Numerical investigation of rapid and uniform microwave rewarming in large-scale cryopreserved human heart

Organ transplantation is a critical medical technology for reducing mortality and extending human lifespan. Low-temperature storage is essential for extending ex vivo preservation time, which is a prerequisite for successful organ transplantation. However, the requirement for rapid rewarming after preservation can induce large internal temperature difference, particularly in large-scale organs. Currently, microwave heating and nano-warming are the primary approaches for achieving rapid rewarming. In this study, the feasibility of microwave heating for rapid and uniform rewarming of large-scale organs is systematically investigated. And the organ is mechanically rotated to spatially average electromagnetic energy deposition and reduce temperature gradient. Numerical simulations demonstrate that, under microwave irradiation at 700 MHz with an input power of 1500 W, the organ can be rewarmed from 123.15 K to 273.15 K within 140 s. The temperature gradient is 78 K, 43 K lower than in the static state. These results indicate that microwave heating has significant potential to achieve rapid and uniform rewarming of large-scale organs without the use of nanoparticles.