Evaluation of an Interstitial Cooling Device for Carotid Arterial Cooling Using a Tissue Equivalent Gel Phantom

In this study, we build and test a prototype of an interstitial cooling device in a tissue-equivalent gel phantom mimicking the human neck. The effectiveness of the device is measured by the capability of delivering a coolant temperature of lower than $5°C$ at the entrance of the device and the measured temperature decay along a glass tube filled with water circulating at a speed similar to that in the carotid artery. The experimental study has identified a cooling prototype design, which is capable of inducing sufficient temperature reduction along the common carotid artery. It also tests how easy to handle the device to ensure a close physical contact between the device and the glass tube. A $5°C$ coolant temperature can be delivered at the device entrance when using above $0°C$ coolant in the reservoir. The surface temperature of the device is found almost uniform. Despite its limitations, the experimental results agree generally with previous theoretical predictions. The 8 cm long and 3 cm wide device with a coolant temperature lower than $10°C$ is capable of inducing a temperature reduction of at least $2.5°C$ along the glass tube filled with water circulating at 240 ml/min. For higher water flow rates, one needs to increase the length of the device and/or lower the coolant temperature to achieve similar temperature decays along the glass tube.