Surgery – Instruments – Light application
Reexamination Certificate
2001-08-27
2004-01-27
Gibson, Roy D. (Department: 3739)
Surgery
Instruments
Light application
C606S013000
Reexamination Certificate
active
06682524
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority of German Application No. 198 52 948.1, filed Nov. 12, 1998 and International Application No. PCT/EP99/05888, filed Aug. 11, 1999, the complete disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
a) Field of the Invention
The invention is directed to a handpiece for cosmetic treatment of skin surfaces, by which a laser beam is directed to a selected skin area which is subjected to the action of the laser beam. The invention is further directed to a method for cosmetic treatment of skin surfaces while operating a handpiece of the type mentioned above.
b) Description of the Related Art
Lasers are currently used the world over for cosmetic treatment of the skin, primarily of vascular and pigmented lesions, e.g., for removal of port-wine stains and tattoos, for skin resurfacing and also for hair removal. Usually, short laser pulses with a pulse duration in the nanosecond to millisecond range are introduced into the tissue for this purpose. Treatments of this kind serve primarily to improve the quality of life of the patient and are generally of a cosmetic nature.
The equipment for carrying out such treatments essentially comprises a laser radiation source and a handpiece which is used for directing the beam emitted by the laser radiation source onto the skin area to be treated.
In order to achieve a lightweight construction of the handpiece and thus to enable the freest possible handling of the handpiece, the laser radiation source and handpiece are constructed as separate subassemblies, and the transmission of laser radiation from the radiation source to the handpiece is carried out by means of a movable beam guidance device. The beam guidance unit can be formed of a plurality of rigid transmission members interconnected by joints or may also be constructed as a flexible fiber optic system or in some other way.
The handpiece has an in-coupling element at the transition from the beam guidance unit and an emission surface for the laser beam is provided at the end of the handpiece to be directed to the skin. Often, there is a spacer which fixes the working plane and accordingly ensures that the cross section and intensity of the applied laser beam in the working plane correspond to the selected parameters.
For many dermatological applications, it is advantageous to cool the outer skin layers in order to prevent laser radiation damage. Various methods and devices are known for this purpose.
For example, it is common to apply cooling gel to the surface to be treated or the surface to be treated is cooled by a spray. However, it is difficult to influence the temperature on the skin and in the layers located immediately below it in such a way that the desired treatment effect is achieved on the one hand and laser radiation damage to the epidermis is extensively prevented on the other hand. A further disadvantage consists in that a local uniform cooling is not guaranteed.
U.S. Pat. No. 5,057,104 describes a method and a device for treating cutaneous vascular lesions in which the laser beam is guided by a stationary cooling container communicating with the skin segment to be treated. In this way, heat is removed from the skin area during treatment.
U.S. Pat. No. 5,735,844 discloses a device for hair removal in which an optically transparent lens through which the laser beam is directed onto the skin area to be treated is brought into contact with a cooling unit as well as with the skin. In so doing, the lens also removes heat during the treatment of the skin area in question, as was described above.
In the devices mentioned above, the large space requirement caused by the dimensions of the cooling means placed on the skin has proved disadvantageous. This constitutes a hindrance when treating small surfaces. Further, the heat conductivity of the available materials which are transparent for laser radiation is comparatively poor so that fast, optimal cooling cannot be achieved.
Another substantial disadvantage consists in that when positioning the outlet optics for the laser beam and the cooling device it is initially necessary to wait before irradiating with laser energy until the skin site to be treated has cooled optimally. This is particularly disadvantageous when treating a larger skin surface on which the laser radiation must be introduced in several adjacent skin areas. The treatment period is relatively long due to the fact that a dwell or holding time is required for cooling for each of these skin areas first and the laser irradiation can take place only then.
Also, post-treatment of the affected skin portions by means of temperature control is impossible with the known handpieces.
OBJECT AND SUMMARY OF THE INVENTION
Based on this prior art, it is the primary object of the invention to further develop a handpiece for cosmetic treatment of skin areas by means of laser radiation in such a way that a more efficient treatment is ensured while protecting the skin as far as possible.
According to the invention, a handpiece of the type described above is outfitted with a device for moderating the temperature of the selected skin surface before and/or after its treatment. Accordingly, it is possible for a skin surface to be cooled or heated, as required, immediately before treatment with laser radiation and also, if required, to subject it to post-treatment by supplying or removing heat.
In a handpiece by which the laser beam is directed successively to individual skin areas corresponding to the laser beam cross section and covering the selected skin surface in its entirety, there is at least one temperature-moderated contact surface laterally adjacent to the exiting laser beam. According to the invention, the distance between the laser beam and a contact surface of the type mentioned above is dimensioned in such a way that a first skin area on which the laser beam was previously directed and on which the laser beam has just acted is in contact with the contact surface at the same time that the laser beam is directed to a second skin area. Alternatively or in addition, there can be another contact surface whose distance from the laser beam is so dimensioned that it is in contact with a third skin area on which the laser beam is to act in the next step (while the laser beam is still simultaneously directed to the second skin area and the first skin area is still in contact with the first contact surface).
Similarly, additional contact locations can be provided at the handpiece and, while the laser beam is directed to and acts on the second skin area, these other contact locations are in contact with other previously treated skin areas and/or with other skin areas to be treated subsequently by means of moderating temperature.
In other words, the contact surfaces are positioned at the handpiece in relation to the laser beam in such a way that while the laser beam acts upon a skin area, at least one other skin area on which the laser beam had acted previously (before moving the handpiece) and/or on which the laser beam is to act subsequently (after the handpiece is moved) is in contact with a contact surface. In this way, the temperature of the individual skin areas is moderated in immediate preparation for the laser beam action and/or for purposes of post-treatment. The handpiece can therefore be advanced progressively from one skin area to another without delay.
In construction variants, the dimensions of the contact surface may be smaller or larger than the dimensions of the laser beam cross section. In this way, it is possible, for example, to moderate the temperature of a larger surface portion before treatment, so that only surface portions whose temperature has already been moderated are subjected to the action of the laser beam and safety is increased. Moderating the temperature of a surface that is smaller in comparison to the laser beam cross section can serve for a gentler treatment of certain skin areas.
According to the invention, the at least one contact surface is connected
Elbrecht Jens
Kuehnert Juergen
Seitz Bernhard
Zimmermann Gabriele
Asclepion Laser Technologies GmbH
Gibson Roy D.
Johnson Henry M.
Reed Smith LLP
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