基于DDS的超声诊断仪频率自动跟踪方法研究

Research on frequency automatic tracking method of ultrasonic diagnostic instrument based on DDS

为了提高超声诊断仪频率的自动跟踪检测性能,提出一种基于DDS的超声诊断仪频率自动跟踪方法。采用传感信号检测方法进行超声诊断仪的输出信号监测,在超声诊断仪的传输信道模型进行诊断信号的多传感器融合跟踪滤波处理,采用级联相关匹配滤波器进行超声信号的色噪声干扰抑制,提取超声诊断信号的频谱特征量,根据频谱分量在频域中的聚焦性能进行频域跟踪定位,采用离散控制器(DDS)实现超声诊断仪频率自动跟踪和状态监测,采用最大似然估计方法实现对超声诊断仪频率参量的自动估计。仿真结果表明,采用该方法进行超声诊断仪频率自动跟踪的准确性较高,对超声诊断仪频率检测的离散控制性能较强,提高了超声诊断仪的频率分辨力,参量估计误差较低。

In order to improve the automatic tracking performance of ultrasonic diagnostic instrument,an automatic frequency tracking method based on DDS is proposed.The sensor signal detection method is used to monitor the output signal of the ultrasonic diagnostic instrument,and the multi-sensor fusion tracking filter is processed in the transmission channel model of the ultrasonic diagnostic instrument.A cascade correlation matching filter is used to suppress the color noise interference of ultrasonic signal,and the spectrum characteristic of ultrasonic diagnosis signal is extracted,and the frequency domain tracking location is carried out according to the focusing performance of spectrum component in frequency domain.The frequency automatic tracking and state monitoring of ultrasonic diagnostic instrument is realized by discrete controller(DDS),and the frequency parameter of ultrasonic diagnostic instrument is estimated automatically by using maximum likelihood estimation method.The simulation results show that the accuracy of frequency automatic tracking of ultrasonic diagnostic instrument is high,the discrete control performance of frequency detection of ultrasonic diagnostic instrument is better,the frequency resolution of ultrasonic diagnostic instrument is improved,and the error of parameter estimation is low.