Study On The Construction Of The Spinal Biomechanical Test System And The Reliability Based On Labview And Six-axis Robot

Objective: To build spinal biomechanics test system in vitro based on upper computer,six-axis robot,six-degree-of-freedom force/torque sensor and to complete test programming based on Lab VIEW and a preliminary reliability test.Methods: To select and purchase hardware facilities and to design and draw various fixtures and other supporting facilities with CAD software;To complete programming by the software Lab VIEW.With the method of Ethernet and Profibus communication,to realize real-time communication between the upper machine and robot,and to realize translational motion and flexion,left and right lateral flexion,rotation in the six direction of up,down,left,right,front and back.And to realize displacement control and load control and be able to read the terminal robot position,rotation angle and the force/torque value.To complete data acquisition,displaying,processing,storage,and other functions through the data acquisition card and upper computer.To firmly fix the digital dial gauge to the end of the robot through the special fixture so that the movement direction of dial gauge measuring rod and robot is parallel or perpendicular,thus reducing the measurement error.To drive the robot to finish six direction translational motion of up,down,left,right,front and back using Lab VIEW control program.After the completion of each action,to record data,then to reset the robot,to set dial gauge to zero and start the next set of tests.To repeat each group action 10 times.After the completion of the testing,to arrange all the data and start statistical analysis,so that to obtain the precision and accurate value of the test system value and an analyse the causes of possible error.To complete the test of flexion,lateral flexion and rotation to the anti-damping specimens using the platform.To draw the corresponding load-displacement curve and analyse the data and debug the test system so that it can stably finish the experiment tasks.To complete the flexion,lateral flexion and rotation test to the sheep spine specimen,draw the corresponding load-displacement curve.And to compare with the formal literature data and draw the conclusion of that the experimental results,to verify the reliability of the biomechanical platform.Results: To have developed and set of high precision test system in vitro based on Lab VIEW and six-axis robot with the average translational precision of 0.0081 mm and the average translational accuracy of 0.0567 mm.To have compiled the robot motion control program and data acquisition,displaying,processing,storage procedures.To have been able to load the test specimens with high preciseness with the method of load/displacement,to effectively simulate the various degrees of freedom movement of the spine,and to record the change of the position and force of spine functional unit in real time.The anti-damping specimen and the biomechanical testing of the sheep spine were completed to verify that the platform could preliminarily meet the requirements of various spinal biomechanical tests.Conclusion: The spinal biomechanical testing system in vitro of based on Lab VIEW and six-axis robot can successfully complete the biomechanical test of the spine,and its precision meets the requirements of regular testing.