CARE OF YOUR PULSE OXIMETRY SENSOR CABLE When done using your Spo2 probe on a patient, don`t coil it up and store it with twisty ties. Underneath all that plastic coding are small braided copper wires that are attached to the infra red sensor. When coiling, the copper bends and conforms to the coil and pressure of the ties. Over time this will break down the copper and can possibly fray the braids or actually break them apart. This will eventually cause your sensor to have an intermittent signal or no signal at all.