Low-Cost Photoacoustic Imaging System for Vascular Occlusion Detection in Polymer Phantoms

Introduction: Vascular occlusion is a chronic condition that impairs blood flow to vital organs. This study developed a novel, low-cost photoacoustic imaging (PAI) system that utilizes phantom modeling to detect this condition. In this study, vascular occlusion was modeled using polyvinyl chloride-dioctyl terephthalate phantoms, which were categorized into healthy and occluded types. Methods: The PAI system comprised an 808-nm laser diode as the radiation source, a condenser microphone as the detector, and a mechanical stage for sample scanning. The PAI system utilized a modulated continuous-wave diode laser, operating at a frequency of 14 kHz and a 50% duty cycle. Results: Acoustic intensity analysis revealed that healthy vasculature consistently generated more intense signals than occluded vasculature. At a depth of 1 mm, the average intensities were 76.3 dB (healthy) and 65.2 dB (occluded), which decreased to 46.2 dB and 22.1 dB, respectively, at a 5-mm depth. Because of these differences, the contrast ratio between healthy and occluded regions ranged from 1.4 to 6.6 dB. Furthermore, the signal-to-noise ratio in healthy samples was measured at 16.1 dB (1 mm depth) and 3.2 dB (5 mm depth). Conclusion: This study demonstrates that a simple PAI system can distinguish between healthy and occluded vasculature.