Bioelectrical impedance measuring apparatus

• US 6,714,814 B2
• Filed: 03/19/2001
• Issued: 03/30/2004
• Est. Priority Date: 03/30/2000
• Status: Active Grant

• Current Assignee: Tanita Corporation (Tanita)
• Original Assignee: Tanita Corporation (Tanita)
• Inventors: Miyoshi, Tsutomu, Ishigooka, Maki, Fukuda, Yoshinori, Yamada, Yasushi, Takehara, Katsumi
• Primary Examiner(s): Bennett, Henry
• Assistant Examiner(s): DAHBOUR, HENRY
• Application Number:
  US09/810,172
• Publication Number:
  US 20010030546A1
• Time in Patent Office: 1,107 Days
• Field of Search: 600/547, 600/548, 600/372, 600/382, 600/384, 600/393, 600/383, 600/386, 324/691, 324/692
• US Class Current: 600/547
• CPC Class Codes: A61B 2560/0406 specially shaped apparatus housings
• 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

Abstract

Disclosed is a impedance measuring apparatus which is easy to use, and which is guaranteed to be free of incorrect measurement caused by some joints appearing in the current flowing passage intervening between two selected body parts and by the indefinite length between two selected body parts. The measuring apparatus of the present invention limits the place of the body under measurement to “one body region”, i.e. a selected joint-to-joint body portion or joint-free body portion such as the forearm extending from the wrist to the elbow or the portion extending from the ankle to the knee, and comprises a housing having a contact surface to be applied to one selected body region; a first pair of measurement current supplying electrodes so placed on the contact surface that the one selected body region may be put in contact with the current electrodes; and a first pair of voltage measuring electrodes so placed on the contact surface between the pair of current electrodes that the one selected body region may be put in contact with the voltage electrodes.

Claims

1. A bioelectrical impedance measuring apparatus characterized in that it comprises:

a housing having a contact surface to be applied to one selected body region, the housing having a first pair of current electrodes, a first pair of voltage electrodes, an alternative current supplying device, a voltage measuring device and an arithmetic unit equipped therewith;

the first pair of current electrodes so placed on the contact surface that the one selected body region may be put in contact with the current electrodes; and

the first pair of voltage electrodes so placed on the contact surface between the pair of current electrodes that the selected one body region may be put in contact with the voltage electrodes;

the alternating current supplying device supplying the first pair of current electrodes with alternating current;

the voltage measuring device measuring the voltage appearing between the pair of voltage electrodes; and

the arithmetic unit calculating the bioelectrical impedance from the supplying alternating current and the measured voltage;

wherein the first pair of current electrodes and the first pair of voltage electrodes stand in one line.

2. A bioelectrical impedance measuring apparatus according to claim 1 wherein the housing includes a rest whose upper surface defines the contact surface to be applied to the selected one body region, the contact surface being like a semi-cylindrical trough, and the current and voltage electrodes being so curved that they may be almost coplanar with the semi-cylindrical contact surface.

3. A bioelectrical impedance measuring apparatus according to any of claim 2 wherein it further comprises a positioning member which permits the one selected body region to be put in correct position, the positioning member being capable of effecting so positional adjustment as to fit on the one selected body region.

4. A bioelectrical impedance measuring apparatus according to claim 3 wherein the one selected body region is the right or left forearm, and the positioning member is a hand grip and/or an elbow rest.

5. A bioelectrical impedance measuring apparatus according to claim 1 wherein it further comprises a cover member capable of pushing the one selected body region against the two pairs of electrodes.

6. A bioelectrical impedance measuring apparatus according to claim 5 wherein:

a second pair of current electrodes and a second pair of voltage electrodes are placed on the surface of the cover member which surface confronts the contact surface of the rest, the second electrodes being arranged in the same order and at same intervals as the counter first electrodes, thus sandwiching the one selected body region therebetween;

the alternating current supplying device supplies one and same alternating current to the first and second pairs of current electrodes simultaneously, making the two sets of confronting current electrodes function as a single composite pair of current electrodes; and

the voltage measuring device measures the voltage appearing between the first and second pairs of voltage electrodes, making the two sets of confronting voltage electrodes function as a single composite pair of voltage electrodes.

7. A bioelectrical impedance measuring apparatus according to claim 1 wherein the housing includes a rest whose upper surface defines the contact surface to be applied to the one selected body region, and a cover member pivotally fixed to one longitudinal edge of the rest, thereby permitting the one selected body region to be sandwiched between the rest and the cover member which is put in its closed position;

and

the first pairs of current and voltage electrodes are placed on the surface of the cover member instead of the contact surface to push the two pairs of electrodes against the one selected body region lying on the contact surface of the rest.

8. A bioelectrical impedance measuring apparatus according to claim 7 wherein it further comprises a positioning member which permits the one selected body region to be put in correct position, the positioning member being capable of effecting so positional adjustment as to fit on the one selected body region.

9. A bioelectrical impedance measuring apparatus according to claim 8 wherein the one selected body region is the right or left forearm, and the positioning member is a hand grip and/or an elbow rest.

10. A bioelectrical impedance measuring apparatus according to claim 1 wherein the one selected body region is the right or left forearm.

11. A bioelectrical impedance measuring apparatus according to claim 1 wherein the one selected body region is the part of the right or left leg below the knee and above the ankle.

12. A bioelectrical impedance measuring apparatus according to claim 1 wherein it further comprises a display placed on a selected place of the housing other than the contact surface.

13. A bioelectrical impedance measuring apparatus according to claim 12 wherein the housing is so shaped and sized that a user can hold it in one hand while applying the contact surface to the one selected body region, still permitting the display to remain in sight.

14. A bioelectrical impedance measuring apparatus according to claim 13 wherein the housing has indentations formed on its opposite sides, on which indentations the fingers are placed, thereby facilitating the holding of the housing in one hand.

15. A bioelectrical impedance measuring apparatus according to any one of claim 12 wherein the display is so arranged that the vertical direction of the display is orthogonally traverse to the direction in which the first pairs of current and voltage electrodes are aligned side by side, thereby facilitating the seeing of the information appearing in its screen.

16. A bioelectrical impedance measuring apparatus according to claim 1 wherein:

the housing has a display placed at a selected place other than the contact surface and a grip portion;

a recess is so formed between the first pair of voltage electrodes that the contact surface space is reduced.

17. A bioelectrical impedance measuring apparatus according to claim 16 wherein the housing is so shaped and sized that a user can hold it with one hand while applying the contact surface to the one selected body region, still permitting the display to remain in sight.

18. A bioelectrical impedance measuring apparatus according to claim 16 wherein the grip portion is so formed to surround the recess, thereby facilitating the holding of the housing in one hand.

19. A bioelectrical impedance measuring apparatus according to any one of claim 16 wherein the display is so arranged that the vertical direction of the display is orthogonally traverse to the direction in which the first pairs of current and voltage electrodes are aligned side by side, thereby facilitating the seeing of the information appearing in its screen.

20. A bioelectrical impedance measuring apparatus according to claim 1 wherein the arithmetic unit further calculates at least one of body fat, body water, pulse, or blood pressure.

21. A bioelectrical impedance measuring apparatus according to claim 1 wherein:

the alternating current supplying device supplies a plurality of alternating currents of different frequencies;

the voltage measuring device measures the voltage every time when an alternating current of selected frequency is supplied; and

the arithmetic unit calculates the bioelectrical impedance values from each alternating current and corresponding voltage.

22. A bioelectrical impedance measuring apparatus according to claim 21 wherein the arithmetic unit further calculates at least one of the ratio between extra-cellular water and intra-cellular water, the ratio of body water and extra-cellular water, intra-cellular water, extra-cellular water, body water, or body fat.

23. A bioelectrical impedance measuring apparatus according to claim 1 wherein:

the alternating current supplying device supplies an alternating current of a single frequency;

the voltage measuring device further measures the phase of the voltage measured by it; and

the arithmetic unit further calculates the phase difference between the phase of the supplying alternating current and the phase of the measured voltage.

24. A bioelectrical impedance measuring apparatus characterized in that it comprises:

a rest on which one selected body region may be put;

a pair of current electrodes so placed on the rest that the one selected body region may be put in contact with the current electrodes;

a pair of voltage electrodes so placed on the contact surface between the pair of current electrodes that the one selected body region may be put in contact with the voltage electrodes;

a position member which permits the one selected body region to be put in correct position;

an alternating current supplying device which supplies the pair of current electrodes with alternating current;

a voltage measuring device which measures the voltage appearing between the pair of voltage electrodes; and

an arithmetic unit which calculates the bioelectrical impedance from the supplying alternating current and the measured voltage.

25. A bioelectrical impedance measuring apparatus characterized in that it comprises;

a rest on which one selected body region may be put;

a pair of current electrodes so placed on the rest that the one selected body region may be put in contact with the current electrodes;

a pair of voltage electrodes so placed on the contact surface between the pair of current electrodes that the one selected body region may be put in contact with the voltage electrodes;

a cover member capable of pushing the one selected body region against the two pairs of electrodes;

an alternating current supplying device which supplies the pair of current electrodes with alternating current;

a voltage measuring device which measures the voltage appearing between the pair of voltage electrodes; and

an arithmetic unit which calculates the bioelectrical impedance from the supplying alternating current and the measured voltage.

26. A bioelectrical impedance measuring apparatus characterized in that it comprises:

a rest on which one selected body region may be put;

a cover member so pivotally fixed to one longitudinal edge of the rest that the one selected body region may be sandwiched between the rest and the cover member which is put in its closed position;

a pair of current electrodes and a pair of voltage electrodes so placed on the surface of the cover member to push the two pairs of electrodes against the one selected body region lying on the contact surface of the rest, the pair of voltage electrodes intervening between the pair of current electrodes;

an alternating current supplying device which supplies the pair of current electrodes with alternating current;

a voltage measuring device which measures the voltage appearing between the pair of voltage electrodes; and

an arithmetic unit which calculates the bioelectrical impedance from the supplying alternating current and the measured voltage.

27. A bioelectrical impedance measuring apparatus characterized in that it comprises:

a housing having a contact surface to be applied to one selected body region and a grip portion, the housing having an alternating current supplying device, a voltage measuring device and an arithmetic unit equipped therewith;

a pair of current electrodes so placed on the contact surface that the one selected body region may be put in contact with the current electrodes;

a pair of voltage electrodes so placed on the contact surface between the pair of current electrodes that the selected one body region may be put in contact with the voltage electrodes; and

a display placed on a selected place of the housing other than the contact surface;

the alternating current supplying device supplying the first pair of current electrodes with alternating current;

the voltage measuring device measuring the voltage appearing between the pair of voltage electrodes;

the arithmetic unit calculating the bioelectrical impedance from the supplying alternating current and the measured voltage; and

a recess being so formed between the first pair of voltage electrodes that the contact surface space is reduced.