This project has a certain purpose, in hospitals the doctors or assistents has to inject people with needles, now they also have to inject baby’s. The problem is these so called neonates have very chubby hands so you easily miss a vein, while injecting the needle. To overcome this problem I build a very simple and cheap device to make the veins visible and make it easy to see where you have to inject the needle.
The solution is a very simple one actually, because you can not see the vein’s with the eye you need something to “see” through the little hand. To see through the hand I used an infrared power led which is so powerfull that it shines through a human hand. The next problem is, you can not see infrared light so you need a camera with infrared vision. An infrared camera is really expensive so I decided to make one myself.
Making the infrared camera wasn’t that hard because I already did it once. I took an ordinairy webcam of 5 euro, removed the infrared blocking filter by removing a little peace of glas that is green and red colored. Then I used an little peace of picture negative, the black colored piece at the end of a strip and replaced the IR blocking filter with that. By doing that you make the IR light pass the filter, but block the normally visable light.
To make the illuminating device I used an “OSRAM – SFH4230 – IR EMITTER, 2.4W, 850NM”. This is an IR led with 2.4 watts, so a lot of light and a lot of heat! To overcome the problem of the heat I used an heat sink. Because it has to look child friendly I put the led with heat sink in a toy frog, see the picture below. The power supply is a 9 V battery and the led is placed in serie with the led. In the “Utrecht Medical Centrum” they already build a device that does a bit the same, but it definetly is not as cheap as mine.
I’m dutch so I called it the “ader-kwaker” which means in english “vein croak”. Here below are some more pictures made with the IR camera. The pictures are quite good, and you really can see the veins of the hand. For this prototype it’s a really good start. The needle also is nice visable (the needle is not in the skin itself).