DPSD在低场核磁共振回波信号检测中的应用

核磁共振回波信号幅度微弱，容易受到来自电子器件和外部环境噪声的干扰，要求回波检测方法既能实时采集回波数据，又能较好的抑制噪声. 对比分析不同微弱信号检测方法的优缺点，归纳出DPSD(Digital Phase-Sensitivity Detection)方法在回波检测应用中的优越性. 通过仿真计算， 提出适用于回波信号检测的最佳滤波器窗函数. 在自制的核磁共振仪器上进行实验，结果表明，DPSD方法在满足回波信号实时测量的同时，有效压制了噪声，能准确的提取出低场核磁共振回波信号的幅度和相位信息.

Application of DPSD to NMR Echo Train Detection at Low Field

In NMR logging,amplitude of NMR echo train is often weak,and vulnerable to noise contamination originated from either electronic devices or external environment.Both real-time acquisition and noise suppression are critical to echo envelope detection.In this paper,advantages and disadvantages of various echo envelope detection methods were reviewed.The superiority of DPSD(digital phase-sensitivity detection) for NMR echo detection was discussed.The optimal filter window function was obtained from simulation ...