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Comment by rscho | Hacker News Reader

DVT detection by ultrasound (when there is already a DVT installed) is already pretty efficient, because you don't need to know flow volume for that. We test it by the compression test, where a blood clot will prevent squashing of the vein when pressure is exerted on it with the ultrasound probe. Furthermore, the shape of veins is usually far from circular, making our method less than optimal.

Our method is geared towards vessels which have enough pressure in them to constrain them to a circular shape, namely arteries, but also (most likely) great veins. So it could actually prove useful not in DVT, but to detect one of its deadly complications: pulmonary embolus. Apart from this, knowing the flow passing through the pulmonary arteries would prove extremely useful in many cases. It would have to be tested, though. I cannot be sure that it works in this particular case.

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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.

Did they do a D-Dimer test (https://en.wikipedia.org/wiki/D-dimer)? My understanding is that this can be more reliable than ultrasound (subject to misinterpretation). I'm sure a doctor would tell you to do both if a PE/DVT is suspected.

I hope you have recovered well. My wife nearly died from medical negligence related to a DVT/PE - it can be life changing if it becomes a PE.

Actually, D-dimers alone are used in a low-probability clinical setting, because they are extremely sensitive. When you already have DVT symptoms, the standard practice is to directly go to ultrasound, which is a much more specific exam. And in case you already have PE symptoms, then most MDs would directly go for the spiral CT. http://www.aafp.org/afp/2012/1115/p913.html

Recovery is a weird word. The anxiety you face after you have one can be nearly as crippling as what you went through in the first place (this can probably be said for anything high trauma though). What I can say is that you learn a lot about blood in general after you have had one and things like Vitamin K, green food, etc. It did take 2 ultrasounds on the leg to get an OK to come off thinners, but I still feel there is a window of unknown which healthy and unhealthy people go through in the clotting of blood that is severely under treated and was a great case of where knowledge would have saved a trip to the hospital. I don't in anyway say do-it-yourself-at-home kits with ultrasound and machine learning algorithms should replace medical advice but more and more people are dying from blood clots (whether it be food related, environment, clothes(?)) that it warrants a better look - and I am up for anything non medicinal - especially ones which can cause excessive bleeding like current thinners. If I had a friend who had swollen calf muscles and pain and told them to try something at an urgent care facility to determine a clot was present and it was low cost for all parties involved ... win/win.

US > D dimer to rule in VTE, as many things can cause the latter to be elevated [1]. We almost always go straight to imaging when there's even a remote possibility of DVT.

[1] https://www.ncbi.nlm.nih.gov/m/pubmed/23948628/

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