APPARATUS AND COSMETIC METHOD FOR TREATING HYPERHIDROSIS

Abstract

A cosmetic method for treating a human body to reduce hyperhidrosis includes applying laser light energy to one or more portions of the human body in which the laser light energy is one or more of: about 450 nm, about 930 nm, about 970 nm and about 1060 nm. An apparatus for accomplishing this method includes a source of laser light energy and a controller for controlling the laser light source to apply laser light energy to target and disrupt sweat glands in the human body.

Claims

1. A cosmetic method of treating a human body to reduce hyperhidrosis comprising: applying laser light energy to one or more portions of the human body wherein the laser light energy is one or more of: about 450 nm, about 930 nm, about 970 nm and about 1060 nm.

2. The cosmetic method of claim 1, wherein the laser light energy is delivered one of: continuous or pulsed.

3. The cosmetic method of claim 2, wherein the pulse rate is 1 Hz.

4. The cosmetic method of claim 2, wherein the pulse rate is selected from between Hz and 3 Hz.

5. The cosmetic method of claim 1, further comprising the step of cooling the human body in the vicinity of the application of the laser light energy.

6. The cosmetic method of claim 2, wherein the time delay between pulses is between the TRT of fat cells and the TRT of sweat glands.

7. A cosmetic method of treating a human body to reduce hyperhidrosis comprising: applying laser light energy to one or more portions of the human body wherein the laser light energy is provided as bulk heating of the skin surface of the human body.

8. The cosmetic method of claim 1 further comprising the step of providing bulk heating of the skin surface of the human body one or more of: before, during and after the application of the laser light energy.

9. The cosmetic method of claim 8, wherein the bulk heating is provided by one or more of: laser light energy, IPL light energy, RF energy, microwave energy or ultrasonic energy.

10. The cosmetic method of claim 8, wherein the bulk heating is applied at about 400 to about 650 nm.

11. The cosmetic method of claim 9, wherein the bulk heating is applied at about 400 to about 650 nm.

12. The cosmetic method of claim 1, further comprising providing a handpiece to deliver the laser light energy and wherein the handpiece includes an open tip and a source of vacuum, and further comprising the step of drawing the skin tissue into the open tip prior to applying the laser light energy.

13. Apparatus for treating a human body to reduce hyperhidrosis comprising: a source of laser light energy; a controller for controlling the laser light source; wherein the controller causes the laser light source to apply laser light energy at one or more of: about 930 nm, about 970 nm and about 1060 nm to target and disrupt sweat glands in the human body.

14. The apparatus of claim 14, wherein the controller controls the laser light energy to be delivered one of: continuous or pulsed.

15. The method of claim 1, wherein the application of laser light energy has one or more of the following parameters: (a) fluence of 5-50 j/cm2; (b) pulse width of 10-60 ms; (c) number of pulses of 1-20; (d) repetition rate of 0.3-5 Hz; (e) laser wavelength of about 970 nm.

16. The apparatus of claim 14, wherein the controller controls the application of the laser light source to operate at one of more of the following parameters (a) fluence of 5-50 j/cm2; (b) pulse width of 10-60 ms; (c) number of pulses of 1-20; (d) repetition rate of 0.3-5 Hz; (e) laser wavelength of about 970 nm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG. 1 illustrates skin surface tissue and the relation of sweat glands to the skin surface tissue.

[0037] FIG. 2 illustrates a typical physiology of the relation of sweat glands within an area of fat cells.

[0038] FIG. 3 illustrates a number of spectral absorption characteristics of tissue components at various wavelengths of light.

[0039] FIGS. 4A and 4B illustrate the results of treatments using the apparatus and methods of the present invention on sweat glands.

[0040] FIG. 5 illustrates an exemplary handpiece that may be used with the method and apparatus of the present invention.

[0041] FIGS. 6A and 6B illustrate an example of the pulse selective profile of temperature differential effects on fat tissue vs. water soluble tissue components when a 1 Hz pulse is applied to the skin tissue, using wavelengths of 1060 nm and 970 nm respectively.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0042] In the present invention, a non-invasive treatment of hyperhidrosis is accomplished by means of an external laser source. The objective is to cause selective thermally induced necrosis and/or apoptosis of sweat gland while maintain the surrounding tissue intact. As mentioned above, there are several methods to obtain that objective. The key element to proper selective treatment is the relative absorption of electromagnetic radiation by the various tissue components. FIG. 3 presents plots A and B of the spectral behavior of light absorption for fat and water respectively. As can be seen in FIG. 3, around wavelengths 650 nm-660 nm there is an isosbestic point 300 between fat and water. In region 301, at wavelengths shorter than that of the isosbestic wavelengths, fat absorption is higher than water absorption. In region 302, at wavelengths longer than that of the isosbestic wavelengths, water absorption is higher than fat absorption. As will be explained in more detail below, according to one aspect of the present invention, selective sweat gland treatment in region 301 may be achieved by a bulk heating treatment mode.

[0043] Tissue bulk heating may be achieved by using a pulsed or a continuous wave laser. In this treatment mode, the entire bulk of the tissue will be heated homogenously to approximately the same temperature while treatment selectivity may be achieved due to the differences in the Damaging Temperature Threshold (DTT) which characterizes sweat glands versus the surrounding fat. Since the sweat glands' DTT is lower than that of fat, selectivity may be achieved by increasing the bulk temperature to a level which is higher than the DTT for sweat glands but lower than the DTT of fat.

[0044] By using the radiation wavelengths in region 301, the sweat glands which are surrounded by fat tissue by heating the surrounding fat layer are targeted. Thus, the fat tissue can be targeted and its temperature increased to a certain level that initiates necrotic and/or apoptotic processes in the sweat glands embedded in it, while leaving the dermis tissue at a lower temperature.

[0045] Irradiating the tissue with wavelengths in the region 301 of FIG. 3 will raise the temperature of fat faster than that of the sweat glands. However, since the sweat glands are encapsulated by fat tissue, heat will diffuse from that tissue to the gland and increase its temperature. By adopting an appropriate irradiation protocol, the bulk temperature may be elevated to a point which is above the sweat gland DTT but below the fat cells' DTT, leading to a selective treatment of sweat glands.

[0046] A waveband which favors absorption by fat compared to water, such as 400 nm-650 nm, may be used. In this case, low power continuous wave (CW) or continuously oscillating (or pulsed) radiation having relatively small peak power and substantially high repetition rate may be applied to the treated region. Gliding a laser beam producing head back and forth over a wide region in order to gradually and homogenously increase the targeted area temperature and maintain it certain level is commonly known and may be applied to treat the sweat glands as well. As before, applying cooling to the epidermal layer reduces the risk of adverse effects.

[0047] In contrast, in region 302, the sweat glands are targeted directly to increase their temperature to sufficient levels and for a sufficient duration. Since, in this part of the spectrum, the absorption of light in water is higher than is fat, the sweat glands' temperature will increase faster than in the surrounding fat layer. This enables a selective treatment which is based on non-homogenous heating of the target tissue and direct targeting of the sweat glands. In addition, the fatty layer which surrounds the water based sweat gland thermally isolates it from the environment and effectively increases its thermal relaxation time (TRT). Thermal relaxation time is the duration required for the heat generated by absorbed light energy within the targeted chromophore to dissipate to 50% of its value immediately after laser exposure. A longer TRT enhances the selectivity of the treatment as the sweat gland will maintain its elevated temperature for a longer time, increasing the probability of initiation of apoptotic and/or necrotic processes.

[0048] Based on the facts outlined above, when selecting the specific wavelength within region 302 with which to treat, the desire may be to use a wavelength that maximizes the absorption difference between fat and water. On the other hand, the desire is for the absorption in water not to be too high. This could result in high absorption of the radiation by the epidermis and upper dermis layers (small penetration depth), with very little energy penetrating to the deeper levels of the dermis, and not be enough to affect the sweat glands.

[0049] It appears that the optimal wavelength for such a treatment may be in the 930 nm-1030 nm band, preferably at approximately 970 nm. Therefore, according to an embodiment, one suggested procedure for treating the sweat glands is with a diode laser at approximately 970 nm, based on the above analysis. The absorption at these wavelengths of energy in water is preferential compared to their absorption in fat. This is illustrated in FIG. 3A which shows that 970 nm produces a greater differential absorption between fat and water (sweat gland contents) when compared, for example, to 930 nm or 1060 nm. 970 nm is capable of penetrating deep into the hypodermal layer and affect the water-soluble components on the way, such as the sweat glands. Due to the fact that, as mentioned above, the sweat glands are surrounded by thermal isolation tissue (in this case fat), which has lower absorption properties at this wavelength, relatively selective necrosis of the sweat glands can be achieved.

[0050] Thus, using approximately 970 nm may be seen as selectively targeting the sweat glands themselves over the surrounding tissue. However, as will be discussed below, differential absorption is not a panacea in and of itself, such that even lesser differentials may be useful in damaging sweat glands due to the morphological structure of water from the secretory cells embedded in fat layer, from, for example, bulk heating.

[0051] Another optional waveband in region 302 is 1030 nm-1200 nm, although it may be expected to have lower efficacy than 970 nm. However, turning now to FIGS. 6A and 6B, it can be seen that at 1060 nm, while the absorption at that wavelength in fat tissue is greater than that shown for 970 nm, it is not overly high and the absorption in the sweat gland is equivalent to that shown for 970 nm so that selectivity may also be achieved in this portion of the spectrum.

[0052] The 680 nm-910 nm waveband is another band, in region 301, that may be applied to sweat gland treatments, but that range may be expected to be more effective in the bulk heating of skin tissue as discussed herein

[0053] By providing selective heating of fat and the sweat glands, necrotic processes may be induced only in the sweat gland while leaving the surrounding tissue intact. Various pulse sequences using the parameters listed in table 1 were tested with a laser having a wavelength of 970 nm and indeed resulted in very selective damage to the sweat glands.

In the drawing sequence 400 of FIGS. 4A and 4B, FIG. 4A generally illustrates the effects of such a pulse sequence on a pig's skin one week after treatment and FIG. 4B one month after the treatment. Turning now to FIG. 4A, that figure shows a hair follicle in the central portion of the photograph of FIG. 4A with a hemorrhagic wound 404 (HT). FIG. 4A also shows necrotic dark-colored (in the photograph) sweat gland cells 402 (N) surrounded by lighter colored fat cells 403 (in the photograph). Turning now to the photograph of FIG. 4B, one month later this figure shows a hair follicle 408 (HF), surrounded by subchronic inflammation (shown by arrows 410 and 412) but notably that there remains no remnant of the sweat gland components in areas in which they were previously present. Thus, this sequence 400 of FIGS. 4A and 4B illustrates the selective inflammatory effect in the sweat gland can be observed (indicating a necrotic process) after one week, and the disappearance of the sweat gland after a month.

TABLE-US-00001 Parameter Value Fluence [j/cm2]: 5 to 50 Pulse widths [ms]; 10 to 60 Number of pulses: 1 to 20 Repetition rates 0.3 to 5 [Hz]:
Table 1 above provides an exemplary set of pulse sequences characteristics which may be used to treat hyperhidrosis

[0054] In order to reduce the risk of adverse effects such as burns on the epidermis to radiation absorption by melanin, local cooling may be employed during treatment. Such cooling may be accomplished using, for example, the built-in cooling mechanism provided by the chilled tip technology available in some products made by Lumenis Ltd. of Israel in its LIGHTSHEER and RESURFX product lines. Other cooling methods can be considered as well. Pre- and post-cooling further reduce side effects such as edema or pain, may provide partial anesthesia, and may reduce temperature-rise in the melanin-rich epidermis.

[0055] Cooling may be provided continuously or intermittently and may be applied during the treatment or in a combination of during the treatment and post treatment to minimize undesired skin response such as erythema, edema, purpura, without interfering with the mechanism of heat accumulation in the sweat glands. Topical cooling of skin surface during or after energy delivery to the tissue may avoid heat accumulation even in upper layer of dermis, contributing to the procedure safety and allowing more energy to be transmitted to the tissue as and if needed.

[0056] Further enhancement of treatment efficacy might be obtained when delivering the treatment by applying vacuum to the treated area. The handpiece illustrated in FIG. 5 is a device to deliver laser light energy; the handpiece includes an open tip and a source of vacuum, and the process of using it includes a step of drawing the skin tissue into the open tip prior to applying the laser light energy, such that the sweat glands may be drawn closer to the laser light source contained within the handpiece. The handpiece of FIG. 5 is described in US 2008/0119830, assigned to the same assignee of the present invention and the entirety of which is herein incorporated by reference or may be the Lightsheer HS laser device also made by the same assignee. An additional advantage of applying vacuum to the tissue may be vaso-constriction of the blood vessels, thus pushing the blood from the target area and further enhancing the absorption of the light energy from the laser energy source into the sweat glands rather than being absorbed in competitive chromophores.

[0057] While the foregoing has discussed wavelengths in the regions 301 for bulk heating and in region 302 for more targeted heating, the wavelengths do not need to be restricted to either one of the wavelengths or spectrums mentioned above, but may also be a combination of a mix and match of two or more of the above wavelengths or spectrums, from the same region 301 or 302 or from both regions, according to the planned treatment of affecting the sweat glands and/or the fatty components. Also, a combination of bulk heating and, as appropriate, pulsed treatments may be combined to achieve the desired effects of damaging the sweat glands. A programmed controller may be employed to control and sequence these different treatment parameters.

[0058] While the foregoing general discussion has been directed to treatment of axillar sweat glands, it is to be understood that other body parts may be treated with the present inventions, such as the soles, palms, forehead, back, chest, and groin, as well as in the treatment of bromhidrosis (foot odor) and osmidrosis (heavy sweat odor) in various parts of the human body.

[0059] Typically, for a chilled tip hand piece configuration, the hand piece will be positioned using a pick and place or gliding or painting, depending on the wave form used, while maintaining firm compression during the entire treatment.

[0060] In the pick and place method, the tip is picked up from the skin immediately after the pulse, moved to the next treatment location, and then lowered against the skin. In the gliding technique, the tip is kept continuously in contact with the skin and moved to the next treatment location immediately after the laser pulse, making sure that the sapphire tip is pressed toor in close contact withthe skin when the laser light is applied. In the painting technique, the operator may move the handpiece back and forth over the skin surface.