|Jack Ganssle's Blog
This is Jack's outlet for thoughts about designing and programming embedded systems. It's a complement to my bi-weekly newsletter The Embedded Muse. Contact me at email@example.com. I'm an old-timer engineer who still finds the field endlessly fascinating (bio).
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Is a Heart Rate of 72,123 Beats Per Minute Possible?
August 19, 2020
In Embedded Muse 404 I ran a "Failure of the Week" from S. Stewart:. When the Wyze watch Android app doesn't sync on Blue Tooth it seems to fill some data fields with 72123:
Reader Jagmeet Singh Hanspal was intrigued and sent me his careful and fun analysis of this 72,123 BPM heart rate. The following is from his email:
Looking at the and 72123 error value, got me curious enough. I wanted to verify what was going in my mind looking at that number 72123 bpm heart-rate (or pulse). And, I remembered there was a correlation between pulse and body mass that I had seen someone had graphed it out across various sized mammals etc. So, a quick google search provided:
Well, it also showed the trend/equation which was quite useful.
But I wanted some tabulated data and that too was not hard to get from a further quick search.
I finally wanted to rest my mind regarding what I was thinking, that, if some "imaginary" organism were to have a heart rate of 72123 bpm, how small would it have to be to support its metabolism, and does it match with the one I'm thinking of?
So, with Mass (kg) = (240/Pulse)^4 ------ Modified equation from the graph above
We can calculate, that for 72123 bpm (according to the equation at-least) the imaginary organism should be 1.22 x 10^-10 Kg or about 0.122 micrograms.
This is the weight of pollen grains.
But, there has to be an error. Maybe the equation is not fully correct. As the trend has been calculated only over a range from Rat to an Elephant (or 25 gm to 3000 Kg), which although a big range even if there were a small error, it would manifest itself much more when we go to micrograms or other order of magnitude lower/higher. So, calculating the pulse data in the table again with this equation, we note some differences in calculated values vs the given:
I am hard-pressed that these look ok over this range, but if the equation were actually:
Mass (kg) = (240/Pulse)^7
And calculating the pulse values in the table again it is shifted a bit but still accurate to that order of magnitude:
Using the new equation we will see that the weight of such an organism comes to be around 4.5 x 10^-18 Kg or femtogram range, which is the weight of known viruses. I am sure the pulse rate 72123 bpm is not at all wrong but is the heart rate of the coronavirus getting displayed by the equipment!
But I am wrong, this organism does not have a heart looking at all the world crisis it has caused. Or does it? Maybe it is showing some new ways through a hard lesson? Only if we get our act together in this pandemic.
Thanks Jagmeet! What fun it is to play with ideas and numbers!
Feel free to email me with comments.
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