That's the idea. Measuring pain is a very abstract way to measure how humane an execution is. When I broke my wrist and went to the hospital, they asked me to rate my pain on a scale from one to ten, and I said three. I don't know why I said three or what answer I should have given, only knowing that one was the least painful and ten was the most painful. I imagine many people who have been executed might have the same difficulty (and keep in mind that people on death row aren't known for being honest).
So I decided, if we're going to execute criminals, and their executions must be humane, make an execution process that kills the person as quickly as possible. We could use a pulse sensor or an EKG to see if the process worked or not. If it caused instant death, great. If not, we could quickly and easily deliver another blow. Other sensors could be added to the execution device/instrument to make it more likely to cause instant death the first time, such as accelerometers.
Other execution methods take too long. Gas chambers and lethal injection and hanging take several minutes. So do electric chairs. And the problem with electric chairs is that they make the body too hot to touch, so you can't listen to their heart with a stethoscope, and any pulse or EKG sensors would be fried. Even decapitation can take twenty or thirty seconds to cause death.
Another advantage of executing criminals with blunt force trauma to the head is that the execution device could easily be reused for multiple criminals, unlike the gas for gas chambers or the drugs for lethal injection.
