Highest power, NON-burning, no duty cycle?

[LaserDr]

I'm a doctor, and I've been using a Class IV laser very successfully in my practice for several months. I want to do some tests with a portable red laser, probably 650nm. It has to be non-burning, non-stinging to the skin. What's the highest power I could safely use? Would an adjustable focus laser with the focus opened up all the way make a 100 mw laser non-burning? It would also be great if it had a continuous on button with no duty cycle. What's the highest power non-burning laser with no duty cycle?

Thanks for your help.

 

[bobhaha]

This seems so dodgey... What do you need the laser for? What will it be used for/on?

 

[LaserDr]

Lasers have been used medically since 1967. If you search at pubmed.gov, the medical database of the National Institutes of Health, you will find thousands of research studies. Lasers are used to reduce pain and inflammation, but they also stimulate healing at the mitochondrial level -- at the level of the cell. They have been used successfully to heal many conditions -- arthritis, disc herniations, tendon repair, etc. A recent paper from Harvard Medical School focused on Laser Therapy and Neurorehabilitation -- using lasers to help heal strokes, Alzheimer's, Parkinson's, and Traumatic Brain Injury. Some of this is preliminary, but it's very exciting.

The laser I use in my practice is the Cutting Edge MLS laser -- the website is med.celasers.com

 

[Cyparagon]

Where we are expected to believe a stupidly-over-priced pointer can cure virtually every pain ailment in existence.

To OP: it's LOW LEVEL laser therapy, right? Why are you looking for a high power laser for low level laser therapy? Just use IR LEDs instead... unless you think adding the word "laser" to a device accounts for most of the clinical success.

</cynicism>

 

[LaserDr]

1. Okay... I find it very strange that when I post a question on a laser forum about lasers I get personally attacked. I am not attempting or wishing to convince anyone about anything. I am asking, basically, two questions: First, what is the maximum powered red laser I can use that will not sting the skin if the beam is unfocused? Second, where can I find a laser with this power with an unlimited duty cycle and a continuous on button?

2. If you don't wish to help me with this, that's your choice. But I would respectfully ask that you stay on topic and stay away from personal attacks.

3. However, to answer your concerns – if you are somehow offended or have your cynicism set off by the fact that I am a doctor using lasers in my practice, then I would respectfully suggest that you may want to do some research. That, of course, is your choice. Cynicism can be healthy, but is certainly not healthy if it is based on lack of knowledge of facts.

4. I researched for years before I bought the laser I am using. I looked at hundreds of studies, talked to many other doctors, had demos of lasers on myself, and tried other doctor's lasers. I finally made my decision after I had a demo of the Cutting Edge laser on four very difficult patients – with herniated disc, peripheral neuropathy, plantar fascitis, and torn spinal ligaments. Three of the four had a decrease in pain from 7-8/10 to 0-2/10 in one 15 to 30 minute treatment. The results have been consistent since then with over 90% of my patients. Harvard Medical School – probably the most respected and prestigious medical school in the world – now has a Department of Photobiology devoted to studying and teaching forms of laser and light therapy. There is no question that therapeutic lasers are extremely valuable in medicine. If you are curious, you can look at the Cutting Edge Laser website and you will see a video where orthopedic surgeons, pain management M.D.s, podiatrists, chiropractors, and veterinarians are all describing the therapeutic effectiveness of this laser.

5. “Low level laser therapy” is only one form of laser therapy, using a Class III laser. (The laser I use in my practice is a Class IV.) For these tests, I want to use a laser rather than an LED because the laser has better skin penetration.

6. Again, I do not have the time or the desire to get into a discussion of whether or not laser therapy works. I would ask that you please keep replies on topic, as answers to my questions. Thank you.

 

[Wolfman29]

Just one point to make - why do you think a laser has better skin penetration? There is nothing remarkably special about the light emitted by a laser that would affect the human body any differently than an LED would. Lasers and LEDs only differ in a few aspects:
- Coherence: Lasers emit coherent light which means that the electrical and magnetic aspects of the EM propagation of all of the various photons being emitted line up in sync.
- Small emitter size: This allows lasers to be focused to a small point and stay small over long distances.

There are other technical aspects, but for most purposes, those are the only important differences. That said, you want to use a defocused laser which would act essentially like an LED with a longer coherence length. As far as I am aware, the human body would not react any differently to light with short coherence lengths vs. long coherence lengths.

As long as you can match the wavelength of the laser to that of an LED, they will be functionally the same. I can imagine a scenario where you may very well need a short bandwidth light source, so in that case, an LED would not suffice, but for that, you wouldn't want a laser diode, either.

In conclusion... it is the wavelength of the light that affects skin penetration, not whether or not it has laser in the name. I would suggest you use an LED.

 

[Fiddy]

Lasers have been used medically since 1967. If you search at pubmed.gov, the medical database of the National Institutes of Health, you will find thousands of research studies. Lasers are used to reduce pain and inflammation, but they also stimulate healing at the midichlorian level-- at the level of the cell. They have been used successfully to heal many conditions -- arthritis, disc herniations, tendon repair, etc. A recent paper from Harvard Medical School focused on Laser Therapy and Neurorehabilitation -- using lasers to help heal strokes, Alzheimer's, Parkinson's, and Traumatic Brain Injury. Some of this is preliminary, but it's very exciting.

The laser I use in my practice is the Cutting Edge MLS laser -- the website is med.celasers.com

 

[Cyparagon]

I researched for years before I bought the laser I am using. I looked at hundreds of studies, talked to many other doctors, had demos of lasers on myself, and tried other doctor's lasers...

And through all of this research and first hand experience... where did you come up with the highly technical "won't burn skin" as a suggestion for laser power?

 

[InfinitusEquitas]

:crackup:

op:

 

[Soren]

 

[LaserDr]

Just one point to make - why do you think a laser has better skin penetration? There is nothing remarkably special about the light emitted by a laser that would affect the human body any differently than an LED would. Lasers and LEDs only differ in a few aspects:
- Coherence: Lasers emit coherent light which means that the electrical and magnetic aspects of the EM propagation of all of the various photons being emitted line up in sync.
- Small emitter size: This allows lasers to be focused to a small point and stay small over long distances.

There are other technical aspects, but for most purposes, those are the only important differences. That said, you want to use a defocused laser which would act essentially like an LED with a longer coherence length. As far as I am aware, the human body would not react any differently to light with short coherence lengths vs. long coherence lengths.

As long as you can match the wavelength of the laser to that of an LED, they will be functionally the same. I can imagine a scenario where you may very well need a short bandwidth light source, so in that case, an LED would not suffice, but for that, you wouldn't want a laser diode, either.

In conclusion... it is the wavelength of the light that affects skin penetration, not whether or not it has laser in the name. I would suggest you use an LED.

Wolfman29, thank you for your help.

I looked into this question. There is quite a bit of conflicting opinion on the internet about this, but here is an article summarizing the theory and research on LEDs vs. lasers:
Lasers vs. LEDs: Would you take a knife to a gunfight? – Healing Light Seminars

What the article boils down to is that when studies compare LEDs to lasers, LEDs are effective in therapy but not as effective as lasers.

I am still learning as much as I can about lasers. How does a defocused laser act like "an LED with a longer coherence length." Does the coherence of a laser change when it is defocused? What is the significance of a longer vs. a shorter coherence length?

 

[kilter]

You could have a 5 watt laser with out focusing and it would no burn... lol

 

[nouthyella]

Lasers vs. LEDs: Would you take a knife to a gunfight? – Healing Light Seminars

I guess this won't be of much help, since OP has likely left this forum for good, but whoever wrote that article clearly has not seen this.
http://laserpointerforums.com/f39/p...ed-w-heatsink-optics-14-shipped-us-74920.html

There is absolutely no reason why a LED emits less light than a laser diode. That LED utterly overpowers any commonly sold laser diode in existence.

Regarding the papers sourced, the writer may appear to be simply trying to go for quantity over quality, and may have included many poorly done experimental papers in his list. I suggest that you actually read the papers to see if their protocols truly did follow proper, double-blind experimental procedure.

 

[Laser Smith]

You could have a 5 watt laser with out focusing and it would no burn... lol

I can remove the focusing module from any of my 1w+ 445's and it will still ignite some materials when they're within about 6 inches