Source: http://patents.com/us-7993331.html
Timestamp: 2018-06-18 06:09:29
Document Index: 307936859

Matched Legal Cases: ['Application No. 05709110', 'Application No. 200580011895', 'Application No. 177585', 'Application No. 200580011895', 'Application No. 177585', 'Application No. 200580011895', 'Application No. 2007', 'arts 34', 'art 34', 'art 34', 'arts 34', 'arts 34', 'art 22', 'art 22', 'art 26', 'art 26', 'arts 34']

US Patent # 7,993,331. Method and device for removing hair - Patents.com
United States Patent 7,993,331
Barzilay , et al. August 9, 2011
Inventors: Barzilay; Amir (Zur Hadassah, IL), Goren; Alon (Moshav Ben-Shemen, IL), Dayan; Abraham (Bat Yam, IL), Furman; Vladimir (Ashkelon, IL), Guterman; Assaf (Tel-Aviv, IL), Niv; Yehuda (Nes Ziona, IL)
Assignee: Applisonix Ltd. (Rechovot, IL)
Appl. No.: 10/590,477
PCT Filed: February 20, 2005
PCT No.: PCT/IL2005/000210
PCT Pub. No.: WO2005/079687
60546956 Feb., 2004
Current U.S. Class: 606/27 ; 601/2
Field of Search: 601/2 606/9,27
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WO 0209813 Feb., 2002 WO
WO 02/09813 Jul., 2002 WO
WO 03/065347 Jul., 2003 WO
Communication Pursuant to Article 94(3) EPC Dated Feb. 12, 2009 From the European Patent Office Re.: Application No. 05709110.0. cited by other .
Communication Relating to the Results of the Partial International Search Dated Jul. 4, 2005 From the International Searching Authority Re.: Application No. PCT/IL2005/000210. cited by other .
International Report on Patentability Dated Jul. 3, 2006 From the International Preliminary Examining Authority Re.: Application No. PCT/IL2005/000210. cited by other .
International Search Report Dated Oct. 28, 2005 From the International Searching Authority Re.: Application No. PCT/IL2005/000210. cited by other .
Translation of Office Action Dated May 23, 2008 From the Patent Office of the People's Republic of China Re.: Application No. 200580011895.8. cited by other .
Written Opinion Dated Oct. 28, 2005 From the International Searching Authority Re.: Application No. PCT/IL2005/000210. cited by other .
Written Opinion Dated Mar. 29, 2006 From the International Preliminary Examining Authority Re.: Application No. PCT/IL2005/000210. cited by other .
Office Action Dated Jul. 13, 2009 From the Israeli Patent Office Re.: Application No. 177585 and Its Translation Into English. cited by other .
Letter of Search for Prior Art Dated Oct. 27, 2004 From G. E. Ehrlich (1995) Ltd. Re.: File No. 28805. cited by other .
Response Dated Mar. 7, 2010 to Office Action of Jan. 8, 2010 From the State Intellectual Property Office of the People's Republic of China Re.: Application No. 200580011895.8. cited by other .
Response Dated Feb. 9, 2010 to Office Action of Jul. 13, 2009 From the Israel Patent Office Re.: Application No. 177585. cited by other .
Translation of Office Action Dated Jan. 8, 2010 From the State Intellectual Property Office of the People's Republic of China Re.: Application No. 200580011895.8. cited by other .
Translation of Notice of Reason for Rejection Dated Apr. 23, 2010 From the Japanese Patent Office Re.: Application No. 2007-500350. cited by other.
14. A device for treating unwanted hair protruding from a skin, the device comprising: a transducer for generating acoustic waves at a frequency of from about 150 kHz to about 1300 kHz; and a wave condenser, for gripping the hair to establish acoustic coupling between said acoustic waves and the hair in a manner such that said acoustic waves are condensed, transmitted through the hair past the skin and generate heat at a follicle, a dermal papilla, a hair bulge and/or a germinal matrix of the hair; said heat being in itself sufficient to damage or destroy said follicle, said dermal papilla, said hair bulge and/or said germinal matrix.
25. A device for treating unwanted hair protruding from a skin, the device comprising: a transducer for generating acoustic waves; and a wave condenser, for gripping the hair to establish acoustic coupling between said acoustic waves and the hair in a manner such that said acoustic waves are condensed, transmitted through the hair past the skin and increase a temperature at a follicle, a dermal papilla, a hair bulge and/or a germinal matrix of the hair by at least 20 degrees centigrade.
26. A method of treating unwanted hair, comprising transmitting acoustic waves through the hair so as to so as to generate heat at a follicle, a dermal papilla, a hair bulge and/or a germinal matrix of the hair, wherein at least one of: a frequency, a power density and duration of transmission of said acoustic waves is selected such that a characteristic amplitude of longitudinal vibrations of the hair is below 10 .mu.m.
27. A device for treating unwanted hair protruding from a skin, the device comprising: a transducer for generating acoustic waves; and a wave condenser, for gripping the hair to establish acoustic coupling between said acoustic waves and the hair in a manner such that said acoustic waves are condensed, transmitted through the hair past the skin and generate heat at a follicle, a dermal papilla, a hair bulge and/or a germinal matrix of the hair; wherein at least one of: a frequency, a power density and duration of transmission of said acoustic waves is selected such that a characteristic amplitude of longitudinal vibrations of the hair is below 10 .mu.m.
A hair is composed of a protein named keratin arranged in three layers, termed the outer cuticle; the middle cortex and the central medulla. Hair grows from a follicle, which is a small cup-shaped pit buried under the skin. The walls of the follicle form the outer root sheath of the hair. The base of the hair follicle, called the dermal papilla, is fed by the bloodstream which carries nourishment (e.g., nutrients and oxygen) to produce new hair and removes waste materials formed in the process (e.g., CO.sub.2). The lower part of the follicle widens out to form a hair bulb containing a germinal matrix, which is the source of hair growth. Hair growth is initiated in the hair bulge, which is a small swell of the hair follicle that forms the attachment site of a small smooth muscle, called the arrector pili muscle. During the anagen phase (the growing phase of the hair), the dermal papilla sends signals to the stem cells in the hair bulge to migrate, downwards along the follicle. Triggered by the dermal papilla, the stem cells begin to proliferate and, following cell differentiation, a new hair shaft is formed.
FIGS. 3a-b are schematic illustrations of a wave condenser, in a preferred embodiment in which the propagation direction of the acoustic waves, while entering the wave condenser is generally parallel to a longitudinal axis of the hair;
FIGS. 4a-b are schematic illustrations of a device for treating unwanted hair in a preferred embodiment in which the propagation direction of the acoustic waves, while entering the wave condenser is generally perpendicular to the longitudinal axis of the hair;
FIGS. 5a-d are schematic illustrations of different possible shapes for a tapered housing of a focusing element, according to various exemplary embodiments of the present invention;
FIGS. 6a-b are schematic illustrations of an acoustic waves transducer and a focusing element, according to various exemplary embodiments of the invention;
FIGS. 7a-c are schematic illustrations of a device for treating unwanted hair, which comprises a hair capturer, according to various exemplary embodiments of the invention;
FIGS. 12a-c are optical microscope images comparing hair bulbs before (FIG. 12a) and after (FIGS. 12b-c) treatment by the ultrasound waves.
According to a preferred embodiment of the present invention the generated heat results in a temperature. increment of at least 20.degree. C., more preferably at least 30.degree. C., most preferably at least 40.degree. C. Such heat in itself is sufficient to at least temporarily, preferably permanently destroy or at least damage the follicle, dermal papilla, hair bulge and/or germinal matrix. It is recognized that when the temperature of the soft tissue present in the follicle reaches high levels for a sufficient duration, a phenomenon known as "protein denaturing" can occur, resulting in a necrosis of the tissue.
Thus, according to a preferred embodiment of the present invention the coupling length h is selected such that the generated heat results in a temperature increment of 20-40.degree. C., which is preferably achieved by a coupling length of above 1 mm, more preferably above 2 mm. In various exemplary embodiments of the invention the coupling length is below 6 mm. A typical value for the coupling length is about 5 mm.
The characteristic amplitude of the longitudinal vibrations of the hair is preferably below 10 .mu.m, more preferably below 5 .mu.m most preferably below 1 .mu.m. Small longitudinal vibrations can be achieved by selecting an off-resonance frequency for the acoustic waves.
Besides depending on the coupling length, the acoustic coupling also depends on the orientation of the hair shaft, e.g., relative to the main propagation direction of the acoustic waves while entering wave condenser 24. It was found by the Inventors of the present invention that an effective transmission of energy through the hair can be achieved when the propagation direction of the acoustic waves while entering wave condenser 24 is generally parallel to the longitudinal axis of the hair shaft. This embodiment is referred to hereinunder as the "parallel orientation embodiment".
Other, non parallel orientations of the hair shaft are also contemplated. For example, in another preferred embodiment of the present invention the propagation direction of the acoustic waves while entering wave condenser 24 is generally perpendicular to the longitudinal axis of the hair shaft. This embodiment is referred to hereinunder as the "perpendicular orientation embodiment".
In an additional embodiment of the present invention, the propagation direction of the acoustic waves while entering wave condenser 24 is generally a at a predetermined angle, other than 0.degree. or 90.degree., to the longitudinal axis of the hair shaft. This embodiment is referred to hereinunder as the "inclined orientation embodiment". As will be appreciated by one of ordinary skills in the art, the inclined orientation embodiment is a linear combination between the parallel and perpendicular orientation embodiments. Representative examples of inclination angles include, without limitation, about 10.degree., 20.degree., 30.degree., 40.degree., 50.degree., 60.degree., 70.degree. and 80.degree..
FIGS. 3a-b are schematic illustrations of a particular configuration of wave condenser 24, which is preferably used in the parallel orientation embodiment. Condenser 24 preferable comprises a chamber 34 which receives hair shaft 28. Chamber 34 can be filled with an ultrasound transmission gel for the purpose of impedance matching and enhancement of acoustic coupling. The acoustic waves generated by transducer 22 (not shown in FIG. 3) are reflected from the inner side of surface 36 of chamber 34 and the energy carried by the waves is therefore entrapped in chamber 34. Hair shaft 28 is introduced into chamber 34 to form coupling length, h, (a few millimeters, as stated) between the acoustic waves and hair shaft 28. While bouncing back and forth off surface 36, the acoustic waves are transferred into hair shaft 28 from a plurality of directions, more preferably from substantially all radial directions (360.degree.). Thus, condenser 24 allows the acoustic waves to envelope a segment of the hair and not to focus on a single point of the hair. As will be appreciated by one of ordinary skill in the art, such configuration facilitates the acoustic coupling between the hair and the acoustic waves.
Surface 36 can have any shape which allows the reflection of the acoustic waves and the acoustic coupling with hair shaft 28. Preferably, surface 36 is non-planar with a characteristic radius of curvature of from about 1 mm to about 10 millimeters, more preferably between about 2 mm and about 5 mm. Representative examples of surface shapes include, without limitation, a sphere, a cylinder, an ellipsoid, a paraboloid, a hyperboloid and any combination or portion thereof. In the exemplary embodiment shown in FIGS. 3a-b surface 36 comprises a cylinder with a hemisphere head.
There is more than one configuration which is contemplated to allow wave condenser 24 to grip or capture hair shaft 28. In one embodiment, shown in FIG. 3a, hair shaft 28 is introduced through a hole 40 into chamber 34. In another embodiment, shown in FIG. 3b, chamber 34 momentarily splits, e.g., about an axis 42, into two parts (designated 34a and 34b in FIG. 3b) defining a gap 44, captures hair shaft 28 in gap 44 and reassembled on hair shaft 28. When transducer 22 is adhered to condenser 24, both transducer 22 and condenser 24 preferably split and reassembled together (see, e.g., FIGS. 4a-b and the accompanying description below). Parts 34a and 34b can be disengaged either by rotary motion thereof about axis 42 or by any other motion, e.g., a linear motion in a perpendicular, parallel or at any other direction relative to axis 42. For example, in an alternative, yet preferred embodiment, there is a complete detachment of part 34a from part 34b to enable the insertion of hair shaft 28 to gap 44. In still another preferred embodiment parts 34a and 34b slide one relative to the other to capture hair shaft 28 therebetween. Parts 34a and 34b are preferably, but not obligatorily symmetric to each other (e.g., two halves of a cylinder).
According to a preferred embodiment of the present invention, the location of hair shaft 28 within wave condenser 24 is along or close to its symmetry axis (designated 41 in FIGS. 3a-b). The advantage of this embodiment is that the positioning of the hair along the symmetry axis enhances the efficiency of energy transfer to the hair shaft, because constructive interference of acoustic waves makes the density of energy along the symmetry axis significantly larger than in other locations in chamber 34. For non-axially-symmetric shapes of chamber 34 the preferred location of hair shaft is close to the center of chamber 34.
In the embodiments in which, the hair shaft is captured by momentary splitting of condenser 24 (see FIG. 3b), focusing element 26 and/or transducer 22 preferably split together with condenser 24 (see, e.g., FIGS. 4a-b and the accompanying description below). Once a length h of hair shaft 28 enters gap 44, the splitting parts reassemble and, while hair shaft 28 is gripped inside chamber 34, transducer 22 is activated to generate the acoustic waves. Focused by focusing element 26, the waves enter condenser 24, couple with hair shaft 28 and propagate through hair shaft 28, preferably with minimal (and transverse) vibrations, toward follicle 31. Upon reaching soft tissue cells in follicle 31 (dermal papilla 32, hair bulge 35 and/or germinal matrix 33), the energy, carried by the waves in the form of local compression and tension stresses, is converted into thermal energy, leading to the increment in the temperature and creation of damage and/or the destruction of the cells.
Reference is now made to FIGS. 4a-b which are schematic illustrations of device 20 in a particular configuration which is preferably used in the perpendicular orientation embodiment. In this embodiment, transducer 22 comprises a first part 22a and a second part 22b, each having one or more active elements (respectively designated 23a and 23b), planar or non-planar, as further detailed hereinabove. Focusing element 26 also comprises a first part 26a and a second part 26b, where first 26a and second 26b parts of focusing element 26 respectively couple first 22a and second 22b parts of transducer 22 with first 34a and second 34b parts of chamber 34 of wave condenser 24. The coupling between the first parts of transducer 22, element 26 and condenser 24 is isometrically illustrated in FIG. 4b.
Once hair shaft 28 is gripped between parts 34a and 34b, transducer 22 is activated and a wave front 54 of an acoustic wave begins to propagate from active elements 23 generally parallel to a longitudinal axis 56 defined by the, shape of focusing element 26. Focusing element 26 focuses the acoustic wave onto condenser 24, such that wave front 54 continues to propagate within condenser 24, generally parallel to an axis 58 which, can be, for example, symmetry axis 41. According to the presently preferred embodiment of the invention axis 58 is substantially perpendicular to axis 56 and to hair shaft 28. If desired, the inclined orientation embodiment can be employed, in which case, axis 58 is inclined to axis 56 by a predetermined angle.
FIGS. 5a-d are schematic illustrations of different possible shapes for the tapered housing of focusing element 26, according to various exemplary embodiments of the present invention. Hence, the tapered housing can have a stepped profile (FIG. 5a) having a wider cylindrical part and a narrower cylindrical part. The height of each part is preferably about one quarter of a wavelength of the acoustic waves. In this embodiment magnification factor is given by the ratio D/d.
In another embodiment, shown in FIG. 5b, the tapered housing has a linear profile (e.g., a truncated cone).
In an additional embodiment, shown in FIG. 5c, the housing has an exponential profile. Such design offers higher magnification factors as compared to the linear profile. Its shape makes it more difficult to manufacture but its length coupled with a small diameter at the working end makes this design particularly suited to micro applications.
In another embodiment, shown in FIG. 5d, the tapered housing has a segmented linear profile, having a plurality of linear segments. For example, in this embodiment the housing can be made of a plurality of truncated cone each having a smaller opening angle. The opening angles can be selected so as to approximate an exponential profile.
FIGS. 6a-b are schematic illustrations of transducer 22 and focusing element 26 in the preferred embodiment in which focusing element 26 comprises a tapered housing. It is to be understood that although the illustrations in FIGS. 6a-b are directed at a linear profile, other profiles are not excluded from the scope of the present invention. Hence, according to the presently preferred embodiment of the invention active element 23 of transducer 22 has a spherical shape. The acoustic waves are generated by active element 23, enter focusing element 26 which focus them and generates a small volume 50 of maximal energy density within condenser 24 (not shown FIGS. 6a-b). FIG. 6b is a schematic illustration of the preferred embodiment in which transducer 22 comprises n active elements, designated in FIG. 6b by numerals 23-i (i=1, 2, . . . , n). In this embodiment, device 20 preferably comprises n focusing elements 26-i (i=1, 2, . . . , n), such that each individual active element is connected to a respective individual focusing element whereby all the focusing elements preferably focus the waves to volume 50.
Reference is now made to FIGS. 7a-c, which are schematic illustration of device 20 in accordance with additional embodiments of the present invention. Device preferably comprises a hair capturer 52 for capturing the hair. Many types of hair capturers, disposable as well as reusable are contemplated. Typical hair capturers are those being utilized in epilation devices, e.g., a brush (FIG. 7a), a net (FIG. 7b) and a clamp (FIG. 7c). Other types of hair capturers as well as combinations between two or more types are also contemplated. Additionally, condenser 24 can serve as a hair capturer, as shown in the representative example of FIG. 7c. In any event, hair capturer 52 is preferably actuated by drive mechanism 48 (not shown in FIGS. 7a-c) which imparts hair capturer 52 with a rotary and/or reciprocal linear motion as further detailed hereinabove.
In the embodiments shown in FIGS. 7a-c, transducer 22 has a shape of a cylindrical cut, where the active element is concaved hence allows the focusing of the acoustic waves into condenser 24. According to the presently preferred embodiment of the invention, condenser 24 has a shape of a portion (e.g., about one half) of a cylinder. The acoustic waves bounce back and forth between the concaved surface of transducer 22 and the symmetry axis of the cylinder, while the hair shaft is gripped by hair capturer 52 below the focal plane of transducer 22. Hair capturer 52 preferably lubricates the hair shaft with an ultrasound transmission gel during the capturing so as to enhance the acoustical contact between capturer 52 and the hair shaft. The ultrasound transmission gel can be partially or fully adhesive. Capturer 52 can incorporate grooves and/or holes through which ultrasound transmission gel or any other compound can be pushed towards the hair shaft surface. The presence of gel also enlarges the contact area and thereby improves the acoustic power transfer to the hair. Capturer 52 can also be used for pulling the hair subsequently to the destruction of the cells, as further detailed hereinabove.
Calculations performed by the Inventors of the present invention show that in order to bring the temperature of the hair bulb and hair bulge from normal body temperature to about 70.degree. C. within about 10-100 milliseconds, absorption of ultrasound power at a rate of less than 10 milliwatts is required. The ultrasound absorption in the hair bulb and hair bulge at about 1 MHz is estimated to be about 10-20% of the ultrasound energy transmitted into it, while the remaining portion of energy is transmitted into the surrounding tissue. Therefore, the required ultrasound power that needs be injected into the hair bulb and hair bulge is less than about 50-100 milliwatts.
A hair shaft of 5 mm in length (from the tip of the wave condenser 24 to the hair bulb), absorbs about 1 dB/mm at a frequency of about 1 MHz. Thus, an ultrasound power of less than about 150-300 milliwatts injected for about 10-100 milliseconds into the hair shaft can result in a temperature of about 70.degree. C. in the hair bulb and hair bulge. As stated, such temperature can destroy the cells in the follicle. A power level of 150-300 milliwatts, although small in magnitude, is rather large in density. Specifically as the hair shaft cross-sectional area is about 0.00008 cm.sup.2, a power level of 150-300 milliwatts corresponds to a power density of about 2000-4000 watts/cm.sup.2.
The wave condenser, as stated, typically grips several millimeters of hair shaft (from h.apprxeq.2 mm. to h.apprxeq.5 mm), corresponding to a total area of a few tenths of square millimeters to a few square millimeters (0.006 cm.sup.2 for h.apprxeq.2 mm and 0.016 cm.sup.2 for h.apprxeq.5 mm). By acoustically coupling between the hair shaft and the acoustic waves, the entire area the hair shaft along the coupling length, h, can be exploited for collecting the acoustic energy. A power density of 2000-4000 watts/cm.sup.2 can therefore be collected within the hair shaft using a wave condenser and an ultrasound transducer which generates from about 10 watts/cm.sup.2 to about 55 watts/cm.sup.2 of power density.
The longitudinal vibration amplitude .epsilon. of the hair shaft (the longitudinal displacement of particle along the hair shaft), can be calculated by the following equation:
.times..times..pi..times..times..times. ##EQU00001## where I is the ultrasound density, Z is the acoustic impedance of the vibrating element, and f is the ultrasound frequency.
For a density I of 4000 watts/cm.sup.2 (4.times.10.sup.7 watts/m.sup.2), a frequency f of 800 kHz, and an acoustical impedance of the hair shaft of 3.24.times.10.sup.6 kg/m.sup.2s, the vibration amplitude .epsilon. of the hair shaft near the wave condenser, according to Equation 1 above, is 0.99 .mu.m. At any other point along the hair shaft towards the hair bulb, as well as at the hair bulb and hair bulge, .epsilon. is much less than 1 .mu.m. For example, the ultrasound intensity at the distal end of the hair bulb is estimated to be about 5 times smaller than that at the hair shaft exit from the wave condenser, hence the vibration amplitude at this point is about 0.44 .mu.m. This amplitude is too small to cause a mechanical depilation of the hair.
Note that in the above discussion a rather high power density value was used. Any lower intensity value results in smaller vibration amplitude. The vibration amplitude is inversely proportional to the ultrasound frequency. Experiments made by the Inventors of the present invention showed that at an ultrasound frequency of 250 kHz, under the same operating conditions (I=4000 watt/cm.sup.2 and Z=3.24.times.10.sup.6 kg/m.sup.2s), the temperature of the hair bulb did not go beyond 40.degree. C. Borderline effects of hyperthermia or any other thermal damage are expected to occur at this low frequency level. However, even at this frequency limit value, the vibration amplitude at the distal end of the hair bulb is computed to be only 1.4 .mu.m, which is still too small to cause a mechanical depilation of the hair.
A few human hair shafts were introduced into the condenser. An ultrasound transducer was assembled directly on the condenser, without intermediate focusing element. The ultrasound transducer was operated for about 0.1 second at a frequency of 1005 kHz and a power density of about 5.2 watts/cm.sup.2 on its surface.
FIG. 9 is an infrared image of the treated hair shafts. Also shown in FIG. 9 is an image of the wave condenser. As shown in FIG. 9, the acoustic waves successfully heated the hair shafts with the hot point at the distal end of the hair shaft acquiring a temperature of 142.degree. C.
Four human hair shafts were introduced into the wave condenser of Experiment 1. For each hair shaft, a different coupling length h was defined by a different insertion depth of the hair shaft into the wave condenser. The following coupling lengths were examined, h=2 mm, h=4 mm, h=6 mm and h=8 mm. The ultrasound frequency was 817 kHz, and the power density at the surface of the ultrasound transducer was set at two values: a lower density of about 1.2 watts/cm.sup.2 and higher density of about 2.5 watts/cm.sup.2.
A human hair shaft with a hair follicle was inserted ex-vivo into rounded gel bulb, 6 mm in diameter which served as a wave condenser. The gel bulb was positioned directly on top of an ultrasound transducer, without a focusing element, with the hair bulb protruding into the air. To simulate the dermal tissue surrounding the hair bulb, a few millimeters of gel were applied on the protruding hair bulb. The ultrasound transducer was operated at a frequency 1005 kHz, providing, at its surface, about 3 watts/m.sup.2. The duration of treatment was 0.1 second.
FIG. 11 is an infrared image of the treated hair shaft. Shown in FIG. 11, is a 2 mm section of the hair shaft between the wave condenser and the gel bulb which was heated by the ultrasound waves to a temperature of about 62.degree. C.
FIG. 12c are optical microscope images comparing hair bulbs before (FIG. 12a) and after (FIGS. 12b-c) treatment by the ultrasound waves. As shown in FIGS. 12b-c the energy of the ultrasound waves, condensed by the ultrasound wave condenser and transmitted through the hair shaft, was absorbed by the hair bulb located within a thick gel bulb. The absorption of energy caused a temperature increase which was followed by a complete disfigurement of the hair bulb.
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