HAIR CARE DEVICE AND METHOD FOR ENHANCING UPTAKE OF A TOPICAL IN HAIR

Abstract

A hair care device for enhancing uptake of a topical in hair. The hair care device comprises a topical delivery unit for applying the topical to the hair surface, an ultrasound generator (103) for generating ultrasound at a frequency exceeding 15 MHz, wherein an ultrasound intensity is in a range between 2 W/cm.sup.2 and 100 W/cm.sup.2, and an ultrasound transducer (105) for applying ultrasound to the topical and/or the hair surface to enhance uptake of the topical by the hair.

Claims

1. A hair care device for enhancing uptake of a topical in hair, the hair care device comprising: a topical delivery unit for applying the topical to the hair surface; an ultrasound generator for generating ultrasound at a frequency exceeding 15 MHz, wherein an ultrasound intensity is in a range between 2 W/cm.sup.2 and 100 W/cm.sup.2; and an ultrasound transducer for applying ultrasound to the topical and/or the hair surface to enhance uptake of the topical by the hair.

2. The hair care device as claimed in claim 1, wherein the ultrasound generator is arranged to generate ultrasound at a frequency not exceeding 50 MHz.

3. The hair care device as claimed in claim 1, wherein the ultrasound generator is arranged to generate ultrasound at a frequency of at least 20 MHz.

4. The hair care device as claimed in claim 1, wherein a predetermined duty cycle of the ultrasound is in a range between 1% and 50%.

5. The hair care device as claimed in claim 3, wherein a predetermined duty cycle of the ultrasound does not exceed 12.5%, and preferably does not exceed 5%.

6. The hair care device as claimed in claim 1, wherein the hair care device comprises an array of ultrasound transducers.

7. The hair care device as claimed in claim 1, further comprising a controller for controlling a level of ultrasound intensity and a duty cycle for applying the ultrasound intensity.

8. The hair care device as claimed in claim 7, wherein the controller comprises a look-up-table for determining a level of ultrasound intensity and a duty cycle for a specific hair type or topical.

9. The hair care device as claimed in claim 7, wherein the hair care device comprises a sensor connected to the controller, the sensor being configured for sensing a parameter associated with properties of the topical and/or the hair.

10. The hair care device as claimed in claim 9, wherein one or more sensors are selected from a list comprising: a temperature sensor for sensing a temperature increase caused by the application of ultrasound, an optical sensor for sensing a change of optical properties e.g. scattering, reflectance, caused by the application of ultrasound, an acoustical sensor for sensing a change of the acoustic properties, e.g. acoustic impedance, speed of sound, caused by the application of ultrasound, and an electrical sensor for sensing a change in electrical properties, e.g. radio frequency impedance, capacitance, caused by the application of ultrasound.

11. The hair care device as claimed in claim 7, wherein the controller is configured to stop the applying of ultrasound to the topical and/or the hair before a predetermined temperature limit is reached, the predetermined temperature limit being preferably 100? C. and more preferably 50? C.

12. The hair care device as claimed in claim 1, further comprising a distance holder for positioning the transducer at a distance of more than 0.3 cm, preferably more than 1 cm, away from a skin surface.

13. A hair care method of enhancing uptake of a topical in hair, the hair care method comprising: applying the topical to the hair surface; generating ultrasound at a frequency exceeding 15 MHz, wherein an ultrasound intensity is in a range between 2 W/cm.sup.2 and 100 W/cm.sup.2; and applying ultrasound to the topical and/or the hair surface to enhance uptake of the topical by the hair.

14. The hair care method as claimed in claim 13, wherein the ultrasound is applied to the topical close to or on a hair surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 shows a first embodiment of the invention;

[0014] FIG. 2 shows a second embodiment of the invention; and

[0015] FIG. 3 shows a third embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

[0016] Embodiments of the present invention provide a handheld, preferably cordless system which generates ultrasound to treat hairs coated by a topical for enhanced uptake of said topical. The ultrasound treatment is applied through direct contact with the topical covered hairs, preferably by clamping a tress of hair.

[0017] FIG. 1 shows an ultrasound generator 103 which generates fixed or variable low-voltage ultrasound pulses, with frequency, voltage and pulse duration controlled by a controller 102 depending on treatment settings selected through a user interface 101. An acoustic amplifier 104 achieves the required output acoustic intensity. An ultrasound transducer 105 projects the ultrasound into the topical that is applied on to the hair surface 107. A practical embodiment will further feature a topical delivery unit for applying the topical to the hair.

[0018] Piezoelectric crystals (PMUT) are used to produce ultrasound (>20 kHz). Non-piezoelectric techniques like Capacitive Micro-machined Ultrasonic Transducers (CMUT) can be used for higher frequencies (typically up to 100 MHz) and can be used with this invention.

[0019] In a preferred embodiment the ultrasound transducer is embedded in the hair interface. It features a clamp to provide optimal contact with the hairs. The treatment clamps will be positioned close together in operating mode, where the distance between the clamps ideally should be smaller than one wavelength to promote uniformity, increasing the amplitude of the signal and time to result. Especially at higher frequencies this becomes an option since the energy is absorbed very quickly and might not even reach the opposed clamp. This will enable lower power usage and increase uniformity while enhancing cavitation to achieve better penetration into the hair structure. To minimize unwanted thermal effects the ultrasound could be configured in pulsed mode with 1% duty cycle and a maximum treatment time of 4 s to stay below a maximum increased temperature threshold of 100? C.

[0020] FIG. 2 illustrates such a preferred embodiment, featuring a controller 202, an ultrasound generator and amplifier 203, a topical delivery unit 206, comb teeth 209 provided with ultrasound transducers 205, and a handle 211. The topical delivery unit 206 applies the topical to a surface of the hair structure. The controller 202 controls a level of ultrasound intensity and a predetermined duty cycle for applying the level of ultrasound intensity for improved topical uptake in a hair structure. The ultrasound transducers 205 have a topical contact surface for applying ultrasound energy to the topical. Preferably, the ultrasound is applied to the topical close or on the hair surface. So the ultrasound applied to the topical will also interact with the hair. The controller may have a user interface.

[0021] One alternative embodiment features two or multiple ultrasound transducers instead of one. Having two ultrasound sources or an array of ultrasound transducers opposed to each other in both clamps of the device will decrease the time to result and probably create constructive interference. If the distance between the clamps is not predetermined the chance of destructive interference is large. This will not happen if the distance between the closed clamps is exactly multiple times the wavelength of the frequency used or (2N+1)*lambda/4 for multiple ultrasound sources.

[0022] FIG. 3 illustrates such an alternative embodiment, featuring ultrasound transducers 305A and 305B on respective clamps 313 of a hair straightener, a controller 302, an ultrasound generator and amplifier 303, a topical delivery unit 306, and a swivel mechanism 315.

[0023] Preferably, the ultrasound intensity is in a range between 2 W/cm.sup.2 and 100 W/cm.sup.2.

[0024] Preferably, the predetermined duty cycle is in a range between 1% and 50%. The inventors have found that at an ultrasound frequency of 20 MHz, a preferred upper limit of the duty cycle is 12.5%, while at an ultrasound frequency of 50 MHz, the preferred upper limit of the duty cycle is 5%.

[0025] Preferably, the hair care device comprises an array of ultrasound transducers.

[0026] Preferably, the controller comprises a look-up-table for determining the level of ultrasound intensity and the predetermined duty cycle for a specific hair type or topical.

[0027] Preferably, the hair care device comprises a sensor connected to the controller, the sensor being configured for sensing a parameter associated with the properties, e.g. temperature, moisture, of the topical and the hair. Preferably, the sensor is selected from a list comprising a temperature sensor for sensing a temperature increase caused by the application of ultrasound, an optical sensor for sensing a change of the optical properties e.g. scattering, reflectance, caused by the application of ultrasound, an acoustical sensor for sensing a change of the acoustic properties, e.g. acoustic impedance, speed of sound, caused by the application of ultrasound, and an electrical sensor for sensing a change in electrical properties, e.g. radio frequency impedance, capacitance, caused by the application of ultrasound.

[0028] Preferably, the controller is configured to stop the applying of ultrasound to the topical before a predetermined temperature limit is reached, the predetermined temperature limit being preferably 100? C. and more preferably 50? C. Alternatively, in dependence on the temperature, the intensity and/or the duty cycle of the ultrasound could be adjusted so as to prevent the temperature from becoming too high.

[0029] Preferably, in use the transducer is in physical contact with the topical and/or the hair and positioned at a distance of preferably more than 0.3 cm, more preferably more than 1 cm, away from the skin surface. This distance ensures that the ultrasound application will have its intended positive effects without unintended negative effects to hair health. To this end, the hair care device preferably is provided with a suitable distance holder to ensure this minimum distance between the transducer and the skin surface.

[0030] One alternative embodiment features systems and methods that initiate a feedback loop to measure attenuation of ultrasound in the hair structure to determine moisture content and adjust settings accordingly.

[0031] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word comprising does not exclude the presence of elements or steps other than those listed in a claim. The word a or an preceding an element does not exclude the presence of a plurality of such elements. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.