Development of a portable red-blue light emitting diode phototherapy system

This paper developed a portable red-blue light emitting diode phototherapy system based on the embedded technology. The device took a STM32 microprocessor as its core controller, and red and blue narrow-band LED were used as the light source, which were driven by PT4115. In order to realize the linearly adjustment of light intensity, the STM32 was used for PWM which could achieve continuously adjustable duty cycle, and the results can be displayed in screen based on STemWin. The testing results shows that the device is quite stable and reliable, which can contribute to the linearly adjustment of light intensity and satisfy the need for light intensity, distribution and uniformity.