(147 days)
Serim Blood Leak Test Strips – 2 provide a rapid and convenient means for testing dialysate for occult blood leaks that may occur during the conventional hemodialysis procedure or continuous renal replacement therapy procedures such as continuous arteriovenous hemodialysis or continuous venovenous hemodialysis.
The SERIM Blood Leak Test Strips-2 consist of a 0.2 x 0.2 inch reagent pad attached to one end of a white 0.2 x 3.25 inch polystyrene handle. The reagent pad is immersed into a sample, removed immediately and allowed to react for 60 seconds. Then the reagent pad color is compared to two color blocks on the bottle label. One color block marked Negative is yellow with a few green speckles. If a reagent pad has a similar yellow color the dialysate does not contain significant blood. The second color block is green with small yellow speckles and is marked Positive. A reagent pad with green color equal to or darker than this color block indicates the presence of a significant blood leak.
Here's an analysis of the acceptance criteria and study detailed in the provided document for the SERIM™ Blood Leak Test Strips-2:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Sensitivity: Positive reading for 1.5 mg/dL hemoglobin (corresponding to approximately 0.1 mL/minute blood loss, well below AAMI recommended limit of 0.35 mL/minute or 5.5 mg/dL hemoglobin) | 100% Sensitivity: Sixty positive strip readings were obtained with dialysis buffer containing non-hemolyzed blood at 1.5 mg/dL hemoglobin (as determined by the cyanmethemoglobin method). |
| Specificity: Negative reading for dialysate without significant blood. | 100% Specificity: Sixty negative strip readings were obtained with dialysis buffer without blood. |
| Clear distinction between Positive and Negative color blocks. | Two color blocks on the bottle label (yellow for Negative, green for Positive) provide a clear distinction. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 60 negative samples and 60 positive samples (totaling 120 samples).
- Data Provenance: The document does not specify the country of origin. The data appears to be from a controlled laboratory study, not directly referenced as prospective or retrospective patient data. It describes "blind studies" using "blood standards" in "dialysis buffer."
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
- The document does not specify the number of experts or their qualifications for establishing the ground truth. It states that positive ground truth was defined as "1.5 mg/dL hemoglobin, determined by the cyanmethemoglobin method." This implies reliance on a laboratory assay rather than human expert interpretation for the quantitative ground truth. The color block comparison is manual, but the underlying "true" hemoglobin levels were determined by a standard analytical method.
4. Adjudication Method for the Test Set
- The document does not mention an adjudication method. The test strips are designed for visual comparison to distinct positive and negative color blocks. The 100% sensitivity and specificity reported suggest no ambiguity in interpretation for the tested samples, implying direct comparison to the color blocks was sufficient, without needing further 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 focuses on the standalone performance of the device and its comparison to a predicate device's chemical properties. The document does not discuss human reader performance, either with or without AI assistance.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
- Yes, a standalone performance study was conducted. The "SERIM Blood Leak Test Strips-2" themselves are a standalone diagnostic device. The reported sensitivity and specificity demonstrate the performance of the device independent of human interpretation ambiguity, beyond simply visual classification after the test is run. The device is the "algorithm" in this context (chemical reaction leading to a visual output).
7. Type of Ground Truth Used
- The ground truth for positive samples was established using a quantitative laboratory method: "1.5 mg/dL hemoglobin, determined by the cyanmethemoglobin method."
- The ground truth for negative samples was "dialysis buffer without blood."
8. Sample Size for the Training Set
- The document does not describe a training set or a machine learning algorithm. This device is a chemical test strip, not an AI-based system. Therefore, the concept of a "training set" is not applicable in this context.
9. How the Ground Truth for the Training Set Was Established
- As the device is a chemical test strip and not an AI-based system, there is no "training set," and therefore, no process for establishing its ground truth.
§ 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.