Two patients with complete tetraplegia, a condition of paralysis from the shoulders down, were once again able to grasp objects and perform everyday activities, such as holding a can or eating with fork, through the use of a neurostimulation device designed by Neurinnov under the AGILIS study, led by Inria.
Within a few days of the surgery, the patients were quickly able to grasp objects in two distinct ways. Using three movements: open and close the hand, either in « palmar grip » as if to grasp a can, or ”key grip », as if to grasp a credit card between the thumb and other fingers.
The device uses multi-contact epineural electrode cuffs, each with several contacts points that can be activated independently. For the study, these were wound around the median and radial nerves above the elbow to allow them to stimulate different nerve fibers depending on the chosen points of contact, thus selectively and synergically activated muscle groups. They were controlled by an external stimulator which was piloted by the patient through an intuitive interface. Neurinnov’s technique was easy to implement, with patients rapidly gaining not only hand gestures, but producing hand movements with a force, close to normal.
Patients determined the desired movement, using a shoulder as a joystick to activate the corresponding stimulation. For example, lifting, lowering, moving the shoulder forward or backward could trigger different hand opening and closings.
The study’s significant achievement is strongly indicative of the high-performance of Neurinnov’s ASIC neurostimulation platform that has solved many of the drawbacks of traditional tendon-surgical or external neuromuscular stimulation approaches.
Participating partners in the Agilis project led by Inria include: APHP Hospital, CorTec, Centre Bouffard Vercelli (Perpignan), Clinique Saint Jean (Montpellier) and Neurinnov.