Surgery – Instruments – Light application
Reexamination Certificate
1998-10-23
2001-03-06
Dvorak, Linda C. M. (Department: 3739)
Surgery
Instruments
Light application
C606S013000, C606S017000, C607S089000
Reexamination Certificate
active
06197020
ABSTRACT:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and method of laser treatment of subsurface cutaneous tissue for the purpose of effecting a tightening of the skin and reducing wrinkles without significantly altering the epidermis.
Pulsed CO
2
lasers, erbium lasers, holmium lasers, and other infrared lasers are being used clinically to remove the epidermis and superficial reticular dermis for the purpose of laser resurfacing. Besides removing the superficial layers, there is often a significant contraction of the skin associated with these laser resurfacing technologies. This skin tightening is due to sufficient, but not excessive dermal collagen heating by the laser, and it is as important to patient satisfaction as the more youthful epidermis (skin surface) appearance achieved by laser resurfacing.
Unfortunately, in order to achieve this skin tightening, it has been necessary to remove the epidermis with the laser. This results in a raw skin surface that is unsightly, and that requires extensive wound care for weeks. Attempts to reduce these unwanted morbidities by using lasers for resurfacing that do not have as much collateral thermal damage result in inadequate tightening of the skin. For example, a pulsed CO
2
laser of 100 microseconds or so duration (e.g., Tru-Pulse, Tissue Technologies, Inc., Albuquerque, N. Mex.) cause less postoperative erythema, swelling, and discomfort than pulsed CO
2
laser of one millisecond pulse duration (e.g., Nova-Pulse, Luxar, Inc., Redmond, Wash.), but they do not tighten the skin as much as the longer-pulsed CO
2
lasers.
Wrinkle removal by pulsed infrared lasers during resurfacing is a result of removal of the epidermis and reticular dermis at the same time. Skin tightening requires deeper thermal effects than wrinkle removal. Thus attempts to reduce postoperative erythema, pain and swelling by doing a more superficial resurfacing do not result in adequate skin tightening.
Prior art (e.g., U.S. Pat. Nos. 4,976,709 and 5,484,432) attempts to selectively treat subsurface collagen without damaging the surface have been primarily related to corneal treatment (laser thermal keratoplasty) for corrections of refractive errors using infrared wavelength greater than 1.8 micron. Moreover, treatment parameters identified were selected so as to avoid a cicatrix which might impair the transparency of the cornea. For example, preferred embodiments included small (<2mm in diameter) spot size, short pulse duration (0.1 sec), a fluence up to 100J/CM
2
and non-contact delivery means.
Contact handpieces and non-contact delivery means for laser treatment of the eye have included designs which allow for surface-sparing of the ocular tissues, but delivery of a photocoagulation to internal tissues such as the ciliary body in glaucoma management. In U.S. Pat. No. 5,514,125, for example, a contact handpiece for delivery of laser energy to the ciliary processes in glaucoma is described. It features a fiberoptic distal member separated from a focusing lens at the contact tip for the purpose of reducing scatter of the laser energy.
Controlled subsurface laser energy also can be used to remove hair, tattoos and varicose veins. A contact subsurface laser energy delivery system that can target the follicle and not damage the sebaceous glands and sweat glands and the skin between the hairs would be advantageous. Further as system for removing tattoos and treating varicose veins by the subsurface application of laser energy is desirable.
SUMMARY OF THE INVENTION
It is an object of the present invention to effect a significant tightening (contracture) of the skin without appreciable damage to the epidermis.
Accordingly, it is another object of the present invention to increase skin tone by effecting a contracture of the skin without affecting the overlying epidermis.
It is a further object of the present invention to reduce wrinkle formation by treating the underlying dermis without damage to the epidermis.
It is an object of the present invention to use an effective laser modality for skin tightening and wrinkle elimination which can be done without causing temporary disability to the patient.
It is a further object of the present invention to allow for repeated laser treatments as often as necessary to maintain skin tone and surface smoothness.
It is another object of the invention to provide a handpiece for contact delivery of infrared laser energy using treatment parameters determined to accomplish the foregoing objects of the invention.
It is another object of the invention to provide a variable focus handpiece for contact delivery of laser energy wherein the variable depth of laser treatment is achieved by varying the distance between the focusing lens and the tip of the fiberoptic bundle.
It is another object of the invention to provide a method and apparatus for the delivery of subsurface laser energy to remove unwanted hair.
Still another object of the invention is to provide a method and apparatus for for the subsurface delivery of laser energy to remove tattoos.
Yet another object of the invention is to provide a method and apparatus for the subsurface delivery of laser energy to treat varicose veins.
In accordance with the invention, briefly stated, the present invention provides for photocoagulation of the dermis that spares the epidermis. For this domain of wavelengths, for example, the exact combination of parameters selected for power setting and spot size must deliver more than 100J/CM
2
of laser energy fluence. With respect to pulse length, the pulse duration must be in excess of the thermal relaxation time of dermis (i.e., greater than 60 milliseconds) unless the laser delivers a train of short pulses (“micropulses”) wherein the duty cycle selected results in an interval between pulses of less than approximately 60 milliseconds. For a given fluence, the pulse duration selected must be adequate to raise the temperature of the dermis to approximately 70° C. yet spare the epidermis.
REFERENCES:
patent: 4976709 (1990-12-01), Sand
patent: 5057104 (1991-10-01), Chess
patent: 5192278 (1993-03-01), Hayes et al.
patent: 5282797 (1994-02-01), Chess
patent: 5344418 (1994-09-01), Ghaffari
patent: 5507790 (1996-04-01), Weiss
patent: 5660836 (1997-08-01), Knowlton
patent: 5735844 (1998-04-01), Anderson et al.
patent: 5928223 (1999-07-01), Shimizu
patent: 5964749 (1999-10-01), Eckhouse et al.
Dvorak Linda C. M.
Seidel Gonda Lavorgna & Monaco, PC
Sublase, Inc.
Yarnell Bryan K.
LandOfFree
Laser apparatus for subsurface cutaneous treatment does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Laser apparatus for subsurface cutaneous treatment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Laser apparatus for subsurface cutaneous treatment will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2534300