Device and method for regenerative therapy by high intensity laser therapy
A method of high intensity laser treatment for stimulating regeneration of living biological tissue in a patient by applying a pulsed laser beam to a skin of the patient in need of the treatment.
1. A method for treating selective tissue of a patient, the method comprising:
generating a pulsed laser beam from a pulsed laser source;
conveying the pulsed laser beam through an optical fiber into a focusing tip; and
applying the focusing tip onto the skin of a patient in order to focus the pulsed laser beam in the targeted tissue with a spot having a radius r;
the pulsed laser beam having a peak intensity fluence (PIF) of 0.1 to 1.0 (J/cm 3 ) 2 to the tissue, the peak intensity fluence defined by:
P
I
F
=
I
p
·
τ
on
·
E
10
·
r
3
·
α
·
τ
off
(
τ
on
+
τ
off
)
where I p is peak intensity of a pulse of the pulsed laser beam, E is energy of the pulse, τ on is duration of the pulse, τ off is duration between pulses, and α is water absorption coefficient (cm −1 ) at a wavelength λ of the pulsed laser beam.
2. The method of claim 1 , wherein peak power of the pulse is between 400 W and 50 kW, the duration of the pulse is from 1 to 500 microseconds and duty cycle of the pulsed laser beam is from 0.01% to 0.5%.
3. The method of claim 1 , wherein the wavelength of the laser beam is between 0.75 and 2.5 micrometers.
4. The method of claim 3 wherein I p is in the range of 5 kw/cm 2 to 25 kw/cm 2 , E is in the range of 0.03 to 10 J, τ on is in the range of 1 to 500 μsec, and duty cycle of the pulsed beam is in the range of 0.01% to 0.5%.
5. The method of claim 4 wherein E is in the range of 0.2 to 2 J.
6. The method of claim 4 wherein λ is in the range of 0.9 to 1.2 micrometers.
7. The method of claim 4 wherein λ is about 1.064 micrometers.
8. The method of claim 4 wherein the step of applying the focusing tip comprises pressing a curved focusing end surface of the focusing tip against the skin.
9. The method of claim 1 , wherein the tissue is joint cartilage and the pulsed laser beam stimulates a chondrogenic action on the cartilage.
10. The method of claim 9 , wherein the focusing tip focuses the pulsed laser beam to a spot in the tissue at a depth of between about 0.5 centimeter and about 10 centimeters from the surface of the skin.
11. The method of claim 9 , wherein the focusing tip includes a cylindrical element and a curved focusing end surface, the cylindrical element being between about 3 cm long and about 4 cm long and having a diameter of between about 1.5 cm and about 2.5 cm, the curved surface having a radius of curvature of between about 10 mm and about 100 mm.
12. The method of claim 9 wherein the step of applying the focusing tip comprises pressing a curved focusing end surface of the focusing tip against the skin.
13. The method of claim 1 , wherein the peak power of the pulse, the duration of the pulse and duty cycle of the pulsed laser beam are selected to produce a combined photomechanical and photochemical effect on the tissue.
14. The method of claim 1 , wherein the diameter of the spot on the tissue formed by the focusing tip is from 1 millimeter to 20 millimeters.
15. The method of claim 1 , further including a step of covering at least a portion of the focusing tip with a gel wherein the gel reduces an optical impedance mismatch between the skin and the focusing tip.
16. The method of claim 1 , wherein the step of applying the focusing tip comprises temporarily compressing the skin when applying the treatment.
17. The method of claim 1 , wherein a photomechanical effect induced by the pulsed laser beam stimulates a chondrogenic action on the said tissue.
18. The method of claim 1 , wherein a photochemical effect induced by the pulsed laser beam controls cell differentiation such that healthy hyaline cartilage tissue is regenerated.