Bioelectric impedance measuring apparatus

• US 6,473,641 B1
• Filed: 09/29/2000
• Issued: 10/29/2002
• Est. Priority Date: 09/30/1999
• Status: Active Grant

• Current Assignee: Tanita Corporation (Tanita)
• Original Assignee: Tanita Corporation (Tanita)
• Inventors: Kodama, Masato, Yoshida, Yoshikazu
• Primary Examiner(s): Shaver, Kevin
• Assistant Examiner(s): SZMAL, BRIAN SCOTT
• Application Number:
  US09/672,899
• Time in Patent Office: 760 Days
• Field of Search: 600/547, 600/300, 607/66, 128/897, 128/898
• 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 5/441 Skin evaluation, e.g. for skin disorder diagnosis
• CPC Class Codes: A61B 5/4869 Determining body composition
• CPC Class Codes: A61B 5/4872 Body fat

Abstract

Disclosed is a bioelectric impedance measuring apparatus which can prevent such abnormal condition than an excessive current is applied to a human body when elements in the circuit has failed or is damaged, with a simple circuit configuration and without decreasing the measuring accuracy of the bioelectric impedance. The bioelectric impedance measuring apparatus according to the present invention is configured such that a capacitor or a set of a capacitor and a resistor arranged in parallel with each other is installed between an electrode to be brought into contact with a human body and a bioelectric impedance measuring circuit section comprising a generating section for generating an alternating current applied to a human body for measurement, a measuring section for measuring a voltage value between the portions where the current is applied to the human body, a computing section for computing a bioelectric impedance value, and a central processing unit (CPU).

Claims

1. A bioelectrical impedance measuring apparatus comprising a plurality of electrodes including current electrodes and voltage electrodes for contacting the skin of a person to be measured, an alternating current generating unit connected to said current electrodes so that an alternating current may be flowed into the body of the person, a voltage measuring unit connected to said voltage electrodes so that a voltage between said voltage electrodes may be measured, and a bioelectrical impedance determining unit for determining the bioelectrical impedance of the body of the person on the basis of the alternating current flowed into the body of the person and the measured voltage, said apparatus further comprising a parallel circuit of a capacitor and a resistor between said alternating current generating unit and said current electrodes.

2. A bioelectrical impedance measuring apparatus as defined in claim 1, further comprising a diode for electrostatic safety countermeasure between said alternating current generating unit and said parallel circuit capacitor and resistor.

7. A bioelectrical impedance measuring apparatus as defined in any one of claims 1 to 6, wherein said electrodes are for contacting the skin of the feet of the person, and said measured bioelectrical impedance is measured between the feet of the person.

3. A bioelectrical impedance measuring apparatus comprising a plurality of electrodes including current electrodes and voltage electrodes for contacting the skin of a person to be measured, an alternating current generating unit connected to said current electrodes so that an alternating current may be flowed into the body of the person, a voltage measuring unit connected to said voltage electrodes so that a voltage between said voltage electrodes may be measured, and a bioelectrical impedance determining unit for determining the bioelectrical impedance of the body of the person on the basis of the alternating current flowed into the body of the person and the measured voltage, said apparatus further comprising a parallel circuit of a capacitor and a resistor between said voltage measuring unit and said voltage electrodes.

4. A bioelectrical impedance measuring apparatus as defined in claim 3, further comprising a diode for electrostatic safety countermeasure between said voltage measuring unit and said parallel circuit of capacitor and resistor.

5. A bioelectrical impedance measuring apparatus comprising a plurality of electrodes including current electrodes and voltage electrodes for contacting the skin of a person to be measured, an alternating current generating unit connected to said current electrodes so that an alternating current may be flowed into the body of the person, a voltage measuring unit connected to said voltage electrodes so that a voltage between said voltage electrodes may be measured, and a bioelectrical impedance determining unit for determining the bioelectrical impedance of the body of the person on the basis of the alternating current flowed into the body of the person and the measured voltage, said apparatus further comprising a first parallel circuit of a capacitor and a resistor between said alternating current generating unit and said current electrodes and a second parallel circuit of a capacitor and a resistor between said voltage measuring unit and said voltage electrodes.

6. A bioelectrical impedance measuring apparatus as defined in claim 5, further comprising a diode for electrostatic safety countermeasure between said alternating current generating unit and said first parallel circuit of capacitor and resistor and a diode for electrostatic safety countermeasure between said voltage measuring unit and said second parallel circuit of capacitor and resistor.