Double nerve intraneural interface implant on a human amputee for robotic hand control.
OBJECTIVE
The principle underlying this project is that, despite nervous reorganization following upper limb amputation, original pathways and CNS relays partially maintain their function and can be exploited for interfacing prostheses. Aim of this study is to evaluate a novel peripheral intraneural multielectrode for multi-movement prosthesis control and for sensory feed-back, while assessing cortical reorganization following the re-acquired stream of data.


METHODS
Four intrafascicular longitudinal flexible multielectrodes (tf-LIFE4) were implanted in the median and ulnar nerves of an amputee; they reliably recorded output signals for 4 weeks. Artificial intelligence classifiers were used off-line to analyse LIFE signals recorded during three distinct hand movements under voluntary order.


RESULTS
Real-time control of motor output was achieved for the three actions. When applied off-line artificial intelligence reached >85% real-time correct classification of trials. Moreover, different types of current stimulation were determined to allow reproducible and localized hand/fingers sensations. Cortical organization was observed via TMS in parallel with partial resolution of symptoms due to the phantom-limb syndrome (PLS).


CONCLUSIONS
tf-LIFE4s recorded output signals in human nerves for 4 weeks, though the efficacy of sensory stimulation decayed after 10 days. Recording from a number of fibres permitted a high percentage of distinct actions to be classified correctly. Reversal of plastic changes and alleviation of PLS represent corollary findings of potential therapeutic benefit.


CONCLUSIONS
This study represents a breakthrough in robotic hand use in amputees.
Rossini
Paolo M
PM
Dept. of Neurology, University Campus Bio-Medico, Rome, Italy. p.rossini@unicampus.it
Micera
Silvestro
S
Benvenuto
Antonella
A
Carpaneto
Jacopo
J
Cavallo
Giuseppe
G
Citi
Luca
L
Cipriani
Christian
C
Denaro
Luca
L
Denaro
Vincenzo
V
Di Pino
Giovanni
G
Ferreri
Florinda
F
Guglielmelli
Eugenio
E
Hoffmann
Klaus-Peter
KP
Raspopovic
Stanisa
S
Rigosa
Jacopo
J
Rossini
Luca
L
Tombini
Mario
M
Dario
Paolo
P
D000328:Adult; D000673:Amputation, Traumatic / Q000150:complications; D000674:Amputees; D001186:Artificial Limbs; D003199:Computer Systems; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D006225:Hand; D006801:Humans; D007389:Internal-External Control; D008297:Male; D008475:Median Nerve / Q000503:physiopathology / Q000601:surgery*; D009068:Movement; D009412:Nerve Fibers; D009473:Neuronal Plasticity; D010591:Phantom Limb / Q000209:etiology / Q000503:physiopathology / Q000601:surgery; D012371:Robotics; D012677:Sensation; D050781:Transcranial Magnetic Stimulation; D014459:Ulnar Nerve / Q000503:physiopathology / Q000601:surgery*