1: freckle Name： Age：21. profession：Student symptom ： It is characterized by light brown or dark brown spotted spots, round, oval or irregular. The boundary is clear, the diameter is about 2mm, the surface is smooth, isolated and not fused, and the distribution is different. diagnosis ：freckle Pathological analysis ： The patient stimulates subcutaneous pigment cells frequently during the sun exposure to ultraviolet rays, and produces a large amount of melanin pigment to stimulate tyrosinase. Dopa oxidizes to release melanin by tyrosinase; and damages the normal metabolic function of skin cells. The melanin is not discharged smoothly and remains on the skin, thereby forming spots. Freckle treatment way Indications: freckles Machine used : picoseconds Treatment: 4 weeks interval time, two sessions in total Wavelength: 1064nm Spot zie: 4-6 Energy: 80-240mj Frequency: 2-4HZ Pulse type: single pulse Clinical endpoint: whitish 2: chloasma Name：李** Age：44. profession： Waiter symptom：There are brown spots around the ankle and eyes, symmetric distribution, unclear borders, no subjective symptoms and general malaise. Diagnosis: chloasma (hip spot, liver spot, pregnancy spot) Pathological analysis ： Due to the long-term use of inferior cosmetics, the patient has thinned the stratum corneum, damaged the skin barrier, reduced sebum secretion by the sebaceous glands, decreased skin's ability to resist ultraviolet rays, and endocrine disorders, thus forming spots. Chloasma treatment way Indications：chloasma machine used：Picosecond Laser treatment course：interval time: 5weeks, total 6 sessions wavelength：1064nm spot size：7-9 Energy：80-240mj Frequency：5-7HZ Pulse mode：Double pulse Clinical endpoint：skin become little redness 3: Tattoo removal Name：宋** Age：29. profession：free profession Treatment date ：2018.5.11. symptom：tattoo on hand 6.3cm long 4.1cm width diagnosis：tattoo on hand Tattoo removal way Indications：tattoo machine used：Picosecond Laser Treatment ：Interval time 8 weeks, total 4 treatment wavelength：1064nm spot size：4-5 Energy：80-240mj Frequency：1-4HZ Pulse mode：Single pulse Clinical endpoint： Whitening （First treatment time use low frequency）