- Introduction
- Current Problem
- What is Heart Rate Variability?
- Low HRV and Anxiety Disorders
- Low HRV and Substance Abuse Disorders
- How do we track HRV?
- Breathing exercises to increase HRV
- Zenbeat’s solution
- Conclusion
Growing up, I was never shy. I had an extremely bombastic and energetic personality. Most people knew me as the type of kid to go up on stage in front of everyone and give the best wedding speech of all time through improvisation and pure courage at 8 years old (this happened and I was even featured in the wedding video).
My courage and tenacity came from a huge need for attention. I was an attention seeker and got my daily attention dose from being a cute little showman from the time I was very young.
My anxiety-free living as a kid started to change when I was about 12 or 13. Going into middle school, my courage was replaced by fear and my energetic personality turned into anger against everybody. My attention-seeking outlet used to be with my parents and close family friends but was now replaced with attention-seeking through social media.
My anxiety spiked at 12–14 when I started to get addicted to YouTube, video games and social media. I would stay up all night scrolling meaninglessly through Instagram and posting cringe-worthy stories on my account. This all was accelerated by the COVID-19 pandemic which forced me to stay at home and increased my loneliness and anxiety.
When I finally got out of my dark hole of loneliness, bad habits and anxiety it was through friends, family and mentors who inspired me to be better. Still, even now, all these years later, I go back to those bad habits as an escape from anything that makes me anxious in the real world, escaping to YouTube, social media and video games.
A while back I asked myself, is there any way I could create something that helps me manage my anxiety while also letting me avoid bad habits that make that anxiety worse?
As I started to learn about anxiety, I realized that it was a bigger problem than I thought. Not only is it linked to bad habits but it also contributes to mental health disorders and even addiction relapses.
I was inspired to see if I could build something so I started with a proof of concept and began sharing my idea to help people cope with substance abuse.
As I marketed the solution to experts in the field, I experienced immediate skepticism about the solution because there are still very few studies on the link between an HRV monitoring solution and averting relapses.
I did, on the other hand, receive a lot of interest from people struggling with stress and anxiety disorders. I also found that anxiety and other disorders are linked in many ways, for example:
- 10 to 40 percent of people with alcohol addiction are also affected by a panic-related anxiety disorder.
- 10 to 20 percent of people with an anxiety disorder abuse alcohol or other drugs.
- Most alcoholics also report that their anxiety problems came before their alcohol abuse.
Globally anxiety disorders are the most prevalent mental health disorder, with over 284 million people affected each year. That means that 4% of the world's population has anxiety and this percentage gets worse in the U.S.
In the United States, anxiety disorders affect over 40 million adults, which is about 19.1% of the population. Among U.S. adolescents aged 13–18, the prevalence of any anxiety disorder is estimated to be 31.9%, with untreated teenagers at higher risk for various challenges.
Lived experience and statistics show that this is a massive problem. Now how do we solve it? Pst… hint *Heart Rate Variability* hint.
Heart rate variability is the measurement of the variation in time between each heartbeat. To be more specific, it’s a measure of how good your nervous system is at adapting: its ability to switch between the parasympathetic and the sympathetic states.
Your heart rate variability is determined by your autonomic nervous system which handles 90% of your body functioning. Our autonomic nervous system constantly reacts to the information our brain processes throughout the day, whether that’s a stressful death in your family or good news about a job promotion.
Our autonomic nervous system is divided into the parasympathetic system (rest and digest) and the sympathetic system (fight or flight). The parasympathetic system is a network of nerves that relax your body after periods of stress or danger. The sympathetic nervous system activates and responds to dangerous or stressful situations.
Persistent negativity in your life such as poor sleep, stress, unhealthy diet, social isolation, and inactivity can disrupt the autonomic nervous system, causing an overactivation of the sympathetic (fight or flight) response.
A high HRV is essentially a numerical measure of how good you are at switching between the sympathetic and the parasympathetic state.
Higher HRV indicates more optimal autonomic nervous system function and can help reduce high blood pressure, depression, and anxiety.
With a low heart rate variability state, the autonomic nervous system is less able to switch from the sympathetic to the parasympathetic nervous system. This can sometimes lead to or is caused by an overactive sympathetic nervous system which is associated with anxiety disorders.
As long as there is a perceived threat, the body’s stress response remains active, releasing cortisol to keep the body amped up, resulting in feelings of being on edge, worried or anxious.
Controlled studies show that high HRV results in improvements in:
- Anxiety
- Depression
- Asthma
- Fibromyalgia
- Chronic pain
- Sleep problems
People with high HRV are better at regulating their emotions. They’re better at controlling their impulses and they’re better at processing information. If your heart rate variability is constantly low, it means that your body is probably stuck in alert mode or stress mode.
Biofeedback exercises, which sync respiratory and heart rate patterns, can increase heart rate variability. This eventually can lead to the person becoming more coherent and more resilient to stimuli.
To better understand why HRV impacts anxiety, we must understand the vagus nerve. The vagus nerve mobilizes bodily responses by scanning for safety or danger in a situation.
The vagus nerve is why our breathing slows and our body relaxes when we are comfortable. It’s also why our heart rate jumps and our stomach turns when we sense danger. It plays a central role in alerting the autonomic nervous system on whether it should be in a state of calm or alarm.
For the past few decades, the research has highlighted the link between low heart rate variability and mental health. A meta-analysis of 36 studies found anxiety disorders (e.g. PTSD, generalized anxiety disorder, panic disorder, social anxiety disorder) are associated with significant reductions in heart rate variability.
The reason for this is that anxiety in all its forms ultimately creates a reduced ability to rest. Over time this negatively affects people’s cognitive, behavioural and psychological responses.
A reduced capacity to regulate negative stimuli leads to reduced vagal flow, lowering HRV and increasing feelings of anxiety.
“The significant reductions in heart rate variability found in the meta-analysis echoed previous theoretical models, indicating that the prefrontal cortex’s ability to regulate processes that contribute to the experience of anxiety are mediated by the vagus nerve, which is reflected in heart rate variability.” Source
Heart rate variability (HRV) is an indicator of autonomic abnormalities. Little is known about the role of HRV related to substance use disorder. However, some studies show that higher HRV can help addicts through their cravings.
A total of 14 studies were reviewed. Studies included outpatients with a prescription or nonprescription opioid misuse behavior with a primary diagnosis being chronic pain or substance use disorder (SUD). Significantly decreased resting HRV was found in substance users compared to healthy controls. Lower resting HRV has been significantly associated with stress, craving, and greater symptom severities in individuals with SUD and other substance dependence. HRV indices can be potential measures of homeostatic imbalance and self-regulation flexibility.
HRV may be a useful tool for monitoring early indication of relapse so that relapse prevention measures can be implemented in a timely manner. Future studies in substance use may benefit from examining HRV in relations to substance use and relapse signs and symptoms in a larger population to guide future relapse prevention strategies.
Based on some new studies, increasing HRV through biofeedback may be an accessible, cost-effective intervention solution.
ECG (electrocardiogram) and PPG (photoplethysmography) are the most common ways of recording HRV data.
ECG measures the electrical activity of the heart over a period of time through electrodes that are attached to the skin. ECG essentially records the electrical activity of the heart muscle.
PPG is a very simple optical technique for measuring HRV. Unlike ECG, which uses electrodes, PPG applies light reflection to detect the blood volume changes in peripheral arteries which occur with each heartbeat. Recordings are usually measured on parts of the body where blood vessels are close to the skin, like fingertips or earlobes.
The advantage of the ECG method is that it has been proven to be more accurate and comprehensive than those obtained through PPG. This is mainly because ECG reads the electrical signals produced by the heart activity directly, while PPG provides a more indirect measurement, using light reflection to detect the pulsating activity of the heart.
PPG measurements are influenced by the proximity of the blood vessels present in the particular spot you placed it, this makes the accuracy of PPG change according to the body position. The accuracy also can vary depending on other factors, for example, the effect of ambient lighting or even motion factors.
ECG, on the other hand, even though it presents many advantages it also has problems such as it relies on a physician to collect and interpret the data. This greatly limits access to this tool for diagnosis, care, prevention, or general HRV tracking.
For my project, PPG seemed like the most accessible and easiest way to collect data so I decided to move forward with this technology.
What’s a good HRV?
Heart rate variability is very personal. What’s considered a good HRV will vary from person to person. Multiple formulas are used to calculate this metric. Two of the most common are the root mean square of successive differences between normal heartbeats (RMSSD) and the standard deviation of normal intervals.
Wearable devices use these formulas to compute HRV, and current data shows that the desirable range may be as broad as 20 to 150 milliseconds, depending on the individual.
Resonance breathing has consistently been shown to increase HRV, mood, and adaptability. Resonance breathing is a technique that involves deepening and slowing down your breathing to a specific pace, typically around 6 breaths per minute.
This breathing technique synchronizes your parasympathetic nervous system, promoting calmness and improving the balance in the nervous system.
Studies have shown that regular resonance breathing can significantly improve HRV parameters such as SDNN, pNN50, and total power.
I named my solution: Zenbeat! Zen refers to a perpetual state of calmness and Beat refers to our heartbeat.
V1 of Zenbeat
My first iteration of Zenbeat was to help substance abuse disorder patients manage their cravings. The idea behind this was that heart rate variability which was correlated to stress, was potentially able to detect cravings. This made sense because HRV biofeedback has been proven to help addiction patients lower their cravings, especially opioid cravings.
However, over long research hours, I realized that there were not enough studies yet to say that HRV could be directly correlated to craving. Most studies alluded to it being either indirect or addiction-producing low HRV.
I used Oura ring to create a prototype version to prove that it could be possible in time to make something like this.
V2 of Zenbeat
As I continued down this path of addiction recovery research, I started building a prototype of a full-stack application that could detect and prevent cravings in real-time. This prototype application taught me a lot about what features I wanted to integrate into the app.
This included a resonance breathing exercise feature, a calendar, graphs of your progress and other interesting ideas that came to mind… It also taught me a lot about full-stack development, react, javascript and other coding stuff.
But I ran into one pretty big roadblock, most of the wearable technology on the market did not provide real-time HRV data which would be necessary if we wanted to intervene in real time.
I realized I probably needed to build my own sensor so I applied for a grant from an amazing team at 1517 who generously awarded me enough funds to buy my own sensor.
V3 of Zenbeat
V3 of Zenbeat aims to utilize real-time HRV data from the PPG sensor built into the small Emotibit. This sensor can easily be placed on you’re finger or arm and immediately starts streaming data to the app.
The idea for the app in the future is that every time your heart rate variability lowers based on the readings from the PPG sensor, it will automatically notify you and it will help you calm yourself down using resonance breathing techniques.
There are already apps on the Apple watch that do what Zenbeat aims to do like the Breathe app and other stress trackers. These stress tracker solutions work very well and beat Zenbeats in terms of convenience for the user (using Apple infrastructure). This is why V4 creates a new application for PPG sensors and evolves Zenbeats further.
V4 of Zenbeat
The objective of V4 is to use a PPG sensor (already used in sensor infrastructure such as Apple Watch and Oura ring) that accurately monitors and displays the breathing cycle and rate in real time. By providing immediate feedback on breathing cycles wearable devices enable individuals to engage in mindful breathing exercises and help to reduce stress.
In conclusion, the monitoring of patients both in hospital settings and at home, has significantly benefited from the advancements in wearable devices. These devices provide the ability to continuously and non-invasively track various physiological parameters, enabling timely interventions and improving patient care.
Zenbeat aims to help use novel ways of detecting and preventing stress using a PPG sensor to track HRV. The stretch goal with Zenbeat is to eventually be able to use AI to analyze PPG data to track breathing rates and cycles in real-time.
This is the first article in a series of Zenbeat articles that take you through the process of solving anxiety and stress for millions of people across the world.