Accommodative Haptics Study Based on Flexible Amplification Mechanism

A B S T R A C T

In this study, we take the effect of the anterior movement of the optic into account and propose a novel haptic based on lever-type and bridge-type flexible amplification mechanisms. Based on the consideration of the offset of the rotation center of the flexible hinge, we have deduced the formula for calculating the amplification ratio of the proposed four-stage amplifier. The geometric parameters and the material property parameters, in terms of the clinical measurement data of the human eye, are assumed to restrain the structural features and motion trajectories for the amplifier. As the ciliary muscle achieves the contraction limit, the output displacement and amplification ratio reach the highest and lowest values, separately, and gradually approach a stable range. The amplification ratio of formula calculation and FEA (Finite Element Analysis) are around 18.86 and 17.79, respectively, with the input displacement ranging from 0.115mm to 0.127mm. The error of the amplification ratio between theoretical method and FEA is less than 5%. The presented haptic acting as a four-stage displacement amplifier, enables an improved lens power of 3.80 diopters to obtain much more focus shift to achieve a better near visual performance for patients.

Keywords

Haptic, flexible amplification mechanism, amplification ratio, flexure hinges



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Article Info

Article Type
Research Article
Publication history
Received: Tue 24, Nov 2020
Accepted: Thu 10, Dec 2020
Published: Wed 23, Dec 2020
Copyright
© 2023 Wenjing Wang. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Hosting by Science Repository.
DOI: 10.31487/j.JBEM.2020.01.03

Author Info

Corresponding Author
Wenjing Wang
Institute of Artificial Intelligence, Beijing Technology and Business University, Beijing, China

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