Ultrasonic phantom materials for equipment calibration

用于高频生物医学研究的超声波扫描系统的用户需要由模拟组织材料制成的“模体”，以便校准超声信号并理解设备获取的图像。如果没有这样的幻影，比较不同实验室的实验结果或将研究结果转移到临床环境中是不现实的。我们在这个项目中的目标是开发一种新的稳定的体模材料，它对频率高达50 MHz的超声波的响应类似于人体组织。一旦这种组织模拟材料被开发出来，我们的工业合作伙伴FujiFilmVisualSonics也可以使用它来组装更复杂的体模，这些体模可以用于技术人员培训或解释超声波图像。 该项目的关键挑战是获得适当水平的超声波速度、衰减和密度，以模拟人体组织--所有这些都在单一、稳定的材料中完成。通过在制造响应过程中调整聚合物链的交联量，我们打算调整超声波衰减，使其与几乎任何特定的生物医学组织保持一致。 还在开发一种将细钨丝和尼龙纤维嵌入模体材料内的直线以用于设备校准的工艺；这些靶子将为设备提供适当的校准测试，以确认其灵敏度和分辨率满足要求的规格。然后，可以放心地使用Visualsonics设备来表征真实组织样本中的任何异常，并允许准确评估研究结果。

Users of ultrasonic scanning systems for high frequency biomedical research require "phantoms" made of tissue-mimicking materials in order to calibrate the ultrasonic signals and understand the images acquired by the equipment. Without such phantoms, it is not practical to compare experimental results from different laboratories, or to transfer research findings to a clinical setting. Our objective in this project is to develop a new stable phantom material that has a similar response to ultrasound to that of human tissue at frequencies up to 50 MHz. Once this tissue-mimicking material has been developed, it can also be used by our industrial partner FujiFilmVisualSonics to assemble more complex phantoms that can be used for technician training or interpretation of ultrasonic images. The key challenge in this project is to attain appropriate levels of ultrasonic velocity, attenuation, and density to mimic human tissue - all within a single, stable material. By adjusting the amount of cross-linking of polymer chains during the manufacturing response, we intend to adjust the ultrasonic damping to bring it in line with almost any specified biomedical tissue. A process to embed thin tungsten wire filaments and nylon fibers in straight lines inside the phantom material for equipment calibration purposes is also being developed; these targets will provide a suitable calibration test for equipment to confirm that its sensitivity and resolution meet required specifications. The VisualSonics equipment could then be used with confidence to characterize any anomalies in real tissue samples, and allow research findings to be accurately evaluated.