Development of a microresonator based photoacoustic imaging system

1)简要介绍本研究的背景及潜在影响。本文将设计和优化新的光声成像系统，首先开发一种新的询问方法和一种新的制造方法，以提高现有聚合物微谐振腔超声传感器的灵敏度。潜在的影响包括但不限于，实现最先进的聚合物传感器灵敏度，实现更深的成像深度等。2)目标和目标总体目标将是开发和应用用于实际光声组织成像的微谐振器传感器。这将包括几个主题，包括发展新的审讯方案，制造方法和进行光声成像实验。3)研究方法的新颖性聚合物微谐振器超声传感器可以提供极高的声灵敏度，因为它们提供了高度的光学限制，从而产生非常高的q因子。然而，这也使他们易受热效应由于腔内的审问激光的吸收。例如，它会产生干涉仪传递函数（ITF）的畸变，从而降低了找到最佳偏置波长的精度，从而降低了灵敏度。在这项研究中，将开发一种新的方法来减轻这种情况，以减少总吸收能量并最大限度地减少加热。此外，通过仔细控制询问激光占空比能够更准确地识别偏置波长，这也可能允许使用更高的询问激光功率，从而增加声学探测灵敏度。除了考虑传感器的问题外，还可以探索新的传感器制造方法，例如使用具有更高声灵敏度的低模量弹性体或产生更高q因子的超高精细玻璃腔。在确定最佳询问方案和传感器制造方法之后，将开发一个实验室光声成像系统，该系统将允许单个传感器在各种检测几何形状（平面，圆柱形和球形）上进行扫描，以便评估相对于传统压电接收器的成像性能。该系统将用于识别最优的探测器特性、传感器数量、扫描参数。这些将用于设计一个实用的多元素成像系统，该系统将在模拟幽灵的组织、离体组织和体内组织上进行构建和测试。4)与EPSRC的战略和研究领域保持一致。该项目与2019年交付计划中的ERSRC研究和创新重点保持一致。基于光声成像的新型传感器是一种新型的混合成像方式，将在临床医学、临床前研究和基础生物学中广泛应用，用于研究癌症、心血管疾病、微循环异常等疾病。该项目将实现的目标不仅是通过实现具有卓越灵敏度性能的最先进传感器来提供更好的生活质量，而且还将通过在询问系统中用更经济实惠的脉冲激光取代连续波长激光来显著降低成本，从而确保更高标准的可负担医疗保健。5)涉及任何公司或合作者

1) Brief description of the context of the research including potential impactA new photoacoustic imaging system will be designed and optimised by first developing a new interrogation method and a new fabrication method to enhance the sensitivity of present polymer microresonator ultrasound sensors. The potential impact includes but not limited to, achieving state-of-art polymer sensor sensitivity, enabling deeper imaging depth, etc.2) Aims and objectivesThe overall aim will be to develop and apply microresonator sensors for practical photoacoustic tissue imaging. This will encompass several topics including the development of novel interrogation schemes, fabrication methods and undertaking photoacoustic imaging experiments.3) Novelty of the research methodologyPolymer microresonator ultrasound sensors can provide extremely high acoustic sensitivity on account of the high degree of optical confinement they provide which yields very high Q-factors. However, this also makes them susceptible to thermal effects due to absorption of the interrogation laser light within the cavity. For example, it can produce distortion of the interferometer transfer function (ITF) which reduces the accuracy with which the optimum bias wavelength can be found resulting in reduced sensitivity. In this research, a new approach to mitigating this will be developed to reduce the total absorbed energy and minimise heating. As well as enabling a more accurate identification of the bias wavelength via careful control of the interrogation laser duty cycle, this may also allow higher interrogation laser powers to be used thus increasing acoustic detection sensitivity. As well as considering the sensor interrogation, new sensor fabrication methods may be explored, for example the use of low modulus elastomers that provide higher acoustic sensitivity or ultra-high finesse glass cavities that yield higher Q-factors. Following identification of the optimal interrogation scheme and sensor fabrication method, a laboratory photoacoustic imaging system that will permit a single sensor to be scanned over various detection geometries (planar, cylindrical and spherical) will be developed in order to assess imaging performance relative to conventional piezoelectric receivers. This system will be used to identify the optimal detector characteristics, number of sensors, scan parameters. These will be used to inform the design of a practical multi-element imaging system that will be constructed and tested on tissue mimicking phantoms, ex vivo tissue and in vivo.4) Alignment to EPSRC's strategies and research areasThis project is in alignment with ERSRC research and innovation priorities in the delivery plan 2019. The new sensor based on photoacoustic imaging, a novel hybrid imaging modality, will be highly beneficial to a wide variety of applications in clinical medicine, preclinical research, and basic biology for studying cancer, cardiovascular disease, abnormalities of the microcirculation and other conditions. What will be achieved in this project is not only about delivering a better quality of life by achieving a state-of-the-art sensor with superior sensitivity performance but also about ensuring higher standards of affordable healthcare by reducing cost significantly by substituting continuous wavelength laser with much more affordable pulse laser in the interrogation system.5) Any companies or collaborators involvedNone