Determining body composition through segmental bioelectrical impedance analysis (BIA)

摘要

An apparatus includes an analysis circuit and a controller. The analysis circuit may be configured to automatically make a plurality of segmental bioelectrical resistance and reactance measurements using permutations of a plurality of electrodes selected four at a time. The plurality of electrodes are configured to be attached to predetermined locations on a body of a subject. The controller may be configured to (i) calculate a plurality of segmental body composition values using the plurality of segmental bioelectrical resistance and reactance measurements, a number of predetermined coefficients, and a number of predictive equations, and (ii) generate a report presenting the plurality of segmental body composition values and a total body composition value. The number of predetermined coefficients are stored in a lookup table. Each of the segmental body composition values when added sum to a value essentially equal to respective whole body composition values.

主权项

1. An apparatus comprising:
an analysis circuit configured to automatically make a plurality of segmental bioelectrical resistance and reactance measurements using permutations of eight electrodes selected four at a time, wherein (i) the analysis circuit is further configured to utilize a constant current source to maintain an input current, which is injected into a subject, constant at a predetermined value by supplying the input current to the subject via a first pair of the four selected electrodes, comparing the current through said subject to a reference, and adjusting the input current based on the comparison, and (ii) said eight electrodes are configured to be attached to predetermined locations on a body of said subject while in a supine position; and a controller configured to (i) calculate a plurality of segmental body composition values and a plurality of whole body composition values using said plurality of segmental bioelectrical resistance measurements, a number of predetermined coefficients, a height of said subject, a weight of said subject, a gender of said subject, and a number of predictive equations, and (ii) generate a report presenting at least one set of said plurality of segmental body composition values and said whole body composition values, wherein (i) said number of predetermined coefficients are stored in a lookup table, (ii) each of said number of predictive equations expresses a correlation between a respective segmental or respective whole body composition value and one or more of said plurality of segmental bioelectrical resistance measurements, such that a sum of a set of individual segmental body composition values is essentially equal to a respective whole body composition value, allowing each value in the set to be calculated from the other values in the set and the respective whole body composition value, (iii) said plurality of segmental body composition values comprises sets of lean mass values, no bone mass values, and fat mass values, and (iv) said lean mass values are calculated using an equation having a general form of Segmental Lean Mass Value=C1*exp(C2*log(segmental bioelectrical resistance measurement)+C3*log(height)−C4)+C5*weight−C6, where the coefficients C1 through C6 represent predetermined coefficients, corresponding to respective body segments, stored in said lookup table.