180. the characterization of novel , affordable and compact led-based photoacoustic imaging system to facilitate molecular imaging
Research Institute Affiliation: Graduate Program in Materials Science and Engineering
Faculty Advisor(s): Jesse V. Jokerst
Name: Ali Hariri
Grad Year: 2021
Photoacoustic imaging (PAI) is an efficient, non-invasive, non-ionizing and promising imaging modality which is based on optical excitation and ultrasound detection. This modality can be considered as a combination of optical and acoustic imaging methods. This high-resolution modality has been used to image endogenous chromophores (melanin, hemoglobin etc.) and exogenous contrast agents in different medical applications including molecular imaging, oncology, ophthalmology, cardiology and neurology. There is a growing need to design light emitting diodes(LED) based, dual modality (ultrasound/photoacoustic), affordable and portable handheld probe which is offering real-time structural (ultrasound) and functional (photoacoustic) imaging for clinical applications. In this study system specifications, light source characterizations, photoacoustic spatial/temporal resolution and penetration depth of LED-based PAI system is described. Feasibility of in-vivo molecular imaging of system is also presented. In aforementioned handheld design two units of LED arrays are attached to both side of ultrasound transducer. LED pulse repetition rate is tunable between 1KHz, 2KHz, 3KHz and 4KHz. According to LED low excitation energy, averaging method is critical to improve strength of photoacoustic signal while this method decrease the frame rate as well. Various number of averaging within different repetition rates has been designed in data acquisition unit. These numbers provide frame rates from 0.15Hz to 30Hz. Axial resolution of 0.268mm and lateral resolution of 0.59mm is measured for this novel photoacoustic system. in terms of penetration depth, LED based photoacoustic system has capability to detect optical absorber (graphite pencil lead) in depth of 3.2cm. This system is also utilized to image novel photoacoustic contrast agents as well.
Industry Application Area(s)
Electronics/Photonics | Life Sciences/Medical Devices & Instruments