Brain Computer Interface: Neuroprosthetic Control of a Motorized Exoskeleton

Traumatic Tetraplegia with Cervical Cord Injury

without associated head injury

The BCI project falls within the very broad field of brain machine interfaces. Its multiple applications include the compensation of motor deficits. The subject of the present protocol is the first test of the system in man on the compensation of motor deficits by an epidural brain implant enabling an electrocorticogram (EcoG) to be recorded.

Injuries to the cervical spine and to its contents, the spinal cord, cause serious neurological deficits, with loss of motor function and sensitivity of the four limbs, resulting in quadriplegia. The level of the lesion separating the area without deficits, above the lesion, from the sub-lesional area depends on the extent of the spine injury (dislocation, fracture or trauma without final displacement), may cause spinal cord injuries of varying severity, which can range from the benign to a complete section that results in complete and irreversible sensorimotor deficits. Lesions from C1 to C4 are often immediately fatal or cause diaphragmatic paralysis (innervated by the phrenic nerve whose roots originate at C4). C4-C5 paraplegia and below are therefore compatible with life as they spare respiratory autonomy, although they lead to severe permanent disabilities, creating a state of severe dependence in subjects who are often young. The problems created by these patients are those of an extremely heavy individual, family, and societal burden in addition to the individual drama. While paraplegics, by maintaining their motor skills and sensitivity of both upper limbs and back muscles can often reintegrate and find remarkable mobility with wheelchairs, this is not the case of quadriplegics who must be provided with substitutes in order to achieve an acceptable quality of life. This project offers a highly innovative approach by means of a motorized exoskeleton that enables standing, walking and the use of the upper extremities. The validation of the first step of this concept will pave the way for developing increasingly sophisticated exoskeletal neuroprostheses, aimed at giving these patients compatible and ever greater autonomy.

France