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VIDEO TRACKING DEVICE For gait analysis
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What this project aimed to produce is a tool which will enable professionals to analyse an individuals walking style in a way not used before. There have been many qualitative and quantitative inventions to enhance gait analysis since the early 1800's. Complicated stills cameras, interrupted light techniques, inserted pins, motion film, force plates, pneumatic shoes, glass walkways and electromyographs have all been used, and many more. This project is using a video technique for qualitatively recording an individuals gait during a sequence of step cycles.
Film and video have certainly been used before, for decades in fact. Commonly the camera (film or video) is static and views a length of a walkway, and records the cycles of gait as the person walks from one extreme of view to the other. Often one or more markers are placed on the body so that the points may be recorded by computer (automatically or by an operator), which may then produce a wireframe simulation of the locomotion, along with various statistics. Nowadays this is almost standard in any well equipped gait laboratory. There have been some apparatus which have had cameras mounted on trolleys and been pushed by hand to follow and film a subject on a walkway.
This project aimed to combine these last two methods to produce a device which will use a marker as a defining point to follow. That is, the device will aim to keep the marker laterally in the middle of the video image at all times. Instead of just following the person at walking pace and filming the lower body the instrument conceptually will allow the study of a particular piece of anatomy. For example the camera may film a close up of the knee (which therefore is where the marker would be placed) in action, or the ankle, or a suspect prosthetic component in a fitted artificial limb. The most important improvement that will be gained is increased resolution. If the example of the knee is continued; the knee would still be visible with a static camera, and with the dolly mounted version, but the camera's frame of reference makes close and detailed examination of the joint difficult. Ideally with this new device the joint in question will appear almost laterally static on the video screen, allowing professionals to observe motion in a more convenient form. The objective of the project is not to provide quantitative information, but rather to improve the clinicians subjective viewpoint of the patient. This qualitative information cannot be measured to rate its success, but feedback from professionals should give an indication of the usefulness of this equipment.
