Sobering thought

Hi all,

Just had my PM check and plucked up courage to ask for a print out of the results. I was so supprised to see that in 2 1/2 years my little box of tricks has paced me 113.3 million times. Aren't these little guys just the best?

Love peace and happiness to all.

Baz

3 Comments

How amazing is that?

by donr - 2014-02-12 08:02:53

At 60 BPM, your heart does 2.6 MILLION beats per 30 day month, or in a 365 day yr, about 31.5 MILLION beats therefore in 2.5 yrs at the base rate alone it does about 79 million.

We look at the PM as amazing because of that number. To me the really amazing fact is that the human heart, a bunch of muscle, fascia, & other stray tissue contracts successfully that many times. To really boggle the mind, consider what mine has done in my 77 yrs -2,5 BILLION beats. Then there are the century people - roughly 3.2 BILLION beats.

And those numbers are for a BASE RATE! Doesn't consider that we actually run about 1.5 times that rate on the avg, so Ian, the runner has already in his 70 plus yrs come close to that 3.2 BILLION beats.

Long run, the typical human body is far more reliable than our PM. It's the short run where the PM equals or exceeds the body in reliability - that's about 10 yrs. For those of us whose electrical system failed, the PM beats us badly.

Yes, it's a credit to the electronics industry that it can produce something even remotely close to the human body in reliability for such a long time.

The real killers for electronics are heat & on-off cycling. Actually, it's not heat as such, but constantly changing temps. The PM at least functions in a very predictable temp environment - roughly 98 Deg Fahrenheit. Then there is the on-off business - our PM is turned on at its birth & stays on for as long as the battery will last. Electronics just love that kind of consistency. At least they tolerate it well.

For those of you who have only lived during the transistor & integrated circuit era, let me tell you how fortunate you are.

Back when I was a young sprout (Let's say 24 yrs old) in 1960, I was in Uncle Sam's Army in the air defense missile business, sitting atop Rattlesnake hill (Aptly named, BTW) with a system that had 1,200 electron tubes in it, (Valves, for the Brits among us). All those tubes operated at about 300 degrees F on the average. Certain parts of them glowed orange, making those parts at about 900 Deg F. Yes, we had a LOT of cooling Air conditioning. We averaged a daily failure rate of about 3 tubes per day, meaning our system reliability by today's standards really, truly, absolutely, totally SUCKED - BIG TIME.

So why did we use such a system? First, because it's ALL we had. Second, because we only really needed it to be reliable for about 30 min at a time. (That was about the length of time we might ever be engaged in a battle).

Our PM's , OTOH, have to be reliable 24/3650 to be serviceable for ten yrs. For a very crude estimate of reliability, using my old std of 30 min out of 24 hrs, a PM probably would last several hundred yrs - if the battery did not run out of energy.

We expect a lot from them & I'd say we get it.

I'd like to hear KAG's take on this subject - she was an EE much closer to electronics reliability then I was.

Don

Sobering thought

by Baz - 2014-02-13 01:02:13

Thank you for your replies.

The other amazing thing about my type of pacemaker is, how long the battery lasts.
I have a three leaded CRT. I'm paced 100% in both ventricules and 50% in the atria. I've had it for 2.5 years and the fuel gauge says another 4.5 years at this level of pacing........I love technology!!!

Thank again.

Baz

Interesting

by KAG - 2014-02-13 11:02:47

I didn't check Don's math, but I'm sure it's correct. I think Don covered it very well as usual. I (fortunately) didn't have to deal much with tubes. Only a bit in the AF as a avionics tech. Back in my young days the transistors and such weren't as reliable as the microcircuits are now. In the military systems I worked with as an engineer we dealt with 0.9998 or better reliability numbers for components. (1 = no failures) I thought those were pretty good but I'm told by a friend (engineer) that the medical reliability numbers are even better. I haven't checked them out... yet (I wasn't sure if he was just saying that to make me feel better when I first got my lil buddy). I agree with Don's estimate of a PM lasting almost forever if the battery didn't deplete. Even in the military systems the batteries were usually the weak point. Weak as in how long they'd last. Amazing how such a tiny battery can last 10 years.

Kathy

You know you're wired when...

You have a 25 year mortgage on your device.

Member Quotes

Just because you have a device doesn't mean you are damaged goods and can't do anything worthwhile and have to lie down and die. In fact, you're better and stronger. You're bionic!