The first incubators for embryo culture were large and the embryos of all patients were stored in the same space. Therefore, when a patient's embryos had to be removed for microscopic viewing or transfer, the temperature and gas conditions were temporarily altered, and this could affect all the embryos.
More recently, "benchtop" or "sandwich" type incubators have been developed. These have individualized compartments for each patient, so that opening one does not affect the others. In addition, the culture conditions are much better than with the first incubators, as they work at low oxygen pressures, so they imitate the conditions of the human body much better. The difference between these incubators and the Embryoscope® or other types of time-lapse incubators is that they do not have a built-in camera, so if you want to monitor the development of the embryos you need to remove them from the incubator to look at them under the microscope.
