Abstract: A blood-pressure measurement system accurately monitors a living subject's cardiovascular state, even if the living subject's blood pressure changes during a measurement, the living subject exhibits frequent arrhythmias, or motion artifacts are present during the blood-pressure measurement. The blood-pressure measurement system of this invention provides an arrhythmia-pulse correcting circuit that corrects the amplitudes of oscillometric pulses produced by arrhythmias. An oscillometric-systolic-pressure correcting circuit corrects the measured systolic oscillometric blood pressure when a living subject's blood pressure is changing during the oscillometric blood-pressure measurement.

Abstract: A system and method for correcting a living subject's measured blood pressure when the living subject's actual blood pressure changes during an oscillometric blood pressure measurement detects oscillometric pressure pulse waves produced by a cardiac muscle of the living subject, measures a blood pressure of the living subject based on the amplitudes of the oscillometric pressure pulse waves, and corrects the measured blood pressure when the living subject's blood pressure changes during the blood pressure measurement. The system and method of this invention preferably determine an estimated blood pressure of the living subject, monitor the estimated blood pressure, and determine that the living subject's blood pressure changed during the blood pressure measurement when the estimated blood pressure changes by a predetermined amount during the blood pressure measurement.

Abstract: A system and method for identifying and correcting abnormal oscillometric pressure pulse waves detects oscillometric pressure pulse waves produced by a cardiac muscle of a living subject, identifies abnormal oscillometric pressure pulse waves and corrects the amplitudes of oscillometric pressure pulse waves produced by arrhythmias. Thus, the arrhythmic oscillometric pressure pulse waves may be retained by an oscillometric blood-pressure measurement system for use in determining a living subject's blood pressure. The system and method of this invention preferably identify abnormal oscillometric pressure pulse waves not produced by arrhythmias as artifacts. The oscillometric pressure pulse waves identified as artifacts may then be rejected by an oscillometric blood-pressure measurement system to improve the accuracy of a blood-pressure measurement.

Abstract: A method for determining the pulse rate of a person. The method of the present invention is implemented in two phases. The first phase involes the determination of pulse intervals and the second phase provides an indication of the pulse rate based on the data produced during the first phase. The first phase is implemented by an algorithm which produces a pulse distribution profile from an array of pulses obtained from an appropriate transducer. In the second phase of the measurement, the distribution is searched to locate the region of maximum density. The pulse rate within the maximally dense region are then averaged to determine pulse rate. The pulse rate detection method of the present invention eliminates a significant number of erroneous pulse signals before calculation of pulse rate, thus providing a more accurate indication of the true pulse rate.

Abstract: A method and apparatus for ensuring accurate measurement of blood pressure regardless of the position of the sensing transducer relative to the position of the patient's heart. The method and apparatus provides a hydrostatic balancing system in which a column of fluid is used to offset the hydrostatic pressure created by the corresponding column of blood contained in the blood vessel in the limb upon which the measurement is being taken. A flexible tube is routed along the patient's limb with one end being positioned at heart level and the other end terminating at the occlusion cuff which supports the pressure sensing transducer. The tube is filled with fluid and is connected to a fluid reservoir chamber located at approximately the same level as the patient's heart. The hydrostatic pressure created by the fluid in the tube effectively balances the corresponding hydrostatic pressure created by the blood in the blood vessel.

Abstract: A blood pressure monitoring system is disclosed for monitoring blood pressure during stress testing or other physical activity as well as when quiescent. The blood pressure monitoring system of the present invention includes an inflatable cuff utilized in conjunction with a controllable electric air pump and deflation valve. Audio transducers are utilized to detect pulse sound at the proximal and distal edges of the inflatable cuff and pulse sound amplitudes as well as the time delay between pulse sounds proximal to the cuff and distal to the cuff are determined. Pulse sound amplitudes are then multiplied by time delay values for selected cuff pressures to generate a greatly enhanced blood pressure evaluation curve. In a preferred mode of the present invention digital filters and statistical analysis are then employed to determine systolic and diastolic blood pressure from the evaluation curve.

Abstract: A method and apparatus for communicating with people who are both deaf and blind is disclosed. The apparatus comprises a keyboard controlled electromechanical hand. The electromechanical hand is programmed to form the letters of the standard one-hand manual alphabet through the use of an electronic buffer between the electric typewriter and the electromechanical hand. The buffer converts the electric typewriter code into separate control signals for each letter of the alphabet. Next, the buffer uses the alphabet control signals to move the hand in a manner simulating the one-hand manual alphabet code. Deaf and/or deaf and blind people feel the configurations of the electromechanical hand and are able to identify the letters. This provides an effective means of communication by persons who do not know the one-hand manual alphabet with people who are deaf and blind.