Validation Study of CART BP as a Wearable Cuffless Blood Pressure Monitor

Overview

This study aims to evaluate the accuracy of the CART BP, a medically approved ring-type blood pressure monitor, in comparison to the traditional auscultatory method using a dual-head stethoscope. The comparison is conducted in accordance with the 2023 European Society of Hypertension (ESH) Recommendations, focusing on patients with suspected hypertension or hypotension. The evaluation includes accuracy measurements across various postures and during different exercise periods.

There is a non-invasive technique called Photoplethysmography (PPG) that overcomes the limitations of traditional auscultatory and oscillometric methods. Photoplethysmography uses light-emitting diodes (LEDs) to illuminate human tissue, specifically targeting blood vessels, and employs sensors to measure the volume of blood flowing through the tissue. This technique can be applied to various parts of the small arterial system in the human body, enabling cuffless blood pressure measurement. As a result, it simplifies blood pressure monitoring for subjects and allows for extended observation periods. With the advancement of cuffless blood pressure monitors, the European Society of Hypertension (ESH) has established recommendations to ensure accurate measurements. The recommendations consider variations in measurement height and compare accuracy after blood pressure is elevated through aerobic exercise or low-intensity repetitive exercises, such as handgrip exercises. This study aims to follow the 2023 European Society of Hypertension recommendations by measuring blood pressure with the arm positioned vertically more than 20 centimeters below the standard position and comparing the results obtained after repeated handgrip exercises with those obtained using the standard method.