A Smart Ring for Cuffless Blood Pressure to Reduce Health Disparities in People of Color

PROJECT SUMMARY/ABSTRACT Hypertension is the most prevalent cardiovascular risk factor and disproportionately responsible for adverse outcomes in African Americans. African Americans with hypertension are also more likely to be unaware of elevated blood pressures, which further exacerbates complications of cardiovascular disease. Thus, detection of accurate blood pressure in African Americans is a critical step towards alleviating hypertension disparate outcomes. The objective of this project is to create an unobtrusive cuffless blood pressure monitor for measurement and identification for masked hypertension in communities of color. Current state of the technology that incorporates cuffs is cumbersome and does not allow for passive/frequent measurements. The trends for cuffless solutions are primarily focused on photoplethysmography (PPG) which does not operate well on darker skin tones and on participants with higher BMIs. This project leverages bioimpedance as a sensing modality in the form of a finger-worn device, like smart rings. Our device provides robust and nearly continuous bioimpedance readings, corresponding to blood volume and hemodynamic changes, that will be translated to blood pressure using machine learning and AI algorithms. Bioimpedance does not have the limitations of PPG; it is insensitive to varying skin tones and has deep penetration capabilities and therefore a higher BMI (and a thicker layer of fat under the skin) does not impact the measurements. The principal focus of our investigation is to gain insights into masked hypertension with the objective of capturing blood pressure frequently during the day and at nighttime. Our proposed technology can help identify certain short-term dynamics inclusive of variations of blood pressure and allows effective monitoring of response to medication for African American in Atlanta, GA and African American and Latinx communities in College Station, TX. This project incorporates two aims. Aim 1 intends to validate the smart ring technology that has been developed at Texas A&M on African American and Latinx participants (N=60) with varying BMI in lab settings, with no known pre-existing condition beyond obesity, in presence of various blood pressure maneuvers (cold pressor, handgrip and exercise) and for three postures (supine, standing and sitting). Aim 2 expands the validation of our technology in African American patients (N=144) with and without a history of hypertension in Atlanta, GA in mixed lab and ambulatory settings with a unique focus to explore the reported phenomenon of masked hypertension and to advance technology acceptance and social relevance in communities of color. After nearly ten years of industrial and academic technology development to extract blood pressure indices using PPG, to our knowledge, this effort for the first time addresses the limited effectiveness of PPG on darker skin tones and those who have a higher BMI. The literature demonstrates the higher prevalence of hypertension in African American communities and among those who have obesity, which further calls for BMI independent technology development and validation.