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

University Of New Mexico, Albuquerque NM

Investigators

Abstract

0853618 Chen This 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.