Methods and devices for non-invasively measuring quantitative information of substances in living organisms

• US 7,395,104 B2
• Filed: 03/06/2005
• Issued: 07/01/2008
• Est. Priority Date: 03/06/2004
• Status: Expired due to Fees

• Current Assignee: Kehaai Incorporated
• Original Assignee: Calisto Medical, Inc.
• Inventors: Hambardzumyan, Minas, Farmanyan, Gagik, Malkin, Maksim, Mouradian, Vahram, Armenakyan, Valeri
• Primary Examiner(s): Marmor, II; Charles A.
• Assistant Examiner(s): Natnithithadha; Navin
• Application Number:
  US11/074,283
• Publication Number:
  US 20050197555A1
• Time in Patent Office: 1,213 Days
• Field of Search: 600/309, 600345-366
• US Class Current: 600/347
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement

Abstract

Disclosed are systems and methods of determining the amount of a substance in a living organism. In one embodiment, the method comprises: applying an electrical signature signal to the living organism, wherein the electrical signature signal corresponds to a predetermined amount of the substance; measuring the response of the living organism to the applied signature signal; and determining whether an elevated response has resulted from applying the electrical signature signal, if so, then determining the amount of the substance in the living organism from the predetermined amount of the substance.

Claims

1. A method for determining the amount of glucose in a human body, the method comprising:

(a) providing a plurality of electrical signature signals, wherein each electrical signature signal corresponds to a predetermined indicator of glucose;

(b) applying an electrical signature signal from the plurality of electrical signals to at least two electrodes;

(c) measure a first change in impedance over time resulting from the application of the electrical signature signal to produce a first set of measured data;

(d) applying the electrical signature signal from the plurality of electrical signals to the two electrodes;

(e) measure a second change in impedance over time resulting from the application of the second electrical signature signal to produce a second set of measured data;

(f) determining whether the first set of measure data and the second set of measured data have converged, if yes, then storing the first set and second set as a candidate data set;

(g) determining whether all of the electrical signature signals in the plurality of electrical signature signals have been applied,

if no, then selecting a new electrical signature signal and repeating steps (b) through (g);

if yes, then;

selecting the candidate set having a maximum level of convergence, and determining the amount of substance from the electrical signature signal producing the selected candidate set.

2. The method of claim 1, farther comprising:

measuring the electrical impedance between the electrodes to obtain a signal indicating the electrical impedance,

amplifying the signal indicating the electrical impedance,

determining whether the amplified signal is within a predetermined criteria, if not, then;

calculating a gain factor,

adjusting an amplifier using the gain factor; and

re-measuring the electrical impedance between the electrodes to obtain a signal indicating the electrical impedance.

3. The method of claim 1 further comprising clearing residual voltage between the at least two electrodes.

4. A method of determining a substance in a living organism, the method comprising:

(a) providing a plurality of electrical signature signals, wherein each electrical signature signal corresponds to a predetermined indicator of the substance;

(b) applying an electrical signature signal from the plurality of electrical signals to at least two electrodes;

(c) measure a first change in impedance over time resulting from the application of the electrical signature signal to produce a first set of measured data;

(d) applying the electrical signature signal from the plurality of electrical signals to the two electrodes;

(e) measure a second change in impedance over time resulting from the application of the second electrical signature signal to produce a second set of measured data;

(f) determining whether the first set of measure data and the second set of measured data have converged, if yes, then storing the first set and second set as a candidate data set;

(g) determining whether all of the electrical signature signals in the plurality of electrical signature signals have been applied, if no, then selecting a new electrical signature signal and repeating steps (b) through (g);

if yes, then;

selecting the candidate set having a maximum level of convergence, and

determining the amount of substance from the electrical signature signal producing

the selected candidate set.

5. The method of claim 4, further comprising:

measuring the electrical impedance between the electrodes to obtain a signal indicating the electrical impedance,

amplifying the signal indicating the electrical impedance, determining whether the amplified signal is within a predetermined criteria, if not, then;

calculating a gain factor,

adjusting an amplifier using the gain factor; and

re-measuring the electrical impedance between the electrodes to obtain a signal indicating the electrical impedance.

6. The method of claim 4 further comprising clearing residual voltage between the at least two electrodes.