Wearable Micro-Structured Tonometric Sensor Patches for 24-Hour Ambulatory Blood Pressure Monitoring

项目总结/摘要 高血压（BP）是心血管疾病死亡率的最大风险因素。由于井- 临床血压测量的已知局限性，使用自动袖带装置进行24小时动态血压监测 已成为高血压诊断的金标准方法。由于周期性的通货膨胀和通货紧缩 即使在夜间，袖带装置也会对患者造成干扰， BP.因此，无袖带的BP监测设备正在被广泛追求。脉搏传导时间（PTT），时间延迟 对于在两个动脉部位之间传播的压力波，代表了最有希望的无袖带BP 测量原理然而，在现有的PTT测量中存在几个关键障碍，例如： 低于标准的传感器灵敏度;（ii）传感器粘附性差;（iii）难以将PTT测量值转换为BP 读数;（iv）难以获得舒张压（DP）和收缩压（SP）测量值。解决 这些问题，这项工作的总体目标是联合收割机动脉张力和PTT原则，以实现 无袖带24小时动态血压监测这将通过放置两个可穿戴的眼压传感器来实现 在动脉部位（近端和远端），并收集高保真眼压波形以及PTT值。 我们在这项工作中的创新包括：（a）整合离子液体和微结构（可以容纳 压力下的离子），以增强灵敏度和动态范围;（B） 在传感器基底处结合微柱（模仿壁虎的脚）以促进粘附并改善 捕获波形的保真度;（c）用预先构建的PTT-BP校准眼压波形 （d）校准眼压波形以提取DP和SP两者 通过利用动脉张力计和BP波形的相似形状来连续地测量血压。具体目标是： (1)开发可穿戴传感器以获得高保真的眼压波形;（2）促进粘附 可穿戴贴片;（3）开发基于PTT的校准，用于提取DP和SP;以及（4）验证 人类研究中的系统。我们预期的结果是一个准确的，无袖带，24小时BP监测系统。 该项目的成功完成可以为动态血压监测和术后血压监测带来新的临床实践。 手术低血压监测。

PROJECT SUMMARY/ABSTRACT High blood pressure (BP) is the single largest risk factor for cardiovascular disease mortality. Due to the well- known limitations of clinic BP measurement, 24-hour ambulatory BP monitoring with automatic cuff devices has emerged as the gold standard method for hypertension diagnosis. Due to periodic inflation and deflation even at nighttime, the cuff devices are disruptive to patients and could diminish the clinical value of nighttime BP. Hence, cuff-less BP monitoring devices are being widely pursued. Pulse transit time (PTT), the time delay for the pressure wave to travel between two arterial sites, represents the most promising cuff-less BP measurement principle. However, there are several critical barriers in exiting PTT measurements such as: (i) subpar sensor sensitivity; (ii) poor sensor adhesion; (iii) difficulty in converting PTT measurements into BP readings; (iv) difficult in obtaining both diastolic BP (DP) and systolic BP (SP) measurements. To address these issues, the overall objective of this work is to combine arterial tonometry and PTT principles to achieve cuff-less 24-hour ambulatory BP monitoring. This will be achieved by placing two wearable tonometric sensors at arterial sites (proximal and distal) and collecting high-fidelity tonometric waveforms as well as PTT values. Our innovations in this work include: (a) integrating ionic liquid and microstructures (which can accommodate ions under pressure) in piezo-capacitive sensor to enhance both the sensitivity and dynamic range; (b) incorporating micropillars (mimicking gecko’s feet) at the sensor substrate to promote adhesion and improve the fidelity of captured waveforms; (c) calibrating tonometric waveforms with pre-constructed PTT-BP relationships (via postural changes); (d) calibrating tonometric waveforms to extract both DP and SP continuously by leveraging the similar shape of arterial tonometric and BP waveforms. The specific aims are: (1) to develop wearable sensors to obtain high-fidelity tonometric waveforms; (2) to promote the adhesion of wearable patches; (3) to develop PTT-based calibration for extracting both DP and SP; and (4) to validate the system in human studies. Our expected outcome is an accurate, cuff-less, 24-hour BP monitoring system. Successful completion of this project can lead to new clinical practices for ambulatory BP monitoring and post- surgery hypotension surveillance.