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Re: [RC] accuracy of hand helt heart rate monitors - Truman PrevattWhen it is showing a "double beat" it is actually all the beats - if you listen closely in a stethoscope you will hear the four parts of the beat. The HRM is designed to only count two - on the assumption that the current flow from the other two parts of the beat are too small to be detected by the sensors. This is true in humans and these units are modified from those designed for humans. If the current flow associated with all four parts of the bear are strong enough to trigger the sensor - you get double the heart rate.I've taken a lot of pulses at rides and have seen it a couple of times. Interestingly enough it has always been on non-Arabs, both Morgans and walking horses. One time a walking horse comes in. He was calm, alert looked in great shape but his heart rate read 110 off the monitor. I put a stethoscope on him and the 110 had to be 55 since by the time I got a count on the stethoscope it was 52. My old walking horse mare had a strong heart beat and my monitor would pick up all four parts of the beat. You can usually eliminate this with your own monitor by placement of the electrodes or changing the polarity of the connection of the electrodes to the transmitter. The transmitters have a positive (red) side and an ground (black side). The connectors one the transmitter normally reflect this. Sometimes by reversing the which electrode goes to which connectors will solve the problem. With my mare I solved it by switching the girth electrode to her right side and the under saddle electrode to the left side (opposite of the recommended position). That solved the problem. If I rode with both electrodes under the saddle it also solved it. More horses - but not many - have the opposite problem. The hand helds can't detect the heart beat. That can be an issue more it seems on slab sided horses. You can normally solve that by holding the hand held monitor lower than you normally would. I've won quite a few bets when people walk into the box, I put it on and they start tell me you have to use a stethoscope on this horse, yadyad......... By the time the third yada comes out - I have the pulse, call their number and send them on :-) . Truman LAWRENCEC BENNASCONI wrote: Does any one else have a horse that has to be checked with a stethoscope? When I was training, and riding with my HRM, I thought her pulse seemed a little high, but she is not an Arab, and seemed to be fine otherwise. Now I am thinking that it wasn't reading properly. At previous rides, the handheld monitors would not read at all, this past weekend, it was about 60 degrees at the ride, I had not clipped my horse, since I was going to take it easy, and she is a short stocky Morgan from Maine who already has a longer coat than my Arabs. She was sweating more than normal, so she was actually wet enough to get a "signal", but it read in the 70s. I sponged her quickly, wetting the area behind the girth where you put the monitors, and she was at 44. I have noticed that if the HRM is not reading correctly, it will often show almost double the actual heart rate. I don't think her heart rate would have actually dropped 30 bpm that fast, I think the electronic monitor was not reading correctly. Her heart rate was confirmed by the vet at the final check, it was 40. -- "A mathematician is a device for turning coffee into theorems." - Paul Erdos (1913-1996) =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Ridecamp is a service of Endurance Net, http://www.endurance.net. Information, Policy, Disclaimer: http://www.endurance.net/Ridecamp Subscribe/Unsubscribe http://www.endurance.net/ridecamp/logon.asp Ride Long and Ride Safe!! =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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