Case Study: Polhemus Tracking System Used in Biomechanics Research

Skill Technologies' client base was primarily research oriented so it was critical they had the advantage of true real-time motion analysis. Polhemus FASTRAK enabled this with the ability to accurately compute the position and orientation of a tiny receiver as it moves through space.

Polhemus FASTRAK real-time motion analysis. Advanced Motion Measurement LLC, formerly known as Skill Technologies, was founded in 1991, developing innovative real-time, 6 Degree-Of-Freedom (6DOF) motion analysis systems. Skill's product family includes 6D-RESEARCH™, 3D-SPINE™ and 3D-GOLF™ which are utilized by companies around the world for research, clinical, sports analysis and teaching purposes.

The Need for Motion Capture

As an Olympic gymnast for Australia in both the Montreal and Moscow games, Phillip Cheetham knew first-hand about human motion and its effects on the body as a whole. Also, as former head of engineering for the U.S. Olympic Committee Sports Sciences Program and former Chairman and co-founder of a leading video motion measurement company, he had the background necessary to see the importance and need for a generalized true real-time motion analysis system. In 1991, Phillip Cheetham and his brother Stephen, started Skill Technologies with the mission to provide the most innovative biomechanics and motion analysis systems on the market.

In the early 90's, the Cheethams were relying on video analysis to work with their biomechanics and motion analysis systems. In researching ways to more fully utilize 6DOF motion tracking, the Cheethams realized that a real-time electromagnetic solution would significantly enhance their software products.

"We have had a lot of experience with video motion analysis companies," stated Stephen Cheetham. "We consider video technology to be old technology in comparison to the advanced real-time capabilities that Polhemus offers with its magnetic solutions."

The Polhemus Solution

Skill's client base is primarily research oriented; therefore, it was critical that they had the advantage of true real-time motion analysis. The Polhemus FASTRAK® offers users the ability to accurately compute the position and orientation of a tiny receiver as it moves through space. This device virtually eliminates the problem of latency as it provides dynamic, real-time measurement of position and orientation.

"Polhemus offers us 6 Degree-Of-Freedom, real-time motion capture," said Cheetham. "That is critical to the biomechanics community and the clinical world. Our customers don't have the time to deal with the extensive and tedious post-processing required of other solutions on the market. Polhemus' dynamic capabilities are integral to our customer's success."

With 6D-RESEARCH, Skill Technologies provides a means to track, quantify, display and document true 3D motion of the human body, in real-time. It provides an accurate three-dimensional, 6DOF system that captures and dynamically displays motion using fully rendered 3D graphical models and parameter graphs. 6D-RESEARCH allows the user to define a body segment for each sensor. The segments are then scaled and positioned, creating a precise fully rendered 3D graphic model that moves simultaneously with the subject.

This is critical for Skill's growing customer base which includes leading providers of biomechanics, kinesiology, sports medicine, physical therapy, sports instructors and others. For example, the University of Connecticut's Department of Psychology is using 6D-RESEARCH to study postural control and limb proprioception. In this study, the university is researching how the human body "knows" Polhemus virtual golf training and swing analysis systemwhere the different parts of the body are located.

Another example is the University of Alberta, Canada's, division of neuroscience using it to measure 3D tremor in patient's hands, wrists and arms to study diseases such as Parkinson's Disease. By being able to measure the actual intensity of the tremor, they can determine the precise amount of drugs needed to treat the disease, resulting in tremendous cost-savings for very expensive medication.

A very innovative application of the Polhemus FASTRAK is in Skill's latest product called 3D-GOLF. 3D-GOLF is a virtual golf training and swing analysis system that can be used by golf teaching professionals. Its most unique feature is its biofeedback capability, which is provided by FASTRAK's real-time response. The biofeedback mode utilizes audio tones to help the student hear and "feel" a good swing. When a student deviates from the specified movement envelope the computer beeps. This facilitates better teaching and faster learning.

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