lever wheelchair - Eco - Mobilność

lever wheelchair

project tasks » wheelchairs » lever wheelchair

Young disabled people with lower limb impairments desire to increase their mobility especially at longer distances. At the same time physiotherapists responsible for their development pointed out many times great importance of continuous rehabilitation for their both physical and mental health. The response of the Eco-Mobility project to the needs of these people is a lever-driven wheelchair concept. Lever wheelchairs are already in use, but they are not yet popular – who of us have seen a lever wheelchair in their life? From current studies one can conclude that in comparison to the classic push-rim wheelchairs they have many advantages. First of all safety of lever wheelchair user is greater because of the constant contact of hand-lever which takes place far away from the rotating back wheel. The constant contact feature is also an advantage for quadriplegic people who find it difficult to perform a hand grip. Rehabilitation process of lever wheelchair user is also faster and more thoroughgoing because of the fact, that working with levers involves more muscle groups of their user.  Some lever wheelchairs allow changing gears (similar solution to bicycles) which makes riding at a distance in changing terrain easier.

An important drawback of lever wheelchairs is that they don’t allow carrying out manoeuvers at such ease as classic push-rim wheelchairs are. Described above features help to classify lever-driven wheelchairs as designed for sports and recreation outdoors.

 

The contribution of the “Eco-Mobility” project into development of the lever wheelchair concept is optimizing the user-wheelchair cooperation regarding lever placement in reference to the user. In order to assess this ergonomic work conditions we have built a mechatronic simulator of lever wheelchairs. The simulator allows changing values of different lever parameters, most of all levers’ length and their axis of rotation position in relation to wheelchair user. Thanks to the loading system built out of two separate flywheels with electromagnets it is possible to simulate natural resistance to motion in various situations – while climbing a hill or riding against wind. Also, the simulator creates the impression of real motion thanks to the real-time-displayed visual interface visible in front of the user.

 

Building of the simulator allowed carrying out experiments with use of various techniques measuring human work performance:

EMG – for the assessment of local muscle fatigue;

oxygen consumption – for the calculation of human exerted work;

heart beat measurement – for general information about the users’ work-related effort

The experiments led to optimizing the length of levers and position of their axis of rotation.

 

 The “Eco-Mobility” project also allowed designing first pre-prototype of a lever wheelchair built in the Warsaw University of Technology. The structure is heave, however it allowed us to test various ideas for wheelchair construction including innovative braking system.

 

 

List of published works related to the task:

1. Patent application (regarding lever wheelchair simulator) P-400484 – pt.: "Stanowisko do badania wózków dźwigniowych" – twórcy Włodzimierz Choromański, Andrzej Potyński, Grzegorz Dobrzyński, Krzysztof Fiok – zgłoszenie z dnia 23.08.2012 r.

2. Doctoral dissertation "Parametric optimization of an innovative manual wheelchair", K. Fiok, 12.2013 

3. Choromański W., Fiok K., Dobrzyński G.: Optimizing the lever propelling system for manual wheelchairs, Bulletin of the Polish Academy of Scienses – Technical Sciences, December 2012, pp. 793-800. DOI: 10.2478/v10175-012-0092-8 (czasopismo indeksowane w JCR

4. W. Choromański, K. Fiok, G. Dobrzyński i inni: Lever driven wheelchair for active disabled people, materiały konferencyjne z seminarium Polsko-Chińskiego “Eco-Mobility – innovative technologies”, ITS 16-17.06.2011 r., ISBN 978-83-60965-93-1, Warszawa 2012r. str. 139-148

5. W. Choromański, G. Dobrzyński, K. Fiok i inni: Electric wheelchair with the ability of climbing stairs, materiały konferencyjne z seminarium Polsko-Chińskiego “Eco-Mobility – innovative technologies”, ITS 16-17.06.2011 r., ISBN 978-83-60965-93-1, Warszawa 2012r., str. 124-138 

6. Choromański W., Dobrzyński G., Fiok K.: Optimization of Lever-Driven Wheelchairs; IFMBE Proceedings - 6th World Congress of Biomechanics (WCB 2010). August 1-6, 2010 Singapore, vol.31, Wyd. Springer, 2010, str.671-674

 

Picture gallery:

Pre-prototype of a lever-wheelchair

Pre-prototype of a lever-wheelchair

Pre-prototype of a lever-wheelchair

Pre-prototype of a lever-wheelchair

Mechatronic simulator of lever wheelchairs

Mechatronic simulator of lever wheelchairs

Mechatronic simulator of lever wheelchairs

Mechatronic simulator of lever wheelchairs