(205 days)
The Mediracer NCS is intended to measure sensory and motor neripheral nerves. The measured data can be utilized in evaluating patients suspected of having focal neuropathies. The measured data must be used in the context of other patient information and must be reviewed and interpreted by a physician.
The Mediracer NCS is a hand-held NCS Device to stimulate and record the nerve responses from patient. The NCS Device is connected to the disposable surface electrodes with cables provided with the NCS Device. The NCS Device communicates via Bluetooth with a computer which is using The Mediracer Analysis Center (MAC) software. The computer uses the MAC software to store and handle the patient measurement data. With the NCS Device comes a charger and a docking station for charging the NCS Device. Also, solution includes a test module for checking the functionality of the whole test system.
The Mediracer NCS is a nerve conduction velocity measurement device. The provided text outlines the performance data for the device, including bench testing and clinical studies, to support its substantial equivalence determination.
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are not explicitly stated as quantitative thresholds in the provided text. Instead, the document focuses on demonstrating substantial equivalence to a predicate device and high agreement with traditional nerve conduction studies. The "performance data" section primarily describes the results of studies rather than pre-defined acceptance criteria with specific numerical targets typical for a 510(k) submission.
However, based on the summary provided, we can infer the reported device performance:
| Performance Metric | Reported Device Performance (Mediracer NCS) |
|---|---|
| Bench Testing - Accuracy | Results "show significantly similar nerve response action potential values" compared to a conventional EMG device, and "matching inside the given deviation." |
| Clinical Study - Positive Agreement | Around 90% (with traditional NCS devices for detecting median nerve lesion in CTS) |
| Clinical Study - Negative Agreement | 99-100% (with traditional NCS devices for detecting median nerve lesion in CTS) |
| Clinical Study - Method Concordance | High concordance between used latency difference parameters between traditional and new device study. |
| Clinical Study - Safety | Non-invasive, safe, no adverse effects or complications reported. |
| Biocompatibility | Hydrogel passed all ISO 10993 testing (Cytotoxicity, Irritation, Sensitization). |
| Electrical Safety & EMC | Complies with IEC 60601-1, IEC 60601-2-40, and EN 60601-1-2. |
| Software Verification & Validation | Software considered "Moderate" level of concern; V&V conducted as per FDA guidance. |
2. Sample Size Used for the Test Set and Data Provenance
The provided text describes two clinical studies used for performance evaluation, which can be considered the test sets.
-
Finnish Multicenter Study:
- Sample Size: 194 patients and 95 healthy control volunteers.
- Data Provenance: Finland (multicenter study).
- Retrospective or Prospective: The description strongly suggests a prospective study ("recruited patients," "went through a clinical examination, Mediracer NCS measurement and the traditional NCS").
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United Kingdom Study:
- Sample Size: 63 patients (selected from 104 referrals).
- Data Provenance: United Kingdom (Leicester Carpal Tunnel Service).
- Retrospective or Prospective: Description indicates patients "were recruited from the normal referral stream," "fulfilled the clinical CTS diagnosis after symptom inquiry and clinical assessment," and "went through clinical assessment, Mediracer NCS measurement and the traditional NCS," suggesting a prospective study.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The text states that in both clinical studies, participants underwent "traditional nerve conduction studies (NCS)" and "clinical assessment." The "traditional NCS" likely serves as the ground truth. It also mentions that "The data measured is reviewed and interpreted by a specially trained physician or specialist in neurophysiology."
- Number of Experts: Not explicitly stated how many distinct experts were involved in interpreting the traditional NCS for ground truth establishment within the context of the studies. It refers to "a specially trained physician or specialist in neurophysiology" in general terms for interpreting Mediracer NCS data, but does not specify for the ground truth of the studies.
- Qualifications of Experts: Assumed to be "specially trained physician or specialist in neurophysiology," as they are the ones who perform and interpret traditional NCS. Specific experience levels (e.g., "10 years of experience") are not provided.
4. Adjudication Method for the Test Set
The adjudication method for determining the true disease status based on the "traditional NCS" is not explicitly described. It only states that the traditional NCS was performed. It doesn't mention if multiple readers reviewed the traditional NCS, or if there was a consensus process (e.g., 2+1, 3+1).
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, and the effect size of how much human readers improve with AI vs without AI assistance
- MRMC Comparative Effectiveness Study: No, an MRMC comparative effectiveness study involving human readers with vs. without AI assistance was not done. The study compares the Mediracer NCS device (which is also used by humans) against traditional NCS devices, not the effect of AI on human reader performance. The Mediracer NCS itself is a measurement device, and while it has accompanying software (MAC), the study is evaluating the device's diagnostic capability, not an AI's interpretative assistance to a clinician.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) was done
- Standalone Performance: No, a standalone (algorithm only) performance study was not done in the context of an AI algorithm. The Mediracer NCS is a device that requires a human operator ("used by physician or by technician on the order of physician") to take measurements, and a physician to review and interpret the data. The "Mediracer Analysis Center (MAC) software" is for storing and handling data, not an AI for autonomous interpretation or diagnosis.
7. The Type of Ground Truth Used
The ground truth used in the clinical studies was based on traditional nerve conduction studies (NCS) and clinical assessment for diagnosing Carpal Tunnel Syndrome (CTS). This would fall under expert consensus/clinical diagnosis derived from established diagnostic procedures.
8. The Sample Size for the Training Set
The document does not mention a training set for the Mediracer NCS device. This is likely because the Mediracer NCS is presented as a measurement device, not an AI/machine learning algorithm that requires a training phase. Its equivalence is established through direct comparison to existing measurement techniques and devices.
9. How the Ground Truth for the Training Set Was Established
Since no training set is mentioned for an AI/machine learning model, the method for establishing its ground truth is not applicable here.
§ 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).