Non-invasive blood pressure¶

Cuff blood pressure, recorded after each cuff cycle.

Stub

Imported from the time-source table; the full page is still to be written.


Name in the dataset	`Solar8000/NIBP_MBP`
Type	numeric
Device	Solar8000 monitor
Stamped by	Recorder PC clock
Unit	mmHg

Measurement space¶

Time side (as stamped): the true time lies between -80 s and -20 s from the stamp: the delay range plus the interval one value describes.

Time¶

From UTC to the stored time stamp¶

Derived from this signal's timing table; a written chain is still to come.

The clock path first (UTC to the clock that stamps or spaces the samples), then the signal's own path to its stored time. Each bar: the time shift or error the step introduces (pale) and what is left after the atlas's correction (solid), on a log scale; dashed when estimated or assumed.

UTC

The reference every chain starts from.

Recorder PC clock

sync assumed 3 ms – 900 ms · clock link, parameter

Windows time synchronisation to the hospital's time server every 8–24 h (assumed), drifting a few ppm in between. Not observable in the release: dates are shifted to 2100. No step of 0.5 s or more was found.

Recorder PC clock

transport measured 20 s – 40 s

Delay from the end of the interval a value describes to its stamp.

Stored time stamp

window measured 30 s – 40 s

The width of the interval one value or sample stands for.

Timing¶

Against the working reference. Delay: from the end of the interval a value describes to its stamp. Interval: how wide that interval is.

Form	Delay	Interval	Clock domain	Status	Evidence
as stamped (default)	20 s – 40 s	30 s – 40 s	Solar8000 numerics	measured	result 20-40 s after the cuff measurement

Combine it with other signals in the synchronisation planner.

Value¶

Its value side is still to be described.

Observations¶

Observation	Status	Summary
The blood pressure cuff often sits on the arterial line's arm	established	Many "lost pulse" events in the arterial pressure are an NIBP cuff inflating on the same arm: the pulse fades and pressure decays to 35–50 mmHg, then returns as the cuff cycle ends.

Studies¶

Study	Date	Status	Summary
Value resolution of every signal	2026-10-19	draft	How finely every waveform and numeric track in the release records its values. The SNUADC waveforms are 10-bit codes, though VitalRecorder's documentation describes the SNUADC as 12-bit; Primus waveforms use about 10 bits of 12; BIS EEG is a 16-bit grid of 0.05 µV. Numerics are 32-bit floats on decimal grids of 1, 0.1, 0.01 or 0.001, one per track; settings sit on coarser grids of 10 or 100.
Arterial line accesses in the pressure waveform	2026-10-11	current	Flushes, zeroing and blood draws leave clear signatures in the arterial pressure. A detector finds them in the waveform alone (about one access per hour) and matches 77% of lab draws to an access within 15 minutes, against 26% for random times.

Worked examples¶

Example	Side	Status	Summary
Cuff pressure against the arterial line	both	draft	12,238 cuff readings against the arterial line at the cuff's own moment, in 2,283 patients: no bias over the cohort at any pressure, but each patient's cuff reads a constant 10 mmHg (SD) above or below their line, and half the arterial readings below 65 mmHg are not below 65 by cuff.
Post-induction hypotension, from the charted start and from the devices	time	draft	The charted anaesthesia start comes a median 14 minutes before the patient is induced; measured from it, "hypotension within 20 minutes of induction" is found in 27% of 2,913 patients, against 51% from the devices' induction, and the label changes for a quarter of patients.

References¶

Goodwin A, Mazwi ML, Somer J, Schwartz SM, McEwan A, Eytan D. Blood pressure in critically ill children: exploratory analyses of concurrent invasive and noninvasive measurements. Crit Care Explor. 2021;3(12):e0586. ↗

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