A method for measuring a balloon expansion profile in vivo is provided. The method comprises providing a balloon with at least one sensing element as a diagnostic device, where the at least one sensing element is characterized by at least one attribute that is representative of balloon dimension； measuring the at least one attribute to obtain an observed attribute value； and estimating the balloon dimension and the balloon expansion profile based on the observed attribute value. A diagnostic kit for measuring a balloon expansion profile in vivo is also provided. The diagnostic kit comprises the diagnostic device； a measurement module for measuring an observed attribute value for the attribute； and a processor module for processing the observed attribute value to estimate the balloon expansion profile as one or more outputs.
