Reg:Pulse sensor condition

So i just got this pulse sensor amped version from the market and i hooked it up with my arduino uno and used the program from the official site and everything worked fine, if i have my finger on the sensor it does give accurate readings and if i remove my finger the reading goes all the way to 200 which is basically noise, now i want to know if i can create a condition which would find if a pulse is detected or not, if there is no pulse i want to display "pulse not detected" immeditately. Can someone please help me out with this.
Thank you.

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Part number? Manufacturer? Link? Site?

PulseSensor.com – World Famous Electronics llc. this one
and i am using this program : https://github.com/WorldFamousElectronics/PulseSensor_Amped_Arduino

bump

The Open Hardware page says "When the Pulse Sensor Amped is just sitting there, not in contact with any fingers or earlobes or other parts, the analog signal hovers around the mid-point of the voltage, or V/2." Unfortunately, hovers and V are not described. You may have to do some experimentation with looking at the analog input value and determining when it is close to V/2.