【摘要】 为提高电阻抗成像数据采集系统的信噪比并且简化硬件电路设计,提出了一种基于Walsh函数的最优电流激励模式。利用Walsh电流对敏感场域进行激励,测量其电压响应,借助统计线性回归求解阻抗矩阵并将最优激励模式下的电压响应表示为Walsh电压响应的线性组合。结合正则化Gauss-Newton法重建阻抗图像。仿真结果表明,Walsh函数最优电流激励模式可以改善硬件系统的抗噪声能力,并且保证整个敏感场域内电流密度分布的均匀性。结合最优电流激励模式进行图像重建,提高了重建算法的收敛速度及重建图像的质量。更多还原

【Abstract】 An optimal excitation current pattern was developed based on Walsh function for electrical impedance tomography to improve the signal-to-noise ratio of the data acquisition system and simplify the hardware design.The system applies Walsh excitation current to the sensitive field and measures the voltage response to construct a resistance matrix.The system then synthesizes the voltage response to the optimal current pattern from the voltage responses to Walsh current. The optimal current pattern strategy uses the regularized Gauss-Newton method to reconstruct the interior resistivity distribution.Simulations indicate that Walsh current pattern method reduces the noise in the hardware system and guarantees uniformity of the current density distribution.Reconstruction algorithms using the optimal current pattern will have improved convergence and improved reconstructed image quality.更多还原