As the most important organ of human body, heart has many measures and indicators to assess the cardiac function in clinic. Ventricular systolic time intervals (STIs) are of major relevance in providing crucial information regarding cardiovascular state. However, the existing measurement technologies are costly, complicated to operate, and also require contact sensors. Based on the human cardiovascular model and principle of Doppler cardiogram (DCG), the differential DCG (D-DCG) and quadratic D-DCG (QD-DCG) carry the aortic pressure (AP) information by which the STIs can be calculated. A 24-GHz digital dc-tuning Doppler radar sensor (DRS) has been implemented to detect the accurate DCGs. To assess the feasibility of contactless measurement of the STIs by DRS, clinical experiments and evaluations are carried out in the operation theater (OT). The preejection period (PEP) and the left ventricular ejection time (LVET) estimation results reached 95.23% and 93.12% accuracy, respectively, which indicates that the proposed method has great potential to be used for STIs estimation and could be convenient for patient home monitoring.

中文翻译：

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临床环境中基于多普勒心电图的人体收缩时间间隔的非接触式测量

心脏作为人体最重要的器官，临床上有许多衡量心脏功能的措施和指标。心室收缩时间间隔 (STI) 在提供有关心血管状态的关键信息方面具有重要意义。然而，现有的测量技术成本高、操作复杂，并且还需要接触式传感器。基于人体心血管模型和多普勒心电图 (DCG) 原理，微分 DCG (D-DCG) 和二次 D-DCG (QD-DCG) 携带主动脉压 (AP) 信息，通过该信息可以计算 STI。已实施 24 GHz 数字直流调谐多普勒雷达传感器 (DRS) 来检测准确的 DCG。为了评估 DRS 对 STI 进行非接触式测量的可行性，在手术室 (OT) 进行了临床实验和评估。