| 600 / | HD | SURGERY |
|
| 300 | DF | DIAGNOSTIC TESTING {38} |
| 481 | DF | .~ Cardiovascular {6} |
| 508 | DF | .~.~ Heart {4} |
| 509 |  | .~.~.~ Detecting heartbeat electric signal {10} |
| 510 | DF | .~.~.~.~> Testing artificially regulated or assisted heart |
| 511 | DF | .~.~.~.~> Fetal heartbeat |
| 512 | DF | .~.~.~.~> Orthogonal heartbeat electric signals combined to form vector signal |
| 513 | DF | .~.~.~.~> Detecting heartbeat electric signal and diverse cardiovascular characteristic |
| 514 | DF | .~.~.~.~> Sound generated by successive heartbeat electric signals to represent heart action |
| 515 | DF | .~.~.~.~> Detecting arrhythmia {3} |
| 519 | DF | .~.~.~.~> Detecting signal repetition rate {1} |
| 521 | DF | .~.~.~.~> Detecting R portion of signal waveform |
| 522 | DF | .~.~.~.~> Switching means for activating different monitoring systems, signal displays, or signal recorders |
| 523 | DF | .~.~.~.~> Signal display or recording {2} |