Patent Application
20080269734
The invention relates generally to apparatus and methods for treating biological tissue using electromagnetic radiation. In particular, the invention relates to an optical array for treating biological tissue.
A port wine stain (PWS) is a congenital, progressive, vascular malformation of the dermis involving capillaries and possibly perivenular nerves. Port wine stains occur in approximately three out of one thousand live births. Although a PWS may be found anywhere on the body, they mostly appear on the face and are noted over the dermatome distribution of the first and second trigeminal nerves.
In early childhood, PWS are faint pink macules, but the lesions tend to darken progressively to red-purple and by middle age, often become raised as a result of the development of vascular papules or nodules and occasionally tumors. The hypertrophy of underlying bone and soft tissue occurs in approximately two-thirds of the patients with PWS, and serves to further disfigure the facial features of many children.
Prior art treatments for PWS include scalpel surgery, ionizing radiation, skin grafting, dermabrasion, cryosurgery, tattooing, electrotherapy and flashlamp-pumped pulsed dye lasers. Light passing through the epidermis is preferentially absorbed by hemoglobin which is the major chromophore in blood in the ectatic capillaries in the upper dermis. The radiant energy is converted to heat causing thermal damage and thrombosis in the targeted vessels. Some studies have shown that the flashlamp-pumped pulsed dye laser produce good results in many pediatric and adult patients. However, laser treatments of PWS face the challenge that the overlying epidermal pigment layer comprises a barrier or an optical shield through which the light must first pass to reach the underlying PWS blood vessels. The absorption of laser energy by melanin causes localized heating in the epidermis and reduces the light dosage reaching the blood vessels, thereby decreasing the amount of heat produced in the targeted port wine stains and leading to suboptimal blanching of the lesion and/or unwanted thermal injury to the epidermis.
The invention, in various embodiments, provides methods and apparatus for treating biological tissue. The biological tissue can be, but is not limited to, skin and hypodermal features such as port wine stains. The methods and apparatus can be for skin rejuvination. Apparatuses can include an array of needles to penetrate the biological tissue and fiber optics to deliver electromagnetic radiation to a subsurface volume of the biological tissue to treat the biological tissue. Advantages include effective and uniform treatment of deeper or selected layers of biological tissue without nonspecific damage to the upper or nonselected layers.
By applying electromagnetic radiation to subcutaneous tissue through a minimally invasive array of needles, the epidermis and the dermis can be spared from injury by the electromagnetic radiation. Furthermore, the electromagnetic radiation can diffuse within the subcutaneous tissue to effect a homogeneous treatment. Lower powers can also be used because the electromagnetic radiation is delivered directly to the targeted tissue and does not need to travel through the epidermis and/or dermis to reach the targeted tissue. At least a portion of the subcutaneous tissue can be treated for a PWS, and/or fibrosis and/or tightening of the skin can result without scarring the epidermis and/or dermis. Additionally, a portion of tissue can be suctioned or otherwise removed to facilitate treatment and/or mitigate the side effects of treatment.
In one aspect, the invention features a method for treating skin. The method includes penetrating an epidermis of the skin with a plurality of waveguides, each waveguide having an end. The method also includes positioning each end within a dermis of the skin, the dermis having a port wine stain. Additionally, the method includes delivering electromagnetic radiation through the plurality of waveguides to the dermis having the port wine stain for a time sufficient to selectively destroy a cutaneous blood vessel within the port wine stain. The time is less than a thermal diffusion time between the epidermis and the dermis to prevent forming substantial unwanted thermal injury within the epidermis.
In another aspect, the invention features a method for treating skin. The method includes penetrating a surface of a target region of the skin with a plurality of waveguides, each waveguide having an end. The method also includes positioning each end within the target region of the skin. Additionally, the method includes delivering electromagnetic radiation through the plurality of waveguides to the target region of skin to affect (i) at least one pigmentary abnormality disposed in an epidermal region of the target region and (ii) at least one vascular abnormality disposed in a dermal region of the target region.
In still another aspect, the invention features an apparatus for treating skin. The apparatus includes a first plurality of waveguides, each first waveguide having a first end, the first plurality of waveguides adapted for penetrating an epidermis of the skin, positioning each first end at about a first depth within the skin, and delivering electromagnetic radiation through the first plurality of waveguides to form a plurality of first injuries about the first depth. The apparatus also includes a second plurality of waveguides, each second waveguide having a second end, the second plurality of waveguides adapted for penetrating the epidermis, positioning each second end at about a second depth within the skin, and delivering electromagnetic radiation through the second plurality of waveguides to form a plurality of second injuries about the second depth.
In yet another aspect, the invention features a method for treating skin. The method includes penetrating an epidermis of the skin with a first plurality of waveguides, each first waveguide having a first end, and a second plurality of waveguides, each second waveguide having a second end. The method also includes positioning each first end at about a first depth within the skin and each second end at about a second depth within the skin. Additionally, the method includes delivering electromagnetic radiation through the first plurality of waveguides to form a plurality of first injuries about the first depth and delivering electromagnetic radiation through the second plurality of waveguides to form a plurality of second injuries about the second depth.
In still yet another aspect, the invention features a method for treating skin. The method includes penetrating an epidermis of the skin with a plurality of waveguides, each waveguide having an end. The method also includes positioning each end at about a first depth within the skin and delivering electromagnetic radiation through the plurality of waveguides to form a plurality of first injuries about the first depth. Additionally, the method includes positioning each end at about a second depth within the skin and delivering electromagnetic radiation through the second plurality of waveguides to form a plurality of second injuries about the second depth.
In other examples, any of the aspects above, or any apparatus or method described herein, can include one or more of the following features.
In various embodiments, the methods include delivering the electromagnetic radiation substantially simultaneously to multiple depths within the dermis. The methods can include delivering the electromagnetic radiation while the plurality of waveguides are being positioned within the dermis to treat multiple depths within the dermis. The methods can also include delivering electromagnetic radiation while the plurality of waveguides are being removed from the dermis to treat multiple depths within the dermis.
In some embodiments, the methods include positioning each end at multiple depths within the dermis of the skin and delivering electromagnetic radiation through the plurality of waveguides to the multiple depths within the dermis, to treat multiple layers or strata of the port wine stain. The methods can include delivering the electromagnetic radiation substantially simultaneously to the at least one pigmentary abnormality and the at least one vascular abnormality. The methods can also include cooling a surface of the epidermal region of the target region of skin to prevent substantial unwanted injury to at least a portion of the epidermal region.
In certain embodiments, the methods include positioning each end within the target region of the skin at a first depth to treat the at least one vascular abnormality, and repositioning each end within the target region of the skin at a second depth to treat the at least one pigmentary abnormality.
In various embodiments, the plurality of first injuries or the plurality of second injuries comprise a volume of necrotic thermal injury. The plurality of first injuries or the plurality of second injuries can partially denature collagen to cause the skin to rejuvenate. The plurality of first injuries or the plurality of second injuries can accelerate collagen synthesis in the skin to cause the skin to rejuvenate. The plurality of first injuries or the plurality of second injuries can elicit a healing response that produces substantially unwrinkled skin. The plurality of first injuries or the plurality of second injuries can activate fibroblasts which deposit increased amounts of extracellular matrix constituents in the skin.
In some embodiments, the plurality of first injuries or the plurality of second injuries are intervened by substantially undamaged skin. The methods can include forming a plurality of noncontiguous second injuries, disposed relative to the plurality of first injuries, to form a pattern of interspersed first injuries and second injuries. The plurality of first injuries can be shallower than the plurality of second injuries.
In certain embodiments, the electromagnetic radiation delivered to the first depth and the electromagnetic radiation delivered to the second depth differ in at least one parameter. The parameter can include at least one of fluence, wavelength, or pulse duration.
Other aspects and advantages of the invention will become apparent from the following drawings and description, all of which illustrate principles of the invention, by way of example only.
The advantages of the invention described above, together with further advantages, may be better understood by referring to the following description taken in conjunction with the accompanying drawings. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.
A plurality of waveguides formed in an array pattern can be inserted into biological tissue. The waveguides can be positioned in the tissue so that a subsurface volume of the biological tissue can be treated. Electromagnetic radiation is delivered using the waveguides to treat the subsurface volume.
In certain embodiments, a treatment can be for one or more of the following indications: acne, erythema, fat, cellulite, oily skin, pigmented lesions, pores, scarring, vascular lesions (including port wine stains), pigmented lesions, and wrinkles, as well as for skin rejuvenation, hair removal, and hair regrowth. Target chromophores can include water, fat, collagen, blood or a blood component, melanin, or other commonly targeted skin chromophores in cosmetic and dermatologic treatments. Vascular lesions, such as PWS, telangiectasia and hemangiomas, are characterized by abnormally enlarged blood vessels. Pigmented lesions are non-vascular disfigurements of the skin caused by an abnormally high concentration of melanin in localized areas of the skin. Such pigmented lesions include freckles, age or liver spots, cafe au lait birthmarks, lentigines, nevi, melanomes, nevus of Ota and lentigo maligna.
In various embodiments, each needle 110 is adapted for penetrating biological tissue to a depth of about 0.5 mm to about 30 mm from a surface of the biological tissue. A needle 110 can be adapted to penetrate biological tissue to a depth of about 0.5 cm to about 2 cm. In certain embodiments, a needle 110 can be adapted to penetrate biological tissue to a depth of up to about 1 cm or about 2 cm. Indications such as PWS can extend even deeper within the skin and, in different embodiments, the needle 110 can be adapted to penetrate the biological tissue to any depth necessary to treat the indication. The diameter of each needle can be between about 0.2 mm and about 2 mm. In one embodiment, the diameter of each needle 110 is less than about 1 millimeter. In various embodiments, each needle 110 can be a different diameter and/or length. This can result in each needle 110 being positioned at a different depth within the subsurface volume of biological tissue, and can facilitate treatment at more than one depth. Variations in needle 110 length can also facilitate simultaneously treatment of a larger volume of biological tissue. Each needle 110 can be disposable. The base member 105 can be disposable. In one embodiment, the base member 105 and plurality of needles 110 can be a disposable, and/or can be a cartridge. Alternatively, the plurality of needles 110 and/or base member 105 can be sterilized and reusable. Each needle 110 can include stainless steel or aluminum, and can be a 30 G needle or a 27 G needle. In one embodiment, the needle 110 can be a STERIJECT® Rimos or Mesoram needle, which can be used as a multiinjector for mesotherapy.
The plurality of needles 110 form an array capable of penetrating a biological tissue and positioning each end 125 within a subsurface volume of the biological tissue. The base member 105 can function as a depth gauge by limiting the depth to which a needle 110 can be inserted into the biological tissue. The base member 105 and the needle 110 can be adjustable, so that the length of the needle 110 extending from the base member 105 can be adjusted. In one embodiment, the array of needles 110 are passed through holes in a rigid frame or a base member 105 and epoxied or fused to the frame or a base member 105. A biocompatible epoxy or low temperature glass frit can be used to epoxy or fuse the needles 110. Each fiber optic 115 is adapted for insertion into the bore 120 of each needle 110, and each fiber optic 115 is capable of delivering electromagnetic radiation to the subsurface volume of the biological tissue to treat the biological tissue.
In various embodiments, the invention can include additional features to facilitate treatment of the biological tissue. For example, the apparatus can include a means for suctioning at least a portion of the biological tissue. The means of suctioning can be a needle 110 and a vacuum, or can be a different type of needle or tube, to remove and/or drain at least a portion of the subsurface volume of biological tissue.
The invention is not limited to the number and/or arrangement of needles shown in
In various embodiments, the base member and/or needle array can have a diameter of about 10 cm, or dimensions up to about 10 by 10 cm, 5 by 5 cm, or 5 by 10 cm. The base member and/or needle array can be square, rectangular, circular, ovoid, or polygonal. Polygonal or other base members can be used for “tiling,” to cover a larger area by forming a regular pattern of individual treatment areas. In various embodiments individual needles can be spaced less than about 5 mm apart or between about 50 microns to about 2 mm apart. In some embodiments, individual needles can be spaced between about 500 microns to about 1 mm apart. In certain embodiments, needles are spaced about 0.5 mm or about 1 mm apart. The spacing between needles in an array need not be uniform, and can be closer in areas where a greater amount of damage or more precise control of damage in the target area of tissue is desired. In one embodiment, the array of needles can include pairs of needles separated from adjacent pairs by larger distances. Needles can be arranged in a regular or near-regular square, triangular, or other geometrical arrays. The pattern of damage and/or tissue reshaping can be controlled by adjusting the intensity and/or duration of power transmitted to individual fiber optics. An array of needles can distribute pressure over a larger area when puncturing the skin, to reduce pain and/or discomfort.
The invention is not limited to the number and/or arrangement of fiber optics shown in
A fiber optic system can include a control system that can control the fiber optics individually. In one embodiment, the control system can deliver electromagnetic radiation to a subset of the fiber optics. The subset of fiber optics can match a pattern of a target, to treat the target and spare surrounding tissue. For example, the target can be a vein and the controller can deliver electromagnetic radiation to curvilinear array of fiber optics to treat the vein and to spare the tissue surrounding the vein. The control system can control the properties of electromagnetic radiation delivered to each fiber optic. For example, the fluence, wavelength, and/or duration of the electromagnetic radiation delivered to each fiber optic can be controlled.
In various embodiments, tissue in the target region can be heated to a temperature of between about 50° C. and about 100° C., although higher and lower temperatures can be used depending on the application. In one embodiment, the temperature is between about 55° C. and about 70° C. In one embodiment, the temperature is between about 70° C. and about 100° C.
In various embodiments, the beam of electromagnetic radiation can have a wavelength between about 400 nanometers and about 10,600 nanometers. The beam of radiation can have a wavelength between about 330 and about 600 nm, about 585 nm and about 600 nm, or between about 700 and about 800 nm. In some embodiments, the beam of radiation has a wavelength of about 500 nm, 532 nm, 585 nm, 595 nm, 755 nm, 780 nm, 1210 nm, or 1310 nm. The source of the beam of radiation can be an alexandrite laser, a variable pulsed duration alexandrite laser, a Nd:Yag laser, a diode laser, or a flashlamp pumped pulsed dye laser. The beam of radiation can have a wavelength that is absorbed by endogenous cutanious chromophores including hemoglobin, melanin, and/or other chromophores within the PWS or lesion.
In various embodiments, the beam of radiation can have a fluence up to about 500 J/cm2. In one embodiment, the beam of radiation has a fluence of between about 60 J/cm2 and about 300 J/cm2, although higher and lower fluences can be used depending on the application. In one embodiment, the beam of radiation has a fluence between about 1 and 10 J/cm2 and preferably between 2 and 4 J/cm2. In another embodiment, the beam of radiation has a fluence of between about 60 J/cm2 and about 150 J/cm2. In one embodiment, the beam of radiation has a fluence between about 80 J/cm2 and about 100 J/cm2. High fluences can lead to better collagen shrinkage in a blood vessel wall and/or perivascular, and therefore better stenosis. Lower fluences can be appropriate in many embodiments because direct delivery of light to about the region of skin to be treated through a waveguide, as apposed to transmission through the epidermis and/or dermis, can mitigate the fluence necessary to effect treatment.
In various embodiments, the beam of radiation can have a pulse duration between about 10 ms and about 300 ms, although a longer and shorter pulse duration can be used depending on the application. In one embodiment, the beam of radiation has a pulse duration between about 20 ms and about 100 ms. In one embodiment, the beam of radiation has a pulse duration between about 20 ms and about 60 ms. In one embodiment, the beam of radiation has a pulse duration between about 20 ms and about 40 ms. In one embodiment, the beam of radiation has a pulse duration between about 40 ms and about 60 ms. In one embodiment, the beam of radiation has a pulse duration of about 40 ms. In one embodiment, the beam of radiation has a pulse duration greater than about 40 ms. In one embodiment, the beam of radiation has a pulse duration of less than 1 μs, and preferably less than 500 ns.
In various embodiments, the beam of radiation can be delivered at a rate of between about 0.1 pulse per second and about 10 pulses per second, although faster and slower pulse rates can be used depending on the application.
In various embodiments, the parameters of the radiation can be selected to deliver the beam of radiation to a predetermined depth. In some embodiments, the beam of radiation can be delivered to the target area up to about 10 mm below a surface of the skin although shallower or deeper depths can be selected depending on the application. In some embodiments, the beam of radiation can be delivered to the target area up to about 5 mm below a surface of the skin. In some embodiments, the beam of radiation can be delivered to the target area up to about 4 mm below a surface of the skin. In some embodiments, the beam of radiation can be delivered to the target area up to about 2 mm below a surface of the skin. In some embodiments, the beam of radiation can be delivered to the target area up to about 1 mm below a surface of the skin.
A cooling system can be used to modulate the temperature in a region of biological tissue and/or minimize unwanted thermal injury to untargeted region of biological tissue. For example, the system can cool the skin before, during, or after delivery of radiation, or a combination of the aforementioned. Cooling can include contact conduction cooling, evaporative spray cooling, convective air flow cooling, or a combination of the aforementioned. In one embodiment, the handpiece includes a skin contacting portion that can be brought into contact with a region of skin. The base member can be cooled. A cooling plate can also be cooled. The cooling pale can be adjacent the base member. The cooling pale can define a plurality of holes through which the needles can pass. By cooling only a region of the target region or by cooling different regions of the target region to different extents, the degree of thermal injury of regions of the target region can be controlled.
U.S. patent application Ser. No. 11/645,222 and U.S. Pat. Nos. 5,312,395, 5,599,342, and 5,814,040, the disclosures of which are incorporated by reference herein in their entirety, disclose treatment parameters and features that can be advantageously employed with the invention.
In various embodiments, local anesthesia can be administered to the patient. Anesthesia can be delivered prior to and/or during delivering the beam of radiation or penetrating the biological tissue. In one embodiment, the anesthesia can be injected directly into the biological tissue. Anesthesia delivery can also include applying a topical anesthetic to the biological tissue. Alternatively, the method can include the use of general anesthesia. Performing the procedure without anesthesia can be beneficial for patients who may have an adverse reaction to anesthesia. Use of local anesthetic can also reduce cost of a procedure by eliminating the need for an anesthesiologist.
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The electromagnetic radiation 675 can thermally injure at least a portion of the PWS blood vessels 625 and/or surrounding tissue. The method can include allowing the thermally injured PWS blood vessels and/or surrounding tissue to escape through the needle holes. The method can also include suctioning the thermally injured PWS blood vessels and/or surrounding tissue through the plurality of needles 110 and/or another means for suctioning. In some embodiments, the needle is partially retracted to expose at least a portion of the fiber optics 115 to the PWS blood vessels 625 and/or surrounding tissue. The electromagnetic radiation 675 can also be delivered through one or more openings defined by the needle 110.
In various embodiments, the method can include the additional steps of (i) removing each end 125 from the dermis 615; (ii) translating and/or rotating the plurality of needles 110 relative to the biological tissue; (iii) penetrating the surface 605 of the of biological tissue with the plurality of needles 310; (iv) positioning the each end 125 within a second subsurface volume (not shown) of the dermis 615; and (v) delivering electromagnetic radiation 675 through each fiber optic 115 inserted within the bore to the second subsurface volume of the biological tissue to treat the biological tissue. Translating or rotating the plurality of needles 110 relative to the biological tissue can form a larger area of coverage (e.g., positioning the each end 125 within a second subsurface volume) and/or higher coverage of a single area (e.g., repositioning each end 125 within a portion of the subsurface volume that was already treated).
In some embodiments, the method can include moving a portion of the at least one fiber optic within the subsurface volume of biological tissue while delivering electromagnetic radiation. For example, the plurality of needles 310 can be moved within the dermis 615 while delivering electromagnetic radiation 675 to maximize the amount of the PWS blood vessels 625 that are thermally injured. The melted and/or liquefied PWS blood vessels 625 can drain through the needle holes and/or be removed by suctioning. Suctioning can include removing the fiber optic 115 from at least a portion of the bore 120 and applying a vacuum 310. In various embodiments massage and/or irrigation can be employed to aid in the removal of melted and/or liquefied PWS blood vessels 625. In another example, blood within the PWS blood vessels 625 can be drained through the needle holes and/or be removed by suctioning prior to the delivery of the electromagnetic radiation 675. Drainage or removal of the blood can improve treatment of the PWS by at least one of facilitating collapse of the PWS blood vessels 625, reducing the volume of tissue to be thermally injured, and increasing the thermal injury to the PWS blood vessels 625 (e.g., more light is absorbed by the PWS blood vessels 625 in the absence or reduced presence of blood). In certain embodiments, the method can include mitigating pain and/or discomfort. For example, anesthesia can be administered before step 600 when the plurality of needles 110 penetrates the surface 605 of the biological tissue or after step 600. Anesthesia can also be administered during the treatment.
In various embodiments, the method can include cooling at least a portion of the biological tissue, to mitigate undesired thermal damage to the portion of the biological tissue. For example, the epidermis and/or dermis can be cooled in conjunction with delivering increased fluences of electromagnetic radiation to the subcutaneous tissue to mitigate undesired thermal damage to the epidermis and/or dermis while increasing the efficacy of treatment of the subcutaneous tissue. A member can apply pressure to and/or cool the skin, to displace blood from a region of biological tissue, to limit damage to blood vessels in the region of biological tissue.
In one embodiment, the method includes contacting the skin with a cooled plate to cool and numb the skin. The plate can define a plurality of holes. A plurality of needles 110 can penetrate the surface 605 of the biological tissue through the plurality of holes in the plate. Alternatively, the plate can be removed before the plurality of needles 110 penetrate the surface 605 of the biological tissue.
The treatment radiation can damage and/or destroy one or more PWS blood vessel cells so that at least a portion of the damaged cells can escape and/or can be drained from the treated region. At least a portion of the damaged cells can be carried away from the tissue through a biological process. In one embodiment, the body's lymphatic system can drain the damaged and/or destroyed cells from the treated region. In an embodiment where a cell is damaged, the cell can be viable after treatment. In one embodiment, a first portion of the fat cells is damaged and a second portion is destroyed. In one embodiment, a portion of the damaged and/or destroyed cells can be removed to selectively change the shape of the body region.
In some embodiments, the beam of radiation can be delivered to a target chromophore in the target region. Suitable target chromophores include, but are not limited to, water, collagen, fat, melanin, and hemoglobin. The energy absorbed by the chromophore can be transferred to the cell to damage or destroy the cell. For example, thermal energy absorbed by dermal tissue can be transferred to the PWS. In one embodiment, the beam of radiation is delivered to water within or in the vicinity of a PWS in the target region to thermally injure the PWS.
In various embodiments, treatment radiation can affect one or more cells and can cause sufficient thermal injury in the dermal region of the skin to elicit a healing response to cause the skin to remodel itself. This can result in more youthful looking skin. In one embodiment, sufficient thermal injury induces fibrosis of the dermal layer, fibrosis on a subcutaneous region, or fibrosis in or proximate to the dermal interface. In one embodiment, the treatment radiation can partially denature collagen fibers in the target region. Partially denaturing collagen in the dermis can induce and/or accelerate collagen synthesis by fibroblasts. For example, causing selective thermal injury to the dermis can activate fibroblasts, which can deposit increased amounts of extracellular matrix constituents (e.g., collagen and glycosaminoglycans) that can, at least partially, rejuvenate the skin. The thermal injury caused by the radiation can be mild and only sufficient to elicit a healing response and cause the fibroblasts to produce new collagen. Excessive denaturation of collagen in the dermis causes prolonged edema, erythema, and potentially scarring. Inducing collagen formation in the target region can change and/or improve the appearance of the skin of the target region, as well as thicken the skin, tighten the skin, improve skin laxity, and/or reduce discoloration of the skin.
In one embodiment, fatty tissue is heated by absorption of radiation, and heat can be conducted into dermal tissue proximate the fatty tissue. The fatty tissue can be disposed in the dermal tissue and/or can be disposed proximate to the dermal interface. A portion of the dermal tissue (e.g., collagen) can be partially denatured or can suffer another form of thermal injury, and the dermal tissue can be thickened and/or be strengthened as a result of the resulting healing process. In such an embodiment, a fat-selective wavelength of radiation can be used.
In one embodiment, collagen and/or water in the dermal tissue is heated by absorption of radiation. For example, in various embodiments, the radiation can have a wavelength of about 400 nm to about 2,600 nm, or about 1.3 microns to about 1.8 microns, which can target water and/or collagen absorption peaks. The dermal tissue can have disposed therein fatty tissue and/or can be overlying fatty tissue. A portion of the dermal tissue (e.g., collagen) can be partially denatured or can suffer another form of thermal injury, and the dermal tissue can be thickened and/or be strengthened as a result of the resulting healing process. A portion of the heat can be transferred to the fatty tissue, which can be affected. In one embodiment, water in the fatty tissue absorbs radiation directly and the tissue is affected by heat. In such embodiments, a water selective wavelength of radiation can be used.
In various embodiments, the invention can include photodynamic therapy (PDT). For example, a photosensitizer (e.g., aminolevulinic acid, ALA, or methyl aminolevulinate) can be administered to the subject, and the light can be delivered directly to the desired treatment site using a plurality of waveguides at virtually any location. Thus, the invention can include PDT treatments that are not limited by the transmission of light through the skin or biological tissue. The invention can also include treatments that deliver virtually any wavelength of light to activate the photosensitizer while reducing collateral damage. For example, longer wavelengths such as 630 nm are often used for PDT because shorter wavelengths are strongly absorbed by the melanin and cause collateral damage. However, shorter wavelengths can be more effective in activating photosensitizers like ALA. Thus the method can include a PDT treatment delivering blue light (e.g., about 400 nm) through a waveguide directly to a PWS, to increase photosensitizer activation and reduce collateral damage. In addition to PWS, the invention can include PDT for fatty tissue, cancerous tissue, and other tissue. For example, a lipid-soluble photosensitizer (e.g., hypericin, an extended quinone photosensitizer produced by St. John's wort) can be used to enhance the treatment, melting, removal, and thermal injury of fatty tissue. In other examples, the invention can include PDT for cancers including basal cell carcinoma and other skin cancers, sebaceous tumors, eccrine and apocrine tumors, lipomas, and generally any localized, protruding, or bulky tumor.
U.S. Pat. Nos. 5,810,801, 6,120,497, and 6,659,999 and U.S. patent application Ser. Nos. 10/241,273, 10/407,921, 10/698,970 and 11/148,051, the disclosures of which are incorporated by reference herein in their entirety, disclose treatment parameters and features that can be advantageously employed with the invention.
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In various embodiments, a step like step 800 and/or 900 can include the simultaneous delivery of electromagnetic radiation 675 through the plurality of fiber optics 115 to at least two of the surface 605, the epidermis 610, the dermis 615, and the subcutaneous tissue 620 to treat the biological tissue. In some embodiments, a step like step 800 and/or 900 can include the delivery of electromagnetic radiation 675 through the plurality of fiber optics 115 to at least multiple depths within the surface 605, the epidermis 610, the dermis 615, and/or the subcutaneous tissue 620 to treat the biological tissue. In certain embodiments, such as step 800 and/or 900, the electromagnetic radiation is delivered approximately perpendicular to the axis of the needle 110. In one embodiment, the needles are spaced such that the electromagnetic radiation forms zones of thermal injury separated by substantially undamaged biological tissue.
The methods shown in
The first thermal injuries 1020 can be more severe than the second thermal injuries 1025. For example, the first thermal injuries 1020 can be necrotic thermal injuries within the epidermis, and the second thermal injuries 1025 can denature collagen within the dermis. Necrotic thermal injuries elicit a healing response from the skin. Denaturing collagen can accelerate collagen synthesis, tighten skin, mitigate wrinkles, and/or elicit a healing response. An interspersed plurality of first thermal injuries 1020 and second thermal injuries 1025 can intensify the skin's healing response and accelerate recovery and healing, as compared to a large, continuous thermal injury. Healing can initiate from less injured or substantially undamaged skin 1030 adjacent the plurality of first thermal injuries 1020 and/or second thermal injuries 1025.
The first thermal injuries 1120 can be more severe than the second thermal injury 1125. For example, the first thermal injuries 1120 can be necrotic thermal injuries within the epidermis and the second thermal injury 1125 can denature collagen within the dermis. Necrotic thermal injuries elicit a healing response from the skin. Denaturing collagen can accelerate collagen synthesis, tighten skin, mitigate wrinkles, and/or elicit a healing response. The first thermal injuries 1120 overlying a second thermal injury 1125 can intensify the skin's healing response and accelerate recovery and healing, as compared to a large, continuous, severe thermal injury. Healing can initiate from less injured or substantially undamaged skin 1130 adjacent the plurality of first thermal injuries 1120 and/or second thermal injury 1125.
In various embodiments, methods such as those illustrated in
In some embodiments, the biological tissue can be covered with an absorbent material to draw one or more fluids from the biological tissue. The absorbent material can be a wound dressing that includes a substance to draw fluid from the biological tissue to increase the biological tissue's response to the injury, remove unwanted or damaged biological tissue, and/or to induce shrinkage of the biological tissue.
Skin shrinkage can result in an improvement in the skin's appearance. For example, puncturing and treating the skin with radiation can damage or destroy selected tissue, and can elicit a healing response to cause the skin to remodel itself. Skin shrinkage can thicken the skin, tighten the skin, improve skin laxity, induce collagen formation, promote fibrosis of the dermal layer, and result in rejuvenation of the skin. In certain embodiments, improvement occurs in the dermal region of the skin. Furthermore, a treatment can include a series of treatment cycles, so that skin can be reduced gradually, and/or the skin can be tightened gradually, resulting in a more cosmetically appealing appearance.
The skin can shrink by a range of a factor of about 1 to about 10. In certain embodiments, the skin can shrink by at least a factor of about 1.25 to about 5. In some embodiments, the skin can shrink by at least a factor of about 1.1, 2, 3, or 4. Skin shrinkage can be measured by determining the percentage decrease in a volume of target tissue. Skin shrinkage can be measured by determining the percentage decrease in the surface area of the target tissue.
The absorbent material 1305 can draw fluid from the skin. The fluid can be one or more of a body fluid, a cellular fluid, damaged tissue, injured tissue, melted tissue, liquefied tissue, and water. The absorbent material 1305 can include a solid or a liquid. The absorbent material 1305 can include salt or glycerol. For example, the absorbent material 1305 can include at least one of a salt mixture or a composition including a salt. The absorbent material 1305 can be a desiccating agent, a solution adapted to draw a body fluid from the target region, or a solution adapted to draw a cellular fluid from the target region. The absorbent material can include an antiseptic, an antibiotic, and/or a disinfectant.
The absorbent pad 1300 or the absorbent material 1305 can cause the fluid to migrate from the target region of skin to the absorbent material 1305. For example, the fluid can migrate to an outer surface of the skin so the absorbent material 1305 can absorb the fluid.
The severity of the treatment can be varied, for example, by varying the density of skin punctures, the size of the needles, the depth of the punctures, and by varying the concentration of the topical agents used. More aggressive treatment may lead to beneficial skin shrinkage with a scar. Less aggressive treatments may produce beneficial skin shrinkage without producing a scar.
In certain embodiments, the absorbent material 1305 can be applied directly to the skin 1405. A bandage, e.g., the absorbent pad 1300, can be applied over the skin 1405 and the absorbent material 1305.
In certain embodiments, suction can be used to remove fluid from the biological tissue. For example, as the needles are removed from the biological tissue, the force of withdraw can draw fluid to the surface of the biological tissue. In some embodiment, a suction system or syringe is used.
In certain embodiments, the biological tissue can be irrigated after the biological tissue is punctured. This can include using a needle or syringe to inject a fluid into the biological tissue.
In certain embodiments, a beam of radiation can be applied through the surface of the biological tissue to affect the biological tissue. The beam of radiation can augment or complement the treatment using the waveguides or needles. The beam of radiation can be applied before, during, or after insertion of the waveguides or needles. For example, the beam of radiation can be delivered to the target region to thermally injure, damage, and/or destroy one or more fat cells. This can lead to reshaping of the biological tissue region as the skin size is reduced. The surface of the biological tissue can be cooled to protect overlying tissue.
In some embodiments, the beam of radiation can cause sufficient thermal injury in the dermal region of the skin to elicit a healing response to cause the skin to remodel itself. This can result in more youthful looking skin. In one embodiment, sufficient thermal injury induces fibrosis of the dermal layer, fibrosis on a subcutaneous fat region, or fibrosis in or proximate to the dermal interface. In one embodiment, the treatment radiation can partially denature collagen fibers in the target region. Partially denaturing collagen in the dermis can induce and/or accelerate collagen synthesis by fibroblasts. For example, causing selective thermal injury to the dermis can activate fibroblasts, which can deposit increased amounts of extracellular matrix constituents (e.g., collagen and glycosaminoglycans) that can, at least partially, rejuvenate the skin. The thermal injury caused by the radiation can be mild and only sufficient to elicit a healing response and cause the fibroblasts to produce new collagen. Excessive denaturation of collagen in the dermis causes prolonged edema, erythema, and potentially scarring. Inducing collagen formation in the target region can change and/or improve the appearance of the skin of the target region, as well as thicken the skin, tighten the skin, improve skin laxity, and/or reduce discoloration of the skin.
While the invention has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention as defined by the appended claims.
This application is a continuation in part of U.S. patent application Ser. No. 11/796,146 filed Apr. 26, 2007, which is owned by the assignee of the instant application and the disclosure of which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11796146 | Apr 2007 | US |
| Child | 11757028 | US |
