A method performed by a computer correlates vesicoelastic pressure data (10, 12, 14) with volume data and calculates vesicoelastic work performed by the bladder (20), wherein the amount of vesicoelastic work performed by the bladder (20) is determined by calculating an area under said vesicoelastic pressure data (10, 12, 14) when said vesicoelastic pressure data (10, 12, 14) is correlated against the volume data.
