SCANNING BEAM WITH VARIABLE SEQUENTIAL FRAMING USING INTERRUPTED SCANNING RESONANCE

• US 20090028407A1
• Filed: 11/23/2005
• Published: 01/29/2009
• Est. Priority Date: 11/23/2005
• Status: Active Grant

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Tuttle, Brandon, Seibel, Eric, Johnston, Richard
• Granted Patent: US 8,537,203 B2
• Time in Patent Office: Days
• US Class Current: 382/131
• CPC Class Codes: A61B 1/0008 characterised by distal tip features
• CPC Class Codes: A61B 1/00172 with means for scanning
• CPC Class Codes: A61B 1/0607 for annular illumination
• CPC Class Codes: A61B 1/0627 for variable illumination angles
• CPC Class Codes: A61B 2018/20351 Scanning mechanisms
• CPC Class Codes: A61B 2018/20357 by movable optical fibre end
• CPC Class Codes: A61B 2018/20361 with redirecting based on sensed condition, e.g. tissue analysis or tissue movement
• CPC Class Codes: A61N 5/0601 Apparatus for use inside the body
• CPC Class Codes: A61N 5/062 Photodynamic therapy, i.e. excitation of an agent
• CPC Class Codes: G01N 21/64 Fluorescence; Phosphorescence
• CPC Class Codes: G02B 23/2423 of the distal end
• 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

Abstract

A scanning device for use in an endoscope or other applications can be driven to scan a region with one or more different scanning parameters during successive scanning frames. The scanning device, which can include an optical fiber or reflective surface driven by an actuator to move relative to one or more axes, can be provided with a drive signal that is different during successive scanning frames so that the scanning pattern can be caused to differ between the successive scanning frames by one or more of size, amplitude in at least one direction, depth, duration, shape, and resolution. Thus, different scanning frames can be employed for imaging, carrying out a diagnosis, rendering a therapy, and/or monitoring a site, using the appropriate scanning pattern, appropriate light source, and other parameters for each function that is carried out by the scanning device.

Claims

1. A scanning device that is employed to scan a region with a beam of light during a plurality of scanning frames, comprising:

(a) a light conductive medium configured to convey light from a source, for scanning the region with the light, wherein the light conductive medium comprises an optical fiber;

(b) a scanning element coupled to the light conductive medium and configured to direct light conveyed through the light conductive medium to the region by scanning the region in a desired pattern;

(c) a driver that is coupled to the scanning element, the driver applying a force to the scanning element causing the scanning element to move so that the light beam scans over the region in the desired pattern; and

(d) a control that supplies a driving signal to the driver to vary at least one of an amplitude and a direction of the force applied by the driver to the scanning element, the driving signal causing the driver to move the scanning element in a first mode during one scanning frame in order to achieve a function, and to move the same scanning element in a second mode during a subsequent scanning frame in order to achieve a different function, wherein at least one characteristic of the desired pattern in the first mode is substantially different in the second mode.

2. The scanning device of claim 1, wherein the driver applies the force to move the scanning element relative to two generally orthogonal directions.

3. The scanning device of claim 1, wherein the scanning element comprises a movably mounted light reflective surface that is driven by the driver to move, reflecting the light beam toward the region so that the light beam scans the region in the desired pattern.

4. The scanning device of claim 1, wherein the force applied by the driver drives the scanning element generally into a resonant motion, to achieve the desired pattern, the resonant motion of the scanning element being interrupted between the one scanning frame and the subsequent scanning frame.

5. The scanning device of claim 1, wherein the light conductive medium is configured to be coupled to a first source of light during the one scanning frame and to a second source of light during the subsequent scanning frame, the first source producing light that is substantially different than the light produced by the second source.

6. The scanning device of claim 4, wherein the light produced by the first source substantially differs from the light produced by the second source in regard to at least one of:

(a) an intensity of the light;

(b) a waveband of the light; and

(c) a modulation frequency of the light.

7. The scanning device of claim 1, wherein the at least one characteristic of the desired pattern that is different in the first mode than in the second mode is at least one of:

(a) a scan pattern size;

(b) a scan pattern shape;

(c) a scan pattern duration;

(d) a resolution of the scan pattern; and

(e) a quality of the light comprising the light beam.

8. The scanning device of claim 1, wherein the control selectively controls a dwell time for scanning the light beam over the region, so that a substantially different dwell time is employed during the first mode than during the second mode.

9. The scanning device of claim 1, further comprising a light detector that receives light from the region, the light detector being configured to connect to a display for displaying an image of the region.

10. The scanning device of claim 8, wherein the first mode is used for at least one function selected from the group of functions consisting of:

(a) imaging the region;

(b) monitoring a state of the region;

(c) providing a therapy with the light beam to the region; and

(d) diagnosing a condition of the region.

11. The scanning device of claim 8, wherein the second mode is used for at least one of the functions of:

(a) imaging the region;

(b) monitoring a state of the region;

(c) providing a therapy with the light beam to the region; and

(d) diagnosing a condition of the region.

12. The scanning device of claim 1, wherein the desired pattern in each of the first mode and the second mode comprises at least one of:

(a) a generally circular scan;

(b) a generally elliptical scan;

(c) a point scan in which the scanning device is substantially illuminating a point;

(d) a linear scan;

(e) a propeller scan; and

(e) a Lissajous scan.

13. The scanning device of claim 1, wherein ends of the light conductive medium have been conditioned to allow the propagation of higher intensities of light without damage, the conditioning utilizing at least one of:

(a) an end cap;

(b) an aperture;

(c) a mechanical polish;

(d) an optical polish; and

(e) a hermetic seal.

14. The scanning device of claim 1, further comprising means for monitoring an entry face of the light conductive medium for damage using at least one of:

(a) video imaging; and

(b) reflectance monitoring.

15. The scanning device of claim 1, further comprising a motion control system for controlling a position of an entry face of the light conductive medium, enabling an alignment of the light conductive medium to be executed by a user.

16. The scanning device of claim 1, wherein a progress of therapy applied with the scanning device is monitored by collecting feedback from a region of interest as at least one of:

(a) infrared radiation;

(b) an optical polarization; and

(c) a time of flight measurement.

17. A method for scanning a light beam over a region to achieve a plurality of different functions during subsequent scanning frames, comprising the steps of:

(a) driving a scanning element in a first scanning pattern, to scan the region with a light beam during one scanning frame;

(b) driving the same scanning element in a second scanning pattern, to scan the region with the light beam during a subsequent scanning frame, the first scanning pattern differing substantially in at least one characteristic from the second scanning pattern;

(c) providing light for the light beam that is appropriate to carry out a first function when scanning the light beam in the region using the first scanning pattern; and

(d) providing light for the light beam that is appropriate to carry out a second function when scanning the light beam in the region using the second scanning pattern, wherein the second function is different from the first function.

18. The method of claim 17, wherein the scanning element comprises a light reflective surface that is pivotally mounted to scan the region with the light beam when the light reflective mirror is driven in at least one of the first scanning pattern, and the second scanning pattern.

19. The method of claim 17, further comprising the step of imaging light from the region produced by scanning the region in one of the first scanning pattern and the second scanning pattern.

20. The method of claim 17, wherein the first function comprises at least one of:

(a) imaging the region;

(b) providing a therapy to the region with the light beam;

(c) diagnosing a condition of the region; and

(d) monitoring the region.

21. The method of claim 17, wherein the second function comprises at least one of:

(a) imaging the region;

(b) providing a therapy to the region with the light beam;

(c) diagnosing a condition of the region; and

(d) monitoring the region.

22. The method of claim 17, wherein at least one of the steps of driving the scanning element in the first pattern and of driving the scanning element in the second pattern comprises the step of causing the scanning element to move in a substantially resonant condition.

23. The method of claim 17, wherein the at least one characteristic by which the first pattern differs from the second pattern comprises at least one of:

(a) a size;

(b) an amplitude in at least one direction;

(c) a duration;

(d) a shape;

(e) a resolution; and

(f) a depth.

24. The method of claim 17, further comprising the step of providing a selectively variable dwell time, so that a substantially different dwell time is used for the first scanning mode than for the second scanning mode.

25. The method of claim 17, wherein the steps of driving the light conductive medium in the first scanning mode and the second mode each comprises the step of driving the light conductive medium in at least one of:

(a) a generally circular scan;

(b) a generally elliptical scan;

(c) a point scan in which the scanning device is not moving relative to a point in the region;

(d) a linear scan;

(e) a propeller scan; and

(f) a Lissajous scan.

26. The method of claim 17, further comprising the step of:

(a) receiving light from the region; and

(b) in response to the light received, producing an image of the region.

27. The method of claim 26, wherein the light received from the region is provided by the light beam scanning the region during at least one of the first scanning mode and the second scanning mode.

28. The method of claim 26, further comprising the step of scanning a smaller portion of the region during one of the first scanning mode and the second scanning mode than during the other of the first scanning mode and the second scanning mode, to zoom in on the smaller portion as viewed in the image.

29. The method of claim 17, further comprising the step of employing a substantially higher intensity light source for the light beam during at least one of the first scanning mode and the second scanning mode, the substantially higher intensity light source being used to provide a therapy to the region.

30. The method of claim 17, wherein the steps of driving the light conductive medium to scan in at least one of the first scanning mode and the second scanning mode, comprises the step of providing an amplitude modulated drive signal to drive the scanning element, the amplitude modulated drive signal being interrupted between scanning modes.

31. The method of claim 17, wherein at least one of the steps of driving the scanning element to scan comprises the step of directing the scanning element to selectively scan one or more different substantially smaller portions of the region, by controlling a direction and an amplitude of the scanning of the light beam to direct the light beam at each smaller region.

32. The method of claim 17, further comprising the step of interrupting scanning of the region with the light beam at a desired position, to render a diagnostic function, comprising at least one of:

(a) detecting a fluorescence at the desired position;

(b) determine one of a fluorescence and phosphorescence lifetime at the desired position;

(c) conducting a laser-induced fluorescence spectroscopic analysis at the desired position;

(d) conducting a white light reflectance spectroscopic analysis at the desired position;

(e) conducting a Raman spectroscopic analysis at the desired position;

(f) conducting a range finding to determine a range to the desired position;

(g) conducting an optical coherence reflectance depth measurement at the desired position; and

(h) conducting a multi-photon investigation at the desired position.

33. The method of claim 17, further comprising the step of interrupting scanning of the region with the light beam at a desired position, to render a therapeutic function, and carrying out at least one of:

(a) performing an ablation at the desired position;

(b) causing heating at the desired position;

(c) carrying out photodynamic therapy at the desired position;

(d) causing photo-ionization at the desired position;

(e) causing photo-polymerization at the desired position;

(f) causing photo-acoustic vibration at the desired position; and

(g) causing photo-activating of molecules at the desired position.

34. The method of claim 17, wherein at least one of the first scanning mode and the second scanning mode is employed for one of

(a) a laser illumination optoporation procedure;

and

(b) a vision modification procedure.

35. The method of claim 17, further comprising the step of driving the scanning element in one or more additional scanning modes to provide additional functions in regard to the region being scanned with a light beam, at least one characteristic of the each additional scanning mode differing from a corresponding characteristic in each other scanning mode.

36. The method of claim 17, further comprising the step of employing an extrinsic chromaphore to aid light absorption.

37. The method of claim 17, further comprising the step of employing an extrinsic fluorophore to aid optical diagnosis.