CoVAS is a hardware accessory for use with the PATHWAY Models ATS systems. CoVAS offers computerized, real-time, continuous VAS evaluation – adding an important dimension to pain threshold measurements. It can be used for continuous monitoring of response during therapeutic and experimental sessions, as well as measuring outcomes in pharmacological drug trials. A patient-controlled potentiometer, or slider, is utilized and the thermal stimulation and patient response curves are synchronized and available for export to a variety of spreadsheet programs for analysis. CoVAS is also available in a special non-magnetic version for use in an fMRI environment. The hardware is modified to work inside the MRI exam room, connected via a long cable to the stimulator, located outside of the MRI room.