Hack yourself – self knowlege through numbers
"The Quantified Self is a collaboration of users and tool makers who share an interest in self knowledge through self-tracking. We exchange information about our personal projects, the tools we use, tips we've gleaned, lessons we've learned. We blog, meet face to face, and collaborate online."
This site gives that warm feeling of finding friends in a warm café after a long chilly November walk. There are great videos from the show-and-tells on Vimeo.
Eyetracker on the cheap
"Behold the latest ocular assault weapon from the Graffiti Research Lab, openFrameworks, The Fat Lab and The Ebeling Group: The EyeWriter. It is a low-cost eye-tracking apparatus + custom software that allows graffiti writers and artists with paralysis resulting from Amyotrophic lateral sclerosis to draw using only their eyes....This instruction set details how to make your own solderless eyetracker for only $50 dollars using a hacked PS3 Eye and a cheap pair of sunglasses."
http://www.instructables.com/id/The-EyeWriter/
DIY ventilator in a pinch
In case of a shortage of ventilators, here are instructions on how to make your own.
The Reverse Geocache Puzzle
When Mikal Hart's friend got married he built a box that could only be opened in a special location. An absolutely brilliant idea and he share's how he did it!
http://arduiniana.org/projects/the-reverse-geo-cache-puzzle/
Build your own digital microscope
Digital microscopy systems can cost thousands of dollars but a very useful model can be assembled by using one decent compound microscope and consumer products that cost less than $150. Many hospitals and universities have retired micorscopes that can be adapted to this task. The plans found here show how to modify a commonly found microscope.
A DIY microscope with electronic focusing
Jean-Marie Cavanihac has put together a handly guide to turning a webcam and a lens from a discarded CD player into a focusing microscope
Principles of pulse oximetry
Pulse oximetry notes on Scribd gives a clear overview of what you need to buld your own.
Hand Dynamometer
This simple hand dynamometer is made by attaching a strain gauge to an easily available Hand Exercise Grip.
"A hand dynamometer is used to measure grip strength. The measurement of grip strength allows for comparison of left and right hand grip and muscle fatigue. Muscle fatigue can be measured by comparing the difference in hand strength measurements taken before and after an experiment has been performed. In sports, handgrip strength is important for those games where the hands are used for catching, throwing or lifting. In geriatric, one study found that poor hand strength can be used to predict disability in older people."
From Emant Pte Ltd which has several other cool projects to check out.
ECG with software noise reduction
Scott Harden has a great section on his blog about his DIY ECG and heart rate analysis. He lets the software GoldWave clean up the noise in the signal and uses nonshielded electrodes.
DIY pressure sensing
This is a useful component to build for all sorts of projects. For instance, stuck to the seat of ones pants and then recording how equal ones body weight is distributed across the back of your horse.