Fig. 1. Schematic of IVOCT probe based on miniature propeller

Fig. 2. Force analysis of single blade with different inclination angles. (a) A blade with a small inclination angle; (b) a blade with a large inclination angle

Fig. 3. Inclination angle analysis of miniature propeller blade

Fig. 4. Resistance analysis of miniature propeller

Fig. 5. Variation of resistance moment with time at different contact angles

Fig. 6. Photo of the miniature propeller

Fig. 7. Photo of probe with outer diameter of 1.5 mm

Fig. 8. Schematic of experimental system (dotted line represents the electric signal,solid line represents the optical signal)

Fig. 9. Flow chart of data processing algorithm

Fig. 10. Tomogram of a marked white tape sample

Fig. 11. Variation of rotation speed of probe with time under different gears

Fig. 12. OCT images obtained with proposed probe. (a) White tape; (b) spring onion tube; (c) in vitro chicken heart artery vessel