maandag 28 februari 2011

Scale

We found a cheap scale in a 'Blokker' store. There are 4 seperate pressure sensors in it. These can be used to put under the legs of a chair.

First Ideas

These are the first ideas for the weighing mechanism:


Idea 1: 
This idea consists of presure points that can be placed under the legs of a chair. 


Idea 2:
This system can only be used on a chair with one leg. The advantage is that there's only one pressure sensor needed and there are less cables (less messy).


Idea 3:
This idea is basically some sort of add-on to use with a regular scale and a chair. The disadvantage of this system is that the display is not well readable. 


Idea 4:
This idea uses plastic tubes filled with water. The weight of the person causes pressure in the tubes. One can read the weight on the height of the water surface.


Idea 5:
This idea uses the system of a traditional scale with springs. (mechanical scale)

vrijdag 25 februari 2011

Meeting with Henk 1: What are the problems

During the first meeting with Henk, we discussed the most important problems that he encounters if he has to weigh himself.


Problems:


- With a normal scale, Henk has to sit on the scale and try to balance. This is very difficult because he doesn't have stability in the lower part of his spine. He also has to grab his legs and while doing this he has to manage to read the little display. All these thing together make it a nearly impossible task to weigh himself.


- The scales that are designed to use with a wheelchair are very large, heavy and bulky. They are also expensive and are not designed for usage at home. 






- The scales that are designed for wheelchairs use a big plate onto which the wheelchair user has to drive. The wheelchair has a weight too, so in order to determine the weight of the wheelchair, the wheelchair user has to get out of the wheelchair, weigh the the wheelchair and get back into the wheelchair to determine his own weight. 


Possible solution:


- For Henk it's easy to switch between a wheelchair and a normal chair. So a possible solution is to design a scale with separate pressure sensors that can be placed under the legs of a chair. It's also important that the display is placed on a location where it's readable. Another important aspect is that the scale has to be as compact as possible so the scale can be put away. The scale also needs a 'zero button' to cancel the weight of the chair.



Rapport ergotherapiestudenten