Design and Implementation of A Micro-force Sensing Instrument for Ophthalmic Surgery

In the Ophthalmic microsurgery, as the contact forces between tool and tissue are too small to perceive and the excessive operating force might lead to tissue damage, an FBG-based two-dimensional micro-force sensor is developed. After the force-wavelength relationship is determined and the temperature effect to the wavelength is discussed, an algorithm is developed to cancel the temperature effect. A calibration experiment is performed on a self-developed micro-force sensor calibration platform (the measuring accuracy is 0.42 mN). The sensor is integrated to the end of an ophthalmic surgical forceps, which was used to perform continuous curvilinear capsulorhexis (CCC) on isolated pig eyeballs to obtain the force-time curves. By analyzing 19 sets of data, the average value of the maximum capsular force was 22.43 mN. The research laid the foundation for precise operation of ophthalmic surgery and micro-force control of surgical robots. © 2020 Journal of Mechanical Engineering.