Science Buddies: "Ask an Expert"

I am doing a project on the effect of caffine in hamsters. How can you measure the heartbeat or pulse of the animal without having to bring it to the vet? I cannot use a stethoscope becasue the heartbeat is too fast to count since the normal heartbeat of a hamster is 450 beats per minute. Is there any other way?

Hi,

In your shoes, to measure a hamsters heartbeat I would place a microphone against the hamsters chest, assuming it will tolerate this, and display the output of the microphone on a time vs. amplitude graph on a computer. There are many tools to do this, and many school physics labs have all you would need You could also feed the microphone output to a frequency counter, though this is less likely to be standard school equipment. You can also investigate LEGO programmable bricks. I have seen a report that one of their standard projects is to measure a person’s heartbeat, so it might measure a hamster’s heart rate just as well- though I have no real information on this.

I hope this helps. I am afraid you are on your wn to invent this solution unless one of our other experts has more knowledge about this than I do.

Best regards,

Barrett L. Tomlinson

I think Mr. Tomlinson has a great idea, putting a microphone on the chest of a hamster. The software idea is also really good, but if you are unable to find that software I would suggest just using microsoft sound recorder, which comes with all PC computers. On a PC, go to start, programs, accessorries, entertainment, voice recorder. Then hook up your microphone to your computer and record the heartbead. Even if you only record the heartbeat for a second or two, you can calculate the beats per minute. You would count the number of peaks on the program by keep playing the recording over and over again until you count them all. Then you can make a proportion, for example (10 beats/1.2 seconds)=(x beats/ 60 seconds). Then cross multiply, so 1.2x=600 and x=500 beats per minute. If you need any more help with the math or other ideas let me know.

good luck,
scienceexpert123

Hi,

Just to add to what has already been said: The heart rate of a hamster is likely to be very high, somewhere around 10-15 beats per second, if the similarly-sized birds I study are any indication. Recording the heart beat might work, but you would need software where you could slow down the recording enough to where you could count the beats. You will also need a good, clear signal, which may be impossible if the hamster is active. It will be much more difficult than measuring heart rate in a human!

Remember that any project using vertebrate animals may need additional permission forms, which usually have to be filled out before the work starts--talk to your teacher about this before you do any research!

Hi,
Just to echo Melissa's post, it is EXTREMELY important that you obtain prior approval by the Scientific Review Committee or some other scientific board before you work with vertebrates of any kind. Giving caffeine to hamsters could be considered "harmful", and you should definitely consult your teacher on how to minimize the effect of harm to your subjects. Best of luck!