Implantable medical devices and methods and systems for use therewith for monitoring arterial blood pressure

A system, comprising:

• memory that stores a plurality of calibrations factors each of which is associated with a respective one of a plurality of different postures, or a respective one of a plurality of different activity levels, or a respective one of a plurality of different heart rate (HR) ranges, or a respective one of a plurality of different combinations of at least two of postures, activity levels and HR ranges for a patient;
• electrodes and/or one or more sensors configured to sense a signal indicative of activity of the patient's heart, and configured to sense a signal indicative of changes in arterial blood volume of the patient;
• one or more further sensors configured to output one or more signals indicative of at least one of a current posture or a current activity level of the patient;
• and
• one or more controllers configured to determine a pulse arrival time (PAT) value by determining a time from a feature of the signal indicative of activity of the patient's heart to a feature of the signal indicative of changes in arterial blood volume of the patient;
• identify one or more of the stored calibration factors that correspond to at least one of the current posture, or the current activity level, or a current HR of the patient, or a combination of at least two of the current posture, the current activity level and the current HR of the patient;
• and
• determine one or more values indicative of the patient's arterial blood pressure based on the PAT value and the identified at least one of the one or more stored calibration factors that correspond to at least one of the current posture, or the current activity level, or the current HR of the patient, or a combination of at least two of the current posture, the current activity level and the current HR of the patient.

One or more processor readable storage devices having instructions encoded thereon which when executed cause one or more processors to perform a method, the method comprising:

• storing a plurality of calibrations factors, each of which is associated with a respective one of a plurality of different postures, or a respective one of a plurality of different activity levels, or a respective one of a plurality of different heart rate (HR) ranges, or a respective one of a plurality of different combinations of at least two of postures, activity levels and HR ranges;
• obtaining a signal indicative of activity of the patient's heart;
• obtaining a signal indicative of changes in arterial blood volume of the patient;
• determining a pulse arrival time (PAT) value by determining a time from a feature of the signal indicative of activity of the patient's heart to a feature of the signal indicative of changes in arterial blood volume of the patient;
• determining at least one of a current posture, or a current activity level, or a current HR of the patient;
• identifying one or more of the stored calibration factors that correspond to at least one of the current posture, or the current activity level, or the current HR of the patient, or a combination of at least two of the current posture, the current activity level and the current HR of the patient;
• and
• determining one or more values indicative of the patient's arterial blood pressure based on the PAT value and the one or more of the stored calibration factors identified at the identifying step.