Abstract: Embodiments of the invention provide a method and system for measuring first phase ejection fraction where simultaneous measurement of the systolic pressure during systole of a subject is undertaken at the same time as measurement of the left ventricle volume (LVV). The pressure waveform is then analyzed, for example using automated signal processing techniques, to find a time T1 which corresponds to the point at which the rate of change of systolic pressure during systole begins to reduce. The left ventricle volume at this time T1 is then found from the previous measurements of LVV obtained at the same time as the systolic pressure measurement, and the first phase ejection fraction then calculated in dependence on the LVV at time T1 and the LVV at the start of systole i.e. the end diastolic volume (EDV). In particular embodiments, the first phase ejection fraction is the difference between LVV at EDV and LVV at time T1.

Abstract: The application relates to an apparatus and a method for estimating a central systolic blood pressure (cSBP) of a subject, in which a peripheral blood pressure waveform of the subject's pulse and at least two peripheral blood pressure measurements within the cardiac cycle of the subject are determined and the peripheral blood pressure waveform is manipulated with a transfer function to provide an estimate of the central blood pressure waveform of the subject's pulse. The at least two peripheral blood pressure measurements within the cardiac cycle of the subject and the peripheral blood pressure waveform of the subject's pulse are determined at substantially the same point on a peripheral artery of the subject. The estimate of the central blood pressure waveform of the subject's pulse provides an estimate of the central systolic blood pressure of the subject.

Abstract: Embodiments of the invention provide a method and system for measuring first phase ejection fraction where simultaneous measurement of the systolic pressure during systole of a subject is undertaken at the same time as measurement of the left ventricle volume (LVV). The pressure waveform is then analyzed, for example using automated signal processing techniques, to find a time T1 which corresponds to the point at which the rate of change of systolic pressure during systole begins to reduce. The left ventricle volume at this time T1 is then found from the previous measurements of LVV obtained at the same time as the systolic pressure measurement, and the first phase ejection fraction then calculated in dependence on the LVV at time T1 and the LVV at the start of systole i.e. the end diastolic volume (EDV). In particular embodiments, the first phase ejection fraction is the difference between LVV at EDV and LVV at time T1.

Abstract: Embodiments of the present invention provide an improved transformation method whereby the peripheral pulse waveform is filtered to separate different phases which make up the waveform. The separate phases are transformed before being re-combined to provide an estimated intra-arterial transfer function. For example, in one embodiment the peripheral pulse waveform is filtered by a first high pass filter, and a copy of the peripheral pulse waveform filtered by a second high pass filter, having a different cut-off frequency. The two filtered waveforms may then be further processed, for example by being added back to original wave-form, and are then multiplexed together in a time division manner to provide a final waveform.

Abstract: The application relates to an apparatus and a method for estimating a central systolic blood pressure (cSBP) of a subject, in which a peripheral blood pressure waveform of the subject's pulse and at least two peripheral blood pressure measurements within the cardiac cycle of the subject are determined and the peripheral blood pressure waveform is manipulated with a transfer function to provide an estimate of the central blood pressure waveform of the subject's pulse. The at least two peripheral blood pressure measurements within the cardiac cycle of the subject and the peripheral blood pressure waveform of the subject's pulse are determined at substantially the same point on a peripheral artery of the subject. The estimate of the central blood pressure waveform of the subject's pulse provides an estimate of the central systolic blood pressure of the subject.

Abstract: The application relates to an apparatus and a method for estimating a central systolic blood pressure (cSBP) of a subject, in which a peripheral blood pressure waveform of the subject's pulse and at least two peripheral blood pressure measurements within the cardiac cycle of the subject are determined and the peripheral blood pressure waveform is manipulated with a transfer function to provide an estimate of the central blood pressure waveform of the subject's pulse. The at least two peripheral blood pressure measurements within the cardiac cycle of the subject and the peripheral blood pressure waveform of the subject's pulse are determined at substantially the same point on a peripheral artery of the subject. The estimate of the central blood pressure waveform of the subject's pulse provides an estimate of the central systolic blood pressure of the subject.

Abstract: Embodiments of the present invention provide an improved transformation method whereby the peripheral pulse waveform is filtered to separate different phases which make up the waveform. The separate phases are transformed before being re-combined to provide an estimated intra-arterial transfer function. For example, in one embodiment the peripheral pulse waveform is filtered by a first high pass filter, and a copy of the peripheral pulse waveform filtered by a second high pass filter, having a different cut-off frequency. The two filtered waveforms may then be further processed, for example by being added back to original wave-form, and are then multiplexed together in a time division manner to provide a final waveform.

Abstract: The application relates to an apparatus and a method for estimating a central systolic blood pressure (cSBP) of a subject, in which a peripheral blood pressure waveform of the subject's pulse and at least two peripheral blood pressure measurements within the cardiac cycle of the subject are determined and the peripheral blood pressure waveform is manipulated with a transfer function to provide an estimate of the central blood pressure waveform of the subject's pulse. The at least two peripheral blood pressure measurements within the cardiac cycle of the subject and the peripheral blood pressure waveform of the subject's pulse are determined at substantially the same point on a peripheral artery of the subject. The estimate of the central blood pressure waveform of the subject's pulse provides an estimate of the central systolic blood pressure of the subject.

Abstract: A method of obtaining an estimation of a person's aortic systolic blood pressure, which method comprises non-invasively measuring the person's brachial systolic blood pressure, non-invasively measuring the person's brachial diastolic blood pressure, obtaining the person's radial augmentation index by measuring the person's radial pulse waveform, and obtaining the estimation of the person's aortic systolic blood pressure from the following equation: aSBP=?+?·rA1x+?·bSBP+?·bDBP where the coefficients ?, ?, ? and ? are constants with approximate values of ?=?24.2, ?=0.28, ?=0.83, ?=0.17.

Abstract: A method of measuring endothelial function in a person (2), which method comprises applying pressure to one arm of the person (2) such as to restrict blood flow in the arm (6), releasing the pressure in order to cause an increase in blood flow in the arm (6) due to reactive hyperaemia, and then measuring the difference in pulse propagation time between the two arms (6, 8) of the person.

Abstract: A method of measuring endothelial function in a person (2), which method comprises applying pressure to one arm of the person (2) such as to restrict blood flow in the arm (6), releasing the pressure in order to cause an increase in blood flow in the arm (6) due to reactive hyperaemia, and then measuring the difference in pulse propagation time between the two arms (6, 8) of the person.