There is a need for precision pathological sensing, imaging, and tissue manipulation in neurosurgical procedures, such as brain tumor resection. Precise tumor margin identification and resection can prevent further growth and protect critical structures. Surgical lasers with small laser diameters and steering capabilities can allow for new minimally invasive procedures by traversing through complex anatomy, then providing energy to sense, visualize, and affect tissue. In this paper, we present the design of a small-scale tendon-actuated galvanometer (TAG) that can serve as an end-effector tool for a steerable surgical laser. The galvanometer sensor design, fabrication, and kinematic modeling are presented and derived. It can accurately rotate up to 30.14 degrees (or a laser reflection angle of 60.28 degrees). A kinematic mapping of input tendon stroke to output galvanometer angle change and a forward-kinematics model relating the end of the continuum joint to the laser end-point are derived and validated.

Existing galvanometer-based laser scanning systems are challenging to apply in multi-scale 3D reconstruction because of the difficulty in achieving a balance between high reconstruction accuracy and a wide reconstruction range. This paper presents a novel method that synchronizes laser scanning by switching the field-of-view (FOV) of a camera using multi-galvanometers. In addition to the advanced hardware setup, we establish a comprehensive mathematical model of the system by modeling dynamic camera, dynamic laser, and their combined interaction. We then propose a high-precision and flexible calibration method by constructing an error model and minimizing the objective function. Finally, we evaluate the performance of the proposed system by scanning standard components. The evaluation results demonstrate that the accuracy of the proposed 3D reconstruction system achieves 0.3 mm when the measurement range is extended to 1100 mm $\times$ 1300 mm $\times$ 650 mm. With the same reconstruction accuracy, the reconstruction range is expanded by a factor of 25, indicating that the proposed method simultaneously allows for high-precision and wide-range 3D reconstruction in industrial applications.