pulse oximeter and heart rate monitor ucing optical method

Hi,
I'm from India (kerala),in my engg. project I'm trying to build a pulse oximeter and heart rate monitor.but I didn't get any reliable schematics for it.Does any one knows from where should I get it?All replies will be encouraged...Thank you in advance....I need it urgently,Please help me.....

have a look here. **broken link removed**