MRI noise detector and suppressor
AssigneeNetcom, Inc.
InventorWarren Guthrie
Life of this patent
Estimating the term…
Abstract
An improved transient interference detector and suppressor for an MRI system detects the presence of transient interference in an MRI signal by detecting the envelope of the MRI signal and comparing the rate of change of the envelope to a reference signal. When the rate of change of the envelope exceeds the reference signal, a transient interference detection is made and appropriate action may be taken. When the rate of change of the envelope is less than the reference signal, no transient interference detection is made. The reference signal is set at a level slightly above a level corresponding to the average thermal noise in order to substantially prevent the minor, random fluctuations in the thermal noise from falsely triggering the detection of a transient interference event.
Claims36
A method of detecting transient interference in an MRI signal received from an MRI receiving antenna comprising:
- detecting a parameter of the MRI signal that varies as the envelope of the MRI signal varies and filtering out low frequency components of said MRI signal to thereby produce a filtered parameter signal;
- comparing said filtered parameter signal to a reference signal;
- and
- determining that said MRI signal likely includes interference if said filtered parameter signal exceeds said reference signal.
A method for detecting transient interference in an MRI signal received from an MRI receiving antenna comprising:
- detecting an envelope of said MRI signal and filtering out low frequency components of said MRI signal to thereby produce a filtered envelope signal;
- comparing said filtered envelope signal to a reference signal;
- and
- determining that said MRI signal likely includes interference if said filtered envelope signal exceeds said reference signal.
An interference detection system for detecting interference in an MRI signal received from an MRI receiving antenna comprising:
- a filter designed to remove low frequencies within said MRI signal;
- an envelope detector that detects the envelope of said MRI signal, said filter and said envelope detector producing in combination a filtered envelope signal;
- and
- a comparator that compares said filtered envelope signal to a reference signal and outputs an interference signal if said filtered envelope signal exceeds said reference signal.
A interference detection system for detecting interference in an MRI signal received from an MRI receiving antenna comprising:
- a filter designed to remove low frequencies within said MRI signal;
- an detector that detects a parameter that varies as the envelope of said MRI varies, said filter and said detector producing in combination a filtered parameter signal;
- and
- a comparator that compares said filtered parameter signal to a reference signal and outputs an interference signal if said filtered parameter signal exceeds said reference signal.
An interference detection system for detecting interference in an MRI signal received from an MRI receiving antenna comprising:
- a detector log video amplifier;
- a high pass filter;
- and
- a comparator that compares the MRI signal after the MRI signal has passed through said detector log video amplifier and said high pass filter to a reference voltage, said comparator outputting an interference signal if said reference voltage is exceeded.
Dependencies are inferred from the claim text.