(256 days)
The Edwards Algorithm for Measurement of Blood Hemoglobin is indicated for continuously monitoring changes to hemoglobin concentration in the circulating blood of adults ≥ 40 kg receiving advanced hemodynamic monitoring using HemoSphere ForeSight Oximeter Cable and non-invasive ForeSight sensors (large) in cerebral locations.
The Edwards Algorithm for Measurement of Blood Hemoglobin is intended for use as an adjunct monitor of relative and total hemoglobin concentration of blood in individuals at risk for reduced-flow or no-flow ischemic states in surgical and ICU settings.
The Edwards Algorithm for Measurement of Blood Hemoglobin is intended for continuously and non-invasively monitoring the relative and total hemoglobin values in the blood of patients requiring advanced hemodynamic monitoring in a critical care environment. The outputs of the algorithm include the relative changes in total hemoglobin in blood ( $\Delta$ tHb) and total hemoglobin in blood (tHb) parameters and are derived from the relative change in concentration of total tissue hemoglobin ( $\Delta$ ctHb parameter) measured by the ForeSight Oximeter Cable on the HemoSphere Advanced Monitoring Platform (K213682, cleared June 22, 2022).
The subject algorithm provides relative blood hemoglobin ( $\Delta$ tHb; measured in g/dL of blood) values continuously as a change over time from 0 g/dL. It can also be calibrated using an optional input of reference blood hemoglobin measurements such as ones obtained in vitro from a blood gas analyzer. When calibrated, it provides the value of total blood hemoglobin (tHb).
Additionally, the algorithm also provides three secondary output flags:
o DoNotCalibrate Flag: This flag is intended to indicate when a calibration should not be performed.
o Recalibrate Flag: This flag is intended to indicate when a new calibration is recommended.
o Unstable Flag: This flag is intended to indicate when the input signal ( $\Delta$ ctHb) is unstable.
The provided text describes the Edwards Algorithm for Measurement of Blood Hemoglobin, an algorithm intended for continuously monitoring changes to hemoglobin concentration. Here's a breakdown of the acceptance criteria and the study proving its performance:
1. Table of Acceptance Criteria and Reported Device Performance
| Parameter | Acceptance Criteria (Target) | Reported Device Performance |
|---|---|---|
| Accuracy (Bias) | Bias close to 0 g/dL | Bias close to 0 g/dL |
| Precision (Standard Deviation) | Precision less than 1 g/dL | Precision less than 1 g/dL |
| Overall Error (RMSE/ARMS) | 1 g/dL | Met 1 g/dL |
Note: The document states "The results demonstrated that the subject device subject device met the acceptance criteria of 1g/dL with a bias close to 0 and precision less than 1g/dL". While it mentions meeting the criteria, the exact numerical values for bias and precision are not explicitly provided in the text beyond "close to 0" and "less than 1g/dL". The 1g/dL criteria appears to be for RMSE/ARMS.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 83 patients
- Data Provenance:
- Country of Origin: Data was collected from 5 sites across the US and EU.
- Amsterdam, The Netherlands (European Union) - 27 patients (32.53%)
- Santander, Spain (European Union) - 8 patients (9.64%)
- Greenville, North Carolina, USA - 18 patients (21.69%)
- Sacramento, California, USA - 11 patients (13.25%)
- Chicago, Illinois, USA - 19 patients (22.89%)
- Retrospective or Prospective: Retrospective analyses were performed on data already collected, independent of the device development.
- Country of Origin: Data was collected from 5 sites across the US and EU.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
The document does not explicitly state the number of experts used or their specific qualifications for establishing the ground truth. However, it indicates that the device's performance was compared against a "laboratory co-oximeter," which implies a gold standard measurement method rather than expert consensus on images.
4. Adjudication Method for the Test Set
Not applicable. The ground truth was established by laboratory co-oximeter measurements, not through expert adjudication of human interpretations.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC comparative effectiveness study was not done. The study focused on the algorithm's direct performance against a laboratory co-oximeter. The text states, "No clinical trial was performed in support of the subject 510(k) submission."
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
Yes, a standalone performance study was done. The performance data was assessed by comparing the device's output to laboratory co-oximeter measurements, without human interaction with the algorithm's output during the measurement process. The algorithm's outputs are numerical values for hemoglobin concentration.
7. The Type of Ground Truth Used
The ground truth used was laboratory co-oximeter measurements of total hemoglobin values in blood. This is considered a highly accurate and objective reference method for hemoglobin quantification.
8. The Sample Size for the Training Set
The document does not provide information regarding the sample size used for the training set. The descriptions provided are solely for the retrospective analysis performed for validation (the test set).
9. How the Ground Truth for the Training Set was Established
The document does not provide information regarding how the ground truth for the training set was established, as details about the training phase are not included in the provided text.
§ 870.2700 Oximeter.
(a)
Identification. An oximeter is a device used to transmit radiation at a known wavelength(s) through blood and to measure the blood oxygen saturation based on the amount of reflected or scattered radiation. It may be used alone or in conjunction with a fiberoptic oximeter catheter.(b)
Classification. Class II (performance standards).