The application of physiological loading using a dynamic, multi-axis spine simulator
Holsgrove, TP; Miles, AW; Gheduzzi, S
Date: 30 December 2016
Journal
Medical Engineering and Physics
Publisher
Elsevier
Publisher DOI
Abstract
In-vitro testing protocols used for spine studies should replicate the in-vivo load environment as closely as possible. Unconstrained moments are regularly employed to test spinal specimens in-vitro, but applying such loads dynamically using an active six-axis testing system remains a challenge. The aim of this study was to assess the ...
In-vitro testing protocols used for spine studies should replicate the in-vivo load environment as closely as possible. Unconstrained moments are regularly employed to test spinal specimens in-vitro, but applying such loads dynamically using an active six-axis testing system remains a challenge. The aim of this study was to assess the capability of a custom-developed spine simulator to apply dynamic unconstrained moments with an axial preload.Flexion-extension, lateral bending, and axial rotation were applied to an L5/L6 porcine specimen at 0.1 and 0.3. Hz. Non-principal moments and shear forces were minimized using load control. A 500. N axial load was applied prior to tests, and held stationary during testing to assess the effect of rotational motion on axial load.Non-principal loads were minimized to within the load cell noise-floor at 0.1. Hz, and within two-times the load-cell noise-floor in all but two cases at 0.3. Hz. The adoption of position control in axial compression-extension resulted in axial loads with qualitative similarities to in-vivo data.This study successfully applied dynamic, unconstrained moments with a physiological preload using a six-axis control system. Future studies will investigate the application of dynamic load vectors, multi-segment specimens, and assess the effect of injury and degeneration.
Engineering
Faculty of Environment, Science and Economy
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