Device for tattoo removal and cosmetic procedures performed therewith

Abstract

Device for removing tattoos on human skin, comprising - at least one laser light source, - Beam formers, as optical devices for the geometric distribution of the laser light, - an optical arrangement for targeted control of the skin surface, - a handpiece with motion detection and an acoustic, optical or pressure sensor, - a control unit to control the entire device, - an optional cooling option for the skin surface, - an optional shock wave therapy unit for the treated skin, characterized in that the acoustic, optical or pressure sensor detects the end point of the irradiation by detecting the bursting of the dye particles of a tattoo.

Description

[0001] 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, yet highly effective, without undue stress on the affected person.

[0002] 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 the ages of 25 and 34 were tattooed. Tattooing is done by needle pricks into 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 performed using a tattoo machine capable of 800–10,000 punctures per minute.

[0003] 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, multiple 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 or are not completely removed; ink particles remain under the skin. In other cases, injuries occur, particularly burns, due to the intense laser light. The reason for this is that the laser is manually guided over the skin: in many cases, this leads to uneven irradiation of the skin.It is particularly difficult for the treating person to recognize when a particular dye article has been sufficiently irradiated.

[0004] The state of the art for such devices and methods is derived, among other things, from the following documents: (1) Article: Tattoo removal using picosecond laser with fractional ablative support, July 30, 2019, 1:59 PM; Laser, radiofrequency, ultrasound, microneedling (2) DE 198 36 649 A1 (3) DE 698 25 447 T2 (4) DE 10 2006 054 468 A1

[0005] There is therefore a need for new devices and methods for removing tattoos that overcome the disadvantages described above and enable effective tattoo removal.

[0006] 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.

[0007] The device according to the invention contains: 1) at least one laser light source, 2) Beam formers, as optical devices for the geometric distribution of the laser light, 3) an optical arrangement for targeted control of the skin surface, 4) a handpiece with motion detection and an acoustic, optical or pressure sensor, 5) a control unit for controlling the entire device, 6) an optional cooling option for the skin surface, 7) an optional shockwave therapy unit for the treated skin, where the acoustic, optical or pressure sensor determines the end point of the irradiation by detecting the bursting of the dye particles of a tattoo.

[0008] The device according to the invention is shown schematically in Fig. 1. The device consists of a base unit, which contains, among other things, the laser source. The device also includes a handpiece, which ultimately applies the laser light to the skin. A connecting element is located between the base unit and the handpiece, which, on the one hand, conducts the light into the handpiece and, on the other hand, transmits movement and position information, as well as sensor signals, back to the control unit.

[0009] 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.

[0010] 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 form 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.

[0011] 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.

[0012] 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 a single laser beam. Preferably, only one laser light source is used.

[0013] 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 skin surface through which gases (e.g. water vapor) can escape from the skin (see explanation below).

[0014] The laser beam used to destroy the dye particles (treatment beam) is shaped into a geometric form using optical devices. Laser beams are, by definition, point-like. Using suitable optical devices, the laser beam can be shaped into a geometric form, e.g., square, triangular, or hexagonal. The edge lengths of these geometric shapes are in the range of 0.5-10 mm (preferably 2 to 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 can be found in the Fig.2. For example, it is possible to divide a portion of the skin surface into a mosaic pattern similar to a chessboard, and have the laser illuminate the individual fields (areas) of the chessboard completely and homogeneously, one after the other. Similar possibilities exist for other geometric shapes. The preferred geometric shape is a regular hexagon.

[0015] The optical elements contained in the handpiece of the device according to the invention allow the laser beams to be successively applied to the individual areas of the skin surface and in this way ensure that the entire skin surface below the handpiece is evenly treated by the laser beams.

[0016] The handpiece also contains sensors for detecting its movement, e.g., in the form of an inertial measurement unit (IMU) or an optical unit, similar to those found in smartphones or computer mice. These sensors allow the position and movement of the handpiece relative to the skin surface to be determined and the laser light to be adjusted accordingly.

[0017] The handpiece can, for example, evenly illuminate a skin surface of 5x5 cm, with one pass across 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. Each hole requires approximately 90 mJ of energy to create the holes. The operator can therefore move the handpiece slowly over the skin's surface to cover the entire tattoo, while the sensors ensure that the entire skin surface is evenly treated with the desired laser beams.

[0018] Optionally, it is possible to send out a warning signal if the handpiece moves too quickly.

[0019] 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. These gases can escape from the skin through the created micro-holes, thus preventing local pressure buildup in the epidermis, including the described "whitening" or "frostening" phenomena.The release of these generated gases 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.

[0020] In an optional embodiment of the invention, the fractionation beam for generating the microholes 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 may be advantageous to use two laser sources. A design with only one laser light source is also possible.

[0021] Another 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 bursting, the particles can be degraded through normal physiological processes; further irradiation is not necessary. The bursting of the particles results in a signal that can be perceived acoustically and by pressure measurement, and is also visually visible with appropriate magnification. The handpiece of the device according to the invention therefore contains a control device with an acoustic, pressure, or optical sensor, with which the bursting can be detected.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.

[0022] The described endpoint detection by means of sensors is used in particular for the calibration of the system (adaptation to individual skin type, skin color, depth of the tattoo, tattoo color type, etc.), as described below, but can also be used during the entire irradiation process

[0023] In an optional embodiment of the invention, cooling of the skin surface is carried out in parallel with the irradiation, e.g. by cold air therapy / contact cooling, and / or shock wave therapy is applied. Components of the device according to the invention 1. Laser light source

[0024] 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.

[0025] 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 available commercially (e.g., Iberoptics Q-Smart-850). 2. Optical device for the geometric distribution of the laser light (beam former)

[0026] Beam shapers distribute the intensity and phase distribution of the laser light. Phase optics such as aspheric or freeform lenses, as well as diffraction optics, are often used for this purpose. Such beam shapers can shape the laser light beam into a geometric shape on the body surface, such as square, triangular, or hexagonal. Such devices for distributing the laser beam are available commercially (e.g., Beam Shaper from PowerPhotonics). 3. Optical arrangement for targeted control of the skin surface

[0027] 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. 4. Handpiece with motion detection and endpoint detection device 4a. Handpiece

[0028] The handpiece contains the components that must be located in close proximity to the treatment site. These include, for example, the device for directing the laser beam, motion detection, control elements, 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. 4b. Motion detection

[0029] Motion detection is achieved, similar to an optical mouse, through the 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.

[0030] If necessary, this data can be supplemented with additional motion detection, such as an IMU. IMUs of this type, which are built into almost all smartphones, are also commercially available, such as the BMI260 (Robert Bosch GmbH). 4c. Endpoint detection device

[0031] An acoustic, pressure, or optical sensor detects the typical endpoint noise, 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, like 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. 5. Control unit for controlling the entire device

[0032] 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. 6. Optional cooling option

[0033] 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. 7. Optional shock wave therapy

[0034] In (acoustic) wave therapy, sound systems generate shock waves. These are often generated by small masses that undergo rapid changes in direction and are introduced into the body through a contact surface. Such systems are commercially available, for example, enShock from Zimmer MedizinSysteme. Use of the device according to the invention

[0035] The device according to the invention is used as follows: The treating person places the handpiece on the area of skin where the unwanted tattoo is located. First, 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 a 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, 10 J / cm 2 J. If the acoustic, 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 2Radiation energy must not be exceeded for safety reasons. The described procedure is preferably carried out 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 for removing a particle with a specific beam of defined power. The average energy can be, for example, 2 J / cm 2 be.

[0036] After activating the device using the second start button on the base unit or on the handpiece, the actual treatment begins. The laser beam generated in the base unit is directed via optical devices to specific areas of the skin surface. In parallel, 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 handpiece, in particular mirrors, lenses, and prisms, ensure that the entire skin surface beneath the handpiece is treated evenly. The laser beam, shaped into a geometric pattern, 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 initially determined energy is increased by 10–30% (preferably 15–25%).Each skin area therefore receives precisely the determined laser beam energy, based on the previously determined average required irradiation energy of 1.8 J / cm. 2 the actual irradiation energy used can be e.g. 2.2 J / cm 2 (i.e. +20%).

[0037] In an optional embodiment, continuous detection is carried out simultaneously with the treatment by the corresponding sensors in the handpiece. The sensors detect the bursting of dye particles in each individual area and the optimal amount of radiation energy is set automatically (i.e., without any user intervention, the amount of radiation energy is increased until the sensor detects it). After a particle bursts, the laser beam is guided to the next area. This improved method allows for even more precise irradiation because the irradiation can be stopped immediately after a particle bursts (i.e., the optimal amount of radiation energy is set automatically 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.

[0038] At the same time, motion sensors within the handpiece ensure that any movement of the handpiece relative to the body surface is 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 handpiece.

[0039] It has been shown that the use of the device according to the invention allows a tattoo (regularly using the same ink particles) to be treated / irradiated several times (up to six times) during a single session without interruption. This is particularly true 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.

[0040] 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.

Claims

[1] Device for removing tattoos on human skin, comprising - at least one laser light source, - Beam formers, as optical devices for the geometric distribution of the laser light, - an optical arrangement for targeted control of the skin surface, - a handpiece with motion detection and an acoustic, optical or pressure sensor, - a control unit to control the entire device, - an optional cooling option for the skin surface, - an optional shock wave therapy unit for the treated skin, characterized by that the acoustic, optical or pressure sensor detects the end point of the irradiation by detecting the bursting of the dye particles of a tattoo. [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 uniformly irradiating a square, triangular or hexagonal area of 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] The device of claim 1, wherein the sensor contained in the handpiece is an acoustic sensor. [6] 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 by laser irradiation of a first tattooed skin area with a treatment beam of a first energy and irradiation with the fractionated beam under control of the sensor, b) gradually increasing the laser power of the treatment beam until the sensor registers the signal of the dye particle bursting, c) optionally repeat step t from two to ten times), d) Storage of the necessary average laser energy of the treatment beam for bursting the dye particles, e) Irradiation of all skin areas under the handpiece with the laser energy stored in step d) with simultaneous or time-delayed irradiation by the fractionating beam, f) optional cooling of the irradiated skin areas, g) optional shock wave application to the irradiated skin areas h) Moving the handpiece over the skin to irradiate the entire tattoo [7] Method according to claim 6, wherein the calibration of steps a) to c) is repeated throughout the treatment session. [8] A method according to claim 6 or 7, wherein the dye bursting signal in step b) is an acoustic signal, an optical signal or a pressure signal. [9] The method of claim 8, wherein the dye burst control sensor is an acoustic sensor, an optical sensor, or a pressure sensor. [10] A method according to claim 6, wherein steps a)-h) are repeated two to six times.

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