On-Vessel Patch-sensor for Measuring Blood Flow

描述（由申请人提供）：没有血液，组织死亡。这个项目的目标是开发非常小的传感器——看起来像这样——可以平放在血管壁上，测量它的血流量。这种新设备被称为贴片传感器，STTR的第一阶段是通过制造一个贴片传感器，并在活体动物身上证明它的有效性，从而建立其概念验证。该装置的意义在于其在广泛的外科手术中的潜在作用。其中包括，用于急性用途，监测血管和整形外科重建、创伤和普通外科手术中关键的术后血流，以及用于长期用途，监测腿部和心脏的旁路移植（使用植入物为传感器供电并无线传输测量结果）。申请STTR的小型企业DVX开发了一种特殊的超声波换能器——衍射光栅换能器，“DGT’s”——由PZT压电陶瓷制成，当被平埋在移植物壁上时，这种换能器已经成功地测量了人工血管（即移植物）中的血流。美国国立卫生研究院医疗超声换能器技术资源是该项目的研究机构，它已经学会了制造高频压电聚合物换能器，这种换能器是薄而柔韧的薄膜，非常适合用于贴片传感器。压电聚合物不像压电陶瓷那样敏感，但它们的高频工作能力，利用高频超声的高散射，并且在血管上是共形的，因此它们拾取更多的散射信号，弥补了它们较低的灵敏度。DVX和南加州大学将共同设计、制造和测试一种动物高频压电聚合物衍射光栅换能器，以满足血流测量贴片传感器的目标。在验证了这一概念之后，他们打算在第二阶段为特定的临床应用开发这种技术的不同版本。该项目的目标是开发一种简单的传感器，可以应用于血管的侧面，并提供有关流经血管的血流量的关键信息。这将改善每年数百万手术患者的术后和长期护理。

DESCRIPTION (provided by applicant): Without blood, tissue dies. The goal of this project is to develop very small sensors - looking something like this, -- that can be placed flat on the wall of a blood vessel and measure its blood flow. This new device is called a patch-sensor, and this STTR Phase I is to establish its proof-of-concept by making one and demonstrating that it works in a living animal. The significance of this device is in its potential role in a wide range of surgical procedures. These include, for acute use, monitoring crucial post-operative blood flow in vascular and plastic surgical reconstructions, trauma and general surgery, and for long- term use, monitoring bypass grafts in the leg and heart (using an implant to power the sensor and wirelessly transmit the measurement results). DVX, the small business applying for the STTR, has developed special ultrasound transducers -- diffraction-grating transducers, "DGT's" -- made of PZT piezoceramic that have been successful in measuring blood-flow in artificial vessels, i.e. grafts, when embedded flat in the graft wall. The NIH Resource on Medical Ultrasonic Transducer Technology at USC, the research institution in this project, has learned to fabricate high frequency piezopolymer transducers that are thin, flexible films, ideal for patch sensors. Piezopolymers are not as sensitive as piezoceramics, but their capability for high frequency operation, to utilize the higher scattering of ultrasound at high frequencies, and to be conformal on vessels, so that they pick up more of the scattered signal, compensates for their lower sensitivity. Working together, DVX and USC will design, fabricate, and test in an animal high frequency diffraction-grating transducers of piezopolymer to meet the goal of a blood- flow measuring patch-sensor. Having proved the concept, in Phase II they intend to develop different versions of this technology for particular clinical applications. PUBLIC HEALTH RELEVANCE The goal of this project is developing a simple sensor that can be applied to the side of a blood vessel and provide crucial information about the amount of blood flowing through it. This will improve both post-operative and long-term care for millions of surgical patients a year.