The 10usd TeleHealth Module

This low cost, multifunction peripheral will provide a means through which the XO can relay valuable medical diagnostic data from the field to doctors many kilometers away.
It will compose of a three lead EKG providing valuable information about the heart's electrical status, enabling diagnosis of congenital defects and various arrhythmias.
It will also contain a multipurpose NIR diagnosis tool whose primary function is that of a pulse oximeter, providing information about the oxygen saturation of the blood.
- See nirdiagnositics.com for other NIR functions

3 Electrode EKG

Multiple Op-Amps pick up, amplify, and filter electrical impulses picked up by near-heart electrodes.
- Older EKGs used suction based reusable electrodes, an adaption of these may be best suited for the third world where replacements are scarce.
DyD/DyDisMe has schematics for an EKG using AD620A style op-amps.
- 4.1044-7.3 usd
Ram Dhurjaty, a medical device professional who has had substantial experience with EKG amplifiers, has pointed suggested that there are better amplifiers than the AD620.
Dirakx(Rafael Ortiz) is currently in the prototyping phase of an EKG, to incorporate into the THM, as of Nov. 14th of 2007

Based on the principles of the differences in absorption of oxygenated and non oxygenated hemoglobin
800-1000nm light from LEDs are often used in NIR tools
- The most cited frequencies for IR Pulse Oximetery include 805nm, 910nm, and 940nm.
- 940nm IR LED; 12.2c per unit
Red light is generated from similar LEDs.
- 10-20c per unit
Light is picked up by photodiodes, converted to current.
This current is amplified and converted to voltage by a MAX4006 or equivalent chip
- 1.275 usd

C8051F321 or equivalent chip
- A/D 5x10b minimum
- This specific chip provides A/D 13x10b
alternatively a USB micro-controller may communicate with dedicated ADC/DAC chips via PWM, to lower cost.

Some talk of a pictograph/text based diagnosis library/activity has been made.
User:DyD has collected some diagnosis aids used by a local hospital.
User:ZdenekBroz has been working on a wikislice of relevant medical information.
A very simple pygtk/xml based activity could be made using if/elseif clauses to mimic a diagnostic flowchart.
The biggest problem here is legal liability, a hefty disclaimer may be needed.