Tools designed to capture movement in 3D can also enable doctors to provide tailored treatment and rehabilitation programmes for patients who have suffered a stroke.
Although still at the development stage, 3D technology has made a resounding impact on the general public through its widespread use in the video games industry. Film and video games creators use motion capture technology to convert human movements into computer animations, opening up a whole new dimension for animated productions. As often happens however, this technology, which was specifically developed for mass entertainment production, can find other uses outside the confines of this sector. Now a group of researchers at the University of Gothenburg in Sweden has come up with a valuable application of this technology – along the lines of programmes developed on the basis of Microsoft’s Kinect – that is likely to be of enormous benefit to the medical sector and help to improve the doctor-patient relationship. The team has discovered that information obtained when stroke patients are given movement capture sensors to wear enables medical practitioners to design tailored treatment which is far more effective in the rehabilitation of certain motor functions.
Precise motion data
During their research, the Swedish scientists used motion-capture technology to film the everyday movements of people who had suffered a loss of motor skills following a haemorrhage or blockage in the brain’s blood vessels, generally known as a ‘stroke’. They then made a virtual reconstruction of the various movements the patients made. This simulation allowed the researchers to analyse more closely the various difficulties experienced by the patients, especially the most critical areas of mobility impairment. “With 3D technology, we can measure a patient's movements in terms of numbers, which means that small changes in the motion pattern can be detected and can be fed back to the patient in a clear manner,” explains Margit Alt Murphy, a researcher on the Gothenburg team. In the study, the test subjects were equipped with small, round reflex balls on their arm, trunk and head, and were then asked to drink water out of a glass. The motion was documented by high-speed cameras using infrared light which was reflected by the balls and then fed into a computer where they create a 3D animated image in the form of a stick figure. “With 3D animation, we can measure the joint angle, speed and smoothness of the arm motion, as well as which compensating motion patterns the stroke patient is using,” points out the Swedish researcher, adding: “This gives us a measurement for the motion that we can compare with an optimal arm motion in a healthy person.”
Still expensive technology
3D animation thus provides the doctors with far more accurate information, which can also be made available to the patient. Comparing his/her movements on screen with those of healthy people can serve to highlight gaps and problems which may not be debilitating or obvious enough for the patient to be aware of them. The technology will enable physicians to distinguish real difficulties, without the analysis being obscured by the compensatory motion patterns a stroke victim unwittingly makes. However, the technology is still very expensive and moreover requires prolonged use before medical staff are able to grasp and analyse the full range of movements that the patient may perform, and in which situations. Nevertheless, “even if this technology is not available, we can still obtain very valuable information about the stroke patient's mobility by timing a highly standardised activity, and every therapist keeps a stopwatch in their pocket,” reveals Margit Alt Murphy.