MEDICAL SURGICAL SPONGE AND INSTRUMENT DETECTION SYSTEM AND METHOD
First Claim
1. A magnet detector for locating magnetically tagged items in a surgical patient, comprising:
- a three-dimensional (x,y,z) sensor, moveable throughout a magnetic field at the patient, a first output of the sensor represents a first-sensed magnetic field strength vectors for three dimensions at a first spatial location of the sensor and a second output of the sensor represents a second-sensed magnetic field strength vectors for three dimensions at a second spatial location of the sensor;
a processor communicatively connected to the sensor, for receiving the first output and the second output and calculating a value from the first output and the second output representative, respectively, of an ambient scalar (Mv(x)ambient) of the first-sensed magnetic field strength vectors and the second-sensed magnetic field strength vectors;
a storage for the value;
a magnetic field anomaly subsequently induced to the magnetic field at the first spatial location and the second spatial location, the sensor, thereafter moveable throughout the magnetic field of the patient, a third output of the sensor represents a third-sensed magnetic field strength vectors and a fourth-sensed magnetic field strength vectors for three dimensions at the first spatial location and the second spatial location, respectively, of the sensor;
wherein the processor receives the third output and the fourth output of the sensor, calculates a different value from the third output and the fourth output, the different value representative, respectively, of a different anomalous scalar (Mv(x)anomaly) of the third-sensed magnetic field strength vectors and the fourth-sensed magnetic field strength vectors.
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Accused Products
Abstract
A magnetic detector locates magnetically tagged items, such as surgical sponges or instruments, introduced to and remaining in the body cavity of a surgical patient. The magnetic detector is a wand or probe that is manually handleable, and spatially manipulable and moveable, by an operator, such as a medical professional. The detector is moved about at a spatial location of an ambient magnetic field at the patient and operating table. A characteristic of the ambient magnetic field at the spatial location is saved by the detector. The detector is subsequently moved about at the same spatial location. If any magnetically tagged item is present in the vicinity of the detector during this subsequent movement at the spatial location, an anomalous magnetic effect is detected by comparison of the prior detection reading absent the tagged item to the detection reading in presence of the tagged item in the patient. The anomalous magnetic effect, and thus the tagged item, is locatable spatially in the patient, by three-dimensional sensor(s), arrays of sensors, and pluralities of arrays of sensors of the detector. The different detection readings with and without presence of the anomalous magnetic effect caused by presence of the tagged item in the patient are calculable as scalar, vector array, and/or gradient array determinations, according to the particular number and configuration of sensors in the detector.
76 Citations
27 Claims
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1. A magnet detector for locating magnetically tagged items in a surgical patient, comprising:
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a three-dimensional (x,y,z) sensor, moveable throughout a magnetic field at the patient, a first output of the sensor represents a first-sensed magnetic field strength vectors for three dimensions at a first spatial location of the sensor and a second output of the sensor represents a second-sensed magnetic field strength vectors for three dimensions at a second spatial location of the sensor; a processor communicatively connected to the sensor, for receiving the first output and the second output and calculating a value from the first output and the second output representative, respectively, of an ambient scalar (Mv(x)ambient) of the first-sensed magnetic field strength vectors and the second-sensed magnetic field strength vectors; a storage for the value; a magnetic field anomaly subsequently induced to the magnetic field at the first spatial location and the second spatial location, the sensor, thereafter moveable throughout the magnetic field of the patient, a third output of the sensor represents a third-sensed magnetic field strength vectors and a fourth-sensed magnetic field strength vectors for three dimensions at the first spatial location and the second spatial location, respectively, of the sensor; wherein the processor receives the third output and the fourth output of the sensor, calculates a different value from the third output and the fourth output, the different value representative, respectively, of a different anomalous scalar (Mv(x)anomaly) of the third-sensed magnetic field strength vectors and the fourth-sensed magnetic field strength vectors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of detecting presence of a magnetic tag of an item in a surgical patient, comprising the steps of:
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first sensing a one-dimensional characteristic of a three-dimensional magnetic field at the patient at a spatial location; first processing the one-dimensional characteristic from the step of first sensing, to obtain an ambient magnetic field scalar (Mv(x)ambient) for the spatial location; second sensing the one-dimensional characteristic of the three-dimensional magnetic field at the patient at the spatial location, the magnetic tag present at about the spatial location; second processing the one-dimensional characteristic of the step of second sensing, to obtain an anomolous magnetic field scalar (Mv(x)aanomaly) for the spatial location; calculating a difference value (Δ
=|(Mv(x)ambient)−
(Mv(x)anomaly)|) in the ambient magnetic field scalar and the anomalous magnetic field scalar for the spatial location; andsignaling if the difference value exceeds a threshold level, indicative of presence of the magnetic tag of the device at about the spatial location. - View Dependent Claims (14, 15)
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16. A method of detecting presence of a magnetic tag of an item in a surgical patient, comprising the steps of:
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first sensing a two-dimensional characteristic of a three-dimensional magnetic field at the patient at a spatial location; first processing the two-dimensional characteristic from the step of first sensing, to obtain an ambient magnetic field strength array (Mv(x,y)ambient) for the spatial location; second sensing the two-dimensional characteristic of the three-dimensional magnetic field at the patient at the spatial location, the magnetic tag present at about the spatial location; second processing the two-dimensional characteristic of the step of second sensing, to obtain an anomalous magnetic field strength array (Mv(x,y)anomaly) for the spatial location; calculating a difference array value (Δ
=|(Mv(x,y)ambient)−
(Mv(x,y)anomaly)|) in the ambient magnetic field strength array and the anomalous magnetic field strength array for the spatial location; andsignaling if the difference array value exceeds a threshold level, indicative of presence of the magnetic tag of the device at about the spatial location. - View Dependent Claims (17, 18)
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19. A method of detecting presence of a magnetic tag of an item in a surgical patient, comprising the steps of:
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first sensing a three-dimensional characteristic of a three-dimensional magnetic field at the patient at a spatial location; first processing the three-dimensional characteristic from the step of first sensing, to obtain an ambient magnetic field gradient array (Mv(x,y,z)ambient) for the spatial location; second sensing the three-dimensional characteristic of the three-dimensional magnetic field at the patient at the spatial location, the magnetic tag present at about the spatial location; second processing the three-dimensional characteristic of the step of second sensing, to obtain an anomalous magnetic field gradient array (Mv(x,y,z)anomaly) for the spatial location; calculating a difference gradient array value (Δ
=|(Mv(x,y,z)ambient)−
(Mv(x,y,z)anomaly)|) in the ambient magnetic field gradient array and the anomalous magnetic field gradient array for the spatial location; andsignaling if the difference gradient array value exceeds a threshold level, indicative of presence of the magnetic tag of the device at about the spatial location. - View Dependent Claims (20, 21)
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22. A method of detecting presence of a magnetic tag of an item in a surgical patient, comprising the steps of:
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first moving a detector at a spatial location of an ambient magnetic field at the patient; saving a characteristic of the ambient magnetic field at the spatial location; second moving the detector in a magnetic anomaly to the ambient magnetic field, induced to the ambient magnetic field at the spatial location the patient; and determining the presence of the magnetic anomaly at about the spatial location by the detector. - View Dependent Claims (23, 24)
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25. A magnetic detector for locating a magnetically tagged item in a surgical patient, the item is contained within a patient body cavity located a distance along a one-dimensional axis in space from the magnetic detector, comprising:
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a first sensor array in a first plane in space centered at and perpendicular to the one-dimensional;
axisa second sensor array positioned in a second plane in space, parallel to the first plane but not in the first plane, centered at and perpendicular to the one-dimensional axis; a third sensor array positioned in a third plane in space, parallel to the first plane and second plane but not in either the first plane or the second plane, centered at and perpendicular to the one-dimensional axis; wherein the magnetic detector has a three-dimensional volume of interest for detections, the three-dimensional volume extending in space along the one-dimensional axis generally into the body cavity in space, the three-dimensional volume being defined in space extending along the axis as centrum of the three-dimensional volume in direction of the axis, having an outer extent being defined as the greatest extension point in space from the axis that is outwardly extending for the first array in the first plane, the second array in the second plane, and the third array in the third plane, whichever is greatest outwardly extending in respective planes; wherein the magnetic detector has a sensor volume of interest for detections, the sensor volume extending in space three-dimensionally along the one-dimensional axis within the three-dimensional volume, the sensor volume extending in direction of the axis having centrum along the axis, having an outer extent of the sensor volume being defined by a uniquely detectable region central to the three-dimensional volume for, collectively, the first array, the second array and the third array; wherein the magnetic detector is capable of cancelling out any relevant ambient magnetic effects, automatically, because of the uniquely detectable region being formed by at least one, but not all, of the sensors of, collectively, the first array, second array and the third array, and the sensors not included within the uniquely detectable region being sufficient for magnetic vector gradient determination via comparison with sensors of the uniquely detectable region; wherein the magnetic detector, when positioned at a location from the patient, finds the item at a vicinity of the patient body cavity centered at the axis extending into the patient, because of difference of magnetic vector gradient then-determined by the magnetic detector as being in excess of a threshold value, the threshold value being related to magnetic vector gradient for the same location as if without presence.
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26. A detector for locating a magnetized tag in a human body, the magnetized tag is positioned in a direction (A) from the detector, comprising:
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a first array of planarly arranged individual sensor elements having a first centrum located in the direction (A) with respect to the tag, of a first plane; a second array of planarly arranged individual sensor elements having a second centrum located in the direction (A) with respect to the tag, of a second plane that is not the first plane; wherein the second array is positioned, in space, parallel to the first array; wherein an imaginary three-dimensional volume, extending longitudinally perpendicular to the first array and the second array and defined by extents of the first array and the second array in respective first plane and second plane, is an area of interest for detections by the detector; wherein the detector effectively discounts, automatically, any relevant ambient magnetic effects substantially within the area of interest; wherein the detector locates the tag in the human body when the tag is within the area of interest the tag, based on a difference value of magnetic vector gradient detected in presence of the tag versus magnetic vector gradient detected without presence of the tag, at about the same location for the area of interest, respectively. - View Dependent Claims (27)
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Specification