Optical-Waveguide Based Tactile Sensing for Surgical Instruments of Minimally Invasive Surgery

Abstract

In recent years, with the rapid development of minimally invasive surgery (MIS), the lack of force sensing associated with the surgical instrument used in MIS has been increasingly a desirable technology amongst clinicians. However, it is still an open technical challenge to date since most existing tactile sensing principles are not suitable to small 3-dimensional (3D) curved surfaces often seen in surgical instruments, and as a result multi-point force detection cannot be realized. In this paper, a novel optical waveguide-based sensor was proposed to deal with the above research gap. A sensor prototype for curved surfaces resembling the surface of dissection forceps was developed and experimentally evaluated. The static parameters and dynamic response characteristics of the sensor were measured. Results show that the static hysteresis error is less than 3%, the resolution is 0.026 N, and the repeatability is less than 1.5%. Under a frequency of 12.5 Hz, the sensor could quickly measure the variation of the force signal. We demonstrated that this small and high-precision sensitive sensor design is promising to be used for creating multiple-point tactile sensing for minimally invasive surgical instruments with 3D surfaces.

Comparison of robot-assisted vitreoretinal surgery and manual surgery in different preclinical settings: a randomized trial

“…During intraocular surgery, experts operate on tiny, delicate tissues, which require delicate manipulation and steady hand movements ( 19 ). Therefore, it is considered one of the most challenging microsurgery procedures.…”

Optical-Waveguide Based 3-Axial Tactile Sensor for Minimally Invasive Surgical Instruments

“…It is noteworthy that PTFE material with a refractive index of 1.38 was utilized as both the cladding material and the base of the sensor [34]. Under initial conditions, light propagation of the waveguides follows the principle of total internal reflection (TIR) when the angle of incidence θc is larger than the critical angle [21]. The critical angle  was calculated by (1), which was 69.84 degrees in this paper…”

“…Compared with the conventional electrical force sensing, optical-based tactile sensing has unique advantages of simplified wiring, flexibility, and biocompatibility [7], [20]. Moreover, its compatibility with sterilization processes, resistance to various chemical interferences, and immunity to electromagnetic interference make it a highly promising candidate for MIS [21], [22], [23], [24]. An optical-based sensor operates on the principle of transmitting light through an input to a detector, where the characteristics of the intensity, wavelength, amplitude, and phase, can response to change accordingly [25].…”

“…In our previous research, we proposed optical-based tactile sensors that utilizing the principle of total internal reflection (TIR) of waveguides to detect the magnitude of normal force by establishing a relationship between applied force and the output light intensity [21], [31], [32]. Furthermore, in the work of [33], we further optimized the sensor structure to differentiate between normal and shear forces from different directions through the design of a cross-symmetric structure.…”

Triaxial 3D-Channeled Soft Optical Sensor for Tactile Robots

“…Although this sensor can be easily fabricated via 3D printing and UV curing, the requirement of a bulky line scan camera strongly limits its integrability. One year later, Li et al [19] presented an optical-waveguide-based triaxial tactile sensor for laparoscopic applications using the light intensity of three intersecting planar channels to measure forces from 0 N to 3 N, at the cost of expensive demodulation equipment and complex internal wiring. In addition to academic research, noteworthy commercial solutions include OptoForce and GelSight.…”