Direct drive motors became very popular due to the simple mechanical structure that avoids the use of a speed reducer that can cause position errors and instability. With the use of a direct drive motor, undesired backlash, and flexibility are reduced significantly. However, since load variation is linked to the motor axis directly, an advanced algorithm has to be applied in the motion control ...

OBJECTIVE To assess the hydrodynamic properties of three new types of hydrocephalus valve. METHODS Three new constructions have been recently tested in the UK shunt Evaluation Laboratory: the magnetically adjustable Strata Valve (Medtronic PS Medical), the gravitational Miethke Dual-Switch Valve (Aesculap) and the ventriculo-sinus SinuShunt (CSF Dynamics). Pressure-flow performance curves wer...

A 58-year-old woman presented with recent history of fever. She had history of prosthetic aortic and mitral valve implanted four years ago. Blood cultures were negative and transesophageal echocardiography (TEE) detected a large mass within the mitral prosthesis (Fig. 1a, Video 1). After seven days under antibiotherapy, repeated TEE revealed rapidly growing giant vegetation within the valve lea...

Seventy-four patients with single prosthetic valves (Björk-Shiley or Starr-Edwards) in the mitral or aortic position and 18 controls with rheumatic valvar heart disease were investigated for evidence of intravascular haemolysis. Serum lactate dehydrogenase (LDH) was used as the most sensitive indicator of haemolysis. Raised concentrations were found in a third of 39 patients with Björk-Shiley p...

Rolling bearings have to meet the highest requirements in terms of guidance accuracy, energy efficiency, and dynamics. An important factor influencing these performance criteria is cage, which has different effects on bearing dynamics depending cage’s geometry load. Dynamics simulations can be used calculate cage dynamics, exhibit high agreement with real motion, but are time-consuming complex....

INTRODUCTION Transforaminal lumbar interbody fusion is a popular procedure used to achieve spondylodesis in patients with degenerative lumbar spinal diseases. We present a rare case of a patient with a set screw fracture with cage dislocation after an open transforaminal lumbar interbody fusion procedure. To the best of our knowledge, this case is the first of its kind to be reported. CASE PR...

Both stocking rate and housing systems are main factors influencing the occurrence of feather pecking in laying hens raised in conventional cage system. This study examines the effects of different type of cage and stock density on feather pecking behaviour in hens. Total of 216 Hisex Brown hens at 16 weeks of age were randomly selected and put into 2 types of battery cages: conventional cages ...

BACKGROUND A free-floating ball thrombus in the left atrium is a rare clinical condition. However, the diagnosis of this condition has been facilitated by the advent and development of echocardiography and multi-detector row computed tomography (MDCT) and several cases have been reported. CASE REPORT We report a case of a 75-year-old woman who had recurrent giant spherical thrombi in the left a...