(61 days)
This TDS Standard Solution is indicated for verifying the accuracy (calibration) of TDS (Total Dissolved Solids) meters. This standard solution should be used immediately before conductivity meters are used to determine the conductivity of water obtained from water purification systems used in hemodialysis. This solution is prepared from a mixture of salts comprised of 40% Sodium Bicarbonate, 40% Sodium Sufate, and 20% Sodium Chloride which is intended to mimic natural water systems. These solutions are used remotely from the water purification equipment, and do not come into contact with the patient.
The device consists of salts (Sodium Chloride, Sodium Bicarbonate and Sodium Sulfate) dissolved in de-ionized water. The solution is packaged into sealed polyethylene bottles.
The document describes the acceptance criteria and supporting studies for the "TDS Standard Solution."
Here's the breakdown of the requested information:
1. Table of acceptance criteria and the reported device performance
| Test | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Conductivity Values (25ºC) - New Device | 23.8 ± 0.2 microsiemen/cm; 229 ± 2 microsiemen/cm; 2060 ± 0.02 microsiemen/cm | The new device's TDS values (15ppm, 150ppm, 1500ppm) were found to be within the tolerances of the solution and the Reference Conductivity meter. |
- 15ppm TDS Solution: 15.063 ppm, 15.032 ppm, 15.007 ppm, 14.988 ppm, 14.994 ppm.
- 150ppm TDS Solution: 150.546 ppm, 150.480 ppm, 150.546 ppm, 150.876 ppm, 150.744 ppm.
- 1500ppm TDS Solution: 1508.18 ppm, 1505.99 ppm, 1505.99 ppm, 1506.72 ppm, 14.994 ppm. |
| Open Bottle Shelf Life | Remained within specification for 60 days after the bottle was opened and tightly recapped. | The three values (23.8 µS/cm, 229 µS/cm, and 2060 µS/cm) were all found to be within tolerance after the bottle was opened for 60 days and then tightly resealed. |
| Sealed Bottle Storage Shelf Life | Remained within specification for 18 months after the bottle was sealed. | The results for 23.8 µS/cm, 229 µS/cm, and 2060 µS/cm solutions showed that they remained in tolerance for 18 months. Multiple batches were tested, demonstrating uniform properties throughout production. The goal to produce solutions with values within the lower 10% range of specifications was met to ensure values remained within specification after 18 months. |
2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample Size for performance tests (Conductivity Values): 5 bottles were tested for each TDS solution (15ppm, 150ppm, 1500ppm).
- Sample Size for Open Bottle Shelf Life: The number of bottles tested is not explicitly stated, but it refers to "the new device" in general terms for the three specified conductivity values, suggesting at least one for each value.
- Sample Size for Sealed Bottle Storage Shelf Life: For each of the three conductivity values (23.8 µS/cm, 229 µS/cm, and 2060 µS/cm), five different batches were manufactured. For each batch, 5 bottles were measured at specified intervals over 18 months.
- Data Provenance: The document does not specify the country of origin of the data. The studies appear to be prospective, as they involve manufacturing and then testing the new device over time for shelf life and immediate performance.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
- The ground truth for the test set (conductivity values) was established using a Reference Conductivity meter calibrated with Standard Reference Materials purchased from Cole-Palmer. The document does not mention the use of human experts to establish ground truth or their qualifications. The ground truth is based on the calibrated instrumentation and reference materials.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Adjudication methods like 2+1 or 3+1 are typically used in studies involving human interpretation or subjective assessment. This device's performance testing is objective (measurement of conductivity), and thus no adjudication method was used or needed. The results were directly measured by a calibrated instrument.
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 MRMC comparative effectiveness study was done. This device is a standard solution for calibrating meters, not an AI-powered diagnostic tool. Therefore, the concept of human readers improving with AI assistance is not applicable here.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Yes, a standalone performance assessment was done. The performance of the "TDS Standard Solution" (the device itself) was evaluated by measuring its conductivity properties directly using a calibrated Reference Conductivity meter. This assessment did not involve a human-in-the-loop for the primary measurement of the solution's properties.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- The ground truth used was based on objective measurement against Standard Reference Materials using a calibrated Reference Conductivity meter. This is a form of instrumental ground truth, rather than expert consensus, pathology, or outcomes data, which are typically found in diagnostic applications.
8. The sample size for the training set
- This device is a physical standard solution, not a machine learning model. Therefore, there is no training set in the context of algorithm development.
9. How the ground truth for the training set was established
- Since there is no training set for an algorithm, this question is not applicable.
§ 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.