Keshtkar A, Keshtkar A
Medical Physics Department, Medical Faculty, Tabriz University of Medical Sciences, Tabriz, Iran.
J Med Eng Technol. 2008 Nov-Dec;32(6):505-11. doi: 10.1080/03091900701507456.
There are a number of studies using electrical impedance spectroscopy, a minimally invasive technique, as a tissue characterizing method with different probe sizes (usually with larger probe diameters than that used in this work). In urinary bladder studies the probe size are limited to 2 mm diameter, in order to pass through the working channel of the cystoscope to measure the impedance inside the urinary bladder. Thus, bio-impedance of the human urothelium can only be measured using a small sized probe for in vivo studies. Different pressures were applied with this probe and it was demonstrated that increasing the applied pressure over the probe would increase the measured electrical impedance of the bladder tissue. Therefore, the effect of applied pressure on the resulting electrical impedance was considered in this study (all of the measurements were taken on points that had benign histology). An excessive amount of the applied pressure beyond the first visible indentation (first recordable reading) pressure has a significant effect on the impedance of the bladder tissue (p < 0.001). Then, to reduce the effect of pressure on the measured bio-impedance, the effect of a larger probe (10 mm diameter) was considered (p < 0.001). Increasing the probe contact area is one way to reduce the pressure effect on measurements; however this is difficult in practice in the in vivo situation.
有许多研究使用电阻抗光谱法（一种微创技术）作为一种组织表征方法，这些研究使用的探头尺寸各不相同（通常探头直径比本研究中使用的更大）。在膀胱研究中，探头尺寸限制为直径2毫米，以便通过膀胱镜的工作通道来测量膀胱内部的阻抗。因此，在体内研究中，只能使用小尺寸探头来测量人体膀胱上皮的生物阻抗。对该探头施加了不同的压力，结果表明，增加探头所施加的压力会增加所测量的膀胱组织电阻抗。因此，本研究考虑了施加压力对所得电阻抗的影响（所有测量均在组织学为良性的点上进行）。施加的压力超过首次可见压痕（首次可记录读数）压力过多，会对膀胱组织的阻抗产生显著影响（p < 0.001）。然后，为了减少压力对所测量生物阻抗的影响，考虑了使用更大探头（直径10毫米）的影响（p < 0.001）。增加探头接触面积是减少压力对测量影响的一种方法；然而，在体内情况下，这在实践中很难做到。
