(230 days)
The intended use of the CRIT-SCAN II Monitor is as a continuous, non-invasive hematocrit-measuring device whereby a physician could use the information to determine the anemic state of the patient.
The intended use of the CRIT-SCAN II Monitor is as a hematocrit-measuring device.
The CRIT-SCAN II consists of state-of-the-art optoelectronics which, when combined with custom software, has the ability to measure hematocrit transcutaneously (i.e. through a patient's middle finger or index finger). The patient's finger is placed into a custom designed cuff which, when filled with air, creates the necessary perfusion for the optoelectronics to take a hematocrit reading.
Here's an analysis of the provided text regarding the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion | Reported Device Performance |
|---|---|
| Accuracy | 1.5 HCT% compared to Coulter Counter method |
| Correlation Coefficient | 0.972 (comparing CRIT-SCAN II to cell counter data) |
| Standard Deviation | 1.44 (comparing CRIT-SCAN II to cell counter data) |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size (Test Set): 198 patients
- Data Provenance:
- Country of Origin: United States (8 studies) and Sweden (1 study).
- Retrospective or Prospective: The study design indicates a prospective data collection. Data was "gathered" between December 11th, 1997, and September 10th, 1998, with measurements taken non-invasively and blood samples drawn concurrently for comparison.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
The document does not specify the number of experts used to establish ground truth or their qualifications. The ground truth (reference method) was stated as the Coulter Counter method, which is a laboratory instrument, not a human expert.
4. Adjudication Method for the Test Set
The document does not describe an adjudication method for the test set. The comparison was directly between the CRIT-SCAN II readings and the Coulter Counter readings, which serves as the established gold standard.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not conducted. This device is an automated monitor, and the study focused on its accuracy against a laboratory reference, not on human reader performance with or without AI assistance.
6. Standalone (Algorithm Only Without Human-in-the-Loop) Performance
Yes, a standalone performance study was done. The CRIT-SCAN II is described as an automated device that provides a reading in less than 30 seconds. The comparison was solely between the device's output and the Coulter Counter's output, without human interpretation of the CRIT-SCAN II's raw data for diagnosis.
7. Type of Ground Truth Used
The ground truth used was a laboratory reference standard: the Coulter Counter method of hematocrit measurement. This is stated as a "highly accepted method of hematocrit measurement in the blood processing industry."
8. Sample Size for the Training Set
The document does not explicitly state the sample size for a separate training set. The descriptions of data collection appear to refer to the validation or test set. It mentions "IDC gathered data on 198 patients" for the purpose of the study detailed. It is possible that some internal data was used for development prior to this "final" study, but it's not specified here.
9. How the Ground Truth for the Training Set Was Established
Since a distinct training set is not explicitly mentioned, the method for establishing ground truth for development or training would likely be the same as for the test set: comparison to the Coulter Counter method. However, this is an inference as the document focuses on the performance against the predicate.
§ 864.5600 Automated hematocrit instrument.
(a)
Identification. An automated hematocrit instrument is a fully automated or semi-automated device which may or may not be part of a larger system. This device measures the packed red cell volume of a blood sample to distinguish normal from abnormal states, such as anemia and erythrocytosis (an increase in the number of red cells).(b)
Classification. Class II (performance standards).