How do you work out beats per minute (bpm) of a heart rate when using a stroboscope?

I am currently working with Daphnia magna (small marine crustaceans) and need to monitor their heart rate using a stroboscope, as it beats to quickly to count individually. Using a stroboscope and a cold light source, I should be able to change the frequency of the stroboscope in order to make the Daphnia heart appear to be %26#039;frozen%26#039;. Using this information, how do I finally work out bpm using the frequency?

Thanks beforehand if anybody could help me out!

How do you work out beats per minute (bpm) of a heart rate when using a stroboscope?

Ideally, count the beats for one full minute, as this is the most accurate and is likely to pick up any skipped or missed beats. But, you can count the beats for 30 seconds and then multiply x%26#039;s 2 ( this will give an estimate of a full minute= 60 secs.). At least, this is how the heart rate can be estimated with humans. I hope that this is helpful.