JMIR Publications

ABSTRACT

Background:

Noninvasive approaches to monitor blood pressure (BP), in light of their convenience and accuracy, have paved the way towards remote screening and management of hypertension. However, existing noninvasive methodologies—which operate on mechanical, electrical, and optical sensing modalities—have not been thoroughly evaluated in demographically and racially diverse populations. Thus, the potential accuracy of these technologies in the very populations where they could have the most impact has not been sufficiently addressed. This presents challenges towards clinical translation, due to concerns of perpetuating existing health disparities.

Objective:

Here, we present findings on the feasibility of a cuff-less, wrist-worn, pulse transit time (PTT) based device for monitoring BP in a diverse population.

Methods:

The diverse population was recruited through a collaborative effort with a non-profit working with medically underserved areas (MUA) in Georgia. We used our custom, multi-modal, wrist-worn device to measure the PTT through photoplethysmography—as the distal timing reference—and seismocardiography—as the proximal timing reference. In addition, we created a novel data-driven beat selection algorithm to reduce noise and improve the robustness of the method. We compared the wearable PTT measurements to those from a finger-cuff continuous BP device over the course of several perturbations used to modulate BP.

Results:

Our PTT-based wrist-worn device accurately monitors BP in a diverse population (N = 44 subjects) with a mean-absolute-difference (MAD) of 2.90 mmHg after calibration. We further show the ability of our device to capture commonly observed demographic differences in underlying arterial stiffness.

Conclusions:

Accurate BP estimation using a convenient wearable device can empower users and facilitate remote blood pressure monitoring in MUAs, thus providing widespread hypertension screening and management towards health equity.