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View Full Version : Hpw many fatalaties from using TENS Units?


Bippy the Beardless
12-17-2004, 10:48 AM
TENS (Transcutaneous Electrical Nerve Stimulators) are commonly used for pain releif. It is also believed that they can be dangerous if the electric charge ends up going through the heart. I have done a web search but cannot find any data on how many fatalities occur per year using such equipment. When I have used one on my back I know that the pads occasionally fall off, and it is easy to forget to switch off the unit before you attempt to pick up the pad. So I have shocked myself from my left hand to right central back which is a path that may include the heart. I susspect other users have made similar mistakes. So what are the fatallity statistics, and how dangerous are these things really?

bouv
12-17-2004, 11:09 AM
I work as a biomed tech in a hospital, and encounter these devies. They are safe, if not, then they wouldn't let people use them. By that I mean they let untrained people take them home with them, even though they may, in theory, change the settings, have the pads placed improperly, etc...If there were significant risk to your heath, then they would only be used by trained professionals at the hospital/PT location, like a standard defibrillator. It has lots of current, and can kill, and so is only used by those who know what they are doing.

Here is an FDA article. (http://www.fda.gov/cdrh/d861.html)

It's not on TENS units themselve, but about 1/3 of the way down, it lists devices classified as nonsignificant risk devices. These are deivices that, no suprise, have no significant risk to human health when used.

Zsofia
12-17-2004, 11:13 AM
I dunno, I just dropped in to mention that they're being used a lot these days as sex toys. I don't know if you could say that people using them for an already "off brand" use are likely to be more careless about reading directions and such or not, but it might affect the numbers in some way.

Bippy the Beardless
12-17-2004, 11:30 AM
The sex toy users are very paranoid about the danger. Part of the reason I wanted to know quite how dangerous they really are.
Have there been any deaths caused to healthy people using TENS units? Or cases where ressusitaion was necessary to avoid death?

Excalibre
12-17-2004, 11:35 AM
I'd be surprised if anyone into BDSM enough to enjoy estim didn't do plenty of homework to keep themselves safe. BDSM culture is very big on practicing safely in every respect, and most practitioners are quite aware of the risks of all of their activities and how to minimize them. (After all, being tied up for an extended period isn't exactly without its dangers either.)

JeffB
12-17-2004, 11:46 AM
From the title, I thought, "Someone really doesn't like the decimal system."

Padeye
12-17-2004, 11:59 AM
I'd be surprised if anyone into BDSM enough to enjoy estim didn't do plenty of homework to keep themselves safe. I'm constantly suprised more people aren't killed because they think they know what they're doing. There is a very fuzzy area between wannabes and people who are seriously trained. Breath contol is an example of dangerous play. "Oh, I know when to stop." Easy to say but if a person goes into lactic acidosis the symptoms may not appear until it is already too late to prevent a death. FTR I am not into breath control or autoerotic asphyxiation. I'd prefer my bloated corpse (yeah, yeah, how could they tell) will not end up as a gallery in rotten dot com if I can help it.

I am not particularly knowledgable ab out TENS units but the circular logic of "people who do that stuff must know what they're doing and will therefore be safe," isn't going to keep anyone from getting killed. In many cases the studying consists of reading a book by a self styled expert that doesn't understand the physiological process or safety margins and has certainly never done any controlled tests. I do know that it takes a remarkably small current through the heart to kill someone. I don't know how easily that could happen with a TENS unit.

Excalibre
12-17-2004, 12:35 PM
I am not particularly knowledgable ab out TENS units but the circular logic of "people who do that stuff must know what they're doing and will therefore be safe," isn't going to keep anyone from getting killed. In many cases the studying consists of reading a book by a self styled expert that doesn't understand the physiological process or safety margins and has certainly never done any controlled tests. I do know that it takes a remarkably small current through the heart to kill someone. I don't know how easily that could happen with a TENS unit.
You're right about that, and there's no doubt folks who take a lot of risks without knowing what they're doing. (FWIW, I wouldn't be inclined to try breath play either; it's quite easy to accidentally kill someone, no matter how well you know what you're doing. I don't think it really can be done in a safe manner.) Generally, though, I think there's quite a bit of attention paid to safety in the BDSM community. That's all I meant.

bouv
12-17-2004, 01:34 PM
OK, from Here (http://www.emedicine.com/pmr/topic206.htm)


Amplitude - Current at low intensity, comfortable level, just above threshold

Pulse width (duration) - 10-1000 microseconds

Pulse rate (frequency) - 80-100 impulses per second (Hz); 0.5-10 Hz when stimulus intensity is set high


And,


Conventional TENS has a high stimulation frequency (40-150 Hz) and low intensity, just above threshold, with the current set between 10-30 mA


And Here is a listing of what different current levels do to the body. (http://www.cdc.gov/elcosh/docs/d0500/d000543/section2.html)

As it stands, the range a TENS unit operates is in the 'painful shock' level, as you found out when you picked up the pad with your hand. I'm not well versed enough in physiology and electricity to know why there is only a shock when the pads are slightly off/being picked up, and not one when in normal operation, but odds are it won't cause ventrical defibrillation (which is what most electrical deaths are from.)

Still looknig for info on actual deaths reported from TENS use, though.

Padeye
12-17-2004, 02:14 PM
Another dangerous conclusion is that a TENS unit is safe because certain of them are are approved for medical use when used by a medical professional. Consider that a TENS unit from Corky's House of Torture Devices may not have been approved by UL let alone the FDA.

I am not saying TENS units are dangerous, potentiall dangerous or even that anyone has ever been harmed by one. I am saying that a lot of the arguments that they are safe are dangeously faulty.

Joe Mahma
12-17-2004, 03:08 PM
I'm not well versed enough in physiology and electricity to know why there is only a shock when the pads are slightly off/being picked up, and not one when in normal operation, but odds are it won't cause ventrical defibrillation (which is what most electrical deaths are from.)


That would be ventricular fibrillation. Defibillation is the procedure that is performed to stop fibrillation and thereby save the patient's life.

Bippy the Beardless
12-17-2004, 04:32 PM
Another dangerous conclusion is that a TENS unit is safe because certain of them are are approved for medical use when used by a medical professional.
Well they are available over the counter at UK drug stores without prescription, so they are considered safe for use by non professionals.

LSLGuy
12-17-2004, 10:58 PM
I'd suggest that if any given TENS manufacturer is still in business, his product has killed very few (zero or 1) people at most.

I'm not suggesting the FDA would close them down, but rather they can't sell enough devices to offset more than 1 or at most 2 wrong-ful death suit settlements or payouts. After the 2nd death (at the latest) they'd have to declare bankruptcy & slink off into the night.

But no, I have no hard data on deaths from TENS units. But I'd suggest some court filings research might work better than basic Googling.

Roland Deschain
12-17-2004, 11:18 PM
I heard the inventer of the "stun gun" being interviewed on NPR's Science Friday a few weeks ago. During the interview he alleged that there had been no proven deaths from the stun guns from the shock itself (he argued that other factors such as falls and stress associated with stun gun arrests had led to some fatalities, but not the actual stun). The point is that a stun gun is more powerful by a significant factor than is the type of device you are discussing. That said you could be extra careful and attmpt to make sure that your feet are grounded more than your upper body when using the devices for sexual stimulation. In addition, it would probably be good idea not to use these devices in a bathtub (sounds like a potential episode for Myth Busters now that I think about it).

dangermouse1956
12-18-2004, 01:13 AM
The reasons that no deaths are being reported from TENS units are tucked neatly away in bouv's last post.

You see, we look at the specs for a TENS unit and we see that it can deliver 10-30 mA, then we look at the body damage chart bouv linked to (good resource, by the way, bouv!) and then we exclaim, "Holy Transcutaneous Stimulation, Batman! These suckers deliver enough current to potentially kill someone!" Ah, but the body damage charts are based on exposure to "typical houshold voltages," which means roughly a continuous sine wave of current at 120 volts RMS. Our little TENS unit, sturdy though it may be, delivers nowhere near this much energy. Read on:Pulse width (duration) - 10-1000 microseconds

Pulse rate (frequency) - 80-100 impulses per second (Hz); 0.5-10 Hz when stimulus intensity is set high


This is hardly continuous current. This means that 10-30 mA are delivered for a few microseconds (from 10 to 1000) and then these pulses are repeated only very slowly, from one pulse every two seconds up to 100 pulses per second. I haven't crunched the numbers (I will if anyone is actually interested) but this results in a tiny fraction of the electrical energy required to achieve the results in the body damage chart.

The bottom line is that TENS units are intrinsically safe because they are engineered to deliver current only in very brief pulses, and they limit the number of those pulses.

(Yes, I've oversimplified this a bit, as I didn't address available energy, etc., but I think I got the gist of it right.)

Sun Moon
06-10-2012, 01:26 AM
I regret that I found this forum so late.
I am very much interested to read the FDA article that bouv mentioned in his posting on 12-18-2004 12:09 AM and the listing of what different current levels do to the body that bouv mentioned in his posting on 12-18-2004 2:34 AM. Unfortunately, both documents appear to have been removed from their previous locations respectively.
Could anyone please advise me the updated links to these two documents? Many thanks!

voltaire
06-10-2012, 01:56 AM
I regret that I found this forum so late.
I am very much interested to read the FDA article that bouv mentioned in his posting on 12-18-2004 12:09 AM and the listing of what different current levels do to the body that bouv mentioned in his posting on 12-18-2004 2:34 AM. Unfortunately, both documents appear to have been removed from their previous locations respectively.
Could anyone please advise me the updated links to these two documents? Many thanks!

Here is the document (http://www.fda.gov/downloads/regulatoryinformation/guidances/ucm126418.pdf) that I believe his first link referred to. (I think he meant to say "a third of the way from the bottom" - as that's where TENS units are listed.)

I'm pretty sure the second link you were looking for was the exact same info as is contained here. (http://www.osha.gov/SLTC/etools/construction/electrical_incidents/eleccurrent.html)

voltaire
06-10-2012, 02:04 AM
Actually, here's an even better and more in-depth version of that second, OSHA link (http://www.oshatrain.org/courses/mods/715m2.html). (WARNING: Contains some pretty graphic pictures of some horrific electrical burns.)

Sun Moon
06-10-2012, 11:45 AM
Thank you very much Voltaire. The FDA guidance in your first link answers to a great extent my concern on the safety of TENS devices. Specifically, I am at least relieved to see that FDA considers the risk associated with TENS devices to be non-significant. However, I was hoping to see some quantitative facts and figures on what levels of current applied to which parts of the body would cause what kinds of harm to the body, like the body damage chart that Dangermouse1956 talked about in his posting on 12-18-2004, 01:13 AM.

The second link you gave me is the kind of “body damage chart” information I am looking for but with due respect, the source, OSH Academy of Malaysia, is not nearly as authoritative as FDA. It is not my intention to spark off another forum on the standard of institutes of higher learning in Malaysia but I know it as a fact that the standard has dropped drastically since the country replaced English with its national language, Bahasa Malaysia, as the teaching medium of all institutes of higher learning in/around 1975 resulting in an exodus of many top UK or US trained intellects who refused to learn the Bahasa Malaysia.

The Niply Elder
06-10-2012, 12:17 PM
Huh? OSHA is basically the premier organization protecting workers in dangerous occupations, setting basic safety standards and practices.

voltaire
06-10-2012, 01:47 PM
The second link you gave me is the kind of “body damage chart” information I am looking for but with due respect, the source, OSH Academy of Malaysia, is not nearly as authoritative as FDA. It is not my intention to spark off another forum on the standard of institutes of higher learning in Malaysia but I know it as a fact that the standard has dropped drastically since the country replaced English with its national language, Bahasa Malaysia, as the teaching medium of all institutes of higher learning in/around 1975 resulting in an exodus of many top UK or US trained intellects who refused to learn the Bahasa Malaysia.

I have no idea where you're getting this Malaysia stuff from, but here's a link (http://www.cdc.gov/niosh/docs/2002-123/2002-123b.html) to exactly the same information on a cdc.gov site, if you prefer that.

Sun Moon
06-10-2012, 09:09 PM
Oh, what I blunder that I made last night!

I am residing in Hong Kong and I wrote my posting last night, or rather this morning, at around 1 AM. I must be pretty tired then especially after reading through the materials in the two links that Voltaire gave me. I was trying to identify the source of the materials in the second link. I do not remember exactly how I navigated the net at that time which somehow brought out the homepage of OSHA Malaysia.

I apologize for my ignorance and the confusion caused

Sun Moon
06-10-2012, 09:59 PM
I think this is what I did this morning.

I went to the page indexed by the second link. After reading the materials, I wanted to know the source of the materials, OSH Academy. I clicked at the OSHA logo, the home button, and the about us button but all I got was just about the training courses. Eventually, I searched for OSH Academy on Google which is Google Hong Kong by default. The first three listings on the first page are also on the courses. The title of the fourth listing is About OSHA and it happens to be hosted by the OSHA Malaysia.