Wearable Electrostrictive Row-Column Ultrasound Arrays for Longitudinal Echocardiography

项目摘要/摘要 在重症监护病房(ICU)入院的患者中，休克(低血压)导致临床 以及由于心输出量不足而导致组织低灌流的生化证据，临床医生通常寻求 来评估和监测心脏功能，但所有可用的有创和无创方法都有 重大限制和/或风险。评估心输出量和休克状态的金标准方法是 插入静脉导管并穿过右侧的肺动脉导管(PAC) 将心脏送入肺动脉。这种方式的优点是它提供了关于权利的信息 和左心压，并允许通过热稀释技术计算心输出量。它的 缺点包括造成血管损伤的潜在风险的侵入性。此外，心脏 在常见的心律失常(房颤)和瓣膜病变(三尖瓣外)中，输出不准确 反流)，只提供整体心脏功能的信息，没有关于左侧和左侧的直接信息 右心功能。无创心输出量监测器(NICOM)使用专有的生物阻抗或动脉 曲线下的直线面积算法估计心输出量。虽然这些都是微创的，但它们有 在心源性休克患者中没有得到很好的验证，并且没有提供关于左心和右心功能的信息。 最后，护理点超声(Pocus)允许超声心动图评估左心和右心功能， 但它不太适合于评估心功能的连续或暂时趋势，因为它需要 临床医生在床边采集图像。一种可穿戴的超声波探头，可以免提 患者的纵向成像将被证明在ICU环境中具有相当大的价值。 在这项提案中，我们介绍了一种全新的可穿戴超声技术，偏压敏感型电致伸缩顶部- 正交至底部电极(TOBE)阵列。这些Tobe阵列提供从2D的每个元素的读数 通过偏置控制和发送-接收控制仅对行和列进行阵列，而不需要布线 来自每一种元素。使用新的读出方法，这些阵列将被演示以实现图像质量 可与线性阵列媲美，但具有完整的电子3D扫描能力。不同于矩阵探测器，它依赖于 在复杂的微波束形成器上，我们的方法更简单，但允许高级成像模式，如 每秒数千帧的超快成像。我们建议发展这种超快成像 可穿戴TOBE探头用于角不可知流动估计和纵向电子跟踪右翼的模式 和左心功能。角度不可知的流动估计避免了由于未知的多普勒角和 减少了手动探头定位的需要。在这项建议中，我们的目标是进一步开发换能器 技术、接口电子学和成像方法，以在模体中实现角度不可知的流动成像， 然后是人类第一次成像。我们的目标是为未来的高级研究建立可行性数据 纵向监测心输出量、射血分数、肺动脉压等。

Project Summary / Abstract In patients admitted to intensive care units (ICUs) with shock (low blood pressure) that results in both clinical and biochemical evidence of tissue hypoperfusion due to inadequate cardiac output, clinicians commonly seek to assess and monitor cardiac function, but all available invasive and non-invasive methodologies have significant limitations and/or risk. The gold standard method to assess cardiac output and shock states is a pulmonary arterial catheter (PAC) which is inserted through a venous canula and passes through the right side of the heart into the pulmonary artery. The advantages of this modality are that it provides information on right and left heart pressures, and allows for the calculation of cardiac output via thermodilution techniques. Its disadvantages include the invasive nature resulting the potential risk of vascular injury. Moreover, cardiac outputs are inaccurate in common cardiac arrhythmias (ex atrial fibrillation) and valvular lesions (ex tricuspid regurgitation), and only provides information on overall cardiac function without direct information on left and right heart function. Non-invasive cardiac output monitors (NICOMs) use proprietary bio-impedance or arterial line area under the curve algorithms to estimate cardiac output. While these are minimally invasive, they have not been well validated in patients in cardiogenic shock and provide no information on left and right heart function. Finally, point of care ultrasound (POCUS) allows echocardiographic evaluation of left and right heart function, but it is not well suited for evaluation of continuous or temporal trends in cardiac function given it requires a clinician to acquire images at the bedside. A wearable ultrasound probe that would enable hands-free longitudinal imaging of patients would prove to be of considerable value in the ICU environment. In this proposal we introduce a radically new wearable ultrasound technology, bias-sensitive electrostrictive top- orthogonal-to-bottom electrode (TOBE) arrays. These TOBE arrays offer readout from every element of a 2D array through biasing control and transmit-receive control of only rows and columns, rather than require wiring from every element. With novel readout approaches, these arrays will be demonstrated to achieve image quality comparable to a linear array, but with full electronic 3D scanning capabilities. Unlike MATRIX probes that rely on complicated micro-beamformers, our approach is simpler, yet allows for advanced imaging modes such as ultrafast imaging at thousands of frames per second. We propose the development of such ultrafast imaging modes with wearable TOBE probes for angle-agnostic flow estimation and longitudinal electronic tracking of right and left heart function. The angle-agnostic flow estimation avoids errors due to unknown Doppler angles and mitigates the need for manual probe positioning. In this proposal, we aim to further develop the transducer technology, interfacing electronics, and imaging methods to enable angle-agnostic flow imaging in phantoms, then with first-in-human imaging. We aim to establish feasibility data for future research into advanced longitudinal monitoring of cardiac output, ejection fractions, pulmonary artery pressure, etc.