This Application Note from Microchip provides a reference design for building a non-invasive blood pressure meter using the PIC24FJ128GC010 microcontroller and MCP6N11 instrumentation amplifier.
A digital blood pressure meter measures systolic and diastolic pressures by oscillometric detection. Microchip’s digital blood pressure meter demo can measure blood pressure and pulse rate during inflation. The Measurement While Inflating (MWI) principle reduces overall measuring time, which in turn reduces discomfort caused by the pressure in the cuff.
For more detail: Digital blood pressure meter design using PIC microcontroller
French 
English