Detection and identification of solid emboli and gas emboli in simulated blood using ultrasonic doppler

Emboli in high-speed circulated blood flow can be divided into solid and gas types, which easily get stuck on the blood vessel wall and cause blockage. Accurate detection of emboli can provide reliable information for early diagnosis, prevention, and treatment of cerebrovascular diseases. A Developed Ultrasonic Doppler Identification (DUDI) method is used to detect emboli of different types. Using a comparative investigation of differences between the interface intensity reflectivity of emboli and red blood cells, Doppler amplitudes extracted from echo signals were analyzed based on auto-correlation technology to achieve the extraction of embolic characteristics. Nylon particles, diatom particles, and bubbles were used to simulate red blood cells, solid embolism, and gas embolism, respectively, as the experimental objects. The Doppler amplitude data of the above three types were statistically analyzed to obtain the probability density function of them, Doppler amplitude thresholds were determined due to distribution characteristics of the probability density function. By combining the velocity distribution and Doppler amplitude of three objects, emboli, and red blood cells were classified to achieve the detection of emboli. The research results have shown that the DUDI method cannot only simultaneously identify solid embolism, gas embolism, and red blood cells but also achieve real-time measurement, which is of great significance for the identification of embolism in medical practice.