Search Results

Indications for EMS use are:

• Prevention or retardation of muscle disuse atrophy
• Relaxation of muscle spasms
• Increasing local blood circulation
• Muscle re-education
• Immediate post-surgical stimulation of calf muscles to prevent venous thrombosis
• Maintaining or improving range of motion of extremities

Indications for TENS use are:

• Symptomatic relief and management of chronic, intractable pain, and
• Adjunctive treatment for post-surgical and post-trauma acute pain

SWISSSTIM is a battery-powered device for transcutaneous nerve and neuromuscular electro-stimulation. It has two channels (outputs) of stimulation, each with independent intensity control. The unit delivers synchronous, low voltage stimulation impulses at both of its outputs. The stimulation output voltage waveforms are in form of trains of monophasic, rectangular impulses. Such waveform character is true, when the outputs are connected to any resistor in a range from 100 Ω to 10,000 Ω.

The EMS mode of this device has four different stimulation programs. The medical professional or patient under medical supervision can select any of these four stimulation programs, as appropriate for their treatment objectives. For each stimulation program, the medical professional or patient selects the desired phases of the stimulation programs as well as the stimulation duration; the impulse frequencies and impulse durations are different and all are preset at the factory.

There are no user accessible controls that can change either the frequency or impulse duration during a treatment. The user accessible controls are the ON/OFF button, the SELECT button and the two (2) buttons that control menu access and intensity levels for the 2 independent channels. The stimulus is a low voltage, low frequency, rectangular waveform.

The TENS mode of this device has ten (10) programs. The TENS mode is what has been added to this device and therefore modifies the Indications for Use from the predicate device, K022175. The TENS mode is controlled in the same fashion as the EMS mode of the SWISSSTIM.

The device is housed in a plastic enclosure and is powered by four (4) AAA batteries. Accessories include output cables, batteries, User's Manual, storage case and electrodes. There is no provision for an AC adapter and the unit cannot be connected to any AC electrical power circuit.

From a technical perspective, the SWISSSTIM delivers stimulation pulses of 50v (peak value) ± 10% onto 500Ω at maximum settings, which corresponds to 100 mA (peak value) current intensity. The impulse frequencies produced by the device are in a range of 1 Hz to 120 Hz, depending on the choice of stimulation program. The voltage waveforms are rectangular monophasic with duration time from 20 us to 1000 us. The current impulses are monophasic on 500 Ω load. The tetanization stimulation signal includes ramp, which slowly increases the contraction intensity during treatments.

The EMS function is used as a therapeutic tool, specifically for rehabilitation purposes as noted in the Indications for Use (please see Section B). An example is prevention of disuse muscle atrophy that may occur after musculoskeletal injuries such as damage to bones, joints, muscles, ligaments and tendons. The TENS functions address pain mitigation, whether chronic or acute pain; TENS is a non-invasive, safe nerve stimulation intended to reduce such pain. A number of systematic reviews or meta-analyses have confirmed TENS effectiveness for postoperative pain, osteoarthritis, and chronic musculoskeletal pain.

The provided text describes the SWISSSTIM device, a battery-powered transcutaneous nerve and neuromuscular electro-stimulation device. The document is a 510(k) summary, which focuses on demonstrating substantial equivalence to predicate devices rather than independent performance validation studies with human subjects. Therefore, much of the requested information regarding sample sizes, expert ground truth, adjudication methods, and MRMC studies is not typically found in such a submission.

Here's a breakdown of the available information:

1. Table of Acceptance Criteria & Reported Device Performance:

The document outlines performance characteristics of the SWISSSTIM and compares them to predicate devices (P4-PHYSIO and Styline 882). The acceptance criteria are implicit in showing similar technical characteristics and safety profiles to the legally marketed predicate devices.

Study Proving Acceptance Criteria:

The study that proves the device meets the acceptance criteria is primarily a non-clinical performance and substantial equivalence comparison study against two predicate devices: P4-PHYSIO (K022175) and Styline 882 (K092448).

• Non-Clinical Performance Data: The document states, "The SWISSsm device (and predicate devices) have also been analyzed in accordance with the AAMI/ANSI standard 'AAMI NS4:1986/(R)2009: AAMI Standard for Transcutaneous Electrical Nerve Stimulators' Electrode/Skin Impedance Model (ESIM)". This involved electrical performance testing, likely using bench testing methods and an ESIM to simulate skin impedance.
• Substantial Equivalence Argument: The core of the submission relies on demonstrating that the SWISSSTIM has similar technological characteristics (design, materials, energy source, waveforms, programs), indications for use, safety features, and operational parameters as the legally marketed predicate devices. Visual comparisons of voltage and current waveforms across different load resistances (500 ohms, 2000 ohms, 10000 ohms, and ESIM) are provided to support this. The detailed comparison table further highlights similar safety and efficacy aspects.
• Compliance with Standards: The device's manufacturing quality (ISO 9001/2000, ISO 13485/2003) and electrical safety (IEC-601-2-10 European Safety Standard and all EC medical device directives) were tested and reported to be compliant. Electromagnetic Compatibility (EMC) and Electrical Safety tests were conducted according to FDA recommended testing with "Pass" results for all listed standards (EN 55011, EN 61000-4-2, EN 61000-4-3, EN 61000-4-6, EN 61000-4-8).

Details not explicitly stated in the document:

2. Sample size used for the test set and the data provenance: This is a 510(k) submission primarily relying on non-clinical bench testing and comparison to predicates. There isn't a "test set" in the context of clinical data or human subjects. The graphical data (waveforms) would represent measurements from the physical devices under various load conditions. The data provenance would be the test labs where these electrical measurements were performed, likely in Switzerland (Valmed's location). This is not specified as retrospective or prospective in a clinical sense.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable. Ground truth for electrical performance is established by measurement instruments calibrated to standards.
4. Adjudication method for the test set: Not applicable for non-clinical bench testing.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done: No. This type of study is typically for diagnostic imaging devices involving human readers.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done: The device is a physical electro-stimulator, not an algorithm. Its standalone performance is demonstrated through the electrical and safety tests.
7. The type of ground truth used: For the non-clinical performance evaluation, the "ground truth" is derived from physical measurements against established electrical engineering standards and the specified performance of the predicate devices. For safety and efficacy, the ground truth is based on compliance with international standards (ISO, IEC, EC MDD) and a demonstration of substantial equivalence to already cleared devices with known safety and efficacy profiles.
8. The sample size for the training set: Not applicable. This is not a machine learning device that requires a training set.
9. How the ground truth for the training set was established: Not applicable.

Ask a specific question about this device