(139 days)
The NxStage Dosing Calculator is intended to provide chronic hemodialysis prescription options with the NxStage System One and Cartridge with pre-attached dialyzer based on patient and treatment parameters. With a specified set of algorithms, it automatically performs calculations that are typically done by a physician or licensed healthcare practitioner. The algorithms used have been established and documented in scientific literature.
The NxStage Dosing Calculator is a software modeling program designed to assist physicians and licensed healthcare practitioners in prescribing chronic hemodialysis therapy with the NxStage System One and NxStage Cartridge with pre-attached dialyzer. It allows physicians and licensed healthcare practitioners to determine a range of appropriate treatment frequencies, treatment durations, and therapy fluid volumes. The program incorporates formulas that have been published in peer reviewed journals of medicine and models treatment parameters for a range of possible treatment frequencies, volumes, and durations. This is a tool only and does not replace the need for the physician or licensed healthcare practitioner to make an independent determination of the therapy best suited for the patient.
The provided text describes a software device called the "NxStage Dosing Calculator" but offers limited details about specific acceptance criteria or a detailed study proving its performance. The information focuses more on the regulatory submission process and the device's intended use and technological characteristics rather than a rigorous performance evaluation with quantitative metrics.
Here's an analysis based on the available text:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Software readiness | Met |
| Software design review | Met |
| Usability | Met |
| Adequately designed for labeled indications for use | Documented as such through performance, verification, and validation testing. |
| Substantially equivalent to predicate device | Documented as such through performance, verification, and validation testing. |
| Suitable for the labeled indications for use | Documented as such through performance, verification, and validation testing. |
Study Details
The text indicates that "Performance, verification and validation testing was conducted to characterize performance of the proposed device. This included testing for software readiness, software design review, and usability." However, it does not provide specific details about the methodology, sample sizes, or results of these tests beyond stating that "All predetermined acceptance criteria were met."
Therefore, many requested details cannot be extracted from the provided document.
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample Size for Test Set: Not specified.
- Data Provenance: Not specified. It's likely that a "test set" in the traditional sense of clinical data might not have been used, as this is a Dosing Calculator (software) which performs calculations based on established algorithms. The testing likely focused on the accuracy of these calculations and the software's functionality and usability, rather than real-world patient outcomes.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Not specified. Given the nature of a dosing calculator based on published algorithms, the "ground truth" would likely be derived from the mathematical accuracy of the implemented formulas rather than expert consensus on individual cases.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not specified.
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
- Not applicable. This is a dosing calculator, not an AI for image interpretation or diagnosis requiring human reader comparison. The device is designed to assist physicians in calculations, not to be compared against human diagnostic performance or to augment human interpretation.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
- Yes, implicitly. The device itself is a standalone software that performs calculations. The testing mentioned ("software readiness, software design review, and usability") would inherently evaluate the algorithm's performance and the software's functionality without human intervention in the calculation process. Its output (prescription options) is then used by a human healthcare practitioner.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- The "ground truth" for a dosing calculator is primarily the accuracy and correctness of the mathematical algorithms implemented, as established and documented in scientific literature. The device "automatically performs calculations that are typically done by a physician or licensed healthcare practitioner" using "algorithms that have been published in peer reviewed journals of medicine." Therefore, adherence to these established algorithms and correct computational output would constitute the ground truth.
8. The sample size for the training set
- Not applicable. This device is a rule-based system based on established algorithms, not a machine learning model that requires a "training set" in the typical sense.
9. How the ground truth for the training set was established
- Not applicable, as it is not a machine learning model requiring a training set. The algorithms themselves are the "ground truth" derived from scientific literature.
§ 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.