Study Of The System For In Vitro Stability Testing Of Spine Based On LabVIEW

As an important support and load structure of human body, spine has become animportant research content of clinicians and researchers. A precisely, quantitativelydescription of the dimensional stability of the spinal motion has an extremely importantsignificance for understanding the mechanism of the occurrence of the spinal injury anddiseases thereby determining a reasonable treatment method. It is also important for thecorrect assessment of the impact of the surgery and implants for spinal movementbehavior. However, as a flexible load body, the movement of the spine is complex anddiverse, which brought a lot of difficulties to test the biomechanical stabilities of spine.This also indirectly led to a complex structure and single software function of thetraditional measuring system. To solve these problems, the author developed the testingsystems which are economic and giving a real and accurate reflection of the movementof the spine in the physiological state. With the development tool of LabVIEW, it iscapable of measuring the strain and range of motion of spine. In order to verify theeffectiveness of the systems, a series of experiments were conducted. In this study, themain contents include the following two parts:â‘ A strain measurement system was design by a set of sensors, a special fixture,material testing machine, microcontroller. The system was able to simulate themovement of the lateral bending, flexion, extension, axial compression, and record load,displacement, strain and other information. Development of data acquisition modulebased on the LabVIEW platform was used to control the process of data acquisition.Data integration module integrated strain signal measured by the sensors and load,displacement data recorded by testing machine. It also output the strain and stiffnessdata which directly reflects the stability characteristic of the spine. Five T12-L2segments of human spine specimens were tested by using the system, and the accurateand reliable data were gained.â‘¡A ROM measurement system for testing the stability of the spine wereconstituted by a video camera, special fixtures, material testing machine, PC machine.The system was able to implement the loading of lateral bending, flexion, extension,and rotation. The marking needles were inserted into the target vertebral bodies beforethe experiment. LabVIEW and image processing technology were used to extract theregion of interest (Region of Interest, ROI) from the original image. Then, the software based on LabVIEW conducted image enhancement, morphological operations and othersteps to extract the angle of the marking needles. Six human T7-T10segments wereused for experiments. The load directions of left\right lateral bending, flexion,extension, Shun\counterclockwise reverse were implemented by the system. The angleinformation of marker pins on T8, T9vertebras were measured. Ultimately, the ROM ofT8-T9segment showed a linear increase from1Nm to5Nm, which is in line withprevious studies.In summary, the paper designed the measurement systems for spinal stabilityproperties. The structure of the systems was simple and workable, especially thesoftware part had the friendly interface and complete functions. It made up past systemswhich require complex software for the collection and analysis of data. Therefore, thesystems described here provided a new method for biomechanics measurement in spinalstability tests. It provides a reliable tool for orthopedic surgeons and researchers toevaluate of the spine diseases, injury and surgical methods.