Optical Heartbeat Detector

http://www.johnhenryshammer.com/TEChREF/opAmps/opamps.html http://www.8051projects.net/_heartbeat_sensor_using_infrared_LED http://www.htw-aalen.de/extern/dti/Ti_proj/puls_3/puls_3.htm (translated) http://www.htw-aalen.de/extern/dti/Ti_proj/puls_1/puls_1.htm (translated) http://www.htw-aalen.de/extern/dti/Ti_proj/puls_2/Start.htm (translated)

DIY Electrocardiograph

http://www.eng.utah.edu/~jnguyen/ecg/ecg_index.html http://www.diyhappy.com/homemade-ekg/ I was thinking about hooking one up to the ADC on a PIC microcontroller and use a high capacity SD card to log heart beat throughout the day as a fun experiment. Update - more links: http://www.cisl.columbia.edu/kinget_group/student_projects/ECG%20Report/E6001%20ECG%20final%20report.htm http://forum.allaboutcircuits.com/showthread.php?t=6356 http://www.esnips.com/doc/07625f96-c19d-421b-bf0a-1c12efec2abb/ECG-circuit-guide http://www1.hut.edu.vn/vlir/STATIC/list/PhamYen7.pdf And more: http://engnet.anu.edu.au/DEpeople/Salman.Durrani/_teaching/TA1.pdf http://blog.ednchina.com/Upload/Blog/2007/8/23/ef1b052e-b8dd-466f-a7bc-b9ab542a11d8.pdf