'Thought control' enables spinal injury patient to ride a bike

It’s an old adage that as human beings, we can do anything we want if we believe in ourselves. Now researchers at the Gold Coast Health and Knowledge Precinct (GCHKP) are bringing this cliché to life, using a 3D computer-simulated biomechanical model and an electroencephalogram (EEG) to stimulate movement — and eventually recovery — in quadriplegics.

Dr Dinesh Palipana, a junior doctor at Gold Coast University Hospital and graduate of Griffith University, has a vested interest in the research. A quadriplegic himself, he wants to see a cure for spinal cord injury in his lifetime. He is thus quite happy to be the “guinea pig” of the GCHKP project, teaming up with Griffith’s Professor David Lloyd and Dr Claudio Pizzolato in what is said to be the first step towards a world-first integrated neuro-musculoskeletal rehabilitation program.

As noted by Professor Lloyd, the development of these neuro-mechanical models has been a project 25 years in the making. It is only recently, however, that the research team has succeeding in personalising these models and making them work in real time. “And so we’re going to take those models and create a twin of a patient who is a quadriplegic like Dinesh,” he said.

“We will use that model to help us understand how to activate these muscles through stimulation to do rehabilitation on a bicycle or a reclined bicycle, which you can use for people who are quadriplegic. We’re also connecting it to EEG equipment.

“The idea is that a spinal injury or neurological patient can think about riding the bike. This generates neural patterns, and the biomechanical model sits in the middle to generate control of the patient’s personalised muscle activation patterns. These are then personalised to the patient, so that they can then electrically stimulate the muscles to make the patient and bike move.

“It’s all in real time, with the model adjusting the amount of stimulation required as the patient starts to recover.”

“We’ve had equipment for many years where people passively exercise using stationary bikes, and stationary methods where people get on and the equipment moves their legs for them,” Dr Palipana explained. “The problem is you really need some stimulation from the brain.

“As the years go by we’re starting to realise that the whole nervous system is very plastic and it has to be trained, so actually thinking about moving the bike or doing an activity stimulates the spinal cord from the top down and that creates change.”

This top-down, bottom-up approach effectively provides a substitute connection between the limbs and the brain where it was previously broken when the spinal cord was injured. And while the study is still in its early stages, Professor Lloyd said the researchers “have shown our real-time personalised model works”, with Dr Palipana successfully moving himself along on a specially adapted recline bike simply by thinking about pushing its pedals.

The neuro-rehabilitation research is also set to dovetail with a related study by Griffith’s Associate Professor James St John, who has had seen promising results for his biological treatment using olfactory cells to create nerve bridges to regenerate damaged spinal cords. Professor Lloyd explained, “You use the modelling to recreate the connection, and over time, with the science of Associate Professor James St John, you establish new neural pathways.

“So over time patients will be less dependent on the model to control the bike movement and it will move back to their own control, with their regenerating spinal cord and their reprogrammed neural pathways.”

Associate Professor St John aims to move into human clinical trials in the GCHKP within the next 2–3 years. Professor Lloyd and his team meanwhile hope to refine their rehab testing and develop the technology with leading global companies in exoskeleton design.

Image caption: Dr Dinesh Palipana with Professor David Lloyd (left) and Dr Claudio Pizzolato (right).