Engineering-Based Contributions in Cryobiology.

Over the past three decades there has been an increasing number of engineering-trained researchers who have made the field of cryobiology a primary focus of their work. In prior times the advances in cryobiology were accomplished nearly exclusively by members of the life and medical science communities. In general, the practice of engineering may be distinguished by two features: an emphasis on rigorous quantitative measurement and analysis of processes and the synthesis of an understanding of fundamental principles of nature into the design of novel devices and processes for specific applications. One area of focus in cryobiology that engineers have emphasized is the design of new apparatus, including both experimental instrumentation and clinical diagnostic and therapeutic devices. There has been a broad spectrum of new apparatus invented to enable the quantitative control and measurement of the fundamental phenomena that govern processes in cryobiology. Among these are low-temperature cryomicroscopy stages and mass diffusion chambers, which now are often used in conjunction with digital image analysis algorithms to quantify changes to individual cells and tissues elicited during the process being studied. Other applications include the development of novel measurement techniques for assessing system properties and states during freezing and thawing. In cryosurgery and in cryopreservation new probes and apparatus have been designed to provide more accurate and effective processes to achieve clinical objectives. Equally important and complementary to the design of hardware is the development of analytical models which can be applied to understand and interpret experimental data and to predict the behavior of systems for operation in domains beyond those for which empirical data are available. Perhaps the most critical role of these models is for inverse solution techniques with experimental data to obtain values for the intrinsic constitutive properties of tissues which govern their response to freezing and thawing processes.