Accuracy HRM More

[Roger Rittenhouse-vmaxept <roger@vmaxept.com>]

I see more issues.. should have read it all..
You CANNOT use TWO transmitters on the same horse at the same time.. YES
THE SIGNALS WILL INTERFERE

If you have a hrm on the horse -- the pulse taker cannot use the
handheld.. must disconnect a lead from the transmitter.. or take off the
belt.. it like two radio stations on the same freq..
make sense
cant use two monitors on the horse at the same time

and again-- if the pulse taker did not practice first---...

some horses can be read on the left and the right side.. some only the
left.. it has to do with the strength of the ekg..NOT loudness of the
heart- but the pacer that triggers the heart.
and has to do with skin impedance..
I recommend ONLY taking the pulse on the LEFT side..
and yes you WILL have to leave it on the horse for a few update cycles..
Golly some manual checks take a minute that is 4 - 15 second counts to
get it right.. 
I recommend AT LEAST 15 seconds better for 30.. and I don't call it
until I see the SAME HR or a going down hr for that time- IF it goes UP
--that may well indicate the horse is excited or having a problem..
THAT has happened to me.. the HR was higher then it was when I stepped
in the gate.. and they were on me fast... but wait 15 or 30 sec.. as one
would do with a stethoscope and let the readings settle.
  
more points
IF the horse has an ekg anomaly SOMETIMES the electronic hrm used
today-- that is the human running devices - will NOT give a correct
reading..
IF that be the case- the rider should insure mgmt provides for a
stethoscope pulse taker at the vc.
when ever I am in that position I ALWAYS carry one to offer a recheck or
let the rider take it-- if they disagree.
Yes there are rides where the checker using the handheld cannot take the
pulse .. but the person in charge of the vc should be able to do that
task.
I have checked over 500 horses with this device.. and if I had one that
did not give a correct reading - I cannot recall,
A number of  vets in the east went to many rides took the  pulse AT the
SAME time with the handheld and the stethoscope.. to confirm the
readings..one was Dwight Hooten the EAST TEAM Vet for Panam..it was his
call to use the hrm for the pulse before we took the horses in - he
rechecked none at the line, the only time he did hr reading was with
horses that were in question. I think all but ONE rider called the hr
using the device.. none were hit with errors.

NO --electronic devices may not work on ALL horses-- but then can a
novice or even experienced pulse take  find the correct pulse on a horse
that adds or skips beats.. or has an irregular rhythm??
AND YES the ride vet does need to listen to the heart sounds.
I was charged at one ride to listen for hr problems and report such.. my
comment-- that was the vets job.. i read heart rates - counts only -- 
or i don't do the job.. its difficult enough to get good pulse takers--
then to place on them the responsibility to evaluate the quality of the
hr
and look for inversions and look for thumps .. don't think so
the vc criteria is the hr  that's all the checker is responsible for.
not to play mini pre vet.

More on the so called 'calibration' comments.
NONE of these devices can be 'calibrated' - the device is time based on
a digital clock- same as the std time watches. It is as accurate as we
need -- do you really need more then +/- 1 bpm? IF a person wanted to
test it- you need to get a very accurate clock that is quartz driven- a
motor, say your Rolex. Place the monitor rec on top of the watch and
note the reading - should be 59 to 61. I know of no other way to get a
field accuracy verification. It then is as accurate as the analog watch
one would use to make the 15 sec count.

My point is not weather the use of an electronic device is or is not a
proper or correct method to obtain the horse's hr,
but to explain the use and  function - defend the accuracy, consistency
and reliability of the tool.

How it is used is up to the riders and ride managers, that is another
issue, more politics then technical.
I offered technical facts about how the device works and I have the
proof from 'many' users to certify the accuracy.



Roger  (no letters here)


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