Fig. 4: Bidirectional modulation of vasomotor dysfunction.

a Block diagram of the bidirectional system designed for detecting and modulating vasomotor dysfunction. b Photograph showing the implantation sites and functional roles of the two interfaces. c Optimization and selection of stimulation pulse current amplitude. d VE signals recorded by the BACE interface at the distal segment of the aorta in response to a series of stimulations with a charge-balanced current pulse (pulse amplitude: 300 μA, pulse width: 100 μs) immediately and 14 days after stent implantation. The timing of stimulation is indicated by red stars. e Extended monitoring of vasomotoricity over a prolonged period based on (d), incorporating three additional current stimulations. A close-up view highlights the steady-state VE signal following the cessation of stimulation. f Comparative analysis of normalized power across five states annotated in (d) from n = 3 rabbits. Data are presented as mean values ± SD. p values for power comparison: p = 0.0011 (State 1 vs. State 2), p = 0.0045 (State 1 vs. State 3), p = 0.0716 (State 1 vs. State 4), p = 0.9173 (State 1 vs. State 5). (ns: p > 0.05, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, One-way repeated measures analysis of variance). g Ultrasound color-flow imaging of the distal aorta, along with corresponding arterial stiffness parameters β before and after stimulation (with the corresponding states annotated), demonstrating the effectiveness of electrical modulation. Stim. in (d) and (g) denotes stimulation.