Method and apparatus for light-based hair removal using incoherent light pulses

1 192784/2

METHOD AND APPARATUS FOR LIGHT-BASED HAIR REMOVAL USING

INCOHERENT LIGHT PULSES

FIELD OF THE INVENTION

The present invention relates to methods and apparatus for hair removal usingincoherent light, for example from a flash lamp.

BACKGROUND AND RELATED ART

The present disclosure relates to improved methods and apparatus fordamaging hair follicles (for example, useful for hair removal) using incoherent lightcomprising a plurality of incoherent light pulses.

Selective photothermolysis is a surgical method, introduced by Anderson andParrish in 1983 ("Selective Photothermolysis: Precise Microsurgery by SelectiveAbsorption of Pulsed Radiation", Science, Vol. 220, pp. 524-527), for destroyingcertain diseased or unsightly tissue, on or near the skin, with minimal damage to thesurrounding healthy tissue. The tissue to be destroyed must be characterized bysignificantly greater optical absorption at some wavelength of electromagneticradiation than the surrounding tissue. The method consists of irradiating the target andthe surrounding tissue with pulsed electromagnetic radiation that is preferentiallyabsorbed by the target. Because the target absorbs the incident radiation much morestrongly than the surrounding tissue, the surrounding tissue is usually heatednegligibly.

In the past decade, many laser and flash based devices for removing unwantedhair based on the principle of selective photothermolsis have been introduced into themarket, and to date, this technique is in wide-spread clinical use. During treatment,the skin of the treatment region is irradiated by a beam of light, and the melanin-containing hair follicle absorbs the delivered electromagnetic radiation, resulting in atemperature rise and destruction for the follicle.

Unfortunately, according to this treatment procedure, the light delivered to the treatment region concomitantly heats the nerve-containing melanin-rich epidermis of the patient, and thus, in many clinical situations, light-based hair removal is considered a painful procedure. 2 192784/2

There is a widely recognized need for, and it would be highly advantageous tohave an improved method and apparatus for hair treatment which heats hair folliclesto a sufficient temperature to damage the hair follicles and to facilitate hair removalwhile delivering a minimal amount of thermal energy to the nerve-containingepidermis. This could be useful for meeting a long felt market need for comfortablehair removal.

The following published patent documents provide potentially relevantbackground art: patent numbers US6,485,484; US6,544,259; US5,632,741;US5,752,948; US6,214,034; US6,273,884; US5,683,380; US6,514,243; US5,735,844;US5,595,568; and application publication numbers US2005/0215988;WO2005/079687; US2005/0143792; US2002/0019624.

SUMMARY

Embodiments of the present invention are based, in part, on the surprisingdiscovery that by rapidly delivering a series of low-fluence incoherent light pulses (forexample from a flash lamp) to a treatment region of skin, it is possible to remove hairfrom the treatment region while minimally heating the epidermis.

It is now disclosed for the first time a method of damaging hair follicles in anarea of tissue having a plurality of hair follicles, the method comprising: a) applying,to the area of tissue, electromagnetic energy comprising a plurality of pulses ofincoherent light wherein: i) each said pulse of incoherent light comprises primarilywavelengths within the range between a minimum wavelength value that is at least750 and a maximum wavelength value that is at most 1500; ii) an average pulse fluence of said plurality of pulses is at least a minimum fluence value that is at least 0.5 J/cmA2 and at most a maximum fluence value that is at most 10 J/cmA2; iii) anaverage repetition rate of said plurality of pulses is at least a repetition value that is atleast 1.5 HZ; iv) an average pulse duration of said light pulses is at least 1millisecond.

According to some embodiments, the minimum wavelength value is at least780 nm.

According to some embodiments, the maximum wavelength value is at most 1200 nm. 3 192784/2

According to some embodiments, the maximum wavelength value is at most 1000 nm.

According to some embodiments, at least 75% of incoherent light of the incoherent light pulses has a wavelength in the range.

According to some embodiments, at least 95% of incoherent light of theincoherent light pulses has a wavelength in the range.

In exemplary embodiments, this may be accomplished by using a low pass filterto filter, for example, broadband light. Thus in some embodiments, the source ofincoherent light includes a filter.

According to some embodiments, the average pulse duration of the pulses is atleast 2 milliseconds.

According to some embodiments, the average pulse duration of the pulses is atleast 4 milliseconds.

According to some embodiments, the average pulse duration of the pulses is atmost 10 milliseconds.

According to some embodiments, the average pulse duration of the pulses is atmost 6 milliseconds.

According to some embodiments, the repetition value is at least 2 HZ, or atleast 3 HZ, or at .least 5 HZ, or at least 10 HZ.

According to some embodiments, a product of the average pulse duration (i.e.in seconds) and the repetition value (i.e. in seconds-1) is at least 0.01, or at least 0.015

According to some embodiments, a product of the average pulse duration (i.e.in seconds) and the repetition value (i.e. in seconds-1) is at most 0.04, or at most 0.03,or at most 0.025.

According to some embodiments, at least 3 pulses (or at least 5 pulses, or atleast 15 pulses, or at least 30 pulses) are applied at the average repetition rate.

According to some embodiments, an average power density per square centimeter of the applied electromagnetic energy is at least a minimum average power density value that is at least 5 Watts/cmA2.

According to some embodiments, the minimum average power density value is at least 10 Watts/cmA2.

According to some embodiments, the average power density is at least the minimum average power density value during a time period when at least 3 pulses are applied at the average repetition rate. 4 192784/2

According to some embodiments, the average power density is at least the minimum average power density value during a time period when at least 5 pulses are applied at the average repetition rate.

According to some embodiments, the average power density is at least theminimum power density value during a time period when at least 15 pulses areapplied at the average repetition rate.

According to some embodiments, the average power density is at least theminimum power density value during a time period when at least 30 pulses areapplied at the average repetition rate.

According to some embodiments, the average power density is at least theminimum power density value during a time period that is at least 1 second.

According to some embodiments, the average power density is at least theminimum power density value during a time period that is at least 2 seconds.

According to some embodiments, the average power density is at least theminimum power density value during a time period that is at least 3 seconds.

According to some embodiments, an average power density of the applied electromagnetic energy is at least at most a maximum power density value that is at most 40 Watts per cmA2.

According to some embodiments, the maximum power density value is atmost 25 Watts per cmA2.

According to some embodiments, the average power density is at most themaximum power density value during a time period that is at least 1 second.

According to some embodiments, the average power density is at most themaximum power density value during a time period that is at least 2 seconds.

According to some embodiments, the average power density is at most themaximum power density value during a time period that is at least 3 seconds.

According to some embodiments, an average power of the appliedelectromagnetic energy is at least a minimum average power value that is at least 50Watts.

According to some embodiments, the minimum average power value is at least 75 Watts.

According to some embodiments, the average power is at least the minimum average power value during a time period when at least 3 pulses are applied at the average repetition rate. 5 192784/2

According to some embodiments, the average power is at least the minimum average power value during a time period when at least 5 pulses are applied at the average repetition rate.

According to some embodiments, the average power is at least the minimumpower value during a time period when at least 15 pulses are applied at the averagerepetition rate.

According to some embodiments, the average power is at least the minimumpower value during a time period when at least 30 pulses are applied at the averagerepetition rate.

According to some embodiments, the average power is at least the minimumpower value during a time period that is at least 1 second.

According to some embodiments, the average power is at least the minimumpower value during a time period that is at least 2 seconds.

According to some embodiments, the average power is at least the minimumpower value during a time period that is at least 3 seconds.

According to some embodiments, an average power of the appliedelectromagnetic energy is at least at most a maximum power value that is at most 250Watts.

According to some embodiments, the maximum power density value is atmost 150 Watts.

According to some embodiments, the average power is at most themaximum power value during a time period that is at least 1 second. 50) According to some embodiments, the average power is at most the maximum power value during a time period that is at least 2 seconds. the average power is at most the maximum power value during a time period that isat least 3 seconds.

According to some embodiments, an average repetition rate of the pluralityof pulses is at most a repetition value that is at most 25 HZ.

According to some embodiments, an average repetition rate of the pluralityof pulses is at most a repetition value that is at most 15 HZ.

According to some embodiments, maximum average fluence value is at most 8 J/cmA2.

According to some embodiments, the maximum average fluence value is at most 6 J/cmA2. 6 192784/2

According to some embodiments, a ratio between a pulse fluence standard deviation of the plurality of pulses and the average pulse fluence of the plurality of pulses is at most a standard deviation ratio that is at most 0.5.

According to some embodiments, the standard deviation ratio is at most 0.2.

According to some embodiments, the applied electromagnetic radiation iseffective to heat the sub-dermal layer of the skin region to a minimum temperaturethat is least 42 degrees.

According to some embodiments, the minimum temperature is at least 45degrees.

According to some embodiments, the applied electromagnetic radiation iseffective to heat the sub-dermal layer of the skin region to a maximum temperaturethat is most 50 degrees.

According to some embodiments, a peak power of the appliedelectromagnetic energy is at most a maximum peak power value that is at most 10,000Watts.

According to some embodiments, the maximum peak power value is at most6,000 Watts.

According to some embodiments, a peak power of density the applied electromagnetic energy is at most a maximum peak power density value that is at most 1,500 Watts per cmA2.

According to some embodiments,the maximum peak density power value is atmost 1,250 Watts.

According to some embodiments, a spot area of the incoherent light isbetween 2 cmA2 and 10 cmA2.

According to some embodiments, a spot area of the incoherent light isbetween 3 cmA2 and 7 cmA2.

According to some embodiments, a ratio between the average pulse fluenceand the average repetition rate of the plurality of pulses is at most a maximum ratiovalue that is at most 3 (J*s)/cmA2;

According to some embodiments, the maximum ratio value is at most 2.5 (J*s)/cmA2.

According to some embodiments, the maximum ratio value is at most 2 (J*s)/cmA2. 7 192784/2

According to some embodiments, the maximum ratio value is at most 1.5 (J*s)/cmA2.

According to some embodiments, the maximum ratio value is at most 1 (J*s)/cmA2.

According to some embodiments, a ratio between the average pulse fluenceand the average pulse duration is at most a maximum ratio value that is at most 1.5 J/(cmA2*ms).

According to some embodiments, the maximum ratio value is at most 1 J/(cmA2*ms).

According to some embodiments, the maximum ratio value is at most 0.75 J/(cmA2*ms).

According to some embodiments, the area of tissue has a size that is at least 2cmA2 and at most 1000 cmA2.

According to some embodiments, step of applying the pulses of coherent lightcomprises generating the coherent light pulses using a flash lamp.

According to some embodiments, the electromagnetic radiation is deliveredfrom an applicator located above a surface of the area of tissue such that there is a gapbetween a lower surface of the applicator and the surface of the area of tissue.

According to some embodiments, the electromagnetic radiation is deliveredfrom an applicator comprising: i) a transparent delivery surface; and ii) a spacerhousing, the applicator configured such that upon engagement of applicator to thesurface of the area of tissue, the transparent delivery surface is above a surface of thearea of tissue.

According to some embodiments, , where the application of theelectromagnetic energy comprising the plurality of pulses is carried out using anapplicator moving over the surface of the area of tissue for at least a minimumapplicator distance that is at least 2 cm at an applicator velocity that is at least aminimum applicator velocity value that is at least 1 cm/sec and that is at most amaximum applicator velocity value that is at most 20 cm/sec.

According to some embodiments, the minimum applicator distance is at least 3 cm.

According to some embodiments, the minimum applicator velocity is at least 2 cm/sec. 8 192784/2

According to some embodiments, the minimum applicator velocity is at least 3.5 cm/sec.

According to some embodiments, the maximum applicator velocity is at most.10 cm/sec.

According to some embodiments, the maximum applicator velocity is atmost.7 cm/sec.

According to some embodiments, the method further comprises: b) cooling atleast a portion of the tissue.

According to some embodiments, the applying of the electromagnetic energyis carried out without cooling the area of tissue.

According to some embodiments, the applying comprises: i) establishing an energy phase a given region having a surface area of 2 cmA2 is subjected the appliedelectromagnetic energy comprising the plurality pulses applied at the averagerepetition rate; and ii) immediately after the energy phase, establishing, for the givenregion, a resting phase having a duration that is at least 2 seconds and at most amaximum resting phase duration that is at most 60 minutes such that during theresting phase, an average power of applied electromagnetic energy having awavelength of at least 750 nm and at most 1500 nm applied to the area of tissue is atmost 30 watts; iii) immediately after the resting phase, repeating steps (a) and (b) tothe given region of tissue at least M times, M being an integer whose value is at leastone.

According to someseconds.

According to someseconds.

According to someseconds.

According to someminutes.

According to someminutes. embodiments, the resting phase duration is at least 10 embodiments, the resting phase duration is at least 30 embodiments, the resting phase duration is at least 90 embodiments, the resting phase duration is at most 10 embodiments, the resting phase duration is at most 5

According to some embodiments, M is at least 2.

According to some embodiments, M is at least 3. 9 192784/2

According to some embodiments, for each the energy phase of a plurality of the resting phase, a cumulative applied energy density of the applied electromagnetic energy for the each energy phase is at least 20 joules/cmA2 and at most 200 joules/cmA2 times within a time period that is at most 20 minutes.

According to some embodiments, the electromagnetic energy comprising thepulses are applied to light colored skin.

According to some embodiments, the electromagnetic radiation comprisingthe pulses is applied to tissue containing low-melanin hair so as to damage the low-melanin hair.

According to some embodiments, the electromagnetic radiation comprisingthe pulses is applied to skin of Fitzpatrick type 1-3 so as to damage hair associatedwith skin of Fitzpatrick type 1-3.

According to some embodiments, the electromagnetic radiation comprisingthe pulses is applied to skin of Fitzpatrick type 4-6 so as to damage hair associatedwith skin of Fitzpatrick type 4-6.

According to some embodiments, the electromagnetic radiation is applied tothe tissue so as to damage low-melanin hair associated with the tissue.

It is noted that a number of treatment protocols are disclosed herein. It isunderstood that any device or apparatus that is configured to carry out any of thepresently disclosed treatment protocols is within the scope of the present invention.

Thus, in one example, it is now disclosed for the first time an apparatus fordamaging hair follicles in an area of tissue having a plurality of hair follicles, theapparatus comprising: a) an incoherent light source operative to generate incoherentlight comprising a plurality of incoherent light pulses, each said pulse of incoherentlight comprising primarily wavelengths within the range between a minimumwavelength value that is at least 750 nm and a maximum wavelength value that is atmost 1500 nm; and b) a controller operative to at least partially control pulsecharacteristics of said light pulses, said source and said controller being configuredsuch that: i) an average pulse fluence of said plurality of pulses is at least a minimumfluence value that is at least 0.5 J/cmA2 and at most a maximum fluence value that isat most 10 J/cmA2 (or, for example, 8 J/cmA2 or 6 J/cmA2); ii) an average repetitionrate of said plurality of pulses is at least a repetition value that is at least 1.5 HZ (orfor example, 3 HZ or 5 HZ or 7 HZ); iii) an average pulse duration of said light pulsesis at least 1 millisecond. 10 192784/2

These and further embodiments will be apparent from the detailed description and examples that follow.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A-1C provide block diagrams of exemplary apparatus for damaging hairfollicles with electromagnetic radiation in accordance with some embodiments of thepresent invention. FIG. 2 provides a block diagram of an exemplary control unit. FIG. 3 provides a block diagram of an exemplary pulsed-light source FIG. 4A provides a block diagram of an exemplary treatment region. FIG. 4B provides a block diagram of an exemplary technique for treating various sub-regions of a treatment region. FIG. 5 provides a flow chart diagram of an exemplary procedure for treating a givenlocation or area of tissue such as skin.

While the invention is described herein by way of example for severalembodiments and illustrative drawings, those skilled in the art will recognize that theinvention is not limited to the embodiments or drawings described. It should beunderstood that the drawings and detailed description thereto are not intended to limitthe invention to the particular form disclosed, but on the contrary, the invention is tocover all modifications, equivalents and alternatives falling within the spirit and scopeof the present invention. As used throughout this application, the word “may” is usedin a permissive sense (i.e., meaning “having the potential to'), rather than themandatory sense (i.e. meaning “must”).

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention will now be described in terms of specific, exampleembodiments. It is to be understood that the invention is not limited to the exampleembodiments disclosed. It should also be understood that not every feature of thepresently disclosed apparatus and method for thermally damaging hair follicles isnecessary to implement the invention as claimed in any particular one of the appendedclaims. Various elements and features of devices are described to fully enable the 11 192784/2 invention. It should also be understood that throughout this disclosure, where a process or method is shown or described, the steps of the method may be performed in any order or simultaneously, unless it is clear from the context that one step depends on another being performed first.

Introduction and Theoretical Discussion

Embodiments of the present invention are based, in part, on the surprisingdiscovery that by rapidly delivering a series or plurality of low-fluence light pulses (forexample pulses of incoherent light from a flash lamp) to a treatment region of skin, it ispossible to effectively damage hair follicles in the treatment region while minimally heating the epidermis. It is noted that the aforementioned hair follicle-damagingtechnique may be useful for safely facilitating the removal of hair from the treatmentregion of skin.

In particular, and not wishing to be bound by theory, it is noted that eventhough each individual incoherent light pulse may be a relatively ‘low fluence' lightpulse, the rapidly-delivered plurality of low-fluence pulses, collectively may provideenough average power over enough time to heat the thermally-conductive sub-dermallayer or dermis to a sufficient temperature (for example, at least 42 degrees or at least45 degrees) to damage hair follicles to an extent necessary to facilitate hair removal.By providing rapid delivery of low fluence pulses rather than pulses of greater fluence(i.e. delivered at a lower repetition rate), it may be possible to damage the hairfollicles with less pain and/or less required cooling and/or in a safer protocol and/orwith less concomitant heating of the nerve-containing epidermis.

Once again not wishing to be bound by theory, it is postulated that because thedermis is a good heat conductor, when the pulses are rapidly delivered at the ‘highrepetition rate,' (i) the temperature of the hair follicle does not drop below thetemperature of the heated dermis (i.e. the heated-dermis temperature) for a period oftime long enough to damage the hair follicle (ii) this heat damaging of the hairfollicle is useful for facilitating hair removal.

It is noted that it may be useful to use light in a certain range of wavelengths in order to heat and damage hair follicles (i.e. in a manner useful for hair). Thus, in some embodiments, the optical radiation of the rapidly-delivered low-fluence pulses includes light in the “optical window” having a wavelength of between 750 nm and 1500 nm (or between 780 nm and 1000 nm), which penetrates below the epidermis 12 192784/2 and to deliver energy to the sub-dermal tissue layer (i.e. the dermis) below the epidermis.

Not wishing to be bound by theory, it is noted that light in this ‘opticalwindow' may heat the epidermis less than light, for example, in the range between650 nm and 700 nm or other ranges. Thus, rather than by relying exclusively onselective photothermolysis to heat the melanin rich hair follicle, it is possible to usethe chromophores in the surrounding tissue as ‘reservoirs' to effectively heat up anddamage the hair follicle.

In some embodiments, one or more of the following features may be providedwhen applying the plurality of incoherent light pulses (for example, filteredbroadband light): i) a ‘low' average fluence (i.e. averaged over individual pulses) of the rapidly-delivered plurality of light incoherent pulses that is at most 10 J/cmA2 per pulse, or at most 8 J/cmA2 per pulse or at most 6 J/cmA2 perpulse; ii) a ‘high repetition rate' - for example, at least 1.5 HZ, or at least 2HZ or at least 2.5 HZ, or at least 5 HZ, or at least 7.5 HZ. In differentexamples, the lower fluences may be associated with higher reptitionrates. iii) a ‘high average power' (i.e. relative to the low fluence) sustainedover a given period of time needed to thermally damage the hairfollicles (for example, to at least 42 or 45 degrees for at least 0.5seconds or at least 1 second or at least 2 seconds or at least 2.5seconds). In exemplary embodiments, this ‘high' average power maybe at least 35 Watts or at least 50 Watts or at least 75 Watts. Thespecific average power may depend on physiological factors such ashair and/or skin color. iv) a ‘short' pulse width or pulse duration - for example, less than 10milliseconds and greater than 0.5 millisecond or greater than 1millisecond. In some embodiments, the pulse width or duration ofindividual pulses is between 2 and 7 millisecons. 13 192784/2

It is noted that the teachings of the present invention may be used to remove hair from any area of the body, including but not limited to the back, face, head, eyebrows, eyelashes, chest, abdomen, pubic area, legs, and armpits.

Furthermore, it is noted that application or delivery of light, for example oneor more pulses of light, to a given region or sub-region or area of tissue (for exampleskin) refers to application or delivery of the light (for example, one or more pulses oflight) to any location or locations within the region or sub-region of tissue.

Optical Radiation and Pulse Properties

Various embodiments of the present invention provide any combination of thefollowing salient features. It is appreciated that not every one of these followingfeatures must be included in every embodiment. a) Wavelength features. The present inventor is disclosing a treatment anddevice that delivers, to the skin of the patient, optical radiation including “deeper-penetrating” optical radiation which traverses the melanin-rich epidermis and isabsorbed by the sub-dermal tissue (i.e. the dermis). In some embodiments, thisdeeper-penetrating optical radiation comprises light having a wavelength between aminimum wavelength value (for example, 750 nm, for example 780 nm or 800 nm)and an maximum wavelength value (for example 950 nm, or 980 nm , or 1000 nm, or1200 nm 1500 nm). Not wishing to be bound by theory, it is disclosed that choosingwavelengths in the “optical window” may be useful for providing a treatment protocol(or treatment device) that is less likely to heat the nerve-containing epidermis, therebyobviating (but not necessarily eliminating) the need for tedious cooling (appliedconcomitantly, or applied using a “pre-cooling protocol”) and/or thereby providing asafer treatment protocol.

In exemplary embodiments, this is provided by providing light at a plurality offrequencies (for example, light from an IPL device that is filtered with a band-passfilter), such that a majority (or greater) of the of the applied optical radiation has awavelength in a given wavelength range defined by a minimum wavelength value(for example, 750 nm, for example 780 nm or 800 nm) and an maximum wavelengthvalue (for example 950 nm, or 980 nm , or 1000 nm, or 1200 nm 1500 nm).

In some embodiments, the applied incoherent light and/or each pulse thereof comprises ‘primarily' wavelengths within the range defined by the minimum 14 192784/2 wavelength value and the maximum wavelength value - i.e. at least 70% of the incoherent light or each pulses thereof has a wavelength in this range.

In some embodiments, at least 75% of the incoherent light or each pulses thereof has a wavelength in this range.

In some embodiments, at least 90% of the incoherent light or each pulses thereof has awavelength in this range.

In some embodiments, at least 95% of the incoherent light or each pulses thereof has awavelength in this range. b) Fluence features. The present inventor is disclosingthat it is possible toremove hair by applying low-fluence pulses of incoherent light to the skin of a patient.

In exemplary embodiments, the ‘low fluence pulses' have a fluence that is lessthan 10 J/cmA2 per pulse or less than 8 J/cmA2 or less than 6 J/cmA2 .

It is appreciated that when a plurality of series of pulses are applied, not everyindividual pulse necessarily has the same exact fluence, and that there may be somevariation in the fluence between pulses.

In some embodiments, however, every pulse of a given plurality of pulses in arange disclosed for ‘average pulse fluence' - e.g. every pulse has a fluence less than10 J/cmA2, or 8 J cmA2, etc.

It is noted that the specific fluence (as well as other features such as pulsewidth, repetition rate, power, etc) provided may depend on a number of physiologicalfactors, including but not limited to the skin color and hair color. For example, forlighter hair (less “melanized” hair), it may be desirable to choose a larger fluence.Similarly, for darker skin, it may be desirable to choose a smaller fluence.

It is noted that these low-fluence pulses are surprisingly effective for hairremoval. c) Repetition rate features The present inventor is disclosing for the first time,a hair-removal protocol and device where light is applied to the skin with a certain“high” repetition rate.

As used herein, a ‘repetition rate' refers to rate of individual pulses (i.e. inpulses per second, or HZ) delivered over a given time period - the number of pulsesdelivered or delivered or provided divided by the length of ‘given' time period. Indifferent embodiments, the given time period may be, for example, at least 0.5seconds, at least 1 second, at least 1.5 seconds, at least 2 seconds, at least 3 seconds, atleast 5 seconds or at least 10 seconds. 15 192784/2

In exemplary embodiments, the ‘rapid' repetition rate is at least 1.5 pulses / sec, and/or at least 2.5 pulses/ sec and/or at least 2.5 pulses/sec and/or at least 3 pulses/sec and/or at least 7.5 pulses/sec and/or at least 5 pulses/sec.

In some embodiments, the maximum repetition rate is 20 or 15 or 12.5 or 10pulses/sec. In some embodiments, when the repetition rate increases, the selectedfluence is lower. d) Pulse duration/ pulsewidth features. In exemplary embodiments the pulseswidth or duration of individual pulses of incoherent light is, on average, for example,less than 10 milliseconds and greater than 0.5 millisecond or greater than 1millisecond. In some embodiments, the pulse width or duration of individual pulsesis, on average, between 2 and 7 milliseconds.

Once again, is noted that the specific fluence, and also the specific pulse-duration or pulse-width provided may depend on a number of physiological factors,including but not limited to the skin color and hair color. For example, for lighter hair(less “melanized” hair), it may be desirable to choose a longer pulses with a largerfluence. Similarly, for darker skin, it may be desirable to choose shorter pulses with asmaller fluence. e) Relation Between Fluence and Repitition Rate - In exemplaryembodiments, a “rapidly applied series of low-fluence pulses” of light are applied.Thus, in exemplary embodiments, a ratio between an average pulse fluence of theplurality of light pulses and an repetition rate of the plurality of light pulses is at mosta maximum ratio value that is at most 3 (J*s)/cmA2, or at most 2 (J*s)/cmA2, or atmost 1.5 (J*s)/cmA2. f) Average power features.

In some embodiments, a minimum average power is provided (i.e. incoherentand/or coherent light is delivered at a minimum average power), in order to ensurethat the sub-dermal layer (i.e. the dermis) (or portion thereof) is heated above theminimum dermis heated temperature.

For example, a minimum average power of 35 Watts, or 50 Watts, or 75 Watts is provided for a given period of time (i.e. enough time to heat the dermis to at least 42 or 45 degrees Celsius). 16 192784/2

In another example, a minimum average power density of 8 Watts/cmA2, or 12

Watts/cmA2, or 15 Watts/cmA2 is provided for the given period of time.

Not wishing to be bound by theory, it is noted that by operating at a relatively‘high' average power for a certain given period of time (for example, at least 0.5seconds, or at least 1 second, or at least 2 seconds, etc - or a period of time duringwhich a certain minimum number of pulses are delivered - for example at least 3, 5,10, 15 or 30 pulses), it is possible to provide enough power to heat the sub-dermallayer or dermis.

In some embodiments, a maximum average power is provided (and/or amaximum average power of light in certain wavelengths, for example, in order to aprovide a safer treatment and/or a treatment where there is less of a need to cool thedermis. Thus, in exemplary embodiments, the average power is less than 400 Watts,or less than 300 Watts or less than 200 Watts or less than 150 Watts.

Exemplary Treatment Device FIGS. 1A-1C provides block diagrams of exemplary devices in accordancewith exemplary embodiments of the present invention. These figures (and all figures)are intended as illustrative and not as limiting.

The device includes a source of pulsed incoherent light 110 (for example, aflashlamp), a controller 215 (in the specific example of the figures, provided as part ofcontrol unit 116) and an applicator 114.

Applicator 114 is adapted to deliver light to the treatment area of the patient.In some embodiments, applicator 114 includes a housing with an aperture fordelivering the pulses of light. In some embodiments, a control may be provide fordetermining or controlling the applicator size.

It is noted that applicators 114 for delivering optical radiation to skin toremove hair are well-known in the art, and that any known applicator 114 and anyknown applicator feature may be used in the presently-described apparatus for hairremoval.

In some embodiments, the applicator may include and/or be associated some sort of embedded control for example, a button, for controlling the delivered radiation - for example, an ‘on/off' control. 17 192784/2

Although the applicator 114 is shown in contact with the skin (i.e. in contact with the epidermis 52) in FIG. 1A, this is not to be construed as a limitation, and embodiments where light is applied to the skin without touching the skin are also within the scope of the present invention.

In FIG. 1B, the applicator 114 is ‘above' the surface of the skin (i.e. nottouching the skin) such that there is a gap of length d1 between the bottom of theapplicator 114 and the surface of the skin.

In FIG. 1C, the applicator 114 includes a transparent energy delivery element45 through which incoherent light (and optionally other electromagnetic energy) isapplied to the skin surface 49. The energy delivery element 45 is configured in theapplicator 114 such that is a ‘spacer' or ‘gap of length d2 between the lower surface(or energy delivery surface 43) of transparent energy delivery element 45 and the skinsurface.

As shown in FIGS. 1A-1C the control unit 116 includes controller 215 (forexample, either (i) automatic electronic controls for example including amicroprocessor and/or code provided using any combination of software andhardware and/or (ii) manual controls) controls various parameters of theelectromagnetic radiation emitted by the pulsed light source 110.

Thus, it is noted that in the specific example of FIGS. 1A-1C and FIG. 2,controller 215 is provided separately (and in a separate unit) from light source 110and applicator 114. This is not to be construed as a limitation . In some embodiments,the ‘controller' 215 may be configured as an integral part of the light source 110 or asan integral part of a incoherent light device such as a flash device (i.e. including lightsource 110) - i.e. a light source configured inherently to generate the desired pulsesequence. Furthermore, there is no requirement of a separate ‘control unit 116.'

In the example of FIGS. 1A-1C the pulse light source 110 is embedded withinapplicator 114. Alternatively or additionally, in some examples, the pulse light source110 is located outside of applicator 114 and the light is delivered, for example viasome sort of waveguide or conduit, from an ‘external' light source into the applicator 114.

In exemplary embodiments, the 114 applicator is cooled to provide cooling such as contact cooling (for example, contact cooling such as sapphire contact cooling) provided using the applicator. In embodiments related to contact cooling, it may be preferred to provide good thermal contact. 18 192784/2

It is appreciated that although there is no cooling requirement, that any combination of cooling techniques may be used, including pre-cooling, concurrent cooling, spray cooling, gel cooling, air cooling, etc.

In exemplary embodiments, the cooling is applied before and/or during and/orafter treatment with light pulses. In exemplary embodiments, the amount of cooling(for example, contract cooling and/or spray cooling or any other cooling) isdetermined by the control unit 116 (for example, controller 215), for example, inaccordance with one or more parameters of the pulsed light.

In exemplary embodiments, the light penetrates to the dermis 54 to heat thedermis, for example, to at least 42 degrees or at least 45 degrees Celsius. Inexemplary embodiments, the hair follicle 50 is heated to a greater temperature thanthe temperature of the dermis, for example, to a thermal denaturation temperature,though this is not a requirement and it may be possible to damage hair follicleswithout necessarily heating the follicles to a denaturation temperation.

Not wishing to be bound by theory, it is noted that in exemplary embodiments,because of the warm temperature of the dermis, the hair follicle does not cool belowthe temperature of the dermis for a certain period of time.. When this happens, thehair can be removed, for example, by waiting for the hair to shed and/or with atweezer, etc.

In some embodiments, the heated region of dermis (or sub-dermal layer) as anarea that is at least 20% or at least 50% or at least 80% any spot area disclosed hereinand is heated for a minimum period of time - for example, at least 0.5 second, at least1 second, at least 2 seconds, or any other period of time useful for achieving thedesired heating of the hair follicles (and thermal damage of the hair follicles). FIG. 2 provides a block diagram of an exemplary control unit 116. As notedearlier, various parameters may be determined either manually by the operator and/ormay be computed using electronic circuitry. It may, nevertheless, be convenient toprovide certain ‘pre-programmed options.'

Control unit 116 of the example of FIG. 2 includes controller 215. Controller215 is operative to at least partially control one or more pulse characteristics includingbut not pulse fluence, duration of individual pulses (i.e. pulse width), powerparameters (for example, average and/or peak power), duration of a pulse sequence,number of pulses in a pulse sequence, and pulse rate. 19 192784/2

Thus, in the example of FIG. 2, controller 215 includes one or more of: a repetition rate selector 210, fluence selector 212, individual pulse duration (or pulse width) selector 217, power selector 214 (for determining, for example, peak power and/or average power and/or a derived parameter of the two), and a pulse sequence duration selector and/or number of pulses in a pulse sequence selector 213.

Thus, in different embodiments, controller 215 may be operative orprogrammed to provide a certain pulse sequence comprising at least a minimumnumber of pulses (for example, at least 3 pulses, at least 5 pulses, at least 10 pulses, atleast 15 pulses or at least 30 pulses) at a given repetition rate.

In some embodiments, the control unit 116 is ‘pre-configured' to provide aselected treatment protocol for hair removal (for example, any treatment protocoldescribed describing repetition rate and/or fluence of light pulses and/or pulse width ofpulse duration and/or power parameters) described herein. In one example, the user mayselect a given treatement protocol (for example, a presently disclosed protocol) from aplurality of protocols using some sort of used interface (not shown) that utilizes display 216.

In some embodiments, more than one ‘program' associated with a given pulsesequence is provided, and a mechanism for selecting a specific program is provided.In one particular example, a user interface for selecting a specific program inaccordance with skin and/or hair color is provided.

For example, a ‘light skin' program may provide higher fluence pulses, whilea ‘lower skin' program may provide lower fluence pulses, but, for example, a higherrepetition rate.

In exemplary embodiments, the control unit includes a user display forexample, useful for selecting a program.

It is noted that in some embodiments, a user may specify a first parameter orset of parameters (for example, a fluence) and controller 215 may determine orcalculate another parameter (for example, repetition rate) from the specified parameteror parameters.

It is noted that as depicted in the figures, the light source 110 is ‘embedded' in the applicator (for example, handpiece). This salient feature is provided by certain embodiments, though this is not to be construed as a limitation.

In exemplary embodiments, one or more user input controls (for example, keyboard, foot pedal, etc) (not shown) may be provided. 20 192784/2 FIG. 3 provides a diagram of an exemplary light source 110 (i.e. source of pulsed and/or CW light). In the example of FIG. 3, this includes a pulse generator 310 (for example, controlled by the device control unit), a light source 312 (for example an incoherent light source such a flash lamp), and an optics assembly 314.

Optics assembly 314 may be configured to modify propagation of theelectromagnetic radiation of the incoherent light - for example, to direct light in apre-determined direction and/or to a predetermined location. Optics assembly mayinclude any appropriate optical components known to one skilled in the art forperforming this function, including but not limited to wave guides, lenses (i.e.including but not limited to refractive and diffractive lenses), and mirrors. Optionally,in some embodiments related to incoherent light-based hair removal, optics assembly314 may include a band pass filter, for example, a low-pass filter for filteringincoherent light from the flashlamp.

The flash lamp or other incoherent light source may be programmed toprovide light of different ranges of wavelengths.

It is noted that there is no limitation on the shape of the light pulse. In exemplaryembodiments, the shape of the pulse is square, though this is certainly not a limitation,and pulses of any shape (for example, sinosiodal, sawtooth, etc) are within the scopeof the present invention.

In exemplary embodiments relating to incoherent light, the spot area or spotsize is between, for example, 3 cmA2 and 10 cmA2 - for example, between 3 cmA2and 7 cmA2.

In some embodiments, the inter-pulse time is maintained constant.Alternatively, this parameter may be varied, providing varying repetition rates.

One salient feature provided in some embodiments by the control unit, is thatthe pulses of light may be of different predetermined optical radiation and/or pulseparameters, for example, predetermined wavelengths, fluence, repetition rate, pulseshape, etc.

It is noted that in some embodiments, electromagnetic radiation other thanoptical radiation (for example, RF radiation) may be applied concomitantly with thepulses of light. Nevertheless, this is not a limitation, and embodiments where the totalintensity of this non-optical energy is at most 10% of the total electromagneticradiation intensity are within the scope of the present invention. Typically, no RF 21 192784/2 radiation is applied, and only light (coherent and/or incoherent) is applied, though this is not to be construed as a limitation.

As noted above, various parameters may optionally varied in time, for example, repetition rate, pulse shape, pulse width, etc.

It is noted that in various embodiments, the electromagnetic radiationincluding the light pulse is applied so as to remove the hair (temporary and/orpermanent hair removal) without burning the surrounding tissue/skin and/or leaving the surrounding tissue/skin free of injury.

Additional Discussion About Treatment Protocols

In some embodiments, the treating of the patient comprises the steps: (i) identifying a region of the patient where hair follicles are present (or a region fromwhich it is desired to damage hair follicles; (ii) apply the electromagnetic radiationcomprises a plurality of incoherent light pulses; (iii) allow the hair follicles to bedamaged by the applied electromagnetic radiation.

Handpiece or Applicator Speed

Not wishing to be bound by any theory, it is noted that use of a relatively‘high' pulse delivery rate or frequency allows for application of light pulses via ahandpiece that moves over the surface of the skin at a relatively ‘high' velocity. Thisis because more individual pulses are delivered in a given period of time when thepulse delivery rate is higher, and thus, even the handpiece speed is relatively ‘high,' agiven hair follicle may still receive a minimum number of pulses.

In exemplary embodiments, on average, each hair follicle within a giventreatment region (for example, a given treatment region of at least 1 cmA2, or at least5 cmA2, or at least 10 cmA2, or at least 50 cmA2) receives between 10 and 15 pulses. Itis recognized that depending on the specific application, there are some clinicalsituations where, for example, a given follicle is subject to at least 5 pulses, at most 20pulses or any other number of pulses.

In some embodiments, the application of the plurality of light pulses is carriedout via an applicator or handpiece (for example, an applicator that concomitantlyprovides cooling including but not limited to contact cooling) that moves or ‘glides'over the surface of the treatment surface (i.e. over the surface of the skin) at a velocitythat is, on average, at least 3 cm/sec (or at least 4 cm/sec, or approximately 5 cm/sec)during the time period that the plurality of light pulses are delivered at a given 22 192784/2 minimum average repetition rate (for example, during a time period where at least 10 pulses are delivered, or a time period that at least 20 pulses are delivered, or a time period that at least 50 pulses are delivered, or a time period that at least 75 pulses are delivered, or a time period a that at least 100 pulses are delivered.

As used herein, the ‘velocity' of an applicator or handpiece refers to thevelocity of a fixed point on the applicator or handpiece (for example, a center of mass,or in another example, a fixed point on an energy treatment surface) relative to thetreatment region or skin as the applicator or handpiece moves over the surface of thetreatment region or skin (for example, parallel to the local plane of the treatmentregion).

It is recognized that in different applications, the minimum or average velocity of the handpiece required during application or delivery of the light pulses may vary depending on the application - i.e. depending on parameters such as the repetitionrate, the spot area, the level of aggressiveness of treatment required, etc.

Thus, in one example, if the repetition rate is higher, it is possible to deliverthe light pulses from a handpiece or applicator having a higher velocity during thetime of pulse delivery. In another example, a greater spot area will also allow a higherhandpiece or applicator velocity.

In some embodiments, the average handpiece velocity during the time of pulsedelivery (i.e. of incoherent light pulses) is at least 3 cm/sec, at least 4 cm/sec, or about5 cm/sec. In some embodiments, the average handpiece or applicator velocity v isdetermined such that the ratio (72)/[(freq)A2*(spofj\ (where v is the velocity of thehandpiece or applicator in cm/sec, spot is the spot area in cmA2) is at least 0.1, or atleast 0.3, or at least 0.5, or at least 0.7 or at least 1, during the time period of deliveryof the plurality of pulses of incoherent light .

Not wishing to be bound by theory, it is noted that in some embodiments, thepractitioner treating the patient for hair removal may elect to employ a ‘faster' or‘higher' velocity in order to provide a faster hair removal treatment.

Sequential Treatments of Sub-Regions of a Treatment Region FIG. 4A provides an illustration of an exemplary treatment region 500. It is noted that each of the sub-regions is a mathematical construct. In the example of FIGS. 4A, each sub-region has a rectangular shape (and the overall treatment region 500 has a rectangular shape), though this is not to be construed as a limitation.

According to the example of FIGS. 4A-4B, the practitioner providing hair-removal 23 192784/2 treatment to the patient applies pulses of light to different areas or sub-regions of the treatment region 500, for example, by moving a handpiece for delivering light pulses across the treatment region.

Thus, the treatment may be applied sequentially. In one particular example,during a course of treatment of treatment region 500, first sub-region ‘A' 502 istreated 511 with a plurality of pulses of light; then first sub-region ‘B' 504 is treated513 with a plurality of pulses of light; then first sub-region ‘C' 506 is treated 515 witha plurality of pulses of light; then first sub-region ‘D' 508 is treated 517 with aplurality of pulses of light; then first sub-region ‘E' 510 is treated 519 with a pluralityof pulses of light.

This process may be repeated any number of times. As shown in FIG. 5A,subscript i indicates the ith time the treatment of a given sub-region is carried out.

In the example of FIGS. 4A-4B, when a given sub-region is being treated,other sub-regions are not being tried (i.e. because the handpiece or applicator is atanother location). Thus, sub-region ‘A' is treated first during time interval t11. Thenduring a ‘resting' time interval including time intervals t21, t31, t41, t51 and , t16 theapplicator is treating other sub-regions (i.e. sub-regions ‘B' through F'). Thus, duringthis ‘resting' time interval, sub-region ‘A' 502 does not receive pulses of light.Subsequently, during time interval , t12 , sub-region ‘A' 502 once again is subjected511 to a plurality of pulses of light.

Thus, the process described in FIG. 5B is one particular example of‘intermittent' application of pulses of light (i.e. each sub-region is intermittentlysubjected to a plurality of light pulses), which is described below.

Intermittent Application of Pulses of Light to a Given Location(s) On the Skin of A

Patient to Facilitate Removal of Hair

In some embodiments, not all pulses are delivered to a given location on theskin or a given hair follicle continuously or at once.

Thus, as described with reference to FIGS. 4A-4B, it is possible that a givenfirst sub-region will be treated with a number of pulses, after which a second sub-region will be treated (for example, by moving the applicator or handpiece from thefirst to the second sub-region, for example, by gliding the applicator over the skin ofthe treated region to reach the second sub-region), after which the first sub-region willreceive additional pulses of light. 24 192784/2

Alternatively or additionally, in another example of ‘intermittent' application of light pulses, a certain number of pulses may be delivered to a certain region, after which, for a period of time, no pulses are delivered to a treatment region (for example, the operate may temporarily stop pulse delivery, for example, using a foot-pedal), after which, once again, a certain number of pulses are delivered.

Furthermore, it is appreciated that in some embodiments, the speed of theapplicator may be a function of the size of the region treated. FIG. 5 provides a flow chart diagram of an exemplary procedure where a given location or area of tissue is intermittently subjected to applied light pulses - i.e.light pulses are applied over a first period of time (step 401), after which, during asecond period of time (step 403) the given location or area of tissue does not receivethe light pulses, after which, during a third period of time (i.e. repetition of step 401),the given location or area of tissue once again is subjected to the applied light pulses.Steps 401 and 403 may repeated any number of times to facilitate removal of hairfrom the given location or area.

Thus, in step 401, a series of light pulses are applied to delivered (i.e.comprising a minimum number of pulses P) at a given repetition rate In one example,these pulses have an average fluence that is less than 8 J/cmA2 per pulse and a least0.5 J/cmA2 per pulse.

As used herein, delivering or applying one or more pulses of incoherent lightto an area or region may include delivering the pulses to one or more locations withinthe area or region.

It is noted in some embodiments, the number of pulses P delivered to the areaor region (i.e. to one or more locations within the area or region) in step 401 dependson the size of the area, where a larger area may receive more pulses due, for example,to the greater ‘capacity' for the larger area to receive pulses at more locations withinthe larger area.

Thus, in one example, if the area of tissue is of size N cmA2 (i.e. has a surfacearea that is N cmA2), the number of pulses delivered in step 401 is at least the smallestinteger that is greater than 1.5 N.

According to this example, the value of N may be in the range between 1 and 20, between 1.5 and 15, between 2 and 15, and in other sub-ranges.

In one specific example, an area of tissue of size 1 cmA2 may receive 2 pulses in a given ‘pass' of the handpiece (i.e. during one instance of step 401). Similarly, in 25 192784/2 this example, an area of tissue of size 4 cmA2 may, in this specific example, receive 8 pulses in a given ‘pass' of the handpiece.

Referring now to step 403, it is noted that after applying the at least P lightpulses, the region or area (which may or may not be a sub-region of a larger treatmentregion) may be subjected to a resting phase where either no light pulses are delivered(i.e. to any location within the region or area) or only light having a reduced averagepower is applied or delivered to the region or area.

During the time period of step 403, the given region or area may be allowed tocool before repetition of step 401. This may be useful for providing a safe treatment.

In one example, where the applicator is applying energy elsewhere during thetime period of step 403, no energy whatsoever need to be applied during the restingphase. This was described in FIGS 4A-4B. Thus, for sub-region ‘A' 502, the firstexecution of step 401 is carried out during time interval t11. The first execution of step403 is carried out during a time interval including time intervals t21, t31, t41, t51 and ,t16. The second execution of step 401 is carried out during time interval t12.

For sub-region ‘B' 502, the first execution of step 401 is carried out duringtime interval t21. The first execution of step 403 is carried out during a time intervalincluding time intervals t31, t41, t51, t16 and t12. The second execution of step 401 iscarried out during time interval t22.

It is noted that in various embodiments, this resting phase may be a ‘no energyapplication phase' or a ‘relatively low application of energy phase.'

In one example, during the ‘resting phase' of step 403, an average power ofthe light (either the total amount of light or the amount of light in the region of thespectrum between 750 nm and 1500 nm) delivered (for example, delivered by thehandpiece or applicator used to deliver, i.e. in step 401, the plurality of light pulses)does not exceed some ‘low power' number - for example, does not exceed, say 30Watts, or does not exceed 20 Watts, or does not exceed 10 Watts, or does not exceed5 Watts.

In different embodiments, the duration of the ‘resting' phase varies, forexample, in accordance with a desired level of aggressiveness of treatment and/or thesize of the overall ‘treatment' region and/or physical parameters of the patient (forexample, hair or skin color) and/or one or more various factors.

The skilled practitioner applying the treatment determine the length of the ‘resting' phase according to a number of examples Thus, in different examples, the 26 192784/2 duration of the ‘resting phase' of step 403 lasts for a minimum time that may dependon one more factors. Thus, for example, a given hair follicle may be subjected to the‘rest phase' for an amount of time that is least a few seconds and at most a period oftime on the order of magnitude of a duration of a hair removal treatment - i.e. at mostsome number of minutes (for example, at most 20 minutes, or 30 minutes or an 60minutes).

In one example, for example similar to the example of FIG. 5A, the length ofthe resting period may be influenced by the size of a given sub-region relative to thesize of an overall treatment region. Thus, if the size of a given sub-region is smallrelative to the size of the overall treatment region, this may increase the length of timeof the ‘resting period' of step 403. If the of a given sub-region is larger relative to thesize of the overall treatment region, this may decrease the length of time of the‘resting period' of step 403

It is noted that the total number of pulses delivered may depend on the size ofthe treatment region 500. In one example, the device may be pre-configured to deliverat least a certain number of pulses (or programmed to deliver any number of pulses),for example, at least 15, at least 30, at least 50, at least 100, and at least 500.Furthermore, in different examples, the user or practitioner providing the hair removaltreatment may have a control to stop deliver of pulses (temporarily or altogether).

The following examples are to be considered merely as illustrative and non-limiting innature. It will be apparent to one skilled in the art to which the present inventionpertains that many modifications, permutations, and variations may be made withoutdeparting from the scope of the invention.

EXAMPLES

Various experiments were conducted by the present inventors to demonstratehuman hair removal by applying optical radiation in accordance with one or moreteachings disclosed herein. In Example 1 , some of the conducted experiments aredescribed. In Example 2, additional exemplary protocols and device configurationparameters are related to incoherent light described. 27 192784/2

Example 1: Hair Removal Using Incoherent Intense Pulsed Light

The present inventor has constructed an exemplary flashlamp hair removaldevice, and has configured this device in accordance with certain teachings of thepresent invention. The present inventor has conducted certain experiments toillustrate hair removal using this aforementioned device.

In the exemplary device, light having a wavelength of less than 780 nm andgreater than 1300 nm was filtered using low-pass filters.

Table 2, shown below, lists various optical fields configuration parameters thatwere used during one particular experiment. During this experiment, a series of squarepulses were applied to the skin, where the time between pulse pairs was equal for allpulse pairs.

Parameter Value

Fluence

Pulse DurationSpot Area

Pulse frequency (rep rate)Peak powerAverage power 5 J/cmA2 6 ms 6.4 cmA2

3 pulses/second5 * 1/0.006*6.4=5,330 W

5 x 6.4 x 3 = 96 W

Example 2: Hair Removal Using Incoherent Intense Pulsed Light

Example 2 describes additional device or treatment non-limiting parameters related toincoherent light (for example, IPL or flash).

Parameter Value Fluence 2 J/cmA2 Pulse Duration 2 ms Spot Area 6.4 cmA2 Pulse frequency (rep rate) 10 pulses/second 28 192784/2

Peak power 2 * 1/0.002*6.4=6,400 W

Average power 2 x 6.4 x 10 = 128 W 5 In the description and claims of the present application, each of the verbs, "comprise" "include" and "have", and conjugates thereof, are used to indicate that theobject or objects of the verb are not necessarily a complete listing of members,components, elements or parts of the subject or subjects of the verb.

All references cited herein are incorporated by reference in their entirety.10 Citation of a reference does not constitute an admission that the reference is prior art.

The articles "a" and "an" are used herein to refer to one or to more than one(i.e., to at least one) of the grammatical object of the article. By way of example, "anelement" means one element or more than one element.

The term "including" is used herein to mean, and is used interchangeably with,15 the phrase "including but not limited" to.

The term "or" is used herein to mean, and is used interchangeably with, theterm "and/or," unless context clearly indicates otherwise.

The term "such as" is used herein to mean, and is used interchangeably, with thephrase "such as but not limited to". 20 The present invention has been described using detailed descriptions of embodiments thereof that are provided by way of example and are not intended tolimit the scope of the invention. The described embodiments comprise differentfeatures, not all of which are required in all embodiments of the invention. Someembodiments of the present invention utilize only some of the features or possible 25 combinations of the features. Variations of embodiments of the present invention thatare described and embodiments of the present invention comprising differentcombinations of features noted in the described embodiments will occur to persons ofthe art. 192784/2

ABSTRACT OF THE DISCLOSURE

Methods and apparatus for damaging hair follicles using a series of rapidly-deliveredlow-fluence pulses of incoherent light are disclosed herein. In some embodiments, thepulses of coherent or incoherent light have a wavelength or wavelengths primarily inthe range between 750 nm and 1500 nm. In some embodiments, appliedelectromagnetic radiation comprising the rapidly-delivered low-fluence pulses iseffective for concomitantly heating both the sub-dermal layer (i.e. the dermis) of thetissue and the hair follicles. In some embodiments, the thermal damaging of the hairfollicles is useful for facilitating hair-removal.