(374 days)
The N.E.S.S. 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 spasticity, prevention or retardation of disuse atrophy, facilitation and re-education of voluntary motor function, and influencing 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.
The HANDMASTER NMS1 is used for exercising the hand, conditioning selected muscles of the forearm and hand. It is intended for use by patients suffering from upper limb paralysis due to injury or disease of the central nervous system such as cervical spinal cord injuries or stroke.
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 active mode is displayed by a light glowing next to the labeled mode. When the device is stimulating, the light flashes. 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. The intensity is displayed as a number (0 to 9) on a seven-segment display.
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. Battery status can be displayed both during device operation and while recharging the Sources. Both visual and audio battery-low warnings are provided. It is necessary to disconnect splintelectrodes in order to recharge the batteries, as the same socket is used for both.
I am sorry, but the provided text does not contain enough information to complete all sections of your request about acceptance criteria and study details. The text focuses on describing the device's technical characteristics and demonstrating substantial equivalence to predicate devices, rather than detailing a specific clinical performance study with acceptance criteria.
Here's what I can extract and what is missing:
Acceptance Criteria and Device Performance Study Details for N.E.S.S. HANDMASTER NMS1
1. A table of acceptance criteria and the reported device performance
Based on the provided text, the "Performance Data" section describes specification tests rather than clinical performance with defined acceptance criteria related to therapeutic outcomes. The acceptance criteria implied here are that the device's electrical output characteristics meet its design specifications and function as intended.
| Acceptance Criteria Category | Specific Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Electrical Output Parameters | Current Carrier Wave Cycle Duration: Should be 80 µS. | At 10 KΩ resistive load, stimulation carrier wave cycle duration was 80 µS. |
| Stimulation Enable Signal Stop (Zero Intensity): After 100 µS, with a tail to 270 µS. | At zero intensity, stimulation enable signal from microcontroller stopped after 100 µS, resulting in a tail to the pulse from 100 µS to 270 µS where net charge is balanced. | |
| Pulse Progression with Intensity: Lengthening of stimulation enable signal from level 0-5; second full cycle at level 6; five carrier wave cycles at level 9. | At intensity levels 0 to 5, the lengthening of the stimulation enable signal from the microcontroller results in progressively more of the first cycle before it is chopped. At level 6, a second full cycle manifests. By level 9, five carrier wave cycles form the stimulation pulse. | |
| Voltage Output at Various Resistive Loads (e.g., 2 KΩ, 500 Ω): Expected reductions. | Difference between output at 2 KΩ and 10 KΩ was marginal. At 500 Ω, a fall of approximately 30-40% in voltage output was observed. | |
| Voltage Output with Parallel RC Load (2 KΩ and 0.1 µF): Expected reduction. | Reduction of approximately 60% in voltage compared to pure resistive load of 2 KΩ observed. | |
| Open Circuit Voltage Output (Max Intensity): 200 V baseline to peak (Level 9). | Open circuit voltage output (200 V baseline to peak) was measured at intensity level 9 (maximum). | |
| Pulse Frequencies: 36 Hz (Exercise, Exercise-Open); 18 Hz (Open, Grasp, Key modes). | Pulse frequency visualized: 36 Hz in Exercise and Exercise-Open modes, and 18 Hz in Open, Grasp, and Key modes. | |
| Overall Functionality | Device Functions as Intended. | "In all instances, the HANDMASTER NMS 1 functioned as intended." (This is a general statement rather than a specific measurable performance metric from a clinical study, but it's the closest to an overall "acceptance" statement for the technical tests described.) |
2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)
The text describes oscilloscope tracing specification tests conducted on a single device (the "NESS HANDMASTER NMS1 device"). This is a technical verification, not a clinical study involving a test set of patient data. Therefore, this information is not applicable in the typical sense of a clinical trial.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable. The performance data describes technical measurements of the device's electrical output, not a clinical assessment requiring expert-established ground truth.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
Not applicable, as this was a technical specification test, not a clinical study requiring adjudication of findings.
5. 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
Not applicable. The device is a neuromuscular electrical stimulator, not an AI-powered diagnostic tool, and the provided text does not describe an MRMC study.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done
Not applicable. The "Performance Data" section describes functional testing of the device's electrical outputs, not the performance of an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The "ground truth" for the reported performance data consisted of the expected electrical output characteristics of the device as per its design specifications. This is a technical manufacturing/design specification, not a clinical ground truth.
8. The sample size for the training set
Not applicable. The described tests are technical verification of a physical device, not related to an AI model or a training set.
9. How the ground truth for the training set was established
Not applicable. There is no mention of a training set for an AI model.
§ 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).