Body water amount condition judging apparatus by multi-frequency bioelectric impedance measurement

• US 20020022787A1
• Filed: 08/01/2001
• Published: 02/21/2002
• Est. Priority Date: 08/01/2000
• Status: Active Grant

• Current Assignee: Tanita Corporation (Tanita)
• Original Assignee: Tanita Corporation (Tanita)
• Inventors: Takehara, Tomoko, Takehara, Katsumi
• Granted Patent: US 6,643,543 B2
• Time in Patent Office: Days
• US Class Current: 600/547
• CPC Class Codes: A61B 2560/0468 Built-in electrodes
• 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 5/4878 Evaluating oedema

Abstract

A body water amount condition judging apparatus which is capable of judging body water amount condition, such as edema or dehydration, in detail exactly is disclosed. In the apparatus, at least two values selected from intra-cellular water resistance, extra-cellular water resistance, combined resistance of the intra-cellular and extra-cellular water resistance, and a ratio of intra-cellular and extra-cellular water are judging parameters for body water amount condition, The apparatus comprises a multi-frequency bioelectric impedance measuring means for measuring bioelectric impedance using AC currents having different frequencies, a calculating means for calculating each value of a judging parameter based on the measured bioelectric impedance value, a body water amount condition judging means for judging body water amount condition based on the calculated each value of the judging parameter, and a display means for displaying the judging result of the body water amount condition so judged.

Claims

1. A body water amount condition judging apparatus, in which at least two values selected from intra-cellular water resistance, extra-cellular water resistance, combined resistance of the intra-cellular and extra-cellular water resistance, and a ratio of intra-cellular and extra-cellular water are judging parameters for body water amount condition, comprising;

a multi-frequency bioelectric impedance measuring device;

a calculating device;

a reference value determining unit;

a body water amount condition judging unit; and

a display device;

wherein,

said multi-frequency bioelectric impedance measuring device supplies a plurality of alternating current of different frequencies to a body of a subject and measures a bioelectric impedance value,

said calculating device calculates the values of each judging parameter based on the bioelectric impedance value measured,

said reference value determining unit determines reference values of the same kind based on judging parameter values calculated prior to each judging parameter of the same kind calculated in the past,

said body water amount condition judging unit judges body water amount condition by comparing each calculated judging parameter value with the determined judging parameters of the kind, and

said display device displays the judging result of said body water amount condition so judged.

2. An apparatus according to claim 1 wherein;

said calculating device further calculates at least one of the values of intra-cellular water content, extra-cellular water content and total body water content.

3. An apparatus according to claim 1 or 2 wherein;

said reference value determining unit determines that an average value of each judging parameter of the past is a reference value of a judging parameter of the same kind.

4. An apparatus according to claim 1 or 2 wherein;

said reference value determining unit determines that the latest value in judging parameters of the past is a reference value of a judging parameter of the same kind.

5. An apparatus according to any one of claims 1 to 4 wherein;

said reference value determining unit determines a reference value of a judging parameter every time the judging parameter is calculated.

6. An apparatus according to any one of claims 1 to 5 wherein;

said reference value determining unit does not use a value of a judging parameter for determining a reference value of the judging parameter, when the value of the judging parameter is abnormal.

7. An apparatus according to claim 6 wherein;

said reference value determining unit determines that a value of a judging parameter is abnormal, when the difference between each value of the judging parameter and a reference value of the judging parameter of the same kind which is already determined exceeds the predetermined value.

8. An apparatus according to claim 6 or 7 wherein;

said reference value determining unit determines whether a value of a judging parameter is abnormal or not depending upon the time a bioelectric impedance value is determined for calculating the value of the judging parameter.

9. An apparatus according to any one of claims 6 to 8 further comprising:

an abnormal value selecting device;

wherein;

said abnormal value selecting device decides whether a subject uses a value of a judging parameter for determining a reference value or not;

said reference value determining unit determines whether the value of the judging parameter is abnormal or not responding to said abnormal value selecting device.

10. An apparatus according to claim 8 wherein;

said reference value determining unit decides that a value of a judging parameter is abnormal if the time a bioelectric impedance value is determined for calculating the value of the judging parameter is in the hour of rising for the subject.