论文部分内容阅读
基于磁声耦合效应的生物组织电特性检测成像方法,在神经电活动监测和肿瘤等疾病早期诊断方面具有重要研究意义。常用的单脉冲激励和接收模式的信噪比低,限制了磁声成像质量;信号平均处理方法则限制了成像速率。本研究提出了一种脉冲编码激励的磁声成像信号处理方法,采用编码序列激励模式和脉冲压缩的检测处理方法以提高信噪比,缩短信号处理时间。本研究通过仿真计算和磁声信号的实验测量,采用13位巴克(Barker)编码和16位格雷(Golay)编码,对磁声信号的编码激励和脉冲压缩处理方法进行了研究。结果表明,对金属丝模型,在未进行波形叠加平均的条件下,编码激励可明显提高磁声信号信噪比,如13位Barker脉冲编码和16位Golay编码处理方法,可分别提高磁声信号信噪比约20.96 dB和20.62 dB。同时处理时间明显缩短:在相同信噪比提升的情况下,13位Barker编码和16位Golay编码处理方法的整体采集处理时间约缩短为单脉冲激励平均处理方法的3.62%和4.73%。本研究提出的脉冲编码处理方法,对提高磁声信号信噪比、改善成像质量、提高整体成像速率具有重要意义。
Magnetic resonance imaging based on biological characteristics of tissue imaging detection methods in the neural activity monitoring and early diagnosis of cancer and other diseases has important research significance. The commonly used single-pulse excitation and reception modes have low signal-to-noise ratio, which limits the quality of magneto-acoustic imaging. The average signal processing method limits the imaging rate. In this study, we propose a pulse code excitation magneto-acoustic imaging signal processing method, using the code sequence excitation mode and pulse compression detection processing method to improve the signal-to-noise ratio and shorten the signal processing time. In this study, the coding excitation and pulse compression processing of the magneto-acoustic signal are studied by simulation calculation and experimental measurement of magnetoacoustic signals. The 13-bit Barker coding and 16-bit Golay coding are used in this study. The results show that the coding excitation can improve the signal-to-noise ratio of the magneto-acoustic signal obviously when the wire model is not averaged. For example, the 13-bit Barker pulse coding and the 16-bit Golay coding method can increase the magnetoacoustic signal SNR of about 20.96 dB and 20.62 dB. At the same time, the processing time is significantly shortened: the overall acquisition and processing time of the 13-bit Barker coding and 16-bit Golay coding methods is shortened to 3.62% and 4.73% of the single-pulse excitation averaging method under the same SNR. The pulse code processing method proposed in this study is of great significance to improve the signal-noise ratio of the magneto-acoustic signal, improve the imaging quality and improve the overall imaging rate.