Battery Status

Question:

by AgentX86 - 2018-06-30 00:14:04

"Has anyone experienced large battery status changes between interrogations and what was the protocol that was followed on those occasions?"

No, but thank you for warning me of this possibility.  It certainly heightens my awareness of this particular problem.  I'm pacemaker dependent too, and have no (known) escape rhythm.  Such things are about the only thing that scares me about the PM.

Battery Status

by dante - 2018-06-30 04:32:38

Thank you AgentX86.

I believe pacemakers manufacturers should check their records and see if my case was unique or if they need to review their protocol. My years of experience with scientific instrumentation in advanced chemical labs has thought me that you do not ignore outcomes that are more than twice the expected. Normally it means that something abnormal is going on and you ignore it at your peril.

Happy you are here!

by Theknotguy - 2018-06-30 10:45:55

First, let me say I am very happy to hear you survived and are doing well.  

I think you ran into the situation that proves doctors and technicians are human after all.  I did computer repair for 35 years and when I saw the battery numbers you relayed my first response was, "Aw shucks, bad battery!" (Or something like that. Mostly a lot more forceful.) 

Doctors and techs are trained to look at the medical side sometimes forgetting to look at the mechanical side.  If you were to graph your battery numbers you'd see a sudden cliff like drop off which would scream "Big Problem Here!"  But since doctors and techs aren't necessarily trained to look at the mechanical side they completely missed what happened.  When the tech set the date for another six months I would have been screaming in his/her ear that I wouldn't wait that long.  And, since you probably haven't had training on the electrical side, you didn't see a problem either.  After all, these people are supposed to know what's going on, right?  We shouldn't have to question their decisions, right?  It would be that way in a perfect world.  But we don't  live in a perfect world.  

If it's any consolation my doctor completely missed a problem with a heart drug.  I'm on Flecanide.  I like to do back woods trail hiking and take the dogs with me.  The first indication something was wrong was when I was walking along without any cares or problems and I hit the ground like a stone.  I'm out for about 30 seconds.  I call the doctor and say, "Hey I passed out for no good reason."  The second time I'm out with the dogs, get a funny feeling, then wake up with the dogs licking my face.  Call the doctor and say, "Hey!  It happened again!"  He does a check, orders a TEE, does the test.  Tells me I've got mitral valve regurgitation.  We'll treat it this way.  Yadda, yadda, yadda.  I'm out with the dogs again, not a problem in the world.  I turn the corner to go on the exit trail, everything starts to go black, I wake up six days later in intensive care with a newly implanted pacemaker.  Three years later I find out some people are allergic to Flecanide and it's been known to cause sudden death.  My doctor is very chagrined when I meet with him.  He's young and completely missed the sudden fainting with Flecanide to be a problem.  Needless to say I'm not on Flecanide any more.  My wife's been on it for years, no problem and it helps her.  

I didn't get an apology from my doctor.  You probably won't get one either.  An apology means a mistake and in the good ol' US of A that means a very expensive lawsuit and the doctor's insurance rates go astronomical.  So they don't dare admit an error.  My doctor handed me off to an older doctor in the group.  I'm not angry with the younger doctor because there were mitigating circumstances that would have made it almost impossible for him to pinpoint what happened.  And part of that would mean I would somehow have to know what was going on too.  It's marked on all my medical records that I'm allergic to Flecanide and if I go into sudden fainting again, I'll make a lot of noise and make sure someone looks to see what's going on.  

Has this happened before?  Probably has.  Did anyone catch it?  Good question.  Maybe they did, probably didn't.  Will we ever know, probably not.  It just makes you and me probably two of the luckiest people in the world.  Unfortunately the luck hasn't paid off for me on winning the lottery side, but I'm alive enough to complain and that's all that matters.  I'm sure from now on you'll be looking at the battery numbers when you get a pacemaker reading.  

The other thing I'm going to do is to get hold of my pacemaker techs.  Let them know about the battery drop off numbers.  I've got a great woman tech and I'll bet she doesn't know to look at the battery numbers.  Not that she isn't good, she probably hasn't had training on the mechanical/electrical side.  While this information didn't help you, maybe it can save someone else?  I'd also let your pacemaker manufacturer know what happened.  Maybe they can write a "check status" flag into their software program.  Like I said, it didn't help you but maybe it can help someone else.  

Oh, and in answer to your question, a civil engineer type of person, or a person who's worked on the electrical side, may have seen the battery numbers and would have noticed a problem.  Most other people wouldn't.  Like I said, after 35 years of working on broken computers, I'd have said, "Big problem here."  But that's after having seen it happen in the field.  

Once again, I'm very happy to see you made it through.  I hope you are able to have a long life with a minimum of events similar to what you had.  

Battery Status

by dante - 2018-06-30 22:08:20

Thank you Theknotguy & Robin 1.

In reply to TheKnotguy, YES, I did question the Technician when he told me that there was 1 year left in the battery, he then re-checked and the new value of 1y &4months was the result. I questioned him and the attending doctor and nurse again and I was told not to worry because even if it shows ZERO, batteries have 6 months margin before they expire. When I saw my cardiologist again I asked the question, and again I was reassured. 

I understand that, as Robin pointed out, these measuraments aren't accurate, but they MUST be more than a guess. In fact there is a fairly convoluted algorithim involved to predict remaining life. Whilist the final expected life isn't one that you could set a date on, nevertheless they must be accurate enough to predict when to do next check and when to replace the battery/device otherwise the interrogation would be useless.

I've had >40 years experience with complex scientific instrumentation and that is why I questioned the results but in the end I had to trust the professionals.   

My primary aim for posting here is to see if anyone else had a similar experience because, if that was so, then there would be reasons to insist that pacemaker interrogation programms have built in an algorithim to check if the status found during an interrogation fall within the expected range, ie within the error range that such measurements have (ie based on Measurement Uncertainties (https://sisu.ut.ee/measurement/introduction-concept-measurement-uncertainty) and if they are outside that range then to recommend the IMMEDIATE replacement of the battery or change the device.

Manufacturers may not like that but it would save lives. 

gas in the tank

by dwelch - 2018-07-01 20:00:57

its like predicting how long a tank of gas will go.  There are too many variables that are in constant change, how heavy the driver is on the gas and brake, the wind at any particular moment, hills, curves, air temp, humidity, etc.  Too many variables.

You might be a skiier in the winter and a couch potato in the summer, your winter usage more than your summer.  I might be the opposite, the algorithm cant predict that or cover all the possibilities.

I have had pacers for 30 years, they have a pattern they tend to follow, implant, an extra visit or two the first year, if all looks well and dialed in then annually for years, as the battery voltage dips to a certain level they start bringing you in more often, every 6 months.

Now technology has changed over time as well, my first one or two, no phone boxes, then came a long period where I had a box at home that you put the handset of your phone on it, it modulated your ekg just like a modem does (if you dont know these terms then dont worry about it).  You put the magnet on then off.  The magnet rate turns your heart rate into a voltmeter or vice versa your BPM reflects the voltage on the battery and from that without you coming in they can check the battery between office visits.  It depends heavily on the health plan and practice as to how many of these you get and as with one doc as I got within the last few years based on the rough estimate the phone checks increased in frequency.

Two things, now they have these sit by your bed boxes that can check on you as much as every day, if not whatever schedule you have setup with your doc (again heavily depends on health plan and practice none of these things come for free, someone is getting paid nicely to collect and process this data no matter how trivial the job).  So if you have one of those and it is operating fine then you have yet another potential malpractice suit, it should have alterted them immediately.

The second thing on the negative side is my doc is telling me that insurance is starting to insist that the pacers are taken to safety mode.  If the device says it has 2 months go to, and you have a big family reunion planned in some faraway place, they used to be able to move your replacement up.  You can see when they multiply it out, saving a few weeks or months for every device replaced adds up, at least enough to cover the bonus for that year for the person who thought of it.

At the end of the day just like humans and cars and phones and even pencils.  These devices are not perfect, their high cost is not due to complexity, it is due to paperwork and testing and analysis of the design to make them more reliable than your cell phone or tv remote control.  There is still an expected failure rate in the field. They expect one out of some number of units to fail over a large sample, out of 1000?  10000? 1000000?  I dont know, but there is a number.

It sounds like either, someone wasnt watching, it got damaged somehow, or it just drained to quick at the end.  There might be someone at fault, might not it could have just been the one in ten thousand.

You can play a role in a couple of ways, not that this is your fault unless there was damage caused by you which I doubt happened here otherwise you would have said something.  Ask for a copy or your copy of the printout/report as they are printing the doctors copy.  Your body, your data, not theirs.  This will show the poorly estimated battery life, also remember there are lawyers behind this as well, brand new device, told I am supposed to get 10 years out of this model and brand, morning after implant says 7.5 years.  The lawyers are not going to let this overestimate, under is okay.  So assume it is wrong for that reason as well. 

As time passes it will have a shorter period, do not get worried.  But as you get into those last couple three years and the time starts dropping off, this is the other thing you do for yourself.  Be aware of your rate and how you feel.  I you climb some stairs and are unusually out of breath or wiped out check your pulse (full minute, no shortcuts always a full minute)  if it is not elevated due to the activity, if it is 65 no matter what you are doing resting or hiking.  Call the doc, it may be time.  I have not heard the 6 month window thing I have heard 3 month window, and in reality I bet nobody is going to give you an answer in this lawsuit friendly world as to the actual time. 

This is the next phase in the pacer life, I am on number five.  implant, recovery, normal life, battery decline, replacement.  repeat.   That decline might take 3 years maybe more maybe less.

I dont think they are going to add firmware to watch the battery rate of decline, I think this is going the other way as they are going to rely more or too much on those by the bed checks you every day/night boxes.  Another task on yourself, if you have one, check it periodically to see that it is plugged in and working.

And to be brutally honest, I suspect most patients dont outlive their first device, thus the typical life expectancy of the devices.  Every single line of code in that firmware costs a lot of money, they are not going to add extra code, extra cost, extra risk, until it is warranted.  We have far bigger problems with the over the air access to the devices being totally unprotected, talk about risk to lives, they have to solve that one first, and  honestly there isnt a technical solution that will work, other than turn off the long range radio (no more home by the bed boxes), do not put it in the device, save cost and battery.  Go back to only supporting the short range radio, where you have to be sitting there next to their box with the radio right on top of the device.