Systems and methods of managing erroneous signals in marker-based devices
In part, the disclosure relates to a method of detecting a marker in a subject in the presence of one or more interfering signals. The method may include detecting a first marker signal; detecting a first interfering signal; comparing one or more characteristics or a metric correlated therewith of the first interfering signal with an interference signal threshold; and generating user feedback based on the comparison and/or movement of a detection probe.
1 . A method of localizing a marker in the presence of one or more interfering signals using a hand-held probe in communication with a non-imaging marker localization system, the method comprising:
detecting a marker signal using the hand-held probe;
measuring, using the hand-held probe, a set of parameters of the marker signal, the parameters varying over time and with the position of the hand-held probe relative to the marker;
determining a dynamic range of values of a variable of the marker signal, wherein the variable is selected from the set of parameters of the marker signal, wherein the dynamic range of values vary according to measured values of the set of parameters of the marker signal;
detecting an interfering signal using the hand-held probe by measuring the value of the variable of the marker signal, and
comparing the measured value of the variable of the marker signal with the dynamic range of values of the variable;
determining the marker signal to be an erroneous signal when the measured value of the variable falls outside the dynamic range of values; and
generating user feedback indicating the erroneous signal.
2 . The method of claim 1 , wherein the user feedback comprises removing one or more on screen graphical user interface depictions of a portion of the hand-held probe or target marker area when the measured value of the variable of the marker signal falls outside the range of values of the variable.
3 . The method of claim 1 , wherein the user feedback comprises a change or cessation of auditory feedback presented to user when the measured value of the variable of the marker signal falls outside the range of values of the variable.
4 . The method of claim 1 , further comprising repeating the comparing step until the measured value of the variable of the marker signal falls within the range of values of the variable.
5 . The method of claim 4 , further comprising resuming marker detection without monitoring for an interference signal.
6 . The method of claim 4 , wherein the detecting of an interfering signal is performed relative to a zone or region within which the interfering signal and the marker signal overlap.
7 . The method of claim 6 , wherein the hand-held probe is a magnetic susceptometry detection probe.
8 . The method of claim 1 , further comprising selecting a new variable from the set of parameters of the marker signal when the measured value of the variable falls outside the range of values of the variable.
9 . The method of claim 1 , wherein the set of parameters of the marker signal comprises two or more parameters selected from a magnitude of the marker signal, a phase of the marker signal, ratios of the magnitude and/or phase of the marker signal at two or more different frequencies, a spatial arrangement of the signal around the hand-held probe, relative magnitudes of the signal at different regions around the probe, an orientation of the signal at different regions around the probe, a quality of modulation of the signal, ratios of any of the foregoing, and statistical metrics and/or variables or relationships correlated with any of the foregoing.
10 . The method of claim 1 , wherein the—variable is a signal-to-noise ratio (SNR) and the dynamic range of values varies with SNR, wherein the SNR is determined using a strength of marker signal relative to interference.
11 . The method of claim 1 further comprising in response to a selected variable not being within a desired range, selecting a new dynamic variable that is not subject to signal interference as probe changes position.
12 . The method of claim 1 further comprising distinguishing between a first zone and a second zone to inform user actions relative to a user interface, wherein a first level of overlap between a detection signal and interference signal in the first zone differs from a second level of overlap between a detection signal and interference signal in the second zone.
13 . The method of claim 1 further comprising displaying a standby mode display when an interference signal is detected, the standby mode display comprising a probe representation and a marker representation, wherein the erroneous signal is an interference signal.
14 . A method of localizing a marker in the presence of one or more interfering signals using a hand-held probe in communication with a non-imaging marker localization system, the method comprising:
detecting a marker signal using the hand-held probe;
measuring, using the hand-held probe, a set of parameters of the marker signal, wherein the set of parameters of the marker signal vary over time and with the position of the hand-held probe relative to the marker;
selecting a variable of the marker signal, wherein the variable is selected from the set of parameters of the marker signal;
determining a dynamic range of values of the variable of the marker signal, wherein the dynamic range of values vary according to measured values of the set of parameters of the marker signal, wherein each parameter of the marker signal of the set of parameters are measurable by the hand-held probe and vary over time and with a position of the hand-held probe relative to the marker;
detecting an interfering signal using the hand-held probe by measuring the value of the variable of the marker signal;
comparing the measured value of the variable of the marker signal with the dynamic range of values of the variable; and
determining the selected variable is not within a desired range and, in response thereto, selecting a new dynamic variable that is not subject to signal interference when localizing the marker.
15 . The method of claim 14 wherein determining that the selected variable is not within a desired range is performed by comparing the measured value of the variable of the marker signal with the dynamic range of values of the variable.
16 . The method of claim 14 further comprising distinguishing between a first zone and a second zone to inform user actions relative to a user interface, wherein a first level of overlap between a detection signal and interference signal in the first zone differs from a second level of overlap between a detection signal and interference signal in the second zone.
17 . The method of claim 14 further comprising displaying a standby mode display when an interference signal is detected, the standby mode display comprising a probe representation and a marker representation.