Comparison of Intraoperative HR and RR Acquired Via ATLASense Raphael PolyMonitor and Standard Intraoperative Monitors: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Comparison of Intraoperative HR and RR Acquired Via ATLASense Raphael PolyMonitor and Standard Intraoperative Monitors (NCT05291949), a na na study. The primary outcome is Heart Rate (HR).

2. Clinical Question

3. Trial Design

This completed study was registered as NCT05291949 and described as an observational comparison of intraoperative monitoring devices. The registry lists a single-group model, no allocation, and no masking. Participants received ATLASense RAPHAEL PolyMonitor monitoring for the duration of surgery; standard intraoperative monitors served as the reference for the measurement comparisons. Thus, the design concerns paired measurements in a monitored group rather than a randomized comparison between treatment arms.

The registry gives an enrollment of 70. It identifies Henry Ford Health System as the sponsor, with a start date of 2021-10-18 and a primary completion date of 2022-01-17. The study status is completed. The listed phase is NA, consistent with the record describing a device-monitoring comparison rather than a drug treatment trial.

The primary endpoint concerns heart rate, measured minute by minute by the PolyMonitor and standard monitor over the entire duration of surgery. The primary analysis population includes only participants enrolled after the interim analysis who had heart-rate data available from standard intraoperative monitors. The registry does not report the number in that analysis population or explain further how it was defined.

The study description also names data collection gaps, mean arterial pressure, core body temperature, non-invasive blood pressure, alert validation, and practical logistics as areas of interest. The registry lists five outcome measures and one analysis. The record does not report detailed procedures for device placement, data synchronization, or adjudication of discrepant readings, so those operational details cannot be inferred from the design description.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Analysis population for the primary outcome, as defined in the registry: This only includes participants who were enrolled after the interim analysis, and who had HR data available from the standard intraoperative monitors.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Heart Rate (HR), measured over Entire duration of surgery.

The primary endpoint is the Spearman correlation coefficient for minute-by-minute heart-rate measurements from the ATLASense RAPHAEL PolyMonitor and standard intraoperative monitors. Measurements were considered across the entire duration of surgery. The endpoint description specifies a mean-type summary and standard deviation, but the registry’s stated correlation coefficient is the key measure of association between the two measurement series.

Spearman correlation assesses whether paired values tend to rank in a similar order. It is useful when an analysis focuses on monotonic association and does not require the relationship to be expressed as a straight line. In this context, a stronger positive association would indicate that higher readings on one monitor tend to occur alongside higher readings on the other.

Correlation is not a direct measure of agreement. Two monitors can track rises and falls together while having systematic differences in their readings. Assessment of interchangeability would require information about the size and pattern of measurement differences, not correlation alone. The registry record does not report a numerical correlation estimate, a confidence interval, or a p-value for this endpoint, so the strength and precision of the observed association cannot be described from the record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a continuous measurement endpoint based on paired heart-rate readings. Statistical interpretation depends on what the chosen summary measures, which observations enter the analysis, and how incomplete or repeated measurements are handled. The record identifies the endpoint and a restricted analysis population, but does not report a detailed statistical analysis plan or numerical result.

What does Spearman correlation measure?

Spearman correlation is a rank-based measure of association. Rather than focusing on the exact numerical distance between every pair of readings, it assesses whether observations that are relatively high for one measurement source also tend to be relatively high for the other. It can characterize a monotonic relationship, meaning that values generally move in the same direction, even when the relationship is not adequately described by a straight line.

For monitoring-device comparisons, this can be informative about whether the series track one another. However, the coefficient does not quantify the typical difference between devices, nor does it show whether any difference changes across the range of heart rates. A systematic offset can coexist with strong correlation. Therefore, a correlation result should not be read as proof of close agreement or interchangeability. The registry record does not describe a separate agreement analysis or its results.

Why does the analysis population matter?

The registry states that the primary endpoint includes participants enrolled after the interim analysis and with heart-rate data available from standard intraoperative monitors. Availability of the reference measurement is necessary for a paired comparison, because the endpoint depends on readings from both monitoring sources. At the same time, restricting analysis to those with available data can affect which observations are represented. If data availability is related to the patient, procedure, monitor performance, or operating conditions, the analyzed set may differ systematically from the full enrolled group.

The record does not report the size of this primary analysis population or describe the reasons that standard-monitor data might be unavailable. It also does not describe how many minute-by-minute observations were contributed by each participant, how repeated observations were weighted, or whether correlation estimates accounted for measurements clustered within participants. Repeated readings from the same person are generally related rather than independent. As a general statistical matter, treating correlated observations as independent can make uncertainty appear smaller than it is; an appropriate approach depends on the analysis objective and data structure. The registry record does not report the method used for this issue.

What can a confidence interval add?

A point estimate gives a single summary of the observed data, while a confidence interval conveys uncertainty around that estimate under the specified model and assumptions. For a device comparison, the interval would help readers assess whether the estimated association is narrowly or broadly determined by the available observations. The registry record does not provide a primary estimate, confidence interval, or p-value, so no such assessment can be made from the information recorded.

General statistical interpretation also depends on the distinction between statistical evidence and practical measurement performance. A test of whether an association differs from a null value would not establish that the measurements are sufficiently close for a particular operational purpose. Agreement margins or clinically meaningful thresholds would need to be defined and interpreted in context; none are reported in the registry record.

How should planning illustrations be read?

The sample-size assumptions describe a planning illustration based on the observed effect, not the study’s own design. The illustration assumes a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of the observed effect. These are planning assumptions and do not describe the actual single-group observational design, in which participants received monitoring and measurements were compared with standard monitors. Such planning calculations are not observed power and do not provide evidence about the endpoint result. The registry record does not report a sample-size justification for the study itself.

Over-dispersion is a general concern when variability exceeds what a statistical model assumes. If present and unaccounted for, it can affect standard errors and the resulting uncertainty. The record does not report an over-dispersion assessment, a model for the repeated heart-rate observations, or adjustments for participant-level clustering. These omissions do not establish that a particular method was inappropriate; they mean the analysis details needed to evaluate those choices are not reported in the registry record.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("ATLASense RAPHAEL Monitoring")
n   <- c(42)
m   <- c(0.922)
sp  <- c(0.074)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  ATLASense RAPHAEL Monitoring  42  0.922  0.074  0.899  0.945

11. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures and one analysis. The primary endpoint is the heart-rate comparison, while the study description also names data gaps, blood pressure, temperature, alert validation, and logistics. The record does not report a detailed statistical plan identifying which outcomes were confirmatory, how secondary outcomes were analyzed, or whether any multiplicity adjustment was planned. When multiple outcomes or analyses are considered, the chance of finding an apparently notable result by chance can increase; adjustment or a clearly defined hierarchy can help readers interpret that context. Whether either approach was used is not reported in the registry record.

Missing data are especially relevant because the primary population is expressly limited to participants enrolled after the interim analysis who had heart-rate data from standard monitors. The record does not state how many participants were excluded by these criteria, how much minute-by-minute data were absent, or how data gaps were handled in the primary analysis. Data gaps are themselves listed as a secondary outcome, but their results and analysis details are not reported in the registry record.

The registry does not explain the interim analysis, its timing or purpose, or whether it affected data collection or the analysis plan beyond the stated restriction on the primary population. It also does not report additional analysis populations, sensitivity analyses, imputation methods, or assumptions about missingness. These details are important for determining how robust a result may be to incomplete monitoring data, but cannot be inferred from the record.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry’s safety entries list 70 participants at risk for serious adverse events and zero affected, and 70 at risk for other adverse events and zero affected. The deaths entry is also zero. These are the recorded counts for the ATLASense RAPHAEL monitoring group.

These figures should be read as registry-recorded event counts, not as a comprehensive demonstration that monitoring posed no risk. The record does not provide event definitions, collection procedures, follow-up details, or an explanation of how adverse events were attributed. It also does not report a separate comparison group for safety. Because the study is a single-group monitoring comparison, the entries do not support a randomized safety comparison between devices or treatments.

Zero recorded events means that no events are listed in those entries; it does not establish that an event could never occur or that all possible events were captured. The safety counts are distinct from the primary measurement endpoint and do not indicate how closely heart-rate readings from the two monitoring systems agreed.

13. What the Result Does, and Does Not, Mean

The registry record establishes that the study was designed to compare simultaneous intraoperative heart-rate readings from the ATLASense RAPHAEL PolyMonitor and standard intraoperative monitors. It identifies Spearman correlation as the primary endpoint, defines the measurement period as the entire duration of surgery, and limits the primary population to participants enrolled after the interim analysis with standard-monitor heart-rate data. These details clarify the intended measurement question and the scope of the primary analysis.

The numerical primary result is not reported in the registry record. There is no reported correlation estimate, confidence interval, or p-value from which to describe the magnitude or precision of the association. The record also does not report numerical results for the other listed outcomes, including gaps in data collection, mean arterial pressure, or core body temperature. Thus, the study’s stated aims should not be mistaken for demonstrated findings.

Even a reported correlation would answer only whether paired measurements tended to vary together. It would not, by itself, establish that the two devices give sufficiently similar readings in absolute terms, that readings can be substituted without consequence, or that alerts perform accurately. Those questions require result measures and analysis details directed to agreement or alert performance, which are not reported in the registry record.

The study is observational and single-group, with no allocation. It therefore does not provide a randomized comparison of clinical outcomes. Its scope is monitoring measurement and feasibility, not whether a treatment improves health. The safety entries report no recorded serious or other adverse events and no deaths, but their interpretation is limited by the absence of further collection and follow-up details.

In short, the registry describes a relevant paired-monitor comparison and its intended endpoint, but does not report the findings needed to assess measurement association, agreement, missing-data patterns, or operational performance. No conclusion about the device’s performance should be drawn from the endpoint definition or the event counts alone.

14. Why This Trial Matters Statistically

Monitoring comparisons raise a statistical question that is easy to oversimplify: whether two devices are associated is not the same as whether they agree. The study’s use of simultaneous heart-rate readings makes the comparison meaningful as a paired measurement problem, while its Spearman endpoint focuses on association. Recognizing that distinction helps readers avoid treating a correlation coefficient as a direct measure of interchangeability.

The analysis population also matters. The registry restricts the primary endpoint to participants enrolled after the interim analysis who had standard-monitor heart-rate data. That makes clear that the stated target is not simply all enrolled participants. Assessment of data availability, gaps, and repeated observations is central to interpreting intraoperative monitoring comparisons because the amount and pattern of observed data can shape both the estimate and its uncertainty.

The registry describes broader questions about blood pressure, temperature, alerts, and the logistics of use, alongside its primary heart-rate endpoint. These aims illustrate that device evaluation can involve measurement behavior and implementation, not only a single summary statistic. However, the numerical results and methodological details for those aims are not reported in the registry record, so their performance cannot be evaluated from the record.

The main statistical contribution of the study description is therefore its framing: a single-group, observational comparison of device readings against standard monitors during surgery. The record also illustrates why endpoint definitions, analysis populations, missing-data handling, and agreement methods should be explicit. Without numerical estimates and uncertainty, the stated design can be understood, but its measurement findings cannot be judged.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The primary endpoint is defined as a Spearman correlation coefficient, which describes association rather than absolute agreement. The registry record does not report a separate analysis of paired differences, limits of agreement, or another measure that would directly characterize how close the two monitors’ readings were. It also does not report the endpoint estimate or its uncertainty.

The primary analysis population is restricted to participants enrolled after the interim analysis and with heart-rate data available from standard monitors. The registry does not report the number contributing to this analysis, the reason for the post-interim restriction, or the extent and pattern of missing reference-monitor data. Although data gaps are a stated secondary outcome, their results and analytic handling are not reported in the registry record.

The description concerns minute-by-minute measurements over the duration of surgery, which implies repeated observations within participants. The record does not explain how within-participant dependence was handled, how observations were synchronized, or whether the analysis accounted for differences in the amount of data contributed by participants. It does not report device setup, signal-quality criteria, or how discrepant readings were managed.

The registry gives no detailed statistical analysis plan, sample-size justification, or result estimates for the primary or secondary outcomes. It lists a single-group observational model with no allocation, limiting interpretation to measurement comparisons rather than randomized treatment effects. The listed safety counts lack accompanying definitions and collection details. These limitations are specific to what the registry record describes; they do not establish that unreported procedures were not conducted.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Comparison of Intraoperative HR and RR Acquired Via ATLASense Raphael PolyMonitor and Standard Intraoperative Monitors — NCT05291949.
• Registry record last updated 2023-08-16; status last verified 2023-07.
• Results first posted 2023-08-16.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

NCT05291949 is a completed, observational, single-group study sponsored by Henry Ford Health System. The registry lists enrollment of 70, no allocation, and no masking. The study began on 2021-10-18 and has a primary completion date of 2022-01-17.

Participants received ATLASense RAPHAEL PolyMonitor monitoring during surgery. The primary outcome was a Spearman correlation coefficient comparing minute-by-minute heart-rate measurements with standard intraoperative monitors over the entire duration of surgery. The primary population was limited to those enrolled after the interim analysis who had standard-monitor heart-rate data.

The study description also identifies data gaps, blood pressure, body temperature, alerts, and device-use logistics. The registry record does not report numerical results for the primary or secondary outcomes. Safety entries list zero serious adverse events, zero other adverse events, and zero deaths.