Contact Forces Required to Record Monophasic Action Potentials: A Complement to Catheter Contact Force Measurement

2019 ◽  
Vol 66 (10) ◽  
pp. 2974-2978
Author(s):  
Megan M. Schmidt ◽  
Mark A. Benscoter ◽  
Paul A. Iaizzo
Keyword(s):  
Contact Force ◽  
Action Potentials ◽  
Force Measurement ◽  
Contact Forces ◽  
Monophasic Action Potentials

A New Low-Cost System for Tyre-Road Force Measurements: Design and Validation

2007 ◽  
Author(s):  
Francesco Braghin ◽  
Federico Cheli ◽  
Emiliano Giangiulio ◽  
Federico Mancosu
Keyword(s):  
Control Systems ◽  
Contact Force ◽  
Measurement System ◽  
Force Measurement ◽  
Low Cost ◽  
Contact Forces ◽  
Vehicle Safety ◽  
Measurement Systems ◽  
Wheel Turn ◽  
Force Measurement System

The measurement of tyre-road contact forces is the first step towards the development of new control systems for the improvement of vehicle safety and performances. At present, tyre-road contact force measurement systems are very expensive and modify the non suspended vehicle inertia due to their high mass and rotational inertia moment. Thus, vehicle dynamics is significantly affected. The measured contact forces are therefore not fully representative of the contact forces that the tyres will experience during real working conditions. A new low-cost tyre-road contact force measurement system has been developed that is installable on any type of wheel. Its working principle is based on the measurement of three deformations of the wheel. Through a dynamic calibration of the instrumented wheel it is possible to reconstruct all three contact force and torque components once per wheel turn. These forces are then sent to the vehicle chassis and may be used by on-board active control systems to improve vehicle safety and performances. Validation tests were carried out with a vehicle having all four wheels equipped with the low-cost tyre-road contact force measurement system. It was possible to reconstruct contact forces once per wheel turn in any working condition with a precision that is comparable to that of existing high-cost measurement systems ([1], [2], [3], [4], [5]).

scholarly journals Design and Calibration of a Tri-Directional Contact Force Measurement System

2021 ◽  
Vol 11 (2) ◽  
pp. 877
Author(s):  
Rizwan Ahmed ◽  
Christian Maria Firrone ◽  
Stefano Zucca
Keyword(s):  
Contact Force ◽  
Measurement System ◽  
Force Measurement ◽  
Three Dimensional ◽  
Dynamic Contact ◽  
Forced Response ◽  
Contact Forces ◽  
Blade Vibration ◽  
Contact Models ◽  
Force Measurement System

In low pressure turbine stages, adjacent blades are coupled to each other at their tip by covers, called shrouds. Three-dimensional periodic contact forces at shrouds strongly affect the blade vibration level as energy is dissipated by friction. To validate contact models developed for the prediction of nonlinear forced response of shrouded blades, direct contact force measurement during dynamic tests is mandatory. In case of shrouded blades, the existing unidirectional and bi-directional contact force measurement methods need to be improved and extended to a tri-directional measurement of shroud contact forces for a comprehensive and more reliable validation of the shroud contact models. This demands an accurate and robust measurement solution that is compatible with the nature and orientation of the contact forces at blade shrouds. This study presents a cost effective and adaptable tri-directional force measurement system to measure static and dynamic contact forces simultaneously in three directions at blade shrouds during forced response tests. The system is based on three orthogonal force transducers connected to a reference block that will eventually be put in contact with the blade shroud in the test rig. A calibration process is outlined to define a decoupling matrix and its subsequent validation is demonstrated in order to evaluate the effectiveness of the measurement system to measure the actual contact forces acting on the contact.

Touchdown Bearing Contact Forces in Magnetic Bearing Systems

2013 ◽  
Author(s):  
Fawaz Y. Saket ◽  
M. Necip Sahinkaya ◽  
Patrick S. Keogh
Keyword(s):  
Contact Force ◽  
Force Measurement ◽  
Load Capacity ◽  
Magnetic Bearing ◽  
Contact Forces ◽  
Contact Dynamics ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Operational Conditions ◽  
Contact Free

Under contact-free levitation, rotors supported by active magnetic bearings have many advantages such as allowing near frictionless rotation and high rotational speeds. They also provide the designer the capability to achieve increased machine power density. However, magnetic bearings possess limited load capacity and operate under active control. Under certain operational conditions, the load capacity may be exceeded or a transient fault may occur. The rotor may then make contact with touchdown bearings and the ensuing rotor dynamics may result in transient or sustained contact dynamics. The magnetic bearings may have the capability to restore contact-free levitation, though this will require appropriate control strategies to be devised. An understanding of the contact dynamics is required, together with the relationship between these and applied magnetic bearing control forces. This paper describes the use of a contact force measurement system to establish the force relationship. The contact force components measured by the system are calibrated against forces applied by an active magnetic bearing. The data generated can be used to validate non-linear dynamic system models and aid the design of control action to minimize or eliminate contact forces.

scholarly journals Dynamics of Multibody Systems With Spherical Clearance Joints

2005 ◽  
Author(s):  
P. Flores ◽  
J. Ambro´sio ◽  
J. C. P. Claro ◽  
H. M. Lankarani
Keyword(s):  
Contact Force ◽  
Multibody Systems ◽  
Contact Forces ◽  
Force Model ◽  
Clearance Joints ◽  
Continuous Contact ◽  
Clearance Joint ◽  
Contact Force Model ◽  
Dynamics Of Multibody Systems ◽  
The Impact

This work deals with a methodology to assess the influence of the spherical clearance joints in spatial multibody systems. The methodology is based on the Cartesian coordinates, being the dynamics of the joint elements modeled as impacting bodies and controlled by contact forces. The impacts and contacts are described by a continuous contact force model that accounts for geometric and mechanical characteristics of the contacting surfaces. The contact force is evaluated as function of the elastic pseudo-penetration between the impacting bodies, coupled with a nonlinear viscous-elastic factor representing the energy dissipation during the impact process. A spatial four bar mechanism is used as an illustrative example and some numerical results are presented, being the efficiency of the developed methodology discussed in the process of their presentation. The results obtained show that the inclusion of clearance joints in the modelization of spatial multibody systems significantly influences the prediction of components’ position and drastically increases the peaks in acceleration and reaction moments at the joints. Moreover, the system’s response clearly tends to be nonperiodic when a clearance joint is included in the simulation.

Effects of aprindine on monophasic action potentials

1991 ◽  
Vol 24 (2) ◽  
pp. 113-120
Author(s):  
Kazuo Matsumoto ◽  
Yutaka Dohi ◽  
Yukio Asano ◽  
Keiko Kaneko
Keyword(s):  
Action Potentials ◽  
Monophasic Action Potentials
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