In vivo optical measurements of hematocrit
First Claim
1. An apparatus for measuring hematocrit of a subject'"'"'s blood, the apparatus comprising:
- a) a optical source capable of illuminating subcutaneous blood vessels;
b) an optical element capable of receiving at least a portion of an optical beam reflected from said vessels;
c) a detector for receiving input from said optical element; and
d) a processor for determining hematocrit based upon input received from said optical element.
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Accused Products
Abstract
An apparatus for measuring hematocrit of a subject'"'"'s blood includes an optical source that generates an optical beam that illuminates subcutaneous vessels under a subject'"'"'s skin. An optical element is positioned to receive a near field portion of the optical beam that is reflected from the subcutaneous vessels under the subject'"'"'s skin. A scanning mechanism positions the optical element relative to the subcutaneous vessels under the subject'"'"'s skin over a plurality of relative distances. An optical detector generates a plurality of electrical signals in response to detecting the near field portion of the optical beam that is reflected from the subcutaneous vessels under the subject'"'"'s skin at the plurality of relative distances between the optical element and the subcutaneous vessels. A processor determines a value of hematocrit in the subcutaneous vessels illuminated by the optical beam from the plurality of electrical signals generated by the optical detector.
20 Citations
32 Claims
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1. An apparatus for measuring hematocrit of a subject'"'"'s blood, the apparatus comprising:
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a) a optical source capable of illuminating subcutaneous blood vessels;
b) an optical element capable of receiving at least a portion of an optical beam reflected from said vessels;
c) a detector for receiving input from said optical element; and
d) a processor for determining hematocrit based upon input received from said optical element. - View Dependent Claims (2, 3)
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4. An apparatus for measuring hematocrit of a subject'"'"'s blood, the apparatus comprising:
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a) an optical source that generates an optical beam, the optical source being positioned to illuminate subcutaneous vessels under a subject'"'"'s skin with the optical beam;
b) an optical element having an input that is positioned to receive a near field portion of the optical beam that is reflected from the subcutaneous vessels under the subject'"'"'s skin;
c) a scanning mechanism that positions the optical element relative to the subcutaneous vessels under the subject'"'"'s skin at a plurality of relative distances;
d) an optical detector having an input that is optically coupled to an output of the optical element, the optical detector generating a plurality of electrical signals at an output in response to detecting the near field portion of the optical beam that is reflected from the subcutaneous vessels under the subject'"'"'s skin at the plurality of relative distances between the optical element and the subcutaneous vessels; and
e) a processor having an input that is electrically connected to the output of the detector, the processor receiving the plurality of signals generated by the optical detector and determining a value of hematocrit in the subcutaneous vessels illuminated by the optical beam from the plurality of electrical signals. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An apparatus for measuring hematocrit of a subject'"'"'s blood, the apparatus comprising:
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a) an optical source that generates an optical beam, the optical source being positioned to illuminate subcutaneous vessels under a subject'"'"'s skin with the optical beam;
b) a plurality of optical detectors, each of the plurality of optical detectors having an input that is positioned at one of a plurality of unique relative distance to the subcutaneous vessels under a subject'"'"'s skin to detect a near field portion of the optical beam that is reflected the unique relative distance, each of the plurality of optical detectors generating an electrical signal at an output in response to the detected near field portion of the optical beam; and
c) a processor having inputs that are electrically connected to the outputs of the plurality of optical detectors, the processor receiving signals from the outputs of the plurality of optical detectors and determining a value of hematocrit in the subcutaneous vessels illuminated by the optical beam from the plurality of electrical signals generated by the plurality of optical detectors. - View Dependent Claims (15, 16, 17)
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18. A method of measuring hematocrit of a subject'"'"'s blood, the method comprising:
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a) illuminating subcutaneous vessels under a subject'"'"'s skin with an optical beam;
b) detecting a plurality of near field intensities of a portion of the optical beam that is reflected from the subcutaneous vessels under the subject'"'"'s skin and generating a plurality of electrical signals in response to the detected near field intensities, each of the plurality of near field intensities being detected at a unique distance relative to the subcutaneous vessels under a subject'"'"'s skin; and
c) determining a value of hematocrit of blood in the subcutaneous vessels illuminated by the optical beam from the plurality of electrical signals. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A method of measuring hematocrit of a subject'"'"'s blood, the method comprising:
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a) illuminating subcutaneous vessels under a subject'"'"'s skin with an optical beam;
b) detecting a first near field intensity of a portion of an optical beam that is reflected a first distance from the subcutaneous vessels under the subject'"'"'s skin and generating a first electrical signal in response to the first detected near field intensities;
c) detecting a second near field intensity of a portion of an optical beam that is reflected a second distance from the subcutaneous vessels under the subject'"'"'s skin and generating a second electrical signal in response to the second detected near field intensities;
d) determining a ratio of the first and the second electrical signals; and
e) determining a value of hematocrit in the subcutaneous vessels illuminated by the optical beam from the ratio of the first and the second electrical signals. - View Dependent Claims (29)
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30. A method of measuring hematocrit of a subject'"'"'s blood, the method comprising:
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a) illuminating subcutaneous vessels under a subject'"'"'s skin with an optical beam;
b) detecting at least one near field intensity of a portion of an optical beam that is reflected from the subcutaneous vessels under the subject'"'"'s skin and generating at least one electrical signal in response to the at least one detected near field intensity;
c) detecting at least one far field intensity of a portion of an optical beam that is reflected from the subcutaneous vessels under the subject'"'"'s skin and generating at least one electrical signal in response to the at least one detected far field intensity;
d) determining at least one ratio of electrical signals generated in response to the at least one detected near field intensity and the at least one detected far field intensity; and
e) determining a value of hematocrit in the subcutaneous vessels illuminated by the optical beam from the at least one ratio. - View Dependent Claims (31)
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32. An apparatus for measuring hematocrit of a subject'"'"'s blood, the apparatus comprising:
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a) an illuminating means for illuminating subcutaneous vessels under a subject'"'"'s skin with an optical beam;
b) a detecting means for detecting a plurality of near field intensities of a portion of the optical beam that is reflected from the subcutaneous vessels under the subject'"'"'s skin and generating a plurality of electrical signals in response to the detected near field intensities, each of the plurality of near field intensities being detected at a unique distance relative to the subcutaneous vessels under a subject'"'"'s skin; and
c) a processing means for determining a value of hematocrit of blood in the subcutaneous vessels illuminated by the optical beam from the plurality of electrical signals.
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Specification