【摘要】 为了补偿医学超声内窥镜中超声信号的传输衰减,设计了由AD8065、AD8331和现场可编程门阵列(FPGA)组成的前置放大与增益补偿电路.电路采用AD8065实现超声换能器与增益补偿电路间的阻抗变换,然后,根据超声信号在人体组织中的衰减规律,由FPGA输出补偿控制电压,控制AD8331实现对回波信号的补偿放大.对实际超声回波进行的补偿实验表明,该电路能够有效地补偿超声信号的传输衰减,而且,利用FPGA的可编程性,该电路可根据不同的衰减曲线进行灵活配置.更多还原

【Abstract】 In order to compensate the propagation attenuation of the ultrasonic signal in the medical ultrasonic endoscope, an amplified and time gain compensation(TGC)circuit was designed which consisted of AD8065,AD8331 and field programmable gate array(FPGA). In the circuit the AD8065 was utilized to match the impedance between the ultrasonic transducer and TGC circuit. Then,according to the attenuation curve of the ultrasonic signal in the human tissue,the FPGA output a control signal to drive the AD8331 to compensate the echo. The performance was validated by the experiment of compensating the echoes. Furthermore,with the programmability of the FPGA,the circuit could be configured differently for variant attenuation curves.更多还原