Effects of crucial parameters on the freezing delivery in the cryosurgical system

Cryosurgery has been increasingly employed as an effective and affordable therapy to treat unresectable tumors. It is generally believed that rapid freezing, slow thawing and repeating freeze–thaw cycles improve surgical outcomes. A well-controlled freeze–thaw cycle requires the adequate regulation of these key parameters in the cryosurgical system. This study investigates key parameters that potentially enhance the temperature control of the cryoprobe. In conventional systems, the inlet pressure of the cryoprobe and the flow rate can be highly unstable under certain circumstances. These could induce significant difficulties in monitoring the real-time treatment response and analyzing their impacts on the system performance. We have proposed an enhanced system that stabilizes freezing mediumʹs pressure and flow rate. With the enhanced system, the thermal impacts of critical parameters can be better processed and with greater accuracy. An orthogonal experiment analysis was also carried out to determine the optimal level of critical experimental factors. Key results showed that the cryoprobe freezing rate at the initial stage could be manipulated. In addition, the cooling medium flow rate was observed to be an influencing parameter on system performance. Results provided experimental evidence of parameters that promoted accuracy of the freezing delivery.