University College London, Department of Medical Physics and Biomedical Engineering, England, United Kingdom.
University College London, Department of Computer Science, England, United Kingdom.
J Biomed Opt. 2019 Sep;24(12):1-6. doi: 10.1117/1.JBO.24.12.121907.
Since it was first demonstrated more than a decade ago, the single-pixel camera concept has been used in numerous applications in which it is necessary or advantageous to reduce the channel count, cost, or data volume. Here, three-dimensional (3-D), compressed-sensing photoacoustic tomography (PAT) is demonstrated experimentally using a single-pixel camera. A large area collimated laser beam is reflected from a planar Fabry–Pérot ultrasound sensor onto a digital micromirror device, which patterns the light using a scrambled Hadamard basis before it is collected into a single photodetector. In this way, inner products of the Hadamard patterns and the distribution of thickness changes of the FP sensor—induced by the photoacoustic waves—are recorded. The initial distribution of acoustic pressure giving rise to those photoacoustic waves is recovered directly from the measured signals using an accelerated proximal gradient-type algorithm to solve a model-based minimization with total variation regularization. Using this approach, it is shown that 3-D PAT of imaging phantoms can be obtained with compression rates as low as 10%. Compressed sensing approaches to photoacoustic imaging, such as this, have the potential to reduce the data acquisition time as well as the volume of data it is necessary to acquire, both of which are becoming increasingly important in the drive for faster imaging systems giving higher resolution images with larger fields of view.
自十多年前首次提出以来,单像素相机的概念已在许多需要或有利于减少通道数、成本或数据量的应用中得到应用。在这里,我们使用单像素相机实验演示了三维(3D)压缩感测光声断层摄影术(PAT)。大区域准直激光束从平面法布里-珀罗超声传感器反射到数字微镜器件上,数字微镜器件使用随机的哈德玛德基模式对光进行图案化,然后将光收集到单个光电探测器中。通过这种方式,记录了哈德玛德模式的内积和 FP 传感器厚度变化分布——由光声波引起的。使用基于模型的最小化和全变差正则化的加速近端梯度型算法,直接从测量信号中恢复出产生这些光声波的初始声压分布。通过这种方法,已经表明可以以低至 10%的压缩率获得成像体模的 3D PAT。这种基于压缩感知的光声成像方法有可能减少数据采集时间和所需采集的数据量,这在推动更快的成像系统以更高的分辨率和更大的视场获得更高分辨率的图像方面变得越来越重要。