CN109788946B

CN109788946B - Selective skin treatment using laser equivalent intense pulsed light device

Info

Publication number: CN109788946B
Application number: CN201780038674.2A
Authority: CN
Inventors: Y·多麦克维特兹; I·舒斯特
Original assignee: Rumex Be Co ltd
Current assignee: Rumex Be Co ltd
Priority date: 2016-06-24
Filing date: 2017-06-22
Publication date: 2023-02-03
Anticipated expiration: 2037-06-22
Also published as: EP3474762A4; CN115998417A; CA3026197A1; EP3474762A1; IL263143B2; IL303752A; CN109788946A; IL263143B1; IL263143A; WO2017223331A1

Abstract

A cosmetic method of providing light treatment to skin tissue, comprising: providing an Intense Pulsed Light (IPL) source; inserting a band pass filter between the IPL source and skin tissue; the band-pass filter enables light in a selected wavelength range to pass through, and the average absorption coefficient of the band-pass filter is equivalent to that of the selected laser source; the method comprises activating and applying the IPL source to the skin tissue, wherein the filtering of the light impinging on the skin tissue provides a treatment equivalent to the selected laser source.

Description

Selective skin treatment using laser equivalent intense pulsed light device

Technical Field

The present application relates to light treatment applied to human skin tissue, and more particularly to light treatment using selective band-pass filters in intense pulse light devices.

Background

Optical energy radiation is a known means for the treatment of dermatological disorders. To achieve a clinical effect in the skin, the irradiated light energy is preferably absorbed in the skin.

Light absorption in the skin is dominated by three endogenous chromophores: water, melanin, and hemoglobin. A proper match between the wavelength or spectrum of wavelengths of light and the target chromophore may result in optical energy absorption, which may be clinically effected by one or more photothermal, photochemical or photomechanical effects. When light energy is irradiated onto the skin, the light scattering effect may affect the depth of penetration of the light into the tissue. This effect, if any, is more dominant in the dermis than in the epidermis due to the higher concentration of collagen fibers in the dermis. Generally, the amount of scattering is inversely proportional to the wavelength of light up to the mid-infrared region of the light energy. As in Anderson and Parrish, "selective photothermolysis: precision microsurgery by selective absorption of pulsed radiation "mention, science, 4/29 1983; 220 (4596): 524-7, selective laser therapy may be achieved by selecting the appropriate wavelength to the appropriate chromophore, by applying an energy pulse shorter than or equal to the thermal relaxation time of the target chromophore, and by delivering energy above a threshold to the target tissue, as described above. Various laser and Intense Pulse Light (IPL) devices use these principles to provide a wide range of optical treatments for skin disorders.

IPL devices emit polychromatic, incoherent, and non-collimated light in the spectral range of about 400nm to about 1,400nm, and are typically delivered in various pulse durations. Therefore, the selectivity of IPL is low, since different chromophores can be targeted in this range. One option to increase the selectivity of the light energy produced by the IPL is to use a filter. A cut-off filter is used at the lower end of the emission spectrum of the IPL device and a cut-in filter is used at the upper end of the emission spectrum. Such filters may improve process selectivity or reduce spurious wavelengths, which may put the patient at risk, such as ultraviolet light or increased overall heating, such as the presence of infrared components in the emitted light. Common medical IPL cut-off filters include 550, 560, 570, 590, 615, 645, 695, 755, and 780nm filters. The cut-off filter and the cut-in filter can be used together to create a so-called band-pass filter.

Band pass filters are provided by some vendors (e.g., alma Lasers, etc.), for example, providing IPL-based narrow spectral processing in the 500-600 nm range for treating vascular lesions targeted to larger blood vessels. Another narrow band-pass filter is provided in the range 550nm-600nm for skin regeneration. One of the problems with such filters is that they also remove part of the optical energy generated by the light source, which is the IPL light source, during the filtering process. Therefore, in order to produce a clinical effect by meeting the above threshold energy requirement, only a limited amount of spectra may be removed.

In the laser domain, vascular lesions are treated by targeting the intravascular chromophore of oxyhemoglobin, which has light absorption peaks at 418nm, 542nm and 577 nm. The most common vascular lasers are KTP,532nm, pulsed Dye Laser (PDL) 585nm-595nm, emerald 755nm, diode laser 940-980nm and Nd: YAG 532 or 1,064nm. PDL is known as the "dominant" vascular laser.

As mentioned above, the IPL light source may also be used for the treatment of vascular lesions, using a filter comprising at least one of these absorption peaks and removing damaging UV and/or infrared wavelengths that may cause collateral thermal damage. Two companies, lumenis and Palomar, provide such dual band filters. For example, in a vascular dual band filter, shorter wavelengths are used for smaller superficial blood vessels, while longer wavelengths are used for larger, deeper blood vessels.

Pigment damage has also been treated by laser treatment using lasers such as KTP (532 nm), ruby (694 nm), emerald (755 nm), etc., with melanin in the melanosome as the target chromophore, using various pulse durations, starting from milliseconds to picoseconds. IPLs can also be used for some pigmentation disorders, such as pigmentation disorders or solar nevi. Also, by selecting a filter that produces the appropriate spectral energy, the IPL-driven device can be used to treat at least some pigmented lesions as long as the spectrum is broad enough that a sufficient amount of energy density reaches the target tissue. However, the broader the spectrum, different chromophores can be targeted and selectivity can be reduced. Furthermore, to avoid the side effects of scarring or bleaching, short pulses may be required to limit the area or volume of any thermal effect in the targeted tissue. These short pulses may be in the nanosecond or less range, while the IPL provides pulses only in the millisecond range.

The flexibility of using a single light source IPL in a device for treating various types of skin disorders on various types of skin remains very attractive. Therefore, there is a need for a more advanced system to provide IPL-based processing with higher effective selectivity or higher absorbance, similar to the equivalent known laser wavelength it is designed to simulate.

Disclosure of Invention

In one aspect, a device for cosmetic treatment of vascular lesions on skin tissue, equivalent to a laser operating at a wavelength of 532nm, comprises: an Intense Pulsed Light (IPL) source, said IPL source being activatable; further comprising a band-pass filter that, when activated, substantially blocks all but one wavelength range of light emitted from the IPL source; when activated, the band pass filter allows transmission of light from the IPL source in the range of about 525nm to about 585 nm; the IPL with the band pass filter provides a cosmetic treatment equivalent to a laser with an operating wavelength of 532 nm.

In another aspect, there is provided a method of cosmetic treatment equivalent to a 532nm laser on a body vessel region, comprising: providing an Intense Pulsed Light (IPL) source; inserting a band pass filter between the IPL source and the body vessel region; said band pass filter is of a type that passes light substantially in the range of about 525nm to about 585 nm; the method further comprises activating the IPL source; filtering of the light impinging on the vascular body part provides a cosmetic treatment equivalent to a 532nm laser.

In another aspect, a cosmetic method of providing light treatment to skin tissue includes providing an Intense Pulsed Light (IPL) source; inserting a band pass filter between the IPL source and a body vessel region; the band pass filter passes light in a range of about 525nm to about 585 nm; the method further comprises activating and applying the IPL source to the skin tissue, wherein the filtering of the illumination on the skin tissue provides a treatment equivalent to a 532nm laser.

In another aspect, a band pass filter, equivalent to a 532nm laser illuminated on skin tissue, is configured such that light passing through the filter is substantially in the range of 525nm to 585 nm.

In a further aspect, a cosmetic method of providing light treatment to skin tissue includes the steps of providing an Intense Pulsed Light (IPL) source; inserting a band pass filter between the IPL source and the skin tissue; the band-pass filter allows light in a selected wavelength range to pass through, and the average absorption coefficient of the band-pass filter is equal to that of the selected laser light source; the method further comprises activating and applying an IPL source to the skin tissue, wherein the filtering of the illumination on the skin tissue provides a treatment equivalent to the selected laser light source.

In another aspect, a cosmetic method of providing an Intense Pulsed Light (IPL) source equivalent to the treatment effect of a selected laser light source includes determining, for a selected laser light source of a particular wavelength, an average absorption coefficient for the particular wavelength in skin tissue; and selecting a band-pass filter having a substantially equivalent average absorption coefficient in the skin tissue. The skin tissue may be one or more of: blood absorption and melanin absorption.

In another aspect, the IPL source further comprises a body portion comprising the IPL source and an opening in the body portion to receive one or more band pass filters, and wherein the one or more band pass filters are filters that pass different ranges of light from the IPL source to the skin tissue. The one or more band pass filters may be in one or more of the following ranges: 560-690nm;675-900nm;700-800nm;725-775nm;940-980nm.

In one aspect, a method of selecting an IPL light source having a band pass filter equivalent to a laser light source of a specified wavelength for use in providing cosmetic treatment of skin tissue, the method comprising the steps of: selecting a laser light source with a specified wavelength; activating the laser light source; directing a laser light source to a target; measuring an average absorption coefficient of the selected laser light in the target; storing the measured coefficients; selecting a band-pass filter; activating the IPL light source; measuring an average absorption coefficient of a band-pass filter selected in the target; comparing the measurement coefficients of the band pass filter with stored measurement coefficients of the selected laser light source; if the measurement coefficients substantially match, then it is determined that the selected laser light source and the IPL light source with the selected band-pass filter are equivalent. The target may be skin tissue.

In one aspect, a method of selecting an IPL light source having a band pass filter equivalent to a laser light source of a specified wavelength for use in providing cosmetic treatment of skin tissue, the method comprising the steps of: selecting a laser light source with a specified wavelength; activating the laser light source; directing the laser light source to a target; measuring an average penetration depth of the selected laser in the target; storing said penetration depth; selecting a band-pass filter; activating the IPL light source; measuring an average penetration depth of a selected band pass filter in the target; comparing the measured average transmittance of the band pass filter to a stored measured average transmittance of the selected laser light source; determining that the selected laser light source and the IPL light source with the selected band-pass filter are equivalent if the measured average penetration depths substantially match.

In one aspect, a band pass filter equivalent to a 595nm laser illuminated on skin tissue; the band pass filter is configured such that light passing through the filter is substantially in the range of 560nm to 690 nm. The light may be an IPL light source.

In one aspect, a band pass filter equivalent to a 755nm laser illuminated on skin tissue; the band pass filter is configured such that light passing through the filter is substantially in the range of 700nm to 800 nm. The light may be an IPL light source.

In another aspect, a device for cosmetic treatment of vascular lesions on skin tissue, wherein said device is the equivalent of a laser with an operating wavelength of 595nm, comprising an Intense Pulsed Light (IPL) source, said IPL source being activatable; a band-pass filter that, when activated, blocks substantially all but one wavelength range of light emitted from the IPL source; when activated, the band pass filter allows transmission of light from the IPL source in the range of about 560nm to about 690nm; the IPL with the band pass filter provides cosmetic treatment equivalent to a laser with an operating wavelength of 595 nm.

In yet another aspect, a device for cosmetic treatment of vascular lesions on skin tissue, wherein said device is the equivalent of a laser having an operating wavelength of 755nm, comprising an Intense Pulsed Light (IPL) source, said IPL source being activatable; a band-pass filter that, when activated, blocks substantially all but one wavelength range of light emitted from the IPL source; when activated, the band pass filter allows transmission of light from the IPL source in the range of about 700nm to about 800nm; the IPL with the band pass filter provides cosmetic treatment equivalent to a laser with an operating wavelength of 755 nm.

Drawings

Fig. 1 illustrates the absorption of blood by light of different wavelengths.

Fig. 2 shows the absorption coefficients shown in fig. 1 by a table.

Figure 3 graphically illustrates the absorption of melanin by different wavelengths of light.

Fig. 4 shows the absorption coefficients shown in fig. 3 by a table.

Fig. 5 graphically shows the ratio of the absorption coefficient of melanin to light in blood as a function of wavelength.

Fig. 6 graphically illustrates the penetration depth of light into tissue at various wavelengths.

Fig. 7 illustrates the relative efficiency of an IPL light source at different wavelengths.

Fig. 8 and 9 show in tabular form typical values for the optical absorption of different chromophores at different wavelengths.

Detailed Description

The absorption coefficient of light in tissue or chromophores is a function of wavelength. Referring now to FIG. 1, there is shown a plot of light absorption in whole blood as a function of wavelength for a "532 laser filter" shown in "solid line" and a "dye laser filter" shown in "dashed line". In this non-limiting example, it is assumed that the blood consists on average of about 70% oxyhemoglobin and 30% deoxyhemoglobin. It can be seen that the absorption level varies with wavelength.

Fig. 2 shows a table containing selected values derived from the graph of fig. 1. Alternatively, fig. 3 shows a graph of the absorption of light in melanin as a function of wavelength, and fig. 4 provides selected values from the graph of fig. 3. Figures 8 and 9 list typical values for optical absorption at different wavelengths for different chromophores. The average absorption calculations to be given below as examples are based on these values.

For example, as can be seen from FIG. 2, the blood absorption coefficient at a wavelength of 532nm is about 232l/cm. Thus, according to this aspect of the invention, a band pass filter for an IPL system may be provided in the range of 525 to 585nm, as shown in fig. 1 as a "532 laser filter" for vascular lesion treatment, and as shown in fig. 9, fig. 9 shows an embodiment of a wavelength range that may be selected to provide an equivalent average absorption coefficient provided by a laser. The average absorption coefficient refers to all wavelengths in this range in blood, equal to 232 1/cm, which characterizes the absorbance of 532KTP laser light in blood. Therefore, an IPL system with such a band-pass filter is expected to have tissue interactions on the skin similar to a 532nm laser and may be as effective as a 532nm laser in treating vascular lesions.

As another example shown in FIG. 2, a dye laser with a wavelength of about 595nm has an absorption coefficient of about 60/cm in blood. The average absorption coefficient value of the band pass filter between 560nm and 690nm has the same average absorption coefficient in blood as a dye laser, so, according to this aspect of the invention, an IPL system with a band pass filter of 560nm to 690nm, as shown in fig. 2, a "dye laser filter", can be used to treat vascular lesions.

As another example, referring now to FIG. 3, an emerald laser (755 nm) has an absorption coefficient of about 172l/cm in melanin, as shown in FIG. 3. For example, a band pass filter from 700nm to 800nm passes the spectrum with an average melanin absorption coefficient of 173l/cm, and thus, according to this aspect of the invention, an IPL system is provided having a band pass filter between 700nm and 800nm, which is equivalent to an alexandrite laser and is referred to herein as an "alexandrite laser filter". A band pass filter passing the spectrum of 675nm to 900nm may provide similar results.

Fig. 8 is a table of an embodiment having wavelength ranges that can be selected to provide an average absorption coefficient in an IPL device that is equivalent to an alexandrite laser. Such an IPL system may be considered to have the same or very similar clinical effect as an emerald laser for treating pigmentation lesions.

In accordance with another aspect of the present invention, an IPL system may be provided having an IPL handpiece with a permanently embedded filter configured to accommodate a band pass filter that transmits a spectrum of light having an average absorption coefficient that is approximately similar to that of a known laser, such as KTP,532nm, pulsed Dye Laser (PDL) 585nm-595nm, emerald 755nm, diode laser 800-810nm, and Nd: YAG 532, ruby 694nm or l,064nm and above.

In accordance with yet another aspect of the present invention, an IPL system having an IPL handpiece may be configured to accept different filters in accordance with the present invention such that a single handpiece may interchangeably deliver a spectrum having an average absorption coefficient similar to an equivalent known laser on a target tissue or chromophore. A device manufactured and sold by the assignee of the present invention, designated M22Universal IPL (Lumenis LTD) in israel, is one example of such a device that accepts different filters.

The average calculation of a series of absorption values associated with a certain spectrum passing through a band-pass filter as described above can be performed in different ways. In the above embodiment, the calculation of the average is a basic arithmetic mean calculation in which the "weight" of each wavelength is similar.

However, as shown in fig. 6, the penetration depth of light into tissue (e.g., skin) varies and is also a function of wavelength. Thus, according to another aspect of the invention, the average absorption coefficient of the spectrum passing through the band-pass filter according to the invention can be calculated based on a weighted average calculation.

Furthermore, due to the wavelength dependence of the penetration depth, spots at different depths in the skin will experience different effective wavelength intensity distributions. Generally, as the depth increases, the spectrum shifts to the red and mid-infrared directions. Thus, according to this aspect of the invention, an IPL system is provided having an IPL band-pass filter configured to deliver a spectrum having an average absorption coefficient of a target tissue or chromophore which is similar to the absorption coefficient of a known laser at a predetermined depth in the skin.

For example, on the skin surface, a emerald laser at 755nm has an absorption value of about 172l/cm in melanin, as shown in FIG. 4. As can be seen from fig. 3, the spectrum having an absorption value similar to that of the emerald laser in the melanin pigment on average may be a band pass filter of 700nm to 800 nm. It should be noted that different bandpass filter averages may also produce spectra with average absorption coefficients similar to that of emerald lasers, such as bandpass filters of 725nm to 775 nm.

As mentioned above, to achieve the desired clinical effect, it is also preferred to reach a critical energy threshold. Therefore, the band pass filter should be selected based on the performance and intensity of the lamp to provide not only a spectrum with a similar average light absorption in the target tissue or chromophore as with known lasers, but also at least a threshold energy to achieve a clinical effect. Turning attention now to the embodiment with respect to the target tissue depth in the skin, a emerald laser filter for pigment lesions, which is intended for the deeper melanin in the skin due to movement in the mid-infrared direction, may need to transmit a slightly different spectrum moving in the blue direction in order to keep the average absorption of the transmitted spectrum near 172/cm + at this deeper location.

In accordance with another aspect of the invention, the energy emitted by the lamp is also a function of wavelength, as shown in FIG. 7. The efficiency of the lamp is different at different wavelengths, thus irradiating and delivering different amounts of energy. Thus, as described above, a weighted average calculation may be performed to compensate for the uneven energy distribution of the lamp. An IPL system and a suitable band pass filter configured to transmit a spectrum having absorption coefficient values anywhere in or within the skin on a weighted average basis similar to the absorption coefficient values of known lasers in target tissues or chromophores, which is also an aspect of the present invention.

Fig. 5 shows the ratio of the absorption coefficient of melanin to light in blood as a function of wavelength. It can be seen that this ratio is higher than 10 in the wavelength range of 600nm to 900 nm. Thus, according to this aspect of the invention, the band pass filter of the invention may be configured to pass a spectrum of wavelengths in which the ratio of the absorption of light in melanin to the absorption of light in blood is at least higher than 10/cm. Ratios higher than 10/cm are expected to give good selectivity for treatment of pigmented lesions. According to another embodiment, the IPL system may be configured to deliver spectra at ratios greater than 20/cm, greater than 30/cm, greater than 40/cm, or greater than 50/cm to further improve selectivity. According to this and other aspects of the invention, a lamp having high brightness is configured to deliver a high energy flux, and therefore, a threshold energy sufficient to produce a clinical effect can be achieved even with a relatively narrow band pass filter.

One example of a suitable flash for implementing the present invention may be the flash structure described in U.S. provisional application serial No. 62/465,210, filed on 1/3/2017.

Claims

1. An Intense Pulsed Light (IPL) system for cosmetic treatment of vascular lesions on skin tissue, the system comprising an IPL source/lamp, wherein the system uses an activatable IPL to simulate the treatment effect of a specific laser for cosmetic skin treatment, the laser to be simulated having an operating wavelength of 532nm or 595 nm;

the system further includes band pass filters that each substantially block substantially all but one wavelength range of light emitted from the IPL source when activated and when interchangeably inserting light beams during operation;

wherein, when activated, the band pass filter allows:

transmission of light from the IPL source in the range of 525nm to 585nm, so as to provide a cosmetic treatment equivalent in absorption coefficient and/or penetration depth to a laser operating at a wavelength of 532nm,

transmission of light from the IPL source in the range 560nm to 690nm to provide a cosmetic treatment equivalent in absorption coefficient and/or penetration depth to a laser operating at 595 nm.

2. The system of claim 1, wherein the IPL source further comprises a body portion including the IPL source and an opening in the body portion to receive the band pass filter.

3. The system of claim 1, having a handpiece configured to interchangeably receive the band pass filter.