Method and apparatus for selective treatment of biological tissue

Patent metadata

Field	Value
Publication number	US-10973578-B2
Application number	US-201715853318-A
Country	US
Kind code	B2
Filing date	Dec 22, 2017
Priority date	Dec 23, 2016
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

An exemplary treatment system can be provided which can include a laser system configured to emit at least one laser beam, and an optical system configured to focus the laser beam(s) to a focal region at a selected distance from a surface of a tissue. The focal region can be configured to illuminate at least a portion of a target. The optical system can cause an irradiation energy transferred to the focal region of the laser beam(s) to (i) generate a plasma in a first region of the tissue adjacent to the target, and (ii) avoid a generation of a plasma in a second region of the tissue. The optical system has a numerical aperture that is in the range of about 0.5 to about 0.9. An exemplary method can also be provided to control such treatment system.

First claim

What is claimed is:

1. A treatment system, comprising:
a laser system including at least one q-switched laser configured to emit at least one laser beam;
an optical system including at least one lens configured to focus the at least one laser beam to a focal region at a selected distance from a surface of a tissue, the focal region being configured to illuminate at least a portion of the tissue including a pigmented region of the tissue and an unpigmented region of the tissue; and
a control arrangement configured to control the laser system and the optical system to cause an irradiation energy transferred to the focal region of the at least one laser beam at a wavelength that is selectively absorbed by the pigmented region of the tissue and to (i) generate a thermionic plasma locally at the pigmented region of the tissue, when the focal region overlaps with the pigmented region, the thermionic plasma causing damage to the pigmented region of the tissue within the focal region, and to (ii) avoid a generation of the thermionic plasma at the unpigmented region of the tissue and avoid damage at the unpigmented region of the tissue when the focal region does not overlap with the pigmented region and overlaps with the unpigmented region,
wherein the optical system has a numerical aperture that is in the range of about 0.5 to about 0.9.

2. The treatment system of claim 1 , wherein the at least one laser beam has a wavelength in the range of about 600 nm to about 1100 nm when measured in air.

3. The treatment system of claim 1 , wherein a peak intensity of the at least one laser beam is at least about 10{circumflex over ( )}8 W/cm 2 in the focal region.

4. The treatment system of claim 1 , wherein the at least one laser beam comprises (i) a first laser pulse configured to generate a thermionic emission of electrons, and (ii) a second laser pulse configured to generate the thermionic plasma.

5. The treatment system of claim 1 , wherein a spot size of the focal region is in the range of about 5 μm to about 100 μm when measured in air.

6. The treatment system of claim 1 , wherein the at least one lens of the optical system is configured to vary the selected distance of the focal region with respect to the surface of the tissue.

7. The treatment system of claim 6 , wherein the selected distance of the focal region from the surface of the tissue is in the range of about 5 μm to about 1000 μm.

8. The treatment system of claim 1 , wherein the optical system comprises an array of micro-lenses extending along a first direction and a second direction, and wherein the array of micro-lenses is configured to focus the at least one laser beam to the focal region.

9. The treatment system of claim 8 , wherein the at least one laser beam simultaneously impinges on the array of micro-lenses generating an array of focal regions.

10. The treatment system of claim 8 , wherein the optical system is configured to traverse the at least one laser beam from a first lens of the array of micro-lenses to a second lens of the array of micro-lenses.

11. The treatment system of claim 8 , wherein the laser system is configured to emit a plurality of laser beams, and wherein one or more beams of the plurality of laser beams impinge on one or more micro-lenses of the array of micro-lenses.

12. The treatment system of claim 1 , wherein the pigmented region of the tissue comprises a chromophore.

13. The treatment system of claim 12 , wherein the chromophore comprises at least one of melanin, tattoo inks, hemoglobin, sebaceous glands, subcutaneous fat, hair bulb, lipids in cell membrane, fat surrounding organs, vessels, or drug components.

14. The treatment system of claim 1 , further comprising one or more sensors configured to detect one or more of velocity and position of the treatment system relative to the tissue surface.

15. The treatment system of claim 14 , further comprising a feedback control configuration configured to:
receive data characterizing the one or more of velocity and position data detected by the one or more sensors; and
vary at least one of pulse duration, pulse frequency or pulse energy of the at least one laser beam.

16. The treatment system of claim 1 , wherein the laser system is configured to control a time interval between temporally adjacent laser pulses of the at least one laser beam such that a travel time for movement of the focal region from a first location in the tissue to a second location in the tissue that is less than the time interval.

17. The treatment system of claim 16 , wherein the time interval between the temporally adjacent laser pulses is less than 50 milliseconds.

18. A treatment system, comprising:
a laser system including at least one laser configured to emit at least one laser beam having a nanosecond pulse duration;
an optical system including at least one lens configured to focus the at least one laser beam to a focal region at a selected distance from a surface of a tissue, the focal region being configured to illuminate at least one portion of the tissue that includes a pigmented region of the tissue and an unpigmented region of the tissue;
a control arrangement configured to control the laser system and the optical system to cause an irradiation energy transferred to the focal region of the at least one laser beam at a wavelength that is selectively absorbed by the pigmented region of the tissue and to (i) generate a plasma locally at the pigmented region of the tissue when the focal region overlaps with the pigmented region, the plasma causing damage to the pigmented region of the tissue within the focal region, and (ii) avoid damage at the unpigmented region of the tissue when the focal region does not overlap with the pigmented region and overlaps with the unpigmented region,
wherein the optical system has a numerical aperture that is in the range of about 0.5 to about 0.9.

19. The treatment system of claim 18 , wherein the plasma is a thermionic plasma, wherein the generation of the thermionic plasma (i) causes damage to the pigmented region of the tissue within the focal region when the focal region overlaps with the pigmented region, and (ii) avoids a generation of the thermionic plasma at the unpigmented region of the tissue and avoids damage at the unpigmented region of the tissue when the focal region does not overlap with the pigmented region and overlaps with the unpigmented region.

Assignees

• Massachusetts Gen Hospital
• Blossom Innovations Llc

Inventors

• Anderson Richard Rox
• Manstein Dieter
• Chan Henry Hin Lee
• Zuo Vincent

Classifications

• A61B2018/00732

  Frequency · CPC title

• A61B2018/00702

  Power or energy · CPC title

• A61B18/042

  using additional gas becoming plasma · CPC title

• A61B2018/20553

  with special lens or reflector arrangement · CPC title

• A61B2018/20355

  Special scanning path or conditions, e.g. spiral, raster or providing spot overlap · CPC title