Published in the Journal of NeuroInterventional Surgery, the results found the Stentrode was able to wirelessly restore the transmission of brain impulses out of the body, enabling the patients to complete daily tasks such as online banking, shopping and texting, which previously had not been available to them.
The Royal Melbourne Hospital’s Professor Peter Mitchell, Neurointervention Service Director and principal investigator on the trial, said the findings were promising and demonstrate the device can be safely implanted and used within the patients.
“This is the first time an operation of this kind has been done, so we couldn’t guarantee there wouldn’t be problems, but in both cases the surgery has gone better than we had hoped,” Prof Mitchell said in a statement.
Prof Mitchell implanted the device on the study participants through their blood vessels, next to the brain’s motor cortex, in a procedure involving a small ‘keyhole’ incision in the neck.
“The procedure isn’t easy, in each surgery there were differences depending on the patient’s anatomy, however in both cases the patients were able to leave the hospital only a few days later, which also demonstrates the quick recovery from the surgery,” Prof Mitchell said.
Associate Professor Thomas Oxley, a neurointerventionalist and CEO of industrial research partner Synchron, said this was a breakthrough for brain-computer interfaces.
“We are excited to report that we have delivered a fully implantable, take home, wireless technology that does not require open brain surgery, which functions to restore freedoms for people with severe disability,” he said.
The two patients used the Stentrode to control the computer-based operating system, in combination with an eye-tracker for cursor navigation.
They also undertook machine learning-assisted training to control mouse click actions, including zoom and left click. The first two patients are said to have achieved an average click accuracy of 92 per cent and 93 per cent, respectively, and typing speeds of 14 and 20 characters per minute with predictive text disabled.
University of Melbourne Associate Professor Nicholas Opie, co-head of the Vascular Bionics Laboratory at the University and founding chief technology officer of Synchron said the developments were exciting and the patients involved had a level of freedom restored in their lives.
“Over the last eight years we have drawn on some of the world’s leading medical and engineering minds to create an implant that enables people with paralysis to control external equipment with the power of thought. We are pleased to report that we have achieved this."
The researchers caution the technology is some years away from being publicly available, adding that the global, multidisciplinary team is working to make this a reality.