为实现可用于临床乳腺普查的电阻抗成像硬件系统,从临床普查角度出发分析硬件系统的设计要求,进行基于平板电极阵列方式的阻抗扫描成像硬件系统设计。建立了一个多频电阻抗扫描硬件系统,经定标电阻网络对系统的性能进行了评估,激励源输出幅值为1.0V时,幅度信噪比为80dB,相位噪声0.005°;相应采集信号幅度信噪比为60dB,相位噪声0.05°。系统可以识别1%的阻抗变化。物理模型实验表明,系统可识别2mm×2mm×2mm的高电导率目标体。硬件系统精度高,模型实验证明本系统满足临床乳腺检测的需要,但要在临床实验中进一步验证。
Objective: to implement an electrical impedance imaging system for clinical breast screening. Method: from the aspect of clinical screening, the design requirements of the hardware system are analyzed. An electrical impedance scanning (EIS) hardware system using plane electrode array was designed. Result: a multi-frequency EIS hardware system was setup and was assessed using calibration resistance network. For 1.0V output of the stimulating source, the amplitude-SNR is about 80 dB and the phase-noise is about 0. 005 °. Correspondingly, the amplitude- SNR of the measured signal is 60 dB, and its phase-noise is about 0.05 °. In one-frame measured data, 1% impedance difference could be detected by the system. A 2 mm × 2 mm × 2 mm-target with a higher conductivity could be detected in a physical phantom experiment. Conclusion: the hardware system features high performance, physical phantom experiment demonstrates that the system meets the requirement of clinical breast detection; but it still needs to be validated in clinical experiment.