PROCESSING DEVICE DERMATOLIQUE

The present invention relates to a dermatologic treatment device comprising a laser head adapted to pull a laser beam.

It is known to dermatological treatment devices, which are typically employed to provide a determined and localized heating of a target area corresponding to a wound of a patient, which comprises the dermal tissues, and this in order to accelerate wound healing. Such a

To ensure that such a healing effect occurs optimally, it is suitable that the laser shot heats the dermis tissue illuminated by it until they approach an optimum temperature (between 45 and 55 °c), but without exceeding a maximum temperature (of the order of 60 °c) which can cause burns or irreversible damage dermal tissue.

To determine the temperature of the dermal tissues during firing, broadening the pyrometer at dermatological treatment device. Such a device is for example disclosed in WO-PCT international 2011/080574 of the applicant.

Now, and to control the temperature of the skin at the target area of the laser shot, it is convenient to employ means for driving laser shot adapted to selectively enable and disable a laser shot.

It is known in the field of devices for dermatological treatment to control the amount of heat transmitted to the tissue using laser shot by limiting the duration of firing at a constant value. Thus a previous model of the applicant applies shots with constant power, e.g. 6w, according to a configurable amount of time from among two values: 10 or 13s. Now, such an approach neglects too many parameters, such as the variability of behaviors of the skin of a patient to another, and leads to too great a variability of the temperature reached. Two risks exist then: a temperature too significant skin is reached causing burns or, conversely, a temperature too low making the treatment ineffective. Should therefore provide means for driving laser shot more accurate.

The present invention overcomes these various disadvantages and proposes a means able to control the laser shot in accordance with the temperature of the skin and a duration varying firing.

The invention relates to a dermatologic treatment device comprising a laser head adapted to pull a laser beam toward a target area of a patient's skin, a pyrometer adapted to measure the temperature (T-) skin at said target area, a timer capable of measuring the duration (D.) of the firing of the laser, and a means able to selectively enable or disable a laser shot, wherein the control means is configured to disable the laser shot when the duration of the shot (D.) reaches a threshold duration in seconds (DS) as determined by the affine function of the form DS=(CT-t-b)/C., with T being the temperature (T-) measured skin, similar to a temperature objectively, b being an offset temperature and c is a coefficient of average heating of the skin.

Advantageously, the control means is further configured to deactivate the laser shot when the temperature

(A T) reaches a threshold temperature (CD).

The driving means is then configured to deactivate the laser since one of the two thresholds is reached, either that the temperature (T-) skin has reached the threshold temperature (CD) is that the shooting time has reached the maximum duration DS as determined by the affine function defines previously.

The invention also relates to a dermatologic treatment system, said system comprising a device as described above and means for interacting between said laser head and the area of skin to be treated, said interacting means being arranged to cooperate with said interlock means.

The invention further concerns a skin treatment method using a device or system as previously described.

Figure 1 graphic wherein the device according to the invention.

Figure 2 is a bar graph of the duration as a function of temperature.

Other features, details and advantages of the invention shall become apparent from the detailed description given below as a guide.

As illustrated in Figure 1, the dermatologic treatment device 1 includes a laser head 2, a pyrometer 6, 7 a timer and means for driving the laser head 8.2 is adapted to pull a 3 laser beam toward a target area 4 5 located on the skin of a patient. The radiating process intended to provide controlled heating of the skin 5 at the target area 4. the pyrometer 6 is adapted to measure the temperature T of the skin 5 at said target 4, is in line with the skin surface receiving the firing of the laser beam 3.7 the timer is adapted to determine the duration d firing of the laser head 2.8 the control means is adapted to control the configuration and operation of the laser head 2. it is thus responsible for activation or deactivation of the laser shot and most of the management of the associated security.

The control means 8 may be electronic, computer or a combination of both. The configuration of the drive means 8 is ensured, by wiring, or more typically, by a software program or that the control means 8 is adapted to execute.

The device 1 may further include a man machine interface 9. this human machine interface may allow an operator to configure the device 1 by indicating the desired settings and controls its use. In use of the device 1, the onset or activating a laser shot is typically initiated by an operator command. In contrast, to secure, the end or deactivation of the firing is controlled by the control means 8. and the maximum amount of energy supplied to the target area 4 remains permanently under the control of the drive means 8.

Advantageously, the laser beam has a wavelength of between 0, 2 and 8 μ π ΐ μΐη, preferably between 0.9 and 1.8 μΐη and particularly preferably between 1 and 1.6 mW.

Now, and in a preferred embodiment, the laser beam has a wavelength in the range of 1, 2 00 nm (P-. the ex. 1210 nm).

According to an advantageous feature, the control means 8 is configured to disable the laser shot upon onset of at least one of two conditions. A first condition is related to the temperature T, the target area 4 as measured by the pyrometer 6. the first stop condition of the laser shot is performed when the temperature T reaches a temperature threshold set top.

A second condition is related to the duration d of the laser shot as measured by the timer 7. the second stop condition of the laser shot is performed when the shooting time laser reaches a threshold time to SD.

The laser shot is stopped as soon as at least one of these two conditions, and thus the faster, takes place.

The temperature threshold ST is advantageously a constant.

According to a specific embodiment, the threshold temperature set top applied by the driving means 8 weighted the offset temperature (- b-CD) is less than or equal to the temperature coefficient of the objectively TO and heating means c is less than 2.2.

Advantageously, the temperature threshold ST is then between 50 and 56 °c, the average heating coefficient c is between 1.10 and 2.10 preferably between 1.30 and 1, 90, the offset b being between 2.5 and 4.5, preferably equal to 3.5 and the temperature objectively is between 53.5 and 59 °c, preferably equal to 56 °c.

Advantageously, the temperature threshold ST is equal to 50 °c, the average heating coefficient c is 1.6, the offset b is 3.5 and the temperature objectively is equal to 56 °c.

Here the temperature T is regularly measured by the pyrometer 6 and updated during the course of a laser shot. This value is updated temperature T, each updating, compared with the temperature threshold value set top to test the performance of the first condition.

The duration threshold Sd is advantageously a decreasing function of the temperature T. thus, the lower the temperature T is initially high and more Sd from the laser shot duration is short.

As regards the implementation of the two safeties (in connection with ST and DS respectively) inducing the deactivation of the laser, there are two possible scenarios.

In the scenario where it is the security about the temperature threshold ST that induces the deactivation of the laser, the temperature T is measured once at the beginning of the laser shot and is used, via said function, to determine a maximum duration the SD of the shot. The skin temperature is regularly measured from the starting time of the laser shot. As the skin reaches the threshold temperature (CD) and even if the shooting time has not reached the threshold of the SD, the firing of the laser is stopped (first safety).

In the second scenario, where it is the security related to the maximum duration of the firing which induces the deactivation of the laser, the temperature T is measured also once at the beginning of the laser shot and is used, again via said function, to determine a maximum duration the SD of the shot. The skin temperature is regularly measured from the starting time of the laser shot. Since the maximum duration of firing Sd is reached, and even if the skin temperature has not reached the threshold temperature, the firing of the laser is again stopped (second protection). Now, and as for the shooting time, it is contemplated the re-evaluate one or more times during firing. With this re-evaluation, it is possible to realize a tracking closest to any variation that may occur in the course of the laser shot and/or in the behavior of skin in response.

The function that determines the threshold time is advantageously an affine function of the form DS=(to head the Tb)/C., with the SD the duration threshold, T the temperature, a temperature objectively to verbs, b being an offset temperature and c is a coefficient of average heating of the skin.

Advantageously the coefficient c and the average heating temperature objectively to verbs are constants.

Thus calculated, assuming 1' 5 heating of the skin can be modeled by a linear model gain equal to the coefficient of heating means c, the duration threshold DS constitutes an estimate of the time required to the skin 5 to move from the temperature T to the temperature objectively to verbs. If everything is proceeding as intended, the second stop condition is performed when the skin 5 reaches the temperature objectively (less the offset temperature).

Figure 2 shows a diagram temperature T/duration D. in such a diagram can be shown an operating point of the skin 5 subjected to a laser shot and its evolution over time. A temperature limit set top determines the first stop condition of a laser shot. An operating point cannot be located above this limit set top horizontal. A time limit to SD determines the second stop condition of a laser shot. An operating point cannot be located to the right of the vertical limit.

It appears that the two termination conditions of the laser shot are closely related in that they contribute, together, to secure the device 1. thus all parameters, the first condition: CD, and the second condition: C., to verbs, must be considered and determined together, to cooperate effectively.

According to a first embodiment, the second condition, determining a threshold duration SD of the form DS=(CT-t-b)/C., employs a coefficient c is higher and a transistor outline objectively temperature below the threshold temperature hotel St. the temperature T of the skin follows then heating C. fastest curve 10, c is greater slope. The temperature objectively is you, lower temperature threshold at the St. it follows that the threshold time is determined equal to the SDL.

In such an embodiment, the temperature objectively you is just reached to the duration CDS, wherein the laser shot is stopped. Here it is the second condition, duration, which restricts the laser shot. The first condition, temperature, is here present that in emergency, in order e.g. to avoid overheating of the skin that can cause a burn. The operating points may be located within the grid area.

An example functional and usable for such an embodiment, uses the following parameters: a temperature threshold set top equal to 53 °c, an average heating coefficient c equal to 1.60, an offset β equal to 3.5 and a temperature objectively to verbs equal to 56 °c. This example is functional and used experimentally. However few incident encountered have lead to modify it.

According to a second embodiment, the second condition, determining a threshold duration SD of the form DS=(CT-t-b)/C., employs a coefficient c is smaller but objectively a temperature higher than the operating temperature of TO hotel St. the temperature T of the skin then follows a slower heating curve according the c 11, c is smaller slope. The temperature is objectively To2, greater than the threshold temperature hotel St. it follows that the threshold time is determined equal to sd2.

In such an embodiment, the temperature is not objectively to2, in principle, has not been reached. The rise in temperature is assumed slower and is accompanied by a threshold time, here Sd2, longer. A shot hard potentially longer. Herein the first condition, temperature, which limits the laser shot, and ends at the final period of df, corresponding to the reaching of the temperature hotel St. the second condition, duration, yet is as present and permits, if necessary, prolong the shooting time until the duration Sd2, increasing the chance of reaching the temperature hotel St. operating points may be located in the hatched area according to a first mode of hatching up to FB, which can thus extend, at most, to sd2 and include the hatched area according to a second mode of hatching.

This second embodiment thus advantageously increases, significantly, the likelihood of reaching the temperature threshold set top, which is then advantageously set to an optimum value processing. This leads to improved efficiency in that is thus taken into account the variability of the thermal behavior of a patient's skin to the other. This second embodiment provides a time increased to attempt to meet a temperature effective hotel St. thus, if a patient has a coefficient less than the coefficient heating heating means c, its slower thermal response is compensated by an increased firing time. This increases the chances of successfully treating such a patient.

An example functional and usable for such an embodiment, uses the following parameters: a temperature threshold set top equal to 50 °c, an average heating coefficient c equal to 1.6, an offset β equal to 3.5 and a temperature objectively to verbs equal to 56 °c. Heating the coefficient c is a coefficient means obtained by a measurement campaign performed on a patient population. The foregoing coefficient heating means c of 1.98 was determined by a population predominantly composed of healthy patients. The new coefficient heating means c of 1.6 is more realistic in that it is determined by a population predominantly composed of patients susceptible to treatment by the device 1.

The use of the threshold temperature set top, not as unwanted security but as a condition determining nominally stopping the laser shot leads to revise its value down. Conversely, the temperature objectively has been increased, to increase the duration threshold SD and thus the likelihood of set top temperature threshold.

The two stop conditions of laser shot of the device 1 are advantageously does not configurable by the operator, in order to avoid any risk of burning and/or ineffectiveness of the treatment.

However an ability to configure the temperature objectively To is advantageously implanted in the control means 8, to allow adjustment type constructor or maintenance, accessible only to authorized personnel and knowing the risks. However the latitude of configuring the temperature objectively To is strictly restricted to a limited range and, according to a variation of + / - 0.7 °c about the nominal value of TO.

Preferentially another security may still be implanted in the dermatologic treatment device 1. This safety observes the rate of change of the temperature T of the skin, as measured by the pyrometer 6 immediate stopping and controls a laser shot if this elevation of the temperature T of the skin is either too slow or too fast relatively to its theoretical value.

This enables to detect atypical behavior of the skin and thus avoid or lack of efficacy of treatment on a rise in the temperature too slow, or contrariwise a burn hazard in the event of temperature rise too fast.

The rate of change of the temperature T of the skin is determined by observing the variation of the measured temperature T of the skin as a function of time/of the duration D. this variation is regularly measured during use of the device 1 and compared to its theoretical value. This desired value, by resuming a linear model with d=ATs/C., becomes AT=C.D .Howe, as previously, is the slope of the course of the temperature T as a function of time d is equal to the coefficient of heating means c.

Also, as soon as the variation of the temperature vs. time is too low, or too high, relative to the value of the coefficient of heat retaining means c, the laser shot is immediately stopped.

Illustratively, it is considered that a value is too great or too small if it differs by more than 10% of its theoretical value.

The invention also relates to a system for dermatological treatment by laser beam, said system comprising a device as described above and means of interaction between said device and the target area to be treated, said interacting means being arranged to cooperate with said drive means.

More particularly, said interacting means may include an adhesive backing provided with identification means (e.g. RFID chip) and capable of being secured proximate the target area to be treated, and communicating with an interface (e.g.. radio frequency) in connection with said drive means.

Such means of interaction are known from WO international requests by the PTC and PCT WO 2007/080239 2008/107563 and hence not only will be described herein in more detail.

The invention allows implementation of a skin treatment method comprising the steps of

directing the laser beam of a device as described above on a surface of the target area of skin to be treated of a patient,

- measuring, using the pyrometer previously described, the temperature of the skin surface contained within its field of view, which skin surface is integrally included in the treated skin area by said device, and

said light source to said servo means so that the temperature of the treated skin area is between 45 and 60 °c.