Adaptive control of optical pulses for laser medicine

• US 20090137994A1
• Filed: 08/18/2008
• Published: 05/28/2009
• Est. Priority Date: 06/14/2004
• Status: Active Grant

• Current Assignee: Solta Medical, Inc. (Bausch Health Cos., Inc.)
• Original Assignee: Reliant Technologies, Inc. (Bausch Health Cos., Inc.)
• Inventors: Eimerl, David, DeBenedictis, Leonard C.
• Granted Patent: US 8,291,913 B2
• Time in Patent Office: Days
• US Class Current: 606/9
• CPC Class Codes: A61B 18/20 using laser
• CPC Class Codes: A61B 18/203 applying laser energy to the outside of the body
• CPC Class Codes: A61B 2017/00022 Sensing or detecting at the treatment site
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2018/00452 Skin
• CPC Class Codes: A61B 2018/00636 Sensing and controlling the application of energy
• CPC Class Codes: A61B 2018/20351 Scanning mechanisms
• CPC Class Codes: A61B 2018/20361 with redirecting based on sensed condition, e.g. tissue analysis or tissue movement

Abstract

Tissue is treated by irradiating it with a sequence of optical pulses that are directed in sequence to various sites on the tissue. During the irradiation sequence, one or more tissue properties are measured at a site(s) that has already been irradiated. These measurements are used to adjust the parameters of subsequent optical pulses in the sequence.

Claims

1. A method for automatically controlling treatment of tissue with optical pulses, comprising:

irradiating a first site in a portion of tissue with a first optical pulse;

following the irradiation, automatically making a measurement of a tissue property at the first site;

based on the measurement, automatically adjusting a parameter of a second optical pulse; and

irradiating a second site in the portion of tissue with the second optical pulse in order to provide treatment of the tissue at a pre-determined treatment level.

2. The method of claim 1, wherein the step of automatically adjusting the parameter comprises:

comparing the measurement of the tissue property with a predetermined value of the tissue property; and

based on said comparison, automatically adjusting the parameter of the second optical pulse in order to provide the treatment at the pre-determined treatment level.

3. The method of claim 2, wherein the predetermined value is a range of values for the tissue property.

4. The method of claim 2, wherein the predetermined value is a desired end-point of the pre-determined treatment, and the parameter of the second optical pulse is automatically adjusted so that, based on the measurement, the second optical pulse is expected to achieve the desired end-point of the pre-determined treatment.

5. The method of claim 1, wherein irradiating the first site with the first optical pulse and irradiating the second site with the second optical pulse both occur by laser scanning.

6. The method of claim 1, further comprising:

irradiating the first site with a first sequence of multiple optical pulses that includes the first optical pulse.

7. The method of claim 1, further comprising:

irradiating multiple sites with a first sequence of optical pulses, said irradiation including irradiating the first site with the first optical pulse.

8. The method of claim 1, wherein the parameter of the second optical pulse includes a parameter selected from the group consisting of an energy of the optical pulse, a duration of the optical pulse, a temporal shape of the optical pulse, a spatial shape of the optical pulse, a propagation direction of the optical pulse relative to the tissue surface, a focusing characteristic of the optical pulse, a polarization of the optical pulse, and a wavelength spectrum of the optical pulse.

9. The method of claim 1, wherein the tissue property includes a property selected from the group consisting of mechanical density, electrical capacitance, dielectric constant, birefringence, opacity, optical reflectivity, absorption, extinction, elasticity, water fraction, melanin fraction, hemoglobin fraction, oxyhemoglobin fraction, and fraction of foreign matter.

10. The method of claim 1, wherein the tissue property includes a temperature of the tissue.

11. The method of claim 1, wherein the step of automatically making the measurement of the tissue property at the first site comprises:

making a measurement of a change in the tissue property at the first site.

12. The method of claim 11, wherein the step of automatically making a measurement of the change in the tissue property at the first site comprises:

making a measurement of a change in the tissue property before irradiation of the site by the first optical pulse and after irradiation of the site by the first optical pulse.

13. The method of claim 1, further comprising:

irradiating other sites in the portion of tissue with other optical pulses;

following the irradiation, automatically making measurements of the tissue property at the other sites; and

taking a weighted average of the measurements, wherein the step of automatically adjusting a parameter of the second optical pulse is based on the weighted average of the measurements.

14. The method of claim 13, wherein:

the weighted average is an exponential weighted average.

15. The method of claim 13, wherein:

the weighted average is weighted according to time.

16. The method of claim 13, wherein:

the weighted average is weighted according to distance from the second site.

17. The method of claim 1, wherein the second site and the first site are the same site, and the first and second optical pulses irradiate the same site.

18. The method of claim 1, wherein the step of automatically adjusting the parameter comprises:

automatically adjusting the parameter according to an artificial intelligence algorithm.

19. The method of claim 1, wherein the step of automatically adjusting the parameter comprises:

applying a predetermined rule to the measurement; and

automatically adjusting the parameter according to the predetermined rule.

20. The method of claim 1, wherein:

the step of making the measurement of the tissue property comprises measuring two or more tissue properties; and

the step of automatically adjusting the parameter comprises automatically adjusting two or more parameters based on the measurements.

21. The method of claim 1, wherein the step of automatically adjusting the parameter comprises:

automatically adjusting the parameter according to a control algorithm.

22. The method of claim 21, wherein the step of automatically adjusting the parameter according to the control algorithm includes placing a constraint on the parameter.

23. The method of claim 21, wherein the control algorithm dithers the parameter for the subsequent optical pulses.

24. The method of claim 1, wherein the step of automatically adjusting the parameter comprises:

automatically adjusting the parameter according to an algorithm selected from the group consisting of a moving simplex algorithm, a neural net algorithm, and a fuzzy logic algorithm.

25. The method of claim 1, further comprising:

determining a characteristic of the tissue based on the measurement, wherein the step of automatically adjusting the parameter comprises automatically adjusting the parameter in response to the determined characteristic.

26. The method of claim 1, further comprising:

determining a characteristic of the tissue based on the measurement; and

storing the determined characteristic.

27. The method of claim 26, further comprising:

following irradiation with the second optical pulse, irradiating a third site in the portion of tissue with a third optical pulse;

accessing the stored characteristic of the tissue; and

automatically adjusting the parameter of a third optical pulse in response to the accessed characteristic.

28. The method of claim 1, wherein the measurement and the irradiation by the second optical pulse are separated by less than 1 second.

29. A device for providing a controlled tissue treatment with optical pulses, comprising:

optics for directing optical pulses through an active area of the device to at least one site within a portion of tissue;

a detection module for automatically making measuring measurements of at least one tissue property at the at least one site, the measurements being made in close proximity to the active area of the device; and

a controller coupled to the detection module for receiving the measurement and automatically adjusting a parameter of a subsequent optical pulse based on the measurement.

30. The device of claim 29, wherein the optics and the detection module are located within a handpiece.

31. The device of claim 29, wherein the detection module comprises a passive detection module.

32. The device of claim 29, wherein the detection module comprises an active detection module.

33. The device of claim 32, further comprising:

an auxiliary source for generating signals for the active detection module.

34. The device of claim 29, wherein the detection module comprises:

a fiber located within a handpiece; and

a detector coupled to the fiber and located external to the hand-piece.

35. The device of claim 29, further comprising:

a source for generating the optical pulses, wherein the controller automatically adjusts a parameter for the source.

36. The device of claim 29, wherein the controller automatically adjusts a parameter for the optics.

37. The device of claim 29, wherein the detection module automatically makes measurements of a tissue property selected from the group consisting of mechanical density, electrical capacitance, dielectric constant, birefringence, opacity, optical reflectivity, absorption, extinction, elasticity, water fraction, melanin fraction, hemoglobin fraction, oxyhemoglobin fraction, and fraction of foreign matter.