Body fluids monitor
First Claim
1. A process for determining a volume of whole body fluid in a subject, comprising the steps of:
- applying a signal to a subject;
increasing a frequency of the signal by predetermined increments;
measuring an impedance and a resistance of the subject at each frequency increment;
determining a total body frequency FT, wherein the total body frequency FT is the frequency at which the impedance decreases by a predefined percent over a predefined frequency interval;
determining circuit components of a human body circuit model, wherein the circuit components comprise a total body impedance ZT, a total body resistance RT, an extra-cellular resistance RE, an intra-cellular resistance RI, a capacitance C, a self-inductance L, and a mutual-inductance M; and
determining the volume of whole body fluid from the circuit components.
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Accused Products
Abstract
Method and apparatus are described for determining volumes of body fluids in a subject using bioelectrical response spectroscopy. The human body is represented using an electrical circuit. Intra-cellular water is represented by a resistor in series with a capacitor; extra-cellular water is represented by a resistor in series with two parallel inductors. The parallel inductors represent the resistance due to vascular fluids. An alternating, low amperage, multi-frequency signal is applied to determine a subject'"'"'s impedance and resistance. From these data, statistical regression is used to determine a 1% impedance where the subject'"'"'s impedance changes by no more than 1% over a 25 kHz interval. Circuit components of the human body circuit are determined based on the 1% impedance. Equations for calculating total body water, extra-cellular water, total blood volume, and plasma volume are developed based on the circuit components.
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Citations
39 Claims
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1. A process for determining a volume of whole body fluid in a subject, comprising the steps of:
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applying a signal to a subject; increasing a frequency of the signal by predetermined increments; measuring an impedance and a resistance of the subject at each frequency increment; determining a total body frequency FT, wherein the total body frequency FT is the frequency at which the impedance decreases by a predefined percent over a predefined frequency interval; determining circuit components of a human body circuit model, wherein the circuit components comprise a total body impedance ZT, a total body resistance RT, an extra-cellular resistance RE, an intra-cellular resistance RI, a capacitance C, a self-inductance L, and a mutual-inductance M; and determining the volume of whole body fluid from the circuit components. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An apparatus for determining a volume of whole body fluid in a subject, comprising of:
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means for applying a signal to a subject; means for increasing a frequency of the signal by predetermined increments; means for measuring an impedance and a resistance of the subject at each frequency increment; means for determining a total body frequency FT, wherein the total body frequency FT is the frequency at which the impedance decreases by a predefined percent over a predefined frequency interval; means for determining circuit components of a human body circuit model, wherein the circuit components comprise a total body impedance ZT, a total body resistance RT, an extra-cellular resistance RE, an intra-cellular resistance RI, a capacitance C, a self-inductance L, and a mutual-inductance M; and means for determining the volume of whole body fluid from the circuit components. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. An apparatus for determining a volume of whole body fluid in a subject, comprising:
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a signal generator configured to apply a signal to a subject and to increase a frequency of the signal by predetermined increments; an impedance analyzer configured to measure an impedance and a resistance of the subject at each frequency increment; and a data processing unit configured to determine a total body frequency FT where the impedance decreases by a predefined percent over a predefined frequency interval, determine circuit components of a human body circuit model including a total body impedance ZT, a total body resistance RT, an extra-cellular resistance RE, an intra-cellular resistance RI, a capacitance C, a self-inductance L, and a mutual-inductance M, and determine the volume of body fluid from the circuit components. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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Specification