The present invention discloses devices and methods for performing intravascular procedures without cardiac bypass. The ruggedized electronics module includes a housing supporting an electronics sub-system device. The invention relates to processes and design forms of the device enabling recording units to be designed, using simply and generally commercial components, which are able to display and measure larger objects despite a reduced field of vision imposed by the design. A ratio of the number of the refrigerant tubes to the total number of tubes of the upstream heat exchange portion is different from a ratio of the number of the refrigerant tubes to the total number of tubes of the downstream heat exchange portion. The conversion system further comprises means for controlling the switching means according to a control algorithm.