Vitreoretinal surgery is a technically demanding ophthalmologic discipline. One of the main technical challenges in
vitreoretinal surgery is the lack of force sensing since the surgical maneuvers fall below the human sensory threshold.
Previously, a 2-degree-of-freedom (DOF) force sensing instrument with a surgical pick was developed and tested.
However, a more commonly used instrument for vitreoretinal surgery is the forceps, with which a surgeon can easily
grasp and delaminate the scar tissue.
We have designed, fabricated and calibrated a novel 20-gauge (Ga) microsurgical instrument with a 2-DOF force
sensing forceps. Three fiber Bragg grating (FBG) sensors are integrated into the customized Alcon<sup>TM</sup> forceps tip. The
redundant sensor configuration provides good compensation for temperature-related drift. The calibration data show that
the tool can provide a force resolution of 0.25 mN.
In order to test the functionality and performance, the forceps was evaluated in inner shell membrane peeling
experiments with chicken embryos as well as in in-vivo rabbit experiments. The instrument has demonstrated the
capability of being applied in the clinical environment, with consistent force measurements. The force exerted in inner
shell membrane peeling is from 6.07 to 34.65 mN. The development of the 2-DOF force sensing micro-forceps has
shown that the fabrication process is feasible and reliable, and it can be used to develop a future 3-DOF force sensing
We present a new automatic spectral calibration (ASC) method for spectral Domain
optical coherence tomography (SD-OCT). Our ASC method calibrates the spectral
mapping of the spectrometer in SD-OCT, and does not require external calibrating light
source or a commercial spectral analyzer. The ASC method simultaneously calibrates the
physical pixel spacing of the A-scan in static and dynamic environments. Experimental
results show that the proposed ASC method can provide satisfactory calibration for
SD-OCT to achieve high axial resolution and high ranging accuracy, without increasing