Technology Spain , Salamanca, Friday, May 15 of 2015, 12:48

A system increases the possibilities of handling a wheelchair

A project of the University of Salamanca allows the control of wheelchairs by voice, mobile devices, or by using a helmet that interprets thoughts to increase the independence of people with various disabilities

José Pichel Andrés/DICYT The BISITE research group of the University of Salamanca has developed a system that can be adapted to all motorised wheelchairs on the market and which allows people with very different disabilities to control for themselves movements that they would not be capable of making in conventional wheelchairs. In this way they increase their independence and considerably lessen the work load of their carers or relatives and also allow the monitoring of their movements from a distance.


“Traditional motorised wheelchairs have a lever that requires a physical effort that not all users are capable of, for example those who cannot move their upper limbs or can only do so with difficulty”, DiCYT was told by Gabriel Villarrubia, one of the experts in charge of the project. However, with the devices that this group of researchers has designed that can be coupled to any wheelchair model the ways of controlling movements are multiplied. The wheelchair user can direct it with his/her voice or put on a helmet that interprets his/her gestures and movements, while a relative or carer can also control the wheelchair from external interfaces, such as a mobile phone, a tablet, or a computer.


The researchers Juan Francisco de Paz, Daniel Hernández, and Alberto López are also taking part in the project, which is so promising that it was awarded a prize in the I Cross-border Competition of Market Orientated Prototypes, Prototransfer, an event which is developed as part of the international project INESPO II. One of its advantages is its low cost as the basic electronic components that the team has developed and which are connected by Bluetooth cost about 150 euros. “It is a cheap part that is connected to the batteries of conventional wheelchairs and which is very simple to install”, they comment.


The voice control has been designed for those who cannot move. “It has controls for movements such as moving forward, moving backwards, or turning, but it also allows conversations with the wheelchair so that it is possible to consult the news or the weather, turn on the lights that we have added to the system, or send an emergency signal to the police”, Gabriel Villarrubia points out.


The wheelchair can also be controlled from a mobile phone not only by its user but also by a companion. It suffices to tilt the mobile to one side to indicate the desired movement. Another option is the tablet, with which one slides a hand across the screen in the direction of the movement. Moreover, all these possibilities can be personalised; in other words "the movements or speeds can be adapted to each person's needs”.




Nevertheless, the most innovative control type is that provided by the helmet, which allows the detection of any physical stimulus such as moving one's tongue to one side, clenching one's teeth, blinking, opening one's mouth, or making a face. The researchers can give a specific interpretation to each of these movements to make the wheelchair move or activate one of its functions. In common with the remainder of the components of the system, it also operates by Bluetooth.


This is an innovative helmet that is generally only sold to universities or research centres for R+D projects; it is being used by many scientists for psychology or communication research into matters such as driving patterns or how many times a person laughs when watching a film.


However, it not only detects physical movements. By means of its 16 electrodes it registers the brain's electric activity. “When making a mathematical calculation, thinking of a situation that makes us happy, or of another that makes us afraid, the sensors that are activated are different and we are confirming this empirically”, those in charge of the project affirm. From this starting point a person can be trained so that whenever he/she wants to move to one side he/she must concentrate on a certain type of thought. “After half an hour's training up to four different movements can be achieved”, they affirm.




Although the user movements are not perfect, the system incorporates to the wheelchair obstacle sensors so as to avoid collisions and other mishaps. For example, if one approaches stairs the sensor can detect that there is too great a distance between the wheelchair and the floor and prevents it from continuing.


On the other hand, the system also incorporates cameras that at a given moment may allow the remote control of the wheelchair by using the Internet. “If a person goes out and has a problem, a relative can get connected from a distance and put on glasses that allow him/her to see the situation as if he/she were sitting in the chair and ordering the appropriate movements”, comments Gabriel Villarrubia. This function is also useful as preliminary training for any user of the wheelchair.


Moreover, the system can be connected to OpenStreetMap, a project for publishing free maps that includes among its data pedestrian crossings adapted for wheelchairs so that routes can be drawn up to include the most suitable places through which to pass. Likewise the system estimates the range of the movements depending on the battery charge; in other words "it tells the user how far he/she can go and draws this on a map”.