Investigate a practical high sensitivity PVDF multielement SBCT ultrasound transd

描述（由申请人提供）：医用超声换能器的世界市场每年超过10亿美元，医生的平均成本超过每个换能器5,000美元。换能器几乎完全由锆钛酸铅（PZT）制成，这种陶瓷具有不良的窄带宽特性，限制了图像的轴向分辨率。电容式微机械超声换能器（CMUT）在过去十年中的挑战并没有对PZT在这个大市场中的排他性产生任何影响。这个应用程序是用聚偏二烯（PVDF）制造换能器，基于一个经过验证的模型和形式分析，该模型和形式分析发现，多层低成本PVDF以独特的模式堆叠（切换巴克码换能器（SBCT））时，保留了材料的极宽带宽，并以创新的电子耦合方法克服了PVDF的低介电特性。进一步预测了11层SBCT的脉冲回波灵敏度等于或优于PZT。光刻生产的多元件换能器层将由新开发的“纳米胶”粘合，这种“纳米胶”提供纳米层分离，并将通过商用的拾取设备促进每小时数千个换能器的简单低成本组装。通过所提出的方法制造的换能器可以在所有25种应用中取代PZT换能器，这些换能器目前正在生产中，从妇产科到一次性心脏内换能器。这种方法还提高了分辨率、灵敏度和成本。简单的光刻方法将定义换能器的尺寸、元件数量、形状和用途等特性。这将允许许多定制换能器以非常低的成本构建从100 KHz到40 MHz的频率。由于更高的带宽，斑点是当今超声图像的一个特征，它将变得更加详细，但同时频率复合也将变得更加有效，呈现出更清晰的图像，整体分辨率更高，穿透度更深。由于带宽的提高，弹性成像等方法将大大提高诊断的特异性。本项目将构建13层15 MHz SBCT PVDF换能器，可与公司生产的15 MHz PZT换能器（60%带宽）进行比较，PZT换能器主要用于临床前弹性成像和光声学，可以定量地单独评估传输和接收的带宽。这种提议的方法将使传感器的建造成本仅为几十美元，这大大降低了预计医生的成本，而且这一点，加上预计在分辨率上的收益，可以预期对医疗保健的质量和成本产生重大影响。

DESCRIPTION (provided by applicant): The world market for medical ultrasound transducers exceeds one billion dollars annually, with an average cost to the physician exceeding $5,000 for each transducer. Transducers are made almost exclusively from lead zirconate titanate (PZT), a ceramic which has undesirable narrow bandwidth characteristics that limit the image's axial resolution. A challenge by Capacitive Micromachined Ultrasonic Transducers (CMUT) over the last ten years has not made any impact on PZT's exclusivity in this large market. This application, to make transducers from Polyvinylidene (PVDF), is grounded in a proven model and formal analysis which finds that multiple layers of low cost PVDF when stacked in a unique pattern (Switched Barker Code Transducer (SBCT)), preserves the material's extremely wide bandwidth and overcomes the PVDF's low dielectric characteristics in an innovative electronic coupling method. The SBCT modeling further predicts the pulse-echo sensitivity of an eleven layer SBCT to be equal or better than PZT. The lithographically produced multi-element transducer's layers will be bonded by newly developed "nanoglue" which provides a nanometer layer separation and will facilitate the simple low cost assembly of thousands of transducers per hour by commercially available pick and place equipment. Transducers manufactured by the proposed method can replace PZT transducers in all 25 of the applications where transducers are in production today, from OB/GYN to disposable intra cardiac transducers. This method also yields improvements in resolution, sensitivity, and cost. Simple lithographic methods will define the transducer's characteristics of size, number of elements, shape and use. This will allow many custom transducers to be constructed at very low cost for frequencies from 100 KHz through to 40 MHz. The speckle that is a characteristic of today's ultrasound images will become more detailed due to the much higher bandwidth, but simultaneous frequency compounding will also become much more effective rendering clearer images of overall higher resolution and deeper penetration. Modalities such as elastography will benefit greatly in diagnostic specificity from this bandwidth improvement. A thirteen layer 15 MHz SBCT PVDF transducer will be constructed in this project which can be compared with the company's production 15 MHz PZT transducer (60% bandwidth) that is primarily used in preclinical elastography and photoacoustics, where bandwidth of transmission and reception can be quantitatively and separately evaluated. This proposed method will allow transducers to be constructed for tens of dollars which greatly reduces the projected physician's cost, and this, plus the projected gains in resolution, can be expected to have a major effect on the quality and cost of health care. PUBLIC HEALTH RELEVANCE: In this project medical ultrasound transducers will be constructed by a multilayer plastic (PVDF) using Barker Coded arrangement that provides equivalent sensitivity to today's state of the art ceramic (PZT) transducers at less than 1/10 of the cost and provides extremely high bandwidth for superior axial resolution that wil find application in the new fields of elastography and photoacoustics. The method can be applied to all transducers of all applications by low cost lithography and production an be accommodated in thousands per hour by commercial electronic pick and place machines. The current $ 1 billion spent on medical transducers per year will be greatly reduced while providing clearer, higher resolution ultrasound images with higher diagnostic use.