Patent ID: 6190377
Filing Date: 2001-02-20
Classification: A61B

Abstract:
A method for predicting an effective and safe laser light energy range for sub-epidermal laser surgery, comprising the steps of:impinging a measurement laser pulse on a treatment area, the pulse having an energy below a predetermined threshold of coagulation and below a predetermined threshold of skin damage;detecting a thermal emission caused by the measurement laser pulse emanating from the treatment area;measuring a delay time from the measurement laser pulse to the detection of the thermal emission;measuring a rise rate of the thermal emission;calculating a layer thickness based upon the delay time, wherein the thickness is substantially the epidermal thickness;calculating an internal measurement temperature rise based upon the layer thickness and the rise rate;multiplying the energy of the measurement laser pulse by a minimum scaling ratio to obtain a minimum laser treatment energy, wherein the minimum scaling ratio is the known coagulation temperature divided by the measurement temperature rise; andmultiplying the energy of the measurement laser pulse by a maximum scaling ratio to obtain a maximum laser treatment energy, the maximum scaling ratio is the known skin damage threshold temperature divided by the measurement temperature rise.