Physiological-signal-analysis device for measuring a blood pressure and method

A method of determining whether an oscillation of a blood pressure signal satisfies a criteria, the method comprising the acts of:

• acquiring an electrocardiogram (ECG) signal having a first beat and a second beat;
• identifying a first fiducial point on the first ECG beat and a second fiducial point on the second ECG beat;
• acquiring a blood pressure signal having a first oscillation related to the first ECG beat and a second oscillation related to the second ECG beat;
• calculating a time interval between the first fiducial point and the second fiducial point;
• determining whether the time interval is an integral multiple of a nominal time interval;
• and
• rejecting the second oscillation for use in blood pressure calculations if the time interval is not an integral multiple of a nominal time interval.

A method of rejecting an artifact in a blood pressure signal, the method comprising the acts of:

• acquiring an electrocardiogram (ECG) signal having an ECG beat;
• identifying a QRS fiducial point on the ECG beat;
• acquiring a blood pressure signal having an oscillation related to the ECG beat;
• identifying a beginning-of-oscillation fiducial point on the oscillation;
• calculating a QRS-to-oscillation interval between the QRS fiducial point and the beginning-of-oscillation fiducial point;
• determining whether the oscillation is an artifact based on the QRS-to-oscillation interval;
• and
• rejecting the oscillation for use in blood pressure calculations if the oscillation is an artifact.

A physiological-signal-analysis device for determining a blood pressure value of a patient, the device comprising:

• a cuff attachable to an extremity of a patient;
• a pneumatic system connected to the cuff that supplies a fluid to the cuff;
• a pressure transducer that captures a pressure signal having a pressure oscillation;
• and
• a control unit connected to the pneumatic system and the pressure transducer, the control unit being operable to
• acquire a first oscillation having a first fiducial point,
• acquire a second oscillation having a second fiducial point,
• calculate a time interval representing a time from the first fiducial point to the second fiducial point,
• decide against selecting the second oscillation when the time interval is not a an integral multiple of a nominal oscillation period, and
• calculate the blood pressure value based upon selected oscillations.

A computer program embodied by a computer readable medium capable of being executed by a computer, the computer program capable of causing the computer to operate a physiological-signal-analysis device, the device including a cuff, a pneumatic system, a pressure transducer, and a control unit, the computer program comprising:

• a pneumatic control module for controlling the operation of the pneumatic system;
• and
• an analysis module for analyzing input from the pressure transducer and for calculating a blood pressure, the analysis module including instructions that are implemented for
• acquiring a first oscillation having a first fiducial point;
• acquiring a second oscillation having a second fiducial point;
• calculating a time interval representing a time from the first fiducial point to the second fiducial point;
• and
• determining whether the time interval is close to an integral multiple of a nominal time interval.

A method of determining whether an oscillation of a blood pressure signal satisfies a criteria, the method comprising the acts of:

• acquiring a first electrocardiogram (ECG) beat having a first fiducial point;
• acquiring a first oscillation having a relationship to the first ECG beat;
• acquiring a second ECG beat having a second fiducial point;
• acquiring a second oscillation having a relationship to the second ECG beat;
• calculating a time interval representing a time from the first fiducial point to the second fiducial point;
• determining whether the time interval is close to an integral multiple of a nominal time interval;
• and
• deciding against selecting the second pressure oscillation when the time interval is not a an integral multiple of a nominal time interval.