【摘要】 为了提高医学超声内窥镜系统的探测深度和成像质量,将广泛应用于雷达系统的编码激励技术引入到超声成像系统中,采用编码脉冲信号激励超声换能器,以增加超声发射功率,提高回波信号信噪比。在分析编码激励原理和超声换能器暂态工作特性的基础上,设计并实现了超声信号的4 bit Barker编码脉冲发射。实验中,激发电路输出的编码激励信号与超声换能器的暂态工作特性吻合;玻璃杯壁的反射超声回波信号,具备编码特征,与Matlab仿真结果相同,且幅度较强。更多还原

【Abstract】 In order to increase the detecting depth and imaging quality of the medical ultrasonic endoscope,we introduce the coded excitation into the ultrasonic imaging system,which is widely used in radar system.The ultrasonic transducer is driven by a coded pulse to increase the emission power and SNR of ultrasonic echo.The principle of coded excitation and the transient operating characteristic of ultrasonic transducer are analysed firstly.Then,we implement the coded pulse transmitting of ultrasonic signal.In the experiment,the coded excitation pulse outputed by the transmitting circuit is consistent with the transient operating characteristic of ultrasonic transducer.And the reflected ultrasonic echo from the glass possesses the character of 4-bit barker code,which is identical with the simulating result by Matlab.Furthermore,the signal′s amplitude is higher.更多还原