Oscillometric blood pressure monitoring device for automatic blood pressure measurements

摘要

An automated sphygmomanometer which automatically determines when a blood pressure determination needs to be made. During a "guard mode" determination, a cuff on an appendage of the patient is frequently inflated to a check pressure, which is preferably below the patient's mean arterial pressure ("MAP"), and the signature (shape, amplitude, pulse period, etc.) of the measured oscillometric signal is compared to a stored signature of a portion of an oscillometric signal at a corresponding portion of the oscillometric envelope determined during a previous blood pressure determination. If these signals differ by some predetermined amount, it is determined that the patient's blood pressure has changed significantly and that a new blood pressure determination needs to be conducted immediately. These guard mode determinations are made in addition to the normal blood pressure determinations made at predetermined intervals typically selected by the user. In addition, the shape of the oscillometric signal is quantified during guard mode so that it is possible to discriminate oscillations on the diastolic side of a patient's oscillometric envelope from oscillations on the systolic side of the patient's oscillometric envelope, thereby preventing a large shift in the oscillometric envelope from going undetected.