To prevent vessel damage and complications during brain biopsies, accurate real-time blood flow monitoring is crucial. This highlights the need for real-time, minimally invasive vascular monitoring without external contrast agents. Optoelectronic techniques, such as Laser Doppler Flowmetry (LDF) and fluorescence-based methods, show significant promise. While LDF is widely used, its effectiveness is limited by factors such as sensitivity to tissue properties, complex data interpretation, the need for precise probe placement, and susceptibility to motion artifacts. On the other hand, fluorescence-based methods exhibit low sensitivity when relying on natural fluorophores. This work introduces a novel fiber-optic system using LED illumination and photodiode detection. A silicone vein phantom, perfused with synthetic blood via a modulated pump, simulates pulsatile flow. Preliminary analysis employs lock-in detection to link pressure modulations with reflected light variations, enhancing the signal-to-noise ratio. Early results demonstrated effective blood perfusion detection at various distances, supporting safer, real-time vascular monitoring during brain biopsies.