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but um so exactly we'll be looking into ah a bunch of
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projects that are going on have been going on for a while now
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um some of those and i guess the things that i sort of direct across the atlantic and you are things that are happening around um
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and we'll have i think throughout the talk is split between
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are the concrete problem that sometimes the clinical domain or just or data set and somehow mandate
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um and then i try to tie this back to white should we be maybe what care about no
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p. in general not so much about clinical why should we care was to take away from the oldest is
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concern me right to use 'em right when or if i go but i
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believe a lot of problems general lies and we see them all again um
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i see ah so this is the menu for today uh all keep it very short on the background
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uh and then we'll look at two three problems so we'll look into
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predicting adverse events identical environment so when things go wrong when can we
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uh already get a look ahead on what to prepare for where things look like that might go wrong um
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we'll uh look into i doing diagnostic decisions important especially for diseases that that's great
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so where things are strange i think that look differently from the way
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they normally do a strange um and co morbidity so multiple diseases together
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ah ah strange right so so they present very differently from what the
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physicians typically and that's what they see today that's what we try out here
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um and then finally we're looking into text summarisation so how can i make long accounts for example
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long electronic health records much shorter without losing any of the critical information that a physician should get
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and how can it and and so so this is sort of the not so exciting part really exciting part i believe
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is how can i personalised it's all good what is to stop to get the difference from but for the same age
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um and and i'll uh hopefully tight is back to the journalists and what what
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sort of the take away for people that don't necessarily want to work and it's
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or um so i think that's probably small for most of you but um so i think this
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is sort of where um the work that i've been doing this intersection is not really do but um
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never mind um so i think most of our the work that
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comes although i i somewhere in the wider data signs information retrieval world
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uh in machine learning and and all sorts of sort of this is
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greater clout and somewhere between the section of the union is i guess um
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i don't know whether everyone knows what a chronic health records are what they look like or give many many overview
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uh of what you can expect from those because they are a resource that we work with a um
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so you can expect in your typical electronic health record and they're different from country to country for multiple possible
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uh what you can expect typically demographics you know age gender or uh
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who pays so this is the thing that you can typically expect so so you will know what type of insurance there half
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um you will how vital signs of the in patients right so
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you will know all um heart rates but pressures depending on how
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intensively you'll be monitored it will be a more or fewer of these um
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yeah if uh you're prescribed any medication we will no doubt um interesting we we won't know what you actually take
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um so we just know what's been prescribed which is a big problem right so we have a lot of patients that
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uh don't take commands because they already feeling better ah and sort of they they cancel on the therapies themselves
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or um and this is especially a problem in parts of the us
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uh people actually up on the way the mets right so if you on
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painkillers uh and you want to make some extra bucks on the side
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you sell this on the black market so which is again a problem um
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lab results so if we order any lab test for you and it not working all of that
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uh that will be in here the results um we may know
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gino makes or star or makes um whatever we have about you
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uh and then the the juicy part for us as an l. p. of
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this you know those days of the unstructured nodes and this is something that
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um standard data driven anything in madison often ignores right so we like to work with anything that's time series
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because that's nice easy we know the range of values to come in so text is often completely ignored or
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had simply poured into some form of topic model and then the sectors of being taken ah being worked with
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um so and i think um we often try to
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do something with this otherwise i somewhat what resource um now
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the dark side of electronic of corrected is they were never ever intended to help any person
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get better right so these things are primarily there for building we want to know what we did
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i'm not in order to but do better but in order to write you
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the correct bill and not perform any services that we don't get money for
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so that's the sad truth um and that's really the primary purpose so that means that
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uh a lot of their therapeutic too useful are kinds of bookkeeping only
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uh being done in an afterthought on being done right so i c. d. coding for example
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is a thing um so this this ontology all forty thousand i believe different codes that encode
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um sometimes that you have that in court diagnoses that encode procedures that we perform
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um and we assign all of these that apply to a patient to the record
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and then the footnote to that is if we assign goals um that pay most
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right so we know that if you have three diagnoses and one of them is
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more expensive that's the one we'll caught the others we make or we may also market
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right so there's a lot of these effects that you don't expect that first um that's that come out that
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are being introduced by the fact that uh uh that this is the billing system not the heating system um
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if we look at the the problem is so this is especially in
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us electronic health care records to have a very brief polluted list summary off
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patient has this this this and this um make sure patient takes this medication so the very the the absolute they just
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a problem this uh at least thirty percent incorrect or outdated right so um there are people so we
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found a single patients in hospital in road island to run with the cut to the finger for twenty years
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right so just because that that fact that the cup notice laceration to the finger now healed
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uh after uh probably two days after the visit was never be
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updated right so this put patients just pleading for twenty yes um
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these things grow relatively quickly so um if you're in hospital you'll oprah on average received
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two new nodes per day so if you stay for months that's sixty issue notes um
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and uh and approximately per one node per outpatient visit right so most
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people in the us have about four and a half is it's a year
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so every a you can assume forty five new nodes to come in for the average patient that's
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not chronically all right so if you see doctors at a higher frequency this will grow much quicker
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um i was seeing a bit um that i can become a big problem um interesting we
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um so for each node eighteen percent of the text in there's new the rest is copy paste
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um which again makes these things very very horrible to work with just because you have this does this
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looks like an interchange right so you have all of this this stuff um repeated and repeated in every message
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um and people right with elbows right so it's really a a vocabulary grammar
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spelling everything is very nonstandard just because it happens pretty much on the side um
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and that's sort of the the world that we're dealing with here so let's jump at
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two offers problem um this is the most time series as um problem that will look
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at the others are more natural language then take a adverse event production and this is
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especially in the intensive care unit um these things look like this so this is um
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very much what our patients look like here um and um so one interesting test is
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common interests right so for me as a lay person who doesn't know anything about medicine
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i go into these intensive care settings and i start counting
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screens more screens you have the more scrupulous patient right just
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because there are yeah no i mean that's the simple rule of thumb for for all of us that are not medical professionals
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so two screens means you in the intensive care unit congratulations you could have seen that before um
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if you have the the the more screens they roll next to your bed the bigger problem is right so um but i think
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the the the interesting take away here is you see a bunch of these curves right c. d.'s all this time series that come in
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um and these are all these concurrence signals that we measure about the patient rights when older
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blood oxygen in the brain we know heart rates but pressure is all the good stuff um
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i know the situation does that the doctors being faced with is take
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all of the stuff that comes in and a minute by minute or sometime
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second by second resolution and no reason about this patients was this patient doing
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fine on that and how will they look like an half hour right um
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so we in particular like you looked into um post
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operative patients everyone had open heart surgery in this case um
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and um and then there was in the first day or two that's a range of undesirable events that are
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likely rare but frequently enough that we can sort of quantify them
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here um so you may start bleeding again which now it's rather obvious
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um dampen it's our form of bleeding that is especially nasty just
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because you don't need to the outside but into um either your chest
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cavity or into the little back that you're hard pressed and so that's that's more dangerous just because we might not see that quickly um
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and then we have a rest and a bunch of other r. conditions um
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and right now and this was a very interesting to me so the the baseline the state of the art is very much
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a lot of training and a lot of experience right so
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out with pleading so we started out looking at bleeding at first
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so everyone after the uh the first surgery now this is idea if the patient leads this two ways of reacting to that
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you give calculation factor so you stop the my um the the the bleeding hopefully um
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or are you open the patient up again just because this is something more severe attend
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traits and you want to really see second surgery what's going on and ideally you don't
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give second surgery to people who don't need it because just that second surgery will also cause damage again
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now um the rule of thumb is unless the patient is clearly spurting blood is that
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the patient already lose a leader of blood it's all second surgery of not let's wait
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right which to me sounded rather okay i guess uh as as a decision criterion but that's what med
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school teachers you and that's what everyone does so the mission here is can we get better than that
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um when we try to do this by a tracking all these curves that we have all the time and hopefully making the right decisions
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um so what the doctors gave was was something like this so this was the markup off something that they would like to see so we
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have our eight different complications here so for example be doing what it
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sees tampa nights or whatnot and you want to see a different time horizons
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uh what's the profile of these also how likely are these complications and you may want to
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um select single ones of those in show how this is behaving over time rather
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than checking seventy ravel use all the time and making your own reasoning of this
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i just want to see a single probability of you developing a
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complication within time from x. that's that's the the mission statement yet
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um does work that was done in but then we had thirty thousand patients
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um we looked at them for twenty four hours after their initial surgery um and we
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tracked fifty a different markers here uh these
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aesthetic things such as age gender demographics um
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what type of surgery you had originally uh we have their vital signs which
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are pretty much live um we have the labs to come that come in
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add a hour by hour sometimes to allah sometimes not at all anymore
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right so whenever a doctor goals or the something it will take an
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hour to for the results to return and then suddenly we have one measurement point of well here's your red let's all control things like that
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um and then we have the the free text notes that um how both uh describing this
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actually but then also the the camp process of the nurses will document whatever they find their um
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and we have all of these um adverse events that we catch predictive
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labelled explicitly so we know when and if they actually happened for the patient
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um and i would try to turn this into production problem not the architecture that we have
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here is relatively straightforward um so we start out with our wouldn't readings on the on structured notes
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um we have a c. n. n. not goals over a a bunch of these words
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to uh give us a sentence representation and we do the same thing in another layer
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where we go over the sentences in the node and eventually uh reach
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um high notes representation items on each node we start to reasons every
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time a new textual note comes in we update all believe on the
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patient state um and and yet that's this level we have these easy um
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and z. o. all the uh the labs the vital signs all the structured information
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if we also may know about the patient right so that we just concatenate here
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um with this uh unstructured representation and this will be reasonable so no
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initially we started out just making predictions over here right so it's
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all likelihood of all come given this feature representation of this node
00:13:24
um that works reasonably well and we have all last year for that um no
00:13:29
interesting we um what really helped us um get more performance out of this was
00:13:34
to compose this original loss here um together with the
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second component what we say every node here not just
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eventually over time all the notes that i've seen but every single node here should be a good predictor
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of the overall outcomes ideally i want representations of what this does is it forces
00:13:52
or representations early on already so from the anemone says or from the subsequent notes yet
00:13:58
two already also be good predictors rather than this overall thing here being productive which which really
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uh first of all hopeless converge much more quickly um and second of all gave us i'm a
00:14:09
i'm a much better overall performance which was really interesting to see that this this kind of target application
00:14:15
i'm sort of this in the same spirit estes does joint training objectives that people look at
00:14:19
at the moment right um this this really change the game he and helped us a lot huh
00:14:26
so if we look at the numbers again i'm pretty small but let me quickly describe to you
00:14:31
um so we have for bleeding mortality indignant kidney failure i'm always done the numbers here
00:14:38
and um what you'll see is the real always a significantly better
00:14:42
than the space lines okay that's maybe that's exciting and something like this
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i'm here we draw this out all the time so blue is the um
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is the networks that uh that we built he actually this very anti r. doesn't of conclusions anymore but but the
00:14:56
recurrent neural net but the falls very much does does today
00:14:58
or approach of goat from sentence representation to notre presentation um
00:15:04
and here and right you see uh the textbook baseline so the algorithm that the task textbook says you should
00:15:09
follow right so this is this is a little plot out of the patient or not right and all the
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i'm here what we see is is quite interesting this this
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time parsed since the original surgery right and we see that
00:15:23
most of these methods learned all the time so in the beginning the patient is just doing badly you just
00:15:27
came out of a long surgery i'll of course your system is in all kinds of states of this right
00:15:31
uh and then as time passes we see that these two groups of patients
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the ones that will do fine and the ones that really need second surgery
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they will slowly start diverging rights only becomes easier and easier telling them apart
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and we see this general pattern i mean there's there's some fluctuation here and there
00:15:47
what we see this general pattern for most of them that we
00:15:49
start all out um i'm the the textbook algorithm even not even arbitrarily
00:15:54
um but all of them uh tend to get better but with the release all that margin between those um so i think what i
00:16:03
find really exciting about this uh which is more or less a
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bread and butter machine learning problem and is the fact that we actually
00:16:10
went now to the next step and prospectively deployed this so this was all retrospective for it so we had all the stale data
00:16:16
now we're at the point where we have these machines really deployed by the bedside
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um and physicians can can actually see all the likelihood of the of a bleeding over the next five hours
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is uh is is twenty percent for this patient worse is much higher for that other one
00:16:30
and this is really really interesting because now we're getting to the point we
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can actually um proactively uh try and do something about these things because often
00:16:40
um how our colleagues in the in the intensive care unit they say oh
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um these patients all look fine you have twenty of them and you alone overnight
00:16:49
um so you you spend most of your not drinking coffee and suddenly you have three people that need to be the animated right now
00:16:54
right so this is sort of what you want to avoid so you want to really make sure that if someone is likely to need a second surgery
00:17:00
which actually have an o. or perhaps that you have a team there and the surgeon who's hopefully in some state of awaken us
00:17:05
right so um which is a bit of a of a resource planning problem right so
00:17:10
um but they um they are right now using this ah and it seems to to be
00:17:14
working very well for them even to the point where we have a bunch of people that
00:17:18
we are quite confident would've made it without this thing which is uh i think to assess
00:17:23
non medical professionals helping save someone's life is something that we don't really do all that often so this
00:17:28
is really cool and i think unexciting problem that goes a bit beyond just demonstrating all we had this good
00:17:33
add forecasting does we label that doesn't really mean anything right
00:17:36
so but to really carry this over if does being good at
00:17:40
this task translate into lower mortality better patient outcomes i think that's
00:17:44
really the test of time so we can't really qualify that yet
00:17:47
um but hopefully um i would guess and a half euro so we would have seen enough
00:17:51
episodes so that we can compare standard of care with this with this new model here um
00:17:58
alright so um something very different um
00:18:04
diagnostics or especially rare disease diagnostics um i'll start with the case that we so
00:18:10
this is a work that was done in zurich at the uh university hospital there
00:18:14
and um so they had a case is an actual patient
00:18:18
yeah and the started out someone presented with stomach ache and constipation
00:18:22
not all that uncommon um but they had that for a bunch of weeks so
00:18:27
this person uh eventually went uh to the emergency room uh and uh presented with one sentence so
00:18:34
all kinds of checks were being run an inconclusive the prescribed some light medications and the person how
00:18:40
um some weeks go by sometimes the patient feels better sometimes the patient feels worse
00:18:45
um but by and large nothing goes away actually the the symptoms become stronger so we run some extra blood work
00:18:52
so we find an email so the blood cells of the tail and a bit when key and they do all kinds of funky things
00:18:57
but it's unclear why so all the usual courses for any uh are not given so we again
00:19:02
person prescribe some medication sent to spy person home
00:19:05
i'm at a a one six everything becomes worse um
00:19:10
so we checked for and you're is um in in a lot of blood vessels confined any of
00:19:15
those so we run a lot of tests send the person home with some medication so in between here
00:19:20
um the entire system of this patient start shutting down right so this person
00:19:24
who's i say the kidneys shut down so the entire system just goes into standby
00:19:29
um and and eventually and this took almost two years
00:19:32
of this person uh incurring serious and also a permanent damage
00:19:37
uh someone runs a lot of lot panel so something that you wouldn't do here so
00:19:42
uh and test will lead in the in the plot and then they found that this
00:19:45
person was twenty five times over the absolute critical threshold value off do not go there um
00:19:51
which is interesting because nobody would check for this because this person had had an office job right so there was no all
00:19:56
uh in switzerland in an office environment is to expose or too
00:20:00
heavy metals absolutely not a given right so super rec yeah um
00:20:04
and then eventually they could be treated for and that's all fine but what the doctors found out then
00:20:09
uh in the end was that this person had been importing herbal remedies from abroad so this person had imported
00:20:15
herbal medicine from indian or your basic stuff uh and this stuff was changed in that
00:20:20
because they had taken this for eight years already and the symptoms that only started now
00:20:25
um nobody made this connection but was always heavy metal poisoning so it takes a
00:20:29
while until you reach this critical concentration in your blood and suddenly you system starts offering
00:20:34
right so nobody made this connection this person the patient themselves didn't even mention that all at
00:20:40
using these we're t. slide so but they're all not prescription a
00:20:44
a great my taste medications so uh this is one of these cases
00:20:48
that um didn't go so well let's say right so this this is
00:20:52
one of the strange cases um when nobody use all the right thing
00:20:57
even though all of these hear us in terms of lead poisoning
00:21:01
just that poisoning is so rare that you wouldn't really assume that
00:21:04
right so and it's it's really if you see your position in the flu season it it hardly matters still hard look at you you'll have the flu
00:21:10
just because that's what they see day in day out right so that's that's the very rapidly so
00:21:16
no this wasn't really a disease as such because it's a poisoning but it has all the the the
00:21:22
telltale marks i guess of a of a rare disease as in it's hard
00:21:26
to spot just because it's infrequent that and therefore is this now truly rare diseases
00:21:32
um typically have some formal threshold so um i think
00:21:36
this should be the u. s. definition of a in a
00:21:40
population of fifteen hundred people no more than one half this
00:21:43
individual disease right and then you have all kinds of ah
00:21:48
so normal diseases to uh the rare and alter read diseases um
00:21:54
ah but interestingly there are many of those so we're looking at seventy eight thousand for diseases
00:22:00
and if you sum up this volume you get to something like ten percent off
00:22:05
i mean this is the us number the european numbers very some not
00:22:08
a similar right so around ten percent of the first world population have
00:22:12
a rare disease i even though individually these things are hard to spot and uh
00:22:17
and a tricky and these are rare things such as uh see like right so gluten intolerance the actual one not the
00:22:23
imagine what so people who truly suffer from from this this is often spotted very late it can cause
00:22:30
all kinds of of release of your cancer is it can uh make your bones go to mash right so
00:22:36
if you truly have celia like that's that's a really tough thing and for a long time it just looks like a very irritable stomach
00:22:42
right or ball system so there are there are a lot of these things
00:22:45
that we believe are pretty every day everyone knows someone that can't deal with student
00:22:50
um right but it's it's sort of these this is sort of
00:22:53
the level of things that we call wrestled very much nonstandard um
00:22:57
so now here um we have a this problem off lack of training data and this applies to
00:23:04
both the human physician as well as to standard machine learning right so if you think of this as a machine learning problem what you
00:23:10
would do is you would say all this one class per disease that's
00:23:13
easy that's forty thousand does approximately the number of diseases in the world
00:23:16
um and all the patients that i hate to observe with this disease go
00:23:20
into these classes on on my uh my class conditional model and i'm absolutely screwed
00:23:26
right because forty thousand diseases with a highly a skewed distribution means that in for most diseases your
00:23:31
zero training data or very little right um so there's this i'm not what we want to do
00:23:37
and then also um the same holds for the doctors who may have heard about many of these conditions in med school
00:23:43
but we don't in their daily pack to see these things right so um your
00:23:47
uh your way of treating a patient will always be a or comes raise uh what's the easiest
00:23:53
and best explanation well that's typically the very common stuff and that means that if you truly do have
00:23:58
um how rare a stranger condition i can often take you
00:24:02
months or years to find this thing so forcefully at for example
00:24:05
the number is close to two years on average that it takes people to be diagnosed with this after this into the show
00:24:11
right so you have some some severe enough that you go see a doctor and not just tough it out because say
00:24:16
but of the area um and uh and from then on we are talking ah i believe it's twenty
00:24:22
months uh so until c. d. x. actually recognised on average right and that's something that's already reasonably frequent um
00:24:30
if we look at the damage that's being caused by there is it's um
00:24:34
we're looking at around a hundred thousand us dollars
00:24:39
for patient and here in just treatment costs right so this is just treatment that goes nowhere
00:24:44
because we treat the wrong thing that we believe the patient may have um and of course um
00:24:50
if we waste time treating the want wrong thing you might actually get worse
00:24:53
and worse uh and especially for very young patients the country articulate what's going on
00:24:58
uh there's a big problems are rare diseases are involved in about a third of all first year infant mortality cases
00:25:04
um and if we generalised is to just uh and this diagnosis in general if you're really looking at
00:25:10
um tens of billions of us dollars just uh just in the in
00:25:14
the in the united states i'm gonna be in cost them that much now
00:25:19
because
00:25:20
we all thought that and there's still a bunch of studies that show that released on that machine learning will not help you
00:25:27
here right so virtually any traditional machine learning paper that you see
00:25:31
that does anything in the in the range of diagnostics will pick
00:25:35
between one and twenty diseases and we'll show you that they can
00:25:38
recognise this stuff with money for us that ninety five percent accuracy
00:25:42
that's fun but these are all of the things that the physicians already sports perfectly
00:25:46
right that's really it ahead of the distribution this is the stuff where you poor condition have tens of thousands of training data points
00:25:53
so nobody ever looks at even a hundred diseases let alone a thousand
00:25:56
body forty thousand that we actually have the real world so where you
00:26:00
would actually help the physician is where all machines really struggle so this
00:26:03
is why we turned away from from the typical um machine learning here
00:26:09
and uh and try to do this via information retrieval also try to phrase the whole thing
00:26:14
as a search problem rather than the classification problem um so uh all quickly sketch what that look
00:26:20
so we start with our first time point here so someone comes with
00:26:24
a stomach ache constipation and probably the doctor will write a bit more than
00:26:28
just this um and what we do is we use this as a query right so we take your electronic health care record at this point here
00:26:34
um we use this as a query so you need to do some filtering named entity recognition and all that good stuff
00:26:40
um but let's assume we have a good way of mining queries um from from such electronic have corrected
00:26:45
um what we do is we rank biomedical papers right so case reports study is
00:26:50
um what people describe historic patients not just in your own hospital
00:26:55
but just anywhere so so close globally published um we get this this kind of ranking
00:27:00
and um and then from newspapers you we can mine ah
00:27:03
again using information extraction things like that we can minor ranking
00:27:08
over our um over diagnoses right so we could try using just this one data point here
00:27:14
and say oh i'm stomach ache and constipation
00:27:17
they are um caused by menstrual um um
00:27:22
of menstrual pain as we had one right but um it might be that your
00:27:26
heart irritable bowel syndrome that's i read so that will be something that's right highly
00:27:29
and some weight on this list i bring two hundred or so we'll see that point something
00:27:33
because that can cause that's okay that's not helpful because nobody will scan discussed so far down
00:27:39
we also have is we know that at the next point in time someone runs a bunch of different tests gets a bunch
00:27:44
of different results here and again we can play the same game right so if you have on this form of any any idea
00:27:49
we uh can rank this and we can see that any me as course by and efficiency is uh and
00:27:55
maybe the vitamin b. deficiencies and so on so their courses what isn't somewhere during eighty
00:28:00
um will again see lead poisoning again that's not helpful because no physician has the time to read that stuff for
00:28:06
and all the interesting thing that we can do is we can fuse these results all the time so
00:28:11
the fact that um because for this and the cause
00:28:14
without and this and so on right are largely unrelated
00:28:20
but the true cause for all of these things see uh should be consistently ranked among the
00:28:25
hopefully more um was the top it's of these uh of this list that we produce yep
00:28:29
so basically if we start joining these rings and having metrics
00:28:33
such as off just sum up the rank and which you appear
00:28:37
here right so you eventually get to a ranking that hopefully
00:28:39
washes all the true diagnosis the consistent because all of the sentence
00:28:44
um whereas um all the the other stuff you uh so also to see me uh uh and whatnot
00:28:51
uh i'll be in our being punished and being being put on and that stride if
00:28:56
and this is something that interesting the works extremely well so um we uh run a
00:29:01
bunch of uh experiments here so we talk a a million and a half each puppet papers
00:29:06
we uh i took twenty two case reports off particularly hard problem so these are not the people who
00:29:12
in flu season come with actually if you end up being diagnosed with the flu or not being sent home
00:29:16
so these are uh i had big cases where our uh our collaborators at uh the only spit out indirect
00:29:22
said oh this is hard these were apart knots that we that we root around with for a bunch
00:29:27
of mons and these are tough to cage uh and ends typically it's it's because the condition is rare
00:29:32
um because the great patient is a bit strange all because they have multiple things and
00:29:36
you often have combinations of multiple diseases that just to get a look like nothing else um
00:29:41
so all i do studies twenty two cases that we started out with um
00:29:45
yeah a different diseases in here so some of them are actual multiple times
00:29:49
um and we have three two nine episodes of electronic health care records steps in time
00:29:54
um for each of these ah i'm ah i'm weak compared this this this ranking quality now uh our
00:30:00
baseline is just a patient text classifier right so if you work to approach this in a very standard
00:30:06
um machine learning way you would say okay that's one model per disease um and now you look
00:30:11
at the posterior probability of having generated out patient on the the model of that it's it's right um
00:30:17
and you'll just count as as a um as an and one model
00:30:21
of right so and the thing with the uh with the highest probability
00:30:24
of having generated that patient will be ranked highest and so on and
00:30:27
instead of just doing classification we really rank so both methods give us ranking
00:30:31
so he wrecked by the posterior uh and the other case we rank by um what i'll retrieval model gives us um
00:30:39
and then everything that mentions a particular disease goes into this thing
00:30:43
now um does one interesting parameter and this and this is this is what we call a capsule be this is the kind of what
00:30:50
do we consider a diagnosis right so how many diseases are you willing to uh
00:30:54
to uh to diagnose and we'll see on the next slide ah how this behaves um
00:31:01
so he uh our performance metrics m. r. r. which is basically one
00:31:04
over the ragged which you recognise the correct diagnosis so if you have
00:31:07
a trend one it's one and otherwise it goes to point five one
00:31:11
third and so on right so higher is better expounded in zero one um
00:31:17
now if we half hour triple approach here we get to score off close to point five so
00:31:22
meaning you are on average joe correct diagnosis will be in the top two on result trying to
00:31:27
um which is useful right so this is not a drink eighty anymore nobody needs a scroll you look at this list
00:31:33
and you test for a bunch of things and on average you will have found um what's going on here
00:31:37
now let's look at the next page in a method here and here in brackets i show you how many
00:31:42
uh most frequent diseases uh we're looking at right so the things which we have most data
00:31:47
and we always make sure that the eight diseases that are truly the ground
00:31:50
truth i artificially injected you're right so here we have twelve run those plus
00:31:54
i'm helpless the eight diseases that actually the target which we sort of help this model to cheat a
00:31:59
bit um and here we're looking at as we make
00:32:03
this problem more realistic what happens you're really right um
00:32:08
so if we're willing to recognise a hundred or even two hundred fifty diseases uh something like this
00:32:13
um which is sort of we're all machine only papers and um then we get to know and the and the
00:32:19
top four five francs of the result list you still see
00:32:22
your diagnosis but these all not the the the rest stuff
00:32:25
so had we not injected artificially these super rare conditions in here in these and and these groups you
00:32:32
uh these things would never found that if you make the problem more realistic if you're willing to say
00:32:36
okay out of forty thousand diseases that they're on the world we're willing to consider the top one thousand
00:32:42
then already you're looking at a result list of light and fifty right and that's already arguable whether that's
00:32:47
still useful for position test for fifty different diseases really
00:32:51
do the deaf or differential diagnosis for fifty different diseases
00:32:54
that's something where way we're not entirely sure whether physicians will actually have
00:32:58
the time and the patience just all right and and that you would have
00:33:01
to look at forty k. actually in order to properly this whereas basting here
00:33:05
just does matching right so we have in this retrieval approach we never have
00:33:10
class conditional models so we never go up and say oh congestive heart failure has this following model we
00:33:15
only do matching rights if you your description is similar to pass patients descriptions we links you to each other
00:33:21
right so which i believe he uh gives it was really an edge on these things and it would also mean that
00:33:27
as soon as a new diseases recognise we're and principal able to um um to recognise
00:33:33
it as soon as as being published on right where is here you would have to
00:33:36
update your model and it would have been ah i class conditional model with the single
00:33:40
training data point which again is probably not the most abbas thing in the world um
00:33:46
and here we played around a bit with what happens if you change the collection size that you're half
00:33:53
um so this uh this number of million articles that we uh uh that we're using in a belief
00:33:58
we have a hundred random stations of drawing these um except for you because is or anti data set
00:34:05
and um and we can see that there's does does quasi linear a relationship between
00:34:10
more articles mean you have a better chance of having observed the patient that behave
00:34:15
similarly we ugly to your stride so the more evidence you have
00:34:18
the the great it's your chance of actually catching um the true diagnosis
00:34:24
right um so this was really interesting and this is something that we are um
00:34:29
still doing together with ins of the talent bar and and with the university hospital in zurich and a bunch of others
00:34:34
um where we're trying to bring this not now really out to the patient right so which again
00:34:39
this this step uh experiments done paper written a a great paper being side it that's all fun and games
00:34:45
but i think that would the real differences being made once you once you try and bring it to
00:34:49
the patient which is hard because that means you have to build actual systems that are robust enough to
00:34:54
take millions of requests ideally and and whatnot so this is sort of the challenge that we're facing up and this um
00:35:03
okay so the final and this is um very early stage
00:35:06
ongoing work so this is not yet published but i'm i'm super
00:35:09
excited about this and that's why i wanted to tell you a bit about it is uh this idea of personalised text summarisation
00:35:16
so i'll very quickly tied back to early so uh u. h. r.
00:35:20
s. uh grow fast right so two notes per day one up a visit
00:35:24
depending on what you have if you elderly or chronically ill you'll see your physicians
00:35:28
a lot more often you have accumulated a lot more most often some more big stuff
00:35:33
um uh and therefore you will just have ah
00:35:36
more that bills that i need attention right so especially
00:35:40
for ah loyal customers as we call them right so people that don't move around much so you
00:35:45
live uh and and see the same g. p. for thirty years they have a huge record a new
00:35:50
uh if you're very all your record also grows very quickly right so so these are very long documents now
00:35:57
interesting lee and these numbers are from the us i don't exactly know how
00:36:00
that translates into your but i would assume it's not much better here um
00:36:05
so your physician will spend about twice as much time
00:36:09
with documenting what they see on you then they spend see
00:36:14
which isn't really great right so for every five minutes uh actually doing
00:36:19
stuff with you they take ten minutes writing on what they saw um
00:36:24
so a lot of this is not being budgeted for in the time
00:36:28
allotment that a physician has with you so that means a lot of that
00:36:31
happens i'm at home or maybe not well see um so this whole
00:36:37
record keeping is is very problematic at the moment so a lot of people
00:36:41
uh work with the use a text synthesisers also speech to
00:36:45
text kind of engines to try and get this this uh
00:36:48
this uh scribe process out of the way but still at
00:36:51
the moment um a lot of physicians especially primary care physicians are
00:36:55
i'm very frustrated but it's process not translates potentially into medical error rights if
00:37:00
this constantly is something that you do in a bunch of hours at night
00:37:04
maybe you're tired or maybe or frustrated enough to ah to overlook things uh
00:37:08
i similarly um it's pretty proven that this leads to burn out among physicians
00:37:12
especially primary care physicians ever pretty high rate of just going out and doing
00:37:17
other stuff uh i'm going in for a nice cushy from a job instead um
00:37:22
okay so i'll we're going to try here is can we use automatic
00:37:26
summarisation for this right so the idea being you have this long health record
00:37:30
you want to uh give the position an automatic summary that's
00:37:33
hopefully up to date as all the important information doesn't miss anything
00:37:37
ah and it's ideally much much shorter right so binds like less of that time um in preparing for the next
00:37:43
is it's a reading up what's this patient again what happened to them since i last saw them and so on um
00:37:51
very quick recap on on the market magic summarisation comes into fundamental flavours
00:37:55
um the old fashioned one is extract of summarisation uh that's very much like writing
00:38:00
that run some letters back then right so you look at uh all your original material
00:38:05
uh and because generating language uh prior to twenty thirteen was really hard so what
00:38:10
we do instead is we look for language that humans wrote so that's probably grammatical
00:38:14
um which will take phrases or sentences out of theirs and paste this into our
00:38:19
summary right so um and that's really just you it's very much information retrieval based
00:38:24
so you have some form of query ah and you go for all
00:38:28
the juicy facts uh about the patient and you place them in here
00:38:31
and since that human wrote that for you you never really have to
00:38:34
start generate having the machine to learn how to rights as human language
00:38:39
um and then the uh the the somewhat more popular approach at the moment is abstract of summarisation where the ideas much
00:38:44
like a person would reach the text or the event or whatever you have so you read all the available information and
00:38:50
then you go way you think about this and you're right i hopefully well formed summary that and someone reads right so
00:38:56
you really get into the business of generating language so this is um a framework that is from twenty fifteen i believe um
00:39:04
and what this does is you have your um your original sentence here so this is the long text
00:39:09
uh that's the summary that you're generating one word at the time um q. encode these uh these
00:39:15
words yes we have typically some form of of recurrent neural network i given attention distribution across it
00:39:21
that's being informed by what have we already generated right so i know
00:39:25
what i've already written about and where i am now in the generation process
00:39:28
um i know this gives me this this context vector here from which i then
00:39:33
sample um he just does what distribution right end up with uh tell me that
00:39:37
of the sentence start in germany i would want to say that they teach someone and then i'll see that
00:39:42
there is such a argentina in the two zero when and whatever going right
00:39:46
so very much this is the the basic architecture notices a bunch of problems
00:39:50
um so the next iterative step was um to do this pointer generator
00:39:55
um and this is the ability to basically say you sometimes want to copy
00:40:00
you largely want to generate text but once in a while you want to copy text and is mainly
00:40:03
due to all the vocabulary problems so this guy he requires that they be word embedding fall token see uh
00:40:11
well who works in neural that much language processing knows that we always have
00:40:15
to constrain our vocabulary because otherwise it doesn't fit into our jeep use memories so
00:40:20
the vocabulary sizes the first thing to to die right so
00:40:23
things like two zero is likely to not have a word embedding
00:40:28
alright so um and we would be able to generate this token here right so this architecture here no gives
00:40:33
us the ability to say oh yeah i want to uh generate as we did start germany beat whatever right
00:40:40
um i have all of this but then we have this p. jen here in dispute genesis which if that
00:40:44
says okay there's some probability with which you want to
00:40:48
um indeed sample from this distribution here generate any word
00:40:51
and then there's the the complement of that which says maybe you just want to copy a token for me
00:40:58
right and this is the nice thing because that's as so even though this thing here
00:41:02
will end up being some unknown word right so that i don't have a proper embedding for
00:41:07
i may be able to say off actually now the best option here to take a is
00:41:12
ah maybe a a sample or copied is on all worked right so i'm just just cost me
00:41:18
um and is ah has really revolutionise both machine translation and
00:41:23
uh and summarisation which are very similar so whether you translate
00:41:27
from english to georgia english or from english to friends uh i'm french turns out to be um
00:41:34
a very similar tasks also i think since all these these neural architectures out there
00:41:39
a machine translation and summarisation work much in the same way um which is quite interesting um
00:41:47
one big problem that many of these architectures how far repetitions
00:41:51
so many of these models lose themselves in repetitive uh repetitive clauses
00:41:56
and then and then and then and then and hopefully that's not well the third eventually but it really doesn't
00:42:01
uh isn't the best use of the of your vocabulary and of your of your space that you have here
00:42:06
so a lot of the sequence to sequence models have have that kind of problem
00:42:10
um coverage is a different thing that was um proposed for some of these models
00:42:15
which basically says in your attention layer so in in this guy here
00:42:18
right um you want to make sure that every german every phrase get some
00:42:24
uh accounted for amount of attention right so if you've already i tended
00:42:28
to this word are not right which is this some here over this twenty
00:42:33
i'm i'm probably i don't want to draw from that again and generate that again right so and that basically
00:42:38
uh we can use that even the attention they answer all because in the last few turns i've already sample from this
00:42:43
word and i don't want to do that again um or i can do this in the last function what you say
00:42:49
overall i would discourage summaries that are highly repetitive just because
00:42:54
they pay too much attention to the same tokens all the time
00:42:57
i i'm not actually lose too much more natural appearing um summaries and we'll see
00:43:02
in a bit that we're not quite there yet um but that is a really helps
00:43:08
okay um i'll gloss over this in a bit so the idea is that
00:43:13
physicians are different and they want to know different things about the patient right so
00:43:16
think about your cardiologist and your eye doctor they probably have very different questions to
00:43:20
watch you uh and you the idea on the page for this whole thing is
00:43:24
um why don't we summarise the personalised manner um unfortunately that's not something we
00:43:29
can do with state of the art that's right so they say fuses source
00:43:34
generate something and if that overlaps highly with uh with the target well that's good right um
00:43:40
so what we try to play around with our our topic models
00:43:43
right so we try to estimate topic distributions for these original text
00:43:47
and then to use this distribution in making the summary right
00:43:51
and now i can fiddle with it so i can say oh
00:43:54
actually painless this topic because i don't care so much about this or um altogether remove that
00:44:00
and if you think about the general news domain right so if you think about your news analyst
00:44:04
they want to read up about certain developments and they might be the expert for the asian market and they don't really care about developments
00:44:10
in europe on this it has immediate consequences on ages so summarise this
00:44:14
thing but really penal lies to europe angle on this and focus on
00:44:19
right and we are able to do this and also now we have a vehicle that says i'll have all these these little levers and i can say or
00:44:25
give me more that less of that while still making about that summary of this so this is the the basic idea um
00:44:31
this again is small uh and all just very quickly give you this idea
00:44:35
off now we have this topic distribution right so modest attention all the terms
00:44:39
um but also this original topic distribution are we can now enforce that is summary
00:44:46
match either the identical topic distributions so make sure you are very similar
00:44:51
in distribution of attention that you give to certain topics not there's individual words
00:44:55
or i can as i said fiddle with this enforce certain different distribution on this whole thing right and it's basically
00:45:01
goes into account expect tricky of um and this is then the thing that we either sample from what we copy from its original thing so
00:45:07
very much same basic idea just this topic component gives us a slightly
00:45:12
obstruct few on on the on the language that's being used to um
00:45:18
so the h. o. stuff is still in the running but we do have results on new summarisation sold somewhat
00:45:23
different domain exactly same architecture so i'll show you a bit of this and has some promising early results um
00:45:30
so this is the typical if you do summarisation this is the data set that most people use so this is news stories from c. n. n. the daily mail
00:45:37
um we have somewhat shy of three hundred thousand articles and summaries for them
00:45:42
um articles are typically around eight hundred words long summaries
00:45:47
of the reference summaries around sixty so they're pretty short
00:45:51
and um this is our nice little due diligence comparisons of these two here out
00:45:56
what we propose and they're doing pretty fine in comparison with uh with the baselines now
00:46:03
let's um look into one big problem again repetition right so we do news coverage and
00:46:11
still we saw that all this to still all in in all these baselines with coverage mechanisms
00:46:16
uh there's still this problem of them repeating themselves so uh we tracked is now so what
00:46:21
you see here is the percentage of enron so you're the grounds bigram trigrams and so on
00:46:26
being repeated using the vanilla point to generate a blue
00:46:30
pointed generator with coverage which is sort of the baseline
00:46:33
uh our method negatively and then in red uh all method here with this coverage and
00:46:38
if we look at you know grounds there's not really much of a difference just because sometimes these words you
00:46:42
need to you reuse right so the this these are really atoms of the message that you want to send
00:46:46
i you'll have to use them now but already as we look at bigram see you can
00:46:50
see that as we use um the coverage mechanism
00:46:54
on top of topics now we can really avoid
00:46:57
a repeating all cells so much just because we don't know the topics gives us this vehicle that say oh
00:47:03
yeah you you do want to pay attention to this topic here
00:47:06
but since you've used those identical words before out make sure you use
00:47:10
synonyms all the things right so and this is really interesting i'm
00:47:13
here in this in this uh uh context i guess what you get
00:47:17
much more natural appearing so if you look at the extent of these bars
00:47:20
so twenty not fifteen percent of all six problems with a pretty long sequences
00:47:25
uh being repeated but virtually all of these methods here how where versus this guy was probably at that
00:47:30
to what three percent party of um which is much much nicer in terms of the summaries that you get
00:47:36
okay so i promised you personalisation but didn't do personalisation so far right so i only said
00:47:42
the distribution of topics that you see in the source um and now we played around with this as well so our first example
00:47:48
here and i'll send you the slide so that you can actually read this uh at home because there's maybe but a small um
00:47:54
but what we did here was um this is the reference summary um this is often
00:48:00
the uh summary offered and now what happens if we take out anything related to health care
00:48:06
out of the story right so um we have a person with a nice murdering a
00:48:10
patient in a in a hospital um and then and then there's a poisoning k. is right
00:48:16
um and of vanilla summary here we'll talk about hospitals
00:48:20
entails a and nurses and whatsoever and here we still correctly
00:48:25
describe out what's going on but we don't use these words
00:48:28
sorry right so we talk about a person murdering uh that that's a poisoning other people
00:48:33
um but without really describing the hospital angle to this right so and these are really
00:48:38
very early results of this actually working out quite nicely rights and you can imagine that there are some use cases for this
00:48:44
um in the age all the main uh we're not quite there yet just because summarisation is at the top for their um
00:48:50
but um so that's sort of what we're doing okay let me quickly in the interest of time also do a
00:48:56
very quick ah gloss over or why should we care if
00:49:00
we don't work clinically white was this even interesting or um
00:49:05
representation burning i believe um as a a hot topic
00:49:09
right now and everyone's doing it in some form of that
00:49:12
um and that's pretty easy right i mean just pouring anything into birds and believing that that's the new
00:49:18
uh new truth right or excel net or whatever your favourite term transformers at the moment ah that's pretty easy
00:49:24
but ah learning meaning for representations as much tougher right so
00:49:28
do these things really represent anything that corresponds with human intuition
00:49:32
right um this is broken latex formatting but uh so think of explained ability
00:49:39
right so if i go into the whole business of explaining why a i
00:49:44
predict a certain class label right then it would be really nice if the atoms
00:49:48
of the message on which i'm predicting so the word and readings all the way
00:49:51
to begin if they do mean anything to people right so if they're really um
00:49:56
choose we had a a co occurrence um generated vectors that's difficult um
00:50:03
and uh and we saw this for example in the adverse event production case right where um
00:50:09
tools such as last functions that force representations to be expressive already right so not
00:50:14
just tools but eventually in some really complicated machinery of being used but really forcing
00:50:20
the the meaningful miss all the way into the the and on all the bearings for example is useful
00:50:25
a lot of people use these joint training objectives where you could train on for five tossed right
00:50:30
to just make sure that you don't over fit too much to your problem at hand and
00:50:34
often you get a lot of good results from that and same for transfer learning so not just
00:50:39
uh if you don't have enough data but also really if you want to make sure that what you learned there
00:50:44
corresponds somewhat to to a general meaning uh i think is very important
00:50:49
um hi all the problems a rare events that's
00:50:52
that's probably my my favourite a problem at the moment
00:50:57
so i think machine learning is really great opposites catch right so ten thousand images of each
00:51:01
clause and you'll get fantastically autistic be good at this um but does that really mean anything so
00:51:07
what happens if the number of classes and the number of data points per
00:51:11
clause uh if not grows or excuse right so and that's that's a big problem
00:51:16
so there's a lot of really really exciting stuff happening in the
00:51:19
whole one shot zero shot learning community right so what if i
00:51:23
if you only a single training example polka so maybe you've never seen an example right so i only tell you this is
00:51:29
all the class now predict that thing but you have don't know training data um so there's super exciting stuff here and i
00:51:35
um so we saw a bit of that on the whole rare disease diagnostics um example
00:51:41
and i firmly believe that uh things that work in this retrieval style and if you look at most of the
00:51:46
of the more than zero should learning algorithms to all retrieval and so on some point rather right because you always say
00:51:52
all project these things into space and then look for neighbours or the uh look for gradients that you can actually generalised between them
00:51:58
so so very interesting that we actually build a search engine here uh in the
00:52:02
middle of all machine running approach with this um and then finally uh i think here
00:52:08
with a lot of text generation both for a summarisation for machine translation
00:52:13
we really don't have the reader angle in there at all right so there's hardly anyone who cares
00:52:18
for the person who actually consume the stuff that you generate so we just say oh there's use keyword overlap
00:52:23
uh and the more about the better and the links should somewhat somewhat
00:52:27
work right so if you look at your blue scores and all these other
00:52:30
metrics for um generated text quality this there's never anything about the reader and
00:52:35
uh sometimes you have something like reading level but that's sort of it um
00:52:41
on the other hand you a few months to write texts and ideally if you
00:52:45
they do this well they have a very clear idea who will read this thing
00:52:48
what they already know and what they want to know from this text right so very very different picture not just
00:52:53
all we text generation engines that are pretty good hopefully but we also care about the readership so i think this
00:53:00
uh in general so for a bunch of these tasks like in our
00:53:04
new summarisation or your jaw summarisation idea here ah is going to be
00:53:09
very key in the next few years to look at user models or
00:53:12
at least audience models also groups of users the to get a half
00:53:15
similar uh um requirements and needs towards the text that you're generating there
00:53:20
okay i'm just too too close here so we look at three clinical problems
00:53:25
um i i hope with some properties that we see real career in many
00:53:29
many other a domain so that we're not just sort of uh solving certain
00:53:33
um technical tasks but really also i'll hopefully addressing
00:53:37
interesting an l. p. or i i problems um
00:53:41
and as the closing thought i i would think that there's so much enthusiasm about precision madison
00:53:46
but i'm actually physicians are really good at this already so we train them for precision and
00:53:50
they're they're they're really strong at this now recall the something that humans are not built for
00:53:55
right so considering seventy signals concurrently at second resolution nobody can do that
00:54:01
uh really quickly going and read a million medical articles and going
00:54:04
back to the patient and telling them what's going on people also
00:54:07
come to that so uh i would strongly advocate for something like
00:54:11
recall medicine right so we have the machinery how all precision schumann brain
00:54:16
uh on the recall part and say well look here's all the information that you want to
00:54:19
have now go into you shouldn't thing right so i think that's going to be really important um
00:54:25
so as an interesting fact here's also bunch of years ago off um people attribute to medical error on
00:54:32
soul decision making going wrong somewhere in the clinical pipeline right so leading to either the wrong diagnosis or treatment
00:54:37
um as the third leading cause of that right so that means you have cancer and you of congestive heart failure
00:54:43
uh and then before you have traffic before your gun violence before you have
00:54:47
all these other good things um you half megahertz right so if we can
00:54:51
use some of the uh the machinery that we all work on a to chip away on
00:54:56
this huge budget i think that may make much
00:54:59
bigger impact then um then that's holding individual diseases

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Conference Program

Clinical Natural Language Processing
Carsten Eickhoff, Assistant professor of medical and computer science at Brown University
Aug. 20, 2019 · 11:05 a.m.
299 views
Clinical Natural Language Processing Q&A
Carsten Eickhoff, Assistant professor of medical and computer science at Brown University
Aug. 20, 2019 · noon
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