TeleHealth Module

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.
• Good documentation needed, possibly via svg/javascript animations.
• 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
• The long, time consuming parts
  • Getting approval from governmental and medical organizations.
  • Providing an intuitive interface and a pictograph manual.
  • Drivers, integration with Measure, and construction of a usable TeleHealth Database.

3 Electrode EKG

• How to do it
  • The first part is the actual hardware part. A circuit, possibly USB powered, using op-amps, would amplify the signal received by the sensor array(of three to twelve electrodes in contact with the skin, in proximity to the heart), to a voltage usable by an ADC
  • The second part is the safety part, due to the proximity to the heart, strict regulation of leakage current is needed.
  • The third part is adapt Measure to increase functionality as a Telemedicine platform.

• Implementation
  • 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

NIR Diagnosis Aid

• 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

ADC/DAC

• 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.
• Honza Kovar(Jan), from the Czech republic, has acquired development board for the C8051F321 MCU, and will assist with programing and development.

THMDB

TeleHealth Database

Contributors

• Ian Daniher
• Honza Kovar
• Ram Dhurjaty (Simple concept suggested elsewhere)
• Rafael Ortiz
• Steve Burns

Resources

• http://www.olpcnews.com/use_cases/community/medical_application_community.html
• http://openeeg.sourceforge.net/doc/links-biopsy.html
• http://library.med.utah.edu/kw/ecg/
• http://www.uneca.org/itca/healthport/discussions.htm