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Thread: Test Results - Power Density

  1. #1
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    Default Test Results - Power Density

    There seems to be a belief that as long as a 660nm red light unit is being used, that all units are more or less equal. While this is partially true in that 660nm is 660nm, the power density of the source may vary. However, it may be true that the same result may be obtained between units by adjusting the amount of exposure time (in theory at least). The problem is that if you do not quantify the amount of exposure time for each unit, then you are just guessing at the exposure time. I have stated that I believe we should quantify the power density and as well as have a "gold standard" to work from. This has not been a popular belief. The current thoughts never made much sense to me, and make even less sense now. Here are some results, you can make your own decisions.

    I compared the ebay unit talked in these threads:
    http://www.rosaceagroup.org/The_Rosa...ad.php?t=12724
    http://www.rosaceagroup.org/The_Rosa...ad.php?t=14235
    with the acnelamp tabletop all red single head.

    As a first at home comparison, you can see this thread:
    http://www.rosaceagroup.org/The_Rosa...ad.php?t=14391

    Next I tested the units with an optical power meter. I took a few shortcuts in the testing, but this should not have created a major source of inaccuracy.
    The results are mW/cm^2 followed by distance from unit

    Ebay:
    .25mW/cm^2 at a distance of 0.0"
    .16mW/cm^2 at a distance of 6.0"
    .11W/cm^2 at a distance of 12.0"

    Acnelamp:
    12.0mW/cm^2 at a distance of 0.0"
    8.9mW/cm^2 at a distance of 2.0"
    5.3mW/cm^2 at a distance of 5.0"
    2.1mW/cm^2 at a distance of 8.5"
    1.7mW/cm^2 at a distance of 12.0"

    The homemade result for the acnelamp was about 28mW/cm^2 at 0.0". I am not sure where the difference is coming from, but for now it is close enough and the relative comparison should be very close. The homemade result for the ebay unit was 0mW/cm^2. So the point is that both methods are at least achieving very ballpark agreement. The point here is that the ebay unit is putting out almost no power density, while the acnelamp is putting out significantly more. Comparing the two on a relative scale at about 5" away (should be very valid approach), the acnelamp puts out 33X (yes that is thirty three times) the amount the ebay unit puts out. Now you may ask, what is the power density you are looking for? Well, that is for debate, but I have seen research data from about 2.7mW/cm^2 to 90mW/cm^2. That is for another discussion though.

    Conclusions:
    1. The acnelamp corresponds approximately to research that says 2.7mW/cm^2 for 15min if you use it from about 6", which is the suggestion from acnelamp.
    2. If you are using the ebay unit, you will always need about 30X more exposure time than if you are using the acnelamp! Clearly, all units are not approximately the same. While it is true the ebay unit will give you the same result at the acnelamp will in 15min, it will take you about 8hrs to do so.
    3. Maybe it is not such a bad idea to listen to differing viewpoints, even if they are not popular.

    This being said, it would be great if there was an independent verification as well. I cannot guarantee the accuracy of the results, but have done it to the best of my ability with the given resources and time. Also, while I do not think the acnelamp is a particularly good deal, we at least have a way to quantify it (and the range is acceptable) so I would suggest it be the "gold standard" unit we have more data. I plan on testing some more units but in the meantime I have enough data to conduct my split face experiment. As far as I am concerned the ebay unit is an expensive flashlight.

  2. #2
    Senior Member Twickle Purple's Avatar
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    Before anyone gets discouraged (please don't, it's his opinion only), read the LLLT Introduction, where you will find actual information:

    LLLT Introduction

    From which:

    LEDís and LASERS are no more than convenient devices for producing electromagnetic radiation at specific wavelengths, and in addition to the one already cited, several other studies establish that it is the light itself at specific wavelengths that is therapeutic in nature and not the machine which produced it.

    For example, Kendric C. Smith at the Department of Radiation Oncology, Stanford University School of Medicine, concludes in an important article entitled The Photobiological Effect of Low Level Laser Radiation Therapy (Laser Therapy, Vol. 3, No. 1, Jan - Mar 1991) that:
    Radiation must be absorbed to produce a chemical or physical change, which results in a biological response. "The equation between the machine and the biological response is a common error often made Ö. Light radiation must be absorbed to produce a biological response.

    All biological systems have a unique absorption spectrum which determines what wavelengths of radiation will be absorbed to produce a given therapeutic effect. The visible red and infrared portions of the spectrum have been shown to have highly absorbent and unique therapeutic effects in living tissues.
    At the lower frequencies, however, the average output plummets into the range of microwatts (1 microwatt = 1000th of 1 milliwatt). LEDs do not deliver enough power to damage the tissue, but they do deliver enough energy to stimulate a response from the body to heal itself. With a low peak power output but high duty cycle, the LEDs provide a much gentler delivery of the same healing wavelengths of light as does the laser but at a substantially greater energy output.
    --

    I use this unit:



    And while it gave me terrific results, faster, it is a generally accepted that at the end of a year, with committed use, I would have the same results if I had used the unit from eBay. So while smaller, less powerful, units will take longer for affects to be realized the ultimate results will be no different than if you purchased a professional unit. The improvements can only go so far, the effects are cumulative (more powerful = faster, not better) and it all takes time.

    So, no need to be blinded with the science, as far as 'units' go, there are no "Gold Standards" -- I suspect this will be the sentiments of all the folks that use the Elixa/LEDMAN units with good results.

    Of course, having said this, and researched and posted for over a year about LLLT, etc., I will be told by the person's whose opinion I disagree with that I have no idea what I am talking about. C'est la vie.

    Cheers,
    TP
    Last edited by Twickle Purple; 12th March 2008 at 02:28 AM. Reason: corrected link presentation

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    "LEDís and LASERS are no more than convenient devices for producing electromagnetic radiation at specific wavelengths, and in addition to the one already cited, several other studies establish that it is the light itself at specific wavelengths that is therapeutic in nature and not the machine which produced it."

    I interpret this in a COMPLETELY different manner. All this says is that LED's and lasers have the capability to produce the same light, a 660nm source in this case. Yes, it is indeed machine independent in that respect as light is light. What is ABSOLUTELY machine dependent is the wavelength (what freq of LED, laser, etc) and power density (or power output). In my opinion, you really have read too much into this statement.

    I have not seen a single study that uses a 0.15mW/cm^2 output (lowest I have seen is 2.7mW/cm^2), that is just a ridiculously low level. You could probably get more red light from less than a minute in the sun as you could with 15 minutes with the ebay machine. Some of the original studies were based off the fact that the sun provided healing power. The goal is to eliminate the bad wavelengths and isolate to the healing wavelengths, but you still need sufficient power to have any real effect.
    Last edited by hozer2k; 12th March 2008 at 03:41 AM.

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    Tell ya what, is there even a single wound healing study that shows use at .15mW/cm^2 (or remotely close)? If not, then why would one want to use that level of output? Just does not make much sense.

    Also, you mean to tell me that if the ebay unit had even less power it would still give results if you waited longer? We are starting to get into ambient light territory or the amount of energy you would get walking to your car....I just don't see it happening and apparently none of the researchers do either. You NEED energy for this to work. If you want to penetrate the tissue to any significant depth, you HAVE to have it. You just cannot reduce it down to hardly anything and expect results.

    Also, if you noticed they said the lower peak power is compensated by a heavier duty cycle. This would go along with what most seem to agree with...that it is the total energy that matters. You get there by power density * time. So if you have lower power density you compensate with increasing time. You can't reduce the power density down so low though or the amount of time will be unrealistic.
    Last edited by hozer2k; 12th March 2008 at 03:59 AM.

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    Senior Member Steve95301's Avatar
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    Thanks for the experiments, hozer, I'm considering ordering an LLLT device with my tax return but I would want one with sufficient power output (but not too high). Obiously, I could research it myself but I'm way too busy for that

    I'd like to try combining LLLT with a vasoconstrictor to see if it could attenuate the rebound at all. I figure that constricting the vessels deprives them of oxygen, but LLLT increases oxygen efficiency so maybe it could slow down rebound and/or angiogenesis (maybe if vessels are oxygen-starved (constricted), they sprout new ones to compensate). I'd actually like to add on top of that some mitochondrial supplements like idebenone, to really crank up that electron chain and see what happens.
    KNOWLEDGE = POWER

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    http://heelspurs.com/led.html

    "Light in the red and near-infrared wavelengths immediately relieves pain and speeds healing. Journal articles have shown that light does this by "kick-starting" cells into converting energy from the krebs cycle into ATP energy for the cells. These comments are not speculative. The science behind it is mature. In the past, lasers were thought to be needed to provide the light, but now it's known that LEDs provide the same benefit. Even LEDs are not always needed because the noon-time summer Sun provides the same amount of energy (30 mW/cm^2) in the beneficial wavelengths (600 to 900 nm) as LED devices. The biggest advantage of the Sun is that it can treat the whole body at once with up to 300 Watts of 600-900 nm light rather than a small area from a 2 Watt LED device. Halogen and incandescent lights can also be used, but they have more unnecessary heat (far-infrared) than the Sun. There is a growing awareness that UV exposure from the Sun prevents many times more cancers than it causes. The research shows other wavelengths of the Sun are also beneficial. "

    So...rather than even wasting time with a low power ebay unit, you can get the same benefit in less than a minute of the sun if you don't mind exposing yourself that that level of UV exposure. Again, the whole point of this is to isolate the good wavelengths (in this case 660nm) and provide sufficient energy. If its too low, it is totally pointless and has about the same affect as stray light or minimal exposure to sunlight. Quite simply, that is how it works.

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    And again...this is totally consistent with all the research. Get the actual papers if someone does not believe me. I have obtained many of the actual papers and the papers they reference. Lack of power can be compensated by time, but they must go together. Reducing power to very low levels just will not do anything.

    http://heelspurs.com/led.html

    Healing Dosage and Application Time

    Most LED devices require 30 minutes twice a day to help tissue that is beneath the skin. Dark skin requires more time, but also absorbs more heat from the light. Several journal articles indicate 4 Joules of energy (J) applied to each 1 cm by 1 cm area (1 cm^2) per day is the best dosage for healing, but that is for injured cells that are directly exposed to the light. As much as 1000 J/cm^2 may be needed to reach injured cells 1 inch below the skin. 50 mW/cm^2 is the strength of only the best 2% of the LED units on the market and 25% more energy than the brightest sunlight in the 600 nm to 900 nm range. Before light can reach injured tissue that is beneath the skin, it must pass through skin and other tissue that greatly reduces the light intensity. It may be reduced by a factor 10 just below the skin to a factor of 50 when 1/2 inch beneath the skin. If the light is reduced by a factor of 10, then application time must be increased by the same factor of 10. This would be almost 15 minutes to get 4 J/cm^2 beneath the skin when 50 mW/cm^2 is applied at the surface (10*4/0.05=800 seconds). Our ancestors have been exposed to 5 to 30 mW/cm^2 of sunlight energy in the red and near-infrared range for up to 10 hours a day, giving an average daily dosage oin the hundreds of J/cm^2. I have found 100 J/cm^2 to reduce pains that are 1/2 inch deep from an 8 to 2. I do not think there is any harm from up to 20 minutes of 200 mW/cm^2 (360 J/cm^2), but this is 2 times more energy per cm^2 than the total energy (all wavelengths) of the brightest sun so it can definitely have heat problems. A Joule (J) is a Watt (W) applied for 1 second, so 4 J/cm^2 is the same as applying 0.05 W to each 1 cm by 1 cm area for 80 seconds (80 seconds x 0.05 W/cm^2 = 4 J/cm^2).
    Last edited by hozer2k; 12th March 2008 at 04:28 AM.

  8. #8
    Senior Member Twickle Purple's Avatar
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    Quote Originally Posted by hozer2k View Post
    And again...this is totally consistent with all the research. Get the actual papers if someone does not believe me. I have obtained many of the actual papers and the papers they reference. Lack of power can be compensated by time, but they must go together. Reducing power to very low levels just will not do anything.

    http://heelspurs.com/led.html

    Healing Dosage and Application Time

    Most LED devices require 30 minutes twice a day to help tissue that is beneath the skin. Dark skin requires more time, but also absorbs more heat from the light. Several journal articles indicate 4 Joules of energy (J) applied to each 1 cm by 1 cm area (1 cm^2) per day is the best dosage for healing, but that is for injured cells that are directly exposed to the light. As much as 1000 J/cm^2 may be needed to reach injured cells 1 inch below the skin. 50 mW/cm^2 is the strength of only the best 2% of the LED units on the market and 25% more energy than the brightest sunlight in the 600 nm to 900 nm range. Before light can reach injured tissue that is beneath the skin, it must pass through skin and other tissue that greatly reduces the light intensity. It may be reduced by a factor 10 just below the skin to a factor of 50 when 1/2 inch beneath the skin. If the light is reduced by a factor of 10, then application time must be increased by the same factor of 10. This would be almost 15 minutes to get 4 J/cm^2 beneath the skin when 50 mW/cm^2 is applied at the surface (10*4/0.05=800 seconds). Our ancestors have been exposed to 5 to 30 mW/cm^2 of sunlight energy in the red and near-infrared range for up to 10 hours a day, giving an average daily dosage oin the hundreds of J/cm^2. I have found 100 J/cm^2 to reduce pains that are 1/2 inch deep from an 8 to 2. I do not think there is any harm from up to 20 minutes of 200 mW/cm^2 (360 J/cm^2), but this is 2 times more energy per cm^2 than the total energy (all wavelengths) of the brightest sun so it can definitely have heat problems. A Joule (J) is a Watt (W) applied for 1 second, so 4 J/cm^2 is the same as applying 0.05 W to each 1 cm by 1 cm area for 80 seconds (80 seconds x 0.05 W/cm^2 = 4 J/cm^2).
    Why don't you share them then? We are here to share information, and allow others to take from that as they will. You are giving us your synopsis/opinions only, which is what Scott at heelspurs does as well. I'm not saying it's not helpful, it is. But if you have these papers you are referencing why are you not posting them for others to review as well?

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    I did not think you could post the actual papers because of copyright laws, but I am not sure really. In fact, I am presenting a paper soon and held the copyright and granted permission to the publisher for just that reason. What you can do is state the data and reference the source. Perhaps another thread can cover that, but to be honest...I am short on time now and need to take a break to cover other neglected activities. I am sure there are a lot of people here who can help collect a database though. A cumulative effort is what is needed here anyway. When I get more time, I will post the data I have and the references.

  10. #10
    Senior Member Steve95301's Avatar
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    I often face the same issue, when I'm accessing material through the University that is copyrighted.

    With this new forum software it's easy to attach a PDF, in other words it's easy to violate a copyright. I hemmed and hawed for a while before attaching a copyrighted Raynaud's book a few days ago. I still feel kinda bad.

    Although I know I'm not anonymous on this forum, my major concern was Warren getting in trouble for it because the attached files are actually hosted on Warren's server.
    Last edited by Steve95301; 12th March 2008 at 05:08 AM.
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