(91 days)
The NeuroMetrix NC-stat is intended to measure neuromuscular signals that are useful in diagnosing and evaluating systemic and entrapment neuropathies.
The NC-stat consists of the following four components:
- A handheld, battery-powered monitor. The monitor contains the electronic circuitry and software required to provide initiate and control the nerve conduction study, acquire and save patient and test information, display information on the LCD readout, and transmit data to the docking station. LCD displays include the distal motor latency (DML) value, the F-wave latency value, limb indicator (left or right), low battery indicator, the memory slot being used to store the test data, and user messages (menu selections, sensor serial numbers, device status, operator instructions, and error conditions).
- A docking station used to download the test data to the onCall Information Management Service via an analog phone line.
- Single-use, disposable biosensors for the median, ulnar, tibial, and peroneal nerves. The tibial and peroneal biosensors are the only new accessories for the NC-stat.
- The onCall Information Management Service for generation of the hardcopy patient test report, which includes test results (distal motor latency, F-wave latency, and associated waveforms) and a comparison of patient results to reference ranges. Reports are sent to the user by facsimile.
The provided 510(k) Summary for NC-stat does not contain specific acceptance criteria or an explicit study description with detailed performance metrics. The document focuses on demonstrating substantial equivalence to predicate devices for the 510(k) submission.
However, based on the information provided, we can infer some aspects relevant to device performance and study design:
1. Table of Acceptance Criteria and Reported Device Performance:
The document states: "Clinical data submitted in the 510(k) demonstrates that nerve conduction measurements obtained using the NC-stat are comparable to those obtained using conventional nerve conduction measurement equipment."
This implies that the acceptance criteria for the NC-stat's performance were based on its ability to produce measurements (Distal Motor Latency, F-wave latency, and associated waveforms) that are comparable or substantially equivalent to existing, legally marketed nerve conduction velocity measurement devices.
Without specific numerical thresholds or statistical metrics, a direct table of acceptance criteria and reported device performance cannot be created from this document. The "comparable" statement serves as the general performance claim.
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size: The document does not specify the sample size used for the clinical data.
- Data Provenance: The document does not explicitly state the country of origin or whether the data was retrospective or prospective. It only mentions "Clinical data submitted in the 510(k)."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications:
The document does not provide any information about the number of experts, their qualifications, or how ground truth was established for the test set. It describes the device's output (DML, F-wave latency, waveforms) but not the process of ground truth validation. Since the comparison is to "conventional nerve conduction measurement equipment," it's likely that the ground truth would be measurements obtained from such established equipment, potentially interpreted by trained medical professionals (e.g., neurologists or clinical neurophysiologists) as standard practice.
4. Adjudication Method for the Test Set:
The document does not mention any adjudication method for the test set.
5. Multi-Reader, Multi-Case (MRMC) Comparative Effectiveness Study:
A MRMC comparative effectiveness study is not mentioned. The focus is on the device's ability to produce comparable measurements to conventional equipment, not on how human readers improve with AI assistance.
6. Standalone Performance Study (Algorithm Only):
The device itself is a measurement tool, not an AI algorithm in the contemporary sense. Its performance is inherently "standalone" in that it directly measures neuromuscular signals and calculates parameters. The comparison is between the NC-stat's measurements and those from conventional equipment. The document implies that the device's accuracy in these measurements was evaluated to show "comparability."
7. Type of Ground Truth Used:
The ground truth implicitly used for comparison would be measurements obtained from conventional nerve conduction measurement equipment. This would be considered a form of expert consensus/established clinical practice or a reference standard rather than pathology or outcomes data in this context. The "comparable measurements" statement suggests that a gold standard for nerve conduction measurements already exists.
8. Sample Size for the Training Set:
The document does not mention any specific training set or its sample size. This is consistent with the device design, which appears to be a direct measurement system rather than a machine learning model that requires a discrete training phase. The device relies on established biophysical principles for nerve conduction measurement.
9. How the Ground Truth for the Training Set Was Established:
As there is no mention of a training set for a machine learning model, this information is not applicable and therefore not provided in the document.
§ 882.1550 Nerve conduction velocity measurement device.
(a)
Identification. A nerve conduction velocity measurement device is a device which measures nerve conduction time by applying a stimulus, usually to a patient's peripheral nerve. This device includes the stimulator and the electronic processing equipment for measuring and displaying the nerve conduction time.(b)
Classification. Class II (performance standards).