An apparatus for measuring a bio-signal includes a pulse wave sensor that may measure a pulse wave signal, of an object of interest, that is non-equidistantly sampled based on a sampling rate of the pulse wave sensor, and a processor that may identify, using a sampling profile, a first interval based on a health index to be measured. The processor may identify, using the sampling profile, a second interval based on the health index to be measured. The processor may set the sampling rate of the pulse wave sensor to a first sampling rate in the first interval. The processor may set the sampling rate of the pulse wave sensor to a second sampling rate, that is less than the first sampling rate, in the second interval.
