DIY Sub $5 EKG

Jason Nguyen over at the University of Utah Engineering School has put together instructions on how to build your own EKG machine for $4.23 using your computer and a couple of components. Jason does present a nice question: If its possible to build an EKG for under $5 and any computer… why do medical devices cost so much?

Jason has some pretty extensive instructions on the build and after a nice disclaimer:

Please be aware that you are doing this at your own risk. I am not responsible for any stopped hearts, practical jokes, code gone awry, or any close encounters with a supreme being. Please understand the risks of electricity before attempting anything on this site

he gets right into it with a materials list:

Although you can use any distributor you like, I suggest Mouser. They’re cheap, they have tons of stuff, and they don’t have a minimum order. If you came here before (or read the slashdot post), you’ll notice that the cost has gone up. That’s because I put in some extra protection items.

$2.01 = 3 x LF353 - Dual Op-amp ($0.67 x 3) (you may be able to reduce cost by purchasing two quad LF347 @ $0.67 each) - Mouser

$0.55 = 5′ x 2-conductor shielded wire ($0.11 x 5) - Home Depot

$0.36 = 12 x 100k Ohm resistor 1/4 Watt 1% tolerance (0.03 x 12) - I personally used 5% carbon film resistors, but it appears as though metal film ones are now cheaper and better. Maybe someone can tell me why. Mouser

$0.24 = 8 x 10k Ohm resistor 1/4 Watt 1% tolerance (0.03 x - two extra in case 100k is too much resistance in the input stage - Mouser

$0.35 = 1 x 1uF Ceramic capacitor - Mouser

$0.08 = 1 x .1uF Ceramic capacitor - Mouser

$0.18 = 6 x silicon diodes - 1N4001 (.03 x 6) - Mouser

$0.43 = 1 x 1/8″ (3.5mm) phone plug to connect to the sound card - Mouser

$0.03 = 3 x Pennies for electrodes

——

$4.23 - Total cost (Used to be $3.93)The rest of the stuff I don’t consider to be part of the cost of the project - mostly because they’re reusable and depend on how you plan on building it

Proto-Type Board

Soldering Iron

Wire (to computer and to connect parts together)

9V battery

Lotion

Tape