Hi,

There are many projects (/products) that can be done using 8052
family of controllers. Some of them are
1. ECG monitor using a 89C52 and a graphic LCD module (been there, have done that)
2. Colorimeter
3. Stimulators
4. Non-invasive Blood Pressure apparatus using Oscillometric principle.
5. Heart rate monitors
6. Thermometers ( not the run of the mill type but more functionalities like temperature profile, etc.)

I can go on like this. Degree of complexity and requirement of supervision will vary depending on the project. For proof of concept, you can do these projects. But not for commercial application without proper testing and validation. Make sure your devices are battery operated - for safety reasons. Do projects that uses non-invasive method for signal acquition.

Have a look at the following link.

http://www.infinetivity.com/~jsampson/lcd_data/ocg1/

To extend the idea from there, you can calculate the pulse rate and display it as numerals along side the waveform.

A bit of advise, read relevant safety standards documentation even if you are not going to apply them. It will enhance your knowledge.