(76 days)
The HANDMASTER NMS1 is intended to be used to exercise the lower arm and hand by activating the muscles thereof with electrical stimulation. As a powered muscle stimulator, the HANDMASTER NMS1 is intended to be used for the following indications: maintenance or increase of range of motion, reduction of muscle spasm, prevention or retardation of disuse atrophy, muscle reeducation, and increasing local blood circulation.
The HANDMASTER NMS1 is a portable, one-channel electrical neuromuscular stimulator for personal use in exercising the upper extremity. The stimulator serves five surface electrodes held on to the upper limb by a splint. The control unit housing the stimulator may be worn using the shoulder strap provided, or it may be placed on any stable surface. The splint is worn on the hand and forearm. The splint is connected to the control unit by a light cable. A single channel of constant-voltage symmetrical biphasic Russian waveform stimulation is delivered to the muscles through five surface electrodes. Microprocessor-controlled switching of the stimulation between these five electrodes allows the muscles to be activated in combinations either cyclically or continuously. The stimulation is ramped up at the beginning and down at the end of each cycle. The electrode locations allow the HANDMASTER NMS1 to give finger and thumb extension and flexion. The user can select from five stimulation programs by pressing the mode button on the control unit. The stimulation programs are supplied as microprocessor firmware. They comprise either cyclic or continuous activation of the finger and thumb extensors and flexors. The user can increase or decrease the stimulation intensity in ten discrete levels by pressing on buttons labeled "+" or "-" on the control unit. This alters the duration of the stimulation pulse. During the initial system set-up, the clinician opens a clinical panel within the control unit. Adjustments are provided for limiting the maximum current to the extensor muscles and to the flexor muscles, along with a global timing factor which increases or decreases the duration of the stimulation cycles, effectively speeding or slowing the cyclic hand motion. The user starts or stops the stimulation program by pressing a "trigger" button. If required, the user may also stop all stimulation immediately.by switching OFF the device. The HANDMASTER NMS1 splint is used to hold the wrist joint at a comfortable extension angle (20°), and also to hold the electrodes on the forearm and hand segments. It is constructed from fiber-reinforced plastic with soft polyurethane cushion sections to distribute stress over bony regions. The electrodes are made from metal foil coated with carbon-impregnated polymer. Replaceable water-soaked cloth pads are arranged over the electrodes to provide a conductive interface with the skin. A sponge-capped bottle is provided to facilitate wetting of the electrode pads. Rechargeable nickel-cadmium batteries power the device.
The provided document, K982482 for the HANDMASTER NMS1, describes a 510(k) premarket notification for a modified powered muscle stimulator. The purpose of this submission is to demonstrate substantial equivalence to a predicate device, not necessarily to establish new safety and effectiveness criteria through a comprehensive clinical study with acceptance criteria in the typical sense.
Here's an analysis of the provided information relative to your requested structure:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Acceptance Criteria (Implicit from Substantial Equivalence Claim) | Reported Device Performance |
|---|---|---|
| Intended Use | Same as predicate device (K952273) | "The modified HANDMASTER NMS1 and its predicate device have the same intended use, which is to exercise the limb by activating the muscles with electrical stimulation." |
| Indications for Use | Same as predicate device | "The modification to the original HANDMASTER NMS1 will not alter the cleared device's intended use or indications for use." |
| Technological Characteristics | Similar to predicate device, with one specific change (carrier wave frequency) not impacting safety/effectiveness. | The modified device has a higher carrier wave frequency (11,000 Hz) compared to the predicate (5,000 Hz). The submission states, "the stimulation frequency, not the carrier wave frequency, determines the effect and comfort of the stimulation." |
| Safety and Effectiveness | Equivalent to predicate device. The change should not impact safety or effectiveness. | "Importantly, the modification to the HANDMASTER NMS1 could not impact safety or effectiveness because it is well recognized in the medical literature that the stimulation frequency, not the carrier wave frequency, determines the effect and comfort of the stimulation." |
| Performance Data | Oscilloscope Tracing Specification tests completed per Draft FDA Guidance. | "Oscilloscope Tracing Specification tests have been carried out on the modified HANDMASTER NMS1 per Section 1 of the Draft FDA Guidance entitled "Technological Reporting for Powered Muscle Stimulators". This testing measured the stimulator output for the modified HANDMASTER NMS1 at various intensity levels, output loads and operating modes." (Specific quantitative results are not provided in this summary.) |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: This document does not describe a clinical test set with human subjects or a defined "sample size" in the conventional sense for performance evaluation in a clinical study. The performance data mentioned (Oscilloscope Tracing Specification tests) are technical tests performed on the device itself, likely on a limited number of units for engineering verification.
- Data Provenance: Not applicable in the context of a clinical test set. The technical testing was performed on the modified HANDMASTER NMS1 device. The document does not specify the country of origin of the device's manufacture for these specific tests, but the submitter is based in Israel. The data would be considered prospective in relation to the submission, as it was generated to support the 510(k).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- This information is not applicable. The device performance was assessed via technical tests (Oscilloscope Tracing Specification tests), not against a "ground truth" derived from expert clinical assessment. The "ground truth" here is the expected electrical output characteristics described in the FDA guidance and device specifications.
4. Adjudication Method for the Test Set
- This is not applicable as there was no expert-adjudicated clinical test set.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
- No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. The submission is for a powered muscle stimulator, and clinical trials of this nature are generally not required for 510(k) submissions unless substantial equivalence cannot be demonstrated through other means (e.g., technical performance, material safety, and reference to existing literature).
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
- This concept is not directly applicable. The HANDMASTER NMS1 is a physical device that delivers electrical stimulation. Its "performance" refers to its electrical output characteristics. There isn't an "algorithm only" component that would be evaluated in a standalone manner distinct from the physical device's operation. The microprocessor firmware controls the stimulation programs, but its performance is inherently tied to the device's physical output.
7. The Type of Ground Truth Used
- For the technical "Performance Data" mentioned, the "ground truth" or reference standard would be the specifications outlined in Section 1 of the Draft FDA Guidance entitled "Technological Reporting for Powered Muscle Stimulators" and the internal design specifications of the device. This is a technical (engineering) ground truth, not a clinical one (like pathology or expert consensus).
8. The Sample Size for the Training Set
- Not applicable. This is a medical device, not an AI/ML algorithm that is "trained" on a dataset in the typical sense. The microprocessor firmware contains pre-programmed stimulation programs, but these are designed based on established physiological principles and prior device iterations, not a "training set."
9. How the Ground Truth for the Training Set was Established
- Not applicable, as there is no "training set" for this type of device in the context of the provided documentation. The "ground truth" for the device's operational characteristics (e.g., waveform shape, frequency, intensity levels) is based on engineering design, medical literature regarding neuromuscular electrical stimulation, and regulatory guidance for powered muscle stimulators.
§ 890.5850 Powered muscle stimulator.
(a)
Identification. A powered muscle stimulator is an electrically powered device intended for medical purposes that repeatedly contracts muscles by passing electrical currents through electrodes contacting the affected body area.(b)
Classification. Class II (performance standards).