초록 ▼

Intraarterial blood pressure is measured noninvasively by an electromechanical transducer. The correct hold-down force to be applied to the transducer for obtaining accurate blood pressure measurements is determined by obtaining a set of at least one of the diastolic pressure, systolic pressure, and

Intraarterial blood pressure is measured noninvasively by an electromechanical transducer. The correct hold-down force to be applied to the transducer for obtaining accurate blood pressure measurements is determined by obtaining a set of at least one of the diastolic pressure, systolic pressure, and pulse amplitude versus hold-down pressure values over a range of hold-down pressures between which the underlying artery is unflattened and it is occluded. A polynomial is fitted to at least one of the sets of values, from which polynomial the correct hold-down pressure is determined. The hold-down pressure at the point of minimum slope of graphs of the polynominals fitted to the systolic and diastolic versus hold-down pressure values provides an indication of the correct hold-down pressure. An indication of the correct hold-down pressure using the pulse amplitude measurements is provided by locating the midpoint of a pair of hold-down pressures at which the pulse amplitude is substantially sixty percent of the maximum pulse amplitude on the graph of the polynomial fitted to the pulse amplitude versus hold-down pressure values. An alternative method determines the correct hold-down pressure directly from the pulse-amplitude polynomial coefficients. A measure of the compliance of the underlying artery is obtained from the ratio of the minimum slope of the graph of the polynomial fitted to one of the systolic and diastolic versus hold-down pressure values to the slope of a straight line fitted to a subset of one of the systolic and diastolic versus hold-down pressure values over a range of hold-down pressures below which flattening of the underlying artery occurs.

대표청구항 ▼

A machine implemented method for determining correct hold-down pressure to be applied to an external pressure transducer that includes a pressure sensitive element applied to a subject at a location overlying an artery, the determined correct hold-down pressure identifying the hold-down pressure to

A machine implemented method for determining correct hold-down pressure to be applied to an external pressure transducer that includes a pressure sensitive element applied to a subject at a location overlying an artery, the determined correct hold-down pressure identifying the hold-down pressure to be employed to obtain correct blood pressure measurements using said transducer, said method comprising, (1) obtaining a continuous measurement of blood pressure with the external pressure transducer while changing the hold-down pressure on the transducer over a range from where the underlying artery is substantially unflattened to where the artery is substantially occluded, (2) obtaining from the blood pressure measurement of step 1 a set of at least one of the diastolic pressure, systolic pressure, and pulse amplitude values versus hold-down pressure over said range of hold-down pressures, (3) fitting a polynomial to at least one set of values obtained in step 2, (4) using the polynomial obtained in step 3, obtaining an indication of the correct hold-down pressure required for accurate blood pressure measurements, and (5) setting the transducer hold-down pressure at substantially the indicated correct hold-down pressure obtained in step 4 in preparation for obtaining accurate blood pressure measurements from said transducer.