jrannis
Senior Member
- Location
- Fort Lauderdale/ Miami
I sure the narrator missed a decimal point when he was reading the script. Could be more like .04 or .40 or something like that
WOW Defib
- Thread starter mikeames
- Start date
- Status
Or 40mA maybe?
zog
Senior Member
- Location
- Charlotte, NC
I think that is likely right
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
The voltage and current numbers on Modern Marvels do not appear far off the mark.
Take a look at this link from one of the AED manufacturers. Down toward the middle they have some graphs of current versus time and average current delivered. The Zoll system (being promoted by this link) delivers an average current of 20A into a 75 ohm resistance for the during the positive half of the pulse. That really is 30kW and 1500V, but only for about 6mS.
http://www.zoll.com/product_resource.aspx?id=728
-Jon
Take a look at this link from one of the AED manufacturers. Down toward the middle they have some graphs of current versus time and average current delivered. The Zoll system (being promoted by this link) delivers an average current of 20A into a 75 ohm resistance for the during the positive half of the pulse. That really is 30kW and 1500V, but only for about 6mS.
http://www.zoll.com/product_resource.aspx?id=728
-Jon
boboelectric
Senior Member
- Location
- Eighty Four,Pa.15330
That's a lots of watts!
dbuckley
Senior Member
- Location
- Canterbury, New Zealand
As we all know, its the current that kills, and funnily enough its the current that fixes a heart in fibrillation. Since defibs are usually used externally to the victim the voltage has to be high enough to get a big current through the heart. A charged capacitor is connected to the paddles using a vacuum relay.
The old monophasic defibs used higher voltages than the modern biphasics, and the replacement of old defibs with biphasics has caused many old defibs tocome onto the surplus marketplace, and these are an interesting source of high voltage components...
http://www.youtube.com/watch?v=BqgxQG1PyfM
The old monophasic defibs used higher voltages than the modern biphasics, and the replacement of old defibs with biphasics has caused many old defibs tocome onto the surplus marketplace, and these are an interesting source of high voltage components...
http://www.youtube.com/watch?v=BqgxQG1PyfM
rkrieger
Member
Unfortunately, I have been the recipient of over 10 "cardio-versions" to correct atrial fibrillation. I am no way an expert except to say that each time I get converted, I know for a fact that the machine is set at 200 joules. (cause that is what my history says will work the first time). Until they established that number, they would start out a 100, then 150, then 200. Each time, of course, you get another "zap" on both your front and back side where the electrodes are. They have different brands of electrodes and the procedure is highly variable by the techniques of those performing it. Some times, I have had very painful blisters, burns, while others, just some redness and itching.
I don't want to go back again soon, but I will ask my cardiologist about the specifics of the defibrillator he uses in the ER.
For those who are wondering, they tie down your arms and legs and knock you out usually with Brevitol or Versaid. You wake up and hopefully are in sinus rhythm and of course, you have the "marks". Beats being on Coumadin though!!!!
I don't want to go back again soon, but I will ask my cardiologist about the specifics of the defibrillator he uses in the ER.
For those who are wondering, they tie down your arms and legs and knock you out usually with Brevitol or Versaid. You wake up and hopefully are in sinus rhythm and of course, you have the "marks". Beats being on Coumadin though!!!!
Sorry to hear that you need such serious medical procedures on a regular basis.Unfortunately, I have been the recipient of over 10 "cardio-versions" to correct atrial fibrillation. I am no way an expert except to say that each time I get converted, I know for a fact that the machine is set at 200 joules. (cause that is what my history says will work the first time). Until they established that number, they would start out a 100, then 150, then 200. Each time, of course, you get another "zap" on both your front and back side where the electrodes are. They have different brands of electrodes and the procedure is highly variable by the techniques of those performing it. Some times, I have had very painful blisters, burns, while others, just some redness and itching.
I don't want to go back again soon, but I will ask my cardiologist about the specifics of the defibrillator he uses in the ER.
For those who are wondering, they tie down your arms and legs and knock you out usually with Brevitol or Versaid. You wake up and hopefully are in sinus rhythm and of course, you have the "marks". Beats being on Coumadin though!!!!
I had heard that the side-effects of Warfarin can be fairly unpleasant.
You have my best wishes.
rkrieger
Member
Matter of degree.........
Matter of degree.........
Thanks for your thoughts......... Up until I was about 55, I didn't have a health concern to worry about. Then after having an irregular heartbeat and after tons of time and visits to the Cleveland Clinic, they found a heriditary condition called IHSS. (Idiopathic Hypertrophic Subaortic Stenosis). My Dad had the same thing but could not be "converted" back to sinus, so he was on Warfarin for years and years. The septum (between the two chambers of your heart) is thicker than normal in my case and often interferes with the electrical signals of the heart. Periods of high stress or exertion can trigger an atrial fib episode. Luckily, I have always had success at cardioversion so far. Probably, more information here than you need or want, but I was feeling "wordy" today!!! This is the same condition that has caused sudden death in healthy athletes who did not know they had this condition.
Thanks again for the concern............. I have come to realize the importance of health and also know that most folks take it for granted. As we get older (63 !!), it is no longer an assumption.
RKrieger
Matter of degree.........
Thanks for your thoughts......... Up until I was about 55, I didn't have a health concern to worry about. Then after having an irregular heartbeat and after tons of time and visits to the Cleveland Clinic, they found a heriditary condition called IHSS. (Idiopathic Hypertrophic Subaortic Stenosis). My Dad had the same thing but could not be "converted" back to sinus, so he was on Warfarin for years and years. The septum (between the two chambers of your heart) is thicker than normal in my case and often interferes with the electrical signals of the heart. Periods of high stress or exertion can trigger an atrial fib episode. Luckily, I have always had success at cardioversion so far. Probably, more information here than you need or want, but I was feeling "wordy" today!!! This is the same condition that has caused sudden death in healthy athletes who did not know they had this condition.
Thanks again for the concern............. I have come to realize the importance of health and also know that most folks take it for granted. As we get older (63 !!), it is no longer an assumption.
RKrieger
Weaver Road
Member
- Location
- Willington, CT
Joules!
Joules!
I come into the world of code AHJ from the Fire Service (25 years) I was there before the defibs made it out of the hospitals to the field, and all I have read here goes along with my years of training. Our protocols are 200, 200, 360 joules, then 3 more at 360 if conversion hasn't happened. I don't know the exact techicalities as well as some of you guys with electrical engineering knowledge, but I can tell you for sure that you can snap someone right off the other end of a long metal grandstand bench if they don't get off it before you zap the poor sucker laying down on it. You also can't shock if there is nitro present (like from a patch) or BIG flames! There are a bunch of other safety protocols that tell me it's something I would rather be giving then given!:roll:
Joules!
I come into the world of code AHJ from the Fire Service (25 years) I was there before the defibs made it out of the hospitals to the field, and all I have read here goes along with my years of training. Our protocols are 200, 200, 360 joules, then 3 more at 360 if conversion hasn't happened. I don't know the exact techicalities as well as some of you guys with electrical engineering knowledge, but I can tell you for sure that you can snap someone right off the other end of a long metal grandstand bench if they don't get off it before you zap the poor sucker laying down on it. You also can't shock if there is nitro present (like from a patch) or BIG flames! There are a bunch of other safety protocols that tell me it's something I would rather be giving then given!:roll:
Last year my cousin had an operation to repair a hole in his heart.Thanks for your thoughts......... Up until I was about 55, I didn't have a health concern to worry about. Then after having an irregular heartbeat and after tons of time and visits to the Cleveland Clinic, they found a heriditary condition called IHSS. (Idiopathic Hypertrophic Subaortic Stenosis). My Dad had the same thing but could not be "converted" back to sinus, so he was on Warfarin for years and years. The septum (between the two chambers of your heart) is thicker than normal in my case and often interferes with the electrical signals of the heart. Periods of high stress or exertion can trigger an atrial fib episode. Luckily, I have always had success at cardioversion so far. Probably, more information here than you need or want, but I was feeling "wordy" today!!! This is the same condition that has caused sudden death in healthy athletes who did not know they had this condition.
Thanks again for the concern............. I have come to realize the importance of health and also know that most folks take it for granted. As we get older (63 !!), it is no longer an assumption.
RKrieger
He is in his late forties and evidently had this defect from birth although it was only just recently discovered.
What triggered the visit to his doctor was that he thought that he was having to breath harder to get oxygen into his blood.
That is, harder than it had been in his previous marathons.
Fit guy otherwise. He has completed the London marathon on a few occasions, the New York at least once, the Great North Run often and quite a few other charity events.
Yes, you're right. You can't take good health as an assumption.
To everyone else here and, in particular, the mods, yes I know it is off-topic.
But we are all human.
It looks to me like they deliver the 200 J (and probably most of the 20 amps) into an internal impedence network.
From that website:
"The characteristic “sawtooth” shape shows how the resistor network in the defibrillator continually changes"
So there is no telling what amount of energy or current is actually delivered to the patient.
Although the very short duration may make some difference, I have always believed that 1 amp = "Kentucky fried".
Steve
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