Actuating an optical fiber with a piezoelectric actuator and detecting voltages generated by the piezoelectric actuator

• US 20090026888A1
• Filed: 07/25/2007
• Published: 01/29/2009
• Est. Priority Date: 07/25/2007
• Status: Active Grant

• Current Assignee: Washington University In St Louis
• Original Assignee: University of Washington
• Inventors: Melville, Charles David
• Granted Patent: US 8,437,587 B2
• Time in Patent Office: Days
• US Class Current: 310/335
• CPC Class Codes: A61B 1/00096 Optical elements
• CPC Class Codes: A61B 1/00172 with means for scanning
• CPC Class Codes: A61B 2018/2238 with means for selectively laterally deflecting the tip of the fibre
• CPC Class Codes: A61B 5/0062 Arrangements for scanning
• CPC Class Codes: G02B 26/103 having movable or deformable optical fibres, light guides or waveguides as scanning elements light guides per se G02B6/00
• CPC Class Codes: H10N 30/2046 adapted for multi-directional bending displacement
• CPC Class Codes: H10N 30/802 Circuitry or processes for operating piezoelectric or electrostrictive devices not otherwise provided for, e.g. drive circuits

Abstract

A method of one aspect may include actuating a cantilevered optical fiber by mechanically deforming a piezoelectric actuator. An electrical signal generated as a result of mechanical deformation of the piezoelectric actuator may also be detected.

Claims

1. A method comprising:

actuating a cantilevered optical fiber by mechanically deforming a piezoelectric actuator; and

detecting an electrical signal generated as a result of mechanical deformation of the piezoelectric actuator.

2. The method of claim 1, further comprising estimating a position of at least one of the piezoelectric actuator and the cantilevered optical fiber based on the detected electrical signal.

3. The method of claim 1, further comprising actuating the cantilevered optical fiber based at least in part on the detected electrical signal.

4. The method of claim 3, wherein actuating the cantilevered optical fiber based at least in part on the detected electrical signal comprises:

determining an actuator drive signal based at least in part on the detected electrical signal; and

applying the determined actuator drive signal to the piezoelectric actuator.

5. The method of claim 1, wherein actuating the cantilevered optical fiber comprises applying actuator drive signals to the piezoelectric actuator, and further comprising decoupling the actuator drive signals from the piezoelectric actuator while the electrical signal is detected.

6. The method of claim 1, wherein detecting the electrical signal comprises detecting the electrical signal during active braking.

7. The method of claim 6, further comprising performing additional active braking by actuating the cantilevered optical fiber based at least in part on the detected electrical signal.

8. The method of claim 6, further comprising determining to stop active braking based at least in part on the detected electrical signal.

9. The method of claim 1, wherein detecting the electrical signal comprises detecting the electrical signal at one of during a period of active driving and at an end of a period of active driving.

10. The method of claim 9, further comprising:

determining an actuator drive signal based at least in part on the detected electrical signal; and

applying the determined actuator drive signal to the piezoelectric actuator.

11. The method of claim 1, wherein actuating the cantilevered optical fiber with the piezoelectric actuator comprises actuating the cantilevered optical fiber with a piezoelectric tube through which the cantilevered optical fiber is inserted.

12. The method of claim 11, wherein detecting the electrical signal comprises detecting the electrical signal on a first side of the piezoelectric tube, and further comprising detecting a electrical signal on a second side of the piezoelectric tube that is orthogonal to the first side.

13. The method of claim 1, further comprising inserting the cantilevered optical fiber into a patient.

14. The method of claim 1, wherein actuating the cantilevered optical fiber comprises vibrating the cantilevered optical fiber within a Q-factor of a resonant frequency.

15. An apparatus comprising:

a connector interface to allow a scanning fiber device to be connected;

a light source optically coupled with the connector interface to provide light to the scanning fiber device through the connector interface;

an actuator driver to provide actuator drive signals to a piezoelectric actuator of the scanning fiber device through the connector interface; and

a voltage detector to detect a voltage generated due to mechanical deformation of the piezoelectric actuator that is returned through the connector interface.

16. The apparatus of claim 15, wherein the actuator driver is switchably electrically coupled with the connector interface.

17. The apparatus of claim 16, wherein the voltage detector is switchably electrically coupled with the connector interface.

18. The apparatus of claim 16, further comprising a switch electrically coupled with the actuator driver and with the connector interface and operable to switchably electrically couple or not couple the actuator driver with the connector interface.

19. The apparatus of claim 18, wherein the voltage detector is electrically coupled with the switch, and wherein the switch is operable to switchably electrically couple or not couple the voltage detector with the connector interface.

20. The apparatus of claim 15, further comprising a high impedance line having an impedance of at least one mega ohm between the voltage detector and the connector interface.

21. The apparatus of claim 20, wherein the high impedance line comprises a high impedance amplifier.

22. The apparatus of claim 15, wherein the voltage detector is electrically coupled with a plurality of conductive paths, and wherein the plurality of conductive paths are at least switchably electrically coupled with a corresponding plurality of electrodes on orthogonal sides of the piezoelectric actuator.

23. The apparatus of claim 15, further comprising a position estimation unit to estimate a position of one or more of the piezoelectric actuator and a cantilevered optical fiber coupled with the piezoelectric actuator based at least in part on the detected voltage.

24. The apparatus of claim 15, further comprising an actuator drive signal determination unit to determine an actuator drive signal based at least in part on the detected voltage.