Electricity: measuring and testing – Particle precession resonance – Spectrometer components
Patent
1995-11-28
1998-04-14
Arana, Louis M.
Electricity: measuring and testing
Particle precession resonance
Spectrometer components
324307, G01V 300
Patent
active
057396914
ABSTRACT:
A digital lowpass filter design for filtering nuclear magnetic resonance (NMR) signals in a magnetic resonance imaging (MRI) system supports multiple frequencies and is highly configurable without sacrificing speed and performance. The first FIR filter stage of a synchronized multirate digital filter is selected from a database of filter coefficient/parameter sets which are loaded at start time and used in place. Second (and later) FIR filter stages are fixed in the example. A large number of different filter frequencies can be selected rapidly without changing the parameterized filter program reducing the amount of time to start up the MRI system and allowing "on-the-fly" filter changes in real-time between echoes and/or A/D samples. For example, filter preselection by the host can be performed in less than 100 .mu.s, and, one of several lowpass filters can be selected by the sequencer "on-the-fly" with a latency of less than 10 .mu.s.
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Arana Louis M.
The Regents of the University of California
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