Digital Detection Techniques for Dynamic Optical Tomographic Imaging

In this paper we present a novel application of digital detection and data-acquisition techniques to a prototype dynamic optical tomography system. The core component is a digital signal processor (DSP) that is responsible for collecting and processing the digitized data set. Utilizing the processing power of the DSP, real-time data rates for this 16-source, 32-detector system, can be achieved at rates as high as 140Hz per tomographic frame. Many of the synchronously-timed processes are controlled by a complex programmable logic device (CPLD) that is used in conjunction with the DSP to orchestrate data flow. The operation of the instrument is managed through a comprehensive graphical user interface, which was designed using the LabVIEW software package. Performance analysis demonstrates very low system noise (~.60pW RMS noise equivalent power) and excellent signal precision (<0.1%) for most practical cases. First experiments on tissue phantoms show that dynamic behavior can be accurately captured using this system.