Srikant Vaithilingam

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Photoacoustic imaging of living subjects offers higher spatial resolution and allows deeper tissues to be imaged compared with most optical imaging techniques. As many diseases do not exhibit a natural photoacoustic contrast, especially in their early stages, it is necessary to administer a photoacoustic contrast agent. A number of contrast agents for(More)
Photoacoustic imaging is an emerging modality that overcomes to a great extent the resolution and depth limitations of optical imaging while maintaining relatively high-contrast. However, since many diseases will not manifest an endogenous photoacoustic contrast, it is essential to develop exogenous photoacoustic contrast agents that can target diseased(More)
In this paper, we describe using a 2-D array of capacitive micromachined ultrasonic transducers (CMUTs) to perform 3-D photoacoustic and acoustic imaging. A tunable optical parametric oscillator laser system that generates nanosecond laser pulses was used to induce the photoacoustic signals. To demonstrate the feasibility of the system, 2 different phantoms(More)
A large area reconfigurable imaging array for research purposes is being developed with co-integrated cMUTs and control electronics. The goal is a 2.5cm 2D tileable module with >16,000 transducer sub-elements spaced at a pitch of 185um in X and Y dimensions. As a prototype demonstration of some of the goals of this effort, a multi-row linear array using(More)
In this paper, we demonstrate 3-D photoacoustic imaging (PAI) of light absorbing objects embedded as deep as 5 cm inside strong optically scattering phantoms using a miniaturized (4 mm × 4 mm × 500 μm), 2-D capacitive micromachined ultrasonic transducer (CMUT) array of 16 × 16 elements with a center frequency of 5.5 MHz. Two-dimensional tomographic images(More)
In this paper, we investigate using a large aperture (64 x 64 element array) to perform photoacoustic and acoustic imaging by mechanically scanning a smaller array (16 x 16 elements) of capacitive micromachined ultrasonic transducers (CMUTs). We show results from the imaging of: 1) A fishing-line phantom. 2) Tubes embedded in chicken breast tissue(More)
In this work, we demonstrate 3-D photoacoustic imaging of optically absorbing targets embedded as deep as 5 cm inside a highly scattering background medium using a 2-D capacitive micromachined ultrasonic transducer (CMUT) array with a center frequency of 5.5 MHz. 3-D volumetric images and 2-D maximum intensity projection images are presented to show the(More)
We introduce a versatile fabrication process for direct wafer-bonded CMUTs. The objective is a flexible fabrication platform for single element transducers, 1D and 2D arrays, and reconfigurable arrays. The main process features are: A low number of litho masks (five for a fully populated 2D array); a simple fabrication sequence on standard MEMS tools(More)
A scanning acoustic and photoacoustic microscope is demonstrated. The laser illumination and ultrasound detection in the system are co-axial. Pulsed light from a tunable optical parametric oscillator (OPO) laser is delivered to the scan tank via optical fiber. Multiple acoustic transducers with center frequencies varying from 5 MHz to 25 MHz are utilized.(More)
Capacitive micromachined ultrasonic transducers (CMUTs) overcome many limitations of existing ultrasound transducer technologies enabling new applications of ultrasound, especially for medical imaging and treatment. Some of the most important of these advancements are the ability to fabricate transducer arrays with two dimensional geometries and high(More)