Integrating light with sound: a photoacoustic flashlight for 3D brain imaging

0853618本提案旨在开发和表征用于大脑实时3D光声成像(PAI)的具有红外光传输的电容式微机械超声换能器(CMUT)阵列。拟议的“光声手电筒”将实现对新生血管的高分辨率解剖成像，以及基于氧合血红蛋白变化的功能成像，氧合血红蛋白是大脑中红外光的主要吸收者。它还具有分子成像的潜力，这将需要引入光学造影剂。在该装置中，使用光纤传输和透镜聚焦实现的光源提供脉冲光能，该脉冲光能照亮目标组织并刺激基于热弹性的声学信号。具有悬浮电极膜的微电容传感元件阵列通过膜的变形引起的电容变化来检测辐射声波。研究目标包括评估不同的光与CMUT传感元件集成的设计，表征与PAI兼容的CMUT阵列原型，开发用于实时PAI的板级并行波束形成，以及在模体、神经束和大鼠大脑中评估CMUT原型设备。

0853618ChenThis proposal is for the development and characterization of a capacitive micromachined ultrasonic transducer (CMUT) array with IR light delivery for use in real-time 3D photoacoustic imaging (PAI) of the brain. The proposed "photoacoustic flashlight" would enable high resolution anatomical imaging of the neuovasculature, and functional imaging based on changes in oxygenated hemoglobin, which is the primary absorber of IR light in the brain. It also holds potential for molecular imaging, which would require the introduction of optical contrast agents. In this device, a light source implemented using optical fiber delivery and lens focusing provides pulsed optical energy that illuminates the target tissue and stimulates a thermoelastic-based acoustic signal. An array of micro-capacitor sensing elements with suspended electrode membranes detect the radiated acoustic wave via change in capacitance due to the deformation of the membranes. The research objectives include evaluation of different designs for integrating light with CMUT sensing elements, characterization of prototype PAI-compatible CMUT arrays, development of board-level parallel beamforming for real-time PAI, and evaluation of prototype CMUT devices in phantoms, nerve bundles and rat brain.