Apparatus and method for characterizing movement of a mass within a defined space
First Claim
1. Apparatus for characterizing movement of a mass within a defined space, the apparatus comprising:
- a. a plurality of electrodes proximate to the space, the electrodes having fixed positions relative to each other;
b. an AC source;
c. means for momentarily connecting at least a first electrode to the AC source a plurality of times so as to produce a plurality of electric fields;
d. means for measuring current into the unconnected electrodes each time the field-producing electrode is connected to the AC source, thereby producing a plurality of measurements through the unconnected electrodes, at least some of the electrodes being switchably connectable to the AC source or to the current-measuring means to thereby serve as field-producing electrodes or as measurement electrodes; and
e. means for characterizing movement of the mass within the space based on the plurality of measurements.
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Accused Products
Abstract
Apparatus and methods for resolving presence, orientation and activity of a person within a defined space utilizes at least one electrode proximate to the space to be observed. An AC signal is applied to the electrode, and the current measured from that electrode and also to any other electrodes included in the system, and which are effectively connected to the ground return of the AC-coupled electrode. A person (or object) to be sensed intercepts a part of the electric field extending beween the AC-coupled "sending" electrode and the other "receiving" electrodes, the amount of the field intercepted depending on the size and orientation of the sensed person, whether or not the person provides a grounding path, and the geometry of the distributed electrodes. Given the nonlinear spatial dependence of the field, multiple electrodes can reliably distinguish among a set of expected cases. The invention can be configured to detect not only static positions and orientations, but also motion through a defined space. This is accomplished by taking sequential measurements at different times and utilizing the time variation in signal magnitudes as well as the absolute magnitudes themselves.
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Citations
8 Claims
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1. Apparatus for characterizing movement of a mass within a defined space, the apparatus comprising:
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a. a plurality of electrodes proximate to the space, the electrodes having fixed positions relative to each other; b. an AC source; c. means for momentarily connecting at least a first electrode to the AC source a plurality of times so as to produce a plurality of electric fields; d. means for measuring current into the unconnected electrodes each time the field-producing electrode is connected to the AC source, thereby producing a plurality of measurements through the unconnected electrodes, at least some of the electrodes being switchably connectable to the AC source or to the current-measuring means to thereby serve as field-producing electrodes or as measurement electrodes; and e. means for characterizing movement of the mass within the space based on the plurality of measurements. - View Dependent Claims (2, 3, 4)
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5. A method of characterizing movement of a mass within a defined space, the method comprising the steps of:
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a. providing at least two electrodes proximate to the space; b. sequentially sending an AC signal out each of the at least two electrodes at fixed intervals so as to produce a plurality of electric fields; c. measuring current out of the electrode as the AC is sent; and d. characterizing movement of the mass within the space based on the measurements by (i) providing a pattern of measurement clusters each associated with a movement, (ii) comparing the measurements against the pattern, and (iii) based on the comparison, characterizing the movement. - View Dependent Claims (7)
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6. A method of characterizing movement of a mass within a defined space, the method comprising the steps of:
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a. providing at least two electrodes proximate to the space, the electrodes having fixed positions relative to each other; b. momentarily sending an AC signal out a first electrode a plurality of times so as to produce a plurality of electric fields; c. measuring current into at least one unconnected electrode each time the signal is sent out the first electrode, thereby producing a plurality of measurements; and d. characterizing movement of the mass within the space based on the plurality of measurements by (i) providing a pattern of measurement clusters each associated with a movement, (ii) comparing the measurements against the pattern to thereby characterize movement, and (iii) based on the comparison, characterizing the movement. - View Dependent Claims (8)
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Specification