Directional micropulsed liquid spray for cooling

Abstract

To provide a nozzle assembly for cooling a treatment area with a fluid.SOLUTION: A nozzle assembly (7) comprises a first fluid outlet (11) and a second fluid outlet (11) operable individually as well as simultaneously. The first fluid outlet and the second fluid outlet are arranged apart from each other in such a manner that a fluid covers a first portion (S1) of the treatment area if only the former is operated, and the fluid covers a second portion (S2) of the treatment area if only the latter is operated, wherein the fluid covers a third portion (S12) of the treatment area if both are operated. In these cases, the second portion is not fully contained in the first portion, and the third portion is not fully contained in the first portion and / or the second portion.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to systems and methods for cooling various surfaces, and more particularly to systems and methods for cooling the surface of human or animal tissue being treated with an energy-based medical device, such as a laser, intense pulsed light device, or radio frequency device. [Background technology]

[0002] Although only medical and biological applications are discussed below, the invention also relates to industrial or other applications where rapid cooling of a surface is required.

[0003] In medical applications in which energy is delivered to tissue for heating, coagulation, or destruction of various targets, non-specific heating of the tissue surface (e.g., the epidermis) is a common side effect. Energy-based medical devices include, for example, lasers, intense pulsed light (IPL) devices, or radio frequency (RF) devices. Hereinafter, terms such as "laser," "pulse," and "beam" may be used to refer to any form of such energy-based device.

[0004] Treatments using energy-based medical devices require the delivery of a certain amount of energy to achieve a desired effect on the target chromophore or target structure. For example, in laser hair removal applications, sufficient laser fluence (energy / area) must be delivered to the hair bulb to achieve its destruction, while simultaneously minimizing epidermal damage. Because many laser wavelengths, especially those that penetrate the skin surface, are absorbed by melamine (which is abundant in the epidermis), epidermal heating is an unavoidable side effect of many laser treatments. In many cases, the threshold fluence required to destroy the target chromophore or structure is very close to the fluence threshold for epidermal trauma. Furthermore, uncontrolled heating of the epidermis above its coagulation kinetics of 65-70°C for extended periods can result in severe epidermal damage or blisters, and can also lead to scarring and hypopigmentation. Cooling the superficial layers of the epidermis is necessary to avoid these complications while simultaneously allowing sufficient energy to be delivered to the target structure.

[0005] Exemplary applications in which high energy is used and cooling is necessary to avoid epidermal damage include laser hair removal and coagulation of venous and vascular lesions. In other applications, such as non-invasive fat reduction, relatively low energy densities are delivered during prolonged exposure to a laser, radiofrequency device, or another energy source, resulting in prolonged heating of subcutaneous fat to temperatures above 42°C. This results in apoptosis (death) of fat cells and loss of the fat layer. In these methods, epidermal cooling may be used to avoid prolonged heating of the epidermis, thus maximizing patient safety and comfort.

[0006] In energy-based medical device treatments, the problem of epidermal overheating is solved by cooling the epidermis before, during, and / or after treatment. An ideal cooling method should effectively reduce the temperature of only the superficial layers of the epidermis, since cooling of deeper layers would prevent the desired heating of the target structure / chromophore. In particular, if deeper tissue layers are also cooled, it would be necessary to deliver high energy to the target structure / chromophore to achieve the desired temperature.

[0007] Various types of cooling systems are commonly used in medical systems, where various cooling media are brought into contact with tissue surfaces. The most common methods include contact cooling with the cooled surface of a cooling device, cryogenic spray cooling, and cold air cooling.

[0008] Contact cooling using cooled glass or metal surfaces is commonly used, and such contact cooling achieves localized and rapid cooling. However, this method is inconvenient when cooling is required for extended periods of time, as prolonged exposure to the cold plate (which is typically kept cold by the active delivery of another cooling medium, e.g., a liquid coolant) can result in cooling of deeper tissue layers and cooling of the target structure. However, as noted above, cooling of deeper layers increases the energy required to destroy the target. Additionally, contact cooling methods can result in skin compression, which in some applications, for example, in the removal of vascular lesions, can affect the absorbance of target chromophores. Furthermore, contact cooling often results in cooling of areas that do not require cooling, thereby reducing cooling efficiency.

[0009] Cryogenic spray cooling is another commonly used method. In this cooling method, the cryogenic spray is sprayed immediately before the laser pulse is delivered, minimizing skin exposure to the cryogenic spray, which has been cooled to a very low temperature. This method is effective for epidermal protection when high fluences are used. However, side effects caused by excessive skin cooling, such as hypopigmentation and skin irritation, have been reported. For this reason, cryogenic spray is not well suited for cooling large areas, such as those required for hair removal treatments. In addition, cryogenic spray is also harmful to the environment, since it has a high global warming potential. Due to these safety hazards, the storage and distribution of cryogenic spray (the cooling agent used in it) is often complicated and expensive.

[0010] Cooling with cold air is often used in laser treatments, where the cold air is directed at the treatment area before and during laser treatment. A drawback of cooling with cold air is the relative inefficiency of the air medium for tissue cooling, thus requiring long exposure times. This can cause discomfort to the patient and can result in deep layer cooling (which, as discussed above, adversely affects the threshold fluence required for destruction of target chromophores).

[0011] Water-based sprays have traditionally been used primarily to moisten tissue in dental laser applications for debris removal and as an adjunct to more efficient ablation. However, water-based sprays have not been used specifically to cool skin surfaces, and generally speaking, to cool tissue surfaces. This is because commonly available liquid sprays, such as those used by dental lasers, operate continuously and therefore create a liquid film on the skin surface, which acts as a thermal barrier to heat transfer. In particular, when a liquid film is present, rapid evaporation of droplets no longer occurs, thus preventing effective cooling. To avoid the formation of an undesirable liquid film, the liquid must be in a continuous flow. In particular, the liquid must be constantly removed from the treatment area. While removal of liquid by suction is relatively easy in already wet, enclosed treatment areas, such as the mouth, it is completely impractical when attempting to cool large body surfaces. In addition, many dermatological applications, such as hair removal, skin tightening and fat reduction, have demonstrated a maximum of approximately 5000 cm 2 Or even 10,000 cm 2 Effective and uniform cooling of large skin areas up to 100 mm is required, which poses significant technical challenges when liquid spray cooling is used.

[0012] EP 3520728 A1 addresses at least the first of these problems with a micropulse spray for cooling. Specifically, this EP 3520728 A1 discloses an energy-based device for cooling tissue treated with, for example, a laser. The device includes a spray nozzle for generating an atomized liquid spray for the treatment area, the atomized liquid spray being based on a mixture of liquid and gas. The spray nozzle further includes at least one liquid outlet for discharging a liquid and at least one gas outlet for discharging a gas stream. The device further includes a liquid pumping means adjacent to at least one delivery means for delivering pressurized gas to the spray nozzle. Notably, the pumping means is configured to operate in a pulsed manner, which can help avoid the formation of a liquid film on the skin surface. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] European Patent Application Publication No. 3520728(A1) Summary of the Invention [Problem to be solved by the invention]

[0014] SUMMARY OF THE INVENTION The present invention is directed to an apparatus for cooling tissue being treated with an energy-based medical device, which overcomes at least some of the above-mentioned shortcomings of the prior art and further improves in other respects. [Means for solving the problem]

[0015] In a first aspect, the present invention relates to a nozzle assembly for cooling a treatment area with a fluid, the nozzle assembly including first and second fluid outlets that are independently and simultaneously operable, the first and second fluid outlets being spaced apart from one another such that when only the first fluid outlet is activated, the fluid covers a first portion of the treatment area, and when only the second fluid outlet is activated, the fluid covers a second portion of the treatment area, the second portion not being entirely contained within the first portion, and the first and second fluid outlets being spaced apart from one another such that when both the first and second fluid outlets are activated (simultaneously), the fluid covers a third portion of the treatment area, the third portion not being entirely contained within the first and / or second portions.

[0016] That is, the first and second fluid outlets are spaced apart from one another so that independent actuation of one of the fluid outlets causes the fluid to cover distinct portions of the treatment area. In this configuration, the portion of the treatment area covered by independent actuation of the first fluid outlet (i.e., the first portion) may not completely encompass (overlap) the portion of the treatment area covered by independent actuation of the second fluid outlet (i.e., the second portion). In some embodiments, the reverse is also true. In particular, in some embodiments, the first and second portions may be separate from one another, preferably separate and spaced apart from one another. For example, the first portion may have a first diameter d1, which may be defined as the maximum distance between two points (on the periphery) of the first portion. Similarly, the second portion may have a second diameter d2, which may be defined as the maximum distance between two points (on the periphery) of the second portion. Distance between the first and second parts TIFF0007738048000001.tif6150 can be defined as the minimum distance between any one point (on the perimeter) of the first part and any one point (on the perimeter) of the second part. TIFF0007738048000002.tif6150 may be at least 0.1 d1, 0.2 d1, 0.25 d1, 0.5 d1 or d1, and / or may be at least 0.1 d2, 0.2 d2, 0.25 d2, 0.5 d2 or d2. Additionally or alternatively, the distance TIFF0007738048000003.tif6150 may be at most d1, 2d1, 2.5d1, 3d1, or 5d1, and / or at most d2, 2d2, 2.5d2, 3d2, or 5d2. In some embodiments, a given upper limit may represent a lower limit, and vice versa. Any combination of these lower and upper limits, where meaningful, is expressly contemplated.

[0017] Additionally, the first and second fluid outlets may be simultaneously operable and spaced apart from one another such that, during such simultaneous operation, the fluid covers a portion of the treatment area (a third portion) that is not entirely contained within either the first portion or the second portion, or any combination thereof (e.g., a union thereof). That is, the first portion and / or the second portion may not entirely contain the third portion. On the other hand, in some embodiments, the third portion may entirely contain the first portion and the second portion. In other embodiments, the third portion may not entirely contain the first portion and / or the second portion.

[0018] Throughout this disclosure, a portion of the treatment area in the above sense should be understood as the smallest possible portion of the treatment area that is covered by (e.g., receives) (at least) 50%, preferably (at least) 70%, more preferably (at least) 90%, even more preferably (at least) 95%, and most preferably (at least) 99%, or even 100%, of the fluid emitted from the respective fluid outlet(s).

[0019] Therefore, the size and shape of the area receiving cooling can be adjusted, allowing areas of tissue that are not significantly heated during energy delivery to be bypassed, thereby minimizing the cooling power required and therefore maximizing cooling efficiency. The nozzle assembly can be used to efficiently cool tissue of various sizes and shapes with fluid, making the nozzle assembly particularly versatile as it can be utilized in a variety of treatments and / or applications.

[0020] In particular, the first and second fluid outlets are operable and spaced apart from one another such that, when simultaneously operated, the fluid covers portions of the treatment area located outside the first and / or second portions (and, optionally, no longer partially covers the first and second portions). In other words, the first and second fluid outlets are operable and positioned to reach portions of the treatment area that the fluid could not or would not reach using each of the first and / or second fluid outlets independently. This allows the present invention to increase or adjust the size and shape of the treatment area without adding structural complexity. By properly positioning the first and second fluid outlets and enabling them to operate simultaneously, the fluid can reach additional portions of the treatment area without the need for additional fluid outlets. Thus, the nozzle assembly can be used to efficiently cool tissue of various sizes and shapes, thereby enabling the nozzle assembly to be used in a variety of treatments and / or applications. At the same time, the nozzle assembly is compact and relatively simple from a structural standpoint in that it does not require additional fluid outlets to allow the fluid to cover parts of the treatment area that the fluid cannot reach independently upon operation of the first or second fluid outlets.

[0021] The present invention thereby not only overcomes the various drawbacks of previously known cooling systems, as discussed above, but also offers advantages over the spray nozzle disclosed in EP 3520728 A1. Because the spray nozzle disclosed herein does not operate two outlets simultaneously to provide fluid to portions of the treatment area that cannot be provided with fluid upon independent operation of the outlets, the spray nozzle may—generally speaking—effectively require a different number of outlets depending on the size and shape of the treatment area, which may make the spray nozzle less versatile in some applications, and less compact depending on the application / desired treatment area than the nozzle assembly of the present application. As a corollary, the fluid outlets of the present invention may generally be arranged differently than the outlets disclosed in EP 3520728 A1. In particular, the fluid outlets of the present invention may be configured to face in a different direction than the outlets disclosed in EP 3520728 A1, such that—during individual operation—they cover different portions of the treatment area than the outlets disclosed in EP 3520728 A1 (e.g., assuming the same distance between the spray nozzle or nozzle assembly, respectively, and the treatment area). As will become more apparent below with reference to Figure 7, the fluid outlets of the present invention may be arranged so that the portions of the fluid outlets covered by cooling fluid during individual operation, together with the portions of the fluid outlets covered by cooling fluid during simultaneous operation of two or more of the fluid outlets, provide as seamless coverage of the treatment area as possible. It is particularly notable that this allows voids to be left between the areas covered by the cooling fluid during individual operation of each fluid outlet, and that the fluid outlets may be positioned accordingly so that they point towards areas located further from the centre of the treatment area compared to, for example, the outlets disclosed in EP 3520728 A1.In contrast, the outlets disclosed in EP 3520728 A1 would need to be positioned to provide as seamless coverage of the treatment area as possible, when considered alone, of the portions covered by the cooling fluid during their individual operations. Thus, voids between these portions—and the corresponding placement of the outlets—are generally highly undesirable in EP 3520728 A1, as this would result in less seamless coverage of the treatment area.

[0022] In particular, a suitable arrangement of the first and second fluid outlets may be characterized by a center-to-center distance between the first portion and the first fluid outlet that is greater than a center-to-center distance between the first portion and the second fluid outlet, and / or a center-to-center distance between the second portion and the second fluid outlet that is greater than a center-to-center distance between the second portion and the first fluid outlet (e.g., when the nozzle assembly is used to treat a treatment area parallel to a line connecting the first and second fluid outlets). Throughout this disclosure, the center of a portion or area may be defined as the center of gravity or geometric center of the corresponding portion or area. That is, in particular, the first and second fluid outlets may be arranged in an X-shape (the first and second portions over which fluid is respectively covered during operation of these fluid outlets). That is, the direction of movement of the fluid emitted from the first fluid outlet is angled (or, in other words, oblique) relative to the direction of movement of the fluid emitted from the second fluid outlet. It should be understood that the direction of motion of the fluid emitted from the fluid outlet may be defined as the average direction of motion of the fluid, i.e., different portions of the fluid may move in different directions of motion, but an overall direction of motion is nevertheless said to be defined for the fluid as a whole, e.g., by averaging all of such different directions of motion.

[0023] For example, the first and second fluid outlets may be positioned such that, when both the first and second fluid outlets are activated (simultaneously), the fluid emitted from the first fluid outlet collides with the fluid emitted from the second fluid outlet at a distance from the treatment area, resulting in the fluid emitted from the first and second fluid outlets covering a third portion. Due to the collision, the fluids emitted from the first and second fluid outlets are at least partially deflected, i.e., such portions change their direction of motion, so that they ultimately reach portions of the treatment area different from those portions that would have been affected if the collision had not occurred. For example, the first and second fluid outlets may be spaced apart from each other such that the fluids emitted from the fluid outlets collide with each other above the treatment area. That is, the nozzle assembly may be positioned / held at a height above the treatment area. In this case, the first and second fluid outlets are positioned such that when both the first and second fluid outlets are activated (simultaneously), the fluid emitted from the first fluid outlet collides with the fluid emitted from the second fluid outlet at a distance from the treatment area, i.e., in a region located between the nozzle assembly and the treatment area. This should not be misunderstood as meaning that the nozzle assembly can only be used when positioned / held vertically above the treatment area. Because the fluid outlets can be activated using pressure (e.g., using pressurized fluid), the fluid outlets can emit their respective fluids in arbitrary directions, allowing the nozzle assembly to provide fluid used to enable cooling along any direction, and as a result, the nozzle assembly does not need to be positioned / held vertically above the treatment area, strictly speaking. Nevertheless, as will be readily understood by those skilled in the art, the placement of the fluid outlets may also depend on the desired / target distance between the nozzle assembly and the treatment area, which may depend on the desired / target distance between the energy-utilizing medical devices with which the nozzle assembly is to be used.This is especially true when the nozzle assembly is integrated into (or part of) an energy-based medical device.

[0024] The concepts of the present invention can be readily extended to any number of fluid outlets or nozzle assemblies including any such number of fluid outlets, for example, 3, 4, 6, 10 or any other number of fluid outlets.

[0025] For example, in addition to the first and second fluid outlets, the nozzle assembly may include a third fluid outlet that may be actuated independently and simultaneously with the first and / or second fluid outlets, the third fluid outlet may be spaced apart from the first and second fluid outlets such that when only the third fluid outlet is actuated, the fluid covers a fourth portion of the treatment area, the fourth portion not being entirely contained within the first and / or second portion (optionally vice versa), the first fluid outlet may be spaced apart from the second fluid outlets such that when both the first and third fluid outlets or only the first and third fluid outlets are actuated (simultaneously), the fluid covers a fifth portion of the treatment area, the fifth portion not being entirely contained within the first and / or fourth portion (optionally vice versa), and the third fluid outlet may be spaced apart from both the second and third fluid outlets Alternatively, the third fluid outlet may be spaced apart from the first and second fluid outlets such that when only the second and third fluid outlets are activated (simultaneously), the fluid covers a sixth portion of the treatment area, which sixth portion is not entirely contained within the second and / or fourth portion (optionally, the reverse is true), and the third fluid outlet may be spaced apart from the first and second fluid outlets such that when (all or only) the first, second and / or third fluid outlets are activated (simultaneously), the fluid covers a seventh portion of the treatment area, which seventh portion is not entirely contained within the first and / or second and / or fourth portion (optionally, the reverse is true).

[0026] Furthermore, in addition to the first fluid outlet, the second fluid outlet and the third fluid outlet, the nozzle assembly may have, for example, a fourth fluid outlet that can function separately and independently and simultaneously with the first fluid outlet and / or the second fluid outlet and / or the third fluid outlet. The fourth fluid outlet may be spaced apart from the first, second and third fluid outlets such that when only the fourth fluid outlet is activated, the fluid covers an eighth portion of the treatment area, which eighth portion is not wholly contained within the first portion and / or the second portion and / or the fourth portion (optionally vice versa); the fourth fluid outlet may be spaced apart from the first, second and third fluid outlets such that when both the first and fourth fluid outlets or only the first and fourth fluid outlets are activated (simultaneously), the fluid covers a ninth portion of the treatment area, which ninth portion is not wholly contained within the first portion and / or the eighth portion (optionally vice versa); and the fourth fluid outlet may be spaced apart from the first, second and third fluid outlets such that when both the second and fourth fluid outlets or only the second and fourth fluid outlets are activated (simultaneously), the fluid covers a ninth portion of the treatment area, which ninth portion is not wholly contained within the first portion and / or the eighth portion (optionally vice versa). the fourth fluid outlet may be spaced apart from the first, second and third fluid outlets such that when both the third and fourth fluid outlets or only the third and fourth fluid outlets are activated (simultaneously) the fluid covers an eleventh portion of the treatment area, the eleventh portion being not entirely contained within the fourth and / or eighth portion (optionally the reverse); and the fourth fluid outlet may be spaced apart from the first, second and third fluid outlets such that when the first, second and fourth fluid outlets are activated (simultaneously) the fluid covers a twelfth portion of the treatment area, the twelfth portion beingThe fourth fluid outlet may be spaced apart from the first, second and third fluid outlets such that the fluid covers a thirteenth portion of the treatment area (only) when the first, third and fourth fluid outlets are activated (simultaneously), and the thirteenth portion may not be entirely contained within the first and / or fourth and / or eighth portion (optionally the reverse), and the fourth fluid outlet may be spaced apart from the first, second and third fluid outlets such that the fluid covers a fourteenth portion of the treatment area (only) when the second, third and fourth fluid outlets are activated (simultaneously). The fourth fluid outlet may be spaced apart from the first, second and third fluid outlets such that when all or only the first, second, third and fourth fluid outlets are activated (simultaneously), the fluid covers a fifteenth portion of the treatment area, and the fifteenth portion is not entirely contained within the first and / or second and / or fourth and / or eighth portion (optionally vice versa).

[0027] Generally speaking, simultaneous operation of two or more fluid outlets can reach portions (additional portions) of the treatment area that cannot be reached by the individual operation of the fluid outlets. On the other hand, simultaneous operation of two or more fluid outlets generally no longer reaches portions that could be reached by the individual operation. In some embodiments, the first and second portions may not overlap, while the third portion may at least partially overlap with each of the first and second portions. In other embodiments, the first, second, and third portions may not overlap with each other at all. The same holds true when three or more fluid outlets are provided. For example, portions reachable by the individual operation of the fluid outlets may not overlap. Portions reachable by the simultaneous operation of two or more fluid outlets may at least partially overlap with portions reachable by the individual operation of each fluid outlet. Also, portions reachable by the simultaneous operation of two or more fluid outlets may at least partially overlap with each other. Additionally or alternatively, portions reachable by simultaneous operation of two or more fluid outlets may not be included in any combination of other corresponding portions reachable by simultaneous operation of two or more fluid outlets, hi other embodiments, all portions may be at least partially separate, or even completely separate.

[0028] Throughout this disclosure, overlap (where applicable) can mean at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or, in the case of complete overlap (e.g., when one portion is completely contained within another portion), 100% overlap. Conversely, additionally or alternatively, overlap (if applicable) can refer to at most 5%, at most 10%, at most 15%, at most 20%, at most 25%, at most 30%, at most 35%, at most 40%, at most 45%, at most 50%, at most 55%, at most 60%, at most 65%, at most 70%, at most 75%, at most 80%, at most 85%, at most 90%, at most 95%, or, in the case of complete overlap (e.g., when one portion is completely contained within another portion), 100% overlap. Note that these percentages may refer to any of the respective overlapping portions. As a result, it can be said that the percentages may vary depending on which portions they refer to, even when they label the same actual overlap. For example, if one of two overlapping portions is twice as large as the other, the latter is completely contained within the former, and the overlap is 100% when speaking of the latter, but only 50% when speaking of the former.

[0029] Generally, the portions covered by fluid when a single fluid outlet is operated may in principle be identical to and / or contained within one another, but the portions covered by fluid when that fluid outlet is operated (simultaneously) may not be completely contained within the portions covered by fluid when any of the multiple fluid outlets are operated individually, i.e., by operating two (at least two) fluid outlets simultaneously, portions of the treatment area that would not be covered by fluid by operating the two (at least two) fluid outlets separately and independently may be covered by fluid.

[0030] In some embodiments, the fluid used to cool the treatment area (i.e., the fluid covering different portions of the treatment area) may be an atomized liquid spray, e.g., a mixture of liquid and gas. The gas may be air, but may be any other suitable gas or gas mixture that is not flammable or harmful, e.g., to humans. In the following, the term "air" is sometimes used to refer to gas in general (but is not limited to air). An example of any suitable gas other than air is nitrogen. Similarly, the liquid may be water, but may be any other suitable liquid, liquid mixture, or solution that is not flammable or harmful, e.g., to humans. It has been found that atomized liquid sprays allow for good cooling without the hazards typically associated with cryogenic sprays and / or refrigerants used in cooling, e.g.

[0031] In some embodiments, at least one of the first fluid outlet and the second fluid outlet can be configured to emit an atomized liquid spray. That is, each fluid outlet can be an internal mixing outlet, thereby forming a nozzle assembly, at least in part, an internal mixing nozzle assembly. In particular, in such embodiments, each fluid outlet is configured to immediately emit the same type of fluid used to cool the treatment area, i.e., types of fluid that cover different portions of the treatment area, potentially facilitating targeted application of the atomized liquid spray. However, this is not essential, as will become clear below. For example, the first fluid outlet and / or the second fluid outlet can be configured to emit only one or more components of the fluid used to cool the treatment area.

[0032] For example, at least one of the first and second fluid outlets can be configured to emit gas that strikes the liquid, thereby creating an atomized liquid spray. (Note that this can be implemented in any variation or addition to the above, e.g., the first fluid outlet can be configured to emit an atomized liquid spray, while the second fluid outlet can be configured to emit gas that strikes the liquid, thereby creating an atomized liquid spray, or vice versa.) Due to the collision between the gas and the liquid, the liquid is atomized into small droplets, which form the spray. That is, each outlet can be an external mixing outlet, thereby comprising a nozzle assembly, at least partially comprising an external mixing nozzle assembly. In this case, the gas stream emitted from each fluid outlet (such fluid outlet exhibits a certain direction of motion when emitted from the respective fluid outlet) can flow along with the liquid, such that the resulting atomized liquid spray exhibits the direction of motion of the gas streams (combination, e.g., aggregated gas stream). (Note that the combination, e.g., aggregated gas stream, in turn exhibits a certain direction of motion, e.g., determined by the average direction of motion of the combination, e.g., aggregated gas stream.) In this manner, the direction of motion of the atomized liquid spray can be controlled by controlling the direction of motion of the gas streams (combination, e.g., aggregated gas stream). As a result, the area on the tissue surface impinged by the fluid (e.g., one or more portions of the treatment area) is (also) determined by the direction of motion of the injected / ejected gas stream. Note further that the geometry of each fluid outlet, particularly the orientation of the fluid outlet in three-dimensional space, determines the direction of the gas stream (combination, e.g., aggregated gas stream) emitted from the fluid outlet. This allows for precise control of where on the tissue surface the atomized liquid spray is applied.

[0033] In particular, at least one of the first and second fluid outlets may be configured to emit gas in pulses, preferably with a pulse duration of 10 ms to 5000 ms, more preferably with a pulse duration of 100 ms to 2000 ms. In this case, the pulse duration is defined as the time interval between two consecutive pulses. It should be noted that the pulsed application of the atomized liquid spray to the tissue resulting from at least one of the first and second fluid outlets configured to emit gas in pulses has the advantage that evaporation of the liquid can occur on the tissue surface between two consecutive pulses, thus avoiding "constantly" wet skin. Furthermore, particularly using the above-mentioned pulse duration range, the nozzle assembly may be operated to achieve a fine "micropulse" liquid spray with optimal liquid content, droplet size, and velocity, which together enable rapid evaporation of the droplets and thus rapid cooling of the tissue surface.

[0034] Additionally or alternatively, at least one of the first and second fluid outlets may be configured to emit gas at a pressure between 0.1 bar and 20 bar, preferably between 1 bar and 10 bar. This level of gas pressure may cause the gas stream (combined, e.g., aggregated gas stream) emitted from each outlet to have sufficient force to entrain liquid (e.g., provided in the form of one or more liquid droplets and / or liquid droplets) so that the direction of movement of the resulting atomized liquid spray essentially follows (and / or is essentially determined by) the direction of movement of the gas streams (combined, e.g., aggregated gas stream) as described above. Furthermore, the first and second fluid outlets may be configured to emit gas at different pressures within or beyond the aforementioned range. This allows for further fine-tuning of the direction of movement of the gas stream (combined, e.g., aggregated gas stream), i.e., steering of the gas stream.

[0035] As is clear from the above and as already alluded to near the beginning, the first fluid outlet and / or the second fluid outlet may be configured to immediately discharge the fluid used to cool the treatment area, i.e., the fluid covering the respective portion of the treatment area. However, this need not be the case. For example, the first fluid outlet and / or the second fluid outlet may (each) be configured to discharge a different fluid than the fluid used to cool the treatment area, i.e., the fluid covering the respective portion of the treatment area. For example, the first fluid outlet and / or the second fluid outlet may (each) be configured to discharge only one or more components of the fluid used to cool the treatment area, i.e., the fluid covering the respective portion of the treatment area (which may be, for example, an atomized liquid spray). Furthermore, in this case, the first fluid outlet and the second fluid outlet may be configured to discharge the same or different fluids.

[0036] Additionally, the nozzle assembly may include a liquid outlet configured to discharge a liquid. Thus, the liquid spray is generated by using separate liquid and gas outlets. Accordingly, the atomized liquid spray is at least partially generated outside the nozzle assembly when the gas flow discharged from the fluid outlet impinges on the liquid discharged from the liquid outlet. The ratio of liquid to gas in the atomized liquid spray is important in achieving optimal liquid content in the atomized liquid spray. The ratio of liquid to gas in the atomized liquid spray can be adjusted by controlling the liquid flow from the liquid outlet and / or the gas flow from the fluid outlet. Thus, as discussed above, providing a liquid outlet in the nozzle assembly is advantageous, facilitating control of the discharge of the liquid, and thus, for example, the liquid content, in the atomized liquid spray.

[0037] In some embodiments, the liquid outlet may be configured to emit the liquid in the form of a liquid stream. Emitting the liquid in the form of a liquid stream results in a high liquid content in the atomized liquid spray. Furthermore, when the liquid is emitted in the form of a liquid stream, this can affect the direction of motion of the generated atomized liquid spray. In other words, by emitting the liquid (and not just the gas) in the form of a stream, the direction of motion of the generated atomized liquid spray can also be fine-tuned (further fine-tuned), i.e., not only utilizing the direction of motion (combined, e.g., aggregate direction of motion) of the gas stream emitted from the fluid outlet, but also utilizing the direction of motion of the liquid emitted from the liquid outlet, thereby not only shaping but also steering the generated atomized liquid spray, thereby facilitating overall control or management over the generated atomized liquid spray.

[0038] In other embodiments, the liquid outlets may be configured to emit liquid in the form of one or more droplets or small droplets that hang from the liquid outlet. Such droplets may be carried away by the gas flow (combined, e.g., aggregated gas flow) in the form of a mist, i.e., an atomized liquid spray, where the spatial distribution of the mist / atomized liquid spray approximately follows the spatial distribution of the gas flow (combined, e.g., aggregated gas flow). Typically, the atomized liquid spray has the approximate shape of a cone extending from the respective fluid outlet to the surface to be cooled. That is, by emitting liquid from the liquid outlets in the form of hanging droplets, the resulting atomized liquid spray is easier to control, since its direction of motion is determined (only) by the direction of motion of the gas flow (combined, e.g., aggregated gas flow) emitted by the fluid outlet.

[0039] In particular, when the liquid outlet is configured to emit liquid at a rate of 0.001 mL / min to 30 mL / min, preferably 0.2 mL / min to 4 mL / min, it is preferable that the liquid be emitted in the form of droplets hanging from the liquid outlet. Additionally, using a liquid flow within the specified range may be advantageous for effective cooling of the tissue surface area due to rapid evaporation of the spray droplets. On the one hand, such a fluid flow allows a sufficient number of droplets to deposit on the tissue surface to exert a cooling effect. On the other hand, when such a liquid flow is used, the number of liquid droplets is not so high that a liquid film is formed. As mentioned above, such a liquid film is undesirable because it effectively reduces the liquid evaporation rate and can cause patient discomfort and undesirable overwetting.

[0040] Additionally or alternatively, the fluid outlet may be configured to emit the liquid at a low pressure in the range of 0.1 bar to 0.5 bar. The low liquid pressure (and correspondingly low liquid droplet velocity) can enhance the effect of the gas flow (combined, e.g., aggregated gas flow) from the fluid outlet in directing the motion of the resulting atomized liquid spray. Additionally, the low liquid pressure helps to avoid dripping of the liquid when the nozzle assembly, or at least the liquid outlet, is turned off.

[0041] In general, the liquid outlet should have an orifice with a diameter of 0.1 mm to 1 mm, preferably 0.3 mm to 0.5 mm. In particular, the above-mentioned pressure ranges and liquid flow rate ranges are compatible with orifices with significantly larger diameters. This avoids the problems that arise when using orifices with small diameters (i.e., on the order of a few micrometers). In particular, small diameter orifices become clogged very quickly, i.e., temporarily by small gas bubbles that are always present in flowing liquids, and over the long term by sediments and impurities in the liquid.

[0042] In some embodiments, the liquid outlet may be configured to release the liquid in a pulsed manner, for example, using a pumping means. Such pulsating operation of the liquid outlet allows for better control of the liquid flow, since the frequency of the pulses can be varied. In some embodiments, the liquid outlet and / or the pumping means may operate at a frequency of 0.1 to 1 kHz, preferably 0.5 to 50 Hz. In particular, to achieve the aforementioned slight liquid flows, positive displacement pumps may be used. A positive displacement pump draws fluid into a compartment at the pump inlet and then moves the fluid to the outlet for discharge. A positive displacement pump moves liquid at the same speed regardless of the pressure applied to the inlet end. Positive displacement pumps can be classified according to the method of moving the liquid: rotary or oscillating (reciprocating). However, as noted, rotary positive displacement pumps are relatively complex. Furthermore, oscillating positive displacement pumps have the advantage that this type of pump necessarily results in pulsating operation. Thus, a oscillating positive displacement pump is a preferred embodiment as a pumping means. Diaphragm pumps are a subclass of oscillating positive displacement pumps, and such diaphragm pumps are an even more preferred embodiment as the pumping means.

[0043] Generally, the liquid may include one or more of the following additives: a solution that enhances evaporation rate, a skin conditioning solution, an aromatherapy solution, and a disinfectant solution. These additives may improve the performance of the nozzle assembly in terms of cooling effect, user experience, and / or safety. Other additives may also be incorporated into the spray to support moisturizing, rapid healing, disinfection, pain relief, or the production of a more pleasant aroma. More generally, any of the above-mentioned substances may be added to the fluid, gas, or both to most effectively combat the undesirable odors that result from, for example, laser ablation of human tissue. In this context, it is again noted that the liquid may be water, but may also be any other suitable liquid, liquid mixture, or solution that is not flammable or harmful to the patient. For example, a water-based solution may be used, provided that the alcohol concentration does not exceed approximately 50%, at which point the solution becomes flammable, especially under laser irradiation. Adding a fast evaporating liquid, such as an alcohol, to the liquid speeds up the evaporation of the droplets of the atomized liquid spray, and therefore increases the cooling rate.

[0044] In some embodiments, the droplet size of the atomized liquid spray produced by the nozzle assembly can range from 5 micrometers to 200 micrometers, preferably from 10 micrometers to 100 micrometers. As noted, the droplets must be small enough to evaporate upon contact with the treated skin, thus avoiding droplet coalescence and the formation of a liquid film on the skin surface. As discussed above, such a liquid film reduces the rate of heat transfer from the skin to the liquid medium. On the other hand, the droplets must be large enough to adhere to the skin surface and allow heat transfer from the epidermis to the cooling medium. It is further noted that the droplet size is affected by the size of the liquid outlet orifice.

[0045] In some embodiments, the nozzle assembly includes at least one liquid outlet in combination with a plurality of fluid outlets configured to emit gas that impinges on liquid emitted from the liquid outlet to produce an atomized liquid spray. For example, the liquid outlets may be positioned between a first fluid outlet and a second fluid outlet, preferably on a straight line extending from the first fluid outlet to the second fluid outlet. More generally, the plurality of fluid outlets may surround the (at least one) liquid outlet, for example, symmetrically or asymmetrically.

[0046] By using a nozzle assembly including multiple fluid outlets (configured to emit gas) adjacent to a single liquid outlet, the generated atomized liquid spray can be directed to different areas on the tissue surface (without moving the nozzle assembly or the tissue cooling device that may itself employ the nozzle assembly). That is, each fluid outlet may have a different direction for emitting gas. Because the gas flows with the liquid when producing the atomized liquid spray, the different directions in which the fluid outlets point correspond to different areas on the tissue surface to which the spray is applied. Multiple fluid outlets are particularly beneficial when the atomized liquid spray is to cover a relatively large tissue surface (e.g., a large area of ​​skin) because switching between various fluid outlets is generally faster than reorienting a single fluid outlet or the entire nozzle assembly.

[0047] Furthermore, when two or more gas streams (each having a different direction of motion) emitted from the fluid outlets simultaneously strike a liquid, the direction of the resulting atomized liquid spray is approximately parallel to the direction of the combined, e.g., aggregate momentum, of the gas pulses. As a result, it is possible to spray areas that would remain unsprayed if individual gas streams were used. Furthermore, when such a combination, e.g., an aggregate gas stream is used in combination with an individual gas stream (e.g., in a temporal sequence), it is possible to spray a spray onto any area on the tissue surface (e.g., located below the nozzle assembly), thereby changing the shape of the sprayed area to a desired shape. This allows for optimization of cooling efficiency and minimization of cooling power during use, since areas of the skin that are not heated as much can be bypassed during energy delivery.

[0048] In some embodiments, each of the fluid outlets has an associated conveying means. This facilitates independent operation of each fluid outlet, i.e., operation of one fluid outlet does not interfere with or depend on operation of another fluid outlet. Thus, preferably, gas flow from each of the fluid outlets can be controlled independently of gas flow from the other fluid outlets.

[0049] In a second aspect, the present invention relates to a method of cooling a treatment area with a fluid using the nozzle assembly described above. The method includes the steps of independently activating at least one of the first fluid outlet and the second fluid outlet, and simultaneously activating the first fluid outlet and the second fluid outlet. As described in detail above, such simultaneous operation of the first fluid outlet and the second fluid outlet can provide fluid to portions of the treatment area that would not be provided with fluid if the first fluid outlet and the second fluid outlet were activated exclusively and independently. Conversely, operating both the first fluid outlet and the second fluid outlet individually and simultaneously can provide fluid to a large area, for example, in a scan-like manner.

[0050] In particular, such a method and / or fluid nozzle of the present invention can be used to cool a treatment area treated by an energy-based medical device, such as a laser. The method and / or fluid nozzle of the present invention can be suitable for avoiding overheating. For example, the method and / or fluid nozzle of the present invention can keep the temperature of the treatment area below 50°C, preferably below 42°C, more preferably below 37°C, and most preferably below 33°C. In this case, the method and / or fluid nozzle of the present invention can be used to cool a treatment area by using a 5cm 2 ~10000cm 2 , preferably 10 cm 2 ~5000cm 2 , more preferably 25 cm 2 ~4000cm 2 , most preferably 50 cm 2 ~500cm 2 It is possible to cool (essentially evenly cool) a large treatment area of ​​about 100 mm in size.

[0051] To this end, the nozzle assembly may be incorporated into the handpiece of the laser system, for example, as part of a cooling device. In this manner, the fluid used to enable cooling by the nozzle assembly can be easily applied at or near the treatment area irradiated by the laser pulses, where these laser pulses are emitted from the handpiece of the laser system. The same considerations apply to other energy-based medical devices.

[0052] Preferably, a device for emitting a jet of cold air is additionally mounted on the handpiece of the laser system. The cold air emitted from this device can provide an additional cooling effect on the treated tissue (in addition to the cooling provided by the fluid). In particular, as will be explained in more detail below, a synergistic effect is achieved between the cold air cooling and the fluid cooling, since the cooling effect achieved when both the fluid and the cold air are applied (measured as the drop in tissue temperature after cooling) is greater than the sum of the cooling effects of the fluid and the cold air.

[0053] Preferably, the temperature of the cold air is in the range of -40°C to 0°C, more preferably in the range of -35°C to -20°C.

[0054] According to another aspect, the nozzle assembly is mounted to a scanning device of a laser scanner, for example as part of a cooling device. Such laser scanners are often used to treat large areas, for example, human or animal skin.

[0055] Further preferred embodiments are set out in the accompanying dependent claims.

[0056] It should be noted that any combination of features described above as belonging to certain embodiments / aspects of the present invention is also an embodiment of the present invention, provided that such combination of features is feasible, i.e. does not lead to any contradiction.

[0057] Some of the embodiments of the present invention are explained in detail below with the aid of the drawings. [Brief explanation of the drawings]

[0058] [Figure 1] 1 illustrates an apparatus for cooling tissue using a nozzle assembly of the present invention. [Figure 2] FIG. 1 shows a nozzle assembly including one liquid outlet and four fluid outlets configured to emit gas. [Figure 3] FIG. 1 illustrates a laser handpiece having attached thereto a device for cooling tissue using the nozzle assembly of the present invention. [Figure 4] 10 is a schematic diagram illustrating how the treatment area to which the cooling fluid is applied can be varied by varying the distance between the nozzle assembly and the tissue surface. [Figure 5] FIG. 10 shows a comparison of skin surface temperatures measured under laser irradiation for six different cooling methods. [Figure 6]1 is a schematic diagram of a nozzle assembly combining a single liquid outlet and four fluid outlets configured to emit gas. [Figure 7] 7 is a schematic illustration of different portions of the treatment area that can be covered by cooling fluid depending on which fluid outlet of the nozzle assembly of FIG. 6 is activated. DETAILED DESCRIPTION OF THE INVENTION

[0059] 1 shows an apparatus 100 for cooling tissue with a fluid, the apparatus 100 comprising a liquid reservoir 1, a pumping means 2, a gas reservoir 10, a gas compressor 3, a gas valve 9 and a gas pressure regulator. The apparatus 100 further comprises a liquid delivery means 5 and a gas delivery means 6, 6′, which are combined within a nozzle assembly 7.

[0060] Conveying means 5 in the form of a tube delivers liquid from the liquid reservoir 1 to the nozzle assembly 7, the flow of liquid being regulated by pumping means 2. In the embodiment of Figure 1, pumping means 2 is a low pressure pump (e.g. a diaphragm pump) which operates in a pulsed mode at a frequency lying in the range of 0.1 kHz to 1 kHz, preferably 0.5 Hz to 50 Hz.

[0061] The gas conveying means 6, 6' are in the form of pipes that convey gas from a gas reservoir 10 to the nozzle assembly 7 via a gas compressor 3, which is used to regulate the gas pressure. In the device of Figure 1, the gas pressure is in the range of 1 bar to 10 bar.

[0062] As noted, FIG. 1 illustrates multiple gas valves 9, which correspond to multiple fluid outlets 11 in the nozzle assembly 7, each configured to emit gas. In this manner, by opening and closing the various gas valves 9, it is possible to control which of one or more fluid outlets emits gas at any given time. Furthermore, by controlling the gas valves 9 and thereby actuating / operating particular fluid outlets 11, it is possible to determine the direction of movement of the fluid for cooling the treatment area, particularly the atomized liquid spray (hereinafter simply referred to as "spray") produced by / emitted from the nozzle assembly 7. Additionally, by using the gas valves 9 to change the pattern, length, and momentum of the gas streams emitted from each of the fluid outlets 11, it is possible to achieve a desired shape of the spray area.

[0063] 1, the pumping means 2, the gas compressor 3, and the gas valve 9 are connected to the spray controller 4. Thus, the spray controller 4 can control the amount of liquid and gas sent to the nozzle assembly 7, as well as the delivery pressure of the liquid and gas. Accordingly, the spray controller 4 also determines which of the fluid outlets 11 are activated. In particular, the spray controller can operate each of the fluid outlets 11 independently. However, the spray controller can also operate two or more fluid outlets 11 simultaneously.

[0064] The spray controller 4 is itself connected to a computer control means 12 of the energy utilization device (not shown), thereby enabling synchronization of the pulsed spray operation with the pulses of the energy utilization device. In some embodiments, the computer control means 12 can perform at least some (e.g., one or more) of the functions of the spray controller 4. Conversely, in some embodiments, the spray controller 4 can perform at least some (e.g., one or more) of the functions of the computer control means 12. In some embodiments, the spray controller 4 and the computer control means 12 may be the same entity, i.e., only a spray controller, e.g., the spray controller 4, or a computer control means, e.g., the computer control means 12, may be provided.

[0065] It is further noted that the amount of liquid in the spray, the liquid / gas ratio and / or the droplet size are important factors in achieving optimal evaporative cooling of the epidermal surface. In this case, the amount of liquid in the spray can be adjusted, for example, by pulsing the pumping means 2 or by adjusting the pressure in the liquid reservoir 1. In particular, a pumping frequency of 1 Hz to 20 Hz has been used to achieve an optimal liquid content in the spray, with a liquid flow rate of 0.001 to 30 mL / min, preferably 0.2 to 4 mL / min.

[0066] The gas / liquid ratio is preferably adjusted by a combination of adjusting the pumping means 2 and the gas pressure from the gas reservoir 10. The gas pressure to achieve a suitable gas / liquid ratio for the spray is in the range of 0.1 to 20 bar, preferably 1 to 10 bar. The corresponding liquid flow density for the spray is 0.001 mL / (min×cm 2 ) to 2mL / (min × cm 2 ), preferably in the range of 0.002 mL / (min × cm 2 ) to 0.5mL / (min × cm 2) which, on the one hand, results in a sufficient number of sufficiently small droplets deposited on the surface area to be cooled, and, on the other hand, the number of droplets is not so large that the formation of a liquid film is thus avoided (which effectively reduces the liquid evaporation rate and causes unpleasant and undesirable excessive wetting of the patient, the bed and the surrounding environment).

[0067] As mentioned above, typical liquid flow rates for achieving typical treatment areas and cooling times range from 0.001 mL / min to 30 mL / min. These are extremely low liquid flow rates that present significant technical challenges to reliably achieve. In particular, positive displacement pumps are used in cooling systems, as shown in FIG. 1. Positive displacement pumps draw fluid into a compartment at the pump's inlet and then expel it to an outlet, where the fluid has the same velocity regardless of the pressure at the inlet. Such positive displacement pumps are sometimes classified according to the method used to move the liquid: rotary or oscillating (reciprocating). However, rotary positive displacement pumps are relatively complex. Furthermore, oscillating positive displacement pumps have the advantage that this type of pump necessarily involves pulsating operation. Thus, oscillating positive displacement pumps, particularly diaphragm pumps, are used as pumping means 2 in cooling systems according to FIG. 1. By pulsating these low-pressure pumps, the liquid flow rate level can be precisely adjusted.

[0068] Due to the low liquid flow rate and low liquid pressure, it is advisable to use a relatively large office for the liquid outlet 8 of the nozzle assembly 7. In particular, the diameter of the office should be in the range of 0.1 mm to 1.0 mm.

[0069] Figure 2 shows a nozzle assembly 7 that includes one liquid outlet 8 and four fluid outlets 11 (two of which are shown in slice view), all configured to emit gas. The liquid and fluid outlets are arranged to direct the resulting spray cloud / mist toward different portions of the treatment area, as will be described in more detail below with reference to Figures 6 and 7. When using the nozzle assembly of Figure 2, the liquid flow from liquid outlet 8 and the gas flow from one or more of the fluid outlets 11 are mixed externally, thereby producing an atomized liquid spray.

[0070] FIG. 3 shows a laser handpiece equipped with a tissue cooling device using the nozzle assembly of the present invention (labeled "spray nozzle" in this figure). As noted, a corresponding laser system includes a laser system body, a laser delivery means (e.g., an articulating arm or optical fiber), and a handpiece (shown in FIG. 3), which is coupled to the distal end of the laser delivery means. The optical characteristics and configuration of the handpiece determine the shape and size of the laser irradiation area. Both the pumping means and the gas pressure regulator / gas compressor of the tissue cooling device are coupled to the computer control means of the laser system. In this manner, synchronization of the pulsed spray operation and the emitted laser pulses is possible.

[0071] As can be seen in Figure 3, the spray is emitted from the nozzle assembly, and the cross section of the emitted spray gradually widens until the spray jet has the shape of a cone. As noted, the spray is directed toward a treatment area on the tissue surface; i.e., the area on the tissue surface to which the spray is directed essentially corresponds to the spot size of the laser beam emitted from the handpiece. Thus, when the spray and the laser pulse are synchronized, cooling of the tissue by the spray can occur simultaneously with laser treatment of the tissue.

[0072] The cone angle of the generated spray may be, for example, up to 20° (see FIG. 3). The cone angle and the distance between the nozzle assembly and the treatment area define the surface area impinged by the spray pulses (which is simultaneously cooled by the spray). For example, if the distance H from the gas nozzle to the surface to be cooled is H=20 cm, then the diameter D1 of the cooled area is equal to D1≈7 cm. In some embodiments, the cooled area is cooled evenly across the entire diameter D1. In other examples, the cooled area is cooled evenly across only a portion of the diameter D1, for example across the diameter D0. In some embodiments, the diameter D0, corresponding to the relatively evenly cooled central portion, is D0≈3 cm.

[0073] The size of the sprayed area can be adjusted to match the size of the treatment area by adjusting the height H, as shown in FIG. 4. In particular, FIG. 4 shows that the area on the tissue surface that is sprayed increases when the height H1 is increased to H2. More generally, the sprayed area can also be changed by changing the height and / or angle of the nozzle assembly (labeled "spray nozzle" in FIG. 4) relative to the tissue. Naturally, this form of adjustment of the sprayed area requires movement of the nozzle assembly (together with a device for cooling the tissue), which is generally cumbersome, impractical, and slow. Therefore, this adjustment can be effectively used only for coarse adjustment / change of the sprayed area (if at all); i.e., generally speaking, the distance between the treatment area and the nozzle assembly is not arbitrarily selectable (e.g., to adjust which section / portion of the treatment area should be cooled), especially when used in conjunction with an energy-based (medical) device such as those just mentioned. Instead, the distance between the treatment area and the nozzle assembly may be limited by, for example, the working distance required by the energy-utilizing (medical) device. Therefore, it is important to note that some or even all of the advantages of the present invention described herein cannot be obtained simply by varying the distance between the treatment area and the nozzle assembly. Rather, the present invention generally requires a specific placement (e.g., including a specific orientation) of the fluid outlet to achieve the desired effects described herein. It should be understood that, as used herein, the above-described placement (e.g., orientation) of the fluid outlet may depend on the distance between the treatment area and the nozzle assembly, which may depend on the working distance of the energy-utilizing (medical) device in association with which the nozzle assembly is used.

[0074] In some embodiments of the present invention, the height H of the nozzle assembly above the treatment area is controlled by a spacer of a certain length, which may be attached to the laser handpiece and may be changed by actuating a mechanism. As can be seen in FIG. 4, a spacer of a certain length contacts the skin surface (within the perimeter of the treatment area) and therefore maintains a constant distance between the nozzle and the tissue surface (i.e., the value H remains constant). Within the two sections of FIG. 4, the length of the spacer increases from H1 to H2, thereby increasing the height of the nozzle above the treatment area. In yet another embodiment of the present invention, the angle of the nozzle assembly relative to the tissue may be adjusted by adjusting a joint element between the nozzle assembly and the body of the laser handpiece.

[0075] 3 also shows a unit that emits a stream of cold air, which is also attached to the laser handpiece. The stream of cold air is directed toward the treatment area, thus having a cooling effect on the treatment area (in addition to the atomized liquid spray from the nozzle assembly). Note that in FIG. 3, a spacer is attached to the cold air unit.

[0076] To quantify this additional cooling effect, Figure 5 shows a comparison of the skin surface temperatures measured under laser irradiation, displaying the effects of different cooling methods as follows: Line a: no cooling, Line b: forced cold air cooling using a commercial Cryo 6 device (manufactured by Zimmer); Line c: Cooling by micro-pulse spray as described above, Line d: cooling by micropulse spray as described above in combination with forced air cooling (room temperature air), and · Lines e, f: Cooling by the micropulse spray described above combined with forced air cooling (cold air from the Cryo 6 device) for two different levels of cold air flow.

[0077] As can be seen from Figure 5, the cooling by the micro-pulse spray described above is significantly faster (see line c) than the commonly used forced cold air cooling (see line b). The inventors have also discovered that the cooling rate of the micro-pulse spray cooling can be further increased by directing an additional forced cold air stream toward the treatment area (see lines e and f). On the other hand, an additional forced air stream at room temperature does not significantly contribute to the cooling rate (see line d).

[0078] In some cases, a large area of ​​tissue must be irradiated, for example, during a hair removal procedure, and a handpiece with a large spot size of the laser beam or scanning device is used. In this case, the spray application area may be very narrow, especially if uniform cooling is desired, but only a portion of the area to be cooled is uniformly cooled. For example, the diameter D1 of the area to be cooled may be equal to D1≈7 cm, which is already smaller than the diameter of the laser spot. Meanwhile, the diameter D0 corresponding to the central portion that is relatively uniformly cooled is only D0≈3 cm, which exacerbates the problem. In other cases, it may be desirable to move the laser beam along the treatment area to achieve more cooling, i.e., to cool the tissue area before irradiation. Similarly, it may be advantageous to post-cool the irradiated treatment area. Alternatively, it may be advantageous to allow the treated tissue to be pre-cooled, cooled, or post-cooled while moving the laser beam over the entire treatment area.

[0079] In such cases, the "scanning micropulse spray device" of the present invention can be used, where at least one liquid outlet is combined with multiple fluid outlets, each configured to emit gas and directed, if applicable, to different areas or portions of the tissue / treatment area. By operating the multiple fluid outlets individually and simultaneously, it is possible to achieve relatively uniform spray coverage of large, arbitrarily shaped skin areas.

[0080] FIG. 6 is a schematic diagram of a nozzle assembly in which a single liquid outlet is symmetrically surrounded by four fluid outlets, all configured to emit gas and conceptually positioned at the corners of a rectangle. For purposes of this disclosure, the nozzle assembly of FIG. 6 may be similar to or even identical to the nozzle assembly 7 shown in FIG. 1 and, in particular, FIG. 2. In this embodiment, the liquid outlet is connected to a liquid input W, and the fluid outlets are connected to corresponding gas inputs A1, A2, A3, and A4. A single pressurized gas source is provided, and this pressurized gas source is connected to the gas inputs A1, A2, A3, and A4 by four separate gas valves. However, it is equally possible for each fluid outlet to be connected to a separate pressurized gas source, or for some fluid outlets to share a pressurized gas source, each fluid outlet may be connected to its own corresponding pressurized gas source. By opening or closing these gas valves, the area cooled by the spray can be varied. For example, if the laser scanner is adjusted to scan the laser beam only over regions S4 and S2 (shown in FIG. 6), the gas valve may be controlled in such a way that the spray is directed only to regions S4 and S2. In another embodiment, the laser scanner may be synchronized in such a way that the cooled region primarily tracks the currently irradiated region. Thus, if the scanned laser beam advances from, for example, S1 to S4 during scanning, so too will the scanned micro-pulse spray.

[0081] In particular, the nozzle assembly of Figure 6 includes fluid outlets that can operate individually and simultaneously and are spaced apart from one another so that the atomized liquid spray they produce (or, alternatively, contribute to) covers not only the portions S1-S4 shown in Figure 6 but also other portions not included within S1-S4 (in any combination thereof), as will be described in more detail below. Specifically, as can be inferred from Figure 6, the fluid outlets are each configured to emit gas in different directions of motion, which intersect at a point on a line extending perpendicularly from the liquid outlet of the nozzle assembly to the treatment area. In this case, the liquid outlet is centrally located in the nozzle assembly, symmetrically surrounded by the four fluid outlets. In other words, the fluid outlets are thus arranged in an X-shape relative to each other with respect to respective portions of the treatment area. That is, the distance between the center of portion S1 and the first fluid outlet is greater than the distance between the center of portion S1 and the second fluid outlet, which is greater than the distance between the center of portion S2 and the second fluid outlet, and so on. Notably, the above-described lines extending from the liquid outlets to the treatment area are parallel to the direction of motion of the liquid stream that the liquid outlet is configured to emit (however, the same considerations apply mutatis mutandis if the liquid outlet is configured to emit liquid, for example, in the form of droplets hanging from the liquid outlet). Thus, the gas stream emitted from any of the fluid outlets impinges on the liquid stream and, carrying the liquid stream therewith, produces an atomized liquid spray that then covers a corresponding portion of the treatment area, assuming individual operation of each fluid outlet.

[0082] However, it is also possible to operate two or more fluid outlets simultaneously. Because the directions of movement of the respective gas streams intersect with each other, i.e., the fluid outlets are arranged in an X-shape relative to one another, the gas streams collide at a distance from the treatment area. The gas streams are then diverted from one another so that the atomized liquid spray produced using the gas streams covers portions of the treatment area not included in portions S1-S4 (or in any combination thereof), as will be described in more detail below with reference to FIG. 7.

[0083] In the embodiment of FIG. 6, the gas streams impinge at approximately one-quarter of the total distance between the nozzle assembly and the treatment area, closer to the nozzle assembly than the treatment area. However, this may be different in other embodiments. In general, two or more gas streams each emitted from a gas outlet can impinge at any distance from the treatment area and / or the nozzle assembly. For example, the gas streams may impinge at one-quarter, one-third, or one-half of the distance between the nozzle assembly and the treatment area, as viewed from either the nozzle assembly or the treatment area. When more than two gas streams impinge, there may also be multiple impingement points at various distances from the nozzle assembly and / or the treatment area.

[0084] In some embodiments, operation may alternate between individual or multiple ones of the valves in a manner such that pre-cooling, post-cooling, or both, is performed on the tissue being treated, for example, as the laser beam is moved across the target region. Typically, pre-cooling and / or post-cooling occurs at a different time compared to the cooling of the treatment region. Alternatively, a nozzle assembly with multiple fluid outlets, each configured to emit gas, may be operated in a manner such that only pre-cooling, post-cooling, or both, is performed, but no spray is directed onto the currently irradiated region.

[0085] Generally, by opening and closing the gas valves for one or more of the fluid outlets (given appropriate placement, e.g., orientation, of the fluid outlets), it is possible to control the rate at which the spray is applied to an area and to select the section / portion of the tissue surface / treatment area to be cooled, i.e., covered by the fluid (in this case, the atomized liquid spray) for cooling.

[0086] This can be understood based on Figure 7, which is a schematic illustration of different portions of the treatment area that can be covered by the cooling fluid, i.e., spray, depending on which fluid outlet of the nozzle assembly of Figure 6 is activated. That is, when only the first fluid outlet (connected to gas input A1) is activated, portion S1 of the treatment area is covered by spray. When only the second fluid outlet (connected to gas input A2) is activated, portion S2 of the treatment area is covered by spray (see also the right panel of Figure 4). When only the third fluid outlet (connected to gas input A3) is activated, portion S3 of the treatment area is covered by spray. When only the fourth fluid outlet (connected to gas input A4) is activated, portion S4 of the treatment area is covered by spray (see also the left panel of Figure 4). In Figure 7, portions S1-S4 do not completely overlap each other, but in other embodiments, this may be different as described above. In fact, in Fig. 7, there are voids between the portions S1 to S4 that are not covered by any of the sprays, at least as long as only the first to fourth fluid outlets are operated individually. In Fig. 7, the portions S1, S2, S3, and S4 are round, e.g., circular, and similar, e.g., have the same diameters d1 = d2 = d3 = d4. The portions S1, S2, S3, and S4 also have similar, and even partially identical, distances from each other (to reiterate, the distance between two portions can also be defined as the minimum distance between any one point (on the periphery) of one portion and any one point (on the periphery) of the other portion), i.e., TIFF0007738048000004.tif6150, in this case, TIFF0007738048000005.tif6150 and TIFF0007738048000006.tif6150 (notice that this differs from the embodiment of FIG. 4, in which portions S1-S4 each touch their two nearest neighbors).

[0087] However, these voids, ie, portions of the treatment area that are not covered by any spray when only an individual fluid outlet is activated, can be covered with spray by activating two or more fluid outlets simultaneously.

[0088] For example, if the first and second fluid outlets are activated simultaneously, a portion S of the treatment area 12 is covered by the spray, in this case a portion S of the treatment area 12 is located partially between the treatment area portions S1 and S2 (i.e., between the treatment area portions S 12 (The fluid outlets S1 and S2 are not entirely contained within the treatment area portions S1 and S2.) When the second and third fluid outlets are activated simultaneously, the treatment area portions S 23 is covered by the spray, in this case a portion S of the treatment area 23 is located partially between the treatment area portions S2 and S3 (i.e., between the treatment area portions S 23 (The fluid outlets S2 and S3 are not entirely contained within the treatment area portions S2 and S3.) When the third and fourth fluid outlets are activated simultaneously, the treatment area portions S 34 is covered by the spray, in this case a portion S of the treatment area 34 is located partially between the treatment area portions S3 and S4 (i.e., between the treatment area portions S 34 (The fluid outlets S3 and S4 are not entirely contained within the treatment area portions S3 and S4.) When the fourth fluid outlet and the first fluid outlet are activated simultaneously, the treatment area portions S 41 is covered by the spray, in this case a portion S of the treatment area 41 is located partially between the treatment area portions S4 and S1 (i.e., between the treatment area portions S 41(Note that the first and third fluid outlets or the second and fourth fluid outlets may be simultaneously activated, resulting in the treatment area being within the treatment area portions S4 and S1.) 13 or part S 24 (both not shown in FIG. 7) are covered by the spray, in this case a portion S of the treatment area. 13 ,S 24 are located at least partially between the treatment area portions S1 and S3 and between the treatment area portions S2 and S4, respectively (i.e., treatment area portions S 13 is not entirely contained within portion S1 and / or portion S3 of the treatment area and is not entirely contained within portion S 24 is not completely contained within portions S2 and / or S4 of the treatment area). In this case, portions S 12 ,S 23 ,S 34 ,S 41 ,S 13 ,S 24 At most, the parts S partially overlap each other (i.e., they are not fully contained within each other or any combination of each other). 12 ,S 34 have a slightly elliptical, e.g., nearly circular, shape, and the diameter (defined as the maximum distance between any two points on their respective perimeters) is d 12 =d 34 >d1=d2=d3=d4. Part S 23 ,S 41 has a more pronounced elliptical shape and a diameter d 23 =d 41 >d1=d2=d3=d4, but d 23 =d 41 <d 12 =d 34 Diameter d 12 ,d 34 is the diameter d 23 ,d 41 , i.e., the portion S 12 ,S 34 is the part S with respect to these major axes (i.e., the longer axes). 23 ,S 41is oriented perpendicular to .

[0089] Additional portions of the treatment area that may not be covered by spray at all by the individual operation of one or more single fluid outlets or the simultaneous operation of any two fluid outlets can be covered by spray by activating three fluid outlets simultaneously. For example, when the first fluid outlet, the second fluid outlet, and the third fluid outlet are activated simultaneously, a portion S of the treatment area may be covered by spray. 123 (not shown in FIG. 7) can be coated by spraying, in which case the portion S of the treatment area 123 is located at least partially between the treatment area portions S1, S2, and S3 (i.e., between the treatment area portions S 123 (These regions are not entirely contained within the treatment region portions S1, S2 and / or S3). In addition, the treatment region portions S 123 is the portion of the treatment area S 12 ,S 13 ,S 23 and at most partially overlap (i.e., the portion of the treatment area S 123 is the portion of the treatment area S 12 ,S 13 and / or S 23 (The treatment area is not completely contained within the second fluid outlet, the third fluid outlet, and the fourth fluid outlet.) 234 (not shown in FIG. 7) can be coated by spraying, in which case the portion S of the treatment area 234 is located at least partially between the treatment area portions S2, S3, and S4 (i.e., between the treatment area portions S 234 (The treatment area is not entirely contained within portions S2, S3 and / or S4 of the treatment area.) In addition, portions S 234 is the portion of the treatment area S 23 ,S 24 ,S 34 and at most partially overlap (i.e., the portion of the treatment area S 234 is the portion of the treatment area S 23 ,S 24 and / or S 34When the third fluid outlet, the fourth fluid outlet, and the first fluid outlet are activated simultaneously, the portion S of the treatment area 341 (not shown in FIG. 7) can be coated by spraying, in which case the portion S of the treatment area 341 is located at least partially between the treatment area portions S3, S4, and S1 (i.e., between the treatment area portions S 341 (The treatment area is not entirely contained within portions S3, S4 and / or S1 of the treatment area.) In addition, portions S 341 is the portion of the treatment area S 34 ,S 13 ,S 41 and at most partially overlap (i.e., the portion of the treatment area S 341 is the portion of the treatment area S 34 ,S 13 and / or S 41 When the fourth fluid outlet, the first fluid outlet, and the second fluid outlet are activated simultaneously, the portion S of the treatment area 412 (not shown in FIG. 7) can be coated by spraying, in which case the portion S of the treatment area 412 is located at least partially between the treatment area portions S4, S1, and S2 (i.e., between the treatment area portions S 412 (The treatment area is not entirely contained within portions S4, S1 and / or S2 of the treatment area.) In addition, portions S 412 is the portion of the treatment area S 41 ,S 24 ,S 12 and at most partially overlap (i.e., the portion of the treatment area S 412 is the portion of the treatment area S 41 ,S 24 and / or S 12 In this case, S 123 ,S 234 ,S 341 ,S 412 are said to at most partially overlap one another (i.e., the parts are not wholly contained within each other or any combination of each other).

[0090] Yet another portion of the treatment area that cannot be covered by spray at all, whether by the individual operation of one or more single fluid outlets or the simultaneous operation of any two or three fluid outlets, can be covered by spray by activating all four fluid outlets simultaneously. That is, when the first fluid outlet, the second fluid outlet, the third fluid outlet, and the fourth fluid outlet are activated simultaneously, the portion S of the treatment area is covered by spray. 1234 is covered by the spray, in this case the portion of the treatment area S 1234 are located at least partially between the treatment area portions S1, S2, S3, and S4 (i.e., between the treatment area portions S 1234 is not entirely contained within portions S1, S2, S3 and / or S4 of the treatment area. 1234 is the portion of the treatment area S 12 ,S 23 ,S 34 ,S 41 ,S 13 ,S 24 may be at least partially located between each other (i.e., portions S of the treatment area 1234 is the S of the treatment area 12 ,S 23 ,S 34 ,S 41 ,S 13 and / or S 24 (It is not completely contained within the treatment area.) Furthermore, 1234 is the portion of the treatment area S 123 ,S 234 ,S 341 ,S 412 may be at least partially located between each other (i.e., portions S of the treatment area 1234 is the portion of the treatment area S 123 ,S 234 ,S 341 and / or S 412 (It is never completely contained within the part S. 1234 has a round, e.g., circular, shape, and its diameter is d 1234 ≒d1=d2=d3=d4.

[0091] As is apparent from the above, simultaneous operation of additional fluid outlets will generally result in additional sections or portions of the treatment area being covered by the spray, but this does not mean that any and all combinations of fluid outlets must be activated simultaneously to cover a given target treatment area. For example, the entire (nearly entire) rectangular target treatment area T in FIG. 7 can be covered by the spray from portions S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, S23, S24, S25, S26, S27, S28, S29, S30, S31, S32, S33, S34, S35, S36, S37, S38, S39, S40, S41, S42, S43, S44, S45, S46, S47, S48, S49, S50, S51, S52, S53, S54, S55, S56, S57, S58, S59, S60, S61, S62, S63, S64, S65, S66, S67, S68, S69, S70, S71, S72, S73, S74, S75, S76, S77, S78, S79, S80, S81, S82, S83, S84, S85, S86, S87, S88, S89, S90, S91, S92, S93, S94, S95, S96, S97, S98, S99, S109, S109, S109, S1109, S1111, S112, S120 12 ,S 23 ,S 34 ,S 41 ,S 1234 can be spray coated by covering each of the S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, S23, S24, S25, S26, S27, S28, S29, S30, S31, S32 12 ,S 23 ,S 34 ,S 41 ,S 1234 Therefore, the simultaneous operation of each of the fluid outlets causes the spray to be completely (almost completely) contained within the set S (the union of these sets). 13 ,S 14 ,S 123 ,S 234 ,S 341 and / or S 412 It also does not need to be covered.

[0092] As is apparent from the above, the nozzle assembly of the present invention can be used to effectively cover treatment areas of various sizes and any shape with cooling fluid by the individual and / or simultaneous operation of each appropriate fluid outlet (or combination of fluid outlets). For example, while FIG. 7 shows a rectangular target treatment area covered using four fluid outlets, target treatment areas of various shapes can be covered using the same or a different number of fluid outlets. For example, a relatively small rectangular target treatment area can be adequately covered using two fluid outlets, a triangular target treatment area can be covered using three fluid outlets, and a more complex target treatment area can be covered using five or more fluid outlets.

[0093] In particular, the nozzle assembly of the present invention can therefore also be used to scan a target treatment area, for example, in synchronization with a laser beam acting on the target treatment area. In this case, the nozzle assembly can also be used to perform pre-cooling and post-cooling. This will be explained exemplarily based on the target treatment area T and various portions shown in Figure 7. First, the spray can be applied in the following pattern ("pre-pattern"), for example: S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, S23, S24, S25, S26, S27, S28, S29, S30, S31, S32, S33, S34, S35, S36, S37, S38, S40, S41, S42, S43, S44, S45, S46, S47, S48, S49, S50, S51, S52, S53, S54, S55, S56, S57, S58, S59, S60, S61, S62, S63, S64, S65, S66, S67, S68, S69, S70, S71, S72, S73, S74, S75, S76, S77, S78, S79, S80, S81, S82, S83, S84, S85, S86, S87, S88, S89, S90, S91, S92, S93, S94, S95, S96, S97, S98, S99, S109, S109, S110, S11 12 ,S2,S 12 By periodically repeating the coating of these parts according to the formula - as a preliminary form of cooling - parts S1, S2, S 12 After a given time, the spray can then be applied in the following pattern, for example: S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, S23, S24, S25, S26, S27, S28, S29, S30, S31, S32, S33, S34, S35, S36, S37, S38, S39, S40, S41, S42, S43, S44, S45, S46, S47, S48, S49, S50, S51, S52, S53, S54, S55, S56, S57, S58, S59, S60, S61, S 12 ,S2,S 1234 , S 23 ,S3,S 34 ,S4,S1,S 12 ,S2,S 23 ,S3,S 34 ,S4,S 1234 ,S 41 By periodically repeating the coating of these parts according to the above formula - as a form of (main) cooling - parts S1, S2, S3, S4, S 12 ,S 23 ,S 34 ,S 41 ,S 1234 This allows the entire target treatment area T to be covered (or virtually covered).

[0094] In this case, the operation of the cooling mechanism, e.g., the amount of liquid or the gas / liquid ratio, can be adjusted in response to the recorded temperature of the tissue after treatment, which may be recorded using a temperature detector, which may also be incorporated into a thermal camera, which provides an additional visual aid for the laser operator.

[0095] Finally, the devices for cooling tissue using micropulse sprays described herein can be designed as stand-alone units for use with different energy application devices or can be incorporated into a particular energy application device. Furthermore, the cooling device can be operated independently of the energy application device or can be configured to accept certain control signals from the energy application device. In the latter case, the emission of spray pulses from the cooling device can be synchronized (in terms of time and / or treatment area) with the delivery of therapeutic energy, for example. [Explanation of symbols]

[0096] 1 fluid reservoir 2. Pressure feeding means 3 Gas compressor 4 Spray Controller 5. Liquid transport 6,6' Gas conveyance means 7 Nozzle Assembly 10 Gas Reservoir 11 Fluid outlet S1 First Part S2 Second part S3 Fourth Part S4 8th part S 12 Third part S 14 9th part S 23 Sixth Part S 24 Part 10 S 34 Part 11 S 123 Seventh Part S 124 Twelfth Part S 134 13th part S 234 The fourteenth part S 1234 Part 15

Claims

1. A nozzle assembly (7) for cooling a treatment area with a fluid, comprising a first fluid outlet (11) and a second fluid outlet (11) operable independently and simultaneously, said first fluid outlet (11) and second fluid outlet (11) comprising: When only the first fluid outlet (11) is activated, the fluid reaches the first portion (S) of the treatment area. 1 ) and When only the second fluid outlet (11) is activated, the fluid reaches the second part (S) of the treatment area. 2 ) are spaced apart from each other so as to cover the second portion (S 2 ) is the first portion (S 1 ) is not completely contained within When both the first fluid outlet (11) and the second fluid outlet (11) are activated, the fluid enters the third portion (S 12 ) are spaced apart from each other so as to cover the third portion (S 12 ) is the first portion (S 1 ) and / or said second portion (S 2 ) and a nozzle assembly (7) that is not entirely contained within the nozzle assembly (7).

2. The first portion (S 1 The center distance between the first portion (S 1 ) and the second fluid outlet (11), and / or The second portion (S 2 The center distance between the second portion (S 2 2. The nozzle assembly (7) of claim 1, wherein the distance between the center of the nozzle (12) is greater than the center of the nozzle (12) and the first fluid outlet (11).

3. The first fluid outlet (11) and the second fluid outlet (11) are arranged such that when both the first fluid outlet (11) and the second fluid outlet (11) are activated, the fluid discharged from the first fluid outlet (11) collides with the fluid discharged from the second fluid outlet (11) at a distance from the treatment area, and the fluid discharged from the first fluid outlet (11) and the fluid discharged from the second fluid outlet (11) are combined to form the third portion (S 12 3. A nozzle assembly (7) according to claim 1 or 2, adapted to form a fluid covering the nozzle.

4. The nozzle assembly (7) of claim 1, wherein the fluid is an atomized liquid spray.

5. The nozzle assembly (7) of claim 4, wherein at least one of the first fluid outlet (11) and the second fluid outlet (11) is configured to emit the atomized liquid spray.

6. 5. The nozzle assembly (7) of claim 4, wherein at least one of the first fluid outlet (11) and the second fluid outlet (11) is configured to emit a gas such that the gas impinges on a liquid to create the atomized liquid spray.

7. 7. The nozzle assembly (7) of claim 6, wherein at least one of the first fluid outlet (11) and the second fluid outlet (11) is configured to emit the gas in pulses, preferably with a pulse duration of 10 ms to 5000 ms, more preferably with a pulse duration of 100 ms to 2000 ms, and / or at a pressure of 0.1 bar to 20 bar, preferably 1 bar to 10 bar.

8. A nozzle assembly (7) according to claim 6, comprising a liquid outlet (8) configured to discharge said liquid.

9. The nozzle assembly (7) of claim 8, wherein the liquid outlet (8) is configured to emit the liquid in the form of a liquid stream.

10. A nozzle assembly (7) according to claim 8, wherein the liquid outlet (8) is configured to emit the liquid in the form of droplets that hang from the liquid outlet.

11. 11. The nozzle assembly (7) of claim 10, wherein the liquid outlet (8) is configured to emit the liquid at a rate of between 0.001 mL / min and 30 mL / min, preferably between 0.2 mL / min and 4 mL / min.

12. 9. The nozzle assembly (7) of claim 8, wherein the liquid outlet (8) is located between the first fluid outlet (11) and the second fluid outlet (11).

13. The fluid outlet (11) may further comprise a third fluid outlet (11) which may function independently and simultaneously with the first fluid outlet (11) and / or the second fluid outlet (11), the third fluid outlet (11) comprising: When only the third fluid outlet (11) is activated, the fluid reaches a fourth portion (S 3 ) and is spaced apart from the first fluid outlet (11) and the second fluid outlet (11) so as to cover the fourth portion (S 3 ) is the first portion (S 1 ) and / or said second portion (S 2 ) is not completely contained within When only the first fluid outlet (11) and the third fluid outlet (11) are activated, the fluid reaches the fifth portion (S) of the treatment area. 13 ) and is spaced apart from the first fluid outlet (11) and the second fluid outlet (11) so as to cover the fifth portion (S 13 ) is the first portion (S 1 ) and / or the fourth portion (S 3 ) is not completely contained within When only the second fluid outlet (11) and the third fluid outlet (11) are activated, the fluid reaches the sixth portion (S 23 ) and is spaced apart from the first fluid outlet (11) and the second fluid outlet (11) so as to cover the sixth portion (S 23 ) is the second portion (S 2 ) and / or the fourth portion (S 3 ) is not completely contained within When only the first fluid outlet (11), the second fluid outlet (11) and the third fluid outlet (11) are activated, the fluid reaches the seventh portion (S 123 ) and is spaced apart from the first fluid outlet (11) and the second fluid outlet (11) so as to cover the seventh portion (S 123 ) is the first portion (S 1 ) and / or said second portion (S 2 ) and / or the fourth portion (S 3 2. The nozzle assembly (7) of claim 1, wherein the nozzle assembly (7) is not entirely contained within the nozzle assembly (7).

14. The fluid outlet (11) may further comprise a fourth fluid outlet (11) which may function independently and simultaneously with the first fluid outlet (11) and / or the second fluid outlet (11) and / or the third fluid outlet (11), wherein the fourth fluid outlet (11) comprises: When only the fourth fluid outlet (11) is activated, the fluid reaches the eighth portion (S 4 ) and is spaced apart from the first fluid outlet (11), the second fluid outlet (11) and the third fluid outlet (11) so as to cover the eighth portion (S 4 ) is the first portion (S 1 ) and / or said second portion (S 2 ) and / or the fourth portion (S 3 ) is not completely contained within When only the first fluid outlet (11) and the fourth fluid outlet (11) are activated, the fluid reaches the ninth portion (S 14 ) and is spaced apart from the first fluid outlet (11), the second fluid outlet (11) and the third fluid outlet (11) so as to cover the ninth portion (S 14 ) is the first portion (S 1 ) and / or the eighth portion (S 4 ) is not completely contained within When only the second fluid outlet (11) and the fourth fluid outlet (11) are activated, the fluid reaches a tenth portion (S 24 ) and is spaced apart from the first fluid outlet (11), the second fluid outlet (11) and the third fluid outlet (11) so as to cover the tenth portion (S 24 ) is the second portion (S 2 ) and / or the eighth portion (S 4 ) is not completely contained within When only the third fluid outlet (11) and the fourth fluid outlet (11) are activated, the fluid reaches an eleventh portion (S) of the treatment area. 34 ) and is spaced apart from the first fluid outlet (11), the second fluid outlet (11) and the third fluid outlet (11) so as to cover the eleventh portion (S 34 ) is the fourth portion (S 3 ) and / or the eighth portion (S 4 ) is not completely contained within When only the first fluid outlet (11), the second fluid outlet (11) and the fourth fluid outlet (11) are activated, the fluid reaches the twelfth portion (S) of the treatment area. 124 ) and is spaced apart from the first fluid outlet (11), the second fluid outlet (11) and the third fluid outlet (11) so as to cover the twelfth portion (S 124 ) is the first portion (S 1 ) and / or said second portion (S 2 ) and / or the eighth portion (S 4 ) is not completely contained within When only the first fluid outlet (11), the third fluid outlet (11) and the fourth fluid outlet (11) are activated, the fluid reaches a thirteenth portion (S) of the treatment area. 134 ) and is spaced apart from the first fluid outlet (11), the second fluid outlet (11) and the third fluid outlet (11) so as to cover the thirteenth portion (S 134 ) is the first portion (S 1 ) and / or the fourth portion (S 3 ) and / or the eighth portion (S 4 ) is not completely contained within When only the second fluid outlet (11), the third fluid outlet (11) and the fourth fluid outlet (11) are activated, the fluid reaches a fourteenth portion (S 234 ) and is spaced apart from the first fluid outlet (11), the second fluid outlet (11) and the third fluid outlet (11) so as to cover the fourteenth portion (S 234 ) is the second portion (S 2 ) and / or the fourth portion (S 3 ) and / or the eighth portion (S 4 ) is not completely contained within When only the first fluid outlet (11), the second fluid outlet (11), the third fluid outlet (11) and the fourth fluid outlet (11) are activated, the fluid reaches a fifteenth portion (S) of the treatment area. 1234 ) and is spaced apart from the first fluid outlet (11), the second fluid outlet (11) and the third fluid outlet (11) so as to cover the fifteenth portion (S 1234 ) is the first portion (S 1 ) and / or said second portion (S 2 ) and / or the fourth portion (S 3 ) and / or the eighth portion (S 4 14. The nozzle assembly (7) of claim 13, wherein the nozzle assembly (7) is not entirely contained within the nozzle assembly (7).

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