Next-Generation Non-Invasive Capillary Angiography System

Background Imaging capillary blood flow and tissue oxygenation is critical for conditions such as diabetes, cardiovascular diseases, flap monitoring, and cancer. Existing imaging modalities are invasive, lack real-time resolution, or require contrast agents. Methods We designed a Next-Generation Non-Invasive Capillary Angiography System using dual-wavelength near-infrared illumination (~ 730 nm and ~ 850 nm) and an infrared-sensitive camera. Differential absorption between oxy- and deoxyhemoglobin was analyzed via custom software incorporating preprocessing, alignment, vessel segmentation, and visualization modules. Preliminary benchtop experiments were performed on tissue phantoms and healthy volunteers. Results The system resolved vessels as small as 2 mm at 6 mm depth with 100% detection in phantom experiments. In vivo forearm imaging demonstrated successful visualization of superficial veins without contrast agents. Informal imaging of Raynaud’s phenomenon showed reduced perfusion during vasospasm and recovery upon rewarming. Acquisition time was < 2 s per frame pair, with projected real-time imaging rates of 10–30 fps. Conclusions The prototype successfully combines perfusion and oxygenation imaging in a single device, offering a safe, portable, and cost-effective alternative to conventional angiography. This system has potential applications in diabetic wound monitoring, reconstructive surgery, vascular disease, oncology, and point-of-care diagnostics.