Fibre Bragg grating sensors for sutural expansion assessment in rapid palatal expanders: an ex-vivo validation

• Published in: IET optoelectronics Vol. 14; no. 6; pp. 337 - 342
• Main Authors: Coimbra, Wagner, Campos, Vinicius, Oliveira, Pedro Lima Emmerich, Frizera, Anselmo, Sant'Anna, Eduardo F, Souza Araújo, Mônica T, Andrade, Rafhael, Leal-Junior, Arnaldo
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01.12.2020
• Subjects: anterior region; biomechanics; biomedical equipment; bone; bone‐borne expander; Bragg gratings; correction coefficient; dentistry; ex‐vivo experiments; ex‐vivo validation; fibre Bragg grating‐based sensor system; fibre optic sensors; finite element analysis; Hyrax; intrinsic safe operation; microimplant‐assisted rapid palatal expansion; midpalatal suture; multiplexing capability; normal stress; porcine head; porcine palatal region; rapid palatal expanders; RPEs; sensor characterisation tests; sensor positioning; shear stress; Special Section: 2019 International Microwave and Optoelectronics Conference; strain measurement; strain transfer model; sutural expansion assessment; tooth‐borne expander; anterior region; multiplexing capability; finite-element analysis; dentistry; ex-vivo validation; biomedical equipment; sensor characterisation tests; porcine palatal region; biomechanics; intrinsic safe operation; shear stress; strain measurement; fibre optic sensors; fibre Bragg grating-based sensor system; tooth-borne expander; midpalatal suture; sensor positioning; bone; rapid palatal expanders; RPEs; finite element analysis; strain transfer model; Bragg gratings; porcine head; bone-borne expander; normal stress; Hyrax; sutural expansion assessment; correction coefficient; ex-vivo experiments; microimplant-assisted rapid palatal expansion
• ISSN: 1751-8768; 1751-8776
• DOI: 10.1049/iet-opt.2020.0044

This study presents the development and validation of a fibre Bragg gratings (FBGs)-based sensor system for the assessment of strain in the midpalatal suture in subjects using rapid palatal expanders (RPEs). The ex-vivo experiments were made by means of positioning two RPEs in a porcine palatal region. The RPEs used were the Hyrax, a tooth-borne expander and MARPE (microimplant-assisted rapid palatal expansion), a bone-borne expander. In order to define the regions in the palatal region for the sensors positioning, a finite-element analysis was performed in a porcine head subjected to the loadings caused by an RPE. In addition, a strain transfer model was used to obtain a correction coefficient that approximates the strain estimated by the FBG to the actual strain in the structure under shear and normal stress. Results show high linearity in the sensors characterisation tests with the advantages of compactness, intrinsic safe operation and multiplexing capabilities of FBGs. In the RPE analysis, a higher strain was estimated in the anterior region, which is in accordance with the simulation and previously reported results, where MARPE showed a higher strain (with an exponential pattern) than Hyrax as the number of activations increase.