PMC9874950_01
Participant with unilateral transtibial limb loss using the sensory neuroprosthesis (SNP) to perform a task in which his vision is occluded. Sensors in his prosthesis shoe (right inset) transduce pressures applied to the prosthetic foot during walking, standing, or other activities. Sensor signals are sent wirelessly to an external neurostimulation system worn on the belt, which then sends neural stimulation to the sciatic and tibial nerves through chronically-implanted Composite Flat Interface Nerve Electrodes (C-FINEs) (left inset).
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F1
The sensor measured changes in pressure in the forefoot, midfoot, and heel (Figure 1). When the participant placed pressure on one of these areas of the prosthesis, stimulation was sent to the corresponding C-FINE channel, and the sensation was felt immediately on the corresponding location of the missing foot (Figure 1). The entire external assembly, including the sensorized prosthetic foot, neurostimulator, and associated cabling, constitute the lower limb SNP (Figure 1).
Study timeline. The total study covered a period of 291 days and was divided into three sections: Pre-active (29 days), Active (219 days), and Post-Active (43 days). Five interviews (denoted by blue dots) were conducted over the course of the study. One interview occurred at the beginning of the trial, two interviews occurred during the active phase, and two occurred during the post active phase.
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F2
The home study lasted 291 days and was comprised of three phases: Pre-Active (29 days), Active (219 days), and Post-Active (43 days) (Figure 2). Semi-guided interviews were conducted at five-time points throughout the study (Figure 2).