Methods¶

A methodology group: studies that get at timing the same way.


Clinical and laboratory times	Find out what a time in the clinical and lab tables marks (an event, its documentation, a rounding), using signatures the event leaves in the signals.
Clocks carried in the signal	Use a regular rhythm inside the recorded signal (a pacemaker, a monitor's frame clock, an output or mains line) as a third clock, independent of the clocks being tested.
Data continuity	How completely each signal was recorded: where its gaps are, how long its unbroken stretches run, how it was packaged into messages, and whether a break in the stamps lost data or only moved the clock.
Delays and averaging windows	Work out how long after the event a value is stamped, and what span of signal it summarises, by recomputing monitor numbers from the waveforms they come from.
Does the waveform run on?	Test whether a waveform continues smoothly across a boundary (a record junction, a reset, a gap) to tell lost samples from lost time, and to find samples written out of order.
One event, two clocks	Find an event that two independently clocked signals both record, and read the offset between their clocks from where each puts it.
Reading the source	Read firmware, manuals and loader code to explain a timing behaviour seen in the data, or to predict one to test.
Reading the stamps	Fit drift and corrections from the record time stamps themselves, against the number of samples each record holds.
Rounding, heaping and value resolution	How far a recorded number is from the true one because of how it was written down: the resolution it was recorded at, and the coarser values people round to.