Miniaturized triaxial optical fiber force sensor for MRI-Guided minimally invasive surgery

Abstract

Abstract-This paper describes the design and construction of a miniaturized triaxial force sensor which can be applied inside a magnetic resonance imaging (MRI) machine. The sensing principle of the sensor is based on an optical intensity modulation mechanism that utilizes bent-tip optical fibers to measure the deflection of a compliant platform when exposed to a force. By measuring the deflection of the platform using this optical approach, the magnitude and direction of three orthogonal force components (F x , F y , and F z ) can be determined. The sensor prototype described in this paper demonstrates that it can perform force measurements in axial and radial directions with working ranges of +/-2 N. Since the sensor is small in size and entirely made of nonmetallic materials, it is compatible with minimally invasive surgery (MIS) and safe to be deployed within magnetic resonance (MR) environments.

Fiber-optic-based force and shape sensing in surgical robots: a review

“…Different from the sensor in Lazeroms et al (1996), Bandari et al (2020) and De Chiara et al (2020), the metallic flexible structures are helpful to guarantee higher stiffness of MIS gripper and better linearity in measuring range of sensor. Meanwhile, deformations caused by axial and radial forces can be decoupled using parallelogram structures with stiffness difference of adjacent beams (Puangmali et al , 2008b; Puangmali et al , 2010; Puangmali et al , 2012). Compared with vertical beams, the stiffness of horizontal beams is much lower.…”

“…Above measures keep the balance between stiffness and sensitivity of tool. Puangmali et al (2010Puangmali et al ( , 2012 have also designed a 3-DOF force sensing palpation tool [Figure 4(a)]. Reference fibers for bending compensation are also connected.…”

A highly sensitive force sensor based on two identical fiber Bragg gratings

“…There are great demands for micro-force measurements in the fields of nanoparticle interactions, cell mechanics and engineering applications [1][2][3][4][5][6]. At present, a variety of optical fiber-based force sensors have been fabricated, with sensing mechanisms including F-P interferometers [6][7][8], power modulation of multi-hole plastic optical fibers and miniaturized triaxial optical fibers [9,10], polarization modulation of singlemode polarization-maintaining fibers and microfiber couplers [11,12]. Fiber Bragg grating (FBG) sensors are extensively studied based on wavelength modulation, with advantages a of sharp reflection peak and sensitive wavelength shift [13][14][15].…”