling behaviors of stainless-steel cracked plates under axial c...

Rotor dynamics plays an important role in many engineering fields such as gas turbine, steam turbine, reciprocating and centrifugal compressors, the spindle of machine tools, and so on. Owing to the growing demands for high power, high speed, and light weight of the rotor-bearing system, computations of critical speeds and steady-state response at synchronous and sub critical resonances become ...