Spacelabs, Inc.

Richard A Walloch

Jack M Millay

A system for determining if a blood pressure measurement made by an automatic blood pressure monitor has been adversely affected by artifact. The system first compares the diastolic, mean arterial and systolic pressures to respective average diastolic, mean arterial and systolic pressures. If all three of these pressures are within a predetermined range of their corresponding average pressures and if the relationship between these pressures conforms to a physiologically realistic model, then the diastolic, mean arterial and systolic pressures obtained from a measurement are considered valid. If more than one of these pressures is outside the predetermined range of its corresponding average pressure, then the measurement is considered to be adversely affected by artifact and is rejected. If only one of these pressures is outside the predetermined range of its corresponding average pressure, then a replacement pressure is calculated for that pressure. The replacement pressure is calculated based on the pressures that are within the predetermined range and on an average of pressures from previous measurements.

Method and apparatus for distinguishing between accurate and inaccurate

A system for identifying artifact in automatic blood pressure measuring system. The system determines whether a single blood pressure signal, such as an oscillometric pulse or Korotkoff sound, occurs for each QRS complex of an ECG waveform in order to verify that the blood pressure signal is valid. In the event that multiple blood pressure signals occur between successive QRS complexes, at least some of the blood pressure signals are determined to be induced by artifact.

Apparatus for identifying artifact in automatic blood pressure

A method and apparatus for determining the mean arterial pressure in an automatic blood pressure measuring system in which a table of data is obtained of cuff pressures and the amplitude of oscillometric pulses produced at each cuff pressure. The oscillometric pulses having the greatest amplitude and a reference cuff pressure at which such oscillometric pulses occurred are first identified from the table. Respective first and second cuff pressures that are above and below the reference cuff pressure and have a amplitude of 90% of the largest oscillometric pulses are then calculated by interpolating between the measured data in the table, and the mean arterial pressure is then calculated as the average of the first and second cuff pressures.

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Beaverton, OR, United States of America

Richard A Walloch