I am currently doing some research to find out how the measured blood pressure varies between NIBP devices. Most hospitals now use patient monitors to measure non invasive blood pressure (e.g. Philips MP30, VS3, VM4 etc.). From what I've read, the device works by measuring the pressure changes and estimates the systolic, diastolic and Mean Arterial Pressure using an algorithm.

1) Does anyone know how what this algorithm is and how varies between manufacturers?

2) Is any one manufacturer more accurate than another?