Devices and Methods for Treatment of Skin Conditions

• US 20080139974A1
• Filed: 11/29/2007
• Published: 06/12/2008
• Est. Priority Date: 12/04/2006
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Da Silva, Luiz B.
• Granted Patent: US 9,492,686 B2
• Time in Patent Office: Days
• US Class Current: 601/3
• CPC Class Codes: A61B 2017/00734 battery operated
• CPC Class Codes: A61B 2018/00005 Cooling or heating of the probe or tissue immediately surrounding the probe
• CPC Class Codes: A61B 8/546 involving monitoring or regulation of device temperature
• CPC Class Codes: A61N 2007/0056 Beam shaping elements
• CPC Class Codes: A61N 7/00 Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092

Abstract

Devices and methods for the treatment of skin conditions and lesions are disclosed herein. A compact hand held device that can be safely used by those suffering from skin conditions, such as acne, warts, cold blisters, blemished skin, or fine wrinkles. The devices employ the application of ultrasound energy and heat for the treatment of skin conditions and lesions. Typically, the peak temperatures employed are about 40° C. to about 70° C. by the devices, are achieved in less than about 20 second, and maintained for less than about 40 second. Ultrasound absorption and thermal conduction transfers heat from the device to the skin and causes a biological response that accelerates acne clearing, treats blemished skin, itching, or fine wrinkles. The total heat transferred is low enough to prevent burns.

Claims

1. A handheld ultrasound device for treatment of a user'"'"'s skin, comprising:

a signal generator configured for generating a driving signal having a frequency of equal to or greater than about 10 Mz; and

an ultrasound element comprising a heat sink coupled to a piezoelectric such that a substantial temperature gradient exists across the thickness of the piezoelectric when the signal generator transmits the driving signal to the piezoelectric.

2. The device of claim 1, wherein the signal generator operates at a odd harmonic frequency of the fundamental piezoelectric frequency.

3. The device of claim 1, wherein the piezoelectric has a front surface adapted for being placed proximal to the user'"'"'s skin, and a rear surface distal from the user'"'"'s skin, and wherein the heat sink is coupled to the piezoelectric by bonding, welding or soldering a metal to the piezoelectric rear surface.

4. The device of claim 1, wherein the temperature gradient is at least about 10 degrees/millimeter.

5. The device of claim 1, wherein the heat sink has a thickness matched to a multiple of the wavelength of an ultrasound signal measured in the heat sink.

6. The device of claim 1, the ultrasound element further comprising the heat sink and a matching layer disposed between the heat sink and piezoelectric.

7. The device of claim 1, wherein the heat sink is copper.

8. The device of claim 1, wherein the device is configured for reducing the temperature of the ultrasound element to about 25 degrees Celsius before sending the driving signal to the piezoelectric.

9. The device of claim 2, wherein the driving signal is a 15 MHz driving signal and the piezoelectric has a thickness equal to about one-half the wavelength of a 5 MHz signal.

10. The device of claim 2, wherein the ultrasound element includes a matching element coupled to the piezoelectric and the matching element is configured for being placed against the skin.

11. The device of claim 10, wherein the matching element includes focusing lenses.

12. The device of claim 1, further comprising a housing holding the signal generator and ultrasound element, the housing including

a gripping portion for holding the ultrasound element in a hand of the user such that the user'"'"'s hand can place the ultrasound element in operative proximity to the user'"'"'s skin, and

a switch for causing the signal generator to generate the driving signal, the switch being configured such that the user'"'"'s hand can actuate the switch while the transducer is located in operative proximity to the user'"'"'s skin,

wherein a portion of the piezoelectric is configured for being placed in contact with the skin.

13. The device of claim 12, the driving signal has a wavelength corresponding to a frequency so that a thin piezoelectric tuned to that frequency has a first thickness, wherein the piezoelectric portion has a thickness that is at least three times higher than the first thickness.

32. The device of claim 1, the device including a tip and the ultrasound element is disposed at the tip, the device further including

a reservoir of gel or liquid;

a dispenser in fluid communication with the reservoir and configured for dispensing a gel or liquid from the reservoir.

33. The device of claim 6, wherein the heat sink is copper or brass and the matching layer is aluminum.

35. The device of claim 1, wherein the device is configured to transmit planar ultrasonic waves into the user'"'"'s skin such that the area beneath the transmitting end heats due to an uniform absorption of the about 10 Mhz ultrasonic energy.

14. A method for self-treating a skin condition using a consumer hand-held device, comprising the steps of

providing in the hand-held device an ultrasound element including a piezoelectric having an outer surface defining an ultrasound transmitting end;

placing, using the one hand, the transmitting end against the skin condition;

activating, using the one hand, the piezoelectric while the one hand holds the transmitting end against the skin condition; and

removing the transmitting end when a sensory signal is emitted from the hand-held device.

15. The method of claim 14, wherein the activating step include generating a periodic driving signal of about 10 Mhz or higher and the providing step includes providing the piezoelectric such that the thickness of the piezoelectric is about equal to [(2N+1)/2] λ

, where λ

is the wavelength associated with the periodic driving signal and N is a non-zero integer.

16. The method of claim 14, including the step of at least one of applying a topical agent to the skin before the activating step, applying a topical agent to the transmitting end before the activating step, and applying a topical agent after the removing step.

17. The method of claim 14, wherein the topical agent is an acne gel.

18. The method of claim 14, wherein the sensory signal is one of an audio or visual signal emitted from the device.

19. A method for therapeutic treatment of the skin using an ultrasound device having a transmitting end, comprising the steps of

placing the transmitting end on a skin condition;

and

treating the skin condition including the step of heating the skin with ultrasonic energy of equal to or greater than about 5 Mhz using planar ultrasonic waves emitted from the transmitting end, and such that the skin surface temperature is less than a temperature of skin adjacent to the skin surface.

20. The method of claim 19, wherein the heating the skin step includes generating heat from the piezoelectric coupled to a heat sink, such that the temperature profile through the skin has a maximum value at about 2 mm beneath the skin surface and decreases in magnitude nearer to the skin surface.

21. The method of claim 19, further including the step of maintaining a maximum temperature beneath the skin for about 20 seconds.

22. The method of claim 19, wherein the treating step includes the step of delivering heat energy in an amount less than about 50 J/cm².

23. The method of claim 22, wherein the treating step includes the step of delivering heat energy in an amount less than about 50 J/cm² and for a period of about 20 seconds.

24. The method of claim 19, wherein the treating step includes the step of delivering heat energy in an amount less than about 5 J/cm².

25. The method of claim 19, wherein the treating the skin condition step includes heating the skin between about a temperature of 40 degrees and 85 degrees Celsius.

26. The method of claim 19, wherein the treating the skin condition includes the step of maintaining a peak temperature for about 1 second to 60 seconds.

27. The method of claim 19, wherein the treating the skin condition is treating one of an acne vulgaris, viral skin lesion, skin irritant, and fungal infection condition using ultrasonic energy.

28. The method of claim 19, wherein the treating the skin condition is treating a hair follicle and hair root such that the absorbed ultrasonic energy damages the hair follicle and root to reduce hair growth.

29. The method of claim 19, wherein the treating the skin condition is treating wrinkled skin, further including the steps of providing a matching layer including focusing lenses placed in contact with the skin, and damaging isolated regions of the skin while leaving undamaged skin between the isolated regions.

30. The method of claim 19, wherein prior to the heating the skin step applying a substance to the skin.

31. The method of claim 30, wherein the applying a substance to the skin step includes the step of dispensing a topical agent from the device.

34. The method of claim 19, wherein the placing the transmitting end on a skin condition corresponds to the placing of a front surface of a piezoelectric element against a skin surface.