Federal University of Technology-Paraná, CPGEI, Curitiba, Parana, Brazil.
Med Eng Phys. 2011 Apr;33(3):356-61. doi: 10.1016/j.medengphy.2010.11.001. Epub 2010 Dec 13.
Electrical impedance spectroscopy offers many applications in the medical field due the fast response, non-invasiveness and low cost. One promising area is the use of this method for diagnostics. This paper describes the design and experimental evaluation of a multifrequencial complex bioimpedance analyzer. Impedance amplitude and phase were calculated using Discrete Fourier Transform (DFT) and high frequency signals were measured with undersampling. The prototype was able to measure values from 1 Ω to 50 kΩ (frequency range from 50 Hz to 500 kHz). The accuracy of the technique was compared with a commercial equipment. The analysis of passive components resulted in a mean error of 2.9% for the magnitude and 0.69 degrees for the phase. Besides, an initial study for head and neck cancer detection through neural networks is shown. One used bioimpedance values as well as gender, age and body mass index as inputs. The network used 120 training and 40 validation data and was able to simulate 77.5% of the two types of diagnostic correctly.
由于响应速度快、非侵入性和成本低，电阻抗频谱分析在医学领域有许多应用。一个很有前途的领域是将这种方法用于诊断。本文介绍了一种多频复阻抗分析仪的设计和实验评估。使用离散傅里叶变换（DFT）计算阻抗幅度和相位，并采用欠采样测量高频信号。该原型能够测量 1 Ω 至 50 kΩ 的电阻值（频率范围为 50 Hz 至 500 kHz）。将该技术的准确性与商业设备进行了比较。对无源元件的分析结果表明，幅度的平均误差为 2.9%，相位的平均误差为 0.69 度。此外，还展示了通过神经网络进行头颈部癌症检测的初步研究。该研究将生物阻抗值以及性别、年龄和体重指数作为输入。网络使用了 120 个训练数据和 40 个验证数据，能够正确模拟 77.5%的两种诊断类型。
