Estimating the elasticity properties of arterial phantoms using fiber-based laser doppler vibrometry

Cardiovascular diseases (CVDs) are a leading cause of death worldwide. Wall stiffness is a sign of arterial health. It is known that arteries are elastic and move when the heart is pumping. One parameter which is a good predictor of cardiovascular disease is the elasticity of a patient's arteries. Currently, the index of determining arteriosclerosis in the artery can be clinically evaluated by methods such as looking at pulse transit time and at the ankle brachial pressure index. However, these indirect methods cannot determine the real status of arteries which can ultimately lead to diagnostic errors. In this research, we propose using a non-contact design configuration with an air-puff device and adopting a fiber-based laser doppler vibrometer (LDV) to measure the guided waves of arterial phantoms. We use a mechanical actuator set-up with air-puff excitation of repetition frequency at 90Hz to 180Hz to excite harmonic mechanical waves in the pipe wall. The velocity of the traveling waves were measured using fiber-based laser doppler vibrometer (LDV). The system was mounted on a linear translation stage and measured at multiple points. The wave velocity was then calculated using the signal phase difference between the different measured positions. The elastic properties of the pipe were then calculated by looking at the velocity of the guided wave dispersion. To verify the accuracy of our method, the elastic properties of the latex pipe were also measured with an atomic force microscope (AFM) and then compared to our experimental data. Results show that our experimentally obtained elastic modulus of 4.03MPa was in close agreement to the 3.19MPa of the elastic modulus obtained by the AFM. In conclusion, we propose a novel contactless method to measure the elastic properties of arteries in-vitro with high accuracy and which has good potential to be adopted for the healthcare of patients at home. © 2022 SPIE.