Fig. 6: Viability in human clinical settings.
a–d In vitro tests of the device navigability and electrode delivery in a human venous system model. The device smoothly reached the vascular areas near the visual cortex (a), the foot and hand area of the motor cortex (b and c), and the ventral striatum (d). The device penetrated the vessel wall at the desired location (indicated by green boxes) and delivered uFINE-Is to the target brain region (indicated by the orange shaded area). Red dashed lines in the leftmost column indicate intravascular paths. Magenta dashed lines outline balloon catheters. Yellow dashed lines indicate vascular axes. Green dashed lines indicate penetration directions. Yellow arrows indicate puncture angles. Magenta boxes indicate where the uFINE-I should be inserted in the target brain region. SS, straight sinus. Schematic diagrams were created based on ref. 64 e HE staining of the cross section of the femoral vein in rats, showing the endothelialization of uFINE-Is at 3 months after implantation. The black dashed line marks the intima in the magnified view. Scale bars, 100 and 50 µm. f The cross-sectional area of the endothelialized uFINE-I in the rat vein after 3-month implantation (0.0117 ± 0.0010 mm2, n = 30 slices, mean ± SD). Boxed plot: the 25th, 50th (median), and 75th percentiles of the data are indicated. The whiskers represent mean ± 1.5 SD. g Schematic diagram showing the cross-sectional size of uFINE-I relative to human veins.
