Cardiac Function Assessment System

A method for determining a basal cardiac fitness of a user in an unstressed state, comprising:

• (a) providing a noninvasive sensor system configured to detect changes in blood volume or blood flow in a measurement region of the user, where the changes are indicative of opening and closing of the user's aortic valve;
• (b) acquiring a measurement signal from the noninvasive sensor system;
• (c) determining from the measurement signal an ejection time from an aortic valve opening until a successive aortic valve closing, and two or more interbeat intervals, where the interbeat interval is the time from an aortic valve opening until a successive aortic valve opening;
• (d) determining the presence of preload independence and the presence of cardiac vagal control based on the interbeat intervals;
• (e) if preload independence and cardiac vagal control are present, then determining a cardiac fitness score based on the ejection time;
• (f) reporting the cardiac fitness score.

A method for determining a basal cardiac fitness of a user, comprising:

• (a) providing a noninvasive sensor configured to detect changes in blood volume or flow in a measurement region of the user;
• (b) providing a sensor control system configured to operate the noninvasive sensor at operational parameters to acquire a measurement signal;
• (c) providing a physiological assessment system configured to determine the presence of a basal physiological state from a measurement signal;
• (d) providing a trigger system configured to trigger the sensor control system to alter operational parameters if a basal physiological state is determined;
• (e) providing a cardiac fitness assessment system configured to determine a cardiac fitness score from a measurement signal;
• (f) using the sensor control system sensor to operate the noninvasive sensor at a first set of operational parameters to produce a first measurement signal;
• (g) using the physiological assessment system to determine the presence of a basal physiological state from the first measurement signal;
• (h) if a basal physiological state is determined, using the trigger system to trigger the sensor control system to alter operational parameters;
• (i) using the sensor control system sensor to operate the noninvasive sensor at a second set of operational parameters to produce a second measurement signal;
• (j) using the cardiac fitness assessment system configured to determine a cardiac fitness score from the second measurement signal;
• (k) reporting the cardiac fitness score.

A method for determining a basal cardiac fitness of a user, comprising:

• (a) acquiring a first signal from a noninvasive sensor configured to detect changes in blood volume or flow in a measurement region of the user, where the measured signal contains systolic time interval information;
• (b) applying a basal physiological detection model to the measured signal to determine the presence of a basal physiological state;
• (c) if the presence of a basal physiological state is detected, applying a basal cardiac fitness model to the measured signal to determine a cardiac fitness score;
• (d) reporting the cardiac fitness score.