Device for tattoo removal and cosmetic method carried out using said device

Abstract

The invention relates to a novel device for removing tattoos. The device according to the invention uses a precisely controllable laser system using a novel endpoint detection process. The device allows a very effective tattoo removal while protecting the skin surface as much as possible. The tattoo removal method carried out by means of the device is thus quick but simultaneously very effective without unnecessarily stressing the skin of the person in question.

Description

[0001] Device for tattoo removal and cosmetic procedures performed with it

[0002] The present invention relates to a novel device for tattoo removal. The device according to the invention utilizes a precisely controllable laser system employing a novel endpoint detection method. The device enables highly effective tattoo removal while protecting the skin surface as much as possible. The tattoo removal procedure performed using the device is therefore quick but simultaneously highly effective, without placing unnecessary strain on the skin of the affected person.

[0003] Tattoos have enjoyed increasing popularity in Western societies since the 1990s at the latest. The proportion of tattooed people in the German population is increasing. In Germany, approximately 20% of adults have a tattoo (as of April 2018). The proportion of tattooed women and older people is also rising. In 2017, around half of all women between 25 and 34 years of age were tattooed. Tattooing is done by needle pricks in the skin, with a pigment being introduced into the skin at the same time. The pigment is intended to be deposited in the middle layer of the skin (dermis) in the fibroblast cell type. The tattoo is usually applied using a tattoo machine capable of 800–10,000 punctures per minute.

[0004] As tattoos have become increasingly popular, so has the desire for removal. Methods have been developed to remove unwanted tattoos from the skin. Many of these procedures use lasers to destroy the ink particles introduced into the skin. It has been found that removing tattoos is significantly more complex than the tattoo itself. In many cases, several sessions are necessary to remove the tattoos: in most cases, around 10 sessions are necessary over a period of two years. Unlike black tattoos, color tattoos are often not removed at all, or only partially; ink particles remain under the skin. In other cases, injuries occur, particularly burns, from the intense laser light. The reason for this is that the laser is moved manually over the skin: in many cases, this leads to uneven radiation of the skin.It is particularly difficult for the treating person to recognize when a particular dye particle has been sufficiently irradiated.

[0005] The state of the art for such methods is set out, among other things, in the following documents:

[0006] (1) Article: Tattoo removal using picosecond laser with fractional ablative support, July 30, 2019, 1:59 PM; Laser, radiofrequency, ultrasound, microneedling (cited in DPMA examination notice of September 23, 2024)

[0007] (2) DE 198 36 649 A1

[0008] (3) DE 69825447 T2

[0009] (4) DE 10 2006 054468 A1

[0010] There is therefore a need for new devices and methods for removing tattoos that overcome the disadvantages described above and enable effective tattoo removal.

[0011] It has now been found that the device described below has a significantly higher efficiency in tattoo removal and enables removal with maximum protection of the skin.

[0012] The device according to the invention contains:

[0013] 1 . at least one laser light source,

[0014] 2. an optical arrangement for the targeted control of the color particles under the skin surface with the laser beam,

[0015] 3. an application unit with an endpoint detection device,

[0016] 4. a control unit for controlling the device. The device may optionally contain one or more of the following elements:

[0017] 5. an optical device for the geometric distribution of the laser light (beam former),

[0018] 6. a beam splitter for generating two laser light beams as a treatment beam and as a fractionating beam,

[0019] 7. a motion sensor,

[0020] 8. a cooling option for the skin surface,

[0021] 9. a shock wave therapy unit for the skin,

[0022] 10. a device for applying a local anesthetic and / or for microneedling.

[0023] The device according to the invention is shown schematically in Fig. 1. The device consists of a base unit, which contains, among other components, the laser source. The device also includes an application unit, which ultimately applies the laser light to the skin. A connecting element is located between the base unit and the application unit, which, on the one hand, serves to guide the light into the application unit and, on the other hand, also transmits movement and position information as well as sensor signals back to the control unit.

[0024] A QS laser, for example, serves as the central laser light source. Such lasers based on Nd:YAG solids (or Er:YAG solids) are well known in the art. They are capable of generating ultrashort laser pulses in the nanosecond or picosecond range at wavelengths in the infrared range, for example, at 694, 755, 1064, 1320, or 1444 nm. The various wavelengths can be generated, for example, by ruby ​​lasers (694 nm) or alexandrite lasers (755 nm). Other wavelengths can be generated by dye lasers.

[0025] The laser power must be adjustable. In a preferred embodiment, a fiber laser serves as the laser light source. Such a fiber laser is a special type of solid-state laser. The doped core of a glass fiber (doped, for example, with erbium, ytterbium, and / or neodymium) forms the active medium in a fiber laser. It is therefore a glass laser with fiber optic properties. The laser radiation guided through the laser-active fiber experiences very high amplification due to its great length.

[0026] If other wavelengths need to be generated (e.g. in the treatment of colored tattoos), dye lasers can also be used, the wavelength of which is generally easy to adjust.

[0027] For the use according to the invention, two laser beams are used: a treatment beam for comminuting the color particles and a fractionation beam for firing small holes into the epidermis. These can be generated either from two laser sources or by beam splitting from a single laser beam. Preferably, only one laser light source is used to generate the treatment beam and the fractionation beam.

[0028] During the application, the treatment jet breaks down the color pigments so that they can be removed from the body independently, while the fractionation jet shoots small holes into the uppermost surface of the skin through which gases (e.g. water vapor) can escape from the skin (see explanation below).

[0029] The laser beam used to destroy the dye particles (treatment beam) is preferably shaped into a geometric form using optical devices. Laser beams are, by definition, point-shaped. Using suitable optical devices, the laser beam can be shaped into a geometric form so that the laser beam impinges on the skin surface and the underlying dye particles evenly. For example, the laser beam can be shaped into a round form with a diameter of 0.5–10 mm (preferably 2–7 mm). The laser beam can also have other shapes, such as square, triangular, or hexagonal. The edge lengths of these geometric shapes are in the range of 0.5–10 mm (preferably 2–7 mm). By shaping the laser light, it is possible to irradiate the skin surface in a mosaic-like, even and seamless manner, without leaving any partial areas unirradiated. Examples of this are shown in Fig. 2.For example, it's possible to divide a portion of the skin's surface into a mosaic pattern, similar to a chessboard, and have the laser illuminate the individual squares (areas) of the chessboard completely and homogeneously, one after the other. Similar options exist for other geometric shapes. The preferred geometric shape is a regular hexagon.

[0030] The optical elements contained in the application unit of the device according to the invention allow the laser beams to be applied successively to the individual areas of the skin surface and in this way ensure that the entire skin surface with the color particles located under the skin surface below the application unit is treated evenly by the laser beams.

[0031] The application unit also contains one or more sensors for detecting the movement of the application unit, e.g., in the form of an inertial measurement unit (IMU) or an optical unit, as is also known from smartphones or computer mice. These sensors allow the position and movement of the application unit relative to the skin surface to be determined and the laser light to be adjusted accordingly.

[0032] The application unit can, for example, evenly illuminate a skin surface of 5x5 cm, with one pass over all areas taking only a few seconds. To break down the color pigments, each area is irradiated once per pass with a laser pulse with a maximum fluence of 15 J / cm 2irradiated. To shoot the holes, an energy of approximately 90 mJ is needed per hole. The person operating the application unit can therefore move the application unit slowly and as evenly (fluently) as possible over the skin surface in order to cover the entire tattoo. The motion sensors ensure that the entire skin surface is treated evenly with the desired laser beams. Optionally, it is possible to emit a corresponding warning signal if the application unit moves too quickly. Furthermore, it is optionally possible to move the application unit fully automatically over the skin surface, e.g. by a robot.

[0033] Crucial to the inventive use of the device is the second laser beam, which is generated as described above either by beam splitting or in the form of a second laser light source. The second laser beam causes the creation of tiny holes in the skin (< 1 mm, typically approx. 0.2 mm). The heat generated during the color particle bombardment often leads to cavitation-based blistering in the skin. These cavitation-induced blistering in the skin is also described as "whitening" or "frostening" due to their appearance. The blistering prevents the laser beam from penetrating the skin, making multiple irradiation of a single particle impossible. The micro-holes created allow these gases to escape from the skin, thus preventing local pressure buildup in the epidermis, including the described "whitening" or "frostening" phenomena.The release of these generated gases therefore makes it possible to treat the same area of ​​skin multiple times in a single session, significantly reducing the number of sessions required to remove the tattoo. Furthermore, the creation of micro-holes reduces stress on the skin and promotes cellular regeneration, collagen formation, and the removal of damaged skin cells.

[0034] In an optional embodiment of the invention, the fractionation beam for generating the micro-holes is not applied simultaneously with the treatment beam, but rather at a different time, i.e., immediately before or after the treatment irradiation. In this embodiment, it can be advantageous to use two laser sources. However, a design with only one laser light source is also possible. A further special feature of the invention is the detection of the end point of irradiation. It has been found that laser irradiation of the dye particles in a tattoo literally causes these particles to burst. After the particles burst, they can be broken down by normal physiological processes; further irradiation is not necessary; the end point of the laser light irradiation has thus been reached.The destruction of the dye particles by bursting them leads, among other things, to an acoustic signal, which can be detected with various sensors. In addition to acoustic and photoacoustic sensors, pressure sensors can also be used. The change in the dye particles can also be perceived visually with appropriate magnification. The use of several different sensors is also possible.

[0035] The application unit of the device according to the invention therefore contains a control device with an acoustic, pressure, and / or optical sensor, which can detect bursting. Another option for detecting the end point of irradiation is a photoacoustic sensor.

[0036] This endpoint detection ensures that each skin area receives only as much radiation as is necessary to burst the particle - over-irradiation of skin areas (with the possible consequence of burns and scarring) is prevented.

[0037] The described endpoint detection using sensors is used primarily for calibrating the system (adapting to individual skin type, skin color, tattoo depth, tattoo ink type, etc.), as described below. Endpoint detection is typically also used throughout the entire irradiation process.

[0038] In further optional embodiments of the invention, cooling of the skin surface is performed parallel to the irradiation, e.g., through cold air therapy / contact cooling. Furthermore, shock wave therapy and / or microneedling can optionally be performed. Furthermore, it is optionally possible to apply a local anesthetic before or during the laser treatment.

[0039] Components of the device according to the invention

[0040] 1. Laser light source

[0041] The laser light source comprises a laser medium, a pump, and a resonator. The laser medium provides the atoms for emission and is supplied with energy by the pump. The resonator focuses the stimulated emission before it exits the laser light source. When using two laser light sources according to the invention, they can be of the same design and type, but different types of laser light sources can also be used.

[0042] Specifications of a possible laser source: Wavelength: 1064 nm, Repetition rates: 1-10 Hz, Maximum pulse energy: ~10 J (adjustable from 0.1 J to 10 J), Pulse duration: < 10 ns. Such laser light sources are commercially available (e.g., Iberoptics Q-Smart-850).

[0043] 2. Optical device for the geometric distribution of the laser light (beam former)

[0044] Beam shapers distribute the intensity and phase distribution of the laser light. Phase optics such as aspherical or freeform lenses, as well as diffraction optics, are often used for this purpose. Such beam shapers can shape the laser light beam on the tattoo into a geometric shape, such as round, square, triangular, or hexagonal. Such devices for distributing the laser beam are available commercially (e.g., Beam Shaper from PowerPhoton ics).

[0045] 3. Optical arrangement for targeted control of the skin surface (laser light transmission)

[0046] The laser beam is deflected in the desired direction by movable elements. Deflection is usually based on optical scanners or prisms. Such optical systems are available commercially, such as the galvano scanner from Canon, the polygon scanner from Möwe Optics, or the Pangolin scanner from Pangolin-Laser Germany.

[0047] 4. Application unit with motion detection and endpoint detection device

[0048] 4a. Application unit

[0049] The application unit contains the components that must be located in the immediate vicinity of the treatment site. These include, for example, the device for directing the laser beam, motion detection, control elements, sensors for endpoint detection, cooling elements, and a shock wave generator. It is typically a plastic housing that can be manufactured, for example, by injection molding or 3D printing.

[0050] 4b. Motion detection

[0051] Motion detection is achieved, as with an optical mouse, through a combination of a laser diode module, a miniature camera, and a signal processor. The signal processor compares consecutive images and calculates the required motion data from the differences. Such systems are commercially available, such as the ADNK-7550 from Avago Technologies.

[0052] If necessary, this data can be supplemented with additional motion detection features, such as an IMU. IMUs of this type, like those built into almost all smartphones, are also commercially available, such as the BMI260 (Robert Bosch GmbH).

[0053] 4c. Endpoint detection device

[0054] An acoustic, photoacoustic, pressure, or optical sensor detects the acoustic signal, the typical pressure wave, or the visually perceptible change (during) the destruction of the dye particle or the formation of the whitening / frosting. Acoustic sensors, such as those built into almost all smartphones, are commercially available as standard components for countless applications, such as the MEMS audio sensor from STMicroelectronics. Pressure sensors and optical sensors of this type are also commercially available.

[0055] Photoacoustic sensors and their functionality are described in Jaeger et al., Journal of Biomedical Optics 10(2), 024035 (March / April 2005).

[0056] 5. Control unit for controlling the entire device

[0057] All input signals and parameters are collected and processed on a computer. The resulting control signals are then forwarded to the appropriate components for execution. This could be a conventional PC or laptop, for example.

[0058] 6. Optional cooling option

[0059] Cooling can be achieved via air (evaporative cooling) or contact (conduction cooling) and is based on cryogenic gases. Liquid nitrogen or dry ice is often used to cool biological materials. The gas stream from the evaporating nitrogen or sublimating dry ice is delivered to the skin via tubes. All necessary components are commercially available.

[0060] 7. Optional shock wave therapy

[0061] In (acoustic) wave therapy, sound systems generate shock waves.

[0062] These are often generated by small masses that undergo rapid changes of direction and are introduced into the body through a contact surface. Such systems are commercially available, for example, enShock from Zimmer MedizinSysteme.

[0063] 8. Optional microneedling

[0064] Microneedling is a well-known cosmetic skin treatment in which very fine, sterile needles are moved across the skin's surface (epidermis). This creates desired micro-injuries that are intended to stimulate natural skin regeneration. This results in various effects: a) stimulation of blood circulation b) promotion of cell renewal c) production of collagen, elastin, and the body's own hyaluronic acid d) reduction of wrinkles, scars, and pigment spots

[0065] Microneedling uses a roller equipped with needles (dermaroller) or an electric device with a needle attachment (dermapen). Depending on the desired result, the needles are up to three millimeters long. They are intended for single use and are commercially available.

[0066] 9. Optional application of a local anesthetic

[0067] To avoid wound pain, it is possible to apply a local anesthetic (e.g., lidocaine) to the skin before or during treatment. This can be done using a roller-shaped applicator, for example.

[0068] Use of the device according to the invention

[0069] The device according to the invention is used as follows:

[0070] The treatment person places the application unit on the area of ​​skin where the unwanted tattoo is located. Typically, calibration is performed by pressing a start button. For this purpose, the laser beams, i.e., treatment beam and fractionation beam, are directed onto a first skin area, and the process is monitored by the sensor. The laser beam is initially set to a low power, and the skin area is irradiated with a laser pulse (<10 ns) so that the beam energy on the skin area is, for example, 0.1 J / cm 2If the acoustic, photoacoustic, pressure, or optical sensor detects the typical signal, i.e., noise, pressure change, or optical change, the beam is stopped and the applied energy is stored. If the sensor does not detect the typical signal, the laser power is increased, and the process is repeated. The power increase is carried out gradually until the typical signal occurs, with 15 J / cm 2 Radiation energy per laser pulse must not be exceeded for safety reasons. If the laser power reaches 15 J / cm 2, then it can be assumed that this skin area does not contain any tattoo particles. The described procedure is preferably performed several times, for example, two to ten times. The laser radiation energy required to remove a tattoo particle depends on several factors, such as skin type and color, depth of the tattoo, type of tattoo ink used, etc. The calibration process determines the average energy required to remove a particle with a specific beam of defined power. The average energy can be, for example, 5 J / cm 2 be.

[0071] After activating the device using the second start button on the base unit or on the application unit, the actual treatment begins. The laser beam generated in the base unit is directed to specific areas of the skin surface via optical devices. At the same time, a second laser beam is directed to the same areas to create the holes in the skin described above. The optical devices contained in the application unit, in particular mirrors, lenses, and prisms, ensure that the entire skin surface beneath the application unit is evenly treated. The laser beam, shaped into a geometric shape, scans each skin area one after the other. The irradiation time for each individual area is based on the beam energy determined during calibration. To compensate for natural fluctuations in individual factors, the energy determined during calibration is increased by 10–30% (preferably 15–25%).Each skin area therefore receives precisely the determined laser beam energy. For example, with a previously determined average required irradiation energy of 1.8 J / cm. 2 the actual irradiation energy used can be 2.2 J / cm 2 (i.e. +20%).

[0072] In an optional embodiment, endpoint detection is continuously performed during treatment by the corresponding sensors in the application unit. The sensors detect the bursting of dye particles in each individual area, and the optimal amount of radiation energy is automatically adjusted (i.e., without user intervention, the amount of radiation energy is increased until the sensor detects the characteristic signal). After a particle bursts, the laser beam is guided to the next area. This improved method allows for even more precise irradiation because irradiation can be stopped immediately after a particle bursts (i.e., the optimal amount of radiation energy is automatically adjusted throughout the entire irradiation process (the entire session)).Even in this embodiment, calibration as described above is useful: If no dye particles are present in a skin area, no acoustic signal will be detected.

[0073] At the same time, motion sensors within the application unit ensure that movements of the application unit relative to the body surface are detected. These movements are immediately reported to the control unit, which then calculates the changes in the areas to be irradiated and adjusts the laser beams accordingly using the mirrors, lenses, or prisms in the application unit.

[0074] It has been shown that the use of the device according to the invention makes it possible to treat a tattoo (regularly using the same ink particles) several times (up to six times) without interruption during a single session. This is particularly possible because very little skin irritation occurs due to the optimal radiation dose (and continuous cooling), and because the gases "escape" through the very small holes created by the second beam.

[0075] This results in almost complete tattoo removal after just a single treatment session, within a few weeks. Furthermore, virtually no skin injuries, especially no burns, are noticeable during or after the session. The micro-holes created in the skin by the second beam are virtually invisible and do not cause any side effects, such as inflammation. However, the use of a skin care product (e.g., a cream containing dexpanthenol) is recommended. Sensitive subjects may be administered a local anesthetic before or during the treatment.

[0076] The device according to the invention can also be used to treat other skin conditions, such as erythrocyte colitis, erythrocouperose, or pigmented lesions. The endpoint is preferably monitored using optical sensors. In most cases, however, endpoint detection is possible using acoustic or photoacoustic sensors. Body hair removal is also possible in a similar way.

[0077] Furthermore, the device according to the invention can also be used for skin tightening and rejuvenation. In this application, the treatment beam is not required, but only the fractional beam. This fractional beam creates, as described above, microscopic injuries (holes) in the skin's surface. This stimulates skin circulation and cell renewal. The resulting formation of collagen, elastin, and the body's own hyaluronic acid leads to a reduction in wrinkles, scars, and pigment spots, thus resulting in a firmer and more youthful-looking skin.

Claims

Patent claims: 1 . Device for removing tattoos on human skin, comprising - at least one laser light source, - an optical arrangement for the targeted control of the color particles under the skin surface, - an application unit with at least one sensor for endpoint detection, - a control unit for control.

2. Device according to claim 1, comprising either two laser light sources or one laser light source and a beam splitter for generating two laser light beams as a treatment beam and as a fractionating beam.

3. Device according to claim 1, comprising at least one beam former for the geometric distribution of the laser light for uniform irradiation of a round, square, triangular or hexagonal area of the color particles under the skin surface.

4. Device according to claim 1, comprising an adjustable laser light source which allows adjustment of the laser energy incident on the skin in the range of 0.1-15 J / cm 2 allowed.

5. Device according to claim 1, wherein the application unit contains an acoustic sensor, an optical sensor, a photoacoustic sensor and / or a pressure sensor for endpoint detection.

6. Device according to claim 1, wherein the application unit contains at least one motion sensor.

7. Device according to claim 1, wherein the application unit contains a cooling device for cooling the skin.

8. Device according to claim 1, wherein the application unit contains a shock wave unit for the skin.

9. Device according to claim 1, wherein the application unit contains a device for applying a local anesthetic and / or for microneedling.

10. A method for the cosmetic removal of tattoos on human skin by means of a laser beam, characterized in that sensors detect when the laser irradiation of a dye particle has caused it to burst and the laser irradiation is stopped after the bursting has been detected.

11. A method for the cosmetic removal of tattoos on human skin using a device according to claim 1, comprising the following steps: a) laser irradiation of a first tattooed skin area with a treatment beam of a first energy and irradiation with a fractionating beam under sensor control b) gradually increasing the laser power of the treatment beam until the sensor registers the signal of the dye particle bursting, c) repeating steps a and b for adjacent skin areas until all areas under the application unit have been irradiated, d) simultaneously or subsequently moving the application unit over the skin to irradiate the entire tattoo.

12. A method for cosmetically removing tattoos on human skin using a device according to claim 1, comprising the following steps: a) calibration of the laser power by laser irradiation of a first tattooed skin area with a treatment beam of a first energy and irradiation with a fractionating beam under sensor control, b) Gradually increasing the laser power of the treatment beam until the sensor registers the signal of the dye particle bursting, c) Optionally repeating step ab) two to ten times on different skin areas under the application unit, d) Saving the necessary average laser energy of the treatment beam for bursting the dye particles, e) Irradiating all skin areas under the application unit with 100 to 130% of the laser energy stored in step d) with simultaneous or time-delayed irradiation by the Fractional beam, f) Simultaneous or subsequent movement of the application unit over the skin to irradiate the entire tattoo.

13. The method according to claim 10, 11 or 12, wherein the dye bursting signal in step b) is an acoustic signal, a photoacoustic signal, an optical signal or a pressure signal.

14. The method according to claim 13, wherein the sensor for controlling dye bursting is an acoustic sensor, a photoacoustic sensor, an optical sensor or a pressure sensor.

15. The method according to at least one of claims 10 to 14, wherein the laser treatment is carried out simultaneously with a treatment beam and a fractionating beam.

16. The method according to at least one of claims 10 to 15, wherein cooling of the skin occurs during the laser treatment.

17. Method according to at least one of claims 10 to 16, wherein a shock wave treatment and / or microneedling is carried out during the laser treatment.

18. The method according to any one of claims 10 to 17, wherein a local anesthetic is applied to the skin before or during the laser treatment.

19. Use of the device according to any one of claims 1-9 for the treatment of skin conditions such as erythrosis colli and erythrocouperosis or pigmented lesions.

20. Use of the device according to at least one of claims 1-9 for skin tightening and rejuvenation or for hair removal.

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