Development Of A High-speed Optical/acoustic Dual-modality Imaging System In Blood Vessels

The death of residents caused by cardiovascular diseases is a serious challenge facing our country presently.Acute cardiovascular events are mostly caused by the formation of thrombus caused by the rupture of vulnerable plaque in coronary arteries.Therefore,achieving accurate judgment and early warning of plaque vulnerability is one of the keys to reducing cardiovascular disease mortality.In medicine,imaging diagnostic techniques for plaques are widely researched and applied,including various non-invasive and interventional imaging methods.Non-invasive imaging methods include electronic computed tomography,magnetic resonance imaging,and positron emission computed tomography.Interventional imaging methods include intravascular ultrasound and intravascular optical coherence tomography.Although the various imaging methods have their own advantages,they all have certain limitations.In recent years,the emerging intravascular photoacoustic imaging technology has received extensive attention is an effective imaging method for detecting vulnerable plaque.Photoacoustic imaging has the characteristics of high imaging resolution,large imaging depth and high contrast,making up for many limitations of other imaging technologies.But in order to push it to the clinic,the current intravascular photoacoustic imaging technology needs to further increase its imaging speed and design corresponding software and hardware systems.In the existing photoacoustic endoscopy research,the imaging speed is an important limiting factor.The existing photoacoustic endoscopy system can only achieve an imaging speed of 25 frames per second,and cannot fully meet the clinical diagnostic needs.The research purpose of this subject is to build a high-speed photoacoustic imaging control system suitable for intravascular.When using the photoacoustic endoscopic imaging system to perform in vivo blood vessel imaging,the imaged part needs to be flushed to ensure that the probe can effectively collect the information of the blood vessel wall.In actual clinical applications,the shorter the scouring time in the imaging process,the better,which means that the system acquisition and imaging speed need to be increased.The control system researched and built in this subject can collect photoacoustic signals at high speed,and the highest imaging speed can reach 100 frames per second.The research significance of this subject is to use the built-up high-speed photoacoustic imaging system to solve the bottleneck problem of the previous photoacoustic imaging speed.In view of this,the main research contents of the photoacoustic / ultrasound dual-mode intravascular imaging system are as follows:(1)Hardware design: The optical components,acoustic components,and motion control module devices have been designed and customized to realize a set of hardware systems that can be used for intravascular imaging.(2)Software design: Due to the need for high-speed acquisition and imaging,higher requirements are placed on the system software part.This paper adopts the producer / consumer model and maximizes the ability of the development workstation to achieve real-time data on the software display.Experiments show that the system software can reach the clinical level in real-time imaging.(3)Verification of imaging ability: The real-time imaging function of the system was verified through experiments on intravascular stents.In vivo experiments were carried out on live rabbits to verify the feasibility of the system.