Ultra-pulse Laser--RF CO2 Laser Helping with Chinese Medical Esthetic Laser Equipment
As a tool that is able to achieve precision, laser is not only widely used in industrial fields, but also widely favored in medical and beauty areas. In the 1980s, laser medicine emerged as a newly rising science, gradually developed itself from a marginal discipline, and gained recognition by international organizations. Laser medical equipment has entered most medical institutions.
Laser Cosmetology-- High-precision Knife Gives You a Beautiful Life
Laser cosmetology has grown into a huge market and is still developing rapidly. Research data from Medical Insight shows that from 2011 to 2016, the global medical and beauty market was expected to achieve an average annual growth rate of 10.8%. Although North America was still the largest market, Asian market, which was expected to achieve an average annual growth rate of 13.8% in 2011-2016, was growing strongly, with Chinese market being an essential part.
Let’s delve into the market data of lasers in the medical and beauty field. In 2015, the global sales of medical and beauty lasers were 78.7 million dollars, and the figure reached 83.8 million dollars in 2016. Strategies Unlimited predicted that, with this kind of trend in market revenue, that figure would increase to 95.8 million dollars in 2017.
01 The Rapid Development of Medical Cosmetology
The rapid development of laser medical cosmetology is inseparable from the concept and operation mode of laser "selective photothermolysis" proposed by Aderson and Parrish. The concept and operation mode of laser "selective photothermolysis" are the basis of laser medical cosmetology. “Laser selective photothermolysis" requires that the laser quickly acts on the diseased area or the target area without damaging other surrounding areas. In order to minimize the impact on surrounding areas, the laser pulse width is less than the thermal relaxation time of the target tissue (the time required for the temperature of the target tissue decreases by half). The thermal relaxation time of human tissue is usually 1ms. Therefore, a laser pulse of microseconds can obtain a smaller heat-affected area.
Based on laser "selective photothermolysis", the CO2 laser, which is used in CO2 laser medical esthetic equipment, has been upgraded from a continuous laser to a pulsed laser, and then developed into an ultra-pulse laser. CO2 lasers have also developed from high-voltage direct current excited glass tube lasers into RF excited waveguide CO2 lasers. The laser beam emission method has also developed from continuous laser to millisecond pulsed laser to microsecond pulsed laser. The laser peak power has also developed from dozens of watts to hundreds of watts.
02 CO2 Laser Medical Esthetic Equipment
CO2 laser medical esthetic equipment, according to the concept and operation mode of "laser selective photothermolysis ", requires superb quality of the CO2 laser beam and narrow laser pulse width. Excellent quality of the laser beam and small focal spot of the laser equipment are conducive to the laser’s precise action on the target area. The narrower the laser pulse width, the less thermal effect the laser beam has on the tissue in surrounding areas.
In order to meet the requirements of narrow laser pulse and a short time that is shorter than thermal relaxation time of the tissue, the CO2 laser was upgraded from continuous to pulsed laser. In the 1990s, ultra-pulse CO2 lasers came into being. Ultra-pulse CO2 laser medical esthetic equipment, which is popular among doctors and patients, has splendid curative effects and causes less blood loss and pain to patients. Nevertheless, for a long time, the ultra-pulse CO2 laser has not had a definitive and quantifiable concept. In many promotional materials, CO2 lasers that can output pulses less than 1ms pulse width are called ultra-pulse lasers. This is far from rigorous. For laser pulses, in addition to the pulse width, peak power should also be considered. In the process of the interaction between laser and material, it is meaningless to talk about pulse width without taking peak power into consideration.
The laser pulse width of the ultra-pulse CO2 laser is microseconds (µs), and the peak power of the laser pulse is not less than 220W. The microsecond pulse width ensures that the time the laser takes is shorter than the thermal relaxation time of human tissue, and the high peak power ensures the energy emitted on the target area. Only pulse that meets the conditions above can penetrate 3~4mm skin tissue in an instant and act on the diseased tissue.
For RF CO2 lasers, the output pulse width is microseconds. The modulation frequency is generally 1KHz~100KHz, and the common maximum duty cycle is 100% or 60%. At 100% duty cycle, the maximum output average power is the peak power of its output pulse. For a pulse with 60% duty cycle, considering the influence of the rising and falling edges of the laser pulse, the peak power is often 2.5 times the average output power.
The relationship among RF CO2 laser pulse width (W, unit: µs), modulation frequency (Q, KHz), and duty cycle is as follows:
占空比 ：由Duty Cycle 替换
例如50KHz频率，占空比为工60%，根据上述公式，计算W=60%*1000/50=12µs
For example, frequency is 50KHz, duty cycle is 60%, according to the formula above, W=60%*1000/50=12µs
It can be seen, from the analysis above, that not all RF CO2 lasers meet the requirements of ultra-pulse. Some RF CO2 lasers meet the requirement that the laser pulse width is microseconds, but often ignore the requirement for peak power.
03 Selecting RF CO2 Lasers
When choosing a CO2 laser as the core of the ultra-pulse laser equipment, you can choose a laser with a maximum duty cycle of 60%. In this way, the maximum output power of the laser is 100W, and its peak power can reach 250W. It can then meet the requirements of ultra-pulse laser equipment for lasers.
The output of RF CO2 lasers can be 10.6µm, 9.3µm, 10.2µm, 9.6µm, and the laser beam quality factor is less than 1.5. RF CO2 lasers with output power above 100W can not only meet the requirements of ultra-pulse CO2 laser equipment, but also provide precise focal spot and offer a variety of wavelengths to choose from.
With excellent performance and reasonable price, ultra-pulse laser medical esthetic equipment that is equipped with RF CO2 laser will contribute to Chinese laser medical esthetic equipment’s better therapeutic effects offered to clients and the gaining of more competitiveness .
