Fig. 1. Overview of intelligent optic-assisted techniques and laser ablation in image guided minimally invasive intervention

Fig. 2. Three typical types of AR^[8]. (a) Monitor-based AR; (b) projection-based AR; (c) optical see-through AR

Fig. 3. Examples of clinical studies on AR assisted minimally invasive intervention. (a) Trans-thoracic minimally invasive surgery guided by monitor-based AR^[15]; (b) in-situ projection-based AR system for mobile C-arm^[19]; (c) projection-based AR system which contains robot, projector and camera^[21]; (d) phantom study of the pedicle screw navigation using Microsoft HoloLens; (e) external ventricular drain insertion guided by HoloLens

Fig. 4. Solutions for optical system of optical see-through AR. (a) Birdbath optics; (b) freeform prism; (c) geometric optical waveguide; (d) diffractive optical waveguide solution: surface relief grating; (e) metalens; (f) metasurface reflector

Fig. 5. Principle and applications of optical tracking. (a) Principle of optical tracking system (OTS); (b) application of OTS in robot-assisted spine surgery; (c) common OTS and tracking markers; (d) application of OTS in minimally invasive intervention

Fig. 6. Principle and applications of FBG. (a) Generalized principle of FBG as sensor; (b) principle of measuring strain or temperature using FBG^[89]; (c) application of FBG-based shape sensing for flexible needles^[91]; (d), (e) multi-dimensional force sensing design of FBG sensors in minimally invasive surgical instruments^[98-99]

Fig. 7. Scalp shape sensing based on structured light

Fig. 8. Principle and applications of laser ablation. (a) Schematic diagram of cooling mechanism for optical fiber; (b) MRI-guided laser ablation for brain tumor; (c) schematic diagram of thrombus removal by laser ablation; (d) thrombus images generated by OCT^[115]