I've been hearing now that it's possible for some instruments to measure some of your emotions.

 

For example, they can tell if you are happy or sad, but how is this accomplished? My guess is through a correlation, they get a particular brainwave and ask the person how they feel and the person knowing how they feel would tell them, and they can use this again, when the brainwave manifests they know how the person is feeling.

 

What about stress though. Is there any machine that can quantify how much you are feeling, say could group it on a 1 to 10 scale, where 1 in the mildest stress possible, and 10 is on the breaking point, on the verge of having a nervous breakdown, so it could be objectively measured through measuring the intensity of certain things, heartbeat, blood pressure, breathing rate, etc.

 

The thing is, only certain stress manifests at certain times. If you went in for a brainwave at the hospital and felt relatively calm, it would show you as having not a lot of stress, but if you had a helmet on at work that you wore for the whole day, it could measure it throughout the day according to that activity. So, if you doctor ordered a stress test, the one at the hospital wouldn't be very accurate.

No but the doctor could order a 24 hour test in which you would wear a device for a whole day, and monitor your stress levels. They can do this with your blood pressure.