Technical And Experimental Research Of Blcoking Emboli In Blood Vessel By Phased Array Ultrasound System

Neurologic complications are common complications after cardiovascular surgery.Depending on condition,they are divided into stroke,cognitive impairment.Neurologic complication are hard to heal.It put hard economic and mental burden on patient and their family.The reason of neurologic complication is because emboli generated in cardiovascular surgery flow into cerebral vessel.Therefore,morbidity of neurologic complication will decrease if we can prevent emboli from flowing into cerebral vessel.How to prevent emboli form flowing into cerebral vessel effectively is a hard problem which is urgent to be solved.In order to prevent emboli from flowing into cerebral vessel,many traditional emboli blocking devices were developed.But most of those devices need to improve their performance.And they are expensive and hard to operate.In recent years,a new method of using ultrasound radiation force to block emboli is proposed.When fluid with foreign particles is radiated by ultrasound,foreign particles will suffer a force which make them float and assemble.Foreign particles will change their moving direction.When blood is radiated by ultrasound,emboli in blood will suffer ultrasound radiation force.Depending on this principle,we can use ultrasound radiation force to change emboli moving direction so that to block emboli.In our research,we do theoretical analysis on the factor which can influence the ultrasound radiation force intensity which emboli suffer in the ultrasound field.This provide theoretical basis for animal experiment.We develop and set up a platform of phased array ultrasound system which is used to do animal experiment.Parameter of phased array ultrasound,such as ultrasound period and precision of phase moving,is designed and set up through theoretical analysis.After test,the quality of phased array ultrasound achieve the requirement of animal experiment.And it provide technical support for research of animal experiment.We explore the blocking effect of phased array ultrasound on emboli through doing animal experiment.After analyzing the result of experiment,we found that phased array ultrasound have a good performance on blocking emboli.In the same environment,the blocking effect of phased array ultrasound on gaseous emboli is better than solid emboli.Through the animal experiment,we get the conclusion that phased array ultrasound is a safety and effective method to block emboli which have a significant meaning to decrease morbidity of neurological complications.