Lasers In Medicine
The use of lasers in medicine is now widespread. They are primarily being used for surgical procedures on eyes, blood vessels, and other body parts. Less powerful lasers are being used for noninvasive therapeutic purposes, such as stimulating healing of muscles and reducing pain and swelling in joints. Medical lasers are expensive because they generally produce great amounts of power and they must meet rigid government specifications. There are, however, some medical uses for less powerful lasers. Reports from WarnLaser customers tell about using lasers to treat osteoarthritic joint pain, muscle soreness, and other conditions. A gentleman told of irradiating a sore arthritic finger joint for about one minute with a 150 mW Pulsar. Weeks later he still had no pain in that joint. A fellow reported using a Pulsar to irradiate the sore muscles in his foot. Although the pain still remained afterwards, he reported that it was dramatically lessened. At Warn Laser we are not doctors, and our laser modules are absolutely not being marketed as medical devices. Still, such reports from our customers are intriguing, and well worth publishing.
In general, the longer the wavelength of light, the deeper it will penetrate into living tissue. The red light of a Pulsar, being of fairly great wavelength, and of similar color to blood and tissue, can penetrate deeply and possibly stimulate certain useful chemical and electrical changes. There have been reports of using green lasers for therapeutic purposes, but because of the contrasting color of blood and tissue, there is no way that green light can penetrate as deeply as red light. It must be understood that anecdotal reports from our customers does not, in any way, mean that our lasers have medical value. The positive effects which have been observed could easily be explained by the soothing heat generated by the lasers. Also, the power of positive thinking - the placebo response - could explain every report that we have received. To really know the truth of the matter, well controlled, double-blind medical studies would have to be conducted. However, that being said, the possibility of such medical values should not be dismissed.
When using lasers for therapeutic purposes, remember that used improperly, they can do great harm. A laser beam hitting flesh for even a short period of time can cause severe burns, particularly in people with black or dark colored skin. Green lasers pose a greater danger than red lasers, in this respect. If it is deemed necessary to use a laser for therapeutic purposes, it is important to keep the laser moving so that excessive heat will not be built up in any localized area of flesh; the only exception being when a laser is used for germicidal purposes. Also, because of the unknown factors in prolonged laser exposure, the same body parts should not be irradiated frequently.
Another interesting medical use for pocket lasers (of substantial power level) is that of a “pocket fluoroscope.” In emergencies, a red laser may be able to be used to inspect bone damage or look for objects embedded in the hands and feet or other thin body parts. The way this is done is to go into a dark area and press the laser against the skin on the back side of the area to be examined, such as on the palm of the hand, or on the bottom of the foot, near the toes. Lasers of substantial power may be able to provide enough illumination to produce visible shadows of broken bones, shrapnel, splinters, etc., through a centimeter or more of tissue. Like real fluoroscopy, it takes a bit of experience to know what you’re seeing. Only red lasers will work for this purpose because the light from green or blue lasers will be almost totally absorbed within the flesh being examined. Very powerful flashlights could also be used for this purpose, but may not show as much detail because of the width of the flashlight’s beam. As in most medical uses, it is important to keep the laser moving, so as to not cause burns. This is one of the few situations when it is acceptable to operate a laser without wearing laser goggles - and must be done using extreme caution. One careless move and you might be looking down the barrel of an active laser - perhaps for the last time out of that particular eye!
Although relatively impractical, in field emergencies where antiseptics are not available, a pocket laser might be able to be used to sterilize small dressings, medical instruments, and even small areas of flesh, such as shallow puncture wounds from animal bites, nails, etc. Full destruction of bacteria would be a miracle, but a 40% kill rate might be expected after irradiating an area for one minute with a 100 mW red laser. In an emergency situation, any degree of sterilization might be better than nothing - so long as no harm is done in the process. In one experiment, bacteria were more effectively killed by a red laser than an infrared one, so most probably; at any given power level, green lasers would be more effective germicidal tools than red ones. For eye health, such procedures should never be undertaken without the benefit of proper laser eyewear. The following links may be of value to those researching the medical uses of lasers: