OptoSonics' proprietary detector array geometry is the heart of our photoacoustic computed tomography (PAT) and integrated backscatter ultrasound (IBUS) 3D imaging technologies. Select one of the short presentations below to learn the basics of PAT and IBUS.
Our detector arrays contain between 128 and 512 individual ultrasonic transducer elements laid out in spiral patterns on a hemispherical surface. The hemispherical bowl is watertight with a 100 mm radius of curvature. Each transducer has a diameter of 3 mm and operates at different center frequencies, depending on the imaging modality.
The detector bowl is mounted in a rigid frame along with a stepper motor in a configuration that allows full 360 degree rotation of the array.
A pulsed excitation source (near-infrared laser light for PAT or an acoustic signal for IBUS) propagates from an aperture at the bottom of the bowl or through one or more transponders to the sample. The sample is suspended in the bowl and acoustically coupled to the transducers through an appropriate medium. A customized data acquisition system allows capturing of the generated or reflected ultrasound signals at each detector.
By rotating the bowl to multiple angular positions, we can effectively increase the density of K-space sampling of the projections through the sample to be imaged. The entire detector array can be rotated through 360 degrees in as fast as 3 seconds, recording enough data to compute 30 separate 3D volumes in that time period. A filtered backprojection algorithm then reconstructs the 3D volumes.
