| 摘要 |
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. |
