Evaluation of Tensile Force in a Porcine Trachea Using a Reflective Optical Method

The trachea serves a variety of functions during breathing and swallowing. In cases requiring a partial resection, the treatment may involve anastomosis of the healthy ends of the trachea. The tension in the anastomosis should not exceed 1,000？g. Traditional methods for estimating tension in the trachea are very invasive. The aim of this work is to develop a noninvasive optical system devoted to estimate the tension of the trachea in vivo. An optical system was designed using a light source and a photosensor. To determine the most suitable wavelength for the light source, a photoacoustic spectroscopy study was performed. 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