Device and method for low intensity optical hair growth control

A device for reducing growth of hair on human skin, the device comprising:

• a source for emitting electromagnetic radiation in a wavelength range between 550 and 1200 nm;
• a treatment head including
• boundaries of the electromagnetic radiation, and
• a sensor configured to measure a biophysical property of the skin and a velocity with which the treatment head is moved during operation over the skin;
• and
• a controller coupled to the source and the sensor and configured to
• limit a deliverable energy density of the electromagnetic radiation on the skin to a maximum value between 5 and 9 J/cm2 in accordance with the measured biophysical property, and
• wherein during operation the maximum value is selectable by the controller in accordance with the measured biophysical property of the skin, and the maximum value of the deliverable energy density is deliverable through operation of the controller in the form of one single pulse of electromagnetic radiation having a duration between 1 and 30 ms, and
• wherein the source comprises two or more sources for emitting electromagnetic radiation and the controller is configured to maintain the energy density of a first one of the two or more sources at a constant level and adjust the energy density of the electromagnetic radiation emitted by at least a second one of the two or more sources as a function of the measured velocity.