9. Henry Ford was a frugal man and would never install anything on a tractor that was not essential to its operation. The fuel shut-off valve on the sediment bowl (right) is there for a reason â shut the gas off when you turn off the ignition key every time!
Sensitivity and sensitivity threshold. The electrodes do not only pace, they also sense the electrical activity at the myocardial surface. One can define the sensitivity of a pacemaker electrode as the minimum myocardial voltage required to be detected as a P wave or R wave, measured in mV. The sensitivity of the pacemaker is actually a setting on the box, where the lower the number, the more sensitive the pacemaker.
Once the pacemaker is implanted, the leads carry signals back from the heart. The pulse generator reads these signals and the batteries send electrical impulses to the heart to help pace it. Most pacemakers can sense the heart's rhythm and turn themselves off when the heartbeat is above a certain level. They will turn on again when the heartbeat is too slow. These types of pacemakers are called demand pacemakers.