Heyser R C, Hestenes J D, Rooney J A, Gammell P M, Le Croissette D H
Jet Propulsion Laboratory, California Institute of Technology, Pasadena 91109.
Ultrasonics. 1989 Jan;27(1):31-8. doi: 10.1016/0041-624x(89)90006-1.
A reflection mode proof-of-concept medical ultrasound imager based on time delay spectrometry has been developed and tested. The system uses a broad band swept-frequency signal operating up to 10 MHz. Signal processing using a fast Fourier transform (FFT) permits extraction of range information. The imager has a higher signal-to-noise ratio than pulse-echo systems which allows high resolution at greater depths. The time delay spectrometry (TDS) spread spectrum operates at lower peak intensities than pulse-echo and permits more control of the spectral content and amplitude of the signal. At present, the system is non-real time which degrades in vivo imaging because of averaging over several cardiac cycles and tissue movement.
一种基于时延光谱法的反射模式概念验证医学超声成像仪已被开发并测试。该系统使用高达10MHz的宽带扫频信号。利用快速傅里叶变换（FFT）进行信号处理可提取距离信息。该成像仪的信噪比高于脉冲回波系统，这使得在更大深度处能实现高分辨率。时延光谱法（TDS）扩频在比脉冲回波更低的峰值强度下运行，并允许对信号的频谱内容和幅度进行更多控制。目前，该系统是非实时的，由于在几个心动周期和组织运动上进行平均，这会降低体内成像质量。
