(28 days)
The CRIT-LINE MONITOR III, (CLM III) is a non-invasive hematocrit, oxygen saturation and percent change in blood volume monitor used in the treatment of hemodialysis patients. In addition, the CLM III estimates access recirculation and access blood flow in hemodialysis patients.
The CLM III consists of a state-of-the-art microprocessor which has all of the chip select logic, serial communication, timing and watchdog circuits incorporated within it. The CLM III is used in conjunction with the In-Line Diagnostics Blood Chamber. The blood chamber is connected to and becomes part of the dialysis tubing circuit. The sensor from the CLM III is connected to the blood chamber which reads critical blood parameters as blood passes through the blood chamber.
Here's an analysis of the provided text regarding the CRIT-LINE MONITOR III, structured to answer your questions:
Acceptance Criteria and Device Performance Study for CRIT-LINE MONITOR III
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Stated Goal) | Device Performance (Reported Result) |
|---|---|
| Correlation coefficient value near 1 (i.e., .90 or greater) for internally calculated ABF vs. externally calculated ABF. | Correlation coefficient: 0.94 |
| - | Average difference between methods: 46 ml/min |
| - | Standard deviation of difference: 200 ml/min |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 29 data points
- Data Provenance: Retrospective (though collected specifically for this validation, it's not a prospective interventional trial based on the description).
- 16 data points from Victoria Hospital in London Ontario, Canada (April 8th and April 9th, 1999)
- 13 data points from Central Valley Dialysis in Salt Lake City, Utah (June 22nd and June 24th, 1999)
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not mention the use of experts to establish ground truth. The "ground truth" (or reference method) was established by calculating Access Blood Flow (ABF) values externally using CRIT-LINE MONITOR III hematocrit measurements fed into a formula via a calculator or spreadsheet program (which was the previously approved method, K982412).
4. Adjudication Method for the Test Set
No adjudication method is described. The comparison was statistical between two calculated values (one internally by the device, one externally using device-generated hematocrit data and a formula).
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done, If So, What was the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance
No, an MRMC comparative effectiveness study was not done. This device is a monitor measuring physiological parameters; it's not an AI system for image interpretation or diagnosis that would typically involve human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
Yes, in a way. The study's purpose was to validate the internal calculation of ABF by the CRIT-LINE MONITOR III. This internal calculation is essentially the "algorithm only" performance, compared against the established external calculation method which uses data generated by the same device (CLM III hematocrit measurements) but processes it outside the device. The study is evaluating the device's self-contained ABF calculation capability.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
The "ground truth" was the previously approved method of ABF measurement, which involved:
- Measuring hematocrit values using the CLM III.
- Calculating ABF values externally via a calculator or spreadsheet program using these measured hematocrit values.
- This method itself had a 510(k) clearance (K982412).
Essentially, the ground truth was a reference calculation method using device-generated data.
8. The Sample Size for the Training Set
The document does not mention a separate training set. The CRIT-LINE MONITOR III is a physical device with a software modification for internal calculation. The description implies the software was developed based on existing understanding of the ABF formula and then validated with the 29 data points as the "test set" against the established external calculation method. It's unlikely that machine learning or a training set in the modern sense was used for this type of device in 1999.
9. How the Ground Truth for the Training Set Was Established
As no explicit training set is mentioned, this question is not applicable. The device's internal ABF calculation functionality was evaluated against a pre-existing, legally marketed method of calculating ABF.
§ 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.