Department of Electrical and Computer Engineering, California State University, Fresno, CA 93740, USA.
Electronics and Telecommunications Research Institute, Daejeon 34129, Republic of Korea.
Sensors (Basel). 2023 Jul 19;23(14):6517. doi: 10.3390/s23146517.
This paper proposes to remotely estimate a human subject's blood pressure using a millimeter-wave radar system. High blood pressure is a critical health threat that can lead to diseases including heart attacks, strokes, kidney disease, and vision loss. The commonest method of measuring blood pressure is based on a cuff that is contact-based, non-continuous, and cumbersome to wear. Continuous remote monitoring of blood pressure can facilitate early detection and treatment of heart disease. This paper investigates the possibility of using millimeter-wave frequency-modulated continuous-wave radar to measure the heart blood pressure by means of pulse wave velocity (PWV). PWV is known to be highly correlated with blood pressure, which can be measured by pulse transit time. We measured PWV using a two-millimeter wave radar focused on the subject's chest and wrist. The measured time delay provided the PWV given the length from the chest to the wrist. In addition, we analyzed the measured radar signal from the wrist because the shape of the pulse wave purveyed information on blood pressure. We investigated the area under the curve (AUC) as a feature and found that AUC is strongly correlated with blood pressure. In the experiment, five human subjects were measured 50 times each after performing different activities intended to influence blood pressure. We used artificial neural networks to estimate systolic blood pressure (SBP) and diastolic blood pressure (SBP) with both PWV and AUC as inputs. The resulting root mean square errors of estimated blood pressure were 3.33 mmHg for SBP and 3.14 mmHg for DBP.
本文提出了一种使用毫米波雷达系统远程估计人体血压的方法。高血压是一种严重的健康威胁，可导致心脏病、中风、肾病和视力丧失等疾病。测量血压最常见的方法是基于袖带，这种方法是接触式的、不连续的，佩戴起来很麻烦。连续远程监测血压可以促进心脏病的早期发现和治疗。本文研究了使用毫米波频率调制连续波雷达通过脉搏波速度 (PWV) 来测量心脏血压的可能性。脉搏波速度与血压高度相关，而脉搏波传导时间可以测量血压。我们使用两毫米雷达波聚焦在对象的胸部和手腕处来测量 PWV。测量得到的时间延迟提供了从胸部到手腕的 PWV。此外，我们还分析了从手腕测量到的雷达信号，因为脉搏波的形状提供了有关血压的信息。我们研究了曲线下面积 (AUC) 作为特征，并发现 AUC 与血压高度相关。在实验中，五名志愿者在进行了不同旨在影响血压的活动后，每人被测量了 50 次。我们使用人工神经网络，以 PWV 和 AUC 作为输入，来估计收缩压 (SBP) 和舒张压 (DBP)。估计血压的均方根误差分别为 SBP 为 3.33mmHg，DBP 为 3.14mmHg。
