Placing sensors inside the body can allow researchers and clinicians to understand and treat a variety of medical conditions. But, while implanting a sensing device can be easy, having it stay in the body long enough to perform its task and then to be safely removed is a substantial challenge. Now a collaboration between researchers in Italy and Greece has embedded so-called “fiber Bragg gratings,” a type of device that reflects certain light wavelengths and that can be used as a sensor, inside of dissolvable optical fibers. The technology may allow for long-term monitoring of both biomechanical and chemical characteristics of various organs and anatomical features inside the body.
These days fiber Bragg gratings inside of optical fibers are used to measure stresses placed on bridges, commercial airliner wings, and other areas where detailed, real-time monitoring is important. The newly developed fiber Bragg gratings are able to break down, much like absorbable sutures, and because they have been embedded into fiber optics that are themselves bioresorbable, they should be safe for use inside the body. Ideally, they would be implanted and then left inside the body to perform sensing tasks, eventually disappearing altogether and not requiring excisions.
The researchers envision the technology to be particularly useful for tumor targeting, as the same optical fiber that can deliver laser radiation can also be used to sense the temperature of the tumor and surrounding tissues. This can improve the safety of tumor treatments while achieving greater accuracy at removing unwanted tissue.
Here’s a bit of detail from the study abstract in Optics Letters:
Bragg gratings, with average refractive index changes of 5.8×10−45.8×10−4, were inscribed using 193 nm excimer laser radiation. Results on the dissolution of the irradiated fiber in simulated physiological conditions are presented after immersing a tilted Bragg grating in a phosphate buffered saline solution for 56 h; selective chemical etching effects are also reported. The investigations performed pave the way toward the use of such phosphate glass fiber Bragg gratings for the development of soluble photonic sensing probes for the efficient in vivo monitoring of vital mechanical or chemical parameters.
Study in Optics Letters: Bioresorbable optical fiber Bragg gratings…
Via: The Optical Society…