The wheelchair is still considered experimental and expensive, but a project recently approved by FAPESP’s Innovative Research in Small Business (PIPE) programme aims to adapt the technology to make it more affordable and marketable in Brazil within two years.
“We want to make sure the end-product costs no more than twice as much as an ordinary motorised wheelchair, the kind controlled by a joystick, which currently costs about US$2,000 (RM8,000) said Eleri Cardozo, a professor at the University of Campinas’s School of Electrical & Computer Engineering in São Paulo (FEEC-UNICAMP).
Cardozo presented the results of his group’s research during the third BRAINN Congress, which took place in Campinas on April 11-13, 2016.
According to Cardozo, the technology can be used by people with tetraplegia, stroke victims and patients with amyotrophic lateral sclerosis or other conditions that make fine hand movements impossible.
The research began in 2011 and was initially supported by FINEP, the Brazilian Innovation Agency.
Currently, it is ongoing under the aegis of the Brazilian Research Institute for Neuroscience and Neurotechnology (BRAINN), one of the Research, Innovation and Dissemination Centers (RIDCs) funded by FAPESP.
“Our group was studying brain-computer interfaces, or BCIs, and we thought it would be interesting to evaluate the technology in a real-life situation,” Cardozo recalled.
BCIs involve signal acquisition and processing methods that permit communication between the brain and an external device.
The group then purchased a conventional motorised wheelchair, removed the joystick and fitted the wheelchair with several devices typically found in robots, such as sensors capable of measuring the distance to a wall or detecting a sloping floor.
The prototype was also equipped with a notebook computer that sent commands directly to the wheelchair and a 3D camera with Intel’s RealSense technology, which enables the user to interact with a computer by means of facial expressions or body movements.
“The camera identifies more than 70 points on the face – around the mouth, nose and eyes – and simple commands can be extracted from movements at these points, such as forward, back, left or right, and, most importantly, stop,” Cardozo said.
The user can also interact with the computer by voice command, but this technology is considered less reliable than facial expressions because of differences in vocal pitch or timbre, as well as possible interference by background noise.
Thinking of patients with especially severe tetraplegia, who cannot use facial expressions, the group is also working on a BCI device capable of extracting signals directly from the brain via external electrodes and converting them into commands.
They have not yet found a way to integrate the device into the robotized wheelchair.
– Agência FAPESP