The MiAssiSt Arm Support

Project by: Jessica Gantenbein


This project was a master Thesis conducted by Jessica at the Rehabilitation Engineering Lab at ETH in Zürich. Jessica started her journey into wearable assistive robotics with the EduExo exoskeleton. She was able to use many of the things she learned building the EduExo to develop  a new assistive device in six months, while working very closely together with the user.


Before the start of this master thesis project, Jessica met Mike. Mike was born with the neuromuscular disorder spinal muscular atrophy (SMA), which leads to a progressive decrease of his muscle strength over the years of his life, which leads to him facing different challenges in daily life, one of them being too weak to lift his arm to eat or drink independently. This soon yielded in his need for an assistive device which helps him to overcome this challenge.


Throughout the next year, Mike and Jessica developed the MiAssiSt together – a wheelchair-mountable assistive device that helps Mike to eat and drink independently again. By today, Mike is happily using the MiAssiSt at home on a daily basis for a few months now. Due to this success, the developers decided to make their idea freely accessible and adaptable for anyone who might have similar needs as Mike and to anyone who is interested to learn more about the development of assistive devices.

Concept for the wheelchai mounted assistive device.
Concept for the wheelchai mounted assistive device.


The MiAssiSt is a DIY, wheelchair-mountable assistive device to support users with reduced upper limb muscle strength in various ADLs such as eating, drinking, or using computers. It consists of a passive counterweight and an active add-on. The adjustable counterweight passively compensates for the weight of the lower arm and enables the user to use his remaining muscle strength as often as possible. If needed, the active add-on provides additional support for lifting heavier objects such as a full glass of water. The add-on is controlled by the index finger of the unsupported arm.

design of the wheelchair mounted assistive device.
design of the wheelchair mounted assistive device.


The project resulted in a fully functional device that was mounted to Mike's wheelchair. A picture of the device is shown below.

To enable other people to learn from her their results, Jessica, Mike and the Rehabilitation Engineering Lab at ETH Zürich published made the design available open source. You can find a download link below.


Jessica herself moved on and became a PhD student working on assistive technologies.


Link to the project:


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Compressed Archive in ZIP Format 7.2 MB

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