Non invasive identification of intestinal ischemia from measurement of basic electrical rhythm of intestinal smooth muscle electrical activity using a magnetometer
First Claim
1. A non-invasive method of diagnosing intestinal ischemia from a magnetic field produced by smooth muscle electrical activity in an intestine in vivo within an abdomen, said method comprising the steps of:
- measuring the magnetic field produced by said smooth muscle electrical activity in said intestine at at least one location external to said abdomen;
determining a measured value of local Basic Electrical Rhythm (BER) frequency from said magnetic field at said at least one location external to said abdomen;
establishing a nominal value for said local BER frequency at said at least one location; and
identifying intestinal ischemia at said at least one location when said measured value of local BER frequency at said at least one location differs from said nominal value for said local BER frequency by a predetermined margin and is accompanied by an interval of arrhythmia.
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Abstract
Intestinal ischemia is diagnosed non-invasively by scanning the abdomen externally with a SQUID magnetometer which measures the magnetic field produced by smooth muscle electrical activity. These measurements are processed to determine the basic electrical rhythm (BER) frequency at various locations along the intestine. A nominal value for the BER frequency is established at each location, and if the measured value falls below the associated nominal value by more than a predetermined margin, ischemia at that location is indicated. Ischemia is further indicated by an interval of arrhythmia in which the BER frequency increases to a range of about 24-180 cpm or at least about twice the nominal value. The BER frequency values are presented on a graphic display which provides an indication of the nominal value at an affected location from the gradient of the measured values at adjacent normal locations. Also, a gradual reduction in the local BER frequency at a particular location is an indication of progressive ischemia, while an absence of BER activity in a section of intestine indicates necrosis.
34 Citations
24 Claims
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1. A non-invasive method of diagnosing intestinal ischemia from a magnetic field produced by smooth muscle electrical activity in an intestine in vivo within an abdomen, said method comprising the steps of:
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measuring the magnetic field produced by said smooth muscle electrical activity in said intestine at at least one location external to said abdomen; determining a measured value of local Basic Electrical Rhythm (BER) frequency from said magnetic field at said at least one location external to said abdomen; establishing a nominal value for said local BER frequency at said at least one location; and identifying intestinal ischemia at said at least one location when said measured value of local BER frequency at said at least one location differs from said nominal value for said local BER frequency by a predetermined margin and is accompanied by an interval of arrhythmia. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. Apparatus for analyzing a magnetic field produced by smooth muscle electrical activity in an intestine in vivo within an abdomen for use in non-invasive diagnosis of intestinal ischemia, said apparatus comprising:
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magnetometer means producing detected values of said magnetic field at at least one location across said abdomen; processing means generating from said detected values of said magnetic field measured values of local basic electrical rhythm (BER) frequency of said smooth muscle electrical activity at said at least one location including values associated with arrhythmia; and means presenting a representation of said measured values of local BER frequency including said values associated with arrhythmia. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
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22. A non-invasive method of diagnosing intestinal ischemia from a magnetic field produced by smooth muscle electrical activity in an intestine in vivo within an abdomen, said method comprising the steps of:
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measuring the magnetic field produced by said smooth muscle electrical activity in said intestine at at least one location external to said abdomen; determining a measured value of local Basic Electrical Rhythm (BER) frequency from said magnetic field at said at least one location external to said abdomen; and identifying intestinal ischemia at said at least one location when said measured value of said local BER frequency at said at least one location exhibits an interval of arrhythmia. - View Dependent Claims (23, 24)
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Specification