Device and method for measuring the composition of the body

• US 6,208,890 B1
• Filed: 03/01/1999
• Issued: 03/27/2001
• Est. Priority Date: 03/03/1998
• Status: Expired due to Fees

• Current Assignee: SEB SA
• Original Assignee: SEB SA
• Inventors: Sarrazin, Michel, Duborper, Alain
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US09/260,154
• Time in Patent Office: 757 Days
• Field of Search: 600/547
• US Class Current: 600/547
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/4869 Determining body composition
• CPC Class Codes: A61B 5/4872 Body fat
• CPC Class Codes: G01G 19/44 for weighing persons

Abstract

A device for measuring the composition of the body of a person includes a first electronic module which measures a bioelectrical impedance and including at least one current source which delivers a variable electrical signal that passes through the body of the person when the person is connected to the measuring device. The electrical signal is a squarewave the duration of which is variable to determine the global impedance, the intracellular impedance and the extracellular impedance of the body of the person directly.

Claims

1. A method for measuring a bioelectrical impedance of a person'"'"'s body, said method comprising the steps of:

applying at least a first and a second pair of electrodes on a person'"'"'s body;

applying a periodic electrical signal having a square wave shape between said first pair of electrodes connected to said body;

measuring voltage values between said at least second pair of electrodes also connected to said body, at times when a capacitive component of said voltage value is cancelled due to the square shape of said electrical signal;

determining from said measured voltage values a bioelectrical impedance value; and

displaying said bioelectrical impedance value.

2. The method claimed in claim 1 further comprising the steps of:

measuring a weight value of said person; and

determining and displaying a fat body mass, a lean body mass and an amount of water contained in said person'"'"'s body from said weight value and said bioelectrical impedance value.

3. The method claimed in claim 1 further comprising a step of adjusting a period of said electrical signal by said processor unit as a function of measurements to be performed.

4. The method claimed in claim 1 further comprising a step of cancelling said electrical signal in a middle of each half-wave so as to totally cancel the capacitive effect of said body.

5. A device for measuring the composition of the body of a person, said device comprising:

a first electronic module adapted to measure a bioelectrical impedance and including at least one current source adapted to deliver a periodic electrical having a square wave shape, said current source being connected to two excitation electrodes adapted to be connected to a person'"'"'s body; and

a measuring unit for measuring a voltage value between two measuring electrodes adapted to be connected to said body;

a computing module comprising means for determining a bioelectrical impedance of said body as a function of voltage values provided by said measuring unit; and

a display unit for displaying said bioelectrical impedance.

6. The device claimed in claim 5 wherein said computing module further comprises means for determining an intracellular impedance and an extracellular impedance of said person'"'"'s body from said voltage value.

7. The device claimed in claim 5 further comprising a second electronic module for measuring a weight of said person'"'"'s body, said computing module further comprising means for determining from the measured weight and said measured bioelectrical impedance of a fat body mass, a lean body mass and an amount of water contained in said body.

8. The device claimed in claim 5 wherein said electrical signal has a frequency chosen in the range of 2-400 kHz.

9. Scales for weighing a person comprising:

an upper horizontal pan;

a first electronic module for measuring a weight of a person standing on said pan;

a second electronic module for measuring a bioelectrical impedance of said person, said second electronic module including at least one current source adapted to deliver a periodic electrical signal of square wave shape which is applied to the body of said person through a first pair of electrodes and a measuring unit for measuring a voltage value between a second pair of electrodes, said first and second pair of electrodes being disposed to be in contact with said body when said person is standing on said pan;

a computing module for determining a bioelectrical impedance of said body as a function of said voltage value and a fat body mass, a lean body mass and an amount o water contained in said body as function of said bioelectrical impedance and said measured weight; and

display means for displaying said bioelectrical impedance, said fat body mass, said lean body mass and said amount of water contained in said body.