Body fat measurement device

1. A body fat measurement device comprising:

a trunk area electrode group including a plurality of electrodes for making contact with a surface of a measurement subject's trunk area;

a trunk area electrode group support unit, in which said trunk area electrode group is provided, for bringing at least some of the plurality of electrodes included in said trunk area electrode group into contact with the measurement subject's trunk area;

a trunk area dimension detection unit for detecting a trunk area dimension of the measurement subject;

a trunk area dimension measurement unit in which said trunk area dimension detection unit is provided;

a position detection unit that detects a relative positional relationship between said trunk area electrode group support unit and said trunk area dimension measurement unit;

an electrode selection unit that selects specific electrodes from the plurality of electrodes included in said trunk area electrode group based on the position information detected by said position detection unit;

a body impedance measurement unit that measures a body impedance of the measurement subject's body using the electrodes selected by said electrode selection unit;

a body fat mass calculation unit that calculates a body fat mass based on the body impedance measured by said body impedance measurement unit and the trunk area dimension detected by said trunk area dimension detection unit;

wherein said trunk area electrode group support unit is configured as a mat that can be disposed below the measurement subject's trunk area when the measurement subject is lying down; and

said trunk area dimension measurement unit is configured as a frame-shaped member that can be disposed so as to surround the measurement subject's trunk area when the measurement subject is lying down.

2. The body fat measurement device according to claim 1 , further comprising:

a guidance mechanism that guides said trunk area dimension measurement unit so as to be movable along a body axis direction of the measurement subject's trunk area.

3. The body fat measurement device according to claim 1 ,

wherein the plurality of electrodes included in said trunk area electrode group are disposed in rows on a primary surface of said mat.

4. The body fat measurement device according to claim 1 ,

wherein said trunk area dimension detection unit is a non-contact range sensor disposed on said frame-shaped member.

5. The body fat measurement device according to claim 1 ,

wherein said trunk area dimension measurement unit is disposed so as to be positioned at the location of the measurement subject's navel during measurement.

6. The body fat measurement device according to claim 1 ,

wherein said electrode selection unit selects, as said specific electrodes, electrodes, from among the plurality of electrodes included in said trunk area electrode group, that are disposed in an area corresponding to the location of the measurement subject's trunk area at which the trunk area dimension is detected using said trunk area dimension measurement unit.

7. The body fat measurement device according to claim 1 ,

wherein the plurality of electrodes included in said trunk area electrode group are electrodes for making contact with a surface of a back area that is an area of the measurement subject's trunk area on a back side.

8. The body fat measurement device according to claim 1 ,

wherein the body fat mass calculation unit includes at least one of a visceral fat mass calculation unit that calculates the visceral fat mass of the measurement subject and/or a subcutaneous fat mass calculation unit that calculates the subcutaneous fat mass of the measurement subject.