have you also held editor positions at medical journals yes i was editor in chief of the journal called the american journal of response critical care medicine so that the premier journal in the world for all along disease it's also the premier journal than the world for intensive care medicine and it's the official journal of the american thoracic society. have you talked and lectured outside of illinois and or texas yes. generally where like should all or around the world mean that lectured in more than 30 different countries around the world and probably the best majority of states within the united states minnesota is one of the states and guys states about minnesota that shoot in minutes so it had been in the mayo clinic several times as a lecture. were you given an award from the mayo clinic yes i was given an award

called the bow lecture in the mayo clinic and they give it out to one doctor every 10 years and that it's only to one doctor it doesn't matter what specialty so it could be around you're a surgery gynecology whatever you just pick one person every 10 years and was afraid of being a particular that you were recognized by the mayo clinic no just from my work. as a researcher in clinical medicine. have you also published in basic science journals such as the general of applied physiology yes i've published a lot of work on basic science that wouldn't necessarily be directly related to medicine in the journal of applied physiology the jurors may not be familiar with what physiology is as a science general explain to me physiology is basically how the body works you want to know the science of how it works you want to deeper understanding of what are really the mechanisms that make the body does what it does. within the field of

physiology is there a particular focus or actress you have i'm primarily interested in breathing in the bigger area and so with breathing that would mean how the brain regulates your breathing how the brain sends signals down to the muscles that control your breathing your diaphragm your rib cage and then how you expand your chest and how you overcome forces within your chest like resistance within your chest and all the rest of it to get air moving in and out of your lungs and then the particular forces that you generate in terms of the pressures within your chest that will enable breathing to occur with the ultimate purpose of getting oxygen in and getting rid of carbon dioxide. and you consider this a part of the study of medicine it's not quite as part of the study of medicine

it's really quite separate because it's more of the basic physiology so it's more in the realm of math and physics but then it's applied or because to be a good doctor you need to have a good knowledge of science but the science part is really for separate from the medical part and it's to try and calm down on the science as best as possible. how long you've been working at respiratory physiology since 1901. for use and what exactly drew you to the physiology of breathing mean because i was going into palmer at that stage an us already directed at spent 5 years doing lung disease and i just wanted to really know how you breed and i want to come up with new knowledge because everybody thought everybody knew everything about. and then thought it would be fun to find out a new stuff. so dr do you know of others can in your field who have been

studying respiratory physiology for 46 years know i mean i know enough about him along the way but i mean i would know no more than a handful or less of people who are still doing physiology at the patient's bedside . for 6 years. so dr let's change subjects and talk a little bit about your experience or work as serving as an expert. who served as an expert witness before yes i have what types of cases. practically all of them have been in medical practice done it for both the plaintiff or the patient side and have done for did the fence for the physician side have you ever been involved in a criminal case before no i have never been involved in criminal cases have you testified in court before i've testified in court i don't keep track of the numbers but i

suspect i've been in court but 50 times would you tell the ladies and gentlemen if you're getting paid for your time in this case no i'm not getting paid and why is that. when i was asked to do the case. i thought i might have some pain knowledge that would be helpful to explain how mr floyd died and that since i had never done this type of work in this nature before i decided i didn't wish to be paid for it. so did you volunteer to the state of minnesota or did the state of minnesota call you these state of minnesota contacted me. what were you asked to do doctor told i was asked to review the medical records related to the case these were medical records from hannaman county then there were a number of interviews of people that are interviewed i was given

a long list of these and primarily it was related to looking at a large number of different videos. course and a big part was that i needed to redone the scientific background of all the various aspects related. so let's talk about your opinions with respect to this case have you formed an opinion to a reasonable degree of medical certainty of the cause of mr floyd's death yes i have would you please tell the jury what that opinion or opinions are. yes mr floyd died from a low level of oxygen and this caused damage to his brain that we see and it also caused. a arrhythmia that caused his heart to stop and by p.e.a.c.e. i mean pulseless electrical activity correct it's a particular form of

a nap normally be to the heart in a written and particular form. is this what some persons might refer to as. yes it has been called this fix it to me itch it's not terribly helpful it just about who are really talking about is a low level of oxygen other people talk about hypoxia that again is just a latin term meaning a low level of oxygen so all of this is just really other words for a phenomenon that is a low level of oxygen. have you formed an opinion to a reason agree medical certainty as to what the cause is or was for the low level of oxygen in this to floyd yes i have would you tell us what that is the cause of the low level of oxygen was shallow pretty the. small breaths small tidal volumes shallow breaths that we're going to be able to carry the air

through his lungs down to the essential areas of the lungs that get oxygen into the blood and get rid of the carbon dioxide that's the alveoli at the bottom of that i'm. told and now we're using a short video that you prepared to help you explain to the jurors how oxygen gets into the lungs in the mine. i want an oxygen you know i'm going to show you what's been marked as exhibit 950. kids can you describe 1st what that is so you are looking at the lungs inside a body and we see here that you can see the windpipe up at the top that's shaky and then that's it's in for the brunt. and also you can see that diaphragm down at the bottom and when the diaphragm contracts it looks sort of we're in movie the jurors

can't see it yet so i'm just happy just that oh i'm sorry parents are. going to offer to. exhibit on 50. 50 is received yeah we can i will display it so the jurors can see it. because in our looking and you can see the contraction of the diaphragm that's the kind of pink area down at the bottom we see air going down through the wind pipe and then proceeding down to the bronx. and then it was going to continue down the brown q. tubes onto that will reach out to the air sacs which will be the guy and now we're seeing that we're moving down here and these are like the great like structures down at the bottom and this is where all the action occurs the oxygen goes across those air sacs and also the c o 2 goes across them then it's expelled back out of that's everything in

a very rapid video. so then what what do you. what happened in the case of mr floyd that relates to the shallow breathing that resulted in his low oxygen so there are a number of forces that lead to that he's the size of his breath became so small and so there'd as series of forces higher up that are leading to that in the brain forces that are going to lead to the shallow breath that are going to be that he's turned pro on on the street that he has the handcuffs in place combined with the street and then that he has a knee on his neck and then that he has a need on his back and on his side all of these 4 forces are ultimately going to result in the low tide low volume which gives you the shallow breaths that we saw here and so the air will not be able to reach those air sacs we just saw on the

video where the oxygen is exchange in the car and dioxide is removed doctors a concept that if the respiratory medicine feel not as that space yes there is how does that relate to mr florey so if if you think of the video back all the way until you saw those clusters of green. it's where you saw the blood vessels surrounding the field on everything up to there is that space so i as you're breathing in you're breathing in through your nose your mouth goes down through your windpipe down through the bronx your tubes radiating out onto reaches the air sacs up to you get that the air sacs it's all that space because the reason we call it is because no oxygen can get across those brown kids' shoes no carbon that dioxide can get across that they are and the carbon they're the only place that that gets across is those that you great like structures so everything in the lungs

before that is that space. so you mentioned several reasons for mr floyd's low oxygen and i just want to capture those for the jury and then we'll talk about oh. you mentioned one hand cuffs and the street. correct. you mention me on the neck you know. from my right and you know what i didn't get an a in school. the problem position you have and then that the knee on the back. arm inside with those the forget it these are the form.

so we want to talk about each of these but before we do that. might it be helpful for explaining the excessive money to the jury for for them to see the relative positioning of the various officers on this to floyd's body when he was subdued on the ground yes i think that would be very helpful did you assist in preparing an illustration to show the relative position of the officers on the ground yes i did and that let me show you what's been marked. as exhibit 949. could you just tell us just designed to describe generally for the record when idiots i mean i watched the videos and certain segments of the videos hundreds of times and it's very difficult to kind of get an overall view of where everybody is positioned because you're seeing different videos from different angles and so the artist has taken all the

different videos here and he's combined them into one moment in time and you can see here and also he would remove the police feet so you're going to get a better view so you're looking kind of at a bird's eye view of where mr floyd is lying and where the officers are positioned in relationship to mr flynt. so that the purpose of this it is to show the relative positions of the officers and correct. your honor would offer exhibit $940.00 that. is receive. so what what point in time if you say told us that this was at a particular point in tat it is a particular point in time i don't remember the exact minute 2nd at the top of my head but. a 21 to 44 seconds that's right it.

very. quickly. ok so let's walk through exhibit 949 you can advance. in fact or tell us what receive ok you have now if you can see the couriers we rotated your it was to see. see officer kenya and then officer lane down at his feet you see underneath mr floyd in the turret it's been rotated the car has been removed and so you're able to see how they're positioned at different points in

terms of with officer shave him with his left knee on the neck he's right on the on mr floyd's arm and chest and then you can see here up a certain lane holding his legs and then you can see officer king with he's in the on his torso. so this represents a snapshot in time as you told us did the officers positions change over time as they were there on the ground yes they the officers positions changed over time and also the position of mr floyd himself changed over time and these become relevant in how we evaluate everything. and was it something you factored into your analysis that yes. did you consider where risk to show and he was during the encounter. yes for opposite shop and

left knee is for chile on the neck for the vast majority of the time and when you say bad majority are you able to be more it's more than 90 percent of the time in my calculations there are certain times where it becomes difficult because you don't get a good view of where it is so for example i know that an officer sharpens right needs on his back 57 percent of the time the reason i'm not able to say for the 43 percent is that i don't get a good few other times i don't have a good view of exactly where it is so did you focus on the 1st 5 minutes and few seconds focused on the 1st 5 minutes 3 seconds because that is up to the time that we see evidence of brain injury. so if mr chavez rightly was on his back from time to time. at other

times it was placed where your observation was placed on his arm or and then rammed in to mr floyd's left chest so really whether you're making a distinction of whether the knee is on the chest per se or whether it's on the left arm and rammed in against the left chest from the point of view of. the effects are extremely similar. so let's let's turn to the number one on the. oh you side of them of that q. . so i want to turn back to the notes that the number one here that written down for the reasons you told us for floyd's law question was to force locks region

handcuffs and the street to talk about the 1st. could you 1st dr token tell us how these various mechanisms the 4 that you discuss handcuffs on the street knee on the neck prone position knee on the neck back. on the back arm and side how do those mechanisms fall into your work either respiratory physiology or clinical medicine they don't have an awful lot to do with clinical medicine but they are directly related to my work in physiology so in understanding the forces that the body has to cope with these become these are crucial into the terms of the berries forces that are involved in physiology so then turning to the the 1st one in handcuffs in the street the very 1st one what is

the effect of the handcuffs and the context of what happened to mr floyd the hank of are extremely important to mr floyd. but the hank ups and their own just hank per se are not that important it must be the handcuffs combined with the street and it's because of the positioning of the hank of set the back then how he's manipulate it with the handcuffs by both the officer sharpen and by officer cain how they manipulate the handcuffs and they're pushing the handcuffs into his back and pushing them high then on the other side you have the street so the street is playing a crucial part because he's against the hard asphalt street so the way they're pushing down on his handcuffs combined with the street his left side and it's particularly the left side we see that it's like the left side is in a vice it's totally being pushed in squeezed in from each side from the street

at the bottom and then from the the way that the handcuffs are manipulated that's not just the handcuffs it's how the handcuffs are being held how they're being pushed where they're being pushed that it totally interfere with central features of how we bleed so mr floyd as pancake between the pavement and the feminine force on top of precisely now could you help us to explain how this mechanism the handcuffs and the st how does that explain the shallow breathing that you describe so this gets back to how we breed and this is fairly simple so the way we breathe we have 2 big muscles that help as with the we have the diaphragm and we have the rib cage muscles. the diaphragm can does

about 70 percent of what we need for breathing and about 30 percent of it comes from the rib cage and there is when the dive from country x. are the rib cage contract they expand the chest and when you expand the chest then air flows in from outside and it's coming in and that's our that happens on inspiration but to expand the chest there's 2 crucial actions that have to happen and we refer to these by the terms pump handle and bucket handle so if bucket handle is simple so if you have a regular bucket that you carry water with and you lift up the handle of the pocket the handle comes up like this and so when you contract your diaphragm you are performing a bucket handle movement of on the rip cage so you contracture diaphragm like that and each time as you inspire you can see it yourself as you inspire and each of you

there in the jury spar you see that your rib cage is going outwards like that that a bucket handler movement the 2nd movement that you have is called the pump handle and this reflects through an old water pump that would be in the yard for. getting pumping out water and so you have to handle at the top of the pump and you lift up the handle of the pop each time and the water comes out the spout at the bottom so you're filling up your container of water so with that action you're lifting up your this refers to the front to back movement of the chest or so with the pump handle your chest goes out with each breath and so you can do it yourself as you take a deep breath you can feel that front to back your expanding your chest the front to back expansion of your chest. is with your pump and. the sun at the same time

you're doing both of them at the same time at the same time you're doing that your chest is expanding from site to site and that which are bucket and so both of these are recurring and these are vital but that these you can't breathe if you don't have the bucket handle working at the pump handle work and there's not nap and there's nowhere going to get in there so dr do you have a photograph that you brought that would help by the better understand the pump handle and bucket handle yes let me show you what's been marked as state's exhibit 951. do you recognize what this photograph depicts yes. is it an accurate portrayal of of a certain incident presented as it is will help explain the testimony yes. this is an event that happened in the diary over not just and i'm not opposed to

office who are gonna. offer exhibit not 50 what if that. touched. sober.

the parties in court and whether discussing with the judge the evidence that they are about to show to the course of action as this where the microphones didn't turn off. dr in this case were you able to observe whether it was the voice breathing was impacted by the handcuffs and the placement of the street. what did you observe dr but what i observed is particularly as in terms of the hands of the police and the

handcuffs particularly on the left side so they were forcing his left wrist up into his chest forcing it in tight against his chest forcing it high up and you have to keep in mind that the opposite side of this is the street so he was been squashed between the 2 sides and so this meant that he couldn't exert his pump handle because in the street totally blocked his pump handle there was no way he could do any front to back movement and again the way they were pressing him on the back there was absolutely no way that he could do any front to back movement then in addition because of the knee that was rammed in against that the left side of his chest sometimes the knee was down on the arm or in against the chest so this would have the same effect so basically on the left side of his lawn. it was

almost like a surgical knew monette to me it was almost to the effect as if a surgeon had gone in and removed the long quite but along those lines there was virtually very little opportunity for him to be able to get any air to move into the left side of his chest how he was going to be totally dependent on what he would be able to do with the right side. have you selected any footage from the party worn cameras that you feel depicts mr floyd struggles debris yes. i'm going to show you what's been marked as state's exhibit 944. and 1st would you describe what it is what what you see in here is the back the top of the jurors aren't seeing it yet it's just as well i'm sorry record. they would not see this i'm describing what i'm see for now yes yes ok that's fine. but

what i'm seeing is that he is the left hand he's been grabbed by the police officers so that the hank of the left hand and it's been pushed into his chest so he's just not able to expand that in addition you know that what i'm seeing. on. the level of all of a turn ok i'm a current and i misunderstand what we offer state's exhibit number 44. 44 does. are now back to top of the jurors can see it ok so i apologize. for the right which you tell us what the other difficult so let me now you're able to see here with the lower arrow you're able to see that the officer is holding mr floyd's left hand he's holding it very firmly there's

a very firm grasp on it and then mr floyd's left hand he's been pushed in against his chest also we're able to see just on the side that officer sharpens is coming in and that's compressing in against his side as well so the ability to expand his left. left side here is enormously impaired and also you're seeing that the size of the chain between the 2 the right side and the left side is very short so he his whole left arm is also been pulled over and so it's preventing him also from expanding the right side i've been focusing on the pocket hand and the pump handle on the left but you can also see here that these are impaired his ability to expand his chest and of course the key factor you must keep that it's in kind of in a sense.