Episode Transcript
Biofeedback and Heart Rate Variability with Rohan Dixit
[00:00:00] Jill Brook: Hello fellow POTS patients and beautiful people who care about POTS patients. I'm Jill Brook, your hyper adrenergic host, and today we are speaking to someone with a pretty interesting story who invented some technology to help people gain better control of their sympathetic versus parasympathetic tone.
Rohan Dixit is the CEO and founder of Lief Therapeutics, which uses wearable devices to help monitor and improve heart rate variability. Rohan was formerly a Harvard and Stanford neuroscientist, but is now an entrepreneur. His work has been featured on the Today Show, NBC, CBS, the Atlantic, Forbe magazine all over the place.
And today he's gonna help us understand heart rate variability, what it is, why we should care, how we might go about improving it, and all that good stuff. Rohan, thank you so much for joining us today.
[00:00:55] Rohan: It's such a pleasure to be here, Jill. Thank you.
[00:00:57] Jill Brook: So do you mind starting by telling us a little bit more of your backstory and how you became interested in this space?
I mean, POTS patients of course, are very interested in sympathetic versus parasympathetic tone, but it's something that everybody ought to be interested in and I don't know if we've talked about it enough. So do you mind just kind of telling us how you got in the space?
[00:01:18] Rohan: Yeah, so the autonomic nervous system, of course, is of interest to people with POTS but it also has a lot of correlations with mental health, and that was actually my avenue.
I struggled with anxiety and depression as a teenager and started doing practices, which I realized years and years later were affecting my autonomic nervous system. And that's how I was feeling better. So that was my initial entry point into it actually.
[00:01:43] Jill Brook: Okay. And it's so great that you realize that not everything about the autonomic nervous system is about stress or anxiety or depression. It can be, but I know that in the POTS world, a lot of POTS patients get misdiagnosed as purely anxiety for a long time because so many people don't recognize that there's different ways to get there.
[00:02:03] Rohan: That's right. That's right. These systems are all interconnected, you know, and that helps understand it's such a new thing.
[00:02:09] Jill Brook: Yeah. Okay, so can you tell us what is heart rate variability?
[00:02:16] Rohan: So in a nutshell, heart rate variability is literally the timing differences from one heartbeat to the next. Small milliseconds of timing difference.
And the more variability, the more variation between one heartbeat and the following heartbeat. For example, let's say 60 beats per minute, your next heartbeat might be 65, the next one might be 63. Those changes are literally what's known as heart rate variability, and it can be measured in different ways.
[00:02:40] Jill Brook: So I think a lot of people would be surprised that their heart rate isn't steady and that it's actually a good thing, the less steady it is. But is that what you're saying?
[00:02:50] Rohan: It's such a counterintuitive thing and a lot of physicians especially, you know, over the last five years, heart rate variability in the autonomic nervous system have become more mainstream.
And so the world is catching up and so is medicine. But I think oftentimes people are surprised but if you have a very steady heartbeat with no variability, that's typically a very dangerous signal. Your body is in an extreme state of dysregulation. And so, so what we want actually, typically, in most cases, almost all cases, is to have more variability in our heart rate. It's a sign of health.
[00:03:22] Jill Brook: Okay. And so just to drive this point home, you're not even talking about a steady heart rate when you go from sitting to walking or something like that. You mean just sitting there, not changing your physical activity, not changing anything. Your heart rate is still variable in that condition in a healthy person, ideally, right.
[00:03:41] Rohan: That's exactly right. It's bouncing up and down all the time. And that, that variability is almost like flexibility. It's as a metaphor that's used oftentimes. It lets you respond to different types of stressors in your life and, and, you know, be able to adapt to them.
[00:03:55] Jill Brook: Okay, so tell us more about what it actually means.
What is high heart rate variability mean? When do we get that and what does low mean and when do we tend to get that? Because everybody varies, right? Everybody goes up and down to some extent.
[00:04:08] Rohan: That's right. We're always varying and we're even varying within, you know, short periods of time, within an hour.
I focus a lot of my work on heart rate variability with mental health and, you know, when we are looking at heart rate variability changes and I'm just looking at my own data It can change from, you know, one conversation to the next. And we all know that our mind and how we feel can be very variable.
And so that's reflected actually in the autonomic nervous system. There's some deep ties with our emotional state in the autonomic nervous system, just like there are deep ties with physical health conditions as well. And that's the natural variability that tends to happen with these signals.
And what's interesting is that you can learn how to actually improve them over time and, and change them in directions that might be more advantageous depending on where you're starting and where you might want to go.
[00:04:52] Jill Brook: So one thing that's been interesting to me, I know that the Apple Watch has a heart rate variability measure, and I know that it's not the best and it's not that accurate compared to what you do.
But it was interesting to me to see that I vary quite a bit but I'm worse than my husband. And that kind of makes sense because I have POTS and I'm a higher anxiety person and he does not have POTS and he's a super laid back person. But he recently got COVID. And I could not believe when he got COVID, how low his heart rate variability went.
And I took that as a sign that that was really a big stressor to his body. Is that accurate?
[00:05:30] Rohan: Yeah. I mean this is all new research, but what we saw even from the beginning of the pandemic was low HRV was a diagnostic indicator of getting COVID 19. And you might actually notice a low HRV sooner than you notice any symptoms in a lot of cases.
And so that's how it was being used initially. And then of course, the whole long COVID aftermath that's we're still living with today where there's decreased HRV and all the hosts of problems that go along with that. And all these questions of why it is that we have this huge pandemic now of dysautonomia and POTS and also mental health concerns after COVID 19 infections, I think again, we're talking about perhaps the autonomic nervous system and the role it has to play in our health, you know?
[00:06:13] Jill Brook: And then I think there's even one other angle where I've seen a lot of people using heart rate variability, and that is in serious athletics. So, since I do nutrition work, I've worked with a bunch of teams and what I've seen them do is look at their heart rate variability to see when they might be over training versus when are they due for another really tough workout. Are you aware of people using it that way?
[00:06:39] Rohan: Yeah, and we have some of our customers use it in that way as well to biohackers, particularly I think in general, the the understanding that we have as a scientific field and as an industry, is that there are maybe bands of HRV ranges in which you wanna typically stay and when you're too low or too high, you wanna probably take note of that and make behavioral changes. You may wanna do other things to try to stay in a healthy range. And so yeah, athletes use it as well. Again, you know, similar to the stress that your husband's body went through when he contracted COVID, right.
You're also stressing your body when you're pushing it physically. And so you can measure that with HRV and you can actually see, well, I'm still not fully recovered. Let me not push myself too soon. And, you know, for some of our our users and patients with POTS and Dysautonomia particularly, that can be really helpful because you do wanna pace yourself to avoid, you know, potentially crashing.
[00:07:33] Jill Brook: Okay, so that's interesting that you can kind of see that. So in your experience, cuz I know that you've now tracked tons of people with their HRV. In general, can people learn to feel when they're in a state of low heart rate variability versus high heart rate variability? Or is it so subtle that you would see the numbers change but you wouldn't feel a difference yourself?
[00:07:56] Rohan: You know, everybody has a different ability to what's known as interocept to see and feel really what's happening inside your body and become consciously aware of it. It's always happening, right? I mean, our heart's always beating. We're always breathing. Sometimes you may have the experience of realizing in a stressful situation that you've been holding your breath and you didn't even really notice that.
Of course, that has been happening. Your body's been controlling that through your autonomic nervous system, but maybe you weren't fully aware of that actually happening. So typically with, you know, any tool, I, I think what can be helpful is it can give you a little bit of awareness in those moments where you may not have it.
And then over time you can use that almost like a little thread to kind of hold onto, grab onto and then pull in and then get the sensation sort of more familiarized, where then you can start to recognize states of low HRV and high HRV yourself. And so that's the beauty I think of, of biofeedback, which is an interesting technology in and of itself, and I think is potentially of use to the POTS community.
I know there's early stuff and work being done in that space, but I think that is actually really interesting to think about in terms of how one might utilize HRV and biofeedback to gain awareness of what's happening in their body in order to then, you know, shift it over time.
[00:09:13] Jill Brook: Okay, so before we just sort of leave this basic topic, I just wanna make sure everybody has sort of an easy way to grasp, is it oversimplifying to say that high heart rate variability equals parasympathetic tone or that rest and digest and that low heart rate variability equals the fight or flight or the sympathetic overdrive?
[00:09:35] Rohan: I think that's a useful simplification that is really common and it helps people understand what's going on, I think. Yeah. So I think that's totally fair and you know, Jill, just to be totally honest, I think that we are really in the beginning stages of understanding autonomic nervous system and, and the complexity of it.
Are there really only sort of two poles that the body moves between, or is it a more multi-dimensional system? Probably is a little more complicated than just that, but that's a great way to start thinking about it. Right.
[00:10:05] Jill Brook: Okay. Okay, cool. So tell us about what your device does and how it can tell us some stuff about heart rate variability.
[00:10:14] Rohan: Yeah, I'm an inventor. I invented this product, which is called The Lief, and it is an HRV biofeedback tool, which I invented for myself cuz I have anxiety, like I mentioned, and I really wanted to to feel better basically, and, and be more aware of my body and how it's affecting my mind and, and just live a happier, healthier life. So always been a tinkerer and kind of put together this tool, which now is an FDA class two device, and it's a patch.
You put it on your body, it's measuring your HRV, it's designed to measure HRV really accurately. What's interesting and kind of unique about it, and I know I've alluded to this a couple times, is this functionality has to do biofeedback. and biofeedback for those of your listeners who aren't familiar with biofeedback, maybe it's useful to have a short primer on what that term means.
So, biofeedback, you know, was this technology that was invented more than 50 years ago, and the initial experiments were around fingertip temperature. And what they did was ask people to either raise or lower the temperature of their fingertip using their mind. Which is impossible, obviously we have no conscious control over our fingertip temperature, but it turns out if you have an accurate sensor, digital thermometer, clip it on your finger and you're looking at it in real time. So it's two things. It's accurate and it's in real time. You can actually learn to consciously control your finger temperature up or down with your willpower.
That's biofeedback. Temperature, fingertip temperature is an autonomic nervous system function just like heart rate and heart rate variability. And similarly you can learn how to control your heart rate and heart rate variability as well through biofeedback. So that's really what Lief does, I think really well. We are quite accurate in measuring HRV, but the device will turn on when your HRV's low, it starts to vibrate, kind of mirrors back to you what your heart rate's doing and it helps you learn how to shift your HRV higher in the moment, you know?
[00:12:04] Jill Brook: Okay. So I know you originally designed it for people who do not have POTS. What is the intention of how to use it for someone with no POTS? What's kind of a classic use case?
[00:12:15] Rohan: Yeah. So typical kind of treatment plan for somebody, let's say with mild to moderate anxiety, that's a really common use case that I'm also familiar with. There are many other great biofeedback devices out there.
One of the things that also is a little is unique about how we have done biofeedback is we've created these sort of threshold triggers. Whereby you can sort of set where you want HRV biofeedback to turn on and off where you want to be alerted, let's say when your HRV is dropping relative to your typical, what does my body typically look like?
Right? And so a lot of the training protocols that we use for Lief are around understanding where somebody's threshold should be set at the beginning, middle, and late stages of training so that you can start to learn how to sense what's happening in your body, how it's affecting you, and also sort of not get overwhelmed and feel like you're winning and being able to learn how to change your HRV in real time and all this sort of thing over time, right?
So those are some of the treatment protocols, which will vary depending on whether somebody is coming in with mild anxiety or coming in with maybe a different type of chronic health condition. And, and those are dials that you can kind of tweak to suit how somebody feels and what's working for them or not.
[00:13:29] Jill Brook: So just to see if I understand correctly. So for example, if my particular heart rate variability numbers tend to go somewhere between say like 25 and 75, then it could kind of get to know that about me and it could kind of get to be saying where, okay, as soon as you cross a certain number, we're gonna vibrate and let you know that you are headed into a sympathetic state. And so we're gonna kind of remind you to do some biofeedback, and maybe that's breathing exercises or maybe that's something else. And you're gonna learn to get yourself back to, to kind of pull out of that.
[00:14:09] Rohan: That's exactly right. And, and then over time you can kind of make it harder and harder, more and more difficult and basically build that muscle autonomic training.
[00:14:17] Jill Brook: That's so interesting. so I guess that's what a lot of people are able to do through different means. People who meditate, for example, people who do all kinds of different things. Biofeedback is just one more skill. I have no experience with biofeedback, but when I hear about it, I'll tell you what I think about: I think about the time I learned to wiggle my ears because I just one day discovered this muscle and I was like, oh my goodness. I didn't know that muscle was there, but now, now that I found it, I can control it. And I'm one of those people now who can wiggle my ears and is biofeedback kinda the same?
[00:14:51] Rohan: It's super similar because, because you could always move your ears. The muscles were there, right? And it was just a matter of kind of becoming aware of them and learning like, oh, if I do this and I do that, and oh, it's kind of moving around and then you get better at it. And yeah. And that's the typical process with biofeedback cuz you're kinda like making something that's invisible, visible and you're learning how to play with it and, and control it. And that takes time. And it's like learning any new skill, like learning to play basketball or ice skate or whatever.
[00:15:17] Jill Brook: That's interesting. So, I don't know if you have insight into people's data, but do people basically learn to just spend less time in a sympathetic state?
[00:15:27] Rohan: Yeah. And so, I think the approach that we take is when you're dealing with anything that is related to autonomic nervous system dysfunction, you don't wanna, you know, I hesitate even to use the word dysfunction because we have a natural range of our bodies and, and that range is healthy, and you're not always in a high HRV state and you shouldn't always be in high HRV state. And so a lot of what we've done at Lief is trying to come up with ways to crunch all the data that was overwhelming to me trying to like really understand my own physiology and my own HRV numbers, and make it very simple, easy to understand, standardize across people and across, you know, your own self, right?
And so, we turn HRV into a simple color, you know, red to blue. It's always based on your own data. So it's kind of like learning your own physiology as you change and as you may go through ups and downs and it's giving you a baseline from where you're at. And yes, I think over time, you know, you may start to shift it higher particularly for, you know, conditions where low HRV is maybe not working in your favor. But a big part about, I think using any biofeedback tool and any monitoring tool, even simpler than a biofeedback tool, just a monitoring tool is awareness. And that awareness I think could be really helpful for people.
[00:16:48] Jill Brook: Yeah, for sure. So it sounds like when you originally designed this, it was largely to help people kind of change their emotional state in order to increase their heart rate variability.
And I think for somebody who does not have POTS, that emotional state is probably the biggest driver of that. Maybe along with what we said about exercise, whether you're, you know, over training or something. But in POTS, it's interesting to think that there's this whole additional disautonomia piece that can also be pressing on the heart rate variability.
And so things such as potentially like lack of oxygen to the brain or some of the things, you know, that extreme pain, some of those things that happen in POTS could probably be working on heart rate variability, independent of emotional state. And so I'm wondering, do you have any stories of POTS patients who use this and maybe they learn to do some things to change their emotional state, but they also have to learn maybe I'm guessing that laying down and putting my feet up in the air seems to always do good things for me, and I wonder is it the kind of thing where each particular patient can kind of learn what helps them get back to a desirable heart rate variability.
[00:18:10] Rohan: Yeah. You know, I'm thinking of one of our customers who ended up becoming a contributor on our team and found us because he had used a Lief in a very similar way where he was experiencing symptoms of POTS, of dysautonomia, and realized through using, you know, biofeedback trainer, basically one, a bunch of the triggers that he wasn't aware of initially.
Two, a variety of things that could help him feel better. Not just biofeedback, which is quite helpful I think in the moment. But also things like splashing cold water on your face, lying down when you need to, elevating your feet. There's a huge long list. I think it's, it's really interesting to use the data as a tool and a guide to help you understand your own triggers and, and maybe things that might be helping you as well.
[00:18:54] Jill Brook: I'm guessing some people have a little bit of humor in identifying their triggers, things that you didn't know were triggers. And it's hopefully, it's like not your children or your spouse or your boss, but I'm guessing that sometimes people learn about triggers that they hadn't been consciously aware of.
[00:19:09] Rohan: Yeah. Yeah. I mean, types of foods, there's all kinds of things that sometimes are just below your level of conscious awareness, but when you start measuring it, you can say, oh, yeah, well that, I guess that did have an effect. Maybe let me switch my routine a little bit tomorrow. And it's, I think those 1% changes in lifestyle that can add up over time, particularly with a chronic illness, you're in this for the long haul and so how can I sort of like maximize my healthiness over time?
And that's a way that I've approached my own chronic illness and with long COVID and I think it's probably a helpful framework for other people.
[00:19:38] Jill Brook: Oh, right. I'm guessing that founding a tech company is not the easiest thing for your stress level.
[00:19:44] Rohan: Maybe not, but I think anything we do in the world has stresses and that's just a natural part of it. Whether it's hanging out with your family, friends or going to work. So, you know, what's been nice about working on a tool that I think does help you regulate. As you know, in our team meetings, we started with biofeedback exercise. We all check in, we breathe, and only when we finish and our HRV is in a little higher state, do we hopefully in higher state do we start right?
And I think there's so many ways that trying to be mindful and kind to ourselves, understanding that our mind and our body are intimately connected and some things are in our control and some aren't can be really helpful to, yeah, make it a little bit less, maybe stressful than you might imagine. Even in the midst of busyness to be able to not be super sympathetic, I guess, all the time.
Mm-hmm.
[00:20:39] Jill Brook: So tell us a little bit about the specifics of your company and your technology. So maybe we could start with, why is your Lief device better than an Apple Watch? And then how does it work if somebody was kind of curious what your business is all about?
[00:20:58] Rohan: Yeah. I'm an inventor and tinkerer. I really just wanted a tool to help myself feel better, you know, and I actually started with the Apple Watch, that was our initial wouldn't it be easy if we could just make an app? And I had been a programmer in the past as well as, you know, scientist. And so that was our first go around.
And it just turns out that, you know, back to that story of the initial biofeedback experiments with fingertip temperature. If you are gonna do biofeedback, you're teaching your body, basically, you're giving it feedback on when to do certain things, which you're not even fully conscious of, to make the number go up or down, the direction you want it to go.
If the data's not accurate, you can't learn because you're feeding it, it's kind of like a garbage in, garbage out problem in, in machine learning where it's like, well, you know, no matter how good your algorithms are, but how smart your human brain is, and, and it is an incredibly smart thing, if you're not giving an accurate data, you're not gonna be able to learn. So that's, I think the first thing that we did is to create an ECG, which is like the clinical gold standard for measuring HRV, the shape of the device, the placement of the electrodes, where it goes on your body. I mean, it's like all of it is designed to be a super highly accurate HRV sensor, the most accurate you can imagine. And then on top of that, we built this haptic vibrational interface where coming back to my problem, which was like, well, I really wanna know when I need help and when I wanna self-regulate, but I don't want everyone else necessarily around me to know.
So I can't pull up my phone and ask the world to stop while I do an exercise on this weird machine? So how could I communicate to myself invisibly? Well, you could use vibration. And so that was the, the second insight that we made that you could actually mirror how your heart rate variability, how your heart rate is changing through a pattern of vibration against your skin and that the human body and brain could learn to interpret that over time and control it just as easily as if you were looking at an auditory or a visual signal, which is how bio feedback's been done for 50 years. So it's really those two things, I think, like, being really accurate and having more insight because of that accuracy and then being able to do something actively in the moment to actually shift.
[00:23:02] Jill Brook: And the patch it go, kind of goes on the chest, right. On the ribs.
[00:23:08] Rohan: Exactly right.
[00:23:09] Jill Brook: Okay. Okay. And then what other specifics would would you want people to know about if they were interested in this?
[00:23:16] Rohan: It would really, I think, depend on what someone's looking for and for someone who's struggling with POTS and I think we are still learning a lot about POTS, actually one of our patients who I got to know a little bit, she sent me a book about dysautonomia, and that was sort of the beginning of me learning about some of these conditions of the autonomic nervous system, which I wasn't an expert in and wasn't fully aware of.
So I think I have to preface this by saying I don't know the answer. I think the way that our customers are using a Lief now is one for tracking. It's like, oh, similar to the athletic example you mentioned. My HRV is really low today. I'm not gonna push myself and I'm gonna take a step back and go slow.
That's, I think, one big major use. The second one is, is breathing and, you know, breathing and biofeedback it seems like it shouldn't really make a big difference on our body and our mind, cuz it's just breathing and we're doing it anyway. I mean, hopefully, hopefully we're breathing. But it's just really remarkable from a neuroscientific perspective, from an autonomic nervous system perspective, from POTS, from mental health.
It's really fascinating how, if you are breathing in particular ways where you're using biofeedback to shift, you know, your HRV, like dramatically higher. I think that there are dramatic changes that can happen there. And, and that is probably why in the literature we see these massive effects now that, that are comparable in the mental health world at least to, you know, medications and CBT which are kind of like the gold standard and have been used for so long. So yeah, a little bit of a convoluted answer, but I think those are a couple of the different ways that you can use a tool like a Lief if you are struggling with POTS.
[00:24:58] Jill Brook: Well, and it's interesting that you brought up the breathing again cuz it reminded me that there's actually all kinds of new interest in the POTS world about breathing because there's some hypotheses that POTS patients are doing a form of mild hyperventilation a lot of the time, and I don't know if they think that it's a cause or an effect or both, or, you know, part of the whole bundle of issues.
But that is interesting that it's possible that a Lief could set you off as to when you're starting to kind of go down some of those roads.
[00:25:34] Rohan: Super fascinating. And again, you know, the causality is so interesting, right? It's like, is the POTS causing the shallow breathing? Is the shallow breathing in part exacerbating symptoms of of POTS and dysautonomia? I think it's a two-way street and we see this in mental health a lot, and I think there's been this false siloing of medical conditions into very narrow buckets of, okay, well here is this diagnosis and, well, this is a totally separate diagnosis over here that has nothing to do with that.
And there couldn't be any interplay between these two things. But I think what we're finding more and more with disorders that affect the autonomic nervous system, our breathing, our blood circulation, our heart, all of these very vital bodily functions influence our ability to get up and move around.
And also it seems like our ability to feel certain emotions and to have a range of, of flexible adaptations to the stressors in our life. And so, yeah, it's a new field of research and super fascinating. But I think what's interesting and available to everybody right now is, gosh, you can learn to do breathing techniques, even if you're not doing biofeedback per se, that help you shift how your autonomic nervous system is doing. And you can just kind of tell for yourself, is it helping me or is it not? And if it is, then maybe it's worth exploring a little more.
[00:26:55] Jill Brook: That's great. Yeah, I appreciate that you invented this for yourself and for everybody else who could use this same technology.
Where can people go to find you online if they wanna learn more?
[00:27:07] Rohan: Yeah, we're online at getlief.com, getlief.com. Shoot us a message anytime if you have any questions, we're happy to speak and, and talk it through and see if we can help.
[00:27:18] Jill Brook: Great. Thank you so much for your time and for sharing your story. And we, yeah, we appreciate all you're doing and wish your company all the best.
[00:27:28] Rohan: Such a pleasure. Thank you so much again.
[00:27:30] Jill Brook: Okay, listeners, that's all for now. We hope you enjoyed this episode. We'll be back with more next week. But in the meantime, thank you for listening. Remember, you're not alone, and please join us again soon.
