The lightweight and portable ODISsey Tissue Oximeter provides both non-invasive and real-time tissue oxygenation data. This device can help surgeons make better decisions about tissue viability during and after flap procedures. The A/C power-operated console has a lithium ion battery backup and two fiber optic sensors. The color LCD display monitor has touch screen functionality allowing for easy operation. The ODISsey Tissue Oximeter has both audible and visual alarms to monitor adjustable StO2 limits and low battery indication. It can be used with the corresponding Spot Check Sensor, designed for non-invasive real time spot measurement of StO2 intra operatively. For continuous monitoring of StO2, the console can use the Small Patch Sensors, a disposable, pre-sterilized small patch sensor with an affixation pad.