Dear Apar,

Standard Deviation Calculator program. It is free download.

Another program is MATLAB.

Good luck,

Rafik

We use a in-house software called Fisiosinal. I'm not sure if "Kubios HRV" do the same.

Dear Rafik Sir,

Thanks for the answer.

May I understand the method of calculation using the program? Is there a specific formula which could be utilized. Another thing which I did not mention in the question posted was the data is of 30 minutes (5 min pre+20 minute intervention+5 min post). The intervention is regulated Yoga breathing with breath holding. During which we are observing a lot of fluctuation in the beat to beat BP. 

Looking forward for your guidance.