Department of Biomedical Engineering, Amirkabir University of Technology, 15875-4413, Tehran, Iran.
Department of Thoracic Surgery, Tracheal Diseases Research Center (TDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Ann Biomed Eng. 2018 Aug;46(8):1079-1090. doi: 10.1007/s10439-018-2032-8. Epub 2018 Apr 23.
Identifying and localizing of deep pulmonary nodules are among the main challenges that thoracic surgeons face during operations, particularly in thoracoscopic procedures. To facilitate this, we have tried to introduce a non-invasive and safe method by measuring the lung electrical bio-impedance spectrum with a four-electrode array sensor. To study the feasibility of this method, since any change in the depth or diameter of the nodule in the lung tissue is not practical, we used the finite element modeling of the lung tissue and pulmonary nodule to allow changes in the depth and diameter of the nodule, as well as the distance in between the injection electrodes. Accordingly, a bio-impedance sensor was designed and fabricated. By measuring the electrical impedance spectrum of pulmonary tissues in four different specimens with a frequency band of 50 kHz to 5 MHz, 4 pulmonary nodules at four different depths were identified. The obtained bio-impedance spectrum from the lung surface showed that the magnitude and phase of electrical bio-impedance of the tumoral tissue at each frequency is smaller than that of the healthy tissue. In addition, the frequency characteristic varies in the Nyquist curves for tumoral and healthy lung tissues.
识别和定位肺部深处的结节是胸外科医生在手术中面临的主要挑战之一，尤其是在胸腔镜手术中。为了便于操作，我们尝试引入一种非侵入性和安全的方法，即用四电极阵列传感器测量肺部的生物电阻抗频谱。为了研究该方法的可行性，由于肺组织中结节的深度或直径的任何变化都不切实际，我们使用肺部组织和肺部结节的有限元建模来允许结节的深度和直径以及注射电极之间的距离发生变化。因此，设计并制造了生物阻抗传感器。通过在四个不同的样本中测量频率范围为 50kHz 至 5MHz 的肺组织的电阻抗频谱，在四个不同的深度处识别出了四个肺结节。从肺表面获得的生物电阻抗频谱表明，每个频率下肿瘤组织的电阻抗的幅度和相位都小于健康组织。此外，肿瘤和健康肺组织的奈奎斯特曲线中的频率特性也不同。
