Feedback detection for therapeutic devices

Abstract

According to some embodiments, a system for fractionated treatment of tissue includes an electromagnetic radiation (EMR) source configured to generate an EMR beam having a transverse annular energy distribution; an optic configured to converge the EMR beam to a focal region located within tissue; and a window assembly at a lower beam of the optics, the window assembly configured to cool the tissue when placed in contact with an outer surface of the tissue.

Description

[0001] Cross Reference to Related Applications

[0002] This application is a continuation-in-part of International Application No. PCT / US2020 / 059842, International Filing Date, November 10, 2020, entered into the National Stage in the BACKGROUND

[0003] Currently, many energy-based devices are available for fractional treatment of the dermis. These methods include ablative lasers, non-ablative lasers, microneedles, and radiofrequency energy treatment. Generally, these currently available energy-based fractional treatments require damage to the outside (e.g., epidermis) of the skin being treated. In most cases, damage to the epidermis results in the skin appearing inflamed, flawed, or unhealthy immediately after treatment. In addition, severe damage to the epidermis results in one or more infections and requires additional medication. This undesirable appearance results in a downtime after treatment that lasts until the epidermis heals, which can take anywhere from a few days to a few weeks depending on the treatment parameters used (e.g., ablative vs. non-ablative). Most patients do not resume normal activities until after the downtime after treatment. Therefore, it is desirable to have an available fractional treatment system and method that can successfully affect the dermis while minimizing damage to the epidermis so as to minimize the downtime after treatment. SUMMARY

[0004] Skin rejuvenation is generally performed by fractional treatment. Energy-based fractional or fractional treatment refers to treatment where only a portion of the tissue area is exposed to energy. For example, a fractional skin treatment can treat 25% of the skin area with a laser beam, leaving the remaining 75% of the skin in the area untreated. Energy-based skin rejuvenation involves creating controlled small lesions within the collagen network. This small lesion results in a wound healing process during which new collagen is formed. The newly formed collagen tightens the skin, making the skin appear younger. Many skin rejuvenation fractional treatment systems work by using water as a chromophore to achieve photothermolysis.

[0005] Fractional treatment can generally be divided into two categories: ablative and non-ablative. Ablative treatment results in removal of tissue and microdamage to the surface in addition to creating thermal lesions in the dermis. Non-ablative treatment generally does not result in tissue removal but only thermal destruction. The advantage of non-ablative fractional treatment over ablative fractional treatment is a reduction in downtime.

[0006] Energy-based fractional treatments of tissue generally require delivery of a large amount of energy to a selective portion of the tissue and its absorption to achieve the desired destruction or damage. This destruction or damage is repeated over an area of the tissue such that small regions of damaged tissue (e.g., 0.1 mm to 10 mm in diameter) are interwoven with undamaged tissue. Then, during the healing period after treatment, the small regions of damaged tissue are replaced with new tissue. Causing damage within the dermal layer of the skin while minimizing damage to the overlying epidermal layer presents a number of technical challenges, some of which are listed below.

[0007] First, there is no known chromophore within the dermal layer of tissue that is not present within the epidermal layer of tissue. This means that radiation selected to be absorbed within the dermis will also be absorbed within the epidermis.

[0008] Second, because the EMR will be absorbed equally well by the epidermal and dermal layers of the skin, a greater energy density must be delivered to the dermal layer than to the epidermis. To accomplish this, the EMR distribution must be changed such that the focal region (i.e., the region of maximum energy density) of the EMR beam is within the dermis and only the non-focal region (i.e., the region of minimum energy density) of the EMR beam is directed at the epidermal layer of the skin.

[0009] Third, the skin tissue is a turbid medium, which means that radiation propagating through the skin is scattered. The scattering of radiation within the skin tissue makes it more difficult to form a focal region (a region of maximum energy density) at any depth within the tissue, thereby exacerbating the first and second challenges described above.

[0010] Fourth, the focal region (or region of maximum energy density) must be accurately positioned at a depth within the dermal layer of the skin. This ensures that the region of maximum energy density is within the dermis and not within the epidermis to prevent unnecessary damage to the epidermis.

[0011] Fifth, the EMR beam is delivered from outside the tissue; therefore, the epidermis experiences some minimal radiation and small thermal heating (i.e., less than the dermis). To address this fifth challenge, the epidermal layer directly overlying the dermal layer being treated must be actively cooled to prevent thermal damage to the epidermis.

[0012] Accordingly, to provide fractional treatment destruction of the dermal layer of skin tissue while minimizing damage to the overlying epidermal layer, a fractional treatment system and method are needed that address all of the above challenges.

[0013] According to some embodiments, a system for fractionating treatment of tissue includes an electromagnetic radiation (EMR) source configured to generate an EMR beam having a lateral annular energy distribution; optics configured to focus the EMR beam to a focal region located within the tissue; and a window assembly located down-beam of the optics, the window assembly configured to cool the tissue when placed in contact with an external surface of the tissue. The window assembly includes a first window; a second window separate from the first window; and a coolant chamber located between the first window and the second window, wherein the coolant chamber is configured to contain a coolant that does not substantially absorb the EMR beam.

[0014] In some embodiments of the system, the EMR beam has a wavelength in a range between about 1000 nm and 4000 nm.

[0015] In some embodiments of the system, the coolant includes at least one of a dielectric fluid, a fluorocarbon-based fluid, water, an antifreeze, ethylene glycol, and propylene glycol.

[0016] In some embodiments of the system, the optics are additionally configured to focus the EMR beam at a numerical aperture (NA) of at least about 0.2.

[0017] In some embodiments of the system, the system further includes an optically clear medium located between the window assembly and the tissue. In some cases, the optically clear medium includes at least one of glycerol, polyethylene glycol, and phosphate buffered saline.

[0018] In some embodiments of the system, the EMR source includes a beam shaper configured to shape the lateral annular energy distribution. In some versions of the system, the beam shaper includes an axicon.

[0019] In some embodiments of the system, the system additionally includes a controller. In some cases, the controller is configured to control the EMR source to ensure that the window assembly cools the tissue to a determined temperature prior to generation of the EMR beam. In some cases, the controller is configured to control the EMR source to ensure that the window assembly cools the tissue for a determined time prior to generation of the EMR beam.

[0020] According to some embodiments, a method for fractionating treatment of tissue includes cooling the tissue using a window assembly that contacts an external surface of the tissue; generating an electromagnetic radiation (EMR) beam having a lateral annular energy distribution using an EMR source; and focusing the EMR beam to a focal region located within the tissue using optics. In some cases, the window assembly includes a first window; a second window separate from the first window; and a coolant chamber located between the first window and the second window, wherein the coolant chamber is configured to contain a coolant that does not substantially absorb the EMR beam.

[0021] In some embodiments of the method, the EMR beam has a wavelength in a range between about 1000 nm and 4000 nm.

[0022] In some embodiments of the method, the coolant includes at least one of a dielectric fluid, a fluorocarbon-based fluid, water, ethylene glycol, and propylene glycol.

[0023] In some embodiments of the method, converging the EMR beam is performed at a numerical aperture (NA) of at least about 0.2.

[0024] In some embodiments of the method, the method additionally includes introducing an optical tissue-clearing medium between the window assembly and the tissue. In some cases, the optical tissue-clearing medium includes at least one of glycerol, polyethylene glycol, and phosphate buffered saline.

[0025] In some embodiments of the method, the EMR source additionally includes a beam shaper configured to shape the transverse annular energy distribution. In some versions of the method, the beam shaper includes an axicon.

[0026] In some embodiments of the method, the method additionally includes using a controller to control the EMR source to ensure that the window assembly cools the tissue to a determined temperature prior to generating the EMR beam.

[0027] In some embodiments of the method, the method additionally includes using a controller to control the EMR source to ensure that the window assembly cools the tissue for a determined time prior to generating the EMR beam.

[0028] According to some embodiments, a system for fractionating a tissue includes: an electromagnetic radiation (EMR) source configured to generate an EMR beam having a wavelength in a range between about 1400 nm and 3400 nm; a beam shaper configured to shape the EMR beam into a transverse annular energy distribution, wherein the beam shaper includes an axicon; optics configured to converge the EMR beam to a focal region located within the tissue at a numerical aperture (NA) of at least about 0.2; a window assembly located down-beam from the optics, the window assembly configured to cool the tissue when placed in contact with an external surface of the tissue, wherein the window assembly includes: a first window; a second window separated from the first window; and a coolant chamber located between the first window and the second window, wherein the coolant chamber is configured to hold a coolant that does not substantially absorb the EMR beam and includes a fluorocarbon-based fluid; and a controller configured to control the EMR source to ensure that the window assembly cools the tissue to at least one of a predetermined temperature and for a determined time prior to generating the EMR beam.

[0029] According to some embodiments, a system for fractionating tissue includes: an electromagnetic radiation (EMR) source configured to generate an EMR beam having a wavelength; a collimator configured to collimate the EMR beam to a width; a beam shaper including a first axicon and a second axicon, the beam shaper configured to shape the collimated EMR beam to a lateral annular energy profile, wherein the first axicon and the second axicon are separated by a distance along an optical axis, the distance selected to achieve a desired inner diameter of the lateral annular energy profile, and the width of the collimated EMR beam selected to achieve a desired thickness of the lateral energy profile; and optics configured to focus the EMR beam to a focal region within the tissue, thereby affecting the tissue within the focal region.

[0030] According to some embodiments, a system includes: an EMR source configured to generate an EMR beam having a lateral annular energy profile and a wavelength in a range of about 1200 nm to about 12000 nm; optics configured to focus the EMR beam to a focal region located within a tissue; a beam scanning system configured to scan the focal region within the tissue; a window assembly located down-beam of the optics, the window assembly configured to transmit the EMR beam and cool the tissue when placed in contact with an external surface of the tissue, wherein the window assembly includes: a first window; a second window separated from the first window; and a coolant chamber located between the first window and the second window, wherein the coolant chamber is configured to contain a coolant, the coolant including a fluorocarbon-based fluid that does not substantially absorb the EMR beam; and a controller configured to control the EMR source to generate the EMR beam having a plurality of pulses, wherein at least one pulse of the plurality of pulses has a pulse duration of no less than about 100 microseconds.

[0031] In some embodiments of the system, at least one pulse of the plurality of pulses has a pulse energy of no more than about 100 mJ.

[0032] In some embodiments of the system, the system additionally includes a chiller configured to cool the coolant to a temperature in a range of about -20 °C to about 20 °C.

[0033] In some embodiments of the system, the optics are further configured to focus the EMR beam at a numerical aperture (NA) of at least about 0.2.

[0034] In some embodiments of the system, the system additionally includes an optical tissue-clearing medium located between the window assembly and the tissue, wherein the optical tissue-clearing medium includes at least one of glycerol, polyethylene glycol, and phosphate buffered saline.

[0035] In some embodiments of the system, the EMR source additionally comprises a beam shaper configured to shape the transverse annular energy distribution. In some versions of the system, the beam shaper comprises an axicon.

[0036] In some embodiments of the system, the controller is configured to control the EMR source to ensure that the window assembly cools the tissue to a predetermined temperature prior to generating the EMR beam.

[0037] In some embodiments of the system, the controller is configured to control the EMR source to ensure that the window assembly cools the tissue for a predetermined period of time prior to generating the EMR beam.

[0038] In some embodiments of the system, at least one of the EMR source, the optics, and the beam scanning system is configured to control one or more parameters of the EMR beam, including one or more of an inner diameter of the annular energy distribution, an outer diameter of the annular energy distribution, a thickness of the annular energy distribution, and a depth of the focal region within the tissue.

[0039] According to some embodiments, a method comprises cooling a tissue using a window assembly that contacts an external surface of the tissue; generating, using an EMR source, an EMR beam having a transverse annular energy distribution and a wavelength in a range of about 1200 nm to 12000 nm; focusing, using optics, the EMR beam to a focal region located within the tissue; scanning, using a transverse scanning system, the focal region within the tissue; and controlling, using a controller, the EMR source to generate the EMR beam having a plurality of pulses, wherein at least one pulse of the plurality of pulses has a pulse duration of no less than about 100 microseconds. In some embodiments, the window comprises: a first window; a second window separate from the first window; and a coolant chamber located between the first window and the second window. The coolant chamber is configured to hold a coolant comprising a fluorocarbon-based fluid that does not substantially absorb the EMR beam.

[0040] In some embodiments of the method, at least one pulse of the plurality of pulses has a pulse energy of no more than about 100 mJ.

[0041] In some embodiments of the method, the method additionally comprises cooling, using a chiller, the coolant to a temperature in a range of about -20 °C to about 20 °C.

[0042] In some embodiments of the method, focusing the EMR beam is performed at a numerical aperture (NA) of at least about 0.2.

[0043] In some embodiments of the method, the method additionally comprises introducing an optical tissue clearing medium between the window assembly and the tissue, wherein the optical tissue clearing medium comprises at least one of glycerol, polyethylene glycol, and phosphate buffered saline.

[0044] In some embodiments of the method, the EMR source additionally comprises a beam shaper configured to shape the transverse annular energy distribution. In some versions of the method, the beam shaper comprises an axicon.

[0045] In some embodiments of the method, the method additionally comprises using the controller to control the EMR source to ensure that the window assembly cools the tissue to a predetermined temperature prior to generating the EMR beam.

[0046] In some embodiments of the method, the method additionally comprises using the controller to control the EMR source to ensure that the window assembly cools the tissue for a predetermined period of time prior to generating the EMR beam.

[0047] In some embodiments of the method, the method additionally comprises controlling at least one parameter of the EMR beam, including one or more of an inner diameter of the annular energy distribution, an outer diameter of the annular energy distribution, a thickness of the annular energy distribution, and a depth of the focal region within the tissue.

[0048] According to some embodiments, the system comprises: an EMR source configured to generate an EMR beam having a wavelength in a range between about 1400 nm and about 3500 nm; a collimator configured to collimate the EMR beam to a collimated beam width; a beam shaper comprising a first axicon and a second axicon, the beam shaper configured to shape the EMR beam into a lateral annular energy distribution, wherein the first axicon and the second axicon are separated along an optical axis by a separation distance, wherein an inner diameter of the annular energy distribution is related to the separation distance and a thickness of the annular energy distribution is related to the collimated beam width; an optical train configured to converge the EMR beam to a focal region located within a tissue at a numerical aperture of at least about 0.2; a beam scanning system configured to scan the focal region within the tissue; a window assembly located down-beam of the optical train, the window assembly configured to transmit the EMR beam and cool the tissue when placed in contact with an external surface of the tissue, wherein the window assembly comprises: a first window; a second window separated from the first window; and a coolant chamber located between the first window and the second window, wherein the coolant chamber is configured to contain a coolant comprising a fluorocarbon-based fluid that does not substantially absorb the EMR beam; a chiller configured to chill the coolant to a temperature in a range of about -20 °C to about 20 °C; a controller configured to control the EMR source to ensure that the window assembly cools the tissue to a predetermined temperature or for a predetermined time prior to generating the EMR beam; and, control the EMR source to generate the EMR beam having a plurality of pulses, wherein at least one pulse of the plurality of pulses has a pulse duration of no less than 100 microseconds; and, wherein at least one of the EMR source, the optical train, and the beam scanning system is configured to control one or more parameters of the EMR beam including one or more of the inner diameter of the annular energy distribution, the outer diameter of the annular energy distribution, the thickness of the annular energy distribution, and the depth of the focal region within the tissue. BRIEF DESCRIPTION OF DRAWINGS

[0049] Embodiments of the present disclosure will become more fully understood from the detailed description given herein below, and the accompanying drawings, wherein:

[0050] Figure 1 A device for electromagnetic radiation (EMR) treatment is schematically illustrated in accordance with some embodiments;

[0051] Figure 2 is a flowchart depicting a method for EMR treatment in accordance with some embodiments;

[0052] Figure 3A is a schematic illustration of an exemplary embodiment of a device for EMR treatment in accordance with some embodiments;

[0053] Figure 3B is Figure 3A a cross-sectional view of the device of along line B-B;

[0054] Figure 3C is a cross-sectional view of the device along line C-C; Figure 3A

[0055] Figure 3D is a detailed view of the device at circle D; Figure 3A

[0056] Figure 3E is a back isometric view of a contact window assembly according to some embodiments;

[0057] Figure 3F is a front isometric view of a contact window assembly according to some embodiments; Figure 3E

[0058] Figure 3G is a front view of a contact window assembly according to some embodiments; Figure 3E

[0059] Figure 3H is a side cross-sectional view of a window assembly according to some embodiments; Figure 3E

[0060] Figure 4A is a schematic diagram of an optical path layout for a simulated beam shaper according to some embodiments;

[0061] Figure 4B shows a lateral Gaussian mode according to some embodiments;

[0062] Figure 4C shows a lateral donut-shaped energy distribution at 0.5 mm before focus according to some embodiments;

[0063] Figure 4D shows a lateral donut-shaped energy distribution at 0.2 mm before focus according to some embodiments;

[0064] Figure 4E shows a lateral donut-shaped energy distribution at 0.1 mm before focus according to some embodiments;

[0065] Figure 4F shows an energy distribution of a Gaussian beam at 0.5 mm before focus according to some embodiments;

[0066] Figure 4G shows an energy distribution of a lateral donut-shaped (i.e., annular) energy distribution at 0.5 mm before focus according to some embodiments;

[0067] Figure 5A shows horizontal histology of a tissue sample from Study #1 discussed herein according to some embodiments;

[0068] ​​​​​Figure 5B shows vertical histology of tissue samples from Study No. 1 discussed herein, according to some embodiments;

[0069] Figure 5C shows horizontal histology of tissue samples from Study No. 1 discussed herein, according to some embodiments;

[0070] Figure 5D shows vertical histology of tissue samples from Study No. 1 discussed herein, according to some embodiments;

[0071] Figure 6A shows vertical histology of tissue samples from Study No. 2 discussed herein, according to some embodiments;

[0072] Figure 6B shows vertical histology of tissue samples from Study No. 2 discussed herein, according to some embodiments;

[0073] Figure 7A shows multiple vertical histology images of tissue samples from Study No. 3 discussed herein, according to some embodiments;

[0074] Figure 7B shows multiple horizontal histology images of tissue samples from Study No. 3 discussed herein, according to some embodiments;

[0075] Figure 7C shows multiple horizontal histology images of tissue samples from Study No. 3 discussed herein, according to some embodiments;

[0076] Figure 7D shows multiple horizontal histology images of tissue samples from Study No. 3 discussed herein, according to some embodiments;

[0077] Figure 7E shows multiple horizontal histology images of tissue samples from Study No. 3 discussed herein, according to some embodiments;

[0078] Figure 8 schematically illustrates an optical scheme for fractional treatment, according to some embodiments.

[0079] Figure 9A schematically illustrates an optical scheme for fractional treatment, according to some embodiments.

[0080] Figure 9B schematically illustrates an optical scheme for fractional treatment, according to some embodiments; and

[0081] Figure 10 shows an exemplary embodiment of a treatment system;

[0082] Figure 11A A front view of an exemplary embodiment of a treatment system is shown;

[0083] Figure 11B A side view of an exemplary embodiment of a treatment system is shown;

[0084] Figure 11C A cross-sectional view of an exemplary embodiment of a treatment system is shown; Figure 11B

[0085] Figure 12 A line scan pattern according to some embodiments is shown;

[0086] Figure 13 A schematic of a pre-objective scanning system is shown;

[0087] Figure 14 A diagram of an exemplary pre-objective scanning system is shown;

[0088] Figure 15 A cross-sectional view of a pre-objective scanning system in Figure 14 is shown;

[0089] Figure 16 An exemplary f-0 lens is shown;

[0090] Figure 17 A diagram of an exemplary pre-objective scanning system is shown;

[0091] Figure 18 A diagram of an exemplary pre-objective scanning system is shown;

[0092] Figures 19A-19C An exemplary scan pattern associated with a pre-objective scanning system in Figure 14 , Figure 17 and Figure 18 is shown;

[0093] Figure 20 A diagram of an exemplary pre-objective scanning system is shown;

[0094] Figure 21 An exemplary prism system of a pre-objective scanning system in Figure 23 is shown;

[0095] Figure 22 An exemplary scan pattern associated with Figure 25 is shown;

[0096] Figure 23 A diagram of an exemplary pre-objective scanning system is shown;

[0097] Figure 24 A diagram of an exemplary pre-objective scanning system is shown;​

[0098] Figure 25 is a schematic diagram of a rotating objective lens scanning system;

[0099] Figure 26 schematically depicts a one-dimensional (1D) beam scanning system according to some embodiments;

[0100] Figure 27 schematically depicts a two-dimensional (2D) beam scanning system according to some embodiments; and

[0101] Figure 28 It is a schematic diagram of a post-objective objective scanning system.

[0102] Note that the drawings are not necessarily drawn to scale. The drawings are intended to depict only general aspects of the subject matter disclosed herein and, therefore, should not be considered to limit the scope of the present disclosure. The systems, devices, and methods specifically described herein and illustrated in the drawings are non-limiting exemplary embodiments. DETAILED DESCRIPTION

[0103] Certain exemplary embodiments will now be described to provide a general understanding of the principles of structure, function, manufacture, and use of the apparatus and methods disclosed herein. One or more examples of these embodiments are shown in the accompanying drawings. Those skilled in the art will understand that the apparatus and methods specifically described herein and shown in the accompanying drawings are non-limiting exemplary embodiments, and that the scope of the present disclosure is limited solely by the claims. Features illustrated or described in conjunction with one exemplary embodiment may be combined with features of other embodiments. Such modifications and variations are intended to be within the scope of this disclosure.

[0104] Embodiments of the present disclosure are discussed in detail below with respect to fractionated treatments including skin rejuvenation and skin resurfacing, such as for skin resurfacing of acne, chicken pox and surgical scars, periorbital and perioral wrinkles, photoaging changes, facial pigmentary disorders, and stretch marks. Other treatments relevant to the present disclosure include treatment of skin pigmentary disorders such as melasma and other pigmentary disorders such as granuloma annulare.

[0105] The disclosed embodiments can be used without limitation to treat other pigmented and non-pigmented conditions and other tissue targets and non-tissue targets. Examples of pigmented conditions can include, but are not limited to, post-inflammatory hyperpigmentation (PIH), darkening of the skin around the eyes, dark circles, cafe-au-lait spots, Becker's nevi, Ota's nevi, congenital melanocytic nevi, lentigo (freckles), and lentigines. Other examples of pigmented tissue and structures that can be treated include, but are not limited to, structures rich in hemosiderin, pigment gallstones, tattooed tissue, and structures rich in lutein, zeaxanthin, rhodopsin, carotenoids, biliverdin, bilirubin, and hemoglobin. Examples of targets for treating non-pigmented structures, tissues, and conditions can include, but are not limited to, hair follicles, hair shafts, vascular lesions, infectious conditions, sebaceous glands, acne, and the like.

[0106] Methods of treating various skin conditions, such as for cosmetic purposes, can be implemented using the systems described herein. It should be appreciated that while such methods can be implemented by a physician, non-physicians, such as cosmetologists and other suitably trained personnel, can use the systems described herein to treat various skin conditions, with and without the supervision of a physician.

[0107] Furthermore, in the present disclosure, similarly named components of embodiments generally have similar features, so each feature of each similarly named component need not be described in full detail in particular embodiments. Furthermore, where linear or circular dimensions are used in the description of the disclosed systems, devices, and methods, such dimensions are used merely for purposes of illustration and not because such dimensions are necessary. One of skill in the art will appreciate that, for any geometric shape, equivalents of such linear and circular dimensions can be readily determined. The size and shape of systems and devices, and components thereof, can depend at least on the anatomy of the subject in which the systems and devices will be used, the size and shape of components with which the systems and devices will be used, and the methods and procedures in which the systems and devices will be used.

[0108] Generally, high numerical aperture (NA) optical treatment systems are described that can focus electromagnetic radiation (EMR) (e.g., a laser beam) to a treatment region in tissue. The focused laser beam can deliver optical energy to the treatment region without damaging surrounding tissue. The delivered optical energy can, for example, treat tissue in the treatment region of the dermis layer of the skin without affecting surrounding regions (e.g., the overlying epidermis layer, other portions of the dermis layer, etc.). In other implementations, the delivered optical energy can cause tattoo removal or alteration, or perform hemoglobin-related treatments.

[0109] Exemplary methods and apparatus for treating skin conditions with light or light energy are disclosed in U.S. Patent Application Publication No. 2016 / 0199132, entitled “Method and Apparatus for Treating Dermal Melasma,” and U.S. Provisional Application No. 62 / 438,818, entitled “Method and Apparatus for Selective Treatment of Dermal Melasma,” the entire contents of both of which are incorporated herein by reference.

[0110] In general, systems and corresponding methods for treating skin conditions are provided. As discussed in greater detail below, the disclosed systems and methods employ electromagnetic radiation (EMR) (such as a laser beam) to deliver a predetermined amount of energy to a target tissue. The EMR can be focused to a focal region, and the focal region can be translated or rotated in any direction relative to the target tissue. The predetermined amount of radiation can be configured to thermally destroy or otherwise damage portions of the tissue. In this manner, the predetermined amount of energy can be delivered to any location within the target tissue for treatment, such as to improve its appearance.

[0111] Referring now to Figure 1 , a system 100 for radiation therapy is shown. An electromagnetic radiation (EMR) source (e.g., a laser source) 110 generates an EMR beam (e.g., a laser beam) 112 having a wavelength (in a range of about 1000 nm to about 12000 nm, e.g., about 1550 nm). According to some embodiments, the EMR beam 112 has a transverse ring-shaped energy distribution (e.g., TEM01*) from the EMR source 110. According to other embodiments, a beam shaper 114 shapes the EMR beam to produce the transverse ring-shaped energy distribution. Figure 1A beam shaper 114 employing two axicons is shown. A first axicon 116 having a first wedge angle receives the EMR beam 112 and produces a Bessel beam 118. As the Bessel beam propagates, it forms a diverging annular energy distribution. The diverging annular energy distribution 120 is collimated by a second axicon 122 into a collimated EMR beam having a transverse annular energy distribution 124. According to some embodiments, the second axicon 122 has a second wedge angle that is substantially equal to the first wedge angle of the first axicon 116. The annular energy distribution 124 is then directed toward a focusing optic 128. Some examples of the focusing optic 128 include a converging optic (e.g., a plano-convex lens) and an axicon. The focusing optic 128 converges the EMR beam and directs it toward tissue 130 (e.g., skin). In some cases, the focusing optic converges the EMR beam with a numerical aperture (NA) of at least about 0.2 (e.g., about 0.3 to about 0.5). According to some embodiments, a window assembly 132 is positioned between focusing optics 128 and tissue 130. Window assembly 132 is substantially transparent at the wavelength of EMR beam 124. Exemplary window materials include glass, quartz, and sapphire. In some embodiments, window assembly 132 is cooled and used to cool tissue 130 during treatment. Generally, during operation of device 100, window assembly 132 is placed in contact with the outer surface of the tissue. According to some embodiments, window assembly 132 includes two windows, a first window 134 and a second window 136, with a cooling chamber 138 positioned between the two windows. The cooling chamber is configured to contain a coolant. In some embodiments, a coolant stream 140 flows through coolant chamber 138. In some embodiments, the coolant includes one or more of the following: a dielectric fluid, a fluorocarbon-based fluid, ethylene glycol, propylene glycol, water, and antifreeze. In most cases, the coolant is selected to be generally transmissive (e.g., greater than approximately 50%) at the wavelength of EMR beam 124. For example, an exemplary embodiment includes an EMR beam 124 having a wavelength of 1550 nm and a beam comprising a fluorocarbon-based fluid (e.g., Flourinert® from 3M). TMcoolant of the window assembly 132, the fluid being substantially transmissive at 1550 nm. In some embodiments, a medium 142 is placed between the bottom surface of the window assembly 132 and the outer surface of the tissue 130. In some versions, this medium 142 is used to match the refractive indices of the window assembly 132 and the tissue 130. In some other versions, the medium penetrates the tissue. Examples of the medium 142 include: glycerol, phosphate buffered saline (PBS), polyethylene glycol (PEG) 400, and other suitable biocompatible materials with a refractive index approximately equal to that of skin (e.g., approximately 1.4). In some embodiments, the system 100 further includes a controller 150 to control the EMR source 110. For example, in some embodiments, it is advantageous to control the EMR source 110 in response to the cooling of the tissue to ensure that only the cooled tissue is irradiated. In some cases, the controller 150 is configured to control the EMR source to ensure that the window assembly cools the tissue to a determined temperature before the EMR beam is generated. In some other cases, the controller 150 is configured to control the EMR source to ensure that the window assembly cools for a predetermined time before the EMR beam is generated. According to some embodiments, a temperature sensor 152 (e.g., a thermocouple or a thermistor) is used to directly measure the tissue temperature. Alternatively, the temperature of a component in thermal communication with the tissue is measured with a temperature sensor. For example, the temperature of the coolant as it exits the coolant chamber 138 can be used as an indicator of the tissue temperature.

[0112] In some embodiments, the controller 150 in communication with one or more of the EMR source 110, the beam shaper 114, and the focusing optics 128 is further configured to control one or more parameters of the EMR beam. Exemplary EMR beam parameters include the inner diameter of the annular energy distribution, the outer diameter of the annular energy distribution, the thickness of the annular energy distribution, and the depth of the focal region within the tissue. According to some embodiments, the EMR beam is scanned throughout the skin tissue to create multiple thermal damage locations within the tissue, for example, to provide fractionated treatment. Examples of systems and methods related to scanning a high-NA EMR beam are disclosed in U.S. Patent Application No. 16 / 219,801, entitled “Electromagnetic Radiation Beam Scanning System and Method,” and International Application No. PCT / US2018 / 065508, entitled “Scanning Systems for EMR-Based Tissue Treatment,” both of which are incorporated by reference herein.

[0113] Reference is made to Figure 2The flowchart 200 represents a method for irradiating tissue, according to some embodiments. First, the tissue is cooled 210 using a window assembly that is placed in contact with an external surface of the tissue. According to some embodiments, the window assembly includes two windows, a first window and a second window, with a cooling chamber located between the two windows. The cooling chamber is configured to hold a coolant. In some embodiments, a flow of coolant flows through the coolant chamber. In some embodiments, the tissue is cooled to a predetermined temperature before any subsequent step of the method 200. In some embodiments, the tissue is cooled for a predetermined time before any subsequent step. In some cases, cooling the tissue to a predetermined temperature and for a predetermined time can prevent thermal damage to the outer layer of the tissue (e.g., the epidermis) and thereby reduce downtime.

[0114] According to some embodiments, a temperature sensor is used to measure a temperature associated with the tissue, e.g., the temperature of a component that is in contact with (and thus in thermal communication with) the tissue. Exemplary temperature sensors include thermistors, thermocouples, and infrared temperature sensors. The temperature sensor in some cases directly senses the tissue temperature, while in other cases it senses the temperature of another material that is related to the tissue temperature (e.g., the coolant flowing out of a contact-type cooling assembly that is in contact with the tissue).

[0115] Next, an electromagnetic radiation (EMR) beam is generated 220. The EMR beam includes a transverse ring-shaped energy profile (e.g., TEM01*or a ring-shaped energy profile). The EMR beam is then focused 230 to form a focal region. Typically, one or more optical devices (e.g., a focusing lens and / or an axicon) are used to focus the EMR beam. In some versions, the EMR beam is focused at a numerical aperture (NA) of about 0.2 or greater. Finally, the EMR beam is directed 240 toward the tissue such that the focal region is at least partially located within the tissue (i.e., below the external surface of the tissue). In some versions, directing the EMR toward the tissue 240 additionally includes scanning the EMR beam such that the focal region moves within the tissue. Scanning the EMR is typically done in at least one of the three axes (e.g., two axes perpendicular to the optical axis and one axis parallel to the optical axis). For example, the focal region can be scanned laterally in the tissue, or the focal region can be scanned in depth within the tissue. In some embodiments of the method 200, an optical tissue-clearing medium is introduced into the tissue. For example, in some cases, the optical tissue-clearing medium is introduced onto the tissue surface between the tissue and the window assembly. In some embodiments, the method 200 additionally includes controlling at least one parameter of the EMR beam. Exemplary parameters of the EMR beam include the inner diameter of the ring-shaped energy profile, the outer diameter of the ring-shaped energy profile, the thickness of the ring-shaped energy profile, and the depth of the focal region within the tissue.

[0116] Exemplary embodiments

[0117] Referring now to Figure 3A , an example system 300 is shown with the front cover removed. A fiber laser source 310 outputs laser light. The example fiber laser source 310 is a CWEr-Yb laser with an average power of 20 W (e.g., IPG part number ELR-20-1550-LP by IPG Photonics Corporation of Oxford, MA). A collimator 312 collimates the laser light into a beam with a diameter of about 4 mm wide. The collimated laser beam is then shaped by a beam shaper 314 into a transverse ring (i.e., doughnut) energy distribution (e.g., TEM 01*). The laser beam is then directed along an optical system, ultimately being focused and directed out of a window assembly 316 of the bottom face of the example system 300.

[0118] Figure 3B A cross-sectional view of the example system 300 and beam shaper 314 taken along section line B-B in Figure 3A is shown. In Figure 3B , the beam shaper includes two identical axicons, a first axicon 320 and a second axicon 322. One example axicon is a Thorlabs part number AX2510-C, which has a physical wedge angle of 10°. The laser beam with a near single order mode (i.e., a Gaussian transverse energy distribution and M 2 ≤ 1.5) is shaped by the first axicon 320, first into a Bessel beam and then into a diverging transverse ring (i.e., doughnut) energy distribution. The second axicon collimates the diverging transverse ring energy distribution into a collimated transverse ring energy distribution. The beam shaper is configured such that the inner diameter of the transverse ring energy distribution is proportionally related to the separation distance between the first axicon 320 and the second axicon 322. According to an example embodiment, the inner diameter of the transverse ring energy distribution is nominally 4 mm. The laser beam now shaped into a transverse ring (i.e., doughnut) energy distribution propagates further along the optical path and ultimately exits the system 300 through the window assembly 316. Figure 3C An example system 300 and window 316 are shown along Figure 3AA cross-sectional view of the section line C-C in FIG. 3. The focusing optics 330 are positioned at the upper beam of the window 316 such that the laser beam converges as it transmits through the window assembly 316. Ultimately, the focusing optics 330 bring the laser beam to a focal region outside of the window assembly 316 such that, when the window assembly is placed in contact with tissue, the focal region is within the tissue. An exemplary focusing optic is an aspheric lens, Thorlabs part number A240-C with a nominal effective focal length of 8 mm. In some embodiments, a Z-mirror stage 331 houses the focusing optics 330 and is configured to adjust the position of the focusing optics 330 along the optical axis and thereby affect the depth of the focal region relative to the window 316 (i.e., the depth of the focal region within the tissue). One exemplary Z-mirror stage 331 is a Newscale PN:M3-FS by Newscale Technologies of Victor, New York. In some cases, the controller 150 is configured to control the Z-mirror stage in order to affect changes in the focal region depth.

[0119] Figure 3D A detailed view of the example system 300 is shown taken from a detail circle D in FIG. 3. In FIG. 3, Figure 3C A detailed view of the example system 300 is shown taken from a detail circle D in FIG. 3. In FIG. 3, Figure 3D The window assembly 316 is shown in more detail in FIG. 4. A first window 340 is shown proximate to the focusing optics 330. A second window 342 is shown separate from the first window 340. A coolant chamber 344 is positioned between the first window 340 and the second window 342. The coolant chamber 344 is hermetically sealed in order to contain the coolant as it flows through the coolant chamber 344. The coolant is heated by contact with the window assembly 316 and returned to the chiller. The coolant is then cooled by the chiller, e.g., a thermoelectric chiller (e.g., part number UC190 from Solid State Cooling of Wappingers Falls, New York), and recirculated to the window assembly 316. Disclosure related to window assemblies for cooling during irradiation is included in U.S. Patent Application No. 16 / 237,367 to Dresser et al., which is incorporated by reference herein. Reference is made to Figures 3A-3D Exemplary window assemblies disclosed will be described in more detail below.

[0120] An example window assembly 316 for cooling during irradiation is shown schematically in different views of Figures 3E-3H An example window assembly 316 for cooling during irradiation is shown schematically in different views of Figure 3E A top perspective view of the assembly 316 is shown (i.e., the portion of the cooling element 316 facing the EMR source / away from the target tissue). Figure 3F A bottom perspective view of the window assembly 316 is shown (i.e., the portion of the window assembly 316 facing the target tissue / away from the EMR source). Figure 3GA bottom view of the window assembly 316 is shown. Figure 3H A cross-sectional view of the window assembly 316 along the section line shown in Figure 3G A cross-sectional view of the window assembly 316 along the section line shown in Figure 3E and Figure 3G The frame 350 has three fiducials 352. The fiducials 352 correspond to mounts on the energy-based device (e.g., 300) from which radiation can be generated, thereby allowing the window assembly 316 to be removably attached and replaced on the energy-based device. According to some embodiments, the fiducials 352 can approximate one or more geometric forms, such as planes, lines, and points. According to some versions, the fiducials 352 comprise a portion of a kinematic mount (e.g., a Maxwell or a Kelv in mount). The three fiducials 352 of the window assembly 316 can lie in a plane. The exemplary window assembly 316 further includes a first window 340 sealed to the frame 350 by a first seal 354 and a second window 342 sealed to the frame 350 by a second seal 356. According to some embodiments, the first seal 354 and the second seal 356 comprise an adhesive. Examples of the adhesive can include a light-cured adhesive, a silicone, and an epoxy. According to other embodiments, the first seal 354 and / or the second seal 356 comprise a weld, a braze, or a solder and the edges of the corresponding first window 340 and / or second window 342 can be metallized, sputtered, or coated with a material (e.g., a metal) that allows this type of sealing. In addition, the second window 342 is secured to the frame 350 with one or more fasteners 358. As can be seen in Figure 3G and Figure 3H The fasteners 358 of the window assembly 316 comprise a clamp plate that is held in place by 3 machine screws, as can be seen in

[0121] Changes in the distance between the distal surface 360 and the optics focusing the EMR beam affect the working distance of the beam and the location of the final focal point within the tissue. According to some embodiments, the distal surface 360 of the second window 342 can be located at a predetermined geometry (e.g., orientation, position, etc.) relative to the fiducial 352. For example, in some versions, the second window 342 is positioned to be parallel to a plane approximated by the one or more fiducials 352 within a desired tolerance (e.g., 0.5 mrad). Further, the second window 342 can be located at a precise distance along the optical axis (e.g., z-axis) within a desired tolerance (e.g., 0.05 mm). Further, according to some embodiments, both the first window 340 and the second window 342 are positioned parallel and at a prescribed distance between them within a desired tolerance range (e.g., 0.5 mrad and 0.05 mm). For various reasons, in some embodiments, the distal surface 360 of the second window comprises a non-planar shape (e.g., convex or concave). For example, a convex distal surface 360 can facilitate compression of the tissue when placed in contact with the tissue.

[0122] Figure 3H A chamber 344 within the system 400 is depicted. The chamber 344 is bounded by the frame 350, the first window 340, and the second window 342. The chamber 344 can be sealed by the first seal 354 and the second seal 356. The chamber 344 is configured to contain a coolant. According to some embodiments, the coolant is supplied to the chamber 344 by a flow of coolant through one or more ports 362 in fluid communication with the chamber 344. According to some embodiments, the ports 362 can provide a flow of coolant from a coolant flow source in fluid communication with the ports 362. In some implementations, the coolant flow source can be in fluid communication with the ports 362 through one or more fittings 364. Figure 3E and Figure 3F Both a coolant supply fitting 364a and a coolant return fitting 364b are shown for supplying coolant to and returning coolant from the chamber 344.

[0123] According to some embodiments, the second window comprises a material with a high heat flux rate (e.g., quartz, sapphire, diamond, etc.). The higher heat flux rate can allow more heat to be transferred from the tissue surface to the coolant stream. Likewise, according to some embodiments, the first window 340 comprises a material with a lower heat flux rate (e.g., glass or a polymer). Embodiments with the first window 340 comprising a lower heat flux rate material can transfer less heat through the first window and into the coolant stream. Thus, condensation can occur more slowly compared to versions with the first window 340 comprising a high heat flux rate material. Furthermore, in some embodiments, the thickness of the first window (e.g., about 1 mm) is greater than the thickness of the second window (e.g., about 0.5 mm), allowing heat energy to be transferred more freely through the second window to occur. According to some versions, a non-condensing gas such as clean dry air, nitrogen, carbon dioxide, or argon can be blown against the first window to further prevent condensation.

[0124] Figure 4A An example optical layout 400 is shown, according to some embodiments. A collimated Gaussian beam 410 is incident and focused to propagate to a first axicon 412, which forms a Bessel beam 414. The Bessel beam 414 is incident and focused to propagate to a second axicon 416, which forms a collimated transverse ring (i.e., doughnut) energy distribution beam 418. The collimated transverse ring energy distribution beam 418 is incident and focused to propagate to an aspheric focusing optic 420, which forms a converging transverse energy distribution 422 focused to a focal region 424.

[0125] Figure 4B A first simulated Gaussian beam profile 430 of the collimated Gaussian beam 410 is shown. Figure 4C A first simulated transverse ring (i.e., doughnut) beam profile 432 of the converging transverse ring energy distribution 422 is shown, 0.5 mm in front of the focal region 424. Figure 4D A second simulated transverse ring beam profile 434 of the converging transverse ring energy distribution 422 is shown, 0.2 mm in front of the focal region 424. And, Figure 4E A third simulated transverse ring beam profile 436 of the converging transverse ring energy distribution 422 is shown, 0.1 mm in front of the focal region 424. The converging transverse ring energy distribution beam 422 has a lower irradiance on the beam profile than a Gaussian mode beam under the same conditions. Referring to Figure 4F A Gaussian energy profile 440 of a Gaussian beam is shown, 0.5 mm from the focal point. Figure 4G A transverse ring (i.e., doughnut) energy profile 442 of a transverse ring energy distribution beam is shown, 0.5 mm from the focal point. Figure 4F And Figure 4GThe two beams characterized have the same power (e.g., 1 W). However, the local maximum irradiance (e.g., 1.29 W / cm 2 ) of the Gaussian beam is much larger than that of the transverse ring energy distribution beam (e.g., 0.75 W / cm 2 ). This allows the transverse ring beam to deliver a smaller peak energy density to the outer layers of the skin (e.g., epidermis) while delivering the same amount of energy to the deeper layers of the skin (e.g., dermis). The reduction in peak local energy density in the transverse ring beam is controlled by varying the inner diameter width of the transverse ring energy distribution. A larger inner diameter pushes more energy to the outside of the beam and reduces the peak energy density (or power density) within the beam. Furthermore, both the peak local energy densities in the Gaussian and transverse ring energy distributions can be reduced by increasing the numerical aperture of the focusing optics 420.

[0126] Exemplary ex vivo studies

[0127] A number of studies were performed in accordance with some embodiments. The studies were performed using a continuous wave (CW) erbium-ytterbium fiber laser with a maximum average power of 20 W and a wavelength of 1550 nm (IPG Laser model: ELR-20-1550LP). The excised human tissue was irradiated using a high numerical aperture (e.g., NA greater than or equal to 0.4) focusing system. Fractionated irradiation was accomplished by pulsing the CW fiber laser as the human tissue was scanned relative to the focusing system on an X-Y translation stage. The human tissue was then sectioned, stained, and examined. Viability was tested using a nitroblue tetrazolium chloride (NBTC) stain. Specifically, the NBTC stain acts on proteins within the tissue. Once these proteins are damaged (e.g., heat denatured), they are no longer stained by the NBTC and appear unstained.

[0128] Study No. 1

[0129] Study No. 1 was performed to determine the pulse energy required to non-ablatively thermally damage tissue using a Gaussian beam. The parameters used in Study No. 1 are shown below:

[0130] Table 1 - Study No. 1 Parameters

[0131]

[0132] Figures 5A-5D The tissue sections in FIGS. 1-4 show some representative results from Study No. 1. Figure 5A A horizontal cross-section is shown after irradiation with a pulse of energy of about 10 mJ. Figure 5B A vertical cross-section is shown after irradiation with a pulse of energy of about 10 mJ. The NBTC staining demonstrates very slight heat denaturation of the proteins. In contrast, irradiation with a pulse energy of more than 10 mJ, e.g., about 40 mJ, shows significant thermal damage.Figure 5C Horizontal sections taken at approximately 300 microns below the tissue surface are shown after each 40 mJ pulse of irradiation. Also, Figure 5D Vertical sections of the tissue after each 40 mJ pulse of irradiation are shown. The conclusion drawn from Study No. 1 is that, given this set of parameters, 10 mJ per pulse is the threshold pulse energy below which little or no thermal damage occurs.

[0133] Study No. 2

[0134] Study No. 2 was performed to determine the effect of optical tissue clearing media on fractionated non-ablative ex vivo irradiation. The excised human tissue samples were placed in optical tissue clearing media for 4 hours prior to irradiation. The samples were immersed in a culture dish containing culture medium with the epidermis facing down. Two optical tissue clearing media were tested: phosphate buffered saline (PBS) and glycerol. The parameters used in Study No. 2 are shown below:

[0135] Table 2 - Study No. 2 Parameters

[0136]

[0137] In the glycerol soaked tissue samples, thermal damage was only visible at 20 mJ per pulse. At the lower test pulse energies (5 mJ, 7 mJ, and 10 mJ), there was no apparent thermal damage via NBTC viability staining. Some representative results from Study No. 2 are shown in Figure 6A to the tissue sections of Figure B. Figure 6A Vertical sections of glycerol soaked tissue irradiated with 20 mJ pulses are shown. Figure 6B Vertical sections of PBS soaked tissue irradiated with 20 mJ pulses are shown.

[0138] Study No. 3

[0139] Study No. 2 was performed to determine the effect of optical tissue clearing media on fractionated non-ablative ex vivo irradiation. The excised human tissue samples were placed in optical tissue clearing media for 4 hours prior to irradiation. The samples were immersed in a culture dish containing culture medium with the epidermis facing down. Two optical tissue clearing media were tested: phosphate buffered saline (PBS) and glycerol. The parameters used in Study No. 2 are shown below:

[0140] Table 3 - Study No. 3 Parameters

[0141]

[0142]

[0143] Reference Figures 7A-7E Histology results from Study #3 are described. Figure 7A Four histology images in Cartesian layout are shown, with glycerol soaked tissue above, PBS soaked tissue below, 10 mJ per pulse energy to the left, and 20 mJ per pulse energy to the right. In general, the thermal destruction is significantly broader and deeper with 20 mJ pulse energy than 10 mJ. Figure 7B A horizontal histology image of tissue soaked in glycerol and irradiated with 10 mJ pulse energy is shown. Figure 7C A horizontal histology image of tissue soaked in glycerol and irradiated with 20 mJ pulse energy is shown. Figure 7D A horizontal histology image of tissue soaked in PBS and irradiated with 10 mJ pulse energy is shown. Figure 7E A horizontal histology image of tissue soaked in PBS and irradiated with 20 mJ pulse energy is shown. In the horizontal histology of tissue irradiated with a transverse annular energy distribution, a ring-shaped lesion can be seen (e.g., Figure 7C ). The lesion that appears as a ring in horizontal histology is a three-dimensional thin-walled hollow lesion cone that reaches a point at a certain depth (e.g., 300 microns to 1000 microns) within the tissue. Within the lesion cone, there is healthy, unaffected tissue as shown by the ring-shaped lesion in horizontal cross-section (e.g., Figure 7C ) and the “Y”-shaped lesion in vertical cross-section (e.g., Figure 7A ). One benefit of this irradiation mode is that there is less epidermal damage compared to current fractionated irradiation techniques; and, the damaged epidermis is damaged in a small and narrow width (e.g., 1-100 microns) surrounded by healthy (i.e., unaffected) tissue.

[0144] Parameter Selection

[0145] The following table outlines parameters relevant to the practice of embodiments of the present disclosure:

[0146] Table 4 - Exemplary Parameters and Ranges

[0147]

[0148]

[0149] In some embodiments, aspects of the annular energy distribution are controllable. Figure 8 A pair of axicons 800 is shown, configured to produce an annular energy distribution. The relationship between the separation (S) 810 of the two axicons 800 and the large diameter 812 of the resulting annular beam can be expressed as:

[0150]

[0151] where n is the refractive index of the first and second axicons, and a is the wedge angle of the first and second axicons 800.

[0152] As described above, the collimated beam diameter 814 determines the annular energy distribution width 816 as it enters the axicon pair 800. Accordingly, in some embodiments, the width of the annular energy distribution 816 is controlled by varying the collimated beam diameter 814. For example, in some cases, a beam expander (e.g., a Gallian beam expander or a Keplerian beam expander) is used to expand (or reduce) the collimated beam diameter 814 before it reaches the axicon pair 800. The small (i.e., inner) diameter 818 can be expressed in terms of the large (i.e., outer) diameter 812 of the annular energy distribution as follows:

[0153]

[0154] where, is the small diameter 818; is the large diameter 812; and is the beam diameter 814. According to some embodiments, one or more parameters related to the annular energy distribution are controlled by a controller that manipulates the above-mentioned parameters (e.g., the axicon pair 800 separation distance 810 and / or the beam expander rate). For example, in some cases, the separation distance 810 between the axicon pair 800 can be electronically manipulated by using a motorized stage (e.g., Thorlabs PN: PT1-Z8). Likewise, in some cases (e.g., a Gallian beam expander), the optical path distance between the two optics controls the beam expansion (or beam reduction) rate of the beam expander. In this case, the motorized stage can also be used to control the width of the beam 814 as it enters the axicon pair 800.

[0155] Small diameter fraction treatments result in smaller lesions and faster healing. For example, it has been found that fraction lesions larger than a certain width (e.g., about 0.15 mm, 0.25 mm, or 0.5 mm) cause scarring in some individuals. Even smaller fraction lesion widths below the currently commercially achievable, minimum to threshold minimum fraction lesion width size will further minimize downtime. In particular, beam sizes smaller than a single cell (e.g., about 20 microns) result in practically minimal possible fraction lesions. As described above, in some cases, the above-described exemplary optical system causes thermal lesions of this scale to the tissue. In additional exemplary embodiments, small fraction lesions to this tissue are achieved by another exemplary optical system.

[0156] Further features and advantages will become apparent to those skilled in the art from a review of the following detailed description, taken in conjunction with the accompanying drawings. Therefore, except as specifically stated herein, the disclosed embodiments are not intended to be limited to the specific form or form of disclosure set forth. All publications and references, including but not limited to patents and patent documents, cited in this document are expressly incorporated herein by reference for the purpose of providing their disclosures.

[0157] Additional embodiments.

[0158] Reference is made to Figures 9A-9B Another embodiment is described that affects fractional damage on the scale of tens of microns. Reference is made to Figure 9A , which shows an optical scheme 900 that produces a Bessel beam focal region 910. Unlike a normal diffraction-limited focal region, a Bessel beam focal region has a focal width and a focal region length that can be decoupled from one another. Generally, the focal region length (i.e., depth of field) is related to the square of the focal region radius (e.g., the Rayleigh range). Decoupling the focal region length from the focal region width allows for the formation of a focal region that is very long (e.g., greater than 0.5 mm long) and also very narrow (e.g., less than about 0.1 mm wide).

[0159] Figure 9A An optical path that can be used to produce a long and narrow beam is schematically shown. In this configuration, three axicon lenses are used. A first axicon 912 and a second axicon 914 are used to shape the beam into a collimated annular beam 916, and a third axicon 918 is used to focus the beam into a Bessel beam focal region 910.

[0160] According to some example embodiments, the damage width of the fractional treatment is related to the width of the first lobe of the Bessel beam focal region 910. The half-width ω0of the first lobe of the Bessel beam focal region 910 is a function of the wavelength λ, the wedge angle a of the axicon, and the refractive index n of the axicon:

[0161]

[0162] Accordingly, according to some embodiments, this selection of optical parameters is achieved by selecting the axicon wedge angle of the third axicon 918. The following table illustrates some example first lobe diameters for a 1550 nm beam based on the axicon wedge angle.

[0163] Table 5 - Wedge angle to first lobe diameter (wavelength = 1550 nm)

[0164]

[0165]

[0166] The length of the treatment fraction is related to the length of the Bessel beam focal region 910. The length of the Bessel beam (e.g., depth of field [DOF]) 920 formed by the axicon is a function of the beam width at the axicon. When a ring beam is used, the focal region length is a function of the ring width 922. The ring width, in turn, is a function of the width of the collimated beam 924 (e.g., half of it) that is shaped to form the ring beam. The length of the Bessel beam can be approximated using the following equation:

[0167]

[0168] For example, for an output beam of 4 mm, a wavelength of 1550 nm, and a wedge angle of 20°, the length of the Bessel beam focal region is approximately 15 mm.

[0169] The working distance (WD) 926 between the end of the third focusing axicon 918 and the Bessel beam focal region 910 is a function of the inner diameter 928 of the doughnut 916. Referring to Figures 9A-9B The working distance 926 measured from the end of the axicon 918 can be approximated using the following equation:

[0170]

[0171] The above equation is derived from the following two equations for X1and X0. Figure 9B The relationship between these equations is illustrated.

[0172] X0= -r*tan(a)

[0173]

[0174] WD = X0+ X1

[0175] As can be seen from the above, the small (i.e., inner) diameter 928 of the ring beam energy distribution 916 affects the working distance 926. For example, a non-ring beam acted upon by an axicon results in a Bessel beam focal region beginning at the end of the axicon. In some embodiments, by controlling the small diameter 928 of the ring beam incident to the focusing axicon 918 and thereby affecting the working distance 926 of the focal region 910, the focal region 910 is controlled to a depth within the tissue (e.g., below the surface of the tissue). In some versions, the small diameter 928 of the ring beam 916 is a function of the separation between the first axicon 912 and the second axicon. The small diameter can be expressed in terms of the large (i.e., outer) diameter 930 of the ring beam energy distribution 916. Specifically, the small diameter 928 is equal to the large diameter 930 minus the diameter of the collimated beam 924, or:

[0176]

[0177] Figure 10 One example embodiment of a treatment system 1010 is shown. As shown in the figure, the treatment system 1010 includes a platform 1012, an emitter 1014, and a controller 1016. The platform 1012 can include one or more manipulators or arms 1020. The arms 1020 can be coupled to the emitter 1014 for performing various treatments on a target tissue 1022 of a subject 1024. Operation of the platform 1012 and the emitter 1014 can be directed manually by a user or using the controller 16 (e.g., via a user interface). In certain embodiments (not shown), the emitter can have a hand-held form factor and the platform 1012 can be omitted. In other embodiments, the platform can be a robotic platform and the arms can be communicatively coupled to the controller for manipulating the emitter.

[0178] The emitter 1014 and the controller 1016 (and optionally the platform 1012) can communicate with each other via a communication link 1026, which can be any suitable type of wired and / or wireless communication link carrying any suitable type of signals (e.g., electrical, optical, infrared, etc.) according to any suitable communication protocol.

[0179] Embodiments of the controller 1016 can be configured to control operation of the emitter 1014. In one aspect, the controller 1016 can control movement of the EMR 1030. As discussed in detail below, the emitter 1014 can include a source 1032 for emitting the EMR 1030 and a scanning system 1034 for manipulating the EMR 1030. As an example, the scanning system 1034 can be configured to focus the EMR 1030 to a focal region and to translate and / or rotate this focal region in space. The controller 1016 can send signals to the source 1032 via the communication link 1026 to command the source 1032 to emit the EMR 1030 with one or more selected characteristics, such as wavelength, power, repetition rate, pulse duration, pulse energy, focusing characteristics (e.g., focal volume, Rayleigh length, etc.). In another aspect, the controller 1016 can send signals to the scanning system 1034 via the communication link 1026 to command the scanning system 1034 to move the focal region of the EMR 1030 in one or more translation and / or rotation operations relative to the target tissue 1022.

[0180] Embodiments of the treatment system 1010 and method are discussed herein in the context of treating skin tissue, such as a dermal layer. However, the disclosed embodiments can be used without limitation to treat any tissue at any location of a subject. Examples of non-skin tissue can include, but are not limited to, mucosal tissue, genital tissue, internal organ tissue, and surface and subsurface regions of the gastrointestinal tract.

[0181] Example manual scanning system

[0182] In some embodiments, a handheld system 1100 is used that is manually scanned (i.e., manually moved by a clinician) over the treatment area. Figures 11A-11C An example embodiment that can be manually scanned is shown. Figure 11A A front view of the system 1100 is shown; Figure 11B A side view of the system 1100 is shown; and, Figure 11C A cross-sectional view of the system 1100 is shown. Referring to Figures 11A-11C The fiber laser outputs a laser beam through a collimator 1110. The laser beam can be of any wavelength. Details of the wavelength selection are described in detail above. A beam shaper 1112 acts on the collimated laser beam. As described in detail above, the beam shaper 1112 takes the collimated laser beam from the collimator 1110 and shapes it into a transverse annular energy distribution. As the cross-sectional view Figure 11C) shows that the beam shaper has a first axicon 1112A, a collimating lens 1112B, and a second axicon 1112C. Both axicons 1112A and 1112C are used to shape the beam. The collimating lens 1112B is used to align the laser beam onto the second axicon 1112C. Typically, axicons are very sensitive to misalignment, especially misalignment of the center. After the beam shaper 1112, the laser beam is then reflected by a first galvanometer mirror 1114 and directed into and through a beam expander 1116. The beam expander is a Keplerian beam expander and includes a first positive optical element 1116A that focuses the beam to an intermediate focus and a second positive optical element 1116B that collimates the laser beam. In some cases, one or more of the beam expander optics are dynamic and can be moved along the optical axis. A linear stage 1116C moves the second positive optical element 1116B along the optical axis. One example linear stage is a Newscale M3-LS-3.4-15 from Newscale Technologies of Victor, New York. The beam expander 1116 expands the collimated annular beam, for example, by a factor between 2-20 times. Upon exiting the beam expander 1116, the laser beam is reflected by a static folding mirror 1118, focused by an objective lens 1119 (e.g., an aspherical focusing optic, such as a Schott® aspherical lens PN: AFL25-40 from Schott® in Jena, Germany), reflected by a second galvanometer mirror 1120, and directed out of a contact window 1122. In some versions, the beam expander is an afocal relay system that is placed at a conjugate distance between the first galvanometer mirror 114 and the objective lens 1119. The contact window 1122, like many of the windows described in detail above, includes a first window 1122A; a second window that is separate from the first window 1122B; and a coolant chamber 1122C between the first window 1122A and the second window 1122B. The second window 1122B has a convex tissue contact surface (i.e., outer surface). This shape is advantageous in some cases because it helps to ensure positive contact with the tissue being treated and is easier to slide off of the tissue.

[0183] Figures 11A-11C The handheld system 1100 described in FIG. 11 is used to manually treat an area. As the clinician moves the handheld system 1100 over the tissue being treated, the second galvanometer mirror 1120 scans the rows of points on the skin surface from side to side. Referring now to FIG. 12, Figure 12 shows an example row of scanned points 1200. The example row 1200 includes eight individual points 1210 at which laser energy is delivered. As Figure 12As shown in FIG. 12, eight points 1210 are scanned in order from top to bottom (i.e., A-H). After the last point (i.e., the H point) is delivered energy, the row scan is repeated and begins again. The width of the row 1212 is approximately equal to the number of points 1210 multiplied by the pitch 1214 (i.e., the distance between adjacent points). Referring briefly again to Figures 11A-11C The second galvanometer mirror 1120 of the handheld system 1100 scans the row along a manual scan direction 1216 that is generally perpendicular to the direction of the row scan 1200.

[0184] Example beam scanning system

[0185] In some embodiments, beam scanning systems and methods are provided. Described below are disclosures related to these embodiments and beam scanning systems and methods. Generally, beam scanning systems and methods can be categorized as one or more of the following types: pre-objective scanning, objective scanning, and post-objective scanning. Pre-objective scanning includes embodiments in which a beam is scanned (e.g., deflected, tipped, and / or tilted) before being directed to impinge on an objective lens (i.e., on-objective beam). Objective scanning includes embodiments in which scanning (e.g., deflection, tipping, and / or tilting) of a beam is performed at an objective lens, e.g., by moving the objective lens. Post-objective scanning includes embodiments in which scanning (e.g., deflection, tipping, and / or tilting) is performed after an objective lens (i.e., off-objective beam).

[0186] Pre-objective scanning

[0187] Figure 13 is a schematic diagram of a pre-objective scanning system 2100 that includes an objective lens 2110 and a scanning unit 2112. The scanning unit 2112 can receive a laser beam 2104 from a laser source 2102 and direct the laser beam 2104 to the objective lens 2110. The objective lens 2110 can receive the laser beam 2104 and direct a focused laser beam 2106 to a focal volume 2108 in a treatment region of a tissue 2116 (e.g., skin). The scanning unit 2112 can change the direction of the laser beam 2104 that is directed to the objective lens 2110. For example, the scanning unit 2112 can change the direction of the outgoing laser beam along one or more scan directions. Changes in the direction of the laser beam 2104 that impinges on the objective lens 2110 can cause the focal volume 2108 to track a treatment path 2114 in the tissue 2116. The focal volume 2108 traverses the treatment path 2114 at a scan rate. The scanning unit 2112 includes one or more optical elements that are capable of directing the laser beam 2104 (or a portion of the laser beam 2104) to the objective lens 2110. The pre-objective scanning system 2100 can include a contact surface (e.g., as described in more detail below) that is configured to contact the tissue 2116. The contact surface can be configured to contact the tissue 2116 at a contact point 2118. The contact point 2118 can be located at a distance 2120 from the objective lens 2110. The distance 2120 can be less than or equal to the focal length of the objective lens 2110. The contact surface can be configured to contact the tissue 2116 at a contact point 2118. The contact point 2118 can be located at a distance 2120 from the objective lens 2110. The distance 2120 can be less than or equal to the focal length of the objective lens 2110. Figure 24As shown in FIG. 21, the contact surface can be positioned between the objective lens 2110 and the tissue 2116. The contact surface can apply pressure to the surface of the tissue 2116 and allow heat to dissipate from the surface of the tissue 2116.

[0188] Figure 14 FIG. 22 is an illustration of an example pre-objective scanning system 2200. The scanning system 2200 includes a polygon scanner 2202 that can receive an incident laser beam 2104 (e.g., from a laser source 2102) and direct the incident laser beam 2104 toward an objective lens 2110 (e.g., an f- theta lens). The exit direction of the laser beam 2104 (e.g., the angle of incidence at which the laser beam 2104 hits the objective lens 2110) can determine the location (e.g., in the x-y plane) of a focal volume 2108 in the tissue 2116. According to some embodiments, the laser source 2102 provides a plurality of laser pulses that result in a plurality of corresponding focal volumes. The distance between two focal volumes resulting from successive laser pulses is a focal volume spacing.

[0189] The polygon scanner 2202 can include a plurality of reflective surfaces (e.g., 2202a-c). The polygon scanner 2202 can rotate about an axis 2204 along a rotation direction 2206. As the reflective surfaces 2202a-c rotate about the axis 2204 (e.g., the angular position of the reflective surfaces 2202a-c relative to the axis 2204 changes), the angle of incidence of the incident laser beam 2104 in the y-z plane changes. This changes the direction of the exit laser beam 2104 along a first scan direction (e.g., along the y-axis). For example, if a reflective surface (e.g., 2202b) rotates about the axis 2204 along the rotation direction 2206, the direction of the exit laser beam sweeps from a higher y value to a lower y value.

[0190] The axis 2204 can be tilted / rotated about the z-axis and / or the x-axis. This can cause the angle of incidence of the incident laser beam 2104 in the x-z plane to change, which changes the direction of the exit laser beam 2104 along a second scan direction (e.g., along the x-axis). The rotation of the polygon scanner 2202 and the rotation / tilt of the axis 2204 can allow the direction of the exit laser beam 2104 to be changed, which can result in a scan of the exit laser beam 2104 in the x-y plane.

[0191] Based on changes in the direction of the outgoing laser beam 2104, the objective lens 2110 can track the focal volume 2108 along one or more treatment paths in the tissue 2116. For example, changes in the direction of the outgoing laser beam 2104 due to rotation of the polygon scanner 2202 can cause the focal volume 2108 to move along the y-axis. Changes in the direction of the outgoing beam due to tilting of the axis 2204 can cause the focal volume 2108 to move along the x-axis. In one implementation, the objective lens pre-scan system 2200 can move along the x-axis relative to the tissue 2116. This can cause the position of the focal volume 2108 to be tracked along the x-axis.

[0192] The focal volume 2108 can also be moved along a third treatment path, i.e., along the z-axis. This can be accomplished by changing the objective lens 2110 along the z-axis (e.g., moving away from or toward the tissue 2116). Alternatively or additionally, a lens 2240 can be placed in the optical path of the incoming or outgoing laser beam 2104. By changing the position of the lens 2240 along the beam propagation direction 2242 (also referred to as the optical axis), the position of the focal volume 2108 can be tracked along the z-axis (e.g., the depth of the tissue 2116).

[0193] Figure 15 A beam folding plane 2300 for the objective lens pre-scan system 2200 is shown. By folding the scan system 2200 around the beam folding plane 2300, the scan system 2200 can be made compact (e.g., by reducing the extent of the scan system 2200 along the z-axis). For example, this can be accomplished by placing a mirror (e.g., a flat mirror) in the beam folding plane and orienting the mirror parallel to the x-y plane.

[0194] Figure 16 An example f-0 lens 2400 that can be used as an objective lens in the objective lens pre-scan system 2200 is shown. The incoming laser beam 2104 can impinge on a reflective surface 2402 (e.g., the reflective surface 2202b of the polygon scanner 2202), which can direct the outgoing laser beam 2104 to the f-0 lens 2400. The orientation of the reflective surface 2402 can determine the angle of incidence (e.g., the angle of incidence in the y-z plane) at which the outgoing laser beam 2104 impinges on the f-0 lens. The angle of incidence can determine the position of the focal volume 2108 (e.g., along the y-axis).

[0195] Figure 17is an illustration of an example objective pre-scan system 2500. The scan system 2500 includes a mirror system that can receive a laser beam 2104 (e.g., through an optical fiber 2520) and direct the laser beam 2104 toward an objective 2110 (e.g., an f-theta lens). The direction of the exiting laser beam 2104c can determine the location of the focal volume 2108 in the tissue 2116 (e.g., in the x-y plane).

[0196] The mirror system can include two scanning mirrors. The first scanning mirror 2506 can rotate (e.g., clockwise, counterclockwise, etc.) about a first axis 2522, and the second scanning mirror 2508 can rotate (e.g., clockwise, counterclockwise, etc.) about a second axis 2524. As the first scanning mirror 2506 rotates, the angle of incidence of the incoming laser beam 2104 on the mirror 2506 changes. This changes the direction of the exiting laser beam 2104b along a first scan direction (e.g., along the y-axis). As the second scanning mirror 2508 rotates, the angle of incidence of the laser beam 2104b on the scanning mirror 2508 changes. This changes the direction of the exiting laser beam 2104c along a second scan direction (e.g., along the x-axis). The rotation of the first scanning mirror 2506 and the second scanning mirror 2508 can allow the direction of the exiting laser beam 2104c to be changed, which can result in a scan of the exiting laser beam 2104c in the objective plane.

[0197] Based on the changes in the direction of the exiting laser beam 2104c, the objective 2110 can track the focal volume 2108 (not shown) along one or more treatment paths in the tissue 2116. For example, changes in the direction of the exiting laser beam 2104c due to the rotation of the first scanning mirror 2506 can cause the focal volume 2108 to move along a first treatment path. Changes in the direction of the exiting laser beam 2104c due to the rotation of the second scanning mirror 2508 can cause the focal volume 2108 to move along a second treatment path.

[0198] The scan system 2500 can include a lens 2540 that can be placed in the optical path of the laser beam 2104a, 2104b, or 2104c. By changing the position of the lens 2540 along the direction of the beam propagation, the position of the focal volume 2108 can be tracked along the depth of the tissue 2116.

[0199] In some implementations of the scan mirror system, the changes in the direction of the laser beam 2104b by the first scanning mirror 2506 can be large. This can prevent the laser beam 2104b from hitting the second scanning mirror 2508. In addition, large angles of incidence of the laser beam 2104b on the second scanning mirror 2508 can result in a curved treatment path of the focal region. By including a third scanning mirror between the first scanning mirror 2506 and the second scanning mirror 2508, these effects can be prevented / reduced. Figure 18is an illustration of an example pre-objective scanning system 2600 that includes a third scanning mirror 2507 downstream of the first scanning mirror 2506 and upstream of the second scanning mirror 2508. The third scanning mirror 2507 can allow for a smaller second scanning mirror 2508 and can prevent / reduce curvature of the focus volume treatment path.

[0200] Figures 19A-19C Various scan patterns of an exit beam (e.g., exit laser beam 2104) from a scanning unit 2112 (e.g., polygon scanner 2202, mirror system 2502, etc.) are shown. Figure 19A A first scan pattern is shown in which the exit beam scans in the following order: (a) a left-to-right movement (e.g., along the x-axis), (b) an up-to-down movement (e.g., along the y-axis), and (c) a right-to-left movement (e.g., along the negative x-axis). Figure 19B A second scan pattern is shown in which the exit beam scans in the following order: (a) a left-to-right movement (e.g., along the x-axis), (b) a superposition of an up-to-down movement and a right-to-left movement, and (c) a left-to-right movement. Figure 19C A third scan pattern is shown in which the exit beam scans in the following order: (a) a superposition of a left-to-right movement and an up-to-down movement, and (b) a superposition of a right-to-left movement and an up-to-down movement. The movements of the beam (e.g., left-to-right, right-to-left, up-to-down, etc.) can be obtained by clockwise or counter-clockwise rotation of the scanning mirrors 2506, 2507, 2508, or by rotation / axis tilting of the polygon scanner 2202.

[0201] Figure 20 is an illustration of an example pre-objective scanning system 2800. The scanning system 2800 includes a prism system 2802 that can receive an incident laser beam 2104 (e.g., through an optical fiber 2820) and transmit an exit beam 2105 (see Figure 21 ) to an objective lens 2110 (e.g., f- theta lens) toward a tissue 2116. The direction of the exit beam 2105 can determine the location of the focus volume 2108 in the tissue 2116.

[0202] Figure 21A prism system 2802 that can be used with the objective front scanning system 2800 is shown. The prism system 2802 includes a first prism 2806 and a second prism 2808, which can rotate about a common axis 2822. Each of the prisms can change the direction of an incident light beam by a characteristic angle. If the first prism 2806 and the second prism 2808 are both perfectly aligned, the direction of the incident laser beam is changed by twice the characteristic angle. If the first prism 2806 and the second prism 2808 are perfectly misaligned, the direction of the incident laser beam remains unchanged. For all other orientations of the prisms 2806 and 2808, the direction of the incident laser beam can be changed by an angle that ranges between zero degrees and twice the characteristic angle.

[0203] If the prisms 2806 and 2808 are both rotated at the same angular velocity (e.g., their relative orientation does not change during rotation), the outgoing beam 2105 is scanned along a circular treatment path. If the prisms 2806 and 2808 are rotated at different angular velocities, their relative orientation will change during rotation. For example, the prism pair will oscillate between a perfectly aligned state (the direction of the outgoing beam is offset by twice the characteristic angle) and a perfectly misaligned state (the direction of the outgoing beam remains unchanged).

[0204] Figure 22 A scan pattern of the outgoing beam 2105 resulting from the prism system 2802 is shown, where the angular velocities of the first prism and the second prism are different. The outgoing beam forms a spiral pattern - the outgoing beam 2105 can spiral inwards (e.g., until it reaches the center), and subsequently can spiral outwards.

[0205] Figure 23is an illustration of an example pre-objective scanning system 3100. The scanning system 3100 includes a scanning unit 3102 coupled to an optical fiber 3110 that can guide the laser beam 2104. The scanning unit 3102 can include a first actuator 3106 and a second actuator 3108. The first actuator can rotate a portion of the optical fiber 3110 (e.g., the fiber end proximate to the objective lens 3112) about the x-axis. This changes the direction of the outgoing laser beam 2104 along a first scan direction (e.g., along the y-axis). The second actuator 3108 can rotate a portion of the optical fiber 3110 (e.g., the fiber end proximate to the objective lens 3112) about the y-axis. This changes the direction of the outgoing laser beam 2104 along a second scan direction (e.g., along the x-axis). Actuation of the first and second actuators can allow for changing the direction of the outgoing laser beam 2104, which can result in a scan of the outgoing laser beam 2104 in the plane of the objective lens 3112 (e.g., the x-y plane). Based on the changes in the direction of the outgoing laser beam 2104, the objective lens 3112 (e.g., an f- theta lens) can track the focal volume 2108 along one or more treatment paths in the tissue 2116.

[0206] Figure 24 is an illustration of an example pre-objective scanning system 3200. The scanning system 3200 includes a scanning unit 3202 coupled to an optical fiber 3210 (e.g., rigidly coupled) that can guide the laser beam 2104. The scanning unit 3202 can include a six-axis actuator 3206 and a support arm 3208. A portion of the optical fiber 3210 can be rigidly coupled to a mounting location 3230 on the six-axis actuator 3206. The support arm 3208 can support a portion of the optical fiber proximate to the tissue 2116.

[0207] The six-axis actuator 3206 can move the optical fiber 3210 along the x-axis, the y-axis, and the z-axis. Additionally or alternatively, the six-axis actuator 3206 can rotate the optical fiber 3210 about the x-axis, the y-axis, and the z-axis. An end of the optical fiber 3210 can be coupled to an objective lens 3212 that can focus the outgoing laser beam 2104 to the focal volume 2108 in the tissue 2116. The pre-objective scanning system 3200 can also include a contact surface 3216 that can be located in the optical path of the outgoing laser beam 2104 between the objective lens 3212 and the tissue 2116.

[0208] The focal volume 2108 can be moved along a first treatment path (e.g., along the x-axis) by rotating the optical fiber about the y-axis. The focal volume 2108 can also be moved along a second treatment path (e.g., along the y-axis) by rotating the optical fiber about the x-axis. In some implementations, it can be desirable to vary the distance between the end of the optical fiber 3210 and the tissue 2116 (e.g., by moving the end of the optical fiber along the z-axis) during rotation (e.g., along the x-axis, the y-axis, etc.) to ensure that the focal volume 2108 remains at a fixed depth in the tissue 2116.

[0209] Objective scanning

[0210] Figure 25 is a schematic diagram of a rotating objective scanning system 3300. The rotating objective scanning system 3300 can receive a laser beam 3304 from a laser source 3302. The scanning system 3300 includes an objective (not shown) that focuses the laser beam 3304 and directs the focused laser beam 3306 to a focal region 3308 in a treatment region 3310 of tissue 3311 (e.g., skin). As the objective moves (e.g., relative to the scanning system 3300 and / or due to movement of the entire scanning system 3300), the focal region can track a treatment path 3312 throughout the treatment region 3310. The treatment path 3312 can have a path geometry (e.g., circular, elliptical, etc.). The scanning system 3300 includes optical elements that are capable of directing the laser beam 3304 (or a portion of the laser beam 3304) toward the moving objective.

[0211] The scanning system 3300 can also include an interface (also referred to as a “pedestal,” “window,” or “contact surface”) that can stabilize the treatment region 3310 and / or facilitate control and uniformity of radiation distribution. For example, the interface can immobilize the treatment region 3310 by applying pressure and / or by including a gel pad between the interface and the treatment region. The pressure applied by the interface on the treatment region 3310 can be detected by a pressure detector. The interface can also include a contact sensor that detects relative motion between the skin and the interface. The pressure provided by the interface on the treatment region can also cause the volume of the treatment region being irradiated to become blanked (or some blood removed therefrom). This can result in selective absorption of the focused laser beam 3306 by the treatment region (e.g., pigmented cells in the treatment region), while reducing the risk of unwanted damage to blood vessels.

[0212] The interface can cool / dissipate heat from the treatment region 3310, which can be generated, for example, by heating of the treatment region 3310 by the focused laser beam 3306. The interface can be made of a material suitable for heat dissipation (e.g., sapphire, diamond, glass, etc.). In some embodiments, the interface can include a cooling system that can prevent the temperature of the treatment region from exceeding a threshold temperature. The cooling system can include a temperature sensor that can detect the temperature of the treatment region. If the temperature exceeds the threshold temperature, the user can be notified and / or a cooling unit (e.g., a Peltier device, a cryogenic spray, a cold pipe, etc.) can be activated to cool the treatment region.

[0213] Rotating objective scanning systems can have various embodiments. Two exemplary embodiments of rotating objective scanning systems include in-plane rotating objective scanning systems and transverse rotating objective scanning systems, both of which will be described below.

[0214] Figure 26 A system 3400 for scanning an electromagnetic radiation (EMR) beam 3402 is schematically depicted in accordance with some embodiments. A motor 3404 generates a rotational movement 3406. The motor 3404 is operatively coupled to a reciprocating mechanism 3408 such that the rotational movement 3406 drives the reciprocating mechanism 3408. The reciprocating mechanism 3408 converts the rotational movement 3406 to a reciprocating movement 3410 that generally acts linearly along a first scan axis 3412 (e.g., an x-axis). In accordance with some embodiments, the reciprocating mechanism includes one or more of: a cam and follower, a crank and slider, a Scotch yoke, and a multi-link mechanism. In accordance with some embodiments, the reciprocating movement 3410 moves in multiple strokes (e.g., two strokes, a forward stroke and a backward stroke). Generally, the reciprocating mechanism 3408 is configured to provide the reciprocating movement 3410 with a constant velocity. In other words, the reciprocating movement 3410 has a substantially flat velocity profile over some portions of at least one stroke.

[0215] Embodiments of constant velocity can employ a predetermined or desired constant velocity. For example, the desired constant velocity can be selected from a range of about 2 mm / S to about 5 m / S. In certain embodiments, the constant velocity can be a selected percentage of the desired constant velocity. As an example, the selected percentage can be selected from a range of about 10% to about 90% (as an example, about 50%) of the desired constant velocity.

[0216] The stroke portion of the reciprocating movement 3410 that provides the constant velocity can vary. For example, the stroke portion with constant velocity can be selected from a range of about 5% to about 95% (e.g., at least about 10%).

[0217] The focusing optic 3414 is operatively coupled to the reciprocating mechanism 3408 such that it experiences and moves according to the reciprocating movement. The focusing optic 3414 is configured to focus the EMR beam 3402 along an optical axis 3418 to a focal point 3416. The reciprocating movement 3410 of the focusing optic 3414 thereby moves the focal point 3416 and the optical axis 3418 along the first scan axis 3412.

[0218] According to some embodiments, the EMR beam 3402 is generated by an electromagnetic radiation (EMR) source 3420. Examples of EMR sources are described in detail below. The EMR beam 3402 is delivered from the EMR source 3420 and directed by an optical system 3422 onto the focusing optic 3414. Generally, the optical system 3422 includes one or more reflecting and / or transmitting optics. According to some embodiments, the optical system 3422 includes one or more moving dynamic optical elements 3424. For example, a dynamic optical element 3424 in the form of a reflector placed along the optical axis 3418 is mechanically fixed to the focusing optic 3414 and thus experiences and moves according to the reciprocating movement 3410. As discussed in more detail below, the EMR source 3420 can be configured to operate in a pulsed mode according to a predetermined repetition rate. The relationship between the repetition rate of the EMR source and the constant velocity of the reciprocating movement 3410 can determine a nominal spacing between successive pulses of focus along the first scan axis 3412.

[0219] According to some embodiments, a housing 3426 is disposed along the optical axis between the focusing optic 3414 and the focal point 3416. The housing 3426 is configured to contact a target surface via a contact surface, such as a surface of a target tissue 3428. As shown in the figure, the focal point 3416 is positioned below the beam of the surface of the target tissue 3428. The housing 3426 will be described in more detail below. In one embodiment, the contact surface can be configured to cool the target tissue 3428. In another embodiment, one or more sensors (e.g., pressure sensors, contact sensors, temperature sensors, etc.) can be located within the housing and configured to measure one or more variables of the target tissue. The one or more variables can include at least one of pressure, contact between the contact surface and the target tissue, and temperature

[0220] According to some embodiments, a controller 3430 is used to control one or more of the motor 3404, the reciprocating mechanism 108, and the EMR source 3420. In some versions, the controller 3430 takes input from one or more sensors 3432 that measure at least one of the rotational movement 3406 and the reciprocating movement 3410.

[0221] Figure 27A system 3500 that scans an electromagnetic radiation (EMR) beam in two axes is schematically depicted. A motor 3502 generates a rotational movement 3504 and delivers it to a reciprocating mechanism 3506 that converts the rotational movement 3504 to a reciprocating movement 3508 along a first scan axis 3510. According to some embodiments, the reciprocating movement 3508 comprises a linear stroke and has a constant velocity over a portion of the linear stroke. A focusing optic 3512 is mechanically fixed to the output of the reciprocating mechanism 3506 such that it experiences the reciprocating movement 3508 and moves according to it. An intermittent mechanism 3514 is operably coupled with the reciprocating mechanism 3506. The intermittent mechanism 3514 intermittently outputs an intermittent movement 3516. According to some embodiments, the intermittent mechanism comprises one or more of: a ratchet mechanism, an intermittent working wheel mechanism, a cam mechanism and an intermittent gear mechanism. According to some embodiments, the intermittent movement 3516 is linear and generally acts along a second scan axis 3518, which is generally orthogonal to the first scan axis 3510.

[0222] According to some embodiments, the intermittent mechanism 3514 is configured to introduce the intermittent movement 3516 when the reciprocating movement 3508 is at or near a specific position, for example at the beginning of the stroke, in the middle of the stroke or at the end of the stroke.

[0223] According to some embodiments, a controller 3530 is used to control one or more of the motor 3502, the reciprocating mechanism 3506 and the intermittent mechanism 3514. In some versions, the controller 3530 acquires input from one or more sensors 3532 that measure at least one of the rotational movement 3504, the reciprocating movement 3508 and the intermittent movement 3516.

[0224] Post objective lens scanning

[0225] Figure 28 is a schematic illustration of a post objective lens scanning system 3600. The post objective lens scanning system 3600 includes an objective lens 3610 and a scanning unit 3612. The objective lens 3610 can receive a laser beam 3604 from a laser source 3602 and direct a focused laser beam 3606 to the scanning unit 3612. The scanning unit 3612 can receive the focused laser beam 3606 and direct it to a focal region 3608 in a treatment region of tissue 3616 (e.g., skin). The scanning unit 3612 can allow the focal region 3608 to track a treatment path 3614. The scanning unit 3612 includes one or more optical elements that can direct the focused laser beam 3606 (or a portion of the focused laser beam 3606) toward the skin.

[0226] Example parameters according to some embodiments of pre- and post- objective lens beam scanners are disclosed in the following table:

[0227] Example scan parameters

[0228]

[0229]

[0230] The subject matter described herein can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structural means disclosed in this specification and structural equivalents thereof, or in combinations of them. The subject matter described herein can be implemented as one or more computer program products, such as one or more computer program tangibly embodied in information carrier (e.g., in one or more machine-readable storage media), or in a propagated signal, for execution by, or to control the operation of, data processing apparatus (e.g., a programmable processor, a computer, or multiple computers). A computer program (also known as a program, software, software application, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file. A program can be stored in a portion of a file that holds other programs or data, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or code portions). A computer program can be deployed for execution on one computer or on multiple computers at one site or distributed across multiple sites and

[0231] The processes and logic flows described in this specification, including the method steps of the subject matter described herein, can be performed by one or more programmable processors executing one or more computer programs to perform functions of the subject matter described herein by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus of the subject matter described herein can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0232] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0233] To provide for interaction with a user, the subject matter described herein can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0234] The technology described herein can be implemented using one or more modules. As used herein, the term “module” refers to computing software, firmware, hardware, and / or various combinations thereof. At a minimum, however, a module is not to be interpreted as software per se, or as a piece of software that is not implemented on hardware, firmware, or recorded on a non-transitory processor readable storage medium (i.e., modules are not software per se). Instead, a “module” should be interpreted as a hardware component that includes at least some physical, tangible hardware, such as a processor or a computer, regardless of whether software or firmware is used to implement one or more functions of the module. Two different modules can share the same physical hardware (e.g., two different modules can use the same processor and network interface). The modules described herein can be combined, integrated, separated, and / or duplicated to support various applications. Also, a function performed at a particular module can be performed at one or more other modules and / or by one or more other devices instead of or in addition to the function performed at the particular module. Further, the modules can be implemented across multiple devices and / or other components local or remote to one another. Additionally, the modules can be moved from one device and added to another device, and / or included in both devices.

[0235] The subject matter described herein can be implemented in a computing system that includes a back end component (e.g., a data server), a middleware component (e.g., an application server), or a front end component (e.g., a client computer having a graphical user interface or a web browser through which a user can interact with an implementation of the subject matter described herein), or any combination of such back end, middleware, and front end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), e.g., the Internet.

[0236] Approximating language can be used herein to convey the approximate but not exact nature of one or more parameters. For example, an “approximately” x can mean x plus or minus 10% or some other reasonable amount. Approximating language can be applied to quantitative as well as qualitative values. Such approximating language can be applied to values of any range, including ranges of time, distance, frequency, and / or wavelength. Such approximating language can be applied to any value reported herein, whether explicitly reported or not. As used herein, the terms “approximately” and “about” can be used interchangeably with the term “substantially” to denote an acceptable quality, value, or characteristic close to, but not necessarily exactly, that which is described or claimed. Thus, as used herein, the terms “approximately,” “about,” and “substantially” are used to describe acceptable quantities, values, or characteristics that are close to, but not necessarily exactly, that which is described or claimed. In at least some instances, the approximating language can correspond to the precision with which the instrument used to measure the value can distinguish the particular value from others.

[0237] Unless expressly indicated to the contrary, the articles "a" and "an" used in the specification and claims should be understood to include plural reference. A claim or description that includes "or" between one or more members of a group is considered to be satisfied if one, more than one, or all of the group members are present in, employed in, or otherwise related to a given product or process, unless otherwise indicated or obvious from the context. The present disclosure includes such embodiments in which exactly one member of the group is present in, employed in, or otherwise related to a given product or process. The present disclosure also includes embodiments in which more than one or all of the group members are present in, employed in, or otherwise related to a given product or process. Furthermore, it should be understood that the disclosed embodiments provide for all variations, combinations, and permutations in which one or more limitations, elements, clauses, descriptive terms, etc. from one or more of the listed claims are introduced into another claim (or any other claim that is related thereto) that is subordinate to the same base claim, unless otherwise indicated or unless a contradiction or inconsistency would be obvious to one of ordinary skill in the art. It is contemplated that all embodiments described herein apply to all different aspects of the disclosed embodiments, where appropriate. It is also contemplated that any embodiment or aspect can be freely combined with one or more other such embodiments or aspects, where appropriate. In the case where the elements are presented in the form of a list, for example, in a Markush group or similar format, it should be understood that each subgroup of the elements is also disclosed, and any element can be removed from the group. It should be understood that, in general, when the disclosed embodiments or the aspects of the disclosed embodiments are referred to as including specific elements, features, etc., some embodiments of the present disclosure or aspects of the present disclosure include or substantially include such elements, features, etc. For simplicity, these embodiments are not specifically described with so many words in each case. It should also be understood that any embodiment or aspect of the present disclosure can be explicitly excluded from the claims, regardless of whether specific exclusion is stated in the specification. For example, any one or more active agents, additives, ingredients, optional reagents, organism types, diseases, objects or combinations thereof can be excluded.

[0238] Where ranges are given herein, embodiments of the present disclosure include embodiments that include the endpoints, embodiments that exclude both endpoints, and embodiments that include one but not the other of the endpoints. Unless otherwise indicated, it is assumed that both endpoints are included. Further, it is to be understood that, unless otherwise specified or the context clearly dictates otherwise, in different embodiments of the present disclosure, a value indicated as a range can take on any particular value or sub-range within the range, up to one-tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise. It is also to be understood that where a series of numerical values are recited, embodiments of the present disclosure include embodiments that are similarly directed to any intervening value or range defined by any two values in the series, and that the lowest value can be considered a minimum value and the highest value can be considered a maximum value. As used herein, numerical values include values expressed in percentages.

[0239] While some variations have been described in detail above, other modifications or additions are possible.

[0240] In the descriptions above and in the claims, phrases such as “at least one of’ or “one or more of’ can occur followed by a conjunctive list of elements or features. The term “and / or” can also occur in a list of two or more elements or features. Unless otherwise implicitly or explicitly contradicted by the context in which it used, such a phrase is intended to mean any of the listed elements or features individually or any of the recited elements or features in combination with any of the other recited elements or features. For example, the phrases “at least one of A and B;” “one or more of A and B;” and “A and / or B” are each intended to mean “A alone, B alone, or A and B together.” A similar interpretation is also intended for lists including three or more items. For example, the phrases “at least one of A, B, and C;” “one or more of A, B, and C;” and “A, B, and / or C” are each intended to mean “A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together.” More generally, expressions such as “one of A, B, and C” or “one of A, B, and C, or any combination thereof” are intended to mean any of the individual elements A, B, and C, or any combination of the elements A, B, and C. Further, use of the term “based on” is intended to mean, and is used interchangeably with, the term “based at least in part on,” such that an item that is “based on” another item is not necessarily limited to being based only on that item.

[0241] The subject matter described herein can be implemented in systems, apparatus, methods, and / or articles depending on the desired configuration. The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and / or variations can be provided in addition to those set forth herein. For example, the implementations described above can be directed to various combinations and sub-combinations of the disclosed features and / or combinations and sub-combinations of several further features disclosed above. In addition, the logic flows depicted in the accompanying figures and / or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations can be within the scope of the following claims.

Claims

1. A system comprising: an electromagnetic radiation (EMR) source configured to generate an EMR beam; a beam shaper configured to collimate and shape the EMR beam into a transverse annular energy distribution, the beam shaper comprising a first axicon and a second axicon; an optical device configured to focus the EMR beam to a focal region within the tissue; a beam scanning system configured to scan the focal region within the tissue; A controller is configured to pulse-modulate the generated EMR beam with a plurality of pulses, wherein at least one pulse of the plurality of pulses has a pulse duration of approximately 100 microseconds or greater.

2. The system of claim 1, wherein the EMR beam has a wavelength in the range of approximately 1000 nm to approximately 12000 nm.

3. The system of claim 1, wherein the optical device is further configured to focus the EMR beam with a numerical aperture (NA) of at least about 0.

2.

4. The system of claim 1 , further comprising a window assembly located downstream of the optical device and configured to transmit the EMR beam when placed in contact with the outer surface of the tissue and configured to cool the tissue.

5. The system of claim 4, further comprising a cooler configured to cool the window assembly to a temperature in a range of about -20°C to about 20°C.

6. The system of claim 4, wherein the window component comprises: First window; a second window, separated from the first window; as well as A coolant chamber is disposed between the first window and the second window, the coolant chamber being configured to contain a coolant that does not substantially absorb the EMR beam.

7. The system of claim 4, wherein the controller is configured to control the electromagnetic radiation source to ensure that the window assembly cools the tissue to a predetermined temperature before generating the EMR beam.

8. The system of claim 4, wherein the controller is configured to control the electromagnetic radiation source to ensure that the window assembly cools the tissue for a predetermined period of time before generating the EMR beam.

9. The system of claim 1 , wherein the controller is configured to control one or more parameters of the EMR beam, the one or more parameters comprising: an inner diameter of the annular energy distribution, an outer diameter of the annular energy distribution, a thickness of the annular energy distribution, and a depth of the focal zone within the tissue.

10. A treatment method comprising: Cooling of tissues, generating an EMR beam using an electromagnetic radiation (EMR) source, the EMR beam having a wavelength within an effective range; collimating and shaping the generated EMR beam into a transverse annular energy distribution using a beam shaper comprising a first axicon and a second axicon; Using optical devices, focusing the collimated and shaped EMR beam to a focal area within the tissue; Scanning the focal area within the tissue using a beam scanning system; as well as Using a controller, the electromagnetic radiation source is controlled to pulse-modulate the EMR beam to have a plurality of pulses, wherein at least one pulse of the plurality of pulses has a pulse duration of approximately 100 microseconds or more. The method of claim 10 , wherein the wavelength is in the range of about 1000 nm to about 12000 nm.

12. The method of claim 10, further comprising cooling the window assembly to a temperature in a range of about -20°C to about 20°C.

13. The method of claim 10, wherein converging the EMR beam is performed with a numerical aperture (NA) of at least about 0.

2.

14. The method of claim 10, further comprising controlling the electromagnetic radiation source using the controller to ensure that the window assembly cools the tissue to a predetermined temperature prior to generating the EMR beam.

15. The method of claim 10, further comprising controlling the electromagnetic radiation source using the controller to ensure that the window assembly cools the tissue for a predetermined period of time before generating the EMR beam.

16. The method of claim 10, further comprising adjusting at least one parameter of the EMR beam, the at least one parameter comprising: an inner diameter of the annular energy distribution, an outer diameter of the annular energy distribution, a thickness of the annular energy distribution, and a depth of the focal zone within the tissue.

17. A system comprising: an electromagnetic radiation (EMR) source configured to generate an EMR beam having a desired wavelength; a beam shaper comprising a first axicon and a second axicon configured to collimate and shape the EMR beam into a transverse annular energy distribution, wherein the first axicon and the second axicon are separated by a separation distance along an optical axis; an optical device configured to focus the EMR beam to a focal region; a beam scanning system configured to scan the focal region; a window assembly located downstream of the optical device, the window assembly being configured to transmit the EMR beam and cool the tissue when placed in contact with an outer surface of the tissue The controller is configured as: controlling the electromagnetic radiation source to ensure that the window assembly cools the tissue to a predetermined temperature or for a predetermined time prior to generating the EMR beam; as well as controlling the electromagnetic radiation source to generate the EMR beam having a plurality of pulses, wherein at least one pulse of the plurality of pulses has a pulse duration of not less than 100 microseconds; and, wherein at least one of the electromagnetic radiation source, the optical device, and the beam scanning system is configured to control one or more parameters of the EMR beam, the one or more parameters comprising one or more of: an inner diameter of the annular energy distribution, an outer diameter of the annular energy distribution, a thickness of the annular energy distribution, and a depth of the focal region within the tissue.

18. A method for treating tissue, comprising: shaping a pulsed electromagnetic radiation (EMR) beam having an effective wavelength by a beam shaper including a first axicon and a second axicon to further have a transverse annular energy distribution; irradiating a tissue region with the pulsed EMR beam; focusing the pulsed EMR beam into a treatment region within the tissue region to create a treated tissue segment within the treatment region, the treated tissue segment comprising a spare, undamaged tissue region within a substantially annular region of damaged tissue, the treatment region being defined by a focus depth and a focus surface; as well as The pulsed EMR beam is scanned along a treatment path through at least a portion of the treatment region while varying at least one of the focus depth and the focus surface to create a plurality of treated tissue segments within the treatment region.

19. The method of claim 18, wherein the tissue region is a dermal region of a patient.

20. The method of claim 18, wherein the treated tissue segment extends through the epidermis of the dermal region and at least partially into the dermis of the tissue region.

21. The method of claim 18, wherein the wavelength is in a range between approximately 1000 nm and 12000 nm.

22. The method of claim 18, wherein the treated tissue segment has a substantially tapered shape extending into the tissue along the z-direction.

23. The method of claim 22, wherein the depth of the treated tissue segment is up to about 2000 microns.

24. The method of claim 18, further comprising varying at least one of the focal depth and the focal surface to change a shape of the treated tissue region.

25. The method of claim 18, wherein the treated tissue segment has a substantially circular horizontal cross-section.

26. The method of claim 18, wherein the treated tissue segment has a substantially Y-shaped vertical cross-section.

27. The method of claim 26, wherein the depth of the treated tissue segment is up to about 2000 microns.

28. A treatment method comprising: shaping the electromagnetic radiation beam to have a transverse annular energy distribution by a beam shaper comprising a first axicon and a second axicon; irradiating a first portion of the tissue region with a first pulse of the EMR beam to create a first micro-thermal zone; scanning the EMR beam to a second portion of the tissue region; as well as irradiating the second portion of the tissue region with a second pulse of the EMR beam to create a second micro-thermal zone, The first micro-hot zone and the second micro-hot zone each include a central undamaged area bounded by a peripheral damaged area.

29. The method of claim 28, further comprising focusing the EMR beam to a treatment depth within the tissue region prior to irradiating the first portion.

30. The method of claim 29, wherein the tissue region is a dermal region of a patient.

31. The method of claim 30, wherein the treated tissue segment extends through the epidermis of the dermal region and at least partially into the dermis of the tissue region.

32. The method of claim 31 , wherein the depth of the treated tissue segment is up to about 2000 microns.

33. The method of claim 28, wherein the first pulse and the second pulse deliver multiple energy levels at one or more treatment depths.

34. The method of claim 28, wherein the treated tissue segment has a substantially conical shape.

35. The method of claim 28, further comprising varying at least one of the depth of focus and the focusing surface to change the shape of the treated tissue region.

36. The method of claim 28, wherein the treated tissue segment has a substantially circular horizontal cross-section.

37. The method of claim 28, wherein the treated tissue segment has a substantially Y-shaped vertical cross-section.

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