2014, Volume 10, Issue 1
The influence of the scenery and the amplitude of visual disturbances in the virtual reality on the maintaining the balance
Robert Michnik1, Jacek Jurkojć1, Piotr Wodarski1, Marek Gzik1, Andrzej Bieniek2
1Katedra Biomechatroniki, Wydział Inżynierii Biomedycznej, Politechnika Śląska, Zabrze, Poland
2SKN Biomechatroniki BIOKREATYWNI, Wydział Inżynierii Biomedycznej, Politechnika Śląska, Zabrze, Poland
Author for correspondence: Robert Michnik; Katedra Biomechatroniki, Wydział Inżynierii Biomedycznej, Politechnika Śląska, Zabrze, Poland; email: robert.michnik[at]polsl.pl
Background and Study Aim: The process of the maintaining the balance is a very important human skill. All the changes, which impair the steering system or executive system are reflected in the changes of balance. The results of stabilographic research are widely used in supporting the diagnostic process, sport training as well as they are a very useful tool which makes therapeutic effects objective and are used to define the degree of disability. The connection of Virtual Reality Technologies with stabilography gives the unprecedented results. It allows you to carry out the tests which very often require highly professional equipment . Therefore it turns out to be very important to use the parameters of the world artificially created with the use of the Virtual Reality Technology on the ability to keep balance. The purpose of the research was the relationship between the parameters that change in the virtual reality (amplitude of scenery movement and type of scenery) and the measured stabilographic parameters (length of the path, the area of the ellipse and the value of the deviation of the location of the centre of pressure).
Material and Methods: The research has been made to define the influence of the type of the virtual reality scenery and it’s movement amplitude on the stabilographic values. Five tests were carried out with the participation of a group of 15 students of the Silesian University of technology at the age of 20-26 (8 women and 7 men).
Results: The measurements of the length of the path, the area of the ellipse and the value of the deviation of the location of the centre of pressure – COP - in the sagittal plane were carried out. The average movement velocity of the centre of pressure was also measured. Average values for the whole research group were defined and the time - frequency analysis of the COP deviation was done.
Conclusions: The analysis of the results showed that the type of the used scenery has a significant impact on the length of the support path, area of the ellipse and velocity of COP movement. In the closed scenery, where the patients are located inside a room or close to the objects, it was observed that there has been a greater impact of the amplitude changes on the above mentioned parameters than in an opened scenery where the examined person is placed in a wide open space. There was also observed an effect of counteraction of the system stabilizing the posture to the visual stimuli. The conducted measurements are the first phase of a project, which aim at developing the system enabling research into human motion system with the use of Virtual Reality Technology.
Key words: body balance, impact, virtual reality technology