posted 08-17-2006 01:16 AM            

I've been using the Limestone system more and more and I'm increasingly happy with it, though I don't yet have the photoplethysmograph sensor

r

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"Gentlemen, you can't fight in here, this is the war room."
--(Dr. Strangelove, 1964)

posted 08-17-2006 07:59 AM            

Don is working on getting the feds up and running with the PLE. They currently have no scoring rules for them, so my guess is that they'll have to defer to the Utah (research based) criteria, which allows up to a +/-2, but again, read the Bell et al article for that info.

Stoelting's computerized system and scoring was designed by the Utah researchers, so you should be getting the most user-friendly and readable data out there, but you've got to find out what it's doing. It may be filtering somewhat, which could mean you're only going to see an amplitude decrease on the top portion - not the top and bottom. I read the Stoelting manual when I first got my Lafayette (after talking to Charles Honts as well), and if memory serves me correctly, it explains rather well what you are seeing on that channel. APA published an old article in 2005 called "What does the Plethysmograph Indicate," which explains what you're seeing and what the filtering does. I'd give it a read (Volume 34, Number 3 in 2005) after reading the Stoelting info.

posted 08-17-2006 09:26 AM            

I will be calling Limestone later today to see if I need to check any settings. I will also ask them for any manuals or documentation related to the use of the PLE. I will also try to figure out how to email the charts to you. If you know where I can get a look at the article you mentioned from 2005, I would like to read it. My email is:
dmorgan@spartanburgcounty.org

posted 08-17-2006 10:20 AM            

Would you be willing to email me the PLE article?

I'd like to read it and I could post a secured link for other.

r

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"Gentlemen, you can't fight in here, this is the war room."
--(Dr. Strangelove, 1964)

posted 08-17-2006 12:48 PM            

It works great for me.

Limstone prints ever page as a separate print job, so you end up with a whole bunch of .pdf -s that need to be concatenated. uhgh. They could fix this.

r

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"Gentlemen, you can't fight in here, this is the war room."
--(Dr. Strangelove, 1964)

posted 08-24-2006 03:43 PM            

Sorry for the delay - had to triage my to-do list.

For anyone who's interested...

here is a flash doc of a powerpoint for a training next week
http://www.raymondnelson.us/training/PCSOT_trng_for_POs.swf

beware - it's 150+ slides

here is a 26 page .pdf
http://www.raymondnelson.us/training/PCSOT_8-30-06.pdf

r

------------------
"Gentlemen, you can't fight in here, this is the war room."
--(Dr. Strangelove, 1964)

posted 08-25-2006 05:23 PM            

Thanks Barry,

I think I change the GSC slide - that one was recycled from a while ago. I've been under the impression that all the newer instruments monitor conductance, though I did hear a while ago that Axciton may use a combined measure or resistance and conductance. Its probably not that important to POs.

I recently added all the stuff on questions after I was informed by the head of probation services that their survey indicated a desire for more training around questions and targets. (always good for controversy.)

r

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"Gentlemen, you can't fight in here, this is the war room."
--(Peter Sellers as President Merfin Mufley in Stanley Kubrick's Dr. Strangelove, 1964)

posted 08-25-2006 05:58 PM            

Since this is a PLE thread, and we're off topic, does Axciton have a PLE sensor? If so, how well does it work?

posted 08-25-2006 07:35 PM            

A small light is placed (inside some type of clip that fits over the finger) on the fingertip. Next to the light is a light sensor, and it measures how much light is reflected back from the finger. The amount of blood in the fingertip determines how much light gets through.

When a person experiences FFF, blood is directed away from the fingers (and feet, digestive system, etc) towards those muscles and organs that need fuel (blood) to fight or flee or threat. We measure that reaction with the PLE. During a reaction, you see a reduction in pulse amplitude (which looks very similar to the cardio reading) for a brief period of time.

posted 05-11-2007 08:47 AM            

Dan,

How have you been making out with yours? Did you ask how Limestone filters theirs? What kind of scores are you getting with it?

posted 05-11-2007 09:04 AM            

One big reason that I was having trouble with my understanding of the PLE tracings was that for some strange reason, my tracings in the "view chart" screen were inverted from the true tracings during the test. As you can imagine, this caused me great difficulty. I stopped using the PLE for several months until I figured out what was going on. Limestone corrected this very quickly. Since then, I still get the usual: either the PLE works great or it doesn't work at all. There seems to be very little in between. The Limestone PLE is an earclip, but they are coming out with a finger clip that is supposed to be much better as well. I am looking forward to that. Maybe it is the earclip as opposed to the fingerclip, but the tracings that I currently get are similar to cardio tracings in that reactions appear to be in amplitude as opposed to narrowing of the tracings that I had seen in Don's presentation. If the tracing looks clearly like a reaction then I use it. If I have any doubt I do not. I would say that I use the tracing for scoring about 25% of the time. I also score it as +/- 1. I do appreciate your help and the articles. I am more comfortable with it now, but I think that the new device coming from Limestone will be much better (I hope).

posted 05-15-2007 09:07 AM            

Does anyone know why we refer to it as a photoplethysmograph, when the technology appears to be that of a standard pulse-oximeter?

r

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"Gentlemen, you can't fight in here. This is the war room."
--(Stanley Kubrick/Peter Sellers - Dr. Strangelove, 1964)

posted 05-15-2007 10:27 AM            

Danny

posted 05-15-2007 11:24 AM            

It occurs to me that

Glutiokineticotransducomograph = whoopey-cushion...

I prefer the Limestone trademark name - StingRay.

r

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"Gentlemen, you can't fight in here. This is the war room."
--(Stanley Kubrick/Peter Sellers - Dr. Strangelove, 1964)

posted 05-15-2007 01:51 PM         

Sorry Dan, I didn't mean to derail your thread. It's Ray's fault.

posted 05-15-2007 02:44 PM         

"There simply is no better oral countermeasure detection device in the field, period." --Roger Ebert, Sun-Times

[This message has been edited by stat (edited 05-15-2007).]

posted 05-15-2007 03:26 PM            

quote:

---

cool. I don't suppose those guys ever gave you any credit, did they?

---

I wouldn't say that. I got my name used - and its kind of cool that it could actually imply other meaning as well.

The folks at Limestone have been a pleasure to work with. They are smart, responsive, progressive, and interested in a good product that is grounded in an understandable documented science (sorry if I sound like a cheerleader - they don't pay me for that, but they are good folks).

After looking at Limestone's rank scoring tool at APA last year, I boasted arrogantly that it wouldn't be difficult to use common inferential statistics to evaluate the test results. So, they encouraged me to work on that for them, which I did.

Then, when the opportunity to combine the efforts of that project with the Mark Handler's ideas for a redesign of Don Krapohl and Barry McMannus' Objective Scoring System, Jamie, Tyler, and Brad at Limestone readily supported that idea too. So, I think it might be fair to say they have been supporters of a lot of the things I've been working on this past year, and I have spoken regularly with them about that project.

--------

I have to admit I've tried the oral countermeasure bonnet.

I had to bite quite hard to get reactions, but it works, and its possible to do without being observed.

r

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"Gentlemen, you can't fight in here. This is the war room."
--(Stanley Kubrick/Peter Sellers - Dr. Strangelove, 1964)