iFR - Method and system for computation of start time of wave-free period for calculation of iFR for determination of treatment of intermediate coronary artery stenosis

摘要

A system for calculating the start time of a wave-free section for calculating iFR comprises: a pressure sensor inserted into the coronary artery to detect the blood pressure of each of proximal and distal sites positioned before and after a narrow site and output a corresponding signal; and an iFR processing unit calculating iFR by processing and calculating the signal of the pressure sensor. The iFR processing unit is configured to perform a logic including the steps of: calculating a difference in pressure between the blood pressure (Pa) of the proximal site and the blood pressure (Pd) of the distal site; differentiating the calculated pressure difference; squaring the differentiated value; calculating a square integral of the squared value; and determining a corresponding time as the start time of a wave-free section for calculating iFR when the square integral value reaches a preset threshold. Therefore, iFR can be calculated in a simple and physiologically rational method by using a new algorithm.