MR Compatible Puncture Needle for Brain Stereotactic Surgery With FBG Force Sensing

In brain stereotactic surgery, a puncture needle needs to be accurately targeted toward the lesion site in the brain. During puncture, force feedback from the needle tip can effectively prevent brain tissue injury. Magnetic resonance (MR) imaging is a promising technology in brain stereotactic surgery due to its superior contrast and resolution in soft tissues. Therefore, an MR compatible puncture needle is proposed for brain stereotactic surgery in this article, where the interaction force between the brain tissue and the needle tip is measured via fiber Bragg grating (FBG) sensor. The needle is composed of a needle and a cannula, and an FBG force sensor is integrated on the needle tip. A decoupling model of the 3-degrees-of-freedom (DOF) force is proposed via the mixed calibration method of least square and radial basis function (RBF) neural network. In addition, temperature compensation is realized, and the influence of nonlinear interference on axial force is eliminated. The experimental results show that the calculation accuracy of the proposed decoupling algorithm for 3-DOF forces is less than 1.6% of the full range. The puncture needle can provide accurate 3-DOF force feedback in the temperature range of 25 °C–40 °C.