(35 days)
The geko™ T-2 Neuromuscular Stimulator is intended for:
-Increasing local blood circulation; and
-Immediate post-surgical stimulation of the calf muscles to prevent venous thrombosis.
The geko™ T-2 Neuromuscular Stimulator (geko™ T-2) is a disposable, fully integrated unit composed of a constant current pulse generator with embedded software and battery enclosed in an over-molded plastic casing, and a silver electrode with a hydrogel coating which provides a means of attachment of the device and electrical contact with the patient. Two buttons are used to control the On/Off function and increase or decrease the intensity level of the device output, which is achieved through changes in the delivered pulse width. The geko™ T-2 is applied so that the electrodes lie over the common peroneal nerve behind the knee. Stimulation of the common peroneal nerve causes contraction of the calf muscles through the direct activation of the motor neurons, resulting in increased blood flow.
The stimulus intensity varies with the pulse width, which can be set to one of seven levels for the geko™ T-2. The asymmetric biphasic waveform results in a net charge of zero to the patient during each pulse cycle. The pulse rate is fixed at a frequency of 1 Hz and is used to isometrically stimulate the leg and foot muscles with a cadence and energy similar to that of walking.
Electrical contact is made with the patient through a hydrogel layer applied during manufacture to the integrated electrode. The patient contacting materials have been previously tested per the requirements of ISO 10993-1 and shown to be biocompatible for prolonged (up to 30 days) contact with intact skin. There are no separate electrode leads or electrodes.
Here's an analysis of the provided text to fulfill your request regarding acceptance criteria and study information for the geko™ T-2 Neuromuscular Stimulator.
Important Note: The provided document is a 510(k) summary, which focuses on demonstrating substantial equivalence to a predicate device rather than presenting a full clinical trial report with detailed acceptance criteria and standalone performance metrics. Therefore, some requested information, particularly regarding specific numerical acceptance criteria (e.g., sensitivity, specificity, AUC) and a multi-reader multi-case (MRMC) comparative effectiveness study, is not explicitly stated in this type of regulatory submission. The assessment here is based on the information available within the given text.
Acceptance Criteria and Device Performance for geko™ T-2 Neuromuscular Stimulator
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Requirement | Reported Device Performance (geko™ T-2) |
|---|---|---|
| Electrical Safety | Compliance with IEC 60601-1 (3rd ed, 2005) | Certified to comply. |
| Compliance with IEC 60601-2-10 (2nd ed, 2012) | Certified to comply. | |
| Electromagnetic Compatibility (EMC) | Compliance with IEC 60601-1-2 (3rd ed, 2007) | Certified to comply. |
| Biocompatibility | Compliance with ISO 10993-1 (for prolonged contact with intact skin up to 30 days) | Patient contacting materials previously tested per ISO 10993-1 and shown to be biocompatible. |
| Output Waveform Characteristics Verification | Correct waveform output at 500Ω, 2kΩ, 10kΩ loads (via oscilloscope tracings) | Verification confirmed correct waveform characteristics. |
| Output Current Comparison | Output currents comparable to predicate device (geko™ T-1) under loads from 500Ω to 10kΩ | Measurements confirmed comparable output currents. (Specific numeric range for "comparable" is not explicit, but the conclusion is that it meets requirements for substantial equivalence.) |
| Hardware and Firmware Functionality | Validation of all geko™ T-2 hardware and firmware functionality | Validation confirmed all functionality. |
| Usability | Usability evaluation by healthy volunteers | Evaluations performed. (Specific metrics or "pass" criteria not detailed, but overall conclusion is meeting requirements.) |
| Clinical Efficacy (Stimulation) | Ability to achieve adequate stimulation (calf and foot twitches) in target patient population | Clinical evaluations confirmed ability to achieve adequate stimulation in patients immediately post-operative following elective total hip replacement. (The term "adequate" implies meeting a predefined clinical threshold, though the specific definition is not here.) |
| Substantial Equivalence | Device performs as designed and intended and is substantially equivalent to the predicate device | Information and testing demonstrated that the geko™ T-2 performs as designed and intended and is substantially equivalent to the geko™ T-1 for increasing local circulation and immediate postsurgical prevention of venous thrombosis. This is the overarching "acceptance criterion" for a 510(k) submission. |
| Intended Use and Indications for Use | Same as Predicate: Increasing local blood circulation; Immediate post-surgical stimulation of calf muscles to prevent venous thrombosis | Same as predicate (geko™ T-1). |
| Other Device Parameters | Clinical application, anatomical sites, shelf life, power source, insulation, leakage current, output modes/channels, regulated current, microprocessor control, safety trips, patient override, indicator display, timer range, compliance with standards (as listed in table). | All listed parameters are "Same" as the predicate device, or meet the updated standards (e.g., IEC 60601-1:2005, 3rd ed). Specific performance for Maximum output voltage, Maximum output current, Pulse width, and Phase duration are provided for comparison, showing minor differences but within acceptable limits to maintain substantial equivalence. The overall conclusion is that these differences do not significantly affect safety or effectiveness. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size:
- Usability Evaluations: "healthy volunteers" - Not specified numerically.
- Clinical Evaluations (Efficacy): "patients immediately post-operative following elective total hip replacement" - Not specified numerically. This sounds like a small pilot or verification study rather than a large-scale clinical trial given the context of a 510(k) summary.
- Data Provenance:
- Usability Evaluations: Not specified.
- Clinical Evaluations (Efficacy): "at a hospital in the United Kingdom" - Prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
- Not Applicable / Not Explicitly Stated. The verification and validation activities described are largely engineering and performance testing (comparing outputs, waveforms) and basic clinical assessment of "adequate stimulation" (calf and foot twitches). There is no indication of a "ground truth" adjudicated by multiple experts in the sense you might expect in an AI diagnostic study. The "ground truth" for the clinical evaluation would simply be the observed presence of calf and foot twitches.
4. Adjudication Method for the Test Set
- Not Applicable / Not Explicitly Stated. Since the evaluation methods are primarily focused on
- Compliance with standards (pass/fail for certificates).
- Physical measurements (waveform, current).
- Observation of a physiological response (twitches).
There is no indication of a need for a multi-expert adjudication method like 2+1 or 3+1.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size of AI vs. Without AI Assistance
- No, an MRMC comparative effectiveness study was not done. This device is a neuromuscular stimulator, not an AI-powered diagnostic imaging tool. The comparison is between the new geko™ T-2 and its predicate, the geko™ T-1, focusing on physical and electrical characteristics and basic clinical capability. There is no AI component involved in the "assistance" to human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Not Applicable. This is a hardware device with embedded software controlling its stimulation functionality. Its "performance" is inherent in its electrical output and the resulting physiological response, not in an independent algorithmic "reading" or classification that could be considered "standalone."
7. The Type of Ground Truth Used
- For Biocompatibility: Compliance with ISO 10993-1, likely through laboratory testing and material analysis.
- For Electrical Safety/EMC: Compliance with IEC 60601-1, IEC 60601-2-10, IEC 60601-1-2 standards, validated by accredited testing bodies.
- For Hardware/Firmware: Measured electrical characteristics (e.g., output current, waveform patterns), internal functional tests.
- For Clinical Efficacy (Stimulation): Direct observation of physiological response (calf and foot twitches) in patients.
8. The Sample Size for the Training Set
- Not Applicable / Not Explicitly Stated. This device does not use machine learning that requires a "training set" in the conventional sense of AI models (e.g., for image recognition or predictive analytics). The embedded software controls the device's electrical output based on fixed parameters and user input, not on learned patterns from a dataset.
9. How the Ground Truth for the Training Set Was Established
- Not Applicable. As there is no "training set" for an AI algorithm in this context, there is no ground truth established for it. The device's operation is based on established electrophysiology and engineering principles.
§ 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).