Patent Description:
This application is also related to co-filed, co-pending and co-assigned PCT Patent Application titled "METHODS AND DEVICES FOR THERMAL SURGICAL VAPORIZATION AND INCISION OF TISSUE".

The present invention, in some embodiments thereof, relates to surgical methods and devices, and, more particularly, but not exclusively, to methods and devices for vaporization of tissue and even more particularly, but not exclusively, to methods and devices for production of arrays of micro depressions in skin.

Various techniques are known to perform tissue ablation, commonly involving the use of a pulsed laser or RF energy.

CO<NUM> as well as Erbium lasers are widely utilized in fractional skin resurfacing. They vaporize craters in tissue by a cell explosion effect which removes both stratum cornea as well as epidermal tissue.

Current methods of fractional skin rejuvenation include non ablative treatments. This is performed with infrared optical sources such as Erbium glass lasers operating at <NUM> micron wavelength which penetrate deep into tissue (~ <NUM>, deeper than the papillary dermis (~<NUM> micron) depth, or infrared lamps equipped with an array of focusing micro-lenses. Such treatment devices are produced by Palomar Medical for example. In such cases the skin surface typically remains intact while deeper skin layers are heated and thermally injured. The injury level in the epidermis as well as in the papillary dermis with such lasers or infrared sources is much lower than injury level produced by ablative lasers such as CO2 or Erbium lasers. The current non ablative treatments have an advantage of immediate return to work since skin surface appears intact. A disadvantage is the milder clinical effect on fine wrinkles and skin texture.

Skin permeability to a large variety of drugs, creams and other substances is known to be low due to stratum cornea skin protection features. The increase of skin permeability by vaporization or highly damaging the stratum cornea layer of the skin without damaging the epidermis is described and explained in below-mentioned <CIT> as well as in below-mentioned article by Prausnitz. As described by Prausnitz, stratum cornea permeability to most drugs increases dramatically when attaining a temperature of <NUM> deg C. Thermal coagulation or denaturation of epidermal collagen and other proteins reduces the permeability enhancement by orders of magnitude.

Published <CIT> discloses a device for vaporizing a hole in tissue, including a vaporizing element, a heating element, configured to heat the vaporizing element, and a mechanism configured to advance the vaporizing element into a specific depth in the tissue and retract the vaporizing element from the tissue within a period of time long enough for the vaporizing element to vaporize the tissue and short enough to limit diffusion of heat beyond a predetermined collateral damage distance from the hole.

European patent application <CIT> discloses a method of enhancing the permeability of the skin to an analytic for diagnostic purposes or to a drug for therapeutic purposes is described utilizing micro-pore and optionally sonic energy and a chemical enhancer. If selected, the sonic energy may be modulated by means of frequency modulation, amplitude modulation, phase modulation, and/or combinations thereof. Micro-pore is accomplished by (a) ablating the stratum corneum by localized rapid heating of water such that water is vaporized, thus eroding cells; (b) puncturing the stratum corneum which a micro-lancet calibrated to form a micro-pore of up to about <NUM> mu m in diameter; (c) ablating the stratum corneum by focusing a tightly focused beam of sonic energy onto the stratum corneum; (d) hydraulically puncturing the stratum corneum with a high-pressure jet of fluid to form a micro-pore of up to about <NUM> mu m in diameter; or (e) puncturing the stratum corneum with short pulses of electricity to form a micro-pore of up to about <NUM> mu m in diameter.

US published patent application number <CIT> discloses a tissue ablation system includes an elongated shaft, such as a surgical probe shaft, and an needle electrode array mounted to the distal end of the shaft, and an ablation source, such as, e.g., a radio frequency (RF) generator, for providing ablation energy to the electrode array. The tissue ablation system further includes a heat sink disposed within the distal end of the shaft in thermal communication with the needle electrode array. In this manner, thermal energy is drawn away from the needle electrode array, thereby cooling the electrode array and providing a more efficient ablation process. The tissue ablation system further comprises a coolant flow conduit in fluid communication with the heat sink, so that the thermal energy can be drawn away from the heat sink. In the preferred embodiment, the flow conduit includes a thermal exchange cavity in fluid communication with the heat sink, a cooling lumen for conveying a cooled medium (such as, e.g., saline at room temperature or below) to the thermal exchange cavity, and a return lumen for conveying a heated medium from the thermal exchange cavity. The tissue ablation system further comprises a pump assembly for conveying the cooled medium through the cooling lumen to the thermal exchange cavity at the distal end of the shaft.

Additional background art includes:
An article by <NPL>.

A text book chapter found on the World Wide Web at wwwf(dot)imperial(dot)ac(dot)uk/~ajm8/M3A10/lub(dot)pdf.

The present invention relates to devices for vaporization of tissue as defined in the appended independent claim <NUM>. The methods described here below are not part of the present invention.

An aspect of some embodiments of the invention involves using a tip of a heated rod or an array of tips of one or more heated rods, to produce a crater in skin. In some embodiments, the crater is produced in the epidermis while keeping a top layer of stratum corneum, which may cover the crater and potentially help prevent infection and assist healing. In some embodiments the stratum corneum is partly damaged, such that a ratio of remaining stratum corneum area to an area of a produced crater is optionally in a range of at least <NUM>% coverage, at least <NUM>% coverage, at least <NUM>% coverage, and even approximately <NUM>% coverage - the stratum corneum may be damaged yet still cover most of the crater's area.

The invention involves detecting when the tip(s) or array of tips comes in touch with skin, by detecting mechanical resistance of the tissue or skin to the tips pushing against it. Detecting when tip(s) come in touch with skin is meaningful when aiming for a specific depth and/or shape of the crater in the skin, since merely advancing tip(s) a specific distance beyond a plate (a distal gauge) placed upon the skin is likely to be inaccurate. It has been found that when placing a plate, which has openings for the tip(s) to go through, upon a skin, the skin may bulge into the openings, or otherwise not form a flat plane at the plate openings. A distance of advancement of a tip beyond the plate is not always equivalent to a depth of a crater formed in the skin. In order to control a depth of a crater formed in skin may be better done by detecting when the tip comes in touch with the skin and starts pushing against it.

An aspect of some embodiments of the invention includes measuring a speed of advancement of the tip(s), and detecting when the tip(s) movement is slowed by the skin.

An aspect not according to the invention involves manufacturing an array of tips such as mentioned above, coated with a biocompatible coating, suitable for withstanding high temperatures used for treatment, optionally withstanding even higher temperature which in some cases may be used to clean a used tip array by oxidizing residues and/or sterilizing.

Some examples are related to a thermal skin crushing element, such as a crushing rod, adapted to supply an amount of heat in a short amount of time to crush tissue or create a crater or depression while avoiding damage below the papillary dermis. The depression produced potentially remains depressed for a period of time, for example for half a day, a day, or a few days.

According to an aspect of some embodiments of the present invention there is provided an array of sharp tips for treating tissue including a plurality of sharp tips having a biocompatible coating, in which the biocompatible coating is capable of blocking diffusion of non-coating material through the coating material even while heated to a temperature greater than <NUM> degrees Celsius.

According to some embodiments of the invention, the biocompatible coating is thicker at a sharp end of the sharp tips than at a broader base of the sharp tips.

According to some embodiments of the invention, the biocompatible coating at the sharp end of the sharp tips is sufficient to block diffusion of non-coating material through the coating material to a level greater than <NUM>% concentration of the non-coating material in the coating material even following heating to a temperature between <NUM> and <NUM> degrees Celsius for a duration of at least <NUM> minutes.

According to some embodiments of the invention, the biocompatible coating material includes gold.

According to some embodiments of the invention, the non-coating material includes a material selected from a group consisting of copper, stainless steel, titanium and tungsten.

According to an aspect of some embodiments of the present invention there is provided an array of sharp tips for heating and treating tissue, the array including a plurality of sharp tips connected by a common base, and a biocompatible coating disposed on a distal tip of the sharp tips, wherein the biocompatible coating has a higher thickness on the distal tip of the sharp tips than at a broader section of the sharp tips.

According to some embodiments of the invention, the biocompatible coating is designed to remain biocompatible at temperatures between <NUM> and <NUM> degrees Celsius for a duration of at least <NUM> minutes.

According to some embodiments of the invention, the common base is not biocompatible at temperatures between <NUM> and <NUM> degrees Celsius.

According to some embodiments of the invention, the distal ends of the sharp tips have a width of <NUM> - <NUM> microns.

According to some embodiments of the invention, the biocompatible coating includes gold. According to some embodiments of the invention, the biocompatible coating is pure gold.

According to some embodiments of the invention, the biocompatible coating is designed to remain biocompatible during operation at <NUM> degrees Celsius. According to some embodiments of the invention, the biocompatible coating is designed to remain biocompatible following heating to a temperature of <NUM> degrees Celsius for a duration of <NUM> minutes.

According to some embodiments of the invention, the sharp tips and the base included a material selected from a group consisting of copper, stainless steel, titanium and tungsten.

According to an aspect not according to the invention there is provided a method of producing an array of sharp tips including a biocompatible coating, wherein the biocompatible coating is thicker at a sharp end of the sharp tips than at a broader section of the sharp tips, the method including providing an array of sharp tips, and coating the sharp end of the sharp tips differentially from coating the broader section of the sharp tips.

According to some embodiments the coating the sharp end of the sharp tips differentially from coating the broader section of the sharp tips includes electroplating the sharp tips, wherein the electric field at the sharp tips is larger than the electric field at the broader section.

According to some embodiments the coating the sharp end of the sharp tips differentially from coating the broader section of the sharp tips includes coating by plasma deposition of the coating, wherein the electric field at the sharp tips is larger than the electric field at the broader section.

According to some embodiments the coating the sharp end of the sharp tips differentially from coating the broader section of the sharp tips includes coating the sharp tips for a longer period of time than coating the broader section.

According to some embodiments the biocompatible coating is thicker at a sharp end of the sharp tips than at the broader section of the sharp tips by at least a factor of <NUM>.

According to an aspect not according to the present invention there is provided a method of producing an array of sharp metallic tips coated with a biocompatible coating, the method including providing an array of sharp tips, electroplating the array of tips with a first coating, providing a mask over the array of tips masking electroplating of the tip bases and exposing the tip distal ends, and electroplating the array of tips with a second biocompatible coating.

According to some embodiments the mask includes an insulating mask.

According to some embodiments the tips have a radius of curvature in a range from <NUM> to <NUM> microns.

According to some embodiments the array of tips is produced by sintering a powder including a material selected from a group consisting of copper, stainless steel and titanium.

According to an aspect not according to the present invention there is provided a method of producing an array of sharp metallic tips coated with a biocompatible coating including providing a first array of sharp metallic tips, providing a titanium sheet shaped as an array of hollow sharp tips of dimensions suitable for fitting onto the first array of sharp metallic tips, placing the titanium sheet onto the first array of sharp metallic tips such that the tips of the first array of sharp metallic tips insert into the hollow sharp tips of the titanium sheet, attaching the titanium sheet onto the first array of sharp metallic tips with a heat conducting layer.

According to some embodiments the attaching is by silver brazing.

According to some embodiments the titanium sheet is produced by sintering. According to some embodiments the titanium sheet is produced by coining. According to some embodiments the titanium sheet is produced by embossment. According to some embodiments the titanium sheet is produced by machining.

According to some embodiments , the sharp tips have an external distal tip width in a range from <NUM> to <NUM> microns.

According to an aspect not according to the present invention there is provided a method of treating skin including producing a hollow in the skin by heating and mechanically compressing epidermis while retaining a covering of stratum corneum.

According to some embodiments the epidermis is denaturated by the heating.

According to an aspect not according to the present invention there is provided a method of treating tissue including heating a tip to a temperature suitable for producing a crater in the tissue, advancing the tip toward the tissue, detecting when the tip comes into contact with the tissue by detecting a change in mechanical resistance to the advancing, and measuring the mechanical resistance to the advancing.

According to some embodiments the advancing the tip toward the tissue includes rapidly advancing the tip toward the tissue.

According to some embodiments further including when the tip comes into contact with the tissue, assessing mechanical compliance of the tissue based, at least in part, on the measuring the mechanical resistance to the advancing, and determining how to continuing to advance the tip based, at least in part, on one or more results of the assessing.

According to some embodiments the determining includes determining a preselected distance to advance beyond the detection of contact with the tissue.

According to some embodiments when the tip comes into contact with the tissue, starting to continuously assess mechanical compliance of the tissue.

According to some embodiments the determining includes advancing beyond the detection of contact with the tissue as long as the mechanical compliance remains lower than a threshold value.

According to some embodiments the determining includes advancing beyond the detection of contact with the tissue based, at least in part, on a result of calculating the following equation: <MAT> wherein F is a driving force advancing the tip, k is a constant, Y is a distance following contact with the tissue, D is an area of a cross section of the tip, µ is viscosity of the tissue, t is time measured following contact with the tissue, and Z is a distance from the tissue to a hard surface beneath the tissue.

According to some embodiments the tissue includes skin and the hard surface includes bone.

According to an aspect of some embodiments of the present invention there is provided a system for producing a crater in tissue by advancing a heated tip into the tissue, including a module for detection when the heated tip comes into contact with the tissue by detecting a change in mechanical resistance to the advancing.

According to an aspect not according to the present invention there is provided a method of producing a crater in tissue including assessing mechanical compliance of tissue, providing a controller with input corresponding to a result of the assessing, heating a tip to a temperature suitable for producing the crater in the tissue, advancing the tip toward and into the tissue, detecting when the tip comes into contact with the tissue by detecting a change in resistance to the advancing, and advancing the tip into the tissue a specific distance beyond the detecting, wherein the specific distance is determined by the controller based, at least in part, on a result of the assessing.

According to an aspect not according to the present invention there is provided a method of detecting when a tip of a tool being advanced toward tissue comes into contact with the tissue by detecting a change in resistance to the advancing.

According to an aspect not according to the present invention there is provided a method of cleaning a tip used for vaporizing tissue by heating the tip to a temperature above <NUM> degrees Celsius.

According to some embodiments of the invention, the tip includes a biocompatible coating material and a non-coating material, and the heating to a temperature above <NUM> degrees Celsius includes heating the biocompatible coating material to a temperature above <NUM> degrees Celsius.

According to some embodiments of the invention, a duration of the heating is long enough to burn off residue and short enough to prevent diffusion of the non-coating material through the biocompatible coating material.

According to some embodiments of the invention, the biocompatible coating material is sufficient to block diffusion of non-coating material through the coating material to a level greater than <NUM>% concentration of the non-coating material in the biocompatible coating material even following heating to a temperature between <NUM> and <NUM> degrees Celsius for a duration of at least <NUM> minutes.

Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings and images. With specific reference now to the drawings and images in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings and images makes apparent to those skilled in the art how embodiments of the invention may be practiced.

The present invention, in some embodiments thereof, relates to surgical devices, and, more particularly, but not exclusively, to devices for vaporization of tissue and even more particularly, but not exclusively, to devices for production of arrays of micro depressions in skin.

The term "skin" in all its grammatical forms is used throughout the present specification and claims interchangeably with the term "tissue" and its corresponding grammatical forms. Various implementations and embodiments of the invention which are described with reference to treating a skin are intended to apply also to treating other types of tissue.

The term "crater" in all its grammatical forms is used throughout the present specification and claims interchangeably with the term "depression" and its corresponding grammatical forms. Various implementation and embodiments of the invention which are described as producing craters in tissue are intended to apply also to producing depressions in tissue.

It is one purpose of embodiments of the current invention to overcome disadvantages of prior art while controlling a depth of vaporization of tissue with high temperature tips as well as improving post treatment conditions of patients.

An aspect of some embodiments of the invention involves using a tip of a heated rod or an array of tips of one or more heated rods, to produce a crater in skin. In some embodiments, the crater is produced in the epidermis while keeping at least some top layer of stratum corneum, which may cover the crater and potentially help prevent infection and assist healing.

An aspect of some embodiments of the invention involves a vaporizing element, such as a vaporizing rod, adapted to supply a large amount of heat in a short amount of time to produce the crater, while avoiding charring of the tissue. In some embodiments, holes, grooves, craters or indentations are produced in the tissue.

An aspect of some embodiments of the invention involves detecting when the tip(s) or array of tips comes in touch with skin, by detecting the mechanical resistance of the skin to the tips pushing against it. The mechanical resistance is detected, and optionally used for one or more uses. By way of one non-limiting example, detecting the mechanical resistance of the skin allows precise measurement of an advance from the point of touching the skin. By way of another non-limiting example, detecting the mechanical resistance of the skin enables determining a type of tissue being treated, and using the determination to calculate treatment parameters, such as depth of advancing the tip(s), speed of advancing the tip(s), and so on.

In some embodiments detecting when tip(s) come in touch with skin is meaningful when aiming for a specific depth and/or shape of the crater in the skin, since merely advancing tip(s) a specific distance beyond a plate placed upon the skin is likely to be inaccurate. It has been found that when placing a plate, which has openings for the tip(s) to go through, upon a skin, the skin may bulge into the openings, or otherwise not form a flat plane at the plate openings. A distance of advancement of a tip beyond the plate is not always equivalent to a depth of a crater formed in the skin. In order to control a depth of a crater formed in skin may be better done by detecting when the tip comes in touch with the skin and starts pushing against it.

An aspect of some embodiments of the invention includes measuring electric parameters such as current or voltage or pulse width (under Pulse Width Modulation) used in a motor for advancing the tip(s). When the tip(s) come into contact with skin the speed may change, or the electric parameters required to maintain the advance may change.

An aspect of some embodiments of the invention involves manufacturing an array of tips such as mentioned above, coated with a biocompatible coating, suitable for withstanding high temperatures used for treatment, optionally withstanding even higher temperature which in some cases may be used to clean a used tip array by combustion of carbon compounds and/or oxidizing residues and/or sterilizing.

In some embodiments the biocompatible coating material is selected to be capable of blocking diffusion of a non-coating material through the coating material even while heated to high temperatures over a period of time.

In some embodiments the biocompatible coating material is thicker at a sharp end of the tips than at a broader base of the tips. The different thickness may potentially be beneficial in blocking diffusion at a business end of the tips, which contacts tissue. Another potential benefit of the different thickness may be when using an expensive biocompatible coating material such as gold, by providing sufficient coating at the business end of the tips, which contacts tissue, and saving gold in a section of the tips which does not contact tissue.

Some embodiments of the invention are related to a thermal skin crushing element, such as a crushing rod, adapted to supply an amount of heat in a short amount of time to crush tissue or create a crater or depression while avoiding damage below the papillary dermis. The depression produced potentially remains depressed for a long time, for example for half a day, a day, or a few days.

An aspect of some embodiments of the invention relates to a generation of arrays of thermal micro-depressions in the skin, in some embodiments optionally without removing the stratum cornea. While vaporizing craters in tissue such as fractional vaporization of skin in aesthetic treatments, the stratum cornea is removed or partially removed as well. This happens with previous ablative technologies including CO<NUM> or Erbium lasers as well as in a system as described in above-mentioned <CIT>, which is limited only to stratum cornea ablation. The efficacy of aesthetic treatments for improvement of skin texture, including fine wrinkles, is based on thermally injuring the papillary dermis while trying to minimize collateral thermal damage.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings.

Reference is now made to <FIG>, which is a simplified block diagram illustration of a device <NUM> for vaporizing skin according to an embodiment of the invention.

<FIG> depicts an array of metallic tips <NUM> in contact with a heater <NUM>. The heater is held on a rod <NUM> which is driven back and forth toward and away from tissue surface <NUM> in a direction and speed U by a motor <NUM>. The array of (pyramidal or conical or flat) metallic tips <NUM> is optionally heated to a temperature between <NUM>-<NUM> deg C, typically <NUM> deg C, and gets in contact with the tissue surface <NUM> for a fraction of a second, typically between <NUM> milliseconds to <NUM> milliseconds, optionally dependent on desired skin treatment results. An array of craters is typically produced and skin remodeling is typically achieved. Tissue vaporization and collateral thermal damage depend on contact duration and/or tip protrusion from a distal plane <NUM> of the device <NUM>.

In some embodiments, not shown in <FIG>, the array of metallic tips <NUM> may optionally include one or more, or an array of blades, and/or arrow-like tips, with various diameters, optionally used for cutting soft tissue and/or for evaporating moles, lesions, tumors, etc..

Reference is now made to <FIG>, which is a simplified block diagram illustration of a focused beam CO2 laser <NUM> for vaporizing skin according to prior art.

<FIG> depicts a focused beam <NUM> of a prior art CO2 laser which is focused at point <NUM> on the tissue surface <NUM>. Infrared light absorption on the skin surface down to a depth of ~ <NUM> micron generates vaporization of a crater with collateral thermal damage.

Reference is now made to <FIG>, which is a simplified illustration of skin <NUM> showing three craters <NUM><NUM><NUM> in the skin <NUM> produced by three methods.

<FIG> depicts a first vaporized crater <NUM> in the skin <NUM> as typically obtained by a CO<NUM> laser, a second vaporized crater <NUM> as typically obtained by a high temperature pyramidal tip at <NUM> deg C such as described by above-mentioned patent application number <CIT> or obtainable by an embodiment of the invention, and a third thermally compressed crater <NUM> such as obtainable by an embodiment of the invention.

<FIG> depicts schematically three types of craters <NUM><NUM><NUM> produced during fractional skin resurfacing.

The first crater <NUM> is produced by action of a CO<NUM> laser according to state of the art laser treatments. In many cases of CO<NUM> treatments, arrays of the first type of crater <NUM> are produced. During the vaporization process, the ~ <NUM> micron thick stratum corneum <NUM> is vaporized as well as a result of an explosion of water vapors inside cells. In most such cases, vaporized crater depth is typically through epidermis <NUM> down to the papillary dermis <NUM> with thermal collateral damage <NUM> of ~ <NUM>-<NUM> micron. Each such first crater <NUM> of approximately <NUM> micron diameter and approximately <NUM>-<NUM> micron depth is an open wound which may be infected. In many typical cases there are ~ <NUM> craters per cm<NUM>, and a treatment area is typically <NUM>×<NUM><NUM>. Thus infection presents a risk.

The second crater <NUM> is produced by technology such as described in <CIT> and/or such as obtainable by an embodiment of the current invention. For example, the second crater <NUM> may be vaporized by a copper tip plated with gold or by a stainless steel tip plated with gold or covered with titanium. The tip temperature may be <NUM> deg C. Skin contact duration may be <NUM> - <NUM> milliseconds by a copper tip and/or two consequential pulses of <NUM> milliseconds each by a stainless steel tip and/or a titanium tip. Other thermal and treatment parameters are also described below. The second crater <NUM> is also typically an open wound, extending through epidermis <NUM>. However, there are a few advantages to the second crater <NUM> over the first crater <NUM> as will be explained below. However, the potential removal of the stratum corneum <NUM> has some disadvantages since care has to be taken to avoid infections.

The third crater <NUM> is typical of a new type of craters. The third crater <NUM> is optionally produced by a high temperature tip made from a low heat conductivity metal such as stainless steel, which may be gold plated for biocompatibility purposes. In comparison to the second crater <NUM>, the third crater <NUM> is produced with a skin contact time duration which is typically shorter, delivering less heat than required to vaporize a large volume of the skin <NUM>, optionally due to low thermal conductivity of the metal. Protrusion of a tip array from a distal end plate such as depicted by reference <NUM> in <FIG> is optionally controlled such that the high temperature tip pushes the skin <NUM> with some force F. As a result, the skin <NUM> is compressed without an explosive vaporizing effect which might destroy or ablate the stratum corneum <NUM>, and heat may optionally flow through epidermis <NUM>, to a selected, controlled, depth, such as down to the papillary dermis. The inventors believe that produced vapors may expand internally toward the dermis and may produce microchannels in the epidermis. The depth potentially depends on skin contact duration, advance velocity U, tip protrusion, and tip temperature as well as on a potential skin bulging into a distal opening of a treatment hand-piece. For example, a stainless steel tip at <NUM> deg C, contacting the skin <NUM> for <NUM> milliseconds in a single pulse, with a protrusion of <NUM> microns, will typically produce a conical crater of ~ <NUM> micron depth, potentially sized similarly to the second crater <NUM>. However, the stratum corneum <NUM> is not ablated, and will typically be compressed on the third crater <NUM> bottom, serving as a natural barrier to the wound and potentially assisting in avoiding infections.

In some embodiments conditions for non ablation of the stratum corneum during skin thermal compression include a utilization of a low-thermal-conduction pyramidal tip such as a gold coated stainless steel (thermal conductivity ~ <NUM> W/degrees C cm) and a short skin contact duration (less than or equal to approximately <NUM> milliseconds. ) and a tip temperature of approximately ~<NUM>- <NUM> deg C as well as a sharp (~ <NUM> microns in diameter) pyramidal or conical tip. It is noted that in some embodiments, in order to preserve the stratum cornea, the generation of vapors is optionally done so as to produce a low pressure, to overcome a potential crater sealing effect by the tips.

It is noted that a metallic tip or rod at room temperature (such as a distal end of a fork) may also generate a depression in skin if pushed against the skin. However, the depression will disappear within a short time, such as seconds, due to skin flexibility once the fork is removed. A high temperature tip such as in example embodiments, for example a temperature of above <NUM> degrees C, heats tissue down to a depth which depends on a heat diffusion constant of tissue and on skin contact duration. During the duration the skin is locally compressed. A denaturation of collagen due to heat potentially damages skin flexibility and enables a crater to remain compressed until healing, as in the case of the third crater <NUM>. An end result is a fractional skin resurfacing tool which is highly controlled and lets the stratum cornea be pushed against a crater bottom and serve as a natural bandage.

Reference is now made to <FIG>, which are images of three histology cross sections of three skin craters produced by three methods.

<FIG> depicts a histology cross section of a human skin crater produced by a CO<NUM> fractional skin resurfacing laser.

<FIG> depicts a histology cross section of a human skin crater produced by a vaporizing high temperature pyramidal tip at <NUM> deg C according to an example embodiment of the invention.

<FIG> depicts a histology cross section of a human skin crater produced by a non ablative thermal compression pyramidal tip at high temperature according to another example embodiment of the invention.

<FIG> depict crater histology cross sections produced by each of the above-mentioned methods.

<FIG> shows a histology cross section with a crater <NUM> in skin <NUM> obtained with a Quanta laser (Fractional CO<NUM> laser, "YouLaser", Quanta, 24W, 750µsec, <NUM> stacks, density <NUM>, 36mJ/point).

<FIG> shows a histology cross section with a crater <NUM> in the skin <NUM> obtained with a stainless steel pyramidal tip. The crater <NUM> is smaller in diameter than the laser crater <NUM> of <FIG>, and collateral thermal damage in a horizontal direction is smaller than in the laser crater <NUM>.

<FIG> shows a histology cross section of a thermally compressed crater <NUM> similar in size to the crater <NUM> of <FIG>. However, the crater <NUM> includes a stratum corneum cover to the crater <NUM> which is at least partly not vaporized and may potentially serve as a protective layer against infection. Treatment parameters used for producing the crater <NUM> include using a double heat pulse obtained by a gold coated stainless steel pyramidal tip in contact with the skin <NUM> for a duration of <NUM> milliseconds.

Reference is now made to <FIG>, which is a simplified line drawing illustration of a thermally compressed crater <NUM> in skin <NUM>, produced according to an example embodiment of the invention.

<FIG> depicts the crater <NUM> with a damaged layer <NUM> which potentially provides enhanced skin permeability to certain drugs (such as hydrophilic drugs) as compared to non treated skin. The type of damage may be necrosis, partial coagulation, or dystrophic vacuole alterations - a phenomenon of keratinocyte suffering which is smaller than necrosis.

In an embodiment of the invention, production of a crater by thermal compression of skin is utilized in order to enhance skin permeability to a variety of drugs or creams as compared to untreated skin. While utilizing example gold coated stainless steel sharp (~<NUM> micron distal width) pyramidal tips, with ~ <NUM>-<NUM> micron protrusion from a treatment hand-piece, and a pulse duration of <NUM>-<NUM> milliseconds, craters have been produced which are depicted in <FIG> ( in vivo human skin) and <FIG> (in vitro pig's ear skin), which are described below.

Reference is now made to <FIG>, which is a histology cross section of a thermally compressed crater <NUM> in skin <NUM>, produced according to an example embodiment of the invention.

<FIG> depicts pig ear skin <NUM> and a crater <NUM> which was produced by thermally crushing the skin <NUM>. The crushing was produced by a gold coated stainless steel tip (sharp ,<NUM> micron distal diameter) pressed into the skin <NUM> for a duration of <NUM> milliseconds. A stratum cornea layer <NUM> of the skin <NUM> is present, and is functionally damaged from a standpoint of skin permeability to some drugs. The depression of the crater <NUM> is a lasting depression, potentially lasting over hours and days, due to loss of elasticity of the upper skin which is believed to be caused by denaturation of proteins. It is noted that even a partial denaturation will induce a loss of elasticity - there is no need for necrosis. The loss of elasticity may also be caused by a production of microchannels following vapor explosion. It is believed by the inventors that the hot tip which is in contact with the skin serves at least partially as a seal for the crater, which potentially prevents at least some of the vapor from escaping out of the skin, potentially resulting in a creation of channels in the epidermis. This belief appears to be supported by the fact that vapors are not seen during application of the tip, as opposed to vapors and smoke which are seen during laser treatments. The above explanations of potential mechanisms for producing a lasting depression and an improvement in drug delivery are not meant to limit the scope of the invention.

Testing skin permeability through skin <NUM> treated to produce craters such as the crater <NUM>, over a period of <NUM> hours with a Franz diffusion cell, for the drug verapamil hydrochloride (<NUM>%), reveals that the skin permeability dramatically increases by approximately x10-x30 as compared to non treated skin.

Similar results were obtained in testing a sample of additional four in vitro skins.

Reference is now made to <FIG>, which is a graph <NUM> showing experimental results of measuring skin permeability for a drug according to an example embodiment of the invention.

The graph <NUM> has an X-axis <NUM> showing time in hours, and a Y-axis showing cumulative drug permeation on micrograms per square centimeter of tested skin.

<FIG> depicts a first line <NUM> showing average treated skin permeability as function of time, for a duration of up to <NUM> hours, and a second line <NUM> showing average treated skin permeability as function of time for untreated skin. It is apparent that the thermally depressed skin is transmitting drugs although epidermis has been altered.

Reference is now additionally made to <FIG>, which is a histology cross section of a thermally compressed crater <NUM> in skin <NUM>, produced according to an example embodiment of the invention.

The skin <NUM> in <FIG> is in vivo human skin.

<FIG> depicts a compressed crater <NUM>, a section of detached stratum cornea <NUM> which is damaged, and a zone <NUM> with dystrophic vacuole alterations which is about <NUM> microns deep. A trapezoid shaped zone between two lines <NUM> includes a zone with microchannels <NUM> which are not present in the surrounding skin <NUM>.

As can also be seen, cells along the microchannel direction are squeezed and not rounded. They have lost their shape, as a result of elasticity loss which may be associated with protein disruption.

For selection of operating parameters which potentially lead to production of thermally compressed craters such as the crater <NUM> depicted in <FIG>, a crater is described as having approximately a diameter 2R, a depth R <NUM>, and a collateral thermal dystrophic vacuole alteration zone <NUM> of depth R. For example, 2R is chosen to be <NUM> microns, crater depth is therefore R <NUM> is approximately <NUM> microns, and the dystrophic vacuole alteration zone depth <NUM> is <NUM> micron as well. During a process of thermal compression skin is believed to stretch as long as temperature does not attain a temperature which leads to at least partial denaturation of collagen, temperature is close to <NUM> degrees C, that is, collagen is still elastic.

An aspect of some embodiments of the invention relates to vaporization of tissue located on top of hard tissue. Some examples of such conditions include facial skin located below the eyes (such as lower eyelids), forehead skin, and palm skin. In the listed cases underlying bone is close to the skin layer, the distance between them being between approximately <NUM> and approximately <NUM>, depending on gender, age, and precise location on the body.

When advancing a vaporization tip toward a skin surface such that the tip is brought into contact with the skin, and further advancing beyond the skin surface, the skin mechanical impedance may potentially negatively affect the clinical result of such an advance, as explained below. This effect is particularly pronounced when bone structures are located close to the skin. The problem is now illustrated with the aid of <FIG>.

Reference is now made to <FIG>, which is a simplified line drawing illustration of a device <NUM> for skin treatment according to an example embodiment of the invention.

Reference is additionally made to <FIG>, which are simplified line drawing illustrations of the device of <FIG>, pressed against skin in an example embodiment of the invention where distance from skin surface to underlying bone is small.

<FIG> depicts a schematic presentation of a device <NUM>. The device <NUM> includes an array of tips <NUM>, which are heated to a temperature of approximately <NUM> -<NUM> deg C. A width of the tips array is depicted as D <NUM>. D <NUM> typically ranges between approximately <NUM> - <NUM>. D <NUM> may preferably be <NUM>. The device <NUM>, which may be a treatment hand-piece, is placed on a skin surface <NUM>. The array of tips <NUM> is advanced toward the skin surface <NUM>, and optionally set to protrude a distance Y <NUM> from a distal end <NUM> of the device <NUM>. The device <NUM> optionally vaporizes a crater array to a depth of X <NUM>. The protrusion Y <NUM> is sometimes useful even in case of a flat skin surface <NUM>, and is at least equal to X <NUM>. However, in many cases skin is slightly bulging <NUM> toward the device <NUM>. The bulging distance S <NUM> varies according to skin flexibility, according to pressure applied on the skin by operator. S <NUM> is proportional to R ^ (<NUM>~<NUM>), where R <NUM> is the opening diameter R of the distal end of the device <NUM>. The bulging distance S <NUM> may be typically <NUM> - <NUM> microns. For example, if S <NUM> is larger than the vaporization depth (such as in a case of the skin bulging <NUM> and the vaporization depth being <NUM> microns), the array of tips may optionally push the skin a distance larger than vaporization depth.

In some embodiments the advance of the array of tips <NUM> is optionally produced by an advancing mechanism such as, but not limited to, an electrical motor <NUM>, which may be a linear motor or a rotary motor. Advancing motion parameters such as, by way of some non-limiting examples, speed U <NUM>, acceleration, amplitude, and tip protrusion, are optionally controlled by parameters such as current i or voltage V supplied to the motor.

A value of crater depth X may be <NUM> microns to <NUM> microns, typically <NUM>-<NUM> microns. The protrusion Y <NUM> may be selected as approximately <NUM> - <NUM> microns, typically <NUM>-<NUM> microns, over a duration of <NUM> - <NUM> milliseconds, typically over a duration of <NUM> - <NUM> milliseconds.

While testing devices produced according to some embodiments of the invention, the inventors discovered that if the array of tips <NUM> is advanced too fast and/or too far within too short a duration on skin over a "bony zone", such as depicted by reference <NUM> in <FIG>, <FIG>, an impact was felt by a treated patient, pain was substantial, and treatment results were sometimes unsatisfactory. It is advantageous to control vaporization depth under these circumstances, without causing pain to the patient, by monitoring skin properties and rapidly modifying treatment parameters accordingly.

According to some embodiments, the treatment method and parameters are optionally modified to allow skin to be compressed during the advance of the tip array when in contact with tissue and not allowed to advance if skin becomes rigid due to its viscosity. This method is explained below.

A case is taken, for example, in which an advance velocity U <NUM> of the array of tips <NUM> is more rapid than a speed of a vaporization front along the crater axis for achieving a vaporization of a crater of depth X <NUM>. In such a case tissue is pushed forward during the tip advancement. Moreover, if a protrusion Y <NUM> is set to be greater than a desired crater depth X <NUM>, such as for example X=<NUM> microns, Y=<NUM> microns, the array of tips <NUM> may move a long distance without substantially increasing crater depth. In such a case, the array of tips <NUM>, which have an area of <NUM> × <NUM>, for example, compresses skin fluids away from a gap between the skin surface <NUM> and the bone surface to adjacent areas. However, the viscosity of the skin fluids may prevent this outward expulsion of fluids if distance Z <NUM> between bone and skin surface is small such as approximately <NUM>-<NUM>. As is explained below with reference to <FIG>, a computation of impedance caused by skin viscosity is optionally modeled using a theory of viscous lubrication of moving surfaces, such as described in above-mentioned text book chapter found on the World Wide Web at wwwf(dot)imperial(dot)ac(dot)uk/~ajm8/M3A10/lub(dot)pdf and the model may optionally be used in order to control and reduce negative effects on treatment. Such control is an aspect of some embodiments of the invention.

Referring now to <FIG>, since depth of vaporization is X <NUM> (<FIG>), since X < Y, and since skin will be pushed toward bone structure a distance of Y - X in order to advance a distance Y beyond the skin surface plane, a volume of tissue of approximately D x D x (Z-X) is displaced horizontally, as depicted in <FIG>. Since skin does not significantly bulge between the tips in a tip array if the distance between the tips is small, such as approximately <NUM>, the model of a lubricating viscous liquid (tissue) between two horizontal planes which are approaching each other at a relative velocity U <NUM> and squeezes the lubricating liquid out from the volume between the planes can be applied to the scenario of an advancing array of tips.

We now provide an equation which assists in estimating and quantitatively controlling the protrusion level Y desired in order to optionally avoid pain or other possible adverse effects, when the distance Z <NUM> of bone from skin surface is small.

While a plate <NUM> which represents the distal plane of the array of tips <NUM> in <FIG>, is moving at velocity U <NUM> and squeezing out viscous liquid <NUM> representing tissue, the squeezed volume is approximately Y* D<NUM>. The velocity U <NUM> is approximately Y/t, where t is a duration of the forward movement of the tips when beyond the plane of the skin surface <NUM>. The plate <NUM> is optionally pushed with a force F, generated by the motor <NUM>. A resulting pressure P <NUM> at a location of a middle point A <NUM> is approximately P = F/D<NUM>. The pressure at the edges of the plate <NUM> is approximately that of ambient liquid (body) pressure. The pressure differential causes the liquid to be squeezed out.

An approximate rate Q =Y * D<NUM> / t of material squeezing between two parallel plates is given by: <MAT> Where µ is a liquid (tissue) viscosity and c is a constant.

Equation <NUM> entails: <MAT> where k is a constant.

In some embodiments Equation <NUM> serves as at least a partial guide for setting control of a driving force by the motor <NUM>. It is noted that additional parameters may affect skin compliance as a function of tip velocity, such as, by way of a non-limiting example, skin surface elasticity. However, Equation <NUM> enables to quickly set a good order of magnitude for treatment parameters, for example as a function of a distance from bones, and further method steps potentially enable improved settings.

In controlling the driving force of the array of tips one or more of the following considerations are optionally used:.

In addition, in order to further refine the control parameters, the distance Z of bone from skin surface may be measured, for example by pressing the skin with a micrometer, or with use of an ultrasound unit, and the results may be input to a data table.

In some embodiments the control of F or of the protrusion level Y or of other treatments parameters as described above may be based on open loop control methods and/or on closed loop control methods. Descriptions of embodiments of both types of control methods are described below.

Reference is now made to <FIG>, which is a simplified flow chart illustration of an open loop control method of selecting treatment parameters according to an example embodiment of the invention.

In some embodiments an operator evaluates a distance which the operator's finger advances before encountering rigid tissue. By way of a non-limiting example, a distance of ~ <NUM> may optionally correspond to compliance of level <NUM>, while a distance of <NUM> corresponds to compliance of level <NUM>. In some embodiments the classifying includes using ultrasound to assess the mechanical compliance of the tissue, for example by measuring the depth from tissue surface to bone.

It is noted that clinical tests performed by the inventors on patients have revealed that an open loop setting method of setting treatment parameters according to mechanical skin classification by tactile feedback considerably improves results and eliminated pain.

Reference is now made to <FIG>, which is a simplified line drawing illustration of an example embodiment of a tissue treatment hand-piece <NUM> according to an example embodiment of the invention.

<FIG> depicts the treatment hand-piece <NUM>, designed to vaporize craters in tissue using a linear motor <NUM>, such as produced by Faulhaber Minimotor SA, Switzerland. The linear motor <NUM> is located in the treatment hand-piece <NUM>, which also includes a position encoder <NUM>. The position encoder <NUM> optionally provides information enabling a calculation of a position of a rod <NUM>, which is driven by the linear motor <NUM>, relative to a reference plane. Extending the rod <NUM> pushes a heater and treatment pins (not shown in <FIG>) toward skin and back from the skin. A distal cover <NUM> is optionally placed on skin. The distal cover <NUM> may optionally be transparent, optionally providing a good view of a treatment site, and may optionally incorporate holes in order to enable suction of air from a treatment site into the hand-piece <NUM>. The position encoder <NUM> optionally provides a position accuracy on the order of <NUM> micron, and may be a magnetic array type encoder (such as a magnetic type encoder produced by Texas Instruments, USA), or an optical encoder or a Hall effect detector.

In some embodiments the linear motor <NUM> is optionally operated at a constant voltage and the force applied by the linear motor <NUM> on the tip array is optionally controlled by a controller <NUM> by modulating width of pulses applied to the linear motor <NUM> (Pulse Width Modulation = PWM). A velocity of the rod <NUM>, which is equal to the tip velocity, is optionally monitored by monitoring a time derivative of the rod <NUM> position. Following advance toward tissue and upon contact with treated tissue, the velocity of the rod <NUM> may be reduced, optionally in cases where it is know that skin mechanical compliance is low. As described above, skin mechanical compliance depends on tip array protrusion and/or distance of bone under the skin, among other considerations. Once velocity reduction, caused by the array of tip pressing against skin, is detected, the controller <NUM> optionally modifies the width of pulses applied to the linear motor <NUM>, optionally so that original velocity is restored.

In some embodiments, the protrusion of the tip array may also be modified according to the skin mechanical compliance. Modifying the position is possible since the position of the rod <NUM> is known, optionally even with <NUM> micron accuracy. As a result, a closed loop method enables a vaporization of craters with high depth accuracy on the order of a few microns regardless of tissue type, by measuring protrusion.

In some embodiments an automatic control of side effects such as pain due to mechanical impact and/or injury is potentially obtained based on controlling depth. Since it is believed that there is a relation between mechanical skin compliance and clinical side effects, controlling depth instead of trying to achieve a desired depth using open loop control may potentially reduce pain.

Reference is now made to <FIG>, which is a simplified flow chart illustration of a method of producing craters in tissue according to an example embodiment of the invention.

The example method of <FIG> includes:
Optionally entering one or more initial treatment parameters (<NUM>) such as, by way of a non-limiting example, type of tip array, area of tip array, duration for tips to press against tissue, depth to which tips should press into tissue, protrusion of tips from end plate, and so on, as input into a treatment device.

Optionally placing the treatment device on a treatment site (<NUM>). Optionally, the placing includes placing an end plate of the treatment device directly against skin.

Advancing treatment tip(s) or array of tips toward tissue (<NUM>).

Detecting contact of tips with tissue (<NUM>). It is noted that skin may bulge through an opening in the end plate, or that skin may not lie flat against the end plate, so that contacts of the tips with tissue does not necessarily happen immediately when the tips protrude from the end plate.

Advancing tips into tissue (<NUM>). In some embodiments the distance advanced into tissue is measured by an encoder measuring a distance advanced following detection of contact with tissue. In some embodiment, a motor driving the tip advancement optionally acts to maintain a constant advancement speed, optionally using a closed-loop method of control over the speed. In some embodiments the motor driving the tip advancement optionally acts to maintain a constant force against the tissue. In some embodiments, the motor driving the tip advancement optionally acts to maintain a force no greater than a specific threshold force against the tissue.

Detecting reaching a target depth into the tissue (<NUM>).

Retracting the treatment tip(s) from the tissue (<NUM>).

In some embodiments the treatment tip is optionally left at the target depth into the tissue for a specific period of time (not shown in <FIG>).

In some embodiments, the tissue or skin may be a thin layer over bone, in which case producing a crater in the skin to a target depth has a potential to cause pain.

In some embodiments, the above-described method is used to advance tips into tissue. When the tips advance into the tissue, the tissue impedance is measured, and provided as data upon a control and/or input display of the treatment device. The measured tissue impedance device may then optionally be fed, manually or automatically, into the treatment device.

In some embodiment a new treatment may be carried out at the same treatment site or at a nearby treatment site, using the measured tissue impedance.

In some embodiments the measured tissue impedance is optionally used as feedback to determine treatment parameters during a single treatment.

Reference is now made to <FIG>, which is a simplified flow chart illustration of a method of producing craters in tissue according to another example embodiment of the invention.

Measuring impedance to the advancing of the tips (<NUM>).

Optionally amending treatment parameters (<NUM>) based on the measured impedance.

Detecting end of advancement into tissue (<NUM>).

In some embodiments the measuring impedance to the advancing of the tips (<NUM>) is performed continually, both while the tips are not yet touching the tissue, and when the tips are moving into the tissue.

In some embodiments the amending treatment parameters (<NUM>) is optionally based on the measured impedance, and may optionally include several options:.

In some embodiments of the invention, closed loop control of vaporizing depth and selection of tip protrusion relative to the distal gage <NUM> of <FIG> is optionally performed by controlling a single treatment pulse (pulse width modulation) on a selected area.

In some embodiments the method of <FIG> is used to measure mechanical compliance or resistance of the skin in a treatment site. This is optionally done by treating a small, for example <NUM><NUM>, area with a single advancement pulse of the treatment tips, and selecting a very shallow crater depth target. This pulse negligibly affects tissue. Once shallow target depth has been attained, skin compliance is measured by slowing the tip and measuring the current reduction necessary to reduce the speed as compared to a speed reduction for movement of the tips in air. Based on the measured skin compliance, automatic parameter correction is optionally performed. In some embodiments, there is no further need to continue activation of closed loop control. A corrected parameter may be for example a protrusion distance, which may be reduced if skin compliance is too low (a sign of skin being close to a bone). Another parameter which is optionally changed is skin contact duration, which may be reduced if compliance is low.

In some embodiments, closed loop monitoring of parameters according to skin mechanical compliance may lead to control of selection of size of tips array, optionally in accordance with Equation <NUM>.

In some embodiments, the tip array is optionally located approximately <NUM> from tissue while in idle condition prior to triggering a treatment pulse. The offset distance from the skin is intended in order to potentially lower infrared radiation emitted from the high temperature array of tips (~<NUM> deg C) which may generate discomfort to a patient.

In some embodiments, the hand-piece <NUM> body of <FIG> is optionally chilled by air flow, which optionally flows in a direction away from the patient. Airflow is optionally controlled by a fan <NUM> (<FIG>) and/or by an air pump <NUM> (not in <FIG>) which may be located at an end of a hose. Holes <NUM> in the distal gage <NUM> optionally enable the air flow. An optional temperature sensor (not shown) optionally controls air flow and keeps the hand-piece <NUM> temperature at a reasonable level such as <NUM> deg C. The chilling flowing air optionally flows over an outside of a heat radiator <NUM>, the radiator <NUM> surrounds a heater (not shown in <FIG>), and conveys heat generated in the hand-piece <NUM> by the tip array heater and by an array of tips (not shown in <FIG>) by radiation and/or conduction.

In some embodiments, electrical wires (not shown) connected to the heater and optionally moving with the heater are rigid. Flexible extension wires are optionally connected to the rigid wires and to the electrical supply of the heater.

In some embodiments, a safety spring <NUM> is located on the rod <NUM> and attached to the hand-piece <NUM>, and optionally applies a restoring force F to the advancing tips when advancing toward tissue. The role of the spring <NUM> is to ensure lack of contact between the hot tip array and the skin in case of a failure of the electrical or control system. Upon any failure, electrical supply is optionally shut down and the spring <NUM> automatically retracts the high temperature array of tips away from tissue. In some embodiments the restoring force of the spring <NUM> is larger than required to lift a weight of the advancing parts in order to overcome even gravitation.

In some embodiments of the invention there is a warning element which indicates a type of skin which is highly compliant, or highly resistant such may occur over bones. The warning element may be, by way of some non-limiting examples, alight or an acoustic signal.

As explained above, in some cases of treatment skin may bulge into a treatment hand-piece. This is particularly true when skin is highly compliant, for example on cheeks. In such cases it is sometimes desirable to vaporize a crater to a controlled pre-specified depth and immediately retract the vaporizing tip array, avoiding additional forward movement intended to compress the skin.

In some embodiments, a closed loop control available while driving the motor <NUM> of <FIG> or the linear motor <NUM> of <FIG> enables achievement of the above objective. The rod <NUM> is initially advanced by the motor while the array of vaporizing tips is moving in air. This requires a force F which may vary over time, and may be optionally programmed into a controller.

Upon reaching contact with skin, mechanical resistance (or impedance) felt by the motor increases. The mechanical impedance produced by pushing against skin acts to reduce the velocity of the rod <NUM>. Since the position encoder <NUM> is constantly measuring a position of the tips array, and monitoring velocity, the position encoder <NUM> detects the velocity slowdown. The controller <NUM> is optionally programmed such that upon detection of a velocity slowdown a command is provided to the motor to reverse motion direction.

Reference is now made to <FIG>, which is an oscilloscope trace <NUM> of a position of an array of tips and of a driving current of a linear motor driving the array of tips in air according to an example embodiment of the invention.

Reference is additionally made to <FIG>, which is an oscilloscope trace <NUM> of a position of an array of tips and of a driving current of a linear motor driving the array of tips including a period of time touching impeding skin according to an example embodiment of the invention.

<FIG> and <FIG> have X-axes <NUM><NUM> of time, <NUM> milliseconds per division and Y-axes of tip position <NUM><NUM>, <NUM> per division, and driving current <NUM><NUM>, <NUM> A per division, of a linear motor controlled using a closed loop control method of Pulse width Modulation (PWM).

<FIG> depicts an upper trace1610 showing tip position as a function of time, with the tips moving in air. Section AB of the upper trace <NUM> corresponds to the tips advancing, section BC of the upper trace <NUM> corresponds to the tip at maximal advance, and section CD of the upper trace <NUM> corresponds to a retraction phase of the tips.

<FIG> depicts a lower trace <NUM> showing a driving current used to advance the tips. The driving current depicted by the lower trace <NUM> appears substantially constant, barring noise artifacts. The driving current depicted by the lower trace <NUM> corresponds to mechanical impedance to the tip movement by tissue - no skin contact.

<FIG> depicts an upper trace1640 showing tip position as a function of time, with the tips moving into contact with tissue, in the example of <FIG> the tissue is the skin of a finger placed in the path of the tips. Section EF of the upper trace <NUM> corresponds to the tips advancing into the tissue, and section GH corresponds to tip retraction.

<FIG> depicts a lower trace <NUM> showing a driving current used to advance the tips. The driving current depicted by the lower trace <NUM> appears shows a current increase in the section EF. The advancing tip came into contact with the skin at point E and gradually pushed the skin while compressing it. In the example embodiment depicted by <FIG> the tip speed is controlled to be constant, as mat be seen by the constant slope of the upper trace <NUM> over the section EF. The driving current is proportional to the driving force, which is proportional to a resisting force in order to maintain the speed, and the resisting force is believed to be proportional to depth. The driving force and current reach a maximum at point F, which corresponds to the deepest depression. <FIG> shows a capability of detecting contact with skin as well as optionally determining a depth of depression based on force feedback which in some embodiments relates to the driving current.

Reference is now made to <FIG> which is a simplified line drawing illustration of an array of vaporizing tips according to an example embodiment of the invention.

Reference is also made to <FIG> which are images of the example embodiment of <FIG>.

<FIG> depict an array of treatment tips which is coated or plated with a biocompatible material which is biocompatible when operating at high temperatures.

<FIG> depicts an array of vaporizing tips <NUM>. The array of vaporizing tips <NUM> includes metallic pyramidal tips which may be produced by mechanical machining and/or by sintering. In some embodiments each pyramid base width is approximately half its height. A typical width may be <NUM> micron while its height may be <NUM> micron.

In some embodiments the pyramids are optionally truncated at their tips <NUM>.

In some embodiments the pyramids are optionally rounded at their tips <NUM>. In some embodiments the tips remain relatively sharp: in some embodiments the distal width of the pyramid tips is smaller than <NUM> microns. In some embodiments the tips of the pyramids have a distal radius smaller than <NUM> micron. It is noted that small tips distal width enable a vaporization of craters in the skin with minimal thermal damage between craters and less thermal damage than typically achieved with CO<NUM> lasers, resulting in improved treatment results relative to lasers.

<FIG> depicts an example embodiment array of vaporizing tips <NUM> which have a core <NUM> and are plated or coated with a biocompatible metallic envelope <NUM>. The core <NUM> may be made from, by way of some non-limiting examples, copper and/or stainless steel and/or titanium and/or tungsten. The coating or plating may be made from, by way of some non-limiting example, gold and/or titanium. In some embodiments the tips are anodized.

In some embodiments, an adhesion between a biocompatible external surface, or envelope <NUM>, and the core <NUM> may be achieved, by way of some non-limiting example, by silver brazing and/or by electroplating. By way of a non-limiting example, a layer of silver brazing <NUM> is depicted on the left side of <FIG>. The right side of <FIG> is depicted without the layer of silver brazing <NUM>, not necessarily as an embodiment including both brazed and non-brazed areas, but as a way to show two possible methods of fastening the envelope <NUM> to the metallic core <NUM> in the one <FIG> In some examples the envelope <NUM>, such as a titanium envelope, is optionally produced by sintering or by embossing or by coining.

In the case of copper tips, biocompatible gold plating is formed over a layer of nickel which is coated over the copper. Copper is a soft metal which becomes less stable at temperatures above <NUM> degrees C. At such temperatures, the tip array is sometimes crushed or distorted upon touching hard materials, potentially even upon pressing against non compliant tissue such as thin tissue over a bone. At higher temperatures, such as above <NUM> degrees C and above <NUM> degrees C, which are used in some embodiments to clean the tips, coating a thin layer of gold (<NUM>-<NUM> micron) on a nickel layer which is coated on top of sharp pyramidal tips of copper may be problematic - copper and nickel may diffuse into the gold layer and the gold coating with other metallic impurities becomes unsuitable as a biocompatible coating. This is particularly true when an array of pyramidal tips is produced by sintering. Sintering typically causes copper density reduction and produces micropores which limit dimensional accuracy of features below <NUM> microns, or <NUM> microns, or even <NUM> microns in size.

A common solution for the problem of potential deterioration of a gold coating of a sintered object is to use hard gold - gold with ~ <NUM>% impurity of cobalt. However, cobalt is not a biocompatible material and also oxidizes at high temperatures, which may cause cobalt to be incompatible with clinical use. As a result, in some embodiments, hard gold may not suit to serve as a plating material for high temperature tips for treating tissue.

Other production methods for an array of tips, such as machining or electro-abrasion may be expensive in mass production due to the softness of copper, and are typically considered more stable against potential deterioration. The inventors have found that machined copper tips, as well tip arrays produced by electro-erosion are sometimes not tough enough for regular gold plating when intended to reaching high temperatures such as ~ <NUM>-<NUM> degrees C. The inventors electroplated the tips with a nickel sub-layer and with a relatively thick <NUM> microns pure gold layer. The gold layer was found to be not biocompatible after less than half an hour of utilization at <NUM> degrees C.

In some embodiments, an array of tips with metallic pyramidal or conical tips which are biocompatible and can withstand prolonged heating over <NUM>-<NUM> degrees C is produced as follows:
In some embodiments sharp sintered copper tips with a distal width of <NUM>-<NUM> microns and a slope of <NUM>-<NUM> deg are used. For some embodiments a specific sintering mold has been developed with 9X9 pyramidal with sharp craters having a <NUM> micron distal diameter. The distance between crater centers is <NUM> and the depth is <NUM>.

Once produced, the tip array unit, including tip bottom supports, are plated with a layer of <NUM>-<NUM> microns of gold, optionally on top of a nickel sub-layer. Such a gold layer would typically oxidize upon attaining a temperature of <NUM> degrees C, and would not be biocompatible. However this gold layer will not come in contact with tissue.

In some embodiments, following a first gold layer deposited as described above, the distal tip sections which will come in contact with the tissue is them further electroplated. The further electroplating includes placing a mask over the tip array, preventing gold electroplating of the tip bases, and exposing the tip distal ends. A synergistic benefit of the mask is saving gold, since the surface is large and gold is expensive. The pyramidal tips are exposed to the plating solution. Plating voltage is applied through the mask to the metallic tip. The mask is optionally painted with an insulating paint which shapes the electrical field, producing a thickness gradient between the sharp distal end, which receives a thicker coating, and the base of the tips, which receives a thinner coating. The difference in coating thickness is due to a combination of the non conductive mask and to a stronger electric field close to the sharp tip end.

In some embodiments parameters of the electroplating process such as duration, dissolved metal solution concentration, voltage and so on, are not as would be typically used for plating a specific thickness over an entire surface of the array of tips, but according to the plating thickness of the sharp end of the tips, which is the part planned to contact tissue. For example, a gold plating thickness of ~ <NUM> - <NUM> microns on the sharp distal end of the tip is used, a thickness gradient is produced along the surface of the tips, and the bottom of the tips is plated with only a <NUM> micron gold layer. It may be too expensive to plate an entire surface of a tip array with an <NUM> micron pure gold layer, requiring tens of hours of electroplating and costing orders of magnitude more than coating just the ends of the tips.

Properties of the gold coating on a distal end of a tip after heating the tip to <NUM> degrees C for a duration of <NUM> minutes and also an equivalent of <NUM>,<NUM> treatment pulses at <NUM> degrees Celsius were measured. The measurements were done with an electron surface scanning microscope and with EDM (Electric Dipole Moment) spectroscopy. The results showed very high stability of the coating. The results show that an <NUM> micron gold layer was intact after the above-described heating, and copper as well as nickel have diffused only a distance of up to <NUM>-<NUM> microns. A pure gold layer of over <NUM> microns is present, rendering the tip biocompatible and even reusable. Tips can potentially be cleaned and sterilized for at least <NUM> cycles at a temperature of <NUM> degrees C. A similar test was performed with a sintered array of gold plated stainless tips with similar good results.

It is noted that the same electroplating process without the mask produced a gold layer only <NUM> microns thick on the sharp distal end and a negligible gradient between the distal end of the tip and the rest of the tip array surface. The gold layer became not biocompatible after heating the tip to <NUM>-<NUM> degrees C for the above-mentioned duration.

Reference is now made to <FIG>, which are cross section images <NUM><NUM><NUM> depicting stainless steel tips <NUM> coated with a gold coating <NUM> according to an example embodiment of the invention.

<FIG> depicts a stainless steel base <NUM> and stainless steel tips <NUM> coated with gold coating <NUM>.

<FIG> depicts an enlarged section of <FIG>, showing one tip <NUM>, and gold coating on the tip <NUM>. <FIG> shows approximately <NUM> micron thick gold coating at the tip and approximately <NUM> micron thick gold coating on the sides of the tip.

<FIG> depicts an enlarged section of <FIG>, showing a bottom section of the stainless steel base <NUM>, and gold coating on the base <NUM>. <FIG> shows approximately <NUM>-<NUM> micron thick gold coating at the least thick section of the base <NUM>.

The thickness gradient of the gold coating is evident - <NUM> microns on the distal tip which is expected to contact the skin, and only <NUM> microns on the bottom. Most of the coated area has shallow coating, and the tips have much thicker coating.

Reference is now made to <FIG>, which is a graph <NUM> depicting concentration of elements as a function of distance along the stainless steel tips and the gold coating of the example embodiment of <FIG>.

The graph <NUM> has an X-axis <NUM> of distance in microns, and a Y-axis <NUM> showing percentage of the elements in the material at the distance measured.

A first line <NUM> in the graph <NUM> shows concentration of Chrome (Cr).

A second line <NUM> in the graph <NUM> shows concentration of Iron (Fe).

A third line <NUM> in the graph <NUM> shows concentration of Nickel (Ni).

A fourth line <NUM> in the graph <NUM> shows concentration of Copper (Cu).

A fifth line <NUM> in the graph <NUM> shows concentration of Gold (Au).

The stainless steel tips and the gold coating of the example embodiment of <FIG> were heated at <NUM> degrees C for a duration of <NUM> minutes.

<FIG> depicts a distribution of elements up to a depth of approximately <NUM> microns from a surface of the coating. A layer of close to <NUM> microns of pure gold is present. Iron and Nickel have not diffused beyond approximately <NUM> microns.

Reference is now made to <FIG>, which are cross section images <NUM><NUM> depicting copper tips <NUM> coated with a coating <NUM> of nickel followed by gold according to another example embodiment of the invention.

<FIG> depicts a copper base <NUM> and copper tips <NUM> coated with the nickel followed by gold coating <NUM>.

<FIG> depicts an enlarged section of <FIG>, showing one tip <NUM>, and the nickel followed by gold coating on the tip <NUM>. <FIG> shows an approximately <NUM> micron thick coating at the tip and an approximately <NUM> micron thick coating on the sides of the tip.

Reference is now made to <FIG>, which is a graph <NUM> depicting concentration of elements as a function of distance along the copper tips and the nickel followed by gold coating of the example embodiment of <FIG>.

A first line <NUM> in the graph <NUM> shows concentration of Gold (Au).

A second line <NUM> in the graph <NUM> shows concentration of Copper (Cu).

In the sample of the example embodiment of <FIG> the gold layer is <NUM> micron thick at the tip, and a layer of over <NUM> micron of pure gold is present although the tips were heated to a temperature of <NUM> degrees C for <NUM> minutes. Since in some cases a duration of a skin rejuvenation treatment may last close to <NUM> minutes, the inventors heated the tips for a duration longer than <NUM> minutes.

In some embodiments, the array of tips is produced by using sintered copper tips which are electro-coated coated with a <NUM>-<NUM> micron nickel layer and further electro-coated by a <NUM>-<NUM> micron gold layer. It is noted that electroplating may produce a thicker coating at the tips, which are sharp and concentrate electric field. It is believed that electroplating the tips produces a synergy whereby the thicker plating is located where the array meets the tissue, and that the bio-compatible plating over a sintered array of tips is preferably formed by electroplating.

In order to test that the copper and nickel do not diffuse into the gold layer the array of tips was heated to a temperature of <NUM> degrees C for a duration of <NUM> minutes and tested with an electron microscope for gold layer stability and with X-ray spectroscopy for Cu, Ni and Au concentrations as function of depth. The result showed high gold stability even at the sharp distal end of the tips as well as no diffusion of Cu or Ni to the surface.

A similar test was performed with a sintered array of stainless steel tips with good results.

The tests and results are described in more detail below with reference to <FIG>.

In some embodiments the tips may also be made from glass or ceramic.

<FIG> is an image of an array of tips made of stainless steel and coated with a <NUM> micron layer of gold. The coating layer of the distal tips is approximately <NUM> microns thick. The tip distal width is <NUM> microns.

In some embodiments the shape of the array of tips may be square, such as <NUM>×<NUM> tips, for example on a <NUM><NUM> area, or elongated such as a 3x10 tip rectangle, for example of <NUM> length and <NUM> width. An elongated array of tips may be useful while treating eyelids or upper lips, for example. The narrow elongated tip array near the eyes and lips or on the nose enables to avoid touching the eyes and/or the lips during treatment. The elongated array of tips may also be useful when treating very thin skin on bones as explained above, due to the dependency of Equation <NUM> on area D.

Reference is now made to <FIG>, which is a microscope photograph of an array of pyramidal craters <NUM> produced by an array of pyramidal tips according to an example embodiment of the invention.

The pyramidal craters <NUM> were produced by an array of gold coated stainless steel pyramidal tips having a distal width of <NUM> micron. The distance between crater centers is <NUM> microns. The clean pyramidal shape of the crater is shown as well as thin collateral thermal damage having a width of only <NUM> microns.

In some embodiments the inventors have discovered, after a series of histologies as well as clinical tests, that the size of the distal end of the tips is preferably smaller than <NUM> - <NUM> microns.

Reference is now made to <FIG>, which is a simplified flow chart illustration of a method of producing an array of sharp metallic tips coated with a biocompatible coating according to an example embodiment of the invention.

In some embodiments, the mask is an insulating mask.

In some embodiments, the array of tips is produced by sintering a powder.

In some embodiments, the powder is a material such as, by way of some non-limiting examples, copper, stainless steel and titanium.

Reference is now made to <FIG>, which is a simplified flow chart illustration of a method of producing an array of sharp metallic tips coated with a biocompatible coating according to another example embodiment of the invention.

In some embodiments, the attaching is by silver brazing.

In some embodiments, the titanium sheet is produced by sintering. In some embodiments, the titanium sheet is produced by coining. In some embodiments, the titanium sheet is produced by embossment. In some embodiments, the titanium sheet is produced by machining.

In some embodiments, array of tips are reusable and may be cleaned between treatments.

In some embodiments, tip cleaning is performed by heating the surface of the tips to a high temperature, high enough to oxidize organic material, so that carbon is oxidized into CO<NUM>. Experiments performed by the inventors have shown that heating the tips above <NUM> - <NUM> deg C eliminates any traces of carbon on the tip. The heating duration may be of only few minutes, for example approximately <NUM> minutes.

In some embodiment of the invention the heating is performed by increasing a current through a heater which heats the array of tips.

However, some heaters are not designed to withstand temperatures as high as <NUM> deg C.

Furthermore, when a gold coated copper tip is utilized, it may be preferable if only the gold surface is heated to a cleaning temperature, and the core material is less heated.

Reference is now made to <FIG>, which is a simplified line drawing illustration of
a heating lamp which heats a distal surface of an array of tips according to an example embodiment of the invention.

<FIG> depicts an array of tips <NUM>, optionally coated by a biocompatible coating <NUM> such as gold. A lamp <NUM> such as a halogen lamp produced by Herreaus, Germany, and a reflector <NUM> are optionally positioned close to an array of tips which is to be cleaned and/or sterilized. In some embodiments two or more lamps are used in parallel.

Using, by way of a non-limiting example, a lamp of <NUM> watts over a duration of <NUM> minutes, the surface of the array of tips is heated to a temperature of <NUM>-<NUM> deg C , while not overheating the core material of the pyramids, for example not above <NUM> deg C.

In some embodiments the core material is kept from overheating by placing the tip array on a cooling, heat-conducting surface. In some embodiments the back side of the array of tips, which is optionally placed against a heater when in treatment mode, is placed against the cooling surface.

As a result of not overheating, thermal and mechanical properties of the pyramidal tips are preserved. The lamp cleaning assembly may be located in a console of a fractional skin resurfacing unit, or separately.

Reference is now made to <FIG>, which are simplified line drawing illustrations of end plates of a treatment device according to an example embodiment of the invention.

<FIG> provide a bottom view of a distal, toward-skin-side, end plates <NUM><NUM> or distal gages of a skin treatment device and/or hand-piece. The endplates <NUM><NUM> include optional transparent envelopes <NUM> and/or a transparent distal surface <NUM> which may be placed on the skin. Transparency is potentially beneficial for a better view of a treatment site, including enabling to locate treatments sites well aligned next to each other. Openings <NUM><NUM> enable arrays of tips <NUM><NUM> to treat tissue.

In some embodiments, the end plates <NUM><NUM> have different sizes of openings <NUM><NUM>.

In some embodiments a size of an opening is not simply chosen to fit a largest array of tips <NUM><NUM>, based on safety considerations. When an array of tips <NUM><NUM> contacts skin, thermal contact generates micro craters in the skin. In some cases the skin does not touch hot metal between the tips since the skin is not flexible enough.

In some embodiments, a tip array <NUM> may be produced by removing some tips from an array of tips <NUM> originally having more tips. In such cases skin may contact with hot metal in the region <NUM> where tips have been removed. By protecting the array of tips <NUM><NUM> with distal plates <NUM><NUM> as in <FIG>, such a condition may potentially be avoided.

In some embodiments a distal endplate includes two slits which enable changing a used array of tips with a new array of tips without removing the distal endplate , as described below with reference to <FIG>.

In some embodiments a treatment device for thermal tissue vaporization and compression is designed so there is no possibility to unintentionally touch a high temperature tip array, for example with a finger or hand. Openings in the distal gage mentioned above are small - smaller than the dimensions of the tip array unit which includes an array support, while still large enough to enable skin treatment to be performed (for example larger than <NUM> millimeters per side).

In some embodiments, it is desirable to discard a used tip array after a treatment session, so that a clean and/or disinfected tip may be used in the next treatment. Changing tips should preferably be rapid, for example taking no more than <NUM>-<NUM> minutes, and should be possible to perform at high temperature such as <NUM> degrees C, since the cooling off period for a tip array may be longer than the changing time.

In some embodiments, changing tips is optionally done by sliding the tip array unit sideways relative to the distal gage, through a slit and out of the treatment device, without overheating the distal gage and/or risking operator safety, even while at high temperature. The tip array which is hot is dropped into a box for safe keeping and cooling off. Charging a new tip into the treatment hand-piece is also preferably rapid, and optionally performed as part of a same tip array changing procedure. In some embodiments, it is advantageous to change the tip array using a small unit such as a console with a single motor. Furthermore, a hot (temperature above approximately <NUM> degrees C) array of copper tips may be soft and distort if exchanged incorrectly or by using excessive force.

In some embodiments it is advantageous to change tips in a small closed console.

In some embodiments the tips are changes by pushing a sliding mechanism by hand and/or better by a motor.

Reference is now made to <FIG>, which are simplified line drawing illustrations of a mechanism for quick change of an array of tips according to an example embodiment of the invention.

The example mechanism depicted in <FIG>potentially enables exchanging a used array of tips with a new array of tips while the used array of tips is still hot.

In some embodiments of the invention an array of tips may be removed from a treatment hand-piece after one or more treatments, to be replaced by a new array of tips. Moreover, arrays of tips may be removed while still hot, for example even <NUM> deg C. In addition, the arrays of tips may be removed safely while still hot without endangering hands or fingers which are holding the hand-piece.

<FIG> depict a compartment or console <NUM> which includes an opening <NUM> through which a treatment hand-piece <NUM> or part of the treatment hand-piece <NUM> may be introduced.

<FIG> depicts a mechanism <NUM> which may be operated manually, or operated by a motor, whereby an extension rod <NUM> or plate optionally pushes a first array of tips <NUM> away from the hand-piece <NUM>. The first array of tips <NUM> may be at any temperature. Once the first array of tips <NUM> has been pushed away from the hand-piece (<FIG>), it is optionally allowed to fall into a compartment <NUM>, which optionally enables a disposal of used arrays of tips (<FIG>).

<FIG> also depicts a second array of tips <NUM>, such as for example a gold plated array of tips <NUM>, which is optionally held waiting to be used. Once the first array of tips <NUM> have been dropped into the <NUM>, the extension rod <NUM> is optionally pulled back by the mechanism <NUM> in a reverse direction (<FIG>).

In some embodiments a mechanism for pulling may be a separate mechanism from the mechanism <NUM> for pushing.

Once the extension rod <NUM> is back in its original position, the second array of tips <NUM> is optionally let fall (<FIG>). The mechanism <NUM> optionally starts to work as a pushing mechanism, which pushes the second array of tips <NUM> to its location in contact with in the hand-piece <NUM> (<FIG>).

The hand-piece <NUM>, loaded with the second array of tips <NUM>, is ready to be removed from the console <NUM> and potentially treat a new patient (Figures <NUM>, <NUM>, 14I).

Reference is now made to <FIG>, which is a simplified line drawing illustration of a mechanism for changing an array of tips according to another example embodiment of the invention.

In some embodiments, operation of the mechanism for changing an array of tips is controlled in several ways, including by manual control, by motorized control which may be manually activated or activated by control from a control panel, and by a microprocessor.

<FIG> depicts a hand-piece <NUM> with a transparent distal gauge <NUM> placed on top of a changing mechanism <NUM> for an array of tips. The array of tips is optionally held in place in the treatment hand-piece <NUM> by a spring which pushes the array of tips against a surface. By pressing the spring, its pushing action is stopped and the array of tips may slide horizontally while being pushed linearly by a motor <NUM>.

The holder of the array of tips optionally includes a lever with a pin. A rotation of a rotary solenoid <NUM> optionally rotates a sliding ring <NUM> by a desired angle. The rotation of the sliding ring optionally activates a mechanism <NUM>, which optionally releases the array of tips from its place in the treatment hand-piece <NUM>. Once released, the array of tips is optionally attached to a sliding track and may be driven out of the hand-piece <NUM> by the motor1406. The sliding ring <NUM> is optionally built as a cam which releases the array of tips as well as attaches the array of tips to the sliding track, optionally without additional control.

A holder <NUM> for the array of tips optionally holds a new array of tips, which optionally replaces the used array of tips. The new array of tips is optionally placed on a sterile holder which potentially stays sterile since there is no human contact.

In some embodiments the motor <NUM> is a linear motor.

In some embodiments the motor <NUM> includes a linear encoder.

Reference is now made to <FIG>, which is a simplified line drawing illustration of a mechanism for quick change of an array of tips according to another example embodiment of the invention.

<FIG> depicts a hand-piece <NUM> placed in an opening of a tip array changing mechanism <NUM>. A new tip array <NUM> will replace an old tip array <NUM>. The old tip array may be hot, even up to a temperature of approximately <NUM> degrees C. A motor <NUM>, which optionally includes a rotary encoder to determine position, moves a screw <NUM> which slides tip the old tip array <NUM> using a track <NUM>. An optional cylindrical element <NUM> may optionally releases the old tip array <NUM> prior to the process of discarding the old tip array <NUM>, and an element <NUM> may optionally fix the new tip array <NUM> following placement of the new tip array <NUM> in the hand-piece <NUM>.

In some embodiments, a console unit optionally includes a tip inspection device. The tip inspection device optionally includes a light source, which optionally measures reflection from a surface of an array of tips, and/or an infrared radiometer which measures infrared emission from the surface of the array of tips.

In some embodiments, infrared emission from the surface should not be higher than a preselected value such as <NUM>% emissivity.

In some embodiments the inspection mechanism includes a camera.

Reference is now made to <FIG>, which is a simplified block diagram of a console unit according to an example embodiment of the invention.

As explained above, patient treatments are typically performed at high temperatures, which may attain temperatures above <NUM> deg C. Under such circumstances, safety should optionally be considered and technically applied.

For example, when momentarily pausing a treatment, the hand-piece should optionally be placed in such a way that an operator is prevented from accidentally touching the high temperature array of tips.

For example, while changing tips from a used tip to a new tip, an action which in a preferable embodiment should be rapid, the tip change should be carried out while the tips are still hot, without waiting for a tip to cool.

For example, a used array of tips is preferably disposed of, since the used tips may not be clean, and the used tips may be made of copper which requires disposal.

<FIG> depicts a console <NUM> which includes openings <NUM> thorough which treatment hand-piece(s) or arrays of tips may optionally be introduced. The console <NUM> optionally also includes one or more of: a control panel <NUM>; an array of tips changing unit <NUM>; an array of tips cleaner device <NUM>; a tip inspection unit <NUM>; a suction pump <NUM> which may optionally be connected to a treatment hand-piece through a hose; a microprocessor <NUM> which may optionally control one or more of the control panel <NUM>, array of tips changing unit <NUM>; the array of tips cleaner device <NUM>, and the tip inspection unit <NUM>.

In some embodiments the console <NUM> also includes a power supply <NUM> and/or a <NUM>/<NUM> V mains connection <NUM>.

Example <NUM>: In addition to skin treatments mentioned above, the heated gold-coated pyramidal tips can be advantageous in a broad range of surgical applications. The heated gold-coated pyramidal tips can replace CO2 laser treatments in many cases.

A capability of precisely controlling vaporization depth in receding or flexible tissue enables substantial improvement of state of the art surgery of thin body walls.

Non-limiting examples of such thin and flexible tissues include: a tympanic membrane, which is approximately <NUM>-<NUM> micron thick; walls of fallopian tubes; and vocal cords. These tissue walls, or membranes, are typically treated with focused pulsed CO<NUM> lasers, causing little peripheral thermal damage. In the above cases, in addition to using an expensive laser, (single mode, and very short pulse duration) there is also a need for a focusing beam manipulator, which is uncomfortable to a user and to a patient, and is time consuming (finding the focal position).

In some embodiments, a high temperature tip at <NUM>-<NUM> deg C is used for vaporization of a crater in such walls or membranes, as described in above-mentioned published <CIT>. Published <CIT> still requires a way to let the high temperature tip to reach the surface of the membrane and control depth of penetration with high accuracy, for instance using an optical focusing method.

Using an example embodiment, it is now easier to treat the membranes. During an advance of a high temperature tip toward the membrane, the linear motor which controls the tip advance senses the arrival of the tip at the membrane surface, since mechanical impedance becomes larger. Since the position of the tip is known with an accuracy of ~ <NUM>-<NUM> microns, the motor may receive instructions whereby it advances the tip to a preselected distance, such as <NUM> microns, and immediately reverse the tip advancement. As a result, high quality drilling or incisions are made possible without a need for depth measurement using focusing optics. The tip is optionally inserted in an endoscope, for example in a case such as treatment of a fallopian tube, or in an otoscope such as in the treatment of a tympanic membrane, or in a hand-piece such as in the treatment of vocal cords.

In some embodiment, the high temperature tips are optionally applied to tissue in pulses, optionally at a high frequency, such as from <NUM> - <NUM>. While sensing mechanical compliance of tissue in receding tissue or in tissue covering a bone, it is possible to use a fast mechanical compliance sensing mode, such as every <NUM> milliseconds, or a slower mechanical compliance sensing mode such as every <NUM> milliseconds. In some embodiments sensing the mechanical compliance is performed practically continuously.

A high repetition mechanical compliance sensing mode may potentially be advantageous in several cases.

In some embodiments, by operating a tip at a frequency such as <NUM>, that is advances and retractions of a tip or array of tips per second, and at the same time advancing with the tip/array, a row of craters may be produced.

In some embodiments, by advancing at a speed which enables some overlap of craters, an incision is optionally produced.

In some embodiments, by repeating a process of producing an incision, further depth of the incision is attained and incision of a full thickness tissue is optionally achieved. It is noted that in some embodiments, it is possible to provide a clean way to incise fallopian tubes without bleeding, or with much reduced bleeding, and with minimal or reduced peripheral damage.

In some embodiments a linear array of tips, such as <NUM> row of tips by <NUM> tips per row, which advances and retreats at a high frequency such as <NUM>, is translated across skin during treatment. An example movement velocity may be <NUM> microns within <NUM> milliseconds, which translates to <NUM>/sec. An example distal width of the tips is <NUM> microns. As an example result, lines of <NUM> craters are sequentially produced at a distance of every <NUM> microns. If the hand-piece is translated as described for <NUM> seconds, a large area of <NUM> craters by <NUM> craters at a high density is generated, with the craters separated by <NUM> microns in the direction of motion.

Incising adhesions is typically performed to solve a common surgical problem. The incising is presently commonly performed laparoscopically by electrosurgery. However electrosurgery poses some risks of burn. A potential risk is an accidental return of electric current to ground through a body organ, resulting in a burn. Incision of adhesions with a CO<NUM> laser is also often risky since a multiple section articulate arm which is part of the CO<NUM> laser device is often not well aligned. Long term angular beam alignment accuracy of <NUM> milliradian is generally considered technologically challenging, and misalignment is a reason of many service calls. With a <NUM> meter long articulate arm the potential misalignment can translate into a <NUM> invisible CO<NUM> laser beam position inaccuracy on a tissue target. In many laparoscopic incisions such accuracy is unacceptable. Furthermore, a <NUM> milliradian inaccuracy may cause an edge of the laser beam to be reflected from endoscope walls and to be focused on an unpredictable site. This may result in a requirement for mechanically very stable and expensive articulated arms. An endoscopic heated tip according to some embodiments of the invention, which vibrates and is translated along an adhesion, potentially makes an incision by acting as a safe knife. The position of the cutting tip on the tissue is directly observed, as opposed to the position of an invisible laser beam. The benefit of safety is provided also as a result of at least one of several features described above, such as using a value for skin compliance for open loop control, and/or using a measured depth into tissue based on measuring distance beyond a start of tissue impedance for closed loop control. An operator advances the tip toward contact with tissue, for example tissue such as the fallopian tube wall, optionally using laparoscope viewing optics, and controls incising optionally using as feedback measurement of mechanical compliance or resistance. The operator optionally places a heated tip at the right position, posing no surgical risk, including no burn risk.

It is expected that during the life of a patent maturing from this application many relevant tip and tip coating materials will be developed and the scope of the terms tip and tip coating are intended to include all such new technologies a priori.

The terms "comprising", "including", "having" and their conjugates mean "including but not limited to".

The term "consisting of" is intended to mean "including and limited to".

For example, the term "a unit" or "at least one unit" may include a plurality of units, including combinations thereof.

The words "example" and "exemplary" are used herein to mean "serving as an example, instance or illustration". Any embodiment described as an "example or "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments.

Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub-ranges as well as individual numerical values within that range. For example, description of a range such as from <NUM> to <NUM> should be considered to have specifically disclosed sub-ranges such as from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM>, from <NUM> to <NUM> etc., as well as individual numbers within that range, for example, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>.

Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the invention.

Claim 1:
A device (<NUM>) for producing an array of thermal micro-depressions (<NUM>) in skin (<NUM>) having a controlled distance (<NUM>), comprising:
at least one heated tip (<NUM>), for producing said array of thermal micro-depressions;
a controller (<NUM>); and
a closed loop advancing and retracting mechanism (<NUM>), coupled with said at least one heated tip and said controller, for pushing said at least one heated tip towards skin and for retracting said at least one heated tip from skin;
said closed loop advancing and retracting mechanism comprising a position encoder (<NUM>) for providing feedback to said closed loop advancing and retracting mechanism,
wherein said position encoder and said controller are for controlling a position of said at least one heated tip within skin;
characterized in that said closed loop advancing and retracting mechanism detects contact of said at least one heated tip with skin; and
wherein said closed loop advancing and retracting mechanism advances said at least one heated tip in skin to said controlled distance according to said position encoder and said controller controlling a position of said at least one heated tip when said closed loop advancing and retracting mechanism detects contact of said at least one heated tip with skin.