 As Askan said, I'm Colleen Walrab and I'm the lab manager at the Float Clinic and Research Center in Tulsa, Oklahoma under the direction of Dr. Justin Feinstein. And today I'm going to be talking about how we actually came to be able to measure physiological effects of floating in this really challenging environment and actually present on some of our preliminary data. So just some background on the topic and why it's really important that we measure this to begin with. So right now in the United States there's an epidemic of chronic stress-related illness. And psychological stress has been shown to be implicated in chronic diseases like cardiovascular disease, adult onset diabetes, as well as even early death. So this is actually what got me really interested in studying flotation, something called the relaxation response. And this can be defined as a state of decreased sympathetic nervous activity or inversely a state of increased parasympathetic nervous activity. So now I'm going to go through some of the past float research that's been done using physiological devices. So to start off, there's been a great body of work on blood pressure, primarily with normative intensive populations, so people with healthy levels of blood pressure. And throughout the course of several floats, participants in these studies were seen to have longitudinal reductions in both systolic and diastolic blood pressure. And there's even been some work with hypertensive populations, so people with elevated blood pressure. And for these studies, Tom Fine and John Turner worked in the early to mid-80s with these hypertensive folks. And they had them float for a series of weeks, about once a week, and then once they were done floating four months later, they measured their blood pressure again, and it remained at a normative intensive level. So this was really interesting, and I think that we need to replicate this. We actually definitely need to replicate this, because it was done in a relatively small sample size, so it would be interesting to see at a larger sample size what effects we might find. And I should add as well, this was done before the invention of blood pressure medication, so it really was novel and important work. All right. So there has been work with heart rate done as well, and this is basically how many times your heart beats per minute. And most of this work has was done measuring heart rate or blood pressure before the float, and then after the float. And there were some pre-post reductions in heart rate shown as well. And another important variable that was measured back in the 80s and early 90s was plasma cortisol. So cortisol is a stress hormone, so we can see one might be interested in measuring it in the float environment. And Tom Fine and John Turner, so significant reductions in plasma cortisol throughout a series of floats. They had subjects float several times, and from the beginning of the study to the end of the study, significant reductions in cortisol were seen in the blood. And while this is a really great place to start, there's a lot of work that needs to be done. So there's several unknowns, such as what things look like continuously throughout the float. So the temporal dynamics, how blood pressure, heart rate, breathing rate, all these variables change throughout a float and during a float session. So no studies have even begun to examine breathing rate or any other respiratory parameters during a float. And as well as no studies have yet to examine body movement or how accelerometry or basically how much someone is moving during a float might impact the degree of clinical effectiveness or basically how effective the float is. Now I'm going to show you just how difficult it was for researchers like Tom Fine to measure these variables back in the day. So to measure blood pressure, they literally had to drill a hole in the side of the tank. And that's actually Tom Fine in the tank there and his colleague John Turner measuring his blood pressure. So at the end of the float, they had to have the participant stick their arm out and say, all right, get ready, we're going to take your blood pressure, like stick out of this hole in the side of the tank. So we're really lucky at the Laureate Institute. We don't have to do this anymore. We have wireless technology that enables us to measure blood pressure without having to drill a hole in the side of a float tank. And in fact, we couldn't have even done this five years ago because of the advances in wireless technology. So we're really lucky in 2016 that technology advanced to the point. We're able to measure all these variables. So now I'm going to go through what we actually are able to measure. We're able to measure breathing rate using impedance on a device on the chest. So we don't even have to use a respiratory belt. So it's very non-invasive, actually. We're continuously able to measure heart rate and heart rate variability through EKG posture. Basically we can see when the subject lies down, sits up, stands up, and basically track their movement throughout using accelerometry. We're also able to measure blood pressure continuously using wireless Bluetooth technology. And lastly, EEG brainwaves, and Dr. Ricardo Gildecosta will be presenting on that data tomorrow. So this is a cartoon of what it looks like to float in one of our float pools. You can see the EEG on the forehead, the device measuring EKG and respiration rate on the chest, and then the blood pressure cuff on the arm. And it's really important that we do these four things for all of our devices. They have to be waterproof, salt-proof, wireless, and non-invasive. That's our four criteria for any device that we have to use. All right. And to do those four things, it wasn't easy, and it continues to be a challenge every day. So we've had quite a bit of trials and tribulations to get to where we are now. So for instance, waterproofing the devices is really difficult, because these are electric devices in a saltwater environment. So we need to make sure they're completely waterproof, mostly so we can get clean data and actually look at the results. So we have to use Tegaderm film to cover the devices. Basically, Tegaderm is something that's used in hospitals to cover wounds or medical devices. And Bluetooth connectivity continues to be an issue, because we work in a brick building. So getting all these devices on the same Bluetooth signal, not interfering with one another, or really just connecting it all, continues to be challenging, as well as time sinking all the devices. So we want to make sure that the EKG, the respiration rate, the EEG, the blood pressure, they're all in the same time sequence that we can look really precisely at the data and see how these variables overlap and interact with each other. We also want to ensure, once again, that all the devices are minimally invasive, waterproof, and salt-proof. And this could absolutely not have been done without these three gentlemen, our electrical engineers, Will Schoenholz, Jesse Shetler, and Obata Alzubi. So we actually had to hire a team of graduate students, electrical engineers, to get this job done. And in fact, the guy in the middle, Jesse Shetler, did his entire master's thesis on this topic. So they were really integral and continue to be integral in this process. And now, this is a video of what it looks like to actually float with all of our devices on. So you can see the EEG on the forehead there, the blood pressure cuff, we have a waterproof cast that we use, and the device that measures both respiration rate and EKG, as well as on his wrist there, you can see watches that measure accelerometry, or basically how much he moves during the float. This is in our open pool, so it's really easy for the subjects to get in and out, and it's a nice comfortable first float experience. You can see how lightweight and small the devices are as well. Now I'm going to actually show you some plots of different measurements that we've been doing in some pilot testing. So just bear in mind this isn't a small sample size of our pilot testing, so no real generalizations can be drawn. I think we are seeing some evidence of a relaxation response in the float environment. So first up is heart rate, and this was a sample of seven healthy people, both physically and mentally healthy, and they floated 44 times in total, 34, rather times in total. And you can see these were 90-minute floats, and on the y-axis here, you can see the heart rate. So we did about three minutes of baseline measurements before they actually got into the pool, and around there, their heart rate averaged about 95 to 100 beats per minute, and then really precipitously dropped down to about 70 beats per minute and stayed there throughout the course of the float, and then once again rose after they exited the pool. All right, now I'm going to move on to some blood pressure data, and this was once again the same seven healthy subjects over the course of 25 floats. So just some background and systolic blood pressure. This is basically when your heart is beating at its peak and your ventricles are contracting. So you can see at baseline, our subjects averaged about 125, 130 millimeters of mercury for their systolic blood pressure, and then it dropped to about 115 when the subjects got into the pool, and then at its minimum was about 110 millimeters of mercury, and then continued to rise back up towards the end of the session, and then went back to baseline after they exited the pool. Once again, these were 90 minute floats. The next step is diastolic blood pressure and the same seven healthy subjects over the same 25 floats. So diastolic blood pressure is when your heart is beating at a minimum. So this is when your ventricles actually fill with blood. So it's basically your resting blood pressure and perhaps of most interest to us. So you can see before the subjects got in the pool, their diastolic blood pressure started about 80 millimeters of mercury, and then really quickly dropped down to about 65 millimeters of mercury, and then throughout the course of the float continued to fall down to about 60 millimeters of mercury, which is actually quite low, and then rose back up once they exited the pool. So another interesting point of comparison is the diastolic blood pressure in our float chair and our float pool. So Justin and Pawn spoke earlier today about our zero gravity floatation chair, so I'm sure you all are familiar with that already, but I just wanted to show you some comparisons between the two in terms of blood pressure. So the subjects floated 13 floats total in the chair, and then there were 25 floats once again in the pool. And you can see at baseline on both before the float and after the float was over, the diastolic blood pressure in both conditions were about the same. So these people were about the same at rest, but then when they got in the float pool, it was continuously lower in the pool than it was just in the chair. So that was interesting, as well as you can see it continues to fall even deeper in the pool than it did in the chair. So it stayed pretty stable in the chair, but the graph of the pool shows that it just continued to go lower and lower throughout the float session. And now I want to wrap up with some future directions for the lab in terms of physiological measurements. So just like I was just speaking about with the floatation chair, we want to see how floating in the pool might be systematically different than other forms of simple relaxation. So we'll continue to use our zero gravity chair or other control conditions to make sure that floating in the pool really is more profound physiologically than other forms of relaxation. Another variable of interest for the future is heart rate variability. So this is basically your body's or your heart's way that it adapts to both the external and internal environment of your body. So basically the higher heart rate variability, the better. And we're hoping to see maybe that in the pool, your heart rate variability might increase. And also it's really important that we measure how the physiological relaxation might persevere beyond the float environment. So after someone's done floating for a period of time, we'll go ahead and measure them after they're done floating with the experiment to see if they've learned to relax outside of the float environment. So we'll teach them to relax in the float pool, but then it'll be interesting to see if they've learned to relax outside of the float pool. And lastly and perhaps most importantly, we're interested in working with clinical populations and seeing how this might affect them physiologically. So people who suffer from anxiety-based disorders like PTSD and fittingly up next is Dr. Saab Khalsa, who's going to be presenting on some preliminary data with women who suffer from anorexia nervosa. And thank you very much for your time today and listening to me.