CardioQ¶

Deltex CardioQ oesophageal Doppler: pressure and flow waveforms.

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


Type	monitor
Clocks	CardioQ clock

Device documentation¶

VitalDB connection guide: Deltex CardioQ

Variables¶

Variable	Type	Stamped by	Spaced by
CardioQ pressure and flow	waveform	Recorder PC clock	CardioQ clock

Scale factors and resolution¶

Waveform scale factors. Physical value = offset + stored code × gain, one row per stored configuration. A factor shown wrong has its correction in Corrected to.

Track	Unit	Stored as	Rate	Gain / offset	Recordings	Corrected to
`ABP`	mmHg	float32	180 Hz	1 / 0	29	—
`FLOW`	cm/sec	float32	180 Hz	1 / 0	29	—

Waveform resolution. Observed span is what the data reach, and the whole bits needed to store it; converter is our estimate of the device's resolution (never less than the span), with its evidence. The step is in the physical unit, with the corrected gain where the stored one is wrong.

Track	Step	Observed span (codes used)	Bits to store span	Converter (estimate)	Evidence
`ABP`	1	codes -100–414 (497 used); 2 corrupt samples outside	10	unknown, at least 10 bits	whole mmHg over 515 values: a display resolution
`FLOW`	1 (0–255), 2 (256–510), 4 (512–1016)	values 0–1016 (509 used): codes of a 9-bit segmented scale	9	unknown	a 9-bit segmented code, steps 1, 2 and 4 (CardioQ FLOW uses three scales (a segmented code))

Numerics. Stored as floats with gain 1. Grid is the coarsest decimal step holding 99% of records; the share on the next coarser grid shows heaping (by chance about 1/2, 1/5 or 1/10).

Track	Unit	Stored as	Interval	Recordings	Grid	Share one step coarser	Rounding	Observed range	Note
`CO`	L/min	float32	3.68 s	29	0.1	0.35	—	0 to 114	—
`FTc`	—	float32	3.68 s	29	1	0.35	—	0 to 1496	—
`HR`	/min	float32	3.68 s	29	1	0.35	—	0 to 540	—
`MD`	—	float32	3.68 s	29	1	0.35	—	0 to 5013	—
`SD`	—	float32	3.68 s	29	0.1	0.35	—	0 to 933	—
`SV`	mL	float32	3.68 s	29	1	0.35	—	0 to 7297	—
`CI`	L/min/m2	float32	3.81 s	28	0.1	0.35	—	0 to 15.8	—
`FTp`	—	float32	3.81 s	28	1	0.29	—	0 to 2683	—
`MA`	—	float32	3.81 s	28	0.01	0.34	—	0 to 191.76	—
`PV`	—	float32	3.81 s	28	0.1	0.33	—	0 to 254.3	—
`SVI`	ml/m2	float32	3.81 s	28	0.1	0.34	—	0 to 844.3	—

Observations¶

Observation	Status	Summary
CardioQ FLOW uses three scales (a segmented code)	likely	CardioQ FLOW values step by 1 from 0 to 255, by 2 from 256 to 510 and by 4 from 512 to 1016: 509 values, a 9-bit code whose step doubles in each upper segment, as in µ-law and A-law companding or a small floating-point format (an exponent and a 7-bit mantissa). Below 256, even values outnumber odd ones by 40 to 230 times.

Studies¶

Study	Date	Status	Summary
Gaps and unbroken segments in every waveform	2026-10-19	draft	Every gap and every unbroken segment in the 6,388 recordings, per waveform. The curves are not smooth: a cliff at about 18 s in every device marks the recorder's pauses, SNUADC segments stop at 5 hours, Primus segments at about 2.0 hours and BIS segments at about 2.3 hours (each device's correction cycle), and BIS's short gaps grow with the time since the last one (clock resynchronisations, not lost data).
Message sizes and the steps between records	2026-10-19	draft	Every record in every waveform: SNUADC writes messages of 100 samples (0.2 s), Primus 30 (0.48 s), BIS 16 (0.125 s), CardioQ no fixed size. Backward steps outnumber gaps by about a hundred to one and come from a few recordings with duplicated or interleaved records. Primus gaps are whole lost messages; most SNUADC and BIS gaps are not.
What each break in the stamps is	2026-10-19	draft	Every step between waveform records in the release, sorted by mechanism: written twice, a SNUADC clock reset, interleaved streams, a pause shared by every device, whole messages, less than a message, or a fraction of a message beyond whole ones. A continuity test with controls shows which classes lose data: shared pauses and most longer SNUADC gaps do; steps under one message, and SNUADC's lone one-message steps, mostly do not.
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.
Closing loops in the timing graph	2026-10-13	current	Where two independent routes reach the same clock, the offsets around the loop must sum to zero. Three measured loops close within their noise; the BIS loop closes up to a constant latency; the proposed EMR loop is not a loop at all.
Rare devices against SNUADC	2026-10-13	current	CardioQ, EV1000, Vigileo and Vigilance each get a link to the SNUADC timeline: beat matching for the CardioQ, mean arterial pressure alignment for the EV1000 and Vigileo, and a long-window fit for Vigilance's averaged heart rate.
Clock corrections in every file	2026-10-11	current	A scan of all 6,388 files for the jumps where the recorder re-synchronises a device's stamps. Each device type has its own correction signature; only SNUADC and BIS correct clearly enough to measure their drift.

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