一种基于新型传感器的脑出血磁感应相位移检测系统

Magnetic induced phase shift detection system based on a novel sensor for cerebral hemorrhage

目前基于磁感应相位移技术检测系统的激励线圈产生的主磁场大多为分散场,场强小且抵消效果有待进一步改善,使得检测信号较弱,检测系统难以实现定量检测,阻碍了该技术用于活体实验和临床试验。为改善上述问题,本研究提出了一种新的亥姆霍兹鸟笼传感器。设计仿真实验从磁场强度和磁场分布两方面分析主磁场,设计不同出血体积和出血速率实验并与传统传感器进行对比评估。结果显示与传统线圈相比,检测目标所在区域磁场强度增大2.5倍,实现了主磁场抵消,10 mL兔血测得的相位差幅值达(–3.34±0.21)°,相位差与出血体积和速率指数拟合调整后R2均达到0.99。本文提出的亥姆霍兹鸟笼传感器具有场强更高的均匀磁场,能够更加精确地定量检测出血量,并且可以监测出血速率的改变,对磁感应技术用于脑出血检测研究具有重要意义。

The main magnetic field,generated by the excitation coil of the magnetic induction phase shift technology detection system,is mostly dispersed field with small field strength,and the offset effect needs to be further improved,which makes the detection signal weak and the detection system difficult to achieve quantitative detection,thus the technology is rarely used in vivo experiments and clinical trials.In order to improve problems mentioned above,a new Helmholtz birdcage sensor was designed.Stimulation experiment was carried out to analyze the main magnetic field in aspects of intensity and magnetic distribution,then different bleeding volume and bleeding rates experiments were conducted to compared with traditional sensors.The results showed that magnetic field intensity in detection region was 2.5 times than that of traditional sensors,cancellation effect of the main magnetic field was achieved,the mean value of phase difference of 10 mL rabbit blood was(-3.34±0.21),and exponential fitting adjusted R?between phase difference and bleeding volumes and bleeding rates were both 0.99.The proposed Helmholtz birdcage sensor has a uniform magnetic field with a higher field strength,enable more accurate quantification of hemorrhage and monitored change of bleeding rates,providing significance in magnetic induced technology research for cerebral hemorrhage detection.