Purpose: We developed a modified Kelvin model so that the periodic changes of the arterial intima-media thickness (IMT) over the cardiac cycle were involved. Modified model was implemented for carotid artery, solved via a parameter optimization technique and biomechanical parameters of the model.
Methods: Consecutive ultrasonic images of the common carotid artery of 30 male patients including 10 healthy subjects, 10 subjects with mild and 10 subjects with sever stenosis were recorded and processed offline. Temporal changes of the internal diameter and IMT were extracted using a combined maximum gradient and dynamic programming algorithm. The blood pressure waveforms were deduced calibrating the internal diameter waveforms using an empirical exponential relationship.
Results: According to the results of the ANOVA statistical analysis, mean values of the zero pressure radiuses, stress relaxation times, elastic moduli and strain relaxation times of the common carotid arteries of three groups were significantly different. Mentioned parameters increased 11, 24, 7 and 6% in patients with mild (< 50%) stenosis and 12, 73, 8 and 61% in the group with sever stenosis (> 50%) relative to healthy group.
Conclusion: Present study can be an indicative of the general state of the vascular system and be used for discriminating atherosclerotic from healthy arteries.
Keywords: Biomechanical properties; Carotid artery; Parameter optimization; Ultrasonic images.