DORMOUSE: Detection Of Reflected Microscopic Optical UltraSound Emission

博士项目的目的：研究一种使用光来映射超声波的新方法建立一个系统来执行远距离高分辨率超声检测基于这项新开发的技术演示活的受试者的成像项目描述任何科幻迷都知道高分辨率全身成像的力量；医院病床上的患者被看不见的传感器探测，产生他们身体的虚拟重建，盘旋在床上，被医生操纵、调查和检查。虽然现有的CT、MRI、PET和SPECT等全身成像方法可以达到这一理想，但我们仍然缺乏一种真正的、快速、高分辨率、非侵入性和长期监测安全的全身成像技术。超声成像是实现这一全身成像理想的最佳技术；它是非侵入性的，可以分辨小至100微米的特征，并且具有极高的数据吞吐量。然而，它传统上受到缺乏高分辨率声学发射器和接收器的限制。与可以记录数亿像素数据的摄像头不同，超声波传感器的分辨率最高限制在几千像素，通常不到一百像素。此外，超声换能器必须与患者保持接触，因为超声波不能有效地在空气中传播。创造全身扫描仪的梦想需要一种方法来弥合这一差距，并使用百万像素分辨率的换能器阵列。对我们来说，幸运的是，光可以有效地通过空气传输，并可以用来为声波成像。此外，光可以以百万像素的分辨率进行图案化，足以快速成像成人人体的大部分，前提是有方法将激光信号转换为声学信号，然后再转换回来。在这个项目中，将开发一种新型的方法，基于对光纤中的光进行成像。当声波通过时，这种光会发生变化，这就是我们能够检测到光学信号的原因。在图中可以看到拟议中的仪器正在运行的图像。该学生将成为正在进行的开发高分辨率光学超声系统的大型合作的一部分。他们将负责开发一种可以缩放到大量像素的快速超声波探测器(基于硅光电倍增管阵列和数字采集卡)，并使用它来制作可以成像声场的系统原型。然后，该项目将继续创建一个小型样机，它可以在几米的范围内检测超声波，初始分辨率为4x4像素，但只需添加更多探测器就可以任意缩放。

Aim of the PhD Project:Investigate a new method for mapping ultrasound waves using lightBuild a system to perform stand-off high-resolution ultrasound detectionDemonstrate imaging of a live subject based on this newly-developed technologyProject DescriptionAny science fiction fan knows the power of high-resolution whole-body imaging; a patient on a hospital bed is probed by unseen sensors, producing a virtual reconstruction of their body, which hovers over the bed, being manipulated, investigated and examined by the doctor. While existing whole-body imaging methods like CT, MRI, PET and SPECT can get some way towards this ideal, we still lack a truly whole-body imaging technique that is fast, high-resolution, non-invasive and safe for long-term monitoring.Ultrasound imaging is the best technology for reaching this whole-body imaging ideal; it is non-invasive, can resolve features as small as 100 micrometres, and has extremely high data throughput. Nevertheless, it has traditionally been limited by the lack of high-resolution acoustic transmitters and receivers. Unlike cameras, which can record data with hundreds of megapixels of resolution, ultrasound transducers are limited to a few thousand pixels at most, and usually fewer than one hundred. Furthermore, ultrasound transducers must remain in contact with the patient, since ultrasound doesn't travel through air efficiently. The dream of creating a whole-body scanner requires a means of bridging this air-gap, and with a megapixel-resolution transducer array.Fortunately for us, light is transmitted through air efficiently, and can be used to image acoustic waves. Furthermore, light can be patterned with megapixel resolution, sufficient to image a large fraction of an adult human body quickly, provided there is a way to turn the laser signal into an acoustic one and back again. In this project, a new type of approach will be developed, based on imaging the light in an optical fiber. This light changes when a sound wave passes, which is what allows us to detect the optical signal. An image of the proposed instrument in operation can be seen in the Figure.The student will be part of a large ongoing collaboration to develop high-resolution optical ultrasound systems. They will be responsible for developing a fast ultrasound detector that can be scaled to large numbers of pixels (based on a silicon photomultiplier array and digital capture card) and using it to prototype a system that can image an acoustic field. The project will then progress to creating a small example instrument which can detect ultrasound at a range of several meters, with an initial resolution of 4X4 pixels, but which can be scaled arbitrarily just by adding more detectors.