Savannah has been diagnosed with panic attacks. she and her doctors are trying to figure out how to get her panic attacks under control. she is hooked up to a machine that beeps when her heart rate speeds up so that she can concentrate on lowering her heart rate and keeping calm.
savannah's doctors are more than likely using to her control her panic attacks.

If Savanah has been diagnosed with panic attacks and her doctors are using this machine which will beep once her heart rate speeds up in order for her to be able to lower and control it better, this means that they are most likely using a biofeedback machine. These type of machines work exactly like mentioned in the question and have been used for things like these. 

You can literally find this on google of each science career and search up what type of training you need and how many years in school