Hair-growth control device and hair-growth control method

Patent metadata

Field	Value
Publication number	US-9795443-B2
Application number	US-91415406-A
Country	US
Kind code	B2
Filing date	May 8, 2006
Priority date	May 12, 2005
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

The invention relates to a device ( 1 ) for hair-growth control of hairs ( 3 ), in particular hairs growing from human skin ( 5 ). The device ( 1 ) has a laser source ( 7 ) for generating a laser beam ( 9 ) during a pulse time, an optical system ( 15 ) for focusing the laser beam into a focal spot ( 25 ), and a laser beam manipulator ( 17 ) for positioning the focal spot in a target position. According to the invention, a dimension of the focal spot ( 25 ) and a power of the generated laser beam ( 9 ) are such that, in the focal spot ( 25 ), the laser beam has a power density which is above a characteristic threshold value for hair-growth related skin tissue above which, for the pulse time, a laser induced optical breakdown (LIOB) phenomenon occurs in the hair-growth related skin tissue. The LIOB phenomenon results in a number of mechanical effects, such as cavitation and the generation of shock waves, which damage the hair-growth related skin tissue in positions surrounding the LIOB phenomenon. An advantage of the device ( 1 ) according to the invention is that the amount of total energy which is necessary to cause trauma and induce (semi-)permanent cessation of hair-growth is at such a level that irritation and damage of the surrounding skin tissue is very limited or even completely prevented.

First claim

The invention claimed is:

1. A hair-growth control device, comprising:
a laser beam source for providing a laser beam with a pulse time,
a laser beam guiding means,
a control unit for automatically determining a target position and focus depth for the laser beam,
wherein the control unit is arranged to determine as the target position a position within a predetermined distance from hair-growth related skin tissue, which is situated between 0.3 and 5 mm below the surface of a skin to be treated when the device is in an operative position on the skin, and
an optical focusing system for focusing the laser beam to a focal spot with a power density, wherein the power density in the focal spot is above a local threshold value of the corresponding tissue for inducing a laser induced optical breakdown phenomenon in skin tissue.

2. The device of claim 1 , wherein the laser beam guiding means comprises an adjustable laser beam manipulator.

3. The device of claim 1 , wherein the laser beam guiding means comprises an optical waveguide that is suitable for insertion into a hair follicle, and arranged for guiding the laser beam to an exit opening of the waveguide.

4. The device of claim 1 , further comprising an image sensor for detecting an image of at least a portion of the skin, wherein the control unit is arranged to determine the target position from the detected image.

5. The device of claim 1 , wherein the predetermined distance is less than or equal to 50 μm.

6. The device of claim 1 , wherein the hair-growth related skin tissue comprises hair follicle tissue and/or blood vessels feeding said follicle tissue.

7. The device of claim 6 , wherein the follicle tissue comprises at least one of a matrix, a dermal papilla, a hair bulb, an outer root sheath and stem cells of the hair follicle.

8. The device of claim 4 , wherein the image sensor comprises an ultrasound imaging system or an infrared imaging system.

9. A method of hair-growth control, comprising:
generating a laser beam during a pulse time,
determining a target position and focus depth for the laser beam,
focusing said laser beam to a focal spot in skin tissue corresponding to the target position and focus depth, within a predetermined distance from a target in hair-growth related skin tissue relating to a hair of the skin,
wherein the power density in the focal spot is, for the pulse time, above a local threshold value of the corresponding tissue for inducing a laser induced optical breakdown phenomenon in skin tissue at the focal spot,
wherein the target position and focus depth are automatically determined by a control unit.

10. The method of claim 9 , wherein said predetermined distance is substantially zero.

11. The method of claim 9 , wherein the hair-growth related skin tissue comprises hair follicle tissue and/or blood vessels feeding said follicle tissue.

12. The method of claim 11 , wherein the follicle tissue comprises at least one of a matrix, a dermal papilla, a hair bulb, an outer root sheath and stem cells of the hair follicle.

13. The method of claim 9 , wherein a total pulse energy delivered to the focal spot is less than 1 mJ.

14. The method of claim 9 , wherein all the energy delivered to the hair-growth related skin tissue of each hair is delivered with a single pulse.

15. The method of claim 9 , wherein a total pulse energy delivered to the focal spot is less than 0.5 mJ.

16. The method of claim 9 , wherein a total pulse energy delivered to the focal spot is 0.2 mJ.

Assignees

• Van Hal Robbert Adrianus Maria
• Verhagen Rieko
• Roosen Guido
• Roersma Michiel Errit
• Koninklijke Philips Nv

Inventors

• Van Hal Robbert Adrianus Maria
• Verhagen Rieko
• Roosen Guido
• Roersma Michiel Errit

Classifications

• A61B18/203 Primary

  applying laser energy to the outside of the body · CPC title

• A61B2018/00904

  Automatic detection of target tissue · CPC title

• A61B2018/00476

  Hair follicles · CPC title

• A61B2018/00452

  Skin · CPC title

• A61B18/20

  using laser · CPC title