Portable dehydration monitoring system

A method for determining a hydration status of a person comprising:

• obtaining at least one photoplethysmography (PPG) reading from the person using a camera and associated lighting source of an electronic device prompting the person to breathe at a first selected pace for a first selected duration while the person is in a seated position;
• measuring the person's heart rate variability (HRV) during the first selected duration to obtain a first HRV value;
• prompting the person to rise to a standing position;
• prompting the person to breathe at a second selected pace for a second selected duration while the person is in the standing position;
• measuring the person's HRV during the second selected duration to obtain a second HRV value;
• calculating a difference between the first HRV value and the second HRV value to generate a daily score;
• calculating a baseline value for the person according to historical HRV data and storing the baseline value at the electronic device;
• and
• subtracting a baseline value from the daily score to obtain a hydration score.

A method for determining a hydration status of a person comprising:

• obtaining at least one of a photoplethysmography (PPG) measurement value or an electrocardiogram (ECG) measurement value from the person;
• transmitting the obtained at least one PPG measurement value or ECG measurement value to an electronic device;
• prompting the person to breathe at a first selected pace for a first selected duration while in a first postural position;
• measuring the person's heart rate variability (HRV) during the first selected duration to obtain a first HRV value;
• prompting the person to change from the first postural position to a second postural position;
• prompting the person to breathe at a second selected pace for a second selected duration while in the second postural position;
• measuring the person's HRV during the second selected duration to obtain a second HRV value;
• calculating a difference between the first HRV value and the second HRV value to generate a daily score;
• determining a hydration score based at least in part upon the daily score;
• and
• storing one or more sets of hydration status information at the electronic device.