在呼吸和吞咽时，气管有多种功能。在需要部分切除的情况下，治疗可能包括吻合气管的健康端。吻合口张力不应超过1000克。传统的评估气管张力的方法是有创性的。这项工作的目的是开发一种用于估计气管张力的无创光学系统
体内。一种光学系统，是使用光源和光传感器的设计。以确定用于所述光源的最合适的波长，进行了光声光谱研究。To test the system, a cadaveric pig trachea was mounted on a universal testing machine, and it was subjected to three tensile tests of up to 30 mm elongation. The optical response was measured at 0, 10, 20, and 30 mm elongation. An exponential response was observed so that the optical voltage-response curves were adjusted, and three exponential equations were derived to correlate the voltage with the optical response. We can conclude that the proposed optical system is able to noninvasively estimate the tension of a cadaveric porcine trachea.
光声光谱学允许我们确定具有最小光吸收的入射光的波长[
10]。待研究样品被放置在一个封闭的圆柱形金属容器中，容器上覆盖着石英窗，以减少对紫外线或红外光的吸收。入射光被调制到一个固定的频率，
f(17 Hz), by a rotating disk having a radial groove (chopper). Light enters the cell at the top, and a microphone is placed laterally, as shown in Figure
1。数字
2显示了用于光声研究的实验设备。
得到没有明显的疾病的年轻成年猪尸体气管的样品。将样品4小时获得样品，在此期间它被保存在生理溶液中测试。对应于纤维软骨管段被保存;肺，气管隆突，食管，环状软骨和甲状软骨被拆除。The testing length, in this case the distance between supports, was 100 mm. A universal Instron testing machine model 4502 (Instron Corp, Norwood, MA, USA) was used at a constant speed of 20 mm/min from 0 to 30 mm elongation. Optical equipment was mounted next to the test machine, and the optical response of the sample was recorded at 0, 10, 20, and 30 mm elongation (Figure
4)。用相同的试样和相同的实验装置进行了三次拉伸试验和光学响应测量。
测试在万能试验机气管的安排。
3.结果
小组织样本从两个尸体猪气管和安装在光声细胞。利用上述光声光谱仪设备，确定了它们的光吸收光谱随波长的变化。观察到，光吸收在较低的波长较高，并逐渐渐近地减少(图)
5)。We observed that there are high peaks in the absorption measured after 700 nm, so we chose a wavelength of 650 nm, which corresponds to the red color.
两具猪尸体气管样品在不同波长下的吸光度测定。
使用这种波长，这是可能的，以便测量气管张力来选择用于光学系统中的光电传感器适合。We selected the TSL 257 phototransistor (ams AG, Premstaetten, Austria), which operates at wavelengths between 300 and 1,100 nm and temperatures between 0 to 70°C.
表格
1shows the load results obtained from the tension test with the values measured by the optical system at 0, 10, 20, and 30 mm of elongation (equivalent to 0%, 10%, 20%, and 30%). Note that the curves have a nonlinear behavior. An exponential (allometric) nonlinear adjustment was made using Origin software version 8.0 (Origin Lab Corp., Northampton, MA, USA), as shown in Figure
7。得到以下方程:
(1)
Y
=
95.76
∗
X
0.0481
,
为
T
1
Y
=
96.24
∗
X
0.0357
,
为
T
2
,
Y
=
95.91
∗
X
0.0356
,
为
T
3.
气管是履行多种功能软骨环形成的解剖结构。如果一段被删除，重建气管的最简单的方法是气管的健康两端吻合。气管的延伸限制了该技术的使用，因为在吻合过大的张力会导致分离或狭窄。It has been established that the tension should not exceed 1,000 g at the ends subjected to anastomosis. Estimating tension on the trachea is usually done by
体外尸体标本的破坏性试验[
11,
12]。在目前的工作中，光学系统被设计成非侵入性地测量在气管中的张力，从而允许所提出的系统以潜在地在临床环境中使用。