Patent ID: 7359750

Claim:
A method of measuring bio-impedance attributable to joint movement, comprising the steps: generating a weak current by use of a constant current source; causing the weak current to flow from a point to another point; forming L voltage detecting electrode pairs from voltage detecting electrodes positioned at m points on each of n- 1 lines that divide an interval between a first joint and a second joint, between which the weak current flows, into equal n parts, using a combination equation m C 2 =L, where m comprises the number of voltage detecting electrodes, n comprises a total number of lines between a first joint and a second joint, and L comprises the number of voltage detecting electrode pairs; detecting bio-impedance at certain periods from J voltage detecting electrode pairs that are obtained by subtracting K voltage detecting electrode pairs, each of which exists on a single dividing line, from the formed L voltage detecting electrode pairs; and selecting a pair of voltage detecting electrodes having a highest variation of bio-impedance.