Thermal stress in blood vessels during cryopreservation processes

A crucial problem in the cryopreservation of human blood vessels is fracture in the frozen tissue caused by thermal stress. A finite element model of human blood vessel was developed to investigate heat transfer and the thermal stress in blood vessels during the cooling process. Results from computer simulation indicates that the magnitude and distribution of the thermal stress in blood vessels are greatly affected by cooling rate and the nature of the constitutive law of the frozen biomaterial. A low cooling rate generates much lower thermal stress than a high cooling rate, and hence should be used in the cryopreservation.