Intro: LED Pain Reliever
An internet search for "near infrared light therapy" will provide you with more facts than you can take in and more fallacy than you can imagine. At this point in time one thing is sure - near infrared light (IR) therapy does relieve pain. The FDA has even approved it for such. However, other snake oil claims such as wrinkle and cellulite removal are not yet proven.
NASA is at the forefront of near IR light therapy research and has many publications dealing with the subject. (links below) One publication deals with the effectiveness of the therapy for pain management in cancer patients undergoing chemotherapy and/or radiation treatments.
Commercial LED near IR light units are available for a couple of hundred dollars to many thousands.
This unit can be built for less than $50.00 using all new off the shelf parts. I built this for my wife to use for neck and shoulder pain. She uses it every day and says it works great. I used it myself for awhile following carpel tunnel surgery and was amazed at the level of pain relief it offered. It was more effective than the pain medicine the doctor prescribed for me and the relief lasted for several hours after use.
Note that the purple color in the picture is only visible when photographing the operating unit with a digital camera. With your eyes you only see a small bit of red glow inside the LEDs.
Step 1: The Parts
These are the parts needed for this project.
- The 850 nm infared LED circuit board with LEDs and resistors
- A 12 to 15 volt wall wart
- A micro sized fan to cool the unit.
- Some sort of screen to keep your fingers out of the fan during use.
- A small switch - this is optional as you can always just plug and unplug the wall wart
- Sugru to hold it all together (Epoxy putty or silicone might also work but won't be as easy to work with as Sugru)
Sources for the main components are shown below:
LED UNIT - This kit contains 36 - 850nm 20 degree IR LEDs. $25.70
Wall Wart 12-15V 160mA. $5.10
12 vdc Micro Fan $15.49
Sugru - costs a few dollars per pack.
Step 2: The Build
First assemble the LED circuit board according to the instructions that came with it from BG Micro. Solder the wires from the wall wart to the circuit board terminals making sure you get the positive and negative wires connected to the correct terminals. Solder the wires from the fan to the same terminals on the circuit board that you attached the wall wart wires to. Again made sure you get the positive and negative wires connected properly. You can wire a switch into the circuit but it is not absolutely necessary as you can just plug and unplug it when you use it. Place the fan on the rear of the circuit board being sure it blows towards the circuit board. Place some sort of guard over the rear of the fan to keep your fingers out of the blade while you are using it. I used a piece of metal I cut off the front of an old computer speaker. You can use anything that is heavy enough not to bend and has holes in it to allow the air to enter the fan. Mix up the Sugru and mold it to hold all of the pieces together. Make sure that none of the Sugru gets near the fan blades. Set the unit aside and allow the Sugru to cure according to the manufacture's instructions.
Step 3: Use It
To use the unit simply turn it on and hold the LEDs against the area that hurts. If it is a large area, slowly move it around the area. After a few minutes you will feel a pleasant warming sensation deep within the tissue. I used this on my hand for about 10 to 15 minutes at a time with great results. My wife uses it anywhere from 10 to 40 minutes at a time. It really does help with the pain and the relief lasts several hours.
The IR from this unit penetrates the tissue for a little more than an inch. You can verify this by shining it through your hand in a darkened room and viewing the IR light coming through the other side of your hand with a digital camera.
The unit will get warm to the touch even with the cooling fan. This is normal. Like everything that uses electricity, this thing produces some heat. Be careful not to block the air flow to the fan with your fingers during use. If you do you will hear the fan speed up and the unit will start to get uncomfortably hot.
This is near infrared light, not infrared, so long exposures are not going to harm you regardless of what the folks in the want-to-be medical expert peanut gallery may say in the comments section.
Enjoy the build.