tv Day 9 of Trial for Derek Chauvin Accused in Death of George Floyd CSPAN April 8, 2021 1:09pm-2:31pm EDT
>> at the hennepin county courthouse in minneapolis day nine of the trial derek chobani charged in the death of george floyd. they're taking a lunch break until about two: eastern. 1:30 essential or so we will be back with live coverage, hearing from doctor mark bowman, a knowledge is of the events, to begin their cross-examination so our live coverage will resume a reminder to showing the entire trial of the night, the entire day's proceedings in eastern europe on c-span2 and if you miss any of the previous day is available at c-span.org. at the lunch break is underway we willshow you testimony from earlier today . >> good morning everybody.
>> if you wouldn't mind removing your master your testimony. and also to make sure the microphone is properly placed have you state your only . >> martin tobin. >> good morning doctor tobin. >> good morning mister blackwell. >> would you tell us what your current employment . >> i am a physician in primary criticalcare medicine . >>whereabouts . >> in chicago at ymca hospital and i will be university medical school. >> and and designs be a large facility ? >> it use to be the largest va hospital in the country i think. it's now been supersededby one or two others . >> and you specialize in pulmonology denmark.
>> i specialize in pulmonology and critical care medicine. >> would you tell the jury what pulmonology is. >> will now pulmonology is the study of the lungs. it deals with all diseases affect the respiratory system . the lungs, the chest wall. >> what are the various elements and components of the respiratory system other than the lungs and chest wall ? >> the respiratory system begins at the news, the mouth and goes down to the back of the throat, down to the light the bronchial tubes and then down the alveolar air sacs. these are the small break like structures at the bottom where all the gasexchange takes place . where oxygen gets in and carbon dioxide is removed. >> this is the system for getting oxygen into the body. >> is the primary purpose.
>> at heinz hospital do you work in intensive care unit? >> i worked in the medical intensive care unit. >> and that's considered clinical care. >> these words all have the same meaning. >> is critical care difference from emergency medicine? >> yes, emergency medicine. emergency medicine is the front door of the hospital, his triage area where you where people need to go. where is the critical care, is where you take the very sick people. >> what kind of patients do you see in the icu ? >> in the icu, probably more than half patients requiring mechanical ventilation so there on a respirator to help them with their reading another potential member will not be on a respirator but they are the primary problems relate to their lungs so that
might make up 70 percent or so. then the remaining patients will drive overdoses, alcohol withdrawal, diana, sepsis, things like that. >> do you only see the patientsin need of respiratory care ?>> know, once they come into the icu they are our patients, i am the primary care for everyone who comes in. >> how long have you been physician. >> i've been a physician three months short of five or six years. >> where did you go to school mark. >> i went to medical school in dublin ireland and i got my degree there. >> not that anybody noticed the accident what are you from dublin? >> i'm not from dublin, a small village in county kilkenny in rural ireland. >> what degrees you'll?
>> what degrees. >> the degree i hold is the mba degree which is at irish equivalent of the american mba and subsequently i've got an and the two research. >> are you currently licensed? >> yes, i'm licensed in the state of illinois. in the past i was licensed in ireland, in england and number of us the can all laugh because the only place i'm practicing is in illinois. >> board certified western mark. >> yes, i'm board-certified ininternal medicine . momentary medicine. >> so you still are actively caring for patients ? >> yes, i was taking care of patients in the icu last week and on monday i go straight back into the icu again . >> how long have you held positions at the loyola university school of medicine ? >> at loyola 42 years almost.
>> before going to loyola, were you practicing medicine somewhere else? >> i spent seven years at the university of texas at houston. >> did you also set up a sleep clinic in houston? >> yes i did and that would have been in the early 80s so i set up one of the first sleep labs in the united states for evaluating patients with obstructive sleep apnea. >> how do sleep disorder that within your expertise . >> because this is related against breathing and the problems with sleep, particularly people who snore , the people who snore during the nighttime, they include their upper airway and they can totally stop breathing. 500, 600 times a night and during that time the level of oxygen will go very low. the basic problem in sleep
apnea is because the soft passage, meaning the roof of your mouth is your heart, and just if you look in the mirror, little piece hanging down at the back is your due july that james in against the back of your throat and it gets included. 500 times a night in somebody who has sleep apnea. >> and it is that kind of research or transform medicine related toyour work in this case ? >> yes, it's pertinent to the case of mister floyd because obviously in apnea the problem is wrote, and as we will see in mister floyd's x then she'll problem are where the obstruction is occurring, is hyper variance which is again the back of the throat, it has also an overlap to patients with sleep you. >> we will come back to the
larynx in a little bit area are you also engaged in medical research ? >> i'm sorry. >> are you also engaged in medical research ? >> i've been doing medical research he's one. >> what kind of researchi've been doing ? >> all my research is basically related, it's kind of looking at breathing in patients with lung disease, people with lung disease who walk in the door to the clinic and also patients who are in the icu and patience for acquiring that kind of ventilation but i do a lot of research that has nothing to do with medicine just to know how people three. >> and you offered a textbook on the subject of ventilation ? >> yes, i've offered a large on mechanical ventilation that's called the principles
and practice of mechanical ventilation . >> so by showing the cover of your textbook here, on the camera, is this the book you are free to? >> is correct. >> 1500 pages. >> ,1500 pages. >> are you with the mcat medical journal? >> the lancet is one of the top medical journals in the world. >> and does a medical journal for two this book as the viral mechanical ventilation western mark. >> it has folded. >> also. >> yes, i have. >> how many. >> i think i published eight or nine other books. >> and it at all related to respiration or respiratory failure ? >> belongs.
>> have you published articles and abstracts also? >> yes i have. >> how many of those. >> i lose but i think i published more than hundred 50 of them probablyor something. >> and you published in the new england journal of medicine ? >> yes, i've done several articles. >> the journal of theamerican medical association . >> yes. >> spec in medical journals and oral? >> they are, yes. >> also held positions in journals? >> yes, editor-in-chief of the journal of the american journal care medicine so that's the primary in the world for all lung disease. it's also the primary journal in the worldfor intensive care medicine .and it's the official journal of the american jurassic society. >> have you talked and lectured outside of illinois and through texas?
>> generally, where. >> i've lectured all around the world. lecture in more than 13 different countries around the world, probably vast majority of the united states . >> minnesota is one of the states in the united states, minnesota ? >> in the minnesota. >> were you given an award from the mayo clinic? >> i was given an award called the bow lecturer in the mayo clinic and they get out whiledoctor every 10 years only one doctor . it doesn't matter what specialist, around neurosurgery, apology or whatever. they just pick one person every 10 years. >> was it for anything in particular you are recognized by the mayo clinic ? >> know, just from my work as a researcher. >> you published in basic
science journals such as the journal of applied physiology . >> yes, i published work on basic science that would be directly related to medicine. in the journal of applied physiology. >> the jurors may not be familiar with what physiology is as a science. you explained. >> physiology is how the body works. you want to know the science of how it works. you want a deeper understanding of what are the mechanisms that make the body up. >> within the field of physiology is therea particular focus or interest you have ? >> i'm primarily interested in breathing and the bigger area so with breathing, that would mean how the brain regulates your breathing. the brain signals down to the muscles that control your breathing, your diaphragm, your medicaid and then how you expand your chest and how you overcome forces within your chest 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 ? >> you consider this a part of the study of medicine. >> it's not quite a part of the study of medicine, it's separate because it's more the basic physiology so it's more in the realm of math and physics but then it's applied for because to the good doctor you need to have a good knowledge of science but the science part is really separate from the medical part and it's to try and cool down under science as best as possible. >> how long have you been working in respiratory physiology? >> since 1981 area.
>> and what exactly do you do the physiology? >> because i was going into this stage, i knew i had already spent five years doing lung disease and i wanted to know how you read and i wanted to come up with new knowledge because everybody calls everybody, and how to do a lot of new stuff. >> doctor, do you know of others in your appeals who have been studying respiratory physiology for 46 years? >> i know enough along the way but i would know no more than a handful or less of people who were still doing physiology at the patient's bedside. >> doctor, let's change up and talk a little bit about your experience or work as as
an expert. have you served as an expert witness before? >> yes i have. >> what type of cases. >> all been happening in medical malpractice so it's done for both the plaintiff, for the patient side and i've done for the defense, for the physician side . >> ever been involved in a criminal case. >> know, i've never been involved in a criminal case. >> have you testified in. >> identified in court, i don't keep track of the numbers but i suspect i've been in court about 50 times. >> would utilities and the gentleman if you're getting paid for your time in this case ? >> i am not getting paid. >> what is that. >> when i was asked to do the case, i thought i might have something, some knowledge that would be helpful to explain how mister floyd died and since i've never done
this type of work in this nature before, i decided i didn't need to be paid for. >> so did you volunteer tothe state of minnesota ordered the state of minnesota calling ? >> the state of minnesota contacted me. >> what were you asked to do. >> i was asked to review the medical records related to the case. these were medical records from in county and there were a number of interviews of people that were interviewed. i had seen them primarily and it was related to looking at a large number of different videos . and then of course the big part was i needed to read on the scientific background of all the areas that related. >> let's talk about your opinions with respect to this case. you formed an opinion to a reasonable degree of medical certainty on the cause of
mister floyd step ? >> yes i have. >> would you tell thatjury what the opinions are ? >> mister floyd died from a low level of oxygen. and this caused damage to his brain that we see it also caused a pda that caused his heart to stop. >> by pea you mean false electrical activity. >> correct, it's an abnormal beat of the heart arrhythmia a repeated format. >> is this what some persons might refer to as asphyxia. >> it has been called asphyxia. to me is not helpful, we're really talking about alow level of oxygen . people about hypoxia, that 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 reasonable degree of medical certainty at what the cause is or was for the low level of oxygen in mister floyd? >> yes i have. >> would you tell us what that is. >> because of the low level of oxygen was shallow breathing. small breasts. small title volumes, shallow breaths that weren't able to carry the air through his lungs down to these essential areas of the lungs that get oxygen into the blood and get rid of thecarbon dioxide . the alveoli at the bottom of the lungs . >> doctor tobin, using a short video that you prepare to help you explain to the jurors how oxygen gets into the lungs and the body?
i'm going to show you what's been marked as exhibit 950. can you describe first what that is? >> here we're looking at the lungs inside a body and we see here that you can see the windpipe off the top. the trachea and that splits from the bronchial tubes and also you can see the diaphragm down at the bottom and when the diaphragm and tracks, the air moves. >> the jurors can't see it yet. >> i'm terribly sorry. i apologize. >> exhibit 950. >> we can display soldiers can see. >> okay, now we're looking and you can see the contraction of the diaphragm area that's the pink area down at the bottom. with the air going down to the windpipe and then
proceeding down to the bronchial tubes. and then this was going to continue down the bronchial tubes onto the, to reach out to the air sac which will be the alveoli and now we're seeing that we're moving down here and these are like the gridlike structures down at the bottom and this is where all the action occurs . oxygen goes across those air sacs and also the co2 goes across and is expelled back out. that's everything in a very rapid video. >> so then what do you, what happened in the case of mister floyd relates to the shallow breathing that resulted in his lowoxygen . >> there are a number of forces that led to his, the size of his breath. became so small so there are the series of forces, higher up that are leaving to that. these forces that are going to lead to the shallow
breaths, are going to be that he's turned prone on the street. that he has the handcuffs in place combined with the street and that he has a knee on his neck and that he has me on his back on the side. all these four forces are ultimately going to result in the low title volume which is the shallow breaths that we saw here so the air will not be able to reach those air sacs we just saw in the video where the oxygen has exchanged and the carbon dioxide is removed. >> doctor, is there a concept in the respiratory medicine field known as. [inaudible] >> there is. >> out is that relate to mister floyd. >> if you look at the video all the way back until you saw those postures are, where you saw the blood vessels around the alveoli, everything to their.
so as your breathing in, your breathing through your nose, your mouth, down through your windpipe radiating out onto reach theair sac . once you get to the air sac all that space because the reason we call it is no oxygen can get acrossthose bronchial tubes . no carbon dioxide can get across. the oxygen and carbon dioxide, the only place that gets across his those rays like structures soeverything in the lungs before that . >> you mentioned several reasons for mister floyd's low oxygen and i just want to capture those for the jury. and then we will talk about them. you mentioned one handcuffs in the street. right? >> correct. >> you mentioned knee onthe neck .
sorry for my writing, you'll know i didn't get an a in school . the prone position. >> yes and then the knee on the back, arm inside. were those before? >> these are the four. >> we want to talk about the entities but before we do that, might it be helpful for explaining to the jury, for them to see the relative positioning of the various officers on mister floyd's body when hewas on the ground . >> i'veseen it . >> you can assist in preparing an illustration to show the relative position of the officers on the ground. >> yes i did. >> let me show you what'sbeen marked .
as exhibit 949. could you just tell us just described generally for the record what it is. >> i watched the videos and certain segments of the videos hundreds of times and is very difficult to get an overall view of where everybody is efficient because you are seeing different videos from different angles. so the artist has taken all the different videos here and he's combined them into one moment in time area and you can see here and also he will remove the, he's pedal so you're going to get a better view area that you're looking at a birds eye view of where mister floyd is lying and where the officers are positioned in relationship to mister floyd. >> so the purpose of this is to show the relative position
of the officers . >> your honor, we would offer exhibit 949 . >> 949 is received. >> so at what point in time did you say, you told us this is at a particular point in time. >> it's a particular point in time, i don't remember the exact minute, second off the top of my head. >> it's 8:21 and 44 seconds.
>> let's walk exhibit 949. the doctor can tell us what we're seeing. >> you can see the cards being rotated, you're able to see officer chauvin, officer king and lane. you see underneath mister floyd and other parts being rotated by the car, he's being removed and so you're able to see how their position to different points. in terms of with officer with his left knee on the neck, his right knee on mister floyd's arm and chest and then you can see here, officer lane holding his legs and then you can see officer king with his knee on his torso. >> this represents a snapshot in time as you told us. did the officers position change over time as they were there on the ground?
>> the officers positions change over time and also the position of mister floyd's themselves changed over time. these become relevant in how we evaluate everything. >> was it something you factored into your analysis? >> yes. >> did you consider what where mister chauvin business left knee was? >> yes, for officer chauvin, his left knee is on the back the vast majority of the time . >> when you say vast majority, are you able to -- >> more than 90 percent ofthe time. there's certain times it becomes difficult because you don't get a good view . for example, i know that in officer chauvin's right knee is on his back 57 percent of the time.
the reason i'm not able to say for the 14 percent is that i don't get a good view. other times, i don't have a good view of exactly where. >> did you focus on the first five minutes and two seconds? >> i focus on the first five minutes because that is up to the time that we see evidence of brain injury. >> so if mister chauvin's right knee was on his back from time to time, and other times it was placed where? in your observation? >> it was placed on his arm and then rammed in to mister 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
breathing, the effects are extremely similar. >> let's turn to the number one on the, yes. i mean in the back. so i wanted to turn back to the notes with the number one here written down for reasons you told us, floyd's low oxygen, mister floyd's low oxygen,handcuffed in the street . let's talk about the first one. >> could you first doctor tobin tell us how these various mechanisms, the four that you discussed, handcuffs in the street and kneeling on the neck in a prone position be knee on the neck, back, knee on the back, and side. out of 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 there directly related to my work in physiology. so in understanding the forces that the body had to cope with. these are crucial in terms of the various forces that involve pulmonology. >> turning to the first one, and guns inthe street . what is the effect of the handcuffs and the context of what happened to mister floyd . >> handcuffs are extremely important. the handcuffs on their own, handcuffs per se are not that important. it must be the handcuffs combined the street and it's because of the position of the handcuffs at the back and how he's manipulated with the handcuffs by both officer chauvin and by officer kueng, they manipulate the handcuffs
and they're pushing the handcuffs into his back and putting them high. then on the other side you have this street. so the street is playing a crucial part because he's against hard asphalt street. so the way they're pushing down on these handcuffs combined with the street is less left-sided it's particularly the left sideyou see that. it's like the left side is in a vice . totally being pushed in, squeezed in from each side from the street, at the bottom and then from the way that the handcuffs are manipulated not just the handcuffs, is how the handcuffs are being held, how they're being pushed. where there being pushed. that and totally interferes with essential features of how we breathe. >> so mister floyd and is handcuffed between the
pavement and forth on top of him. >> precisely. >> could you help us explain how this mechanism, the handcuffs and the street, how does that explain the shallow breathing that youdescribe ? >> this gets back to how we breathe. and this is fairly simple. so the way we breathe, we have two big muscles that help us with breathing we have the diaphragm, and we had the rib cage . the diaphragm does about 70 percent of what we need for breathing. about 30 percent of it comes from the rib cage. and there's when the diaphragm contracts for the repaid contracts, it expands the chest and when you expand the chest, then airflows in from outside coming in. and that's notall that happens on the inspiration but to expand the chest , there's two crucial actions that have to happen.
and we've referred to these by the term pump handle and bucket head. so if bucket handle is, if you have a regular bucket head, you carry water with and you lift up the handle of the bucket, the handle comes up. you can distract your diaphragm, you are performing a bucket handle movement on the rib cage. so you can track your diaphragm like that and each time as you inspire, you can see yourself. you see that your red cage is going out to reflect that. that's the bucket handle movement. the secondhand the second movement that you have is called the pump handle and this reflects to an old water pump that would be in the arm , pumping out water. so you have a handle at the top of the pump and you lift up the handle each time the
water comes out the spout at the bottom so you're filling up to get your container of water. with that action you're lifting up and it refers to the front to back movement of the chest from so with the pump handle, your chest goes out with each breath. 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 what your pump handle is. 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 side to side and that's with your bucket handle so both of these are required. without these you can't breathe. if you don't have the pump handle working, there's no air going to get in there. >> do you have a photograph
you brought that would help you understand the pumphandle and bucket handle ? let me show you what's been marked as state exhibit 951 . >> do you understand what this photograph depicts? >> yes. >> is it an accurateportrayal of a certain incident ? >> yes. >> would it help you explain the testimony? >> yes. this is an event that happened in england. >> one moment. i need tooffer soup your honor. we offer exhibit 951 . >> i have an objection to this your honor.
>> doctor, in this case were you able to observe whether mister floyd's breathing was impacted by the handcuffs and placement on the street ? >> yes i was. >> what did you observe? >> what i observed is in terms of the hands of the police and handcuffs. particularly on the left side as they were forcing his left wrist up into his chest, forcing it in tight against his chest, forcing it high up . you have to keep in mind that the opposite side of this is achieved so he was being squashed to the two sides. so this meant that he couldn't exert his pump handle. 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 in on the back, there was no way he could do any front to back movement. because of the knee that was rammed in against the left side of his chest, sometimes the knee was down on the arm or pinned against the chest. this would have the same effect. basically, on the left side of his lung, it was almost like a surge in activity. it was asif a surgeon had gone in and removed the long . 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. so he was going to be totally dependent on what he be able to do withthe right side .
>> have you selected any footage from the body worn camera that you feel that picsmister floyd's struggles to a degree . >> yes. >> i'm going to show you what's been marked as state exhibit 944. first, would you describe what it is . >> what you're seeing here is on the -- >> the jurors are seeing yet. >> i'm sorry. they will not see this, i'm describingwhat i'm seeing . that's fine. what i'm seeing is that his left hand is being grabbed by the police officers, so that's handcuffed left hand and is being pushed into his chest, so he's just not able to expand that. in addition what i'm seeing -- i apologize.
my misunderstanding. >> your honor, we sustain 944. >> 944 is sustained. >> now back to telling the jurors what you can see . it's quite all right. you tell us what the significance. >> you're able to see here with the yellow able error , you're able to see that the officer is holding mister floyd's left-hand. he's holding it very firmly. there's a firm grasp on it. and then mister floyd's left-hand is being pushed in against his chest. also, to see just on the side that officer chauvin need is coming in and that's compressing in against his side as well . so the ability to expand his left side here is inordinately impaired. and also, you're seeing that the size of the chain between the two, the right side and
left side is very sharp. so he is his whole left arm is also being pulled over and so is preventing him also from expanding the right side. i've been focusing on the bucket handle 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 is entirely in a sense seen here in one sense is that street. the street is why ishaving a huge effect . his kneecap down against the street so this street is playing a major role. in preventing him from expanding his chest. >> if you can clear the screen. >>.
>> did you select another still image that you observed as mister floyd struggled to read ? >> yes. >> i'm going to show youthe 942 . if you could just identify it . >> identified. >> do you recognize that the still image that you selected . >> yes i do. >> we honor state exhibit922 . >> 922 is received. >> could you tell us doctor tobin, what's the significance of this image and what we see here? >> what you're seeing is slightly different on the two images but they married together . you if you look, on the left side you see is finger, is
pushing against his street. the street. you also see the hands year of the officers around his left hand. you can see the left hand.arm as we discussed, you're seeing a more clearview here , where it's really being rammed into the back of his back. there's just no way he'sgoing to be able to expire there . with this, the left image you see the finger on the street. and over on the right image you see his knuckle against the tire. and to most people this doesn't look terribly significant from a physiology standpoint this is extraordinarily significant because this tells you that he has used up, his resources and is now literally trying to breathe with his fingers and knuckles. because when you begin to breathe, you begin to breathe with your rib cage and your
diaphragm area the next thing you recruit after that is your starting which is the big muscle in your neck. and then when those are wasted up, then you're relying on these types of muscles like your fingers, to try andstabilize her whole right side . because he's totally dependent on getting air into the right side. so he's using his fingers and his knuckles against the street to try and crank up the right side of his chest. this is his only way to try and get air to the right long . >> doctor, showing with and marked as exhibit 938 . is this a related series of photographs and images? >> your honor, we offer state exhibit 938 . >> objection. 938 is received.
>> tell us what we see here in exhibit 938. >> the focus would be, thetop panel is the same at the bottom one . the bottom is just a blowup of what you'reseeing on the top . the focus on the left hand side is his shoulder. and again, as i mentioned, when you have difficulty breathing you begin with the diaphragm, the rib cage and you go on tothe accessory muscles . one of the very last muscles that you will use is your shoulder. you don't really use your shoulder for reading but if you look here on the lefthand side , the shoulder is extremely prominent so this is would be what people in the gym would call sculpting of the shoulder muscles and you're seeing them standing out very prominently so at this point on the left-hand side, he's taking a breath in . using his shoulder to try and get a breath in then on the
right, you see to the breath where is relaxing is breathing and the two emotions as you see a marked effect on the left but again you have to realize that the shoulder is a very ineffective way of reading because at that stage , the chest is also expanded when you contract your shoulder, because the chest underline is so expanded, it gets very little air area is a very poor way of breathing. but it's what you have to do when everything else is failing. when you're in extremist, you will call on the use of the shoulder to try and read. >> doctor tobin, have we covered the first item , that his aunt on the street? let's talk about the number two. the knee on the next.
explain why many on the is so significant. >> the knee on the neck is important because it went to occlude the air getting in through the passageway. >>. >> is it possible doctor to perhaps even demonstrate with the lesson what may be relevant. >> to understand the under neck, you need to examine your own neck, all of you in the jury like i'm doing now reopened the first thing is if you put your index and paul appear at the top of your neck, the first big think they're going to find is your adam's apple. then you can find adam's apple and it's a sturdy structure because it surrounded by cartilage and it protects the voicebox, the larynx which is essential to speech. so any amount of compression on the adam's apple is not
going to compress it. this is an extremely strong, sturdy structure. it's not going to be compressed by the need for the neck . you go down from your adam's apple and you feel about many . these are the rings of cartilage on your trachea so this is your windpipe here. that's again, because of the cartilage there and the knee on the front of that part is not going to cause compression. but then bring your finger up to the top of your adam's apple. up at the top of the adam's apple you are now directly over the height and the hypopharynx is the crucial area so this is where the hyper larynx is located on yourservice anatomy . >> why is the hypo larynx
important for understanding this case. >> hypopharynx is very important for understanding this case a number of reasons . because it's so vulnerable, because it has no cartilage around it, it's going to be in an area thatis compressed . it's extremely small to read through. and it becomes very important or being able to continue to breathe through. >> doctor, i want to show you what's been marked as state exhibit 935 937 . could you identify just for the record, thomas what is depicted. >> i'm looking at 937 which is the hypopharynx. >> there we go. >> at 935. >> i'm looking at935 which is the hypopharynx . >> to these two images,
fairly and accurately depict bible ferrets. >> offer state exhibit 935937 . >> 935 and 937 are received. >> would you show them to the jury. >> doctor, using exhibit 937 and 935, could you help us to better understand what bible ferrets is and what it does. >> so what you're looking at here, this works? here where i've drawn in red is the top of your tongue. that's the tongue there and then a is an empty space and then that is the top of the heart, so that orientation there. then the tongue comes down along here the critical structure in this case because the act of speech in this circle becomes very important.
how you speak at all these different things so this doctor that uses speech or the vocal cords right here. they're in the voicebox and in the larynx. and then we have a little area here called the epiglottis which is a sliver and that comes back to prevent food going the wrong way when you're swallowing because we use the hypopharynx and for reading so when we're breathing, the end air is going to go in through your nose and godown through the hypopharynx , then to the vocal cords and into the windpipe into the trachea and go on down into the lungs. whereas when you're swallowing, that trapdoor of the epiglottis will prevent the food going into the air passages and redirected into the food to at the back of the esophagus. the area of the hypopharynx then is exactly from the base
of the epiglottis. the first yellow down to the second yellow which is the larynx and it's just that little area that is the science of the hypopharynx. we know that the cross-section of air in the area of the hypopharynx, i have it here in 199 to 303 which are obviously difficult to remember but in fact in the middle of this would be the sides of the time so the dime is basically the size of what the hypopharynx and it tells you how small and how vulnerable it is as an area so it's going to decrease in size. >> ..
in addition, hyperbaric's has another aspect, the hypo fair next is also controlled by the size of your home. as your lungs expand, you increase the size of the hypo fedex. there's a regulation going on. >> was mr. chauvin applying pressure there? >> audit different time, different time to time. >> are you able to tell us, was mr. chauvin previously, directly putting his whole weight on mr. floyd neck, are you able to tell us what impact or effect that would have had on the deployed? >> mr. chauvin place his knee
directly on the hypopharynx, then it would have and it never buried from the and it was like a bull's-eye on that particular area then you would expect the area would be he buried the position mr. floyd buried, the position of his head and officer chauvin. the position of his knee so it buried overtime. >> if it had become totally included, then what? >> within seconds, you're going to drop the level of oxygen to a level that would have oxygen deprivation resulting in a seizure or heart defect. >> do have another photograph from footage at the scene so we can understand this?
>> yes. >> exhibit 941. >> already in evidence. you recognize this photograph. >> i do. >> exhibit 941. >> tell the ladies and gentlemen of the jury what is the need to convey here, exhibit 941. >> if you're looking, the one on the left. if you stick your finger in your ear and draw a line going down through the body in your spinal column, you can get a line going down and you are looking at that. that's what i have drawn here on
the dotted line. so if you look here on the first, you see mr. floyd knows face is directly down, not at an angle. the next thing, don't look at this, see yourself on your own neck and if you put your hand at the back of your neck and you put your fingers at the bottom of your school, then come down and you put your whole hand around -- >> i'm sorry -- [inaudible] [silence]
certain things, these are not required. recent more in terms of if you were to do that and if you wish to do that. you're not required to do anything you are instructed to do but feel free if you wish. >> if we could go back to where you explain the anatomy in the back of the base of the school. >> since i put my hand here at the back of my neck and feel the tip of my school and bring down the hand, you take ligaments and it's almost as i my hand on my ligaments, it's almost like wood, so strong a ligament. that's what you see the need being placed over on the next slide. with the knee directly over the
ligament, it can cause snow obstruction, such a dense ligament and that's what you're seeing and you see as well the yuck no yellow diagonal officer chauvin's knee is above the yellow line. the second thing separate from this side, you can see mr. floyd has his face rammed into the street because he's using his face here to try to crank up his trust, he's using his nose and chin as a way to help him get there into his chest. >> how do you contrast to what we see in the photograph on the right. >> on the right-hand side, you can see orientation of mr. floyd has changed and also you can see
the position of officer chauvin tammy changed because it's come down below the yellow diagonal. in this position it's going to be far greater compression of the hypopharynx in this region here compared to what you're seeing on the left side. the left side, no compassion of the hypopharynx but on the right side, if you watch the video over time, you see a variation over time as to where exactly is the location of mr. floyd had and where the location of officer chauvin snee. >> the photograph on the right, then he is exerting greater force? >> correct. >> is a popsicle to calculate the amount of force? the market is. >> we can calculate based on the
weight of officer chauvin's, his body weight taking into account how much weight, figure he carries and you have to remove out the weight of his shinbone and his boot so subtract that all and then you can calculate the weight. >> you also calculate the changes when narrowing the space people have to breathe through. >> yes, separately. >> would this be akin to breathing through a small opening like a straw? >> it would. when you breathe through a narrow passageway, it's like breathing through a drinking straw but much worse, breathing through a drinking straw is somewhat pleasant but not that
unpleasant and then it gets much worse. >> as the space narrows, is it more difficult than to breathe through? >> enormously more difficult. >> to physics then is that something that can also be calculated? >> yes. >> that type of calculation, would it be specific to george floyd? >> it wouldn't, it would be for anybody, we know in terms of what happens when you have this level of narrowing, this will happen to anyone. >> can you explain to the jury what the calculations would show about the area? the airway on breathing? >> yes. i believe this exhibit displays that. >> let me show you exhibit 940 and 939.
effort to brief, that's what's shown around the y axis of the plot and then different levels of narrowing the bottom one would be the lowest curve, that's normal, no narrowing. we see the flow theories shown in red is the normal flow rate and a 46-year-old man we can see the work that's done. if you look at the normal one and then 60% airway narrowing in this is much more narrow than breathing through a straw, you can see there is no bigger increase, it is hardly different in terms of normal but then if you get 85% narrowing, now you see the effort to brief increases seven and a half times compared to no narrowing so you
are seeing a huge increase in the work, it's far more difficult to breathe as the narrowing becomes more narrow. >> let's look at exhibit 939. >> it's behind, this is just the equation in physics that tells you how that works. when you look at an equation like this for me as a physiologist, i focus on the square side that tells me here, the sign on top and it's below the level on the equation it is, the nominator. i know with that but you're going to be fine for a period of time but then suddenly everything increases enormously, and exponentially increase and
that's exactly what we see on the experiment that was done. there's nothing happening here but then at 85%, it suddenly takes off and if you have beyond 85%, it's even more so based on the formula here, as you are narrowing and narrowing, the effort to breathe is going to become extraordinary high end at some stage, unsustainable, you just can't. >> in this case, the case of mr. floyd, the narrowing was his hypopharynx? >> yes. >> did mr. chauvin snee on the neck and caused the narrowing. >> it did. >> so given the changes as you observed on mr. chauvin snee,
mr. floyd, over time, or any of the changes significant from placing pressure on the hypopharynx? >> yes. >> let's look at exhibit 947. we offer exhibit 947 taken from exhibit 15. >> received. >> tell us what we see here in exhibit 947. >> the orientation of officer chauvin, is button his erect here but what you're seeing is the toe of his boot is no longer touching the ground.
this means all of his body weight is being directed down at mr. floyd neck because in many calculations i excluded the effect of his leg and shoot because some of it was touching the ground but here you can see none of it touching the ground so we are taking half his body weight plus the weight of his gear and all of that directly down on mr. floyd neck. >> going to show you exhibit 943, did you assist in this exhibit? >> yes, i did. >> would help you to explain? >> yes. >> we offer exhibit 943.
>> 943 is received. >> we are the screen. thank you. what we see here in exhibit 943? >> half of his body weight plus half your weight is coming down directly on mr. floyd neck. >> is that all we see? >> the reason we see that is because the toe is off the ground and there's no body weight, he's not hunkering back on his knee so everything is directed down on his knee. his shin and his toe and his boot. >> were there times also when mr. chauvin left me on the back. >> correct. >> when was that?
>> when his knee is on the back, that's different force, same force but compressing a different area, inside his chest. >> what about the time when mr. floyd had his face smashed directly into the pavement? >> when his face is into the pavement about time, like the ones i've showed you, coming down on the ligaments, it's going to be a huge wait for mr. floyd to try to brief but he won't be compressing the hypo bearings at the time that's happening so all of these different forces are somewhat complex. >> you paid particular attention, you told us in the first five minutes and three seconds on the ground? >> yes. >> how would you characterize mr. floyd's oxygen levels during the first five minutes mr.
chauvin was on top of him? >> we know his oxygen levels were enough to keep his brain alive and the reason we know that is because he continued to speak over that time, we know he made various vocal sounds for four minutes and 51 seconds from the time the knee is placed on the neck and that's telling us partly, you can't speak without a brain being active so we know there's oxygen getting to his brain whenever he is making an attempt to speak. [silence]
[background noises] >> you're still under oath. >> take off the mask? >> please. >> turn your attention to exhibit 943. focusing on restraint, your focus on the first five minutes and three seconds in particular mr. chauvin was applying weight to mr. floyd neck. >> correct. >> why was the time. after the first five minutes and three seconds less significant to you? >> because at that time where he extended leg we see happening, when we see that happening is at
2421, that's when he suffered brain injury, we can tell from the movement of his leg the level of oxygen is brain caused what we call myotonic seizure activity but basically that means he kicked out his leg and extension form, he straightened out his leg and that's something we see in patients when they suffer brain injury as a result of a lower level of oxygen. >> we will talk about that more in a moment but is it significant to you whether mr. chauvin moved his knee mr. floyd neck after mr. floyd was unconscious? >> no, the movement happens around a different time,
obviously the key thing is everything up to the time we see the brain injury occurring, where officer chauvin moved his knee after that really is not going to have impact. >> would you help the jury understand that if mr. chauvin is applying pressure on the side of the neck and as we see exhibit 943, how does it translate to narrowing of the hypopharynx? >> it's going to depend on what is the orientation of officer chauvin body, what is the orientation of his leg and in particular, the orientation of mr. floyd, where exactly is the orientation of mr. floyd had because of the ligaments under
officer chauvin's knee, there's going to be compression of the hypo bearings that if it moves to the side and officer chauvin's weight coming down on the side of mr. floyd neck and you get huge compression of the hypopharynx. >> looking at exhibit 943 and focusing on the first five minutes, was his knee overarching of the side or back. >> for the first five minutes, the left knee is on the neck virtually all the time. the right knee by my calculation, the right knee is on his back 57% of the time. the reason i can't say it's one 100% most of the other time i don't get a good view, the cameras move around but for that
period of time, the crucial period of time, the five minutes and three seconds, i can see officer chauvin's knee on his back for over 57%. >> let's talk about the third mechanism, the prone position. mr. floyd being placed in prone position also have an impact on the narrowing of the hypo bearings? >> yes. particularly also causes narrowing of the hypopharynx. among other things. >> is there a concept of physiology referred to as long file? >> yes. >> what is that? >> that's the way lung specialist measure the size of the long in different patients and quantify different areas,
what level of the long there is, whether it's different segments of the lung. >> you have an illustration to help us better understand this. >> yes. >> i'm going to show you exhibit 929 and have you first identify it. >> i identify 929. >> what is it? >> shows lung function. >> is connect with lustration? >> yes. >> i offer exhibit 929. >> received. >> until we get started --
>> dry go ahead and describe? and guess. [inaudible] >> don't talk over each other, we are getting into that bad habit. ask the question again. >> thank you. i'm going to ask if you would explain to us what we see in exhibit 929. >> we are looking here at the lung inside the chest, the chest is gray and the long is inside, surrounding the space and we are seeing as you look at breast going in and out, it generates the volume shown as a form at the bottom so that's what happens in somebody with regular breathing. >> see if we can get is to tie. >> here you can see the chest
expanding like on the front you see the action of the chest and with each breath you see air going into the lung and it reduces the breath. exhalation is going back. >> is there a standard or normal size of breath? >> yes, virtually all adults, it's about 400 cc. >> same for men and women? >> same for men and women and for teens and grandparents. >> and lung volumes calculated? >> you can calculate further additional lung information. >> did you do a calculation for mr. floyd and volume? >> yes, i calculated precisely based on his age, sex