Speaking as someone who had DVT/PE there was this stage before experiencing the PE (to the lungs) in which the calf muscle was red/swollen/cramp - it's this period of time in which case I felt like (and still feel like) a device of some type (either low cost ultrasound w/ software) could determine if a blood thinner or something else is needed - and probably save your life. It's evident that between sitting long periods (either at your desk programming or after long flights) that checking the flow is what needs to be done to prevent DVT/PE in the first place (minus other factors of course). I applaud this work because it does sound like a great effort towards something like that.