Fig. 3: In vivo acute tests for characterization of wireless bioresorbable dual stimulators in a rodent model.

a Schematic illustration of the implantation location. Top: Placement of the device in the animal and wireless coupling to an external transmission (\({T}_{x}\)) coil. Bottom: Device with cuffs wrapped around the sciatic nerve (proximal cuff) and tibial nerve branch (distal cuff). Due to a transaction between the cuffs on the tibial nerve, the proximal cuff only stimulates the TA through the fibular nerve branch. The distal cuff uniquely stimulates the LG. R_x= receiver. \({T}_{x}\)= transmission. [Created with Biorender.com]. b Schematic illustration of the experimental design (top) and EMG signals from the TA and LG muscles for each case. Corresponding changes in CMAP amplitude (bottom). TA tibialis anterior, LG lateral gastrocnemius, CMAP compound muscle, action potential, SHAM no stimulation using a sham device model, PROX stimulation of only the proximal sciatic nerve, DUAL stimulation of both the proximal sciatic nerve and the distal tibial nerve. [Created with Biorender.com]. c Circuit and block diagrams of the wireless stimulation system. A resistor (R₃) facilitates measurements of the change in voltage between points 4 and 5 as a function of input voltage. d–g Voltage (d), current (e), and power (f) applied to the nerve, and (g) resistance of the nerve as a function of input voltage after nerve damage, as determined through in vivo tests. h Schematic illustration and modeling results for the magnetic inductive coupling between a \({T}_{x}\) coil and the R_x coils (left). Modeling results for the efficiency of power transfer as a function of the resistance of the nerve (R_nerves) (right). i, j Modeling results for the efficiency (i) and the reflection coefficient as a function of frequency (j) for various values of R_nerve.