Last evening we had a fun-filled family outing at the NTR gardens, Hyderabad with parents, us and the kids together. Among all the attractions we simply loved the thrill of the water slide on the Machan Tree House.
Even through the water slide lasts for only for about 15-20 seconds, the thrill of being in complete darkness, with the boat in full speed rushing down almost like in state of free-fall and it's unexpected twists & turns till one reaches the bottom really drives up the adrenaline. The screams tell it all!
Monitra's upBeat® Biosensors
It just so happens we at Monitra Health are doing extensive testing of our upcoming product, upBeat®, wearable medical grade biosensing skin patch that continuously 24x7 captures electrocardiogram (ECG) and tracks posture as well as activities.
My kids are always excited about wearing upBeat® as these band-aid like patches makes them feel like the Iron Man with his Arc Reactor core in the chest. Weekends are the only days when we can be around to monitor the biosensors when kids wear them. This time, it was the turn of our five-year old kid who had worn the biosensor yesterday.
After yesterday's outing, we were keen to observe what happened to heart rate specifically during the adrenaline packed water slide.
The Baseline
The electrocardiogram (ECG) about 3 minutes before getting onto the water slide is given below. It had a pretty stable baseline with the heart rate of about 110 bpm at this stage.
The Water Slide - Pre, During and Post.
The heart rate (HR) before, during and after the water slide is plotted below. The moving average HR is about 115 bpm before the ride starts, immediately rising to an average of about 145 bpm after the water slide starts and drastically falling to about 100 bpm towards the end of the slide. Please do note that the HR rises thereafter to about 130 bpm (higher than before the slide started) which could be attributed to something called the lingering effect.
See reference 2. Researchers at the University Hospital in Mannheim, Germany, monitored the heart rates of 55 young people (average age, 28) before, during, and after they rode Expedition GeForce, a roller coaster in Hassloch, Germany. The ride also had a lingering effect: About half of the riders had irregular heartbeats for several minutes after they got off, even after their heart rates returned to normal.
The Physiological Response to Thrill Rides
Background
It is well researched and known that the heart rates usually increase during the amusement rides. See references at the end of the article. It is therefore recommended that the persons with high blood pressure, a previous heart attack, an implanted pacemaker or defibrillator, and others with proven heart disease, should not ride a roller coasters.
Sympathetic Nervous System - Fight or Flight Response
The body's reaction to fear, stress, excitement and anxiety is a result of the instinctive fight-or-flight response. Our bodies involuntarily react to dangerous situations through the sympathetic nervous system. Several responses in various parts of the body prepare us to deal with possibly life-threatening, or sometimes just scary, situations.
The autonomic nervous system consists of two opposing sub-systems - (1) sympathetic nervous system and (2) parasympathetic nervous system. The parasympathetic nervous system relaxes the body while the sympathetic nervous system prepares the body for fight or flight. This response is hard-wired in humans to protect us against threats from predators and other aggressors. Your body prepares itself to fight or flee in the face of perceived danger.
For many people, the faster heart rate during a roller coaster ride is well within that limit. As the researchers pointed out (Reference 2), younger people without heart disease needn't worry about a heart-pounding ride turning into heart-stopping one.
Some Thoughts
This article highlights body's response to one scenario. There is a lot of physiological information that one can mine from the human body to derive clinical insights. While continuous 24x7 extended monitoring generates phenomenal amount of data, this big data can be used for generating actionable clinical insights for chronically ill people and others too.
When we can monitor every minute detail of jet engines today, we should also be monitoring human beings in their normal surroundings not just in intensive care units in hospitals. See reference 4.
References
Tarassenko L, Topol EJ. Monitoring Jet Engines and the Health of People. JAMA. Published online November 15, 2018. doi:10.1001/jama.2018.16558