A Repetitive Transcranial Magnetic Stimulation-Functional Near-Infrared Spectroscopy System: Achieving Dynamic...

Objective: This study aimed to integrate repetitive transcranial magnetic stimulation (rTMS) with functional near-infrared spectroscopy (fNIRS) to achieve concurrent monitoring of neural activity during neuromodulation and to evaluate its feasibility in stroke rehabilitation. Impact Statement: This work addresses the long-standing lack of concurrent feedback in stroke neuromodulation and provides an important pathway for developing adaptive, closed-loop neurorehabilitation technologies. Introduction: The application and optimization of rTMS in stroke rehabilitation are constrained by the absence of concurrent physiological feedback, which limits timely evaluation of stimulation efficacy and adjustment of treatment parameters. Existing techniques combining neuromodulation with neuroimaging often lack validation, hindering their clinical translation and widespread application. Methods: This study employed improved fNIRS probes to construct an rTMS-fNIRS system capable of proximal detection under routine clinical rTMS conditions. Magnetic interference testing and simulation analyses were performed to evaluate system artifacts, field penetration, and focality. A 14-d clinical trial was conducted to verify the system's feasibility and effectiveness. A total of 80 patients with stroke were enrolled, and wavelet amplitude and laterality index were used to quantify neuroplasticity changes while clinical scales were applied to assess behavioral improvements. Results: Engineering validation demonstrated that the system stably recorded cortical hemodynamic responses under high-intensity stimulation. Concurrent clinical monitoring revealed that excitatory rTMS induced dynamic enhancement of cortical activation and interhemispheric rebalancing, and these neurophysiological changes were significantly correlated with improvements in upper-limb motor recovery. Conclusion: The proposed rTMS-fNIRS system not only provides stable neuromodulatory intervention but also enables concurrent monitoring of stimulation-induced neuroplastic changes under clinical conditions.