THE DSP SOLUTION SPECTRUM FOR MEDICAL IMAGING
APPLICATIONS USING FPGA
SAVITA1st YearM.tech,
DSPCET DIGITAL SIGNAL PROCESSING
INTRODUCTION
• The combined requirements of fast time to market and high performance processing are driving the use of FPGAs in video, image and signal processing applications.
• Computerized Axial Tomography (CAT scanner), which captures a series of cross-sectional views of body projections that can be intelligently assembled into three-dimensional images.
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FIELD PROGRAMMABLE GATE
ARRAYS (FPGA) Providing higher performance than GPP and DSP ASSPs alone. The additional spectrum of FPGA solutions include:• Using FPGAs to distribute and collect data to and from a
matrix of DSP ASSPs• Using the FPGA as a coprocessor or custom peripheral to a
DSP• Using embedded soft CPUs and the parallel DSP processing structures within the FPGA to eliminate the DSP ASSPs Figure 1
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FPGA…
FPGA…
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FPGA…DSP MATRIXReplace the DSP with a higher frequency modelRewrite portions of the software into pipelined assembly codeCreates a DSP matrix where multiple DSPs are arrayed together to deliver parallel DSP processing.The core difficulty with using DSPs for all pixel processing relates to cost.Although multiple DSPs can be utilized to obtain higher parallel processing, the costs rise very quickly as the process is implemented.
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FPGA…
FPGA CO-PROCESSING SOLUTIONThis approach leverages the existing code base of a single DSP software image with the massively parallel processor resources embedded within the FPGA.The DSP continues to execute the majority of the code including all complex control plane processing, allowing the FPGA to act as a custom peripheral or coprocessor to accelerate any process intensive code within the imaging algorithm
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FPGA…
Figure 2
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FPGA…
• Custom Processor (CusP) is software programmed processor consisting of building block functions with reconfigurable interconnections between the blocks
• Custom instruction using hardware extensions of the soft CPU instruction set, such as a floating-point instruction implemented in hardware• Custom peripheralcan be used with internal or external CPU
Table 1
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CT SCANNER
• First developed in the early 1970s, steady technological improvements have made this type of scanner an invaluable radiologic diagnostic device.
• It is a medical imaging tool that provides clear pictures of the internal structures of the body. Utilizing a beam of x rays and a radiation detector, it supplies data to a computer, which then constructs a three-dimensional image.
• The images produced by conventional film x rays are often fuzzy because many of the internal structures are superimposed on each other. Tomography was developed to reduce this fuzziness and allow for the imaging of specific areas in the body.
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CT SCANNER
•Figure 1. CT Imaging Data Flow
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CT SCANNER
• Figure 2. Computed Tomography (CT) Back Projection
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CT SCANNER
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HEART MITRAL VALVE: 2D IMAGE
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HEART MITRAL VALVE WITH COLOR FLOW
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DIFFERENCE BETWEEN DSP AND FPGA The max clock rate of DSP is 1GHZ and FPGA is 370MHZ
Max instructions per clock in DSP is 4 to 8 and in FPGA is 100s to 1000s
The ease of programming in DSP is C, C++, Software flow and in FPGA is HDL, Hardware flow
I/O Flexibility in DSP is limited and in FPGA is much flexible Memory management in DSP is Built-In and FPGA it is
manual Power consumption in DSP is low and in FPGA is high
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APPLICATIONS
Digital signal processing Medical imaging Computer vision Speech recognition Computer hardware emultion and a growing range of other
areas
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ADVANTAGES FPGAs offer additional functionality, faster execution speeds,
and lower power requirements. A growing advantage of an FPGA-based system is that we
upgrade features by sending software and hardware improvements.
The ability to upgrade an expensive piece of medical imaging equipment by a simple file transfer means a longer time-in-market for instrument manufacturers and cost savings for healthcare establishments needing to replace equipment.
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CONCLUSION
FPGA vendors are directing major efforts to address DSP applications for medical imaging. Consequently, FPGA solutions will increasingly provide the processing power new medical imaging applications require to handle challenges such as ultra-high signal processing performance, very-high memory bandwidth, and increased interconnectivity between processing elements.
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THANK YOU
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