Development and construction of a measuring system for the evaluation of a dynamic wheelchair
by Mahmud Nuh Hazini
Task definition:
In order to assess the loads that occur and the effectiveness, a measurement system must be developed that enables a meaningful statement and comparison between a static and dynamic seat shell by measuring relevant parameters.
Method:
A belt force sensor was produced to determine the tensile forces on the seat shell’s fixing belts that arise during a dyskinetic extension movement. The belt force sensor was attached to the lap and foot restraint belts. The resulting force is almost completely converted within the belt into the bending of the aluminum carriers of the belt force sensor. This bending of the aluminum beams is detected by the strain of the attached strain gages and converted into a change in resistance that is directly proportional to the acting force. To measure the change in resistance of the strain gages, the strain gages are bonded and wired into a full Wheatstone bridge on an aluminum carrier.
Results:
The tests with test subjects showed a significant reduction in tensile forces in the dynamic seat shell compared to the static seat shell. The reduction is over 50% in some test subjects. After carrying out a significance test, the data collected could be described as significant.
Discussion:
The methodology used here provided reproducible and meaningful results on the applicability of the dynamic seat shell. However, the positive reduction of forces in the dynamic seat shell must be confirmed by further studies.
Summary:
The methodology used here provided reproducible and meaningful results on the applicability of the dynamic seat shell. However, the positive reduction of forces in the dynamic seat shell must be confirmed by further studies.