Limited beside my pleasure to introduce. Our similar speaker today Professor Tim Farley from years. In assistant professor. Guard unit from. Washington. And frankly one of the things that is actually very well known for is the motion of. Clinician and they're doing a procedure. Should not use or you know a lot of today. You also commercialized the work. Or wanted to. Do this he said. Today we're going to hear from. Surgeries surgeons mistakes. That are. So. Wonderful. Thank you so much data for the invitation it's been wonderful to actually see your campus and see the amazing projects you guys are working on here and fellow roboticist today and clinicians yesterday. So before I begin I just want to say two things have a little disclosure one is you'll see some information from C.S.S. incorporated we created a company in this area so there's a financial concept of interest there and the other thing is you might see so this is a talk about surgical robotics so you'll see some footage of surgery and whenever you see that little element show up. I learned my lesson to always do this whenever you see this little symbol that means the next slide is going to have some footage of surgery and so about maybe less than ten percent of the population they get queasy when they see footage of basically blood and guts and that's you if you see that sign just look down check your email do something else. I learned my lesson because once I gave a talk to a math department and they all got really queasy and not good news. All right so let's dive in with a little bit of history about surgery so I really think the field of surgery began as a scientific discipline with John Hunter who for the first time started using the scientific method in surgery and that's really where it took off this is back in the day when for you to be a surgeon the idea is you were a maverick you actually created part part of your surgical training was how to create all of your own tools you make all of your own prototypes and everything you put into a patient was stuff that you made yourself. The application of the scientific method give a rise of proliferation of progress and surgery with the rise of anesthesia finally some people really think surgery really only started once and if he was getting used it was only in the eight hundred fifty S. as the advice did his work scientifically proving that surgeons should wash their hands to avoid spreading infection and he was actually met with a lot of ridicule at the time people thought it was. A useless idea but scientific evidence won out this is before germ theory and things really picked up and then ultimately. The way surgery was trained is still the way we do it today you have to go to medical school you get a medical degree an M.D. and then if you want to be a surgeon you go into residency for maybe four or five more years maybe ten if you're doing neurosurgery and it looks kind of like this you have an attending surgeon looking over you you're doing a task maybe for the first time and he lets you do it and or she might let you do it until you make a mistake and the idea is you see one being done you do one until you make mistakes and then you start teaching them and it's called the house stayed in model as it really is remained largely unchanged until the last decade or so because the field of surgery has been changing this historical perspective where you had open surgery where the surgeon was directly interfacing with the patient in open surgery the connection is one to one you see in the left half picture in the one nine hundred eighty S. surgeons started working with engineers to. New tools you can see these long slender tools here called laparoscopic tools the surgeon got further removed from the patient but this is a major benefit to patients instead of going. Having an open procedure for let's say a removal of an appendix you have to stay in the hospital for a few days afterwards last topically you can go home within an hour because it's so minimally invasive. And then fast forward to today where the Davinci surgical robot you can see the geometric almost exponential rate of adoption. Of this technology where the surgeon is actually completely removed from the patient they can actually be transcontinental removed across an ocean and doing these procedures it's been done before. This sort of geometric rise was actually due to your so today we haven't actually seen this penetration of robotics and cardiovascular supervised bascule are much much larger markets much bigger opportunities but notice was going on not only have you now removed the surgeon even further from the patient there's no force feedback. There might be in different rooms something else is also crept in that traditional interface has been replaced by a digital interface so everything going from the master console is fiber optic digital signals about one hundred twenty eight dimensions of data running in real time. And so sometimes you don't even need a patient so increasingly what's happening is surgeons are training in virtual reality or in simulators so you may make your mistakes they are sort of on humans and get your skills quantified before you actually go on a human being what you see here is some work on a virtual trainer or this is just having real surgical tools doing a mock trial of task and measuring your skill. So the words are it's no longer blood and guts it's bits and bytes it's a classic quote from one of the sort of godfathers of modern surgical robotics and that's really the feel of computational surgery which is really exciting because for the first time the field of surgery is now rigorously quantitative or it can be and we can use methods from machine learning from Systems Engineering Systems Science. To grapple with problems in health care longstanding problem with health care so it's an exciting field because it's. Potentially going to do some great things in the field of surgery so let's look at some problems facing health care like what kind of stuff can we potentially help with so in the turn of the millennium this publication came out landmark public publication from the Institute of Medicine where the field of medicine of health care as a whole took a really cold hard look at itself using numbers and not opinions what they found was that the rate of I after Genesis that is human error preventable human error was rampant and those medical errors led to approximately one hundred thousand deaths a year preventable medical errors and about thirty billion dollars of annual costs. But a third of that was surgery even though surgery is nowhere near a third of health care but they are responsible for a significant portion of those errors consider that the average American has seven thirty in their lifetime this is a risk that we're all kind of exposed to. Consider also that well I'll back up in a second when this came out this was somewhat earth shattering because nobody really expected these numbers were so high so there are a major policy shift in health care things like the wait list The Checklist Manifesto came out where surgeons learn from pilots that one of the best things that pilots have done to avoid trouble and landing and takeoff is they'll just go through checklists and they started incorporating that but despite all these massive shift in policy changes. These error rates kept creeping up they kept being publications that would come out that actually show the numbers keep increasing and people would discredit those publications because they weren't publishing very reputable sources until last summer. The British Medical Journal a very reputable source dropped this bombshell that in fact medical errors were so grossly under reported that they're actually one computer correctly they account for roughly the third leading cause of death in the United States just phenomenal which means that medical errors are rampant we're talking about you know a surgeon taking out the wrong kidney a nurse giving the wrong dose of. Pharmacist prescribing the incorrect medication or passing out the incorrect medication. This is a pretty serious problem and healthcare has been trying to grapple with this problem for millennia the fact that human error it's rampant and surgery especially is very difficult little in medicine so let's dive in. Caution there's going to be some footage. In two thousand and thirteen Burke Meier and his colleagues writing in The New England Journal of Medicine hypothesized that if you measure the technical skills of a surgeon you would correlate directly to patient outcomes shown here is footage from two of the surgeons in his twenty baryonic surgery study these are practicing surgeons this is their full time job their. Procedure and he asked that they voluntarily take one video of their surgery and submit it to their peers for and on of my assessment of their technical skills. So you can decide who you'd prefer to do your surgery this is a top and bottom quartile performer. What they found was that as a technical skill rating increased along this axis the risk adjusted complication rate decreased so much so that if you were in the bottom quartal of performers you had a five fold increase in death a three fold increase in blood loss and a three fold increase in hospital hospital stay nobody anticipated that technical skills would matter that much and again this is for practicing surgeon this is not trainees is not residence. And again that was from one video IT project outcomes surgical outcomes of that surgeon's entire year of practice which is pretty interesting so how hard can this problem be measuring technical skill I want to show you two surgeons these are actually residents but they are doing surgery and I want to ask you as quickly as you can to tell me who you would prefer to do your surgery. Anybody want the person on the right it's a notice you don't have to wait ten minutes it takes this person actually finish this task to tell within seconds you can tell you don't need a medical degree to tell that one of these individuals looks more skilled than the other interesting well if can we quantify that can we can we do something a little more rigorous and scientific instead of just a gut feeling. So the video that you just saw we're actually capturing the two motion for the surgical tools is what they look at plotted out in time you can see a lot more sort of entropy and chaos than one versus the other but this is still pretty qualitative this is still not a not actual number. And you can look at things like the force profile of grasping so on the top here you have the left and right hand grasping of and somebody we called an expert will get to that and it's not that the expert has less force or more force than the novice It seems that they have a lot more consistent force behavior and the novice just has a lot of variability. So anyway these are sort of nice observations but they tend not to scale very well to let's say looking at one hundred surgeons maybe comparing two very extreme cases we need to do something a little bit more rigorous. And so for this we collected some massive databases there called Blues and Red Dragon Age I won't get into those details but we have over fifty hours of these procedures recorded where we have to emotion and video and the idea is can we quantitatively measure the skill and do better than a stopwatch So it turns out that measuring how long it takes somebody to do a task as very hard to compete with a good surgeon can do stuff more quickly period and if our skill metric our machine learning amazing skill metric gives you nothing better than the correlation to a stopwatch it's useless you can get a stopwatch for ten bucks and you're done and so what we try to do is have a quantitative measure of skill that's better than a stopwatch So in ten seconds can you tell me how good skill is just like you guys could and that's been kind of under explored and so a little bit of footage coming up so what you see here is our early work a machine learning. This is just a hit or Marcus model. Being trained in real time on the on the live survey that you see running here. Evaluating in real time pre-trained on the surgery that you see here and this allowed us to actually quantify the skill of the surgeon. I won't get too detailed into the method it's just pretty much boilerplate hit a mark off models. And I apply this in my Ph D. work and I was actually disappointed because it didn't work very well. Like yes you could do surgeons but when you take the first ten or twenty or thirty seconds it actually work and I'm really confused I was like well why would that be so I started questioning the assumptions that the surgeons gave us they told us who the experts were they said hey these guys are the best in our department this guy is the maverick use him and I trusted them I said OK I'll use this as my ground truth labeling and I start to get really suspicious of that so what I did is I took fifty six of the videos. I took with what they use as a gold standard so this is an example of a tool called that subjective structured assessment technical skills is just a set of Likert scale domains so want to kill of want to five How well do you use both hands on a scale of one to five with your tool motion efficiency how confident are you that kind of stuff and this has been validated in the surgical literature this is a tool that they that actually faculty surgeons will use to evaluate their residence before they accredited. Anyway I sat down my surgeons by collaborating surgeons and I put in front of them fifty six videos and I asked them to evaluate these surgeons as if they were evaluating their own students to be as objective as possible. What I didn't tell them is that the fifty six videos are looking at videos of all the people they told me with a top experts and they proceeded to disqualify over half as non competent surgeons It was interesting. I do I first I was kind of shocked I didn't really know what to do with that. He would define competence so you had to have both a score above three. So the average score for motion quality and about three for by Man U. ality and there were very few that actually ended up in both. So we were suspicious of those results but when we finally used a true sort of ground truth that wasn't noisy then the skill evaluation really really worked so the machine learning problem is very ill posed if you have two sets of data that are very noisy So let's say you have labeled data and you sort of cross contaminate a bunch of those labels any machine learning algorithm is not going to work very well. So when we got a better ground truth it worked and we could actually identify skill with and I think it took forty seconds to disambiguate novice from X. or behavior for a task in the cool thing was at least for these three training tasks and these three tasks by the way. Are correlated with surgical outcomes sort of performance. The cool thing is it's a good market model so we can crunch this in real time so for every frame every ten milliseconds or so every five milliseconds you can ask are you doing good surgery or poor surgery how well do you fit the model so what you're seeing here is a probability that you're acting like an expert versus the probably really that you're acting like a novice on that extra video that you saw and what happens is sometimes you're looking like an expert sometimes the model doesn't know sometimes it's confident that both of them are doing the same thing so you can't really use that information and then sometimes it inverts sometimes a person starts acting like a novice and this is the other problem with the ground ground truth data is that for an hour of surgery from an expert for about ten seconds he'll slip up and do something very good that's going to pollute your ground truth labels and a novice like for three seconds they can get lucky and just look awesome for three seconds and that again pollutes the data so where this fall and we end up coming up with a thing called the minimally acceptable classification criterion so one is you have to provide something over test Times got to be better of a test I'm well great we can get real time metrics this I will get into we published recently that it takes about ten to fifteen seconds. Of data from the beginning of machine learning will give you everything you need in the ten to fifteen seconds it's not going to give you much more improvement to on the entire task and that he was a harder one we said that. Machine learning will fail unless you meet this criteria and if I show you guys an obvious novice somebody that should not be touching a patient versus an obvious expert you will unanimously agree that these are extremes of a category right. And so our minimally acceptable criterion was that a machine learning algorithm has to be able to give you that hundred percent accuracy and that no brainer case and we found is that every single machine learning algorithm technique that we've employed or our colleagues competitors in the field have employed has failed to meet that which is interesting. Maybe maybe it's because there isn't enough information in the tool motion maybe because we don't have enough machine learning background but it seems like if we can't even defend this basic case there's no point in going further. Also consider that there's fifty one million surgeries done and it states every year by about one hundred thousand surgeons and the majority of those are not robotic we don't have data for. But those big errors are happening with these big numbers how do we actually get a method that can scale and be correct to those big numbers so can we actually scale this can we do objective assessment as scale it accurately and this is where we proposed this somewhat controversial hypothesis that you guys seem to tell me very well within ten seconds who was a better surgeon and so we had this idea well can we just crowdsource this to non-experts aggregate their ratings and will they be equivalent to the back to the top by top experts. So crowdsourcing has been around for a long time it was founded by Lord Francis Galton the sort of grandfather of modern statistics in one thousand seven Nature paper it's an interesting story this is his story of the ox where he was. Kind of a controversial story he he was actually you Genesis he was trying to prove that there's a better class of human beings than another. And he wanted to scientifically prove that you shouldn't let the average person for example vote because they're an educated and incapable and so he found a little carnival where the game was somebody would bring out a huge box and if you could guess the rendered weight of the ox how much it weighs after all the good stuff is butchered how much is that way to within a pound you get it and people are lining up by the hundreds it's like a ha I got my experiment so he got somebody to tabulate all the guesses he went home analyzed that nobody was even close so he was going to say OK finally I could sort of quantify how wrong people can be but when you computed the median it was within a pound the exact rounded weight of the ox and that's basically by the way the founding of the central limit theorem where if you sample from a distribution of any any size it doesn't have to be normal and you keep averaging or you keep aggregating or taking the median that distribution is normal and all you need is enough data and equals thirty or more and you'll converge the true mean. And this has been around again for a while it's kind of like a fad comes comes and goes every ten twenty years recently sort of reviewed by sort of. In this book one of my favorite cases is where the folder probably folded a group in Stanford. Shown that you can get crowds of non-experts to outperform groups of top Ph D.'s on a complex protein folding problem that the crowd doesn't even understand but on average that they could actually outperformed them. So. Who are these crowd workers over six million are ready to work at any time through platforms like Amazon Mechanical Turk and others more than half are female more than half are educated with an advanced degree and that means that they are sufficiently diverse. To me the criteria for France a goal to crowdsourcing as long as your variables are independent and aggregated you're going to be good. So here's how we tested the hypothesis we gave. A bunch of crowd workers this one minute video this is a video of a robotic training task and and given the same exact survey instrument that expert faculty experts use. And ask them to objectively quantify the skill on exposed here had no idea what we were doing we gave them a dollar to look at this task which turned out to be way too much for these people. It turns out there's there's a lot of people with massive amount of free time on their hands that want nothing more than to do tasks for you for ten cents on the on Amazon Mechanical Turk which is great. And I kid you not the more you give them the more they like tell their friends and there seems to be no bottom to this. Well so then we test the hypothesis we got the scores from Turkey and we got the scores from ten faculty experts and let me draw your attention to this the means of the two were statistically identical pretty much just like the Francis Galton study. Which to us was really surprising we were we had question mark exclamation point that we didn't really trust at first. Was even more interesting is that it took less than twenty four hours to get the four hundred rating from the from the turkey again they've got nothing better to do and they're around for twenty four seven where is it took almost twenty four days almost a month to beg and plead ten surgeons just to watch a one minute video and give us the raid even though they're involved in the study but this sort of underscores the problem faculty surgeons they don't have the time they do not have the time to sit there and give their trainees all the attention or evaluation that they need. All right so we published that just remember presenting it at clinical conferences and it would just immediately polarize a room like nobody would be like OK that's interesting you are either that is amazing we need this yesterday or the other half would be like you're insane nobody is going to evaluate my skills with like a group of Homer Simpson off the street right. But the central limit theorem says that statistically this is going to work you're going to convert to the true meaning. So then the feedback we've got is like yeah but look this is a simulation task this is not surgery when you know what about when you go to live and that surgery surgery is so much more complex everybody gets what's supposed to happen here. So here comes some more life surgery the first idea where we actually tested an animal cases we had twelve poor sign bladder closures the pigs being used to train surgeons to use a dementia robot across of skill level you can see the ratings from the surgeons the faculty aggregated on this axis so for each dot you have about five to twelve surgeons that were averaging their scores for and the crowds about thirty to fifty. And we got a cone back south of point one two as a measure of concordance kind of like correlation. But numbers of point nine or above are considered good enough for high stakes assessment so we're really really surprised by this when we actually went to live surgery we got better numbers than than when we were doing simulated tasks and again the concordance was strong enough to actually merit some some really thorough study. And people who sort of caught wind of this we're getting a lot of phone calls from all sorts of people like the american your logical associate and they had this massive study where they're trying to validate a new curriculum to credential their surgeons and then did it with four hundred fifty four videos to evaluate and there was in the words of else with MacDougal the director of education at your Olivier never in my lifetime will I get my surgeons the people that she's the boss of to the way that many videos so they turn to us and I'll just going to get through this we got really good agreement with their experts and long story short they ended up using the crowd scores to validate their entire curriculum for the entire American people as the nation and they were able to so in about nine days we actually evaluated all those videos. Over sixteen thousand ratings in nine days which which is now we can actually scale up to those numbers you know hundred thousand students a year. We publish this it repeated locations there was a recent sort of summary of some results from JAMA surgery. But other people have now really picked this up there's now actually a review paper written by a clinical group about all the people using crowdsourcing in health care started from from the stuff. Then the first real study we did on live human cases was with this group the Michigan it's called The music group you can see what is the answer of there. It's actually really remarkable consortium over ninety percent of all of the year all that is the surgeon surgeons in the state of Michigan voluntarily nobody nobody is forcing them to do this voluntarily. Contribute pool their outcomes resources so they'll pool things like how they're doing just for the sake of self-improvement which is really remarkable So we partnered with this group they're running a study to try to replicate Burke Myers work to try to replicate the birth my hypothesis. And hypothesis was that our crowd we would be concurrent with their experts so the twelve videos were assessed. And what we found was as they ranked the scores from the expert reviewers in the middle column and discours with a review from the crowds in the far right column they agreed on the bottom five performers which is interesting now remember these are live cases on humans with outcomes and we are showing agreement between crowds that this very quickly and expert surgeons. Which is remarkable now. Actually work a lot better than we anticipated but you can also see there's some disagreement and here so for example they don't agree on the top performers and people say well yeah but the top performers don't matter what we're worried about are the people in the bottom quintile those are the people we need to help with with more training but we started getting suspicious because statistically the statistics is in favor of the crowds that's where you have the high powered the high numbers so we start getting suspicious about these experts scores like maybe maybe the gold standard in surgery is actually not the ground truth maybe the gold standard that they think is the best thing for scale is not accurate remember we're using a web a survey tool for all this stuff and so the clinicians are using the same web survey to every mouse click we're recording so we got suspicious and for an average video of thirty minutes in length we looked at how long it takes the faculty to review it which is how long it takes the crowd workers to review it and we caught him in the act the faculty weren't even watching the whole video they were barely washing and half were at the Mechanical Turk hers again they're spending more than thirteen minutes watching this video getting really excited about putting in comments on that kind of stuff. So clearly this is not the gold standard. You know what if they missed something in it in the middle of that video and for all we know you know maybe the faculty maybe they only need ten seconds to tell you exactly the skills so you know this doesn't say that they're making a mistake here. So if we're trying to compare a gold standard to ground truth we really need some sort of arbitrator and what is that you know we have crowd versus experts who is correct and that's where we bring in patient outcomes patient outcomes are the trump card does this actually benefit patients can you predict improvements in outcomes for patients. And it's a much harder problem but we've been working with a number of hospital networks and we've been collecting this data in long term and we've been able to show again this with these at so disclosure there. Incorporated the company we've been able to show that that scores correlate directly to patient outcomes so if we have crowd workers looking at your video. We can correlate to hospital readmission rates excess blood loss and length of stay and significant complications what was even more surprising. So it seems like you know the crowds agree with the outcomes and the and the faculty agree of the outcomes as well when this study in certain cases the crowds actually had better predictive power of the outcomes than the experts which is interesting we would which is a surprising result to us. And I'll just wrap it up here that this thing is like spread like wildfire there's. There are now entire hospital networks that are actually using this I'll just highlight two of them here one is out of business health us the sixth largest hospital network in the United States within two years every surgeon will be evaluated by this and by the way it's not the surgeons evaluating this is the risk assessment apartment every hospital every major network has a risk assessment apartment they have budget and a mandate to minimize risk to improve outcomes and they don't have tools to do it so they got a hold of this and they're going to implement this over their entire. Network and within the third year they will make credentialing decisions they will grant to revoke operating privileges based on the scores. Also mentioned briefly that we've been able to show that this works in not just you know high profile research institutions or expensive hospitals McCauley white Stanford. Actually did this on a fellowship in Ethiopia so he went out to a local clinic got a local smartphone that he got off the street took a bunch of videos and he showed that there for their medical school and suturing you can get the same level of accuracy as standard medical school for a particular valuation. So I'll just end this part with this the problem of quantifying surgical skill and surgery is not close it's not done I think we've just started and from machine learning it's been data starved for this entire time we can actually solve the problem of machine learning until we get really clean data but I think now we're finally getting to the point where we have massive databases they're very well labelled they correlate to outcomes and now we have a well formed problem for machine learning so we're putting together the DACs alliance if you're interested at all we're going to actually put these on public forums so machine learning experts you just get the data you get the labels and see how well you can make your algorithm perform and we have like a. An annual contest where we'll get out you know ten thousand dollars something in a prize. So if you're interested please email me what will put you on the list of people and when we actually publicize it all right that's the first half of the talk. First part of the talk the major part the other part is this will look even if we make every single surgeon an absolute expert in a master they'll still make mistakes humans make mistakes can we ever get that risk all the way down to zero because human errors and is guaranteed we're just human and so that's where this idea sort of comes in so we've seen how the surgeon patient interface is getting replaced by a digital interface and the rise of CO robots so if you've got a surgical robot you're at once a CO participant. A coworker with a surgeon but you can start acting as a codefendant to the patient what if a robot could actually detect an imminent error about to happen and not just alert the surgeon because they could ignore that but actually prevent it from happening in the first place or by design make it impossible for an error to happen so this kind of our goal is an error avoiding surgical robot and the idea is you detect something in real time before it happens and you automatically prevent it and we started with a very non-controversial area so if you go to surgeons and tell them Look we're going to take over take control of your emotions your directories they will have issues with that that's very controversial historically the surgeon is like a deity in the operating room they are in command of everything absolute authority and challenging that is is quite controversial. So we decided to go with a non-controversial problem it turns out when people use or tickle robots in practice there's no force feedback so you'd crush tissue all the time to crush injury is far more prevalent with a surgical robot have about a fifty percent increase just from using a tissue crush nobody's really dying from that your question is just really uncomfortable during recovery like like Question three hypothesis was that we could in real time using the data that the robot already has no new sensors using the robot data that's already present identify what tissue you have and based on that tissue throttle the force so that you get the traction that you need but you know you don't crush it. And here comes some sunlight footage careful. And the idea is you can see the case here we've got a surgical robot a grasper and as a grasping during the early part of the grasp we're just punching on the data trying to automatically prevent the question to be from happening we've got some models in place so the field of biomechanics has a bunch of classic work on static models non-linear models it looks like this and the problem is early on in the curve you can't dissemble you ate. The difference between let's say a liver and spleen but if you build in a dynamic model a real kind of manic model with the ridge time to. It is and what not there's a lot of discriminating information that happens much earlier and think about this you know sort of coming in they're going to grasp you have maybe hundred two hundred milliseconds to identify that tissue before it's too late so if we're using this it's not going to work we need to use a nonlinear dynamics potentially to do it and then we use this idea. Like computers freezing up we start the program Scuse me. So well that's happening the notion of shared control so in shared control you know you have a robot that let's say is autonomy and it's kind of like the autonomous driver idea and a human Now right now the human has absolute control and the notion of shared control is to. Open this up we go. If you and your. All right sorry about that here we go share control. When you have a human driver driving a plant like a robot which is what we've got now. There we go human driving a plant if Alpha the control variable is zero the human has absolute hundred percent control standard Center case in the operating room if Alpha is one human has no control and a computer artificial intelligence takes over and if Alpha is any number between zero and one you're smoothly blending your averaging or. Changing in time and Alpha can change very quickly so we've actually been able to show that this works you can see here adventure robot grasper taken right out of the operating room. This was used for some of the in vivo studies and you can see here if there's no share control on the human will pretty much always graft too hard so you could potentially entertain you that way but if you turn the shared control on within about one hundred milliseconds the identification happens we identify what issue it is throw the force fast enough and the surgeon doesn't know the difference will basically automated this lower level control loop or automated low level force control and they're just grasping tissue but it's not getting crushed and by the way this has been around for a long time share control we wouldn't invent this. Scheme and there's a bunch of work in the area but what we did find is that when we use the scheme right off the shelf just this alpha scheme the only requirement is that Alpha has to be monotonic with confidence that's the only like real between zero and one. What we found is that sometimes a system would just go unstable spontaneously which is not a good thing to be happening in surgery and what was going on is it's actually really sensitive to Alpha dot Alpha is changing very quickly your balance of stability are out so we'll be able to show is for example here is two controllers two simple stable if you are controllers if you blend them in any static way with a constant alpha stable Alpha changes very very slowly it's stable but it changes quickly you can not only lose performance you can destabilize the entire system which seems to me like in the literature people have just gotten lucky so far with slower experiments but we ended up with something across this because we need Alpha to change very quickly so we have. Trevor here is actually working on some theory to use passivity to be able to. Stabilize this no matter what. Let's move on to like a bigger problem so heart disease is the number one cause of death in the world in the US One out of four people that on average as you or the person next to you. The year is twenty seventeen and our best clinical options are still full open heart surgery coronary bypass. Invented in the one hundred fifty S. one of the most dramatic procedures or stenting so you get a little to put in to expand the stent there the underlying condition is this you get slower. You get plaque to slowly build up in your arteries shown here that yellow stuff starts as early as ten years of age in American children depending on diet and when that starts to grow over time you slow the flow of blood to the heart that's result in heart disease and when it gets clogged by either a piece of plaque that dislodges or a clot that's a heart attack and the downstream part of that flow whatever. Tissue that blood was feeding starts to die and that's why a heart attack is so dangerous that the same condition same mechanism occurs in the brain that is called a stroke. Again and this by the way is a leading contributor to the leading cause of death. Heart disease that rise of surgical robotics that you saw before Intuitive Surgical was going after this procedure and other minimally invasive heart procedures in the early two thousand a little known fact is they were on the verge of bankruptcy because they were not succeeding until the year all of us started using it and then it really took off. So let's look at the market it turns out everything is either bypass surgery or. Stents the underlying problem getting the plaque out of there it's called Etheredge to me removing the actual plaque is almost never done and there's another population here called no option patients which is not small there's actually roughly the same number of no option patients as prostate patients prostate removal patients which drove the explosion of sort of. Robotics So there's a tremendous opportunity here if we can get a surgical robotics to treat this condition you could really disrupt a massive amount of health care in a positive way but you can't compete with stents you see there are actually companies right now that make stents that for example dissolve and there are they're failing because you can't compete with us that if you're stent cost three times as much and you can prove that it's better they're going to going to go into the cheap stent anyway. And so our strategy is to actually go after these new Often patients or individuals who arteries are so torturous you can't get a stent there's no catheter that's going to go in and navigate their torturous turning. And they're not good candidates for surgery but if you can bring the precision of robotics to safely imprecisely walk through those arteries take out the plaque in no option patients if you can do all those three potentially have a disruptive technology first of all there's no competitor there's no competitive market if you could do it for the new option patients you get your foot in the door in the clinic and then the cardiologist interventionists will start using it for all the other procedures and you could potentially disrupt cabbage a coronary bypass and stenting. And by the way I think it's a matter of time before somebody does it you know it's not if somebody's going to do this but when and who so our approach to this has been a little bit different we decided to sort of reinvent how catheters work catheters have been around they've been in horses since the eighty's hundreds and for the entire time people have been pushing catheters of the tips of a kind of what it looks like you get this long slender catheter introduced in a blood vessel Let's listen to this a plebian here and it goes into the vessels of the heart under it and you're pushing at the back end and trying to get control of the front end and once you're going through a bunch of anatomy that becomes complicated and difficult so we decided to sort of reinvent this and say what if we took our catheter that's a catheter inside of a blood vessel and sort of pushing it from the back and we let it pull itself at the tip So imagine this is a catheter walking through a blood vessel. And this will motion mechanism this kind of motion if you will. It's predicated on those here with these so we're using a little helix that spiral because if you use a balloon you block blood flow and that's a heart attack that we're trying to treat. But if you use the helix you can anchor into the vessel and still have blood flow so you are not coming out on procedure time and the idea that this is a soft robot so it's inherently soft and the compliant you can't damage the blood vessels even if you tried when you get to where the plaque is yet another degrees of freedom that will articulate and police are removing the plaque I'll show you a technique for that little bit later. For this we're using hydraulics and McKibben so I'll actually get to some of this stuff for the sake of time we've built a few of them the basic idea is you're wrapping a tube with fibers and you can make that to turn to whatever shape you want and be very strong building a looks kind of like this we have a little lay that we hacked so that we could wind fibers onto them we can model this thing the model is actually pretty accurate for putting in pressure so this is sailing that's going to hear the relationship between volume and pressure as a fourth order polynomial not very complicated. Now the question is how do we get serial locomotion the blood vessels of a beating heart we're talking about like a two millimeter diameter so this has to be small there's no way we're going to get parallel actuation we're not going to get four lines of pressure two in the Bentley control for five. Actuators we get one how do we control how do we get this motion out of one actuator of one line of pressure and the idea was this imagine I had a little R.C. circuit if I apply a square wave of voltage this capacitor charges first and then this one and then this one very simple idea passive circuit and if I discharge it get it to zero volts this one destroyed is first and then this one and then this one and by tuning the resistances I get to the timing of this thing so our system was a mechanical system this was a resistor it was just a simple flow restrictor So a little valve a little set screw that pinches this and is governed by the or physical Asian fits the model pretty. Well and you end up with a pretty hairy non-linear model each P.C. is a fourth order polynomial but with that you can optimize. To basically say one of the two settings on these two knobs one of my two resistance values to give me the motion that I want that's most effective. And it works so this is a large scale model this is that just under a centimeter in diameter for the first work but you can see it working under robotic control. And. It was simple enough actually that you can drive it by hand so this is actually being driven by a syringe and failing. All the parts or M.R.I. compatible disposable is very inexpensive So now the only challenges is to scale down which is which is still. A challenge but doable and. We point out in body intelligence what you're seeing here is a fish there's a well known fact that if you take a fish gut it and maybe even take out his brain you put it back in the water will swim away. Is this notion that we most of the control and also like in the eighty's there was there's some weird work on cats where they would get the capitated cat and put it on a treadmill and we still keep walking. And this notion is that there's in a million control groups there's embodied intelligence you don't do it like your brain doesn't close all the control loops you do supervisory things like tell your limbs to walk and they just magically do it because they have a body intelligence there's a lower level control it's doing all the complicated stuff as if it's in this example you take out the central system and the lower level loops they just interact with their environment to create swimming. And so our sort of contention is that this is the same thing going on in our little spiral mechanism here that as long as you're putting energy in to figure out how to local note there's no need for advanced sensing or control. All right so I mentioned walking through Anatomy what about no option patients so these are patients again whose anatomy is so torturous there is no single device that can that can navigate their anatomy. And there were three D. printing comes in so we get a C.T. scan these are actually now available. Tools like from V.M. T.K. The vascular modeling toolkit you get a C.T. scan and they could. For example compute the centerlines automatically from the from the C.T. scan. So you can get the geometry of the particular patient a really challenging geometry Well let's say from that challenging geometry we have the initial shape of my catheter which is always going to be a small small cylinder as I can get it and the final shape so here I'm showing us a spiral but it could be any weird shape you want. Any weird amorphous shape right that it can conform that anatomy that's really unique. So here's our idea we're going to do in versus line and sort of starting out with. With a mechanism or a manufacturing technique we're going to know who the patient needs how do we get this thing to actually get built in versus I'm here's what they need. Make it happen and here's an idea if I know that initial and final shape then for any point on that body I can see how much local differ mation there has to be an isotropic defamation if I know how much local determination there has to be I can back project that onto the material and say the material stiffness has to be has to have the certain properties in that little pixel of voxel of material well that's pretty exciting because it lets it go directly from a patient's needs to a blueprint the ideal blueprint if we can give this to a three D. printer we can print a patient specific actuator that would be ideal for this patient is the idea. And we've been sort of working with the with the group in chemical engineering on this. And then get through this to say that we've talked about this is so great it looks like we could actually look I'm a through arteries and possibly do it and no option patients in and keep in mind that the economies of scale are there to actually do this there's a lot of a large number of these patients questions now is how do we remove the plaque so we get there how you take stuff out. The extra laser This is the same technology and Lasik eye surgery it. Fascinating technology you get a pull of that light that is pico seconds and duration there's some bubbling and so that happens afterwards and it doesn't heat up tissue a regular laser just cooks tissue it's a thermal ablation process this laser pulses tissue with light at a such a high intensity that it is the middle of the molecular bonds the particles are smaller than a blood cell that result and you get these fifty micron you can basically mill tissue with Micron accuracy that's why they say they use a school to lens doesn't heat things up well this thing is F.D.A. approved already it was actually a big deal the one nine hundred ninety S. and it flopped because it was a little unsafe. It's already F.D.A. approved for use in patients plaque you can see one of them working here and we had a really simple idea right now that the reason why this is not used. To me surgeons really clinicians do not like it because when you're using this thing you can't see anything you can see soft tissue you're looking at basically an X. ray and real time soft tissues will show up on X. ray so you can very quickly through plaque and start leading through the vessel and other patients bleeding out and you have an emergency procedure you have to do so is perceived as unsafe so we said well what if during the off time we have a twenty four millisecond that's like a lifetime for engineering right what if we just queried the light on some light down to look at a light coming back most black is visible to the naked eye these are not small signals we're talking about our political results so that we could actually in real time detect the difference between plaque and artery wall at least for a specific patient. And then actually we have this thing up into the eczema laser So what you're seeing here is the notion of an error avoiding surgical robot we have a surgeon in this case the. Grad student. Doing a mock task the idea is the task is so easy any human expert with decent visual acuity can sit down and do that task expertly Now this task is we're saying so the idea is you want to only want to leave the white stuff and leave the yellow stuff. Anybody can do this. We're showing here is that when you put the laser peddle on and you just indiscriminately lazing everything we can automatically shut it off when you get to the sensitive areas of tissue so even if a surgeon is trying to make a mistake and cut tissue that they shouldn't be we won't this algorithm won't let him actually do it and then we did a small user study. Where with five different people for different trials each we asked them to us as carefully as possible lays as quickly as possible as if they were trying to get all this tissue and showed that even on the super simple task everybody is an expert. We could get improved performance so you had lower errors even though people shouldn't be making zero errors they're still making errors and we can reduce those errors at that margin so the clinician got excited about this we got to be a little controversial but they said no we know it's hard we actually want this now you know in the operating room. All right. And I'll just wrap up with this the final slide is kind of a completely left turn you know big idea. What if robots instead of us trying to incrementally improve surgery because surgeon say that they want you know a sharper scalpel that there's that classic quote Miss attributed to Henry Ford if I asked people what they would have wanted they would have told me a faster horse. But sometimes you could have different ideas and the question is maybe with with robotics we can actually do something drastically different so surgery has been a subtractive manufacturing process we give her disk out and they traditionally take tissue out what if we can give them a little wand that could add tissue back in the right location and irrespective of human motion you know a beating heart. And so that's kind of our idea to do dynamic bio printing and the field by opening by the way is doing very well there's they've been successful transplants into mice you can get stem cells from mouse. An organ there was a study I think in nature on successfully transplanting uterus into five mice and they could actually carry pops successfully So there are some very early work I'll just skip through this but long story short. We were able to. Turn down. This is. Where you can three D. printer directly onto really moving human anatomy. Now we're not by opening people we're actually working with Anthony Attala who's a bio printing sort of figure they do the chemistry in the cells what we're really interested in is tracking motion and getting a robot to subtract out the motion right. And the application here would be for burn patients so for burn patients actually at Intel's been doing this and a group in Australia they can take stem cells out of your stomach make basically a little concoction for second degree burn they could airbrush that on and your tissue will spontaneously grow back now the downside is you can't get really good you can get thickness and you can get good geometries but this to me at all it was actually really excited about this because now you can you could potentially do the stuff in vivo you could you could bring the benefit of bio printing. Onto a living patient. So I think. I think I will stop there just to think our sponsors and all the grassroots to actually make this work possible. And all wrapped up with saying that. Computational surgery so you know we started this talk with Hunter showing up applying the scientific method to surgery and I think now there's kind of a new renaissance happening because there's so much more American quantitative rigor penetrating the operating room with all these new technologies I think we're poised with feel that compositional surgery and robotics to have a new renaissance in that area so that I'll say thank you and I'll take any questions. So why so yeah. Right. The. Yes. I will I love what. I see. Now the great question. So it's a bit to the first comma but the spirit was actually really tragic because even though he I think this is what you're referring to even though he got religion in a scientific data he was ridiculed for it and for the rest of his life I think he ended up like losing and he had a really sad story. But she was fascinating so historically you Robert G. has traditionally been a leader in a lot of technologies so they're the first and the scopic procedure for example part of that is to fall I think they have a culture of being. Let's say not risk averse you know they're interested in new technologies and trying it out and also when you're all of your chances of doing some really serious damage are in some ways way lower like if you got first of all beating heart it's very difficult to get in there if you mess anything up you know you start bleeding that's a really serious going to. Right Whereas in your ology you can put things through the year or prettiness Li and do a do some damage and the patient is still be fine so it tends to be a safer proving ground for a lot of these technologies so I think the answer is twofold is that it's easier to get in there and the to and the cultures there where they actually want to use it and then the other reason is the division of robot didn't really meet the needs of what cardiovascular surgeon wanted you know if you think about you have a stiff dangerous tool next to a delicate beating heart it's a bad design decision right whereas in prostate surgery first of all they give surgeon the wrist which was a revolution and a prostate surgery it's really really hard to access you've got a bone that you're contending with need to be able to reach around and start tying knots and getting a wrist was just the best thing ever and I think that's part of why it's such a good match for that particular robot that it took off. Thank you yes and so so that's a great question that there's a great slide by Apollo Daria was it one of these huge figures in our field where we can address a map it all out so open surgery was macro scale and then you know biomedical biological cell biology was coming up of this. So they were nano scale and the future they're going to sort of meet together and I'm kind of still in this mess of scale you know I'm still thinking about catheters roughly a millimeter in diameter but there are folks working so that like best seller and campus she's working on. Gold macro particles but basically nano particles that you can sort of to do with to basically identify factors that made them attracted to cancer cells and then you know it in with therapy I think there's probably always going to be a place for for a macro to mess with scale stuff especially and congenital defects but I think the future is probably going to see a lot more of the nano scale stuff it's just hard it's hard to get and I think one of the fundamental limitations in this group try to do is get stuff down that awesome robot for example Bob Webster with was involved in this where. You have a bunch of capsules in a cup you drain the capsules they sell someone to a robot it's out of your stomach to do a surgery disassemble and come out right and the fundamental issue they had was power to generally get surgery done you need a certain amount of mechanical power and force and displacement and so you need the energy density and that's why we're stuck with hydraulics that we think hydraulics you have the highest energy density of any technology known to man right so higher than anything electromechanical So if you need any forces you're stuck with that only with a nano scale you couldn't necessarily get accomplished so it's over the procedures that you need to like you know Rip tear tissues out a blade tissues is probably going to get enough All right thank you all.