(67 days)
The NeuroMotion WalkAide is intended to address the lack of ankle dorsiflexion in patients who have sustained damage to upper motor neurons or pathways to the spinal cord. During the swing phase of gait, the WalkAide electrically stimulates the appropriate muscles that cause ankle dorsiflexion and may thus improve the patient's gait. Medical benefits of Functional Electrical Stimulation (FES) may include prevention/retardation of disuse atrophy, increased local blood flow, muscle re-education, and maintained or increased joint range of motion.
The WalkAide is an external functional electrical stimulator. It is a small device that attaches to the leg just below the knee, near the head of the fibula. During a gait cycle, the WalkAide stimulates the common peroneal nerve, which innervates the tibialis anterior and other muscles that cause dorsiflexion of the ankle.
Here's a breakdown of the acceptance criteria and study information for the NeuroMotion WalkAide, based on the provided text:
Acceptance Criteria and Reported Device Performance
The submission does not explicitly state formal "acceptance criteria" in terms of specific performance thresholds for clinical or technical metrics for the WalkAide itself. Instead, it focuses on demonstrating substantial equivalence to predicate devices by comparing technical specifications and functional characteristics.
The table below summarizes the comparison to predicate devices, which implicitly serves as the "acceptance criteria" through equivalence:
| Feature | Acceptance Criteria (Predicate Devices) | Reported Device Performance (WalkAide) |
|---|---|---|
| Stimulation Type | External Functional Neuromuscular Stimulator (Implied by predicates) | External Functional Electrical Stimulator |
| Constant Current Range | 0 - 100mA (Respond III/Select), 0 - 50mA (Verite Model 817) | 0 - 95mA |
| Pulse Duration (μsec.) | 300 (Respond III/Select), 500 (+ve: EMPI), 110 (Verite Model 817) | 200 |
| Frequency Range (PPS) | 1 - 80 (Respond III/Select), 20 - 50 (EMPI), 50 (Verite Model 817) | 25 |
| Electrode Size & Shape | Various, including 2.5cm diameter (Respond III/Select), 3cm & 5cm diameter (EMPI), 4.3cm diameter (Verite Model 817) | 2.5cm diameter, Round |
| Stimulation Activation | Foot sensor (capable, for predicates and WalkAide) | Foot sensor (capable), Built-in tilt sensor |
| General Safety | No new issues regarding safety (Implied by predicates) | Claims no new safety issues |
| General Effectiveness | No new issues regarding effectiveness (Implied by predicates) | Claims no new effectiveness issues |
Study Information
The provided 510(k) summary describes a series of tests rather than a single, comprehensive clinical study. The primary goal of these tests was to establish substantial equivalence to predicate devices, not to prove standalone efficacy against specific clinical endpoints with a large patient cohort.
-
Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective):
The document does not detail specific sample sizes for users or patients in the "testing" section. The tests listed are technical in nature, focusing on device characteristics. There's no indication of patient data provenance (country of origin, retrospective/prospective). It appears to be device-centric testing rather than patient-centric clinical trials. -
Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience):
This information is not provided in the document. The tests described are technical device evaluations, not those requiring expert interpretation of clinical data against a ground truth. -
Adjudication method (e.g. 2+1, 3+1, none) for the test set:
This information is not provided. Given the nature of the tests (e.g., "Stimulation Pulse Characteristics," "Electrode Current Density Spread"), formal clinical adjudication methods like 2+1 or 3+1 would not apply. -
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:
No MRMC comparative effectiveness study was done. The WalkAide is an external functional electrical stimulator, not an AI-powered diagnostic or assistive tool for human interpretation. Therefore, the concept of "human readers improve with AI" is not applicable here. -
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
The document describes standalone device testing in terms of its technical characteristics, such as pulse parameters, electrode performance, and trigger mechanisms. The "Clinician System Application Program" also suggests testing of the device's software interface for clinicians. However, this is not an "algorithm only" in the modern AI sense, but rather the device functioning as intended in a controlled environment. -
The type of ground truth used (expert consensus, pathology, outcomes data, etc):
For the technical tests mentioned (Stimulation Pulse Characteristics, Electrode Current Density Spread, Foot Sensor Characteristics, Stimulation Trigger Source Timing, Clinician System Application Program), the "ground truth" would be established by engineering specifications, direct measurements using calibrated equipment, and functional verification against design requirements. It is not clinical ground truth like pathology or outcomes data. -
The sample size for the training set:
This information is not applicable/not provided. The WalkAide, as described, is a functional electrical stimulator and does not appear to employ machine learning or AI models that would require a "training set" in the context of diagnostic or predictive algorithms. -
How the ground truth for the training set was established:
This information is not applicable/not provided for the same reason as point 7.
§ 882.5810 External functional neuromuscular stimulator.
(a)
Identification. An external functional neuromuscular stimulator is an electrical stimulator that uses external electrodes for stimulating muscles in the leg and ankle of partially paralyzed patients (e.g., after stroke) to provide flexion of the foot and thus improve the patient's gait.(b)
Classification. Class II (performance standards).