ABSTRACT
Objective To study a quantitative indicator for measuring the similarity between blood pressure waveforms and its application in the analysis on the simulated blood pressure waveform for pulsatile flow simulation system.Methods Based on the past similarity measurement algorithm and the known feature of blood pressure waveforms, the weighted average algorithm was presented in this paper, which possessed advantages of both global matching and partial matching by integrating the correlation coefficient with the characteristic parameter algorithm, and calculating similarity degrees through overall and partial waveform.Results The weighted average algorithm was proved to be more suitable for the analysis on the blood pressure waveform similarity compared with the angle cosine method, average absolute deviation method, and numeric similarity coefficient method.Conclusions The weighted average algorithm showed excellent ability in calculating the similarity degree between different waveforms, or in comparing the performance with different pulsatile flow simulation systems, and it could be applied to other physiological waveforms with further improvement.
ABSTRACT
Objective To study the flow field of a new vascular bioreactor with small diameter at different operating conditions. Method To investigate the flow field of a new vascular bioreactor with small diameter under three operating conditions by numerical simulation: outer box rotating, inner box rotating and both inner box and outer box rotating. A comparison of parameters such as flow velocity and shear stress was made. Results The culture medium in the bioreactor rotated with the inner box and outer box, and the velocity was uniformly distributed; the bioreactor could therefore provide a low shear stress environment that is nondestructive for the cells in the medium; the shear stress in bioreactor had a quadratic function relation with the rotation rate. Conclusions This bioreactor could provide a good culture environment for vascular tissue regeneration, and this study provided theoretical basis for the experimental research of bioreactors.