Wearable sensing band

A system for estimating the arterial travel distance (ATD) from a person's heart to a first portion of the person's body, comprising:

• one or more computing devices, said computing devices being in communication with each other whenever there is a plurality of computing devices;
• and
• an ATD estimating computer program having a plurality of sub-programs executable by the one or more computing devices, the one or more computing devices being directed by the sub-programs of the computer program to,
• receive directly-measured values of the ATD from a person's heart to a first portion of the person's body for a plurality of people,
• receive one or more body metrics for each of the plurality of people,
• correlate the ATD estimates with the body metrics, and
• generate a numerical model that estimates the ATD from a person's heart to a first portion of the person's body based on the body metric-ATD correlations.

A system for computing a pulse wave velocity (PWV) of a user, comprising:

• a wearable sensing band comprising,
• a strap which is attached to a first portion of the user's body,
• one or more primary electrocardiography (ECG) electrodes disposed on the strap such that whenever the wearable sensing band is worn by the user, the primary ECG electrodes are in electrical contact with said first portion of the user's body,
• one or more secondary ECG electrodes disposed on the strap such that whenever the wearable sensing band is worn by the user, the secondary ECG electrodes are electrically isolated from said first portion of the user's body and are positioned so as to be contacted by a second portion of the user's body located on the opposite side of the user's heart from said first portion of the user's body,
• one or more pulse pressure wave arrival (PPWA) sensors disposed on the strap such that whenever the wearable sensing band is worn by the user, the PPWA sensors are in proximity to or contacting said first portion of the user's body, wherein
• said primary and secondary ECG electrodes detect an ECG signal whenever the secondary ECG electrodes make electrical contact with said second portion of the user's body, and said PPWA sensors sense an arrival of a pulse pressure wave to said first portion of the user's body from the user's heart, and
• a computing device which executes program modules of a computer program, the computing device being directed by the program modules of the computer program to,
• estimate the time a pulse pressure wave leaves the user's heart using the ECG signal,
• establish the time said pulse pressure wave arrives at said first portion of the user's body using the sensed arrival of the pulse pressure wave,
• compute the pulse transit time (PTT) of a pulse pressure wave traveling through the user's arteries from the user's heart to said first portion of the user's body by subtracting the time the pulse pressure wave left the user's heart from the arrival time of the pulse pressure wave to said first portion of the user's body,
• obtain an estimate of the arterial travel distance (ATD) between the user's heart and said first portion of the user's body using a numerical model and values of prescribed body metrics associated with the user, wherein the numerical model estimates the ATD from a person's heart to a first portion of the user's body based on body metric-ATD correlations, and
• compute the pulse wave velocity (PWV) using the PTT and ATD estimate.