PU sensor can objectively determine which individuals have reduced superficial blood flow, and microcirculation, and are therefore at increased risk of developing pressure ulcers. With a simple examination that only takes five minutes, you get information about the risk profile regarding pressure ulcers. These can then be prevented, suffering reduced and money saved. People who lack PIV (Pressure Induced Vasolidation) run a greater risk of developing pressure ulcers and PU sensor can then provide an answer as to whether the individual has an increased risk or not. PU sensor uses analysis of microcirculation with light, the method is optical and based on photoplethysmography (PPG) where the answer comes immediately after examination and is done before the person develops pressure ulcers. PU sensor has its origins in the medical faculty and the HMV department at Linköping University.