A mechanical study investigating the use of two different methods (grub and bolt screws) to secure external fixation half pins to circular frames. A four part experiment: (1) Grub and bolt screws were used to secure half pins in Taylor Spatial frames. Loosening torques were measured using a calibrated torque wrench. (2) Using universal testing machine (UTM), axial loading was applied to establi...

In cementless total hip arthroplasty, the rotational stability of stem is generally confirmed in a one-time manual evaluation by surgeon. This study was performed to evaluate sequential intraoperative changes using torque wrench. Primary arthroplasty on 52 consecutive hips single wedge design. Intraoperative uniformly Evaluations were immediately after broach insertion and before final (after p...

Motion planning in multi-contact scenarios has recently gathered interest within the legged robotics community, however actuator force/torque limits are rarely considered. We believe that these limits gain paramount importance when the complexity of the terrains to be traversed increases. For this reason we propose two new six-dimensional bounded polytopes named the Actuation Wrench Polytope (A...

We describe an apparatus that can measure the instantaneous angular displacement and torque applied to a quartz particle which is angularly trapped. Torque is measured by detecting the change in angular momentum of the transmitted trap beam. The rotational Brownian motion of the trapped particle and its power spectral density are used to determine the angular trap stiffness. The apparatus featu...

PURPOSE The objective of this study was to compare torques applied by new and used manual torque devices for Morse-taper implants. MATERIAL AND METHODS Fifteen ITI manual torque devices were tested. Those in group 1 (n = 5) were new (ie, never used), those in group 2 (n = 5) had been used 50 to 200 times, and those in group 3 (n = 5) had been used 500 to 1,000 times. The torques applied by ea...

Purpose: The aims of the present study are to correlate the ISQ values, registered by the Osstell ISQ system, with the insertion torque during the placement of the implant, and to assess the influence of the thread initiator on the ISQ values and on the insertion torque. Materials and methods: 140 rough surface implants screw-shaped implants, placed in 10 bovine ribs, were assigned to Group A (...

The vibration characteristics of bolted structures are crucially affected by the pre-tightening torque. An approach for identifying torque dependent stiffness parameters joints is proposed in this paper. Firstly, interface joint characterized thin layer element with isotropic material property, and parameter value property assigned relative to distance from center bolt; influence bolt ignored. ...

Joint friction is a major problem in accurately controlling robot position during manipulator tasks involving small and slow motions. Previous research in this field suggests the use of either complex modeling and identification techniques, or expensive and delicate torque sensors that must be integrated into the manipulator. This paper proposes a simple, cost-effective method for compensating ...

ABSTRACT In order to evaluate the effect of countersinking on dental implants primary stability installed in low density bones, thirty dental implants were installed in the most proximal region of oxen ribs and grouped as follow: Group1: Fifteen implants installed by standard drilling with countersinking, Group2: Fifteen implants installed by standard drilling without countersinking. The gradua...