RESEARCH ARTICLE

Calibration-free estimation algorithm for cuffless continuous blood pressure measurement based on ultrasonic devices

¹ School of Integrated Circuits and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
² Thoracic and Cardiovascular Surgery, Union Medical College Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430074, China
³ The State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074, China

^* Corresponding authors (emails: jfzang@hust.edu.cn (Jianfeng Zang); 1986XH0694@hust.edu.cn (Nianguo Dong); hctang1@hust.edu.cn (Hanchuan Tang))

Received: 29 April 2024
Revised: 2 July 2024
Accepted: 30 July 2024

Abstract

The rising global impact of hypertension calls for innovative approaches to achieve accurate and continuous blood pressure monitoring. Traditional cuff-based methods and pulse-transit-time (PTT) measurements face challenges, including discontinuity and the need for frequent calibration. Here, we introduce a paradigm-shifting method using a flexible ultrasonic array for calibration-free estimation. The conformal ultrasonic device, which integrates piezoelectric composites, copper electrodes, and a stretchable Polydimethylsiloxane substrate, precisely measures the radial artery diameter with an error margin controlled within 3%. The calibration-free algorithm, based on the Powalowski and Pensko model, establishes a dynamic correlation between arterial blood pressure and vessel diameter, with estimation errors within 1.2 ± 1.0 mmHg. Long-term monitoring over 30-day showcased the model’s stability. Our approach eliminates the need for frequent calibration, enhances accuracy, and offers a comprehensive insight into the dynamic relationship between blood pressure and vessel diameter. This innovation holds promise for revolutionizing continuous blood pressure monitoring, contributing to early detection and intervention in hypertensive individuals.