Article

More than 150 000 neuroprostheses (NPs) have been implanted in
people to restore bodily function in a variety of neural disorders. The authors
developed a novel NP, the Stimulus Router System (SRS), in which only passive
leads are implanted. Each lead picks up a portion of the current delivered
through the skin by an external stimulator. OBJECTIVE: . The authors report on
the first human implant of an SRS. METHODS: . The recipient was a tetraplegic man
with bilateral hand paralysis. Three SRS leads were implanted in his right
forearm to activate the finger extensors, finger flexors, and thumb flexor. A
wristlet containing a surface stimulator and electrodes was used to pass trains
of electrical pulses through the skin to each lead. Hand opening and grasp were
controlled via a wireless earpiece that sensed small tooth-clicks and transmitted
signals to the wristlet. RESULTS: . The current required to activate the muscles
was less than half that required prior to implantation and below perceptual
threshold. Maximal grip force and hand opening aperture were both larger using
the SRS. The implanted leads have remained functional for 3 years. The recipient
reported various tasks of daily life that improved during SRS usage. An
electronic counter revealed mean monthly usage of 18.5 hours, equivalent to 55
hours of continuous manual activity. CONCLUSIONS: . This first implant of the SRS
indicates that it can be effective and reliable and has potential to provide an
alternative to existing NPs.

Langue : ANGLAIS