(597 days)
The LiquoGuard CSF system is indicated for the external drainage of cerebrospinal fluid (CSF). It connects to any drainage catheter (not part of the product) which is usually inserted by the doctor into the lateral or third ventricle of the brain or lumbar subarachnoid space in selected patients to reduce intracranial pressure. The LiquoGuard CSF system controls CSF pressure using pressure sensors and a pump, thus taking the role of the conventional CSF dripping chamber and collection bag (predicate devices). The LiquoGuard CSF system also monitors intracranial pressure up to 75 mmHg and cerebrospinal fluid flow during CSF drainage, and provides many alarm functions not offered by the passive dripping chamber systems.
The LiquoGuard CSF System consists of a pump and a corresponding tube set with pressure sensors. The dynamic range of this system is from -15mmHg to +75 mmHg. The tube set is inserted into the pump, connected to the intrathecal drainage catheter (not part of the product) via Luer-Lock and the LiquoGuard CSF System device via cable connector. The device then continuously measures the pressure inside the tube and operates a tube pump whenever the actual pressure is higher than a preselected target pressure. Thus the LiquoGuard CSF System combines CSF drainage and intracranial pressure (ICP) monitoring with integrated alarm and documentation/data logging functions, improving safety, simplifying the handling and enhancing patient mobility (by its battery back-up).
Acceptance Criteria and Device Performance for LiquoGuard CSF System (K121248)
The provided document describes the Moller Medical LiquoGuard CSF System, which is indicated for external drainage and monitoring of cerebrospinal fluid (CSF). The acceptance criteria for this device are established through a combination of bench tests and a comparative clinical study against predicate devices.
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are implicitly defined by the successful completion of the bench tests and the demonstration of equivalence in adverse event rates during the clinical study. No specific numerical thresholds for acceptance were explicitly stated beyond "all tests passed according to the predetermined pass/fail criteria."
| Acceptance Criteria Category | Specific Test/Criterion | Reported Device Performance |
|---|---|---|
| Pressure Measurement | Absence of sensor drift during packaging / sterilization | Passed |
| Absence of sensor drift during ageing | Passed | |
| Precision of displayed pressure at various pump rates and pressure loads | Passed | |
| Pressure Regulation | Endurance test with in-vitro simulated patient | Passed |
| Performance comparison with drip chamber | Passed | |
| Reliability of pump shut-off with negative pressures | Passed | |
| Device functions independent of positioning | Passed | |
| Volume and Flow Measurement | Precision of total volume and flow (pump rate) measurement | Passed |
| Alarm Functions (Patient Condition) | Pressure alarms | Passed |
| Pulsation alarm (e.g., catheter occlusion, collapsed ventricles, disconnected catheter) | Passed | |
| Pressure too constant alarm (e.g., catheter occlusion, collapsed ventricles, disconnected catheter) | Passed | |
| Influence of pressure on catheter walls | Passed | |
| Detection of clogged catheter | Passed | |
| Alarm Functions (Device Functions) | Defective/disconnected sensors | Passed |
| Disconnected/leaking tube set | Passed | |
| Battery low | Passed | |
| Main controller/watchdog cross-check | Passed | |
| Double safety | Passed | |
| Tube set too old | Passed | |
| Battery defective | Passed | |
| Mechanical Handling and Operation | Disposable check for single-use | Passed |
| Wrong tube set insertion | Passed | |
| Opening of front panel | Passed | |
| Disposable check for age | Passed | |
| Endurance | Automatic switch to battery upon power failure | Passed |
| Tube set durability | Passed | |
| Other | External connectivity | Passed |
| Clinical Equivalence (Adverse Events) | Total rates of incidence of adverse events compared to predicate devices | "Very close, with most small variations in favor of the LiquoGuard." Supports equivalence. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size (Clinical Study): 413 patient records.
- Data Provenance: The records were collected from "several hospitals," indicating a multi-center study. The clinical study combines "similar, independent studies," suggesting a retrospective collection and aggregation of existing patient data rather than a new prospective study exclusively for this submission. The country of origin of the data is not explicitly stated in the provided text.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
The document does not specify the number or qualifications of experts used to establish ground truth for the clinical study. The clinical study compares "adverse events" between the LiquoGuard and predicate devices, implying that these events were recorded as part of standard clinical practice.
4. Adjudication Method for the Test Set
The document does not specify an adjudication method (e.g., 2+1, 3+1, none) for the clinical study's adverse event data. It mentions identifying and comparing rates of incidence, which suggests a quantitative analysis of pre-recorded data rather than a consensus-based adjudication process for individual cases.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not conducted. The study focused on comparing adverse event rates between the device and predicate devices in a clinical setting, not on assessing human reader performance with or without AI assistance.
6. Standalone (Algorithm Only) Performance
The device is not an AI-driven diagnostic algorithm. It is a medical device that combines hardware (pump, sensors) and software for CSF drainage and monitoring. Therefore, a standalone (algorithm only) performance study as typically understood for AI/CAD devices was not performed. Its performance is assessed through the comprehensive bench tests and clinical comparison.
7. Type of Ground Truth Used for the Test Set
The ground truth for the "test set" (clinical study) was based on clinical outcomes data, specifically "adverse events" recorded in patient records resulting from CSF drainage using either the LiquoGuard or predicate drip chambers.
8. Sample Size for the Training Set
The document does not explicitly mention a "training set" as would be typical for machine learning models. The device's development and validation relied on engineering principles, bench testing, and a clinical comparison to existing devices. Therefore, a specific sample size for a "training set" in the context of an AI/ML model is not applicable from the provided information.
9. How the Ground Truth for the Training Set Was Established
As there is no explicit mention of a training set in the context of machine learning, the question of how its ground truth was established is not directly applicable. The device's functionality is based on established fluid dynamics, pressure sensing, and pump control mechanisms. Its design and performance would have been refined through iterative engineering development and testing against specifications derived from medical requirements and predicate device functions.
§ 882.5550 Central nervous system fluid shunt and components.
(a)
Identification. A central nervous system fluid shunt is a device or combination of devices used to divert fluid from the brain or other part of the central nervous system to an internal delivery site or an external receptacle for the purpose of relieving elevated intracranial pressure or fluid volume (e.g., due to hydrocephalus). Components of a central nervous system shunt include catheters, valved catheters, valves, connectors, and other accessory components intended to facilitate use of the shunt or evaluation of a patient with a shunt.(b)
Classification. Class II (performance standards).