Re-My 92 year old Mom who has A fib and takes warfarin and digoxin. She is supposed to take her pulse prior to taking her digoxin and if it is below 60 she is not to take it. Lately she has not been able to accurately do a manual reading so we have been trying an oximeter. Her reading is always fluctuating (sometimes dipping below 60and then rising above 60) which I am assuming is Afib. Is there a better way to accurately measure her pulse.