Department of Medical Informatics, School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0373, Japan.
J Clin Monit Comput. 2010 Oct;24(5):363-70. doi: 10.1007/s10877-010-9255-z. Epub 2010 Aug 10.
Serious accidents during hemodialysis such as an undetected large amount of blood loss are often caused by venous needle dislodgement. A special plastic optical fiber with a low refractive index was developed for monitoring leakage in oil pipelines and in other industrial fields. To apply optical fiber as a bleeding sensor, we studied optical effects of soaking the fiber with liquids and blood in light-loss experimental settings.
The non-cladding optical fiber that was used was the fluoropolymer, PFA fiber, JUNFLON™, 1 mm in diameter and 2 m in length. Light intensity was studied with an ordinary basic circuit with a light emitting source (880 nm) and photodiode set at both terminals of the fiber under certain conditions: bending the fiber, soaking with various mediums, or fixing the fiber with surgical tape. The soaking mediums were reverse osmosis (RO) water, physiological saline, glucose, porcine plasma, and porcine blood. The light intensities regressed to a decaying exponential function with the soaked length.
The light intensity was not decreased at bending from 20 to 1 cm in diameter. The more the soaked length increased in all mediums, the more the light intensity decreased exponentially. The means of five estimated exponential decay constants were 0.050±0.006 standard deviation in RO water, 0.485±0.016 in physiological saline, 0.404±0.022 in 5% glucose, 0.503±0.038 in blood (Hct 40%), and 0.573±0.067 in plasma. The light intensity decreased from 5 V to about 1.5 V above 5 cm in the soaked length in mediums except for RO water and fixing with surgical tape.
We confirmed that light intensity significantly and exponentially decreased with the increased length of the soaked fiber. This phenomena could ideally, clinically be applied to a bleed sensor.
在血液透析过程中，如静脉针脱落导致大量未检测到的血液丢失等严重事故时有发生。一种低折射率的特殊塑料光纤已被开发用于监测输油管道和其他工业领域的泄漏。为了将光纤用作出血传感器，我们在光损耗实验设置中研究了光纤浸泡在液体和血液中的光学效应。
所使用的无包层光纤是直径为 1 毫米、长 2 米的氟聚合物 PFA 光纤 JUNFLON™。在一定条件下，使用带有发光源（880nm）和光电二极管的普通基本电路研究光强，这些条件包括光纤弯曲、用各种介质浸泡或用手术胶带固定光纤。浸泡介质为反渗透（RO）水、生理盐水、葡萄糖、猪血浆和猪血。光强随浸泡长度呈指数衰减函数回归。
在直径从 20 毫米弯曲至 1 厘米的过程中，光强没有降低。在所有介质中，浸泡长度增加得越多，光强的指数衰减就越大。在 RO 水中，五个估计的指数衰减常数的平均值为 0.050±0.006 标准差，在生理盐水中为 0.485±0.016，在 5%葡萄糖中为 0.404±0.022，在血液（Hct 40%）中为 0.503±0.038，在血浆中为 0.573±0.067。在除 RO 水和用手术胶带固定外，在介质中浸泡长度超过 5 厘米时，光强从 5V 降低到约 1.5V。
我们证实，光强随浸泡光纤长度的增加而显著呈指数衰减。这种现象在临床上可以理想地应用于出血传感器。
