(413 days)
The intended use of the CRIT-LINE III TQA Monitor is as a non-invasive hematocrit, oxygen saturation, and percent change in blood volume monitor. The CRIT-LINE III TQA Monitor also non-invasively estimates access recirculation and non-invasively estimates access blood flow. In addition, the CLM III TQA Monitor calculates an estimated Urea Reduction Ratio based on relative changes in urea nitrogen concentration in the spent dialysate.
The CRIT-LINE III TQA is an FDA cleared device that non-invasively measures Hct, O2 Sat, Percent Change in Blood Volume. The CLM III TOA also estimates Access Recirculation and Access Blood Flow. The URR sensor is an additional attachment to the CRIT-LINE III TOA. The optical light emitted by the URR sensor is directed through the spent dialysate stream and absorbed by the constituents of the spent dialysate. The transmitted light is then detected and the relative urea nitrogen concentration in the spent dialysate is calculated.
The CRIT-LINE III TQA Monitor is intended to non-invasively calculate the Urea Reduction Ratio (URR) based on changes in urea nitrogen concentration in spent dialysate. The device was compared to the EktaChem DT 60 (Vitros DT60 Chemistry System), a legally marketed predicate device.
Here's an analysis of the acceptance criteria and study information:
1. Acceptance Criteria and Reported Device Performance
The submission does not explicitly state pre-defined acceptance criteria in terms of specific statistical thresholds for R-squared or standard error for the overall URR calculation. Instead, it presents the results of the comparative studies with the predicate device as evidence of substantial equivalence.
| Performance Metric | Acceptance Criteria (Implied by Predicate Performance) | Reported Device Performance (CLM III TQA URR Sensor) |
|---|---|---|
| In-vivo Relative Urea Nitrogen Concentration (mg/dL) | Not explicitly stated but compared to EktaChem DT 60 as predicate | Standard error of 5.8 mg/dL and R² of 0.84 |
| In-vitro Urea Nitrogen Concentration (mg/dL) | Not explicitly stated but compared to EktaChem DT 60 as predicate | Standard error of 1.2 mg/dL and R² of 0.998 (range 0-83 mg/dL) |
2. Sample Size and Data Provenance
Test Set:
- Sample Size:
- In-vivo study: 51 data points for URR calculation. This was gathered from 36 patients.
- In-vitro study: Not explicitly stated as a number of samples, but "measurements at each urea nitrogen concentration" were performed across a range of 0-83 mg/dL.
- Data Provenance: Not explicitly stated (e.g., country of origin, specific clinical sites). The date range of data collection (January 1 to May 10, 2001) is provided, indicating it was prospective data collection for the in-vivo study.
3. Number of Experts and Qualifications for Ground Truth
In-vivo study: Not applicable. The ground truth for the in-vivo study was established by the EktaChem DT 60, a laboratory analyzer.
In-vitro study: Not applicable. The ground truth for the in-vitro study was established by the Kodak EktaChem DT 60 analyzer using known concentrations of pure urea.
4. Adjudication Method for the Test Set
Not applicable. The ground truth was established by laboratory analysis (EktaChem DT 60) for both in-vivo and in-vitro studies, not by human expert adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. The study focused on comparing the device's measurements to a predicate laboratory device.
6. Standalone Performance (Algorithm Only)
Yes, a standalone performance assessment was done. The study directly compared the CRIT-LINE III TQA URR sensor's measurements against the EktaChem DT 60 without human intervention for the URR calculation claim.
- In-vivo: The CLM III TQA's calculated URR based on relative urea nitrogen concentration in spent dialysate was compared to URR measurements calculated by the EktaChem DT 60 (based on urea nitrogen concentration measurements in both blood and spent dialysate).
- In-vitro: The URR sensor measurements were compared against reference urea nitrogen concentrations measured by the Kodak EktaChem DT 60 analyzer using calibrated solutions.
7. Type of Ground Truth Used
The ground truth used was predicate device measurements / laboratory analysis:
- In-vivo: The EktaChem DT 60's calculation of URR, which itself is based on urea nitrogen concentration measurements in both blood and spent dialysate.
- In-vitro: Reference urea nitrogen concentrations measured by a Kodak EktaChem DT 60 analyzer with pure urea dissolved in fresh dialysate.
8. Sample Size for the Training Set
The document does not explicitly mention a separate "training set" or its sample size. The description focuses on the studies conducted to demonstrate substantial equivalence, which would be considered the validation data.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as no separate training set is described. The predicate device's measurements served as the reference for the validation studies.
§ 876.5820 Hemodialysis system and accessories.
(a)
Identification. A hemodialysis system and accessories is a device that is used as an artificial kidney system for the treatment of patients with renal failure or toxemic conditions and that consists of an extracorporeal blood system, a conventional dialyzer, a dialysate delivery system, and accessories. Blood from a patient flows through the tubing of the extracorporeal blood system and accessories to the blood compartment of the dialyzer, then returns through further tubing of the extracorporeal blood system to the patient. The dialyzer has two compartments that are separated by a semipermeable membrane. While the blood is in the blood compartment, undesirable substances in the blood pass through the semipermeable membrane into the dialysate in the dialysate compartment. The dialysate delivery system controls and monitors the dialysate circulating through the dialysate compartment of the dialyzer.(1) The extracorporeal blood system and accessories consists of tubing, pumps, pressure monitors, air foam or bubble detectors, and alarms to keep blood moving safely from the blood access device and accessories for hemodialysis (§ 876.5540) to the blood compartment of the dialyzer and back to the patient.
(2) The conventional dialyzer allows a transfer of water and solutes between the blood and the dialysate through the semipermeable membrane. The semipermeable membrane of the conventional dialyzer has a sufficiently low permeability to water that an ultrafiltration controller is not required to prevent excessive loss of water from the patient's blood. This conventional dialyzer does not include hemodialyzers with the disposable inserts (Kiil type) (§ 876.5830) or dialyzers of high permeability (§ 876.5860).
(3) The dialysate delivery system consists of mechanisms that monitor and control the temperature, conductivity, flow rate, and pressure of the dialysate and circulates dialysate through the dialysate compartment of the dialyzer. The dialysate delivery system includes the dialysate concentrate for hemodialysis (liquid or powder) and alarms to indicate abnormal dialysate conditions. This dialysate delivery system does not include the sorbent regenerated dialysate delivery system for hemodialysis (§ 876.5600), the dialysate delivery system of the peritoneal dialysis system and accessories (§ 876.5630), or the controlled dialysate delivery system of the high permeability hemodialysis system § 876.5860).
(4) Remote accessories to the hemodialysis system include the unpowered dialysis chair without a scale, the powered dialysis chair without a scale, the dialyzer holder set, dialysis tie gun and ties, and hemodialysis start/stop tray.
(b)
Classification. (1) Class II (performance standards) for hemodialysis systems and all accessories directly associated with the extracorporeal blood system and the dialysate delivery system.(2) Class I for other accessories of the hemodialysis system remote from the extracorporeal blood system and the dialysate delivery system, such as the unpowered dialysis chair, hemodialysis start/stop tray, dialyzer holder set, and dialysis tie gun and ties. The devices subject to this paragraph (b)(2) are exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 876.9.