Scanning beam with variable sequential framing using interrupted scanning resonance

• US 8,537,203 B2
• Filed: 11/23/2005
• Issued: 09/17/2013
• Est. Priority Date: 11/23/2005
• Status: Active Grant

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Seibel, Eric, Johnston, Richard, Tuttle, Brandon
• Primary Examiner(s): Nguyen, Dustin
• Application Number:
  US12/088,057
• Publication Number:
  US 20090028407A1
• Time in Patent Office: 2,855 Days
• Field of Search: 600/407, 606/5, 546/285, 356/318, 385/25, 235/462.39, 235/462.42, 359/201.1
• US Class Current: 348/45
• 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, 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 one or more desired patterns;

(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 one or more desired patterns; 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 providing a first plurality of scanning frames to generate a first scanning pattern along an axis and a second plurality of scanning frames to generate a second scanning pattern along the axis, the control comprising software that, when executed, causes the control to generate the first scanning pattern along the axis with the first plurality of scanning frames and the second scanning pattern along the axis with the second plurality of scanning frames, the first plurality of scanning frames causing the driver to move the scanning element in a first mode at a resonant or near-resonant condition to provide the first scanning pattern along the axis during each of the first plurality of scanning frames in order to achieve a first function, the second plurality of scanning frames causing the driver to move the same scanning element in a second mode to provide the second scanning pattern and scan a portion of the region with the second scanning pattern along the axis during each of the second plurality of scanning frames in order to achieve a different second function, wherein the second plurality of scanning frames interrupts the first plurality of scanning frames wherein at least one characteristic of the first scanning pattern in the first mode is different from the second scanning pattern in the second mode based on the selected first and second functions.

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 during each of the first plurality of scanning frames, so as to achieve at least one of the one or more desired patterns, the resonant motion of the scanning element being interrupted within each of the first plurality of scanning frames by the second plurality of scanning frames.

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

6. The scanning device of claim 5, wherein the light produced by the first source 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;

or

(c) a modulation frequency of the light.

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

or

(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 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 1, 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 1, wherein the second mode is capable of 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;

or

(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 illuminating a point;

(d) a linear scan;

(e) a propeller scan;

or

(f) 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;

or

(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;

or

(b) reflective 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 interests comprises at least one of:

(a) infrared radiation;

(b) an optical polarization;

or

(c) a time of flight measurement.

38. The scanning device of claim 1, wherein causing the driver to move the same scanning element in the second mode during the second plurality of scanning frames in order to achieve the different second function comprises moving the scanning element to a stopped position within each of the first plurality of scanning frames to achieve non-resonant scanning with each of the second plurality of scanning frames for the different second function.

17. A method for scanning a light beam over a region, comprising the steps of:

(a) providing light to a scanning element from a first light source for the light beam, the first light source being selected to carry out a first function when scanning the light beam in the region using a first scanning pattern along an axis;

(b) driving the scanning element in the first scanning pattern along the axis at a resonant or near-resonant condition, to scan the region with the light beam emitting light from the first light source during each of a first plurality of scanning frames;

(c) providing light to the same scanning element from a second light source for the light beam, the second light source being selected to carry out a second function when scanning the light beam in the region using a second scanning pattern along the axis; and

(d) driving the same scanning element in the second scanning pattern along the axis during each of a second plurality of scanning frames, so as to scan a portion of the region with the light beam during each of the second plurality of scanning frames, wherein the second plurality of scanning frames interrupts the first plurality of scanning frames and wherein the first scanning pattern along the axis differs in at least one characteristic from the second scanning pattern along the axis based on the selected first and second functions.

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 surface is driven in at least one of the first scanning pattern, or 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;

or

(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;

or

(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 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;

or and

(f) a depth.

24. The method of claim 17, further comprising the step of providing a selectively variable dwell time, so that a 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;

or

(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 or 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 higher intensity light source for the light beam during at least one of the first scanning mode or the second scanning mode, the 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 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;

or

(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;

or

(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 chromophore to aid light absorption.

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

39. The method of claim 17, wherein driving the same scanning element in the second scanning mode for each of the second plurality of scanning frames comprises moving the scanning element to a stopped position within each of the first plurality of scanning frames to achieve non-resonant scanning with said each of the second plurality of scanning frames for the second function.