Non-invasive Pulse Wave Velocity Measurement in Mice

Atherosclerosis, hardening of the arteries, causes heart attacks and strokes that are recorded as the world's number one killer disease. Nowadays, research on atherosclerosis is still limited because the modeling of atherosclerotic animals is difficult to do. Pulse wave velocity (PWV) is used clinically as a measure of arterial stiffness. PWV measurements in animals can be done invasively and non-invasively. PWV values have a strong correlation with cardiovascular conditions. This study aimed to create a PWV measuring instrument in mice to estimate the occurrence of atherosclerosis. The device developed will be highly beneficial in enhancing the research and development of anti-atherosclerotic drugs. PWV measurement was performed non-invasively by using electrocardiogram (ECG) and photoplethysmogram (PPG) sensors. The ECG electrode was placed on the left and right front legs and right rear leg of the test animal. While the PPG sensor placed on the rat tail. PWV is the traveling speed along the arterial segment from the heart position point to the PPG sensor position at the base of the tail. By comparing the EKG and PPG waveforms the amount of travel time (Pulse transit time, PTT) can be determined. The measurement results were obtained in less than a minute. The average PWV measurement results with the proposed method in normal mice aged one to three months was 480 cm/s, within the range of the results obtained by existing standard methods.