19/13ths, the Bell Curve, and Safey Margin

When Mr. Smith testified at SECU, he actually answered one of MY questions.

Excited-Delirium.com [LINK]: Why do your designers feel it is necessary to have the X26 waveform repeat at 19 cycles per second? Given that the waveform is more than perfectly capable of 'locking up' the victim with each cycle, why not repeat the shock perhaps just 2 or 3 times per second?

Mr. Colin Mayes (Okanagan—Shuswap, CPC): I'd like to ask Mr. Smith, why do your designers feel it is necessary to have the X26 waveform repeat at 19 cycles per second, given that a waveform is more than perfectly capable of locking up the victim with each cycle? Why not repeat the shock perhaps two or three times per second? What is the reason for that?

[LINK]

Mr. Tom Smith: That's a great question.

[Thanks Tom. That's why I sent it in. I'm glad you were able to review this blog so you could study-up the night before. By the way, how large is your posse?]

Mr. Tom Smith: ...Actually, that was one of the reasons the original technology did not work that well. When we actually went into the lab to determine the level we needed for incapacitation.... The discharge of our pulse is really in the range of microseconds. The actual pulse lasts for about a microsecond.

[WRONG. Even by their standards, well over 100 microseconds. And at 19Hz, five seconds by my reckoning. [LINK] and several others.]

Mr. Tom Smith: ...When you look at that, again, that release causes a single muscle contraction. What we learned in the lab and what we actually even learned in our human testing early on is that if we used anything less than about 12 to 14 pulses per second, the individual was able to have enough recovery time of their muscle to be able to function, while being jerked around, but once we crossed that threshold we got the true incapacitation, in which the muscle would lock up to the point where they were not able to continue to incapacitate.

We came up with the 19 pulses per second because that was what was required in order to get incapacitation. If we went much beyond that, we didn't see any further lock-up. That was the optimal point where we got the lock-up of the individual. They couldn't fight through it. But going beyond that, there was no further benefit.


Okay - let's review.

First, Smith must be talking about the X26 taser because he mentioned 19 pulses per second.

Smith admitted that 13 pulses per second ("12 to 14") was about the level where "true incapacitation" started. So, to make sure, they decided on 19 pulse per second. 19 as compared to 13 is +46%. That's a hell of a jump.

And he has told us the rough calibration: About 13 pulses per second is the incapacitation level. If you look at the standards, such as IEC 479-1 for example, you'll see that the incapacitation level is about 10mA, where the risk of VF for 95% of the population starts at about 30mA. Note that 5% of the normal population are more sensitive.

So if 13 pulses per second is functionally-equivalent to 10mA (incapacitation), then 19 pulses per second would be functionally-equivalent to about 15 mA equivalent (+46%).

So by these values, the safety margin smells more like 2-to-1 (30mA compared to 15mA in functionally-equivalent values), rather than 15-to-1. And don't forget the 5% of the normal population that is more sensitive. Not to mention barbs on chest versus the intent of such standards.

Excuse me Smith, your bell curves are overlapping.

It all fits.


PS: Taser's in-house 'expert' Dr. Mark Kroll, 'Independent' Director, Chair of their captive so-called Medical Advisory Board, recipient of vast numbers of TASR stock options, serial non-discloser of his close ties to Taser, once stated that the taser is "safer than Tylenol".