A method of measuring a patient's systolic and diastolic brachial blood pressure non-invasively with a brachial cuff considers the shape of a patient's peripheral waveform (e.g., the cuff volumetric displacement waveform) to recalibrate the height of the waveform. The maximum and minimum values of the recalibrated waveform correlate to and closely estimate counterpart values for invasively measured brachial systolic and diastolic pressure.