A scanning apparatus, the apparatus comprising: an optical fiber (202, 502); a piezoelectric actuator (204, 504, 702) coupled to the optical fiber (202, 502) to deflect a distal end of the optical fiber (202, 502) in a scanning pattern, wherein the piezoelectric actuator (204, 504, 702) comprises a plurality of electrical inputs defining movement axes of the piezoelectric actuator and the optical fiber, wherein the movement axes include a first physical axis and a second physical axis; drive circuitry coupled to the piezoelectric actuator (204, 504, 702) to output drive signals (300, 302) to the piezoelectric actuator (204, 504, 702); sense circuitry electrically coupled to the piezoelectric actuator (204, 504, 702) and the drive circuitry to isolate displacement signals generated by the displacement and/ or deformation of the piezoelectric actuator after the drive circuitry drives the piezoelectric actuator (204, 504, 702) with the drive signals (300, 302), wherein the sense circuitry comprises a bridge circuit (600, 700, 808); a processor coupled to the drive circuitry and sense circuitry to drive the piezoelectric actuator (204, 504, 702) with the drive signals (300, 302); characterised in that the processor comprises instructions to determine a first and a second rotation angle (Θ1, Θ2) defining eigendirections of the piezoelectric actuator (204, 504, 702) from the isolated displacement signals of the piezoelectric actuator (204, 504, 702) driven along the movement axes and to map the first and the second physical axes with virtual axes of the optical fiber corresponding to the eigendirections; and wherein the processor further comprises additional instructions to control displacement of the distal end of the optical fiber (202, 502) with control parameters, including the first and the second rotation angle (Θ1, Θ2), between image cycles. an optical fiber (202, 502); a piezoelectric actuator (204, 504, 702) coupled to the optical fiber (202, 502) to deflect a distal end of the optical fiber (202, 502) in a scanning pattern, wherein the piezoelectric actuator (204, 504, 702) comprises a plurality of electrical inputs defining movement axes of the piezoelectric actuator and the optical fiber, wherein the movement axes include a first physical axis and a second physical axis; drive circuitry coupled to the piezoelectric actuator (204, 504, 702) to output drive signals (300, 302) to the piezoelectric actuator (204, 504, 702); sense circuitry electrically coupled to the piezoelectric actuator (204, 504, 702) and the drive circuitry to isolate displacement signals generated by the displacement and/ or deformation of the piezoelectric actuator after the drive circuitry drives the piezoelectric actuator (204, 504, 702) with the drive signals (300, 302), wherein the sense circuitry comprises a bridge circuit (600, 700, 808); a processor coupled to the drive circuitry and sense circuitry to drive the piezoelectric actuator (204, 504, 702) with the drive signals (300, 302); characterised in that the processor comprises instructions to determine a first and a second rotation angle (Θ1, Θ2) defining eigendirections of the piezoelectric actuator (204, 504, 702) from the isolated displacement signals of the piezoelectric actuator (204, 504, 702) driven along the movement axes and to map the first and the second physical axes with virtual axes of the optical fiber corresponding to the eigendirections; and wherein the processor further comprises additional instructions to control displacement of the distal end of the optical fiber (202, 502) with control parameters, including the first and the second rotation angle (Θ1, Θ2), between image cycles.