A new type of sensor based on optical fibers offers advantages, including low cost, high sensitivity, and small size. The sensors have already been used to monitor the curvature of structures and robotic arms. But measuring both the magnitude and direction of the spine’s curvature presents an additional challenge — one that the team overcame through innovative design.
In the proposed optical fiber sensor, input of light travels through three fiber cores. The operating principle of the sensor is based on the concept of what is called wavelength modulation. When an optical fiber is bent, the structure of the fiber core’s material changes, altering its density. In turn, this modifies the refractive index of the core, and the wavelength of the output light changes depending on how much the fiber was bent.
By constructing calibration tables, the magnitude of the spine’s curvature can be estimated based on the difference between the wavelengths of the input and output light in a single core.
One significant advantage of the fiber is that it shows linear results in the output. The new optical fiber sensor could pave the way for a new method of measuring the curvature of the different sections of the spine.
For more information, visit here .