China develops brain implant enabling patient to control computer cursor movement

BEIJING, Feb. 28 (Xinhua) -- Reflected in the intense gaze of a 35-year-old man with tetraplegia, a red ball responds to the man's thoughts and moves slowly across a screen toward a blue ball target, eventually approaching and overlapping it.

This is not a scene from a science fiction movie, but the result of a recent breakthrough China has made in the brain-machine interface field.

A team led by professor Hong Bo at Tsinghua University, in collaboration with a team led by professor Jia Wang at the Beijing Tiantan Hospital under Capital Medical University, was recently successful in helping the patient use his mind to control cursor movement on a screen.

The patient has had an injury in the C3-C4 cervical spinal segments from a car accident five years ago, resulting in the complete loss of self-care abilities. With the informed consent of the patient and his family, Jia's team last December performed a minimally invasive, wireless brain-machine interface implantation surgery using an implantable Neural Electronic Opportunity (NEO) device.

"To protect the patient's nerve cells from damage, we placed the electrodes outside the dura mater responsible for motor and sensory functions around the central sulcus of the brain during surgery," Jia said.

Through multiple comparisons and verifications made using advanced techniques such as intraoperative navigation, neurophysiological monitoring and mixed reality imaging, the team ensured the precise positioning of the electrodes, as well as clear and stable electrical signals in the brain. The patient was discharged 10 days after the surgery, according to Jia.

The NEO device utilizes near-field wireless power supply and signal transmission, meaning the implant is battery-free. The research team guided the patient through wireless brain-machine interface-assisted rehabilitation remotely.

After two months of careful training, the patient's motor skills recovered the extent that he was able to complete tasks such as fetching a bottle of water using an air-filled glove driven by brain waves, and he also accomplished thought-controlled cursor movement on a computer screen in a normal household environment.

"The 'chasing' of the red ball by the blue ball, seemingly a simple movement, signifies the interaction between the patient and electronic devices through the brain-machine interface, paving the way for more profound functionalities in the future," Jia said.

This achievement has been attributed to the precise implantation of the electrodes, and to the efficient transmission and accurate decoding of brain signals -- the result of the strong cooperation between the two teams.

Hong said that the team is continually optimizing brain-machine interface decoding algorithms. It is planning to help patients achieve control in actions such as flipping through an e-book or clicking a cursor using their minds, aiming to enhance interactive patient-device capabilities.

The successful implantation of the minimally invasive, wireless brain-machine interface and the first successful brain-controlled cursor movement are expected to provide a new direction for the rehabilitation of patients with tetraplegia, amyotrophic lateral sclerosis and other neurological disorders, offering new possibilities to many people hoping to restore their physiological functions.

It is understood that the minimally invasive, wireless brain-machine interface project was initiated by Tsinghua University in 2016, followed by the manufacturing of a prototype device in 2019 and the commencement of animal experiments in 2020. At the end of 2021, Beijing Tiantan Hospital joined the project, participating in the design of clinical scenarios, planning clinical technical routes and designing surgical implantation methods.