System and method for fluorescence-based laser ablation

• US 10,052,154 B2
• Filed: 10/01/2014
• Issued: 08/21/2018
• Est. Priority Date: 10/01/2014
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Verily Life Sciences LLC (Alphabet Inc.)
• Inventors: Rephaeli, Eden, Wang, Chia-Jean
• Primary Examiner(s): Jackson, Gary
• Assistant Examiner(s): Kabir, Zahed
• Application Number:
  US14/503,706
• Publication Number:
  US 20160095661A1
• Time in Patent Office: 1,420 Days
• Field of Search: 606 3
• CPC Class Codes: A61B 1/043 for fluorescence imaging
• CPC Class Codes: A61B 18/203 applying laser energy to the outside of the body
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00779 Power or energy
• CPC Class Codes: A61B 2018/00904 Automatic detection of target tissue
• CPC Class Codes: A61B 2018/20359 by movable mirrors, e.g. galvanometric
• CPC Class Codes: A61B 2018/20361 with redirecting based on sensed condition, e.g. tissue analysis or tissue movement
• CPC Class Codes: A61B 2018/2266 with a lens, e.g. ball tipped
• CPC Class Codes: A61B 2090/3612 with images taken automatically
• CPC Class Codes: A61B 2090/373 using light, e.g. by using optical scanners
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61B 2090/376 using X-rays, e.g. fluoroscopy
• CPC Class Codes: A61B 5/0036 including treatment, e.g., using an implantable medical device, ablating, ventilating
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 90/30 Devices for illuminating a surgical field, the devices having an interrelation with other surgical devices or with a surgical procedure
• CPC Class Codes: A61B 90/36 Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: A61B 90/361 Image-producing devices, e.g. surgical cameras
• CPC Class Codes: A61B 90/37 Surgical systems with images on a monitor during operation
• CPC Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence
• CPC Class Codes: G02B 27/141 : using dichroic mirrors

Abstract

In an embodiment, an apparatus and method are described for ablating tissue in response to determining a fluorescence condition. An excitation light source may produce excitation light at a excitation wavelength of a fluorophore. A beam scanner may direct the excitation light towards a tissue location. A fluorophore may produce emission light in response to absorbing the excitation light. A camera may capture an image of the tissue location. In response to the image indicating emission light at the tissue location, an ablation light source may produce ablation light. The beam scanner may direct the ablation light towards the tissue location. Additionally or alternatively, a topography map may be generated and certain aspects of the apparatus and/or the method may be adjusted based on the topography map.

Claims

1. An apparatus comprising:

an excitation light source configured to produce excitation light wherein the excitation light comprises light having a wavelength that corresponds to an excitation wavelength of a fluorophore, wherein the fluorophore is configured to emit emission light at an emission wavelength in response to receiving light at the excitation wavelength;

an ablation light source configured to produce ablation light wherein the ablation light is configured to ablate tissue;

a beam combiner optically coupled to the excitation light source and the ablation light source;

a camera configured to detect the emission light emitted by the fluorophore; and

a controller, wherein the controller comprises a computer programmed to carry out instructions, the instructions comprising;

causing the excitation light source to produce excitation light;

causing the camera to capture an image of at least a particular tissue location;

determining a topographical map of at least the particular tissue location based on a location of the camera and an angle of the excitation light with respect to the particular tissue location from the plurality of tissue locations;

determining a fluorescence condition based on the image indicating emission light at the emission wavelength at the particular tissue location; and

responsive to the fluorescence condition, causing the ablation light source to produce ablation light.

2. The apparatus of claim 1 further comprising:

a beam scanner optically coupled to the beam combiner and operable to direct the excitation light and the ablation light toward any of a plurality of tissue locations, wherein the plurality of tissue locations comprise the particular tissue location;

wherein the instructions further comprise;

causing the beam scanner to direct the excitation light towards the particular tissue location.

3. The apparatus of claim 2 further comprising an optical system optically coupled to the beam scanner, wherein the optical system comprises an exit aperture and a lens, and wherein the controller is further configured to determine a focal distance to the particular tissue location based on the topographical map, wherein the ablation light source is operated to produce the ablation light and the beam scanner is operated to direct the ablation light towards the particular tissue location based on the determined focal distance such that the ablation light is provided in-focus to the particular tissue location.

4. The apparatus of claim 3 wherein the lens comprises zinc selenide (ZnSe).

5. The apparatus of claim 3 wherein the optical system is configured to correct field curvature.

6. The apparatus of claim 2, wherein the beam scanner comprises a dual galvanometer scanning mirror operable to deflect the excitation light and the ablation light within a deflection range that encompasses the plurality of tissue locations.

7. The apparatus of claim 2 wherein the controller is further configured to:

while the ablation light source is producing ablation light, cause the camera to capture a second image of at least the particular tissue location and control the ablation light source based on the second image.

8. The apparatus of claim 2 further comprising a beam delivery system optically coupled to the beam combiner and the beam scanner and wherein the beam delivery system comprises an optical fiber.

9. The apparatus of claim 1 wherein the beam combiner comprises a fiber optic y-coupler.

10. The apparatus of claim 1 wherein the excitation light source comprises a laser, and wherein the excitation wavelength is between 380 nm and 1.4 microns.

11. The apparatus of claim 1 wherein the ablation light source comprises a carbon dioxide (CO₂) laser configured to produce the ablation light at an ablation wavelength between 1.4 microns and 12 microns.

12. The apparatus of claim 1 wherein the beam combiner comprises a dichroic material.

13. A method comprising

causing an excitation light source to produce excitation light wherein the excitation light comprises light having a wavelength that corresponds to an excitation wavelength of a fluorophore, wherein the fluorophore is configured to emit emission light at an emission wavelength in response to receiving light at the excitation wavelength;

causing a beam scanner to direct the excitation light towards a particular tissue location, wherein the beam scanner is operable to direct the excitation light toward any of a plurality of tissue locations;

causing a camera to capture an image of at least the particular tissue location wherein the camera is configured to detect the emission light emitted by the fluorophore;

determining a topographical map of at least the particular tissue location based on a location of the camera and an angle of the excitation light with respect to the particular tissue location from the plurality of tissue locations;

determining a fluorescence condition based on the image indicating emission light at the emission wavelength at the particular tissue location; and

responsive to the fluorescence condition, causing an ablation light source to produce ablation light and causing the beam scanner to direct the ablation light towards the particular tissue location, wherein the ablation light source and the excitation light source are optically coupled to a beam combiner and wherein the beam combiner is optically coupled to the beam scanner.

14. The method of claim 13 wherein the beam scanner comprises an optical system, and wherein the optical system comprises an exit aperture and a lens.

15. The method of claim 13 further comprising determining a focal distance to the particular tissue location based on the topographical map, wherein the ablation light source is operated to produce the ablation light and the beam scanner is operated to direct the ablation light towards the particular tissue location based on the determined focal distance such that the ablation light is provided in-focus to the particular tissue location.

16. The method of claim 13 wherein the beam scanner comprises a dual galvanometer scanning mirror operable to deflect the excitation light and the ablation light within a deflection range that encompasses the plurality of tissue locations.

17. The method of claim 13 further comprising while the ablation light source is producing ablation light, causing the camera to capture a second image of at least the particular tissue location and controlling the ablation light source based on the second image.

18. The method of claim 13 wherein the excitation light further comprises light having a second wavelength that corresponds to a second excitation wavelength of a second fluorophore, wherein the fluorophore is configured to emit second emission light at a second emission wavelength in response to receiving light at the second excitation wavelength, and determining the fluorescence condition based further on the image indicating second emission light at the second emission wavelength at the particular tissue location being below a threshold.

19. A method comprising:

determining a topographical map based on a location of a camera, a location of an exit aperture of a beam scanner, and an angle of excitation light with respect to a particular tissue location of a plurality of tissue locations;

determining a focal distance to the particular tissue location based on the topographical map;

causing an excitation light source to produce excitation light wherein the excitation light comprises light having a wavelength that corresponds to an excitation wavelength of a fluorophore, wherein the fluorophore is configured to emit emission light at an emission wavelength in response to receiving light at the excitation wavelength;

causing a beam scanner to direct the excitation light towards a particular tissue location, wherein the beam scanner is operable to direct the excitation light toward any of a plurality of tissue locations;

causing a camera to capture an image of at least the particular tissue location wherein the camera is configured to detect the emission light emitted by the fluorophore;

determining a fluorescence condition based on the image indicating emission light at the emission wavelength at the particular tissue location; and

responsive to the fluorescence condition, causing an ablation light source to produce ablation light and causing the beam scanner to direct the ablation light towards the particular tissue location based at least on the focal distance to the particular tissue location, and wherein the ablation light source and the excitation light source are optically coupled to a beam combiner, and wherein the beam combiner is optically coupled to the beam scanner.

20. The method of claim 19 further comprising while the ablation light source is producing ablation light, causing the camera to capture a second image of at least the particular tissue location and controlling the ablation light source based on the second image.