Samenvatting

Standing up is harder to perform when getting older. The company SillaPlus want to create a physical device that can be attached to already existing chairs and will help elderly people get up from a chair. The company reached out to students who want to help with the development of a get up aid. The first steps to reach this goal were undertaken by student Jelles Overmeen. He investigated the ideal horizontal position of placement of the arms while standing up. Left to investigate were the measurements that the device need to meet and the appropriate height of the armrest.
The aim for this project is to create a physical device that can be attached to different existing chairs that are frequently used in nursing homes that helps elderly people stand up, while maintaining a secure feeling.
The project is divided in phases: an analysis-,design-, construction- and evaluation phase. The first part of the analysis phase consist out of literature research. Found was that muscle quality in the arms is significantly higher than the muscle quality in the legs with increasing age. An users survey is performed by analyzing mentioned pros and cons in product reviews from users from comparable products. For deciding which measurements the device has to meet, dimensions from chairs in nursing homes are measured. Finding the appropriate vertical position for the armrest is investigated by performing EMG measurements on the m. vastus lateralis (VL) and m. triceps brachii lateralis (TBL), while a subject stood up from a chair using different heights of armrests. The armrest height where the least muscle activity is shown in the VL was the height for the subject. The angle of the elbow was measured using videos. By analyzing the average angle of the elbow on this armrest height, and assuming this is the ideal force-length relationship, the armrest height for 90% of the target group can be calculated. The list of requirement and wishes is fulfilled with the addition of the analysis results. For the design phase different methods are applied: brainstorming, clustering with the help of a morphologic map, concept development and rating the concepts with the cardinal method. The construction phase is performed by creating technical drawings and a working model. During the evaluation the final design is discussed with the help of the list of requirements and wishes.
The users survey lead to minimum result. Most pros and cons were already mentioned in the list of requirements and wished. With the dimension measurements from the chairs, a small database is created. At an armrest height of 25 cm the VL showed the least activity in the subject. With this result is calculates that the device needs to be able to vary in height between 20,1 and 25,2 cm. By following the design methods a final design is developed. The device has four legs that are positioned on the floor. It can be attached to the chair with an flexible strap.
The design meets most of the requirements and wishes. However, not all requirements are evaluated yet. During the EMG measurements one subject is used. The subject is younger than 65 year. A large list of requirements followed out of the analysis. It was hard to make sure that the device would meet the requirements, and designing a compact device with a small adjustability’s.