Abstract
This paper proposes a novel Fiber Bragg Grating (FBG)-based hybrid force and displacement sensor with a high sensitivity to achieve accurate measurement of radial artery pulse waveforms. The proposed sensor prototype mainly consists of a force-sensitive orthogonal planar spring structure, an FBG optical fiber, and a sensor frame. The side-type orthogonal planar spring flexure has been utilized and optimized to achieve an excellent linear force-displacement relationship along the axial direction. It offers other merits in terms of equivalent functions as a parallel mechanism configuration, compactness, and convenient assembly. The employed optical fiber has been tightly stretched to form a suspended configuration vertical to the flexure’s central line. This two-point pasting configuration and the use of the transverse movement property of the suspended fiber can achieve improved sensitivity and resolution, and avoid shortcomings associated with the traditional and direct pasting for the whole FBG element. The theoretical model that corresponds to the sensing principle has been derived. The simulation based on finite element method (FEM) has been adopted to conduct design optimization to determine detailed structural parameters and achieve enhanced sensitivity, as well as performance investigation. The optimized prototype has demonstrated an excellent force resolution of 0.47mN with a small linearity error of 0.98% within the sensing range [0.9N, 2.7N] and a high displacement sensitivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.103\mu \text{m}$ </tex-math></inline-formula> with a linearity error of 4.08% within the sensing range [0.3mm, 0.7mm], and the R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> values are determined as 99.99% and 99.30%, respectively. The experiments for artery pulse waveform measurement have been performed to validate the effectiveness of the proposed sensor design.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.