The therapeutic pad is the one of essential part of the Infrared Therapy Apparatus (HW-1000/HW-2000). Each pad contains 66 diodes which could give off 885nm infrared energy, and the light emitting diodes (LED) mounted in the therapy pads without any side effect. When the therapy pads are placed on the surface of skin directly, the infrared energy can penetrate 3-5cm depth absorbed by haemoglobin into body tissue, spurring endothelial cells on the inner wall of blood vessels to free nitric oxide, decreasing inducible NOs. Then the blood vessels begin to dilate and local circulation advanced, thus wound healing up, pain relief or sense of equilibrium enhanced. In other word, Nitric oxide causes dilation of nearby blood vessels and increases circulation, potentially bringing pain relief to affected areas.