Past and Future of the Intelligent Wheelchair of Zaragoza (Spain)

In our current society there are an increasing number of people with limited motor capabilities due to degenerative diseases or other pathologies, accidents or age for example. In some cases, these motor disabilities have also associated some cognitive impairment. Robotic wheelchairs are a special type of help care vehicles whose objective is to improve the quality of life of these people increasing their mobility and autonomy.  

In the last 6 years, in the University of Zaragoza of Spain, the Group of Robotics has developed an intelligent robotic wheelchair. The device is a commercial wheelchair equipped with sensors and computers and the most important, the artificial intelligence – based navigation technology, which is able to autonomously drive the vehicle among locations while negotiating obstacles and collisions. Many other functionalities have been deployed like PDA control or people tracking and following with applications in supervision of a fleet of wheelchairs in public scenarios like residences or hospitals. Recently, we have addressed the last step related with the real users of the wheelchairs. The focus was on children with cognitive diseases.

When the final users are cognitive disabled, the interface has a strong impact that constrains all the application. In general, the work goes beyond the robotics and human machine interfaces and it is necessary to develop additional tools to help and teach them to understand the interface and the relation with the wheelchair robot and its autonomous motion. We constructed three types of generic and adaptable interfaces to cover the different mobility cases: (i) possibility of arm control (tactile screen), (ii) control of single parts of the body, i.e. one finger, (single push button), and (iii) speech capabilities[1] (voice interface with no body control required). Using the interface, the children commanded the wheelchair while the autonomous navigation system executed the motion liberating the user from the low level control of the vehicle and assuring collision free motion.

In 2006 July, five children used the wheelchair during one week in their school (Colegio Público de Educación Especial Alborada) and in the corridors of our University. All of them successfully used the robotic wheelchair in their usual school day. They liked a lot the experience and the wheelchair performance showed to be really useful, since some of these children cannot manage by their own their non-electric wheelchairs. I strongly believe that to be able to use these technologies with these children really converts them in a reality.  

In order to continue this research line, a multidisciplinary team led by myself has recently obtained financial support with a Spanish project called “Biological Human – Robot Interaction for Mobility” starting in 2007 January. This project focuses on the biological interaction between humans and robots. The objective is to supervise, evaluate and control machines using biological parameters of humans such as cerebral, cardiac, or respiratory activity. In the short term there are two applications.

·         The first one is related with elder persons with some pathology. The objective is to build a system that supervises the biological parameters of the humans while using the wheelchair. Then, the system will be able to detect anomalies in the cerebral, cardiac or respiratory activity that could correspond to non desirable situations and to send an alarm flag to an external computer. This external computer could warn the responsible or carer of the person.

·         The second one is more related with persons with severe diseases like brain stem or nonhemorrhagic stroke in the ventral pons that can cause the locked-in syndrome: tetraplegia and paralysis of cranial nerves. These patients are said to be “locked in” since they are conscious and alert but they cannot use their mussels and therefore cannot communicate. The objective is to construct a brain-computer interface to allow them to command our intelligent wheelchair. This would be a large step in improving their autonomy and quality of life.

I hope that we will have some of these demonstrators working in the next 2 years.

The long term vision of the project is to use the entire biological human signal in order to influence the motions of the vehicles. Human transportation by autonomous vehicles is coming soon. Cars, buses, personal – displacement systems, wheelchairs, etc would be equipped with autonomous motion systems. However, it is clear that for many applications, this motion has to be different and adapted to each person: children, elders, and persons with some pathology, etc. In the near future, the vehicles or robots will have to adapt their motion to people and one way to do it is to use their biological response. This is a very difficult and challenging direction of research!

PhD Javier Minguez

“Ramón y Cajal” researcher

Robotics Group

University of Zaragoza