K-3 Indicator

The K3 indicator was a medical instrument used in the 23rd Century.

Used exclusively in the body function panel, it assisted a doctor in reading a patient's vital signs. This marker, not normally active, measured the level of pain experienced by a patient.

It was sometimes referred to as the "brain wave index", or was said to show "brain pattern"s or "delta waves." More accurately, this indicator showed the electrical activity of the brain, drawing a correlation between pain levels and brain activity.

Example: While treating Spock for a flying parasite infiltration in 2267, Doctor McCoy activated this indicator to show how much pain the creature was inflicting on the science officer.