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Solar8000 monitor

GE Solar 8000M patient monitor: numerics (HR, pressures, SpO₂, NIBP) and the analogue outputs SNUADC samples.

Stub

Imported from the time-source table; the full page is still to be written.
Type monitor
Clocks Solar8000 clock

Device documentation

Variables

Variable Type Stamped by Spaced by
Solar8000 ART and CVP numerics numeric Recorder PC clock —
Solar8000 heart rate numeric Recorder PC clock —
Non-invasive blood pressure numeric Recorder PC clock —
Solar8000 pulse rate (PLETH_HR) numeric Recorder PC clock —
SpO₂ numeric Recorder PC clock —

Scale factors and resolution

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
HR /min float32 2 s 6,388 1 0.21 truncate (Solar8000 heart rate is truncated, not rounded) 0 to 223 —
PLETH_HR — float32 2 s 6,387 1 0.2 — 6 to 300 —
PLETH_SPO2 — float32 2 s 6,387 1 0.74 — 29 to 100 —
VENT_MAWP mbar float32 2 s 6,300 1 0.19 — -6 to 34 —
ETCO2 mmHg float32 2 s 6,295 1 0.22 — 0 to 86 —
INCO2 mmHg float32 2 s 6,295 1 0.22 — 0 to 46 —
FEO2 % float32 2 s 6,278 1 0.24 — 12 to 100 —
FIO2 % float32 2 s 6,278 1 0.24 — 16 to 100 —
RR_CO2 /min float32 2 s 6,203 1 0.21 — 0 to 53 corrupt values to 822
VENT_RR /min float32 2 s 6,051 1 0.22 — 0 to 60 —
VENT_MV L/min float32 2 s 6,049 0.1 0.2 — 0 to 20.1 —
ST_II mm float32 0.075 s 6,008 0.1 0.28 — -9.6 to 8.6 —
VENT_TV mL float32 2 s 5,985 1 0.2 — 7 to 2450 —
VENT_PIP mbar float32 2 s 5,984 1 0.19 — -2 to 58 —
VENT_PPLAT mbar float32 2 s 5,961 1 0.2 — 0 to 50 —
VENT_INSP_TM sec float32 2 s 5,940 0.1 0.21 — 0.6 to 3.5 —
BT C float32 2 s 5,935 0.1 0.2 — 1.1 to 39.7 —
NIBP_MBP mmHg float32 2 s 5,723 1 0.2 — 0 to 222 —
NIBP_DBP mmHg float32 2 s 5,708 1 0.2 — 0 to 197 —
NIBP_SBP mmHg float32 2 s 5,708 1 0.2 — 0 to 274 —
VENT_SET_TV mL float32 2 s 4,261 10 0.23 — 30 to 850 —
ART_DBP mmHg float32 2 s 3,535 1 0.2 — -96 to 348 —
ART_SBP mmHg float32 2 s 3,533 1 0.2 — -88 to 347 —
ART_MBP mmHg float32 2 s 3,532 1 0.2 — -84 to 349 —
ST_V5 mm float32 0.987 s 3,353 0.1 0.29 — -10.9 to 10.7 —
ST_I mm float32 0.724 s 3,062 0.1 0.48 — -10.6 to 12.4 —
GAS2_EXPIRED % float32 2 s 3,053 0.01 0.94 — 0 to 10.9 —
GAS2_INSPIRED % float32 2 s 3,053 0.01 0.92 — 0 to 12.5 —
ST_III mm float32 0.723 s 3,051 0.1 0.33 — -11.5 to 9.1 —
ST_AVF mm float32 0.893 s 3,024 0.1 0.27 — -7.2 to 6 —
ST_AVL mm float32 0.991 s 3,024 0.1 0.3 — -6 to 6.3 —
ST_AVR mm float32 0.991 s 3,024 0.1 0.3 — -6 to 6.3 —
VENT_SET_PCP cmH2O float32 2 s 2,754 1 0.85 — 12 to 61 —
VENT_SET_FIO2 % float32 2 s 2,255 10 0.049 — 21 to 100 —
CVP mmHg float32 2 s 1,462 1 0.2 — -78 to 347 —
RR /min float32 2 s 1,294 1 0.22 — 0 to 200 —
VENT_MEAS_PEEP hPa float32 2 s 173 1 0.93 — -3 to 33 —
FEM_DBP mmHg float32 2 s 106 1 0.2 — -96 to 349 —
FEM_MBP mmHg float32 2 s 106 1 0.2 — -70 to 348 —
FEM_SBP mmHg float32 2 s 106 1 0.2 — -89 to 348 —
PA_DBP mmHg float32 2 s 81 1 0.2 — -90 to 344 —
PA_MBP mmHg float32 2 s 81 1 0.19 — -75 to 344 —
PA_SBP mmHg float32 2 s 81 1 0.2 — -75 to 348 —
VENT_COMPL mL/cmH2O float32 2 s 1 1 0 — 14 to 14 —

Observations

Observation Status Summary
Monitor numerics describe the past, never the future established Every monitor numeric describes a window of 3–30 s or more that ended 1–9 s before its stamp. None is stamped before its data exist, so the stamps already respect the availability rule.
Numeric delays are fixed within a case but differ between cases established A numeric's delay does not drift through a recording, but 40–70% of its variance lies between cases. One delay per case describes it; one delay for the whole dataset is wrong by up to about 2 s.
Solar8000 ST records are written twice established Every Solar8000 ST_II record is duplicated at the same stamp (0–20 ms apart).
Solar8000 heart rate comes one poll early or late established Heart rate reaches the recorder about 1.9 s or about 4.2 s after its window ends, one 2 s poll apart. The group belongs to the recording PC and stays fixed through a case.
The ECG→PPG delay is a sawtooth established Inside the oximeter the PPG content creeps 18–52 ppm against its 30 Hz frames; every 11–31 minutes a frame repeats and the delay jumps up by 33 ms. The rate is fixed per recording setup.
The PLETH arrives about 0.4 s late established Raw R-to-PPG-foot pulse arrival time in VitalDB has a median of 0.64–0.71 s, about 0.4 s more than physiology: the monitor's buffering and filtering. One delay fits the whole release: no clusters by setup, SNUADC port or case order (One device delay for the PLETH across the release).
The Solar8000 relays the Primus's ventilation numbers established Solar8000 ETCO₂, RR_CO2, VENT_PIP and VENT_RR change only every 6–8 s: they are Primus values passed on through the Solar8000's 2 s polling, not measured by the monitor.
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.
The oximeter's frame clock is a fingerprint of the setup established The rate of the oximeter's 30 Hz frame clock against the SNUADC sample clock is fixed per recording setup (+7 to +92 ppm across setups) and repeats within about 2 ppm inside a recording, so it identifies the hardware a recording was made on.
The plethysmogram is built in 30 Hz frames established The SNUADC PLETH waveform comes from the oximeter in 33.3 ms frames, smoothed to 500 Hz. Its content changes once per frame, on the oximeter's own clock, about 0.4 s after the finger.

Studies

Study Date Status Summary
The SNUADC clock through the Solar8000 numerics, whole release 2026-10-19 current On the SNUADC's own sample count, the delay from the waveform to the PC-stamped Solar8000 heart rate and mean arterial pressure ramps at the SNUADC's drift against the PC, measured without its stamps or resets. In recordings with whole reset intervals it agrees with them (−63 ppm; median difference +1.5 ppm, 581 recordings). It is too noisy per recording, and in recordings under about 4 h its rate is biased toward zero, so it cannot yet speak for recordings without resets.
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.
One device delay for the PLETH across the release 2026-10-18 current The stored ECG-to-PLETH delay was measured in 5,536 recordings, to the foot and to the steepest upstroke of each pulse. It has one peak (655 ms to the foot, 715 ms to the upstroke, in the median recording), no clusters by recording setup or SNUADC port, and no shift along the case order: one global device delay, 385 ms with an adopted R-to-foot finger PAT of 270 ms, fits the whole release, as Ruffolo et al. found in their own data.
Identifying the recording setup of every case 2026-10-18 open Recognising which equipment made each recording, from its serial ports and, where those fall short, from clock fingerprints, so that per-setup values can be used for every case.
Monitor clocks in the waveforms' spectral lines 2026-10-17 open Differences of the raw converter counts show lines from the monitor's analogue outputs: 240 Hz in arterial pressure and plethysmogram, and a 30 Hz family in the plethysmogram alone. Each measures a monitor clock against SNUADC.
SNUADC against the PC-stamped heart rate 2026-10-17 current The Solar8000 heart rate is stamped by the recorder on arrival, so the delay from the ECG to it, on the ECG's raw sample count, ramps at the SNUADC clock's rate: −65.3 ppm, against −66.7 ppm from the stamp model. Two independent routes agree.
Recorder PC clock steps and recording pauses 2026-10-17 current A step of the recorder PC clock would move every device's stamps at once. Searching all 6,388 files for such simultaneous jumps found none of 0.5 s or more; what moves everything together is recording pauses.
Two heart-rate delay groups, one poll apart 2026-10-13 current Solar8000 heart rate reaches the recorder either about 1.9 s or about 4.2 s after its window ends: one 2 s poll apart. The group belongs to the recording PC, stays fixed through a case, and on some PCs varies from case to case.
Numeric delays are fixed within a case, different between cases 2026-10-12 current With each numeric's algorithm held fixed, delays were fitted for every case and every 30-minute block. They do not drift within a case, but 40–70% of their variance lies between cases, so a single population delay is wrong by up to 2 s for HR and 1 s for the others. Each case gets its own delay label.
How the monitors compute their numbers 2026-10-12 current Recomputing each monitor numeric from its own waveform finds a short, simple algorithm for every one (a median, an exponential average or a time mean over 3–30 s) and a delay of 2–9 s behind the newest data it uses. No value is stamped before its data exist.
The PPG hardware delay and the adopted pulse arrival time 2026-10-12 current VitalDB's raw ECG→PPG pulse arrival time is about 0.4 s longer than physiology. Splitting it into a hardware delay (one value for the release; One device delay for the PLETH across the release) and a physiological part needs an adopted value from studies that sampled ECG and PPG on one clock: about 270 ms for anaesthetised adults.
SpO₂ and pulse rate latency from step events 2026-10-12 current SpO₂ cannot be recomputed from one plethysmogram, so its timing comes from events that change the PLETH abruptly. SpO₂ lags the recorded PLETH by about 4 s and then smooths over roughly 10–20 s.
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.
Arterial pressure as a check on the PPG correction 2026-10-11 current Arterial pressure is sampled by the same converter but has no frame and no sawtooth, so every PPG slip leaves ECG→ABP unchanged. Against it, detected slips are 97–100% real and tier A leaves about 2 ms of drift mid-tooth.
Where the PPG sawtooth stops 2026-10-11 current In some stretches no slip comes although several were due. The PPG delay there is flat, not hidden: the monitor keeps framing, and only the content's drift against the frames has stopped.
The PPG's 30 Hz frame clock 2026-10-10 current ECG and PPG fiducials resolve to one 2 ms sample, but PPG fiducials taken on raw samples lock to a hidden 33.3 ms frame grid. Scanning for it finds the oximeter's frame clock to about 1 ppm, a fixed fingerprint of each recording setup.
The PPG sawtooth and its correction 2026-10-10 current The ECG→PPG delay creeps at 18–52 ppm and jumps up by one 33.3 ms frame at each slip, every 11–31 minutes. A tooth-by-tooth model removes it; where the correction is confident it is essentially exact on injected test data.

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