A method of non-invasively measuring a patient's systolic and diastolic blood pressure comprising the steps of: providing a non-invasive sensor to sense a raw signal representing un-calibrated arterial pulse waveform data for a patient; providing multiple calibration equations (116, 302), to a computing device, said multiple calibration equations to be applied to input data representing a scaled and filtered arterial pulse waveform to generate output data representing a calibrated arterial pulse waveform, said multiple calibration equations being established based on arterial pulse waveforms and pressure data measured invasively or non-invasively from a sampling of the general population, wherein each calibration equation is determined for values of one or more parameters pertaining to cardiovascular features of the scaled and filtered arterial pulse waveform; non-invasively sensing, filtering and recording an un-calibrated arterial pulse waveform, wherein a signal from a sensor representing the un-calibrated arterial pulse waveform is filtered through a high pass filter and a low pass filter or through a band pass filter to provide a filtered, un-calibrated high-fidelity arterial pulse waveform in which cardiovascular features of the waveform are preserved; said method further comprising the following steps performed using said computing device: scaling the recorded, un-calibrated pulse waveform such that the amplitude of the scaled waveform is set to a fixed value; determining values of one or more parameters pertaining to cardiovascular features of the scaled and filtered arterial pulse waveform; selecting one of the multiple calibration equations based on the determined values of the one or more parameters pertaining to cardiovascular features determined from the scaled and filtered arterial pulse waveform; applying the selected calibration equation (116, 302) to the scaled and filtered arterial pulse waveform and outputting data representing a calibrated arterial pulse waveform in which a maximum value of the calibrated arterial pulse waveform correlates with the systolic pressure for the patient and a minimum value of the calibrated arterial pulse waveform correlates with the diastolic pressure for the patient; and estimating the patient's systolic peripheral blood pressure as the maximum value of the calibrated waveform and estimating the patient's peripheral diastolic blood pressure as the minimum value of the calibrated waveform. providing a non-invasive sensor to sense a raw signal representing un-calibrated arterial pulse waveform data for a patient; providing multiple calibration equations (116, 302), to a computing device, said multiple calibration equations to be applied to input data representing a scaled and filtered arterial pulse waveform to generate output data representing a calibrated arterial pulse waveform, said multiple calibration equations being established based on arterial pulse waveforms and pressure data measured invasively or non-invasively from a sampling of the general population, wherein each calibration equation is determined for values of one or more parameters pertaining to cardiovascular features of the scaled and filtered arterial pulse waveform; non-invasively sensing, filtering and recording an un-calibrated arterial pulse waveform, wherein a signal from a sensor representing the un-calibrated arterial pulse waveform is filtered through a high pass filter and a low pass filter or through a band pass filter to provide a filtered, un-calibrated high-fidelity arterial pulse waveform in which cardiovascular features of the waveform are preserved; scaling the recorded, un-calibrated pulse waveform such that the amplitude of the scaled waveform is set to a fixed value; determining values of one or more parameters pertaining to cardiovascular features of the scaled and filtered arterial pulse waveform; selecting one of the multiple calibration equations based on the determined values of the one or more parameters pertaining to cardiovascular features determined from the scaled and filtered arterial pulse waveform; applying the selected calibration equation (116, 302) to the scaled and filtered arterial pulse waveform and outputting data representing a calibrated arterial pulse waveform in which a maximum value of the calibrated arterial pulse waveform correlates with the systolic pressure for the patient and a minimum value of the calibrated arterial pulse waveform correlates with the diastolic pressure for the patient; and estimating the patient's systolic peripheral blood pressure as the maximum value of the calibrated waveform and estimating the patient's peripheral diastolic blood pressure as the minimum value of the calibrated waveform.