(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.
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Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
October 23, 2015
Firstkind Limited c/o Sheila Hemeon-Heyer President Heyer Regulatory Solutions, LLC 125 Cherry Lane Amherst. MA 01002
Re: K152677
Trade/Device Name: geko™ T-2 Neuromuscular Stimulator Regulation Number: 21 CFR 890.5850 Regulation Name: Powered Muscle Stimulator Regulatory Class: Class II Product Code: IPF Dated: September 18, 2015 Received: September 24, 2015
Dear Ms. Hemeon-Heyer:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food. Drug. and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code 27f Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21
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CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Division of Small Manufacturers, International and Consumer Assistance at its tollfree number (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.
Sincerely yours.
Michael J. Hoffmann -A
for Carlos L. Peña, PhD, MS Director Division of Neurological and Physical Medicine Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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Indications for Use
510(k) Number (if known) K152677
Device Name geko T-2 Neuromuscular Stimulator
Indications for Use (Describe) 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.
Type of Use (Select one or both, as applicable)
| ☑ Prescription Use (Part 21 CER 801 Subpart D) |
|---|
| ☐ Over-The-Counter Use (21 CER 801 Subpart C) |
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510(k) Summarv
This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of 21 CFR 807.92.
rachel.fallon@firstkindmedical.com
| A. Submitter: | Firstkind LimitedHawk HousePeregrine Business ParkHigh Wycombe, UKHP13 7DL |
|---|---|
| Contact:Tel: | Rachel Fallon, Chief Technology Officer+44 (0) 1494 572045 |
- Date Prepared: B. September 18, 2015
Email:
C. Device Name and Classification Information:
| Trade Name: | geko™ T-2 Neuromuscular Stimulator |
|---|---|
| Common/usual Name: | Powered Muscle Stimulator |
| Classification Name: | Stimulator, Muscle, Powered |
| Product Code, CFR: | IPF, 21 CFR 890.5850 |
| Panel code: | 89 |
| Class: | II |
- D. Predicate Device: K133638, geko™ T-1 Neuromuscular Stimulator
ய் Device Description:
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
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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.
F. Indications for Use:
The geko™ T-2 is intended for:
- Increasing local blood circulation, and .
- . Immediate post-surgical stimulation of the calf muscles to prevent venous thrombosis.
G. Contraindications
Powered muscle stimulators should not be used on patients with cardiac demand pacemakers.
Powered muscle stimulators should not be used on patients with recently diagnosed deep vein thrombosis.
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H. Substantial Equivalence
| Parameter | Predicategeko™ T-1 | Proposedgeko™ T-2 |
|---|---|---|
| Intended Use andIndications for Use | Increasing local blood●circulationImmediate post-surgical●stimulation of the calfmuscles to prevent venousthrombosis | Same |
| Clinical application | Prescription use only for use ina clinical or home use setting.Single patient use for up to 30hoursDisposable (cannot be reused) | Same |
| Anatomical Sites | The electrodes are applied tothe posterior aspect of the kneeonly for stimulation of theperoneal nerve. | Same |
| Shelf Life | 24 months | Same |
| Power source | One CR2032 primary lithiumcoin cell. Not replaceable byuser | Same |
| -Method of LineCurrent Isolation | N/A | N/A |
| -Patient LeakageCurrent | ||
| -Normal Condition-Single FaultCondition | < 20μA | Same |
| < 20μA | Same | |
| # output modes | Single mode with sevendiscrete stimulation settingscorresponding to the sevenpulse widths. | Same |
| # output channels | Single channel | Same |
| -Synchronous oralternating | N/A (single channel) | Same |
| -Method of channelisolation | Capacitor | Same |
| Parameter | PredicategekoTM T-1 | ProposedgekoTM T-2 |
| Regulated current orregulated voltage | Current regulated | Same |
| Microprocessorcontrolled? | Yes | Same |
| Automatic overloadtrip | Yes | Same |
| Automatic no-loadtrip | Yes | Same |
| Automatic shut-off | Yes | Same |
| Patient over-ridecontrol | Yes | Same |
| Indicator display | ||
| - On/Off status | Yes | Same |
| - Low battery | Yes (automatic off) | Same |
| -Voltage / currentlevel | N/A (fixed constant current) | Same |
| -Charge level (pulsewidth) | Yes, number of LED flashesindicate stimulation level | Same |
| Timer range inminutes | 1800 minutes maximum(device is disabled after 30hours battery run time) | Same |
| Compliance withvoluntary standards | YesIEC 60601-1:1998 A1, A2IEC 60601-2-10:1987, A1EN 60601-1-2:2007ISO 10993-1 | YesIEC 60601-1:2005, 3rd edIEC 60601-2-10:2012, 2nd edEN 60601-1-2:2007, 3rd edISO 10993-1 |
| Compliance with 21CFR 898 | N/A (electrodes are integralwith the device, there are noseparate leads) | Same |
| Weight | 18 g | 10 g |
| Dimensions | 6" x 1.6" x 0.43" | 7.8" x 1.2" x 0.4" |
| Housing material andconstruction | Plastic injection molding | Same |
| Waveform | Biphasic (asymmetricalbiphasic with zero net DC)Rectangular, with chargebalancing second phase | Same |
| Parameter | Predicategeko™ T-1 | Proposedgeko™ T-2 |
| Maximum outputvoltage | 13.5 V @ 500 Ω54 V @ 2000 Ω110 V @ 10,000 Ω | 14.0 V @ 500 Ω53.5 V @ 2000 Ω255 V @ 10,000 Ω |
| Maximum outputcurrent | 27 mA @ 500 Ω27 mA @2000 Ω11 mA @ 10,000 Ω | 27.9 mA @ 500 Ω26.8 mA @2000 Ω25.5 mA @ 10,000 Ω |
| Pulse width | 70, 100, 140, 200, 280, 400,560 μs | 40, 70, 100, 140, 200, 280,400 μs |
| Frequency | 1 Hz | Same |
| For interferentialmodes only:-beat Frequency (Hz) | N/A | Same |
| Multiphasicwaveforms | ||
| -Symmetrical phases | No | Same |
| -Phase duration | 70-560 µs for positive phase,second (negative) phase is anexponential decay with a 0.1 stime constant | 50-400 µs for positive phase,second (negative) phase isan exponential decay with a0.1 s time constant |
| Net charge | 0 µC at 500 Ω | Same |
| -How achieved | Capacitor coupling | Same |
| Maximum phasecharge | 18.3 µC at 500 Ω | Same |
| Maximum currentdensity | 6.67 mA/cm² | Same |
| Maximum powerdensity | 0.000044 W/cm² | Same |
| Burst mode | N/A (single pulse, no pulsetrain or burst) | Same |
| a) Pulses per burst | ||
| b) Bursts per second | ||
| c) Burst duration(seconds) | ||
| d) Duty Cycle [Line(b) x Line (c)] | ||
| ON Time (seconds) | N/A Stimulation is delivered at1 Hz, with single pulses of70µs to 560µs | N/A Stimulation is deliveredat 1 Hz, with single pulses of50µs to 400µs |
| OFF Time (seconds) | ||
| Parameter | Predicategeko™ T-1 | Proposedgeko™ T-2 |
| Electrodes | Hydrogel applied to silverelectrode. Biocompatibility forthe hydrogel has beenestablished. | Same |
| Cables/ connectors | Integrated device: no separatecables | Same |
| Patient-contact | Contact is made throughintegrated self-adhesiveelectrodes. The geko™ T-1 is asingle channel device. | Same |
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Discussion of differences
The geko™ device has been redesigned for more efficient current delivery, enabling shorter pulse widths at each stimulus level. Replacing the one button design of the geko™ T-1 with a two button design in the geko™ T-2 improves ease of use. The changes resulting in the geko™ T-2 device do not alter the device intended use, indications for use or fundamental scientific technology, and none of the changes significantly affect the safety or effectiveness of the device.
1. Nonclinical Data:
The device changes described in this Special 510(k) were implemented under the company's design change procedures. A risk assessment of the changes resulted in the following verification and validation activities:
Electrical Safety and Electromagnetic Compatibility Testing - The geko™ T-2 has been certified to comply with the applicable clauses of the following standards:
- IEC 60601-1: Medical Electrical Equipment Part 1: General Requirements . for Safety, 3td edition, 2005
- . IEC 60601-2-10: Medical electrical equipment - Part 2-10: Particular requirements for the safety of nerve and muscle stimulators, 2nd edition,
- . IEC 60601-1-2: Medical electrical equipment - Part 1-2: General requirements for basic safety and essential performance - Collateral standard: Electromagnetic compatibility - Requirements and tests, 30 edition, 2007.
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Hardware/Firmware Testing
As with the predicate device, the geko™ T-2 hardware and firmware work together and need to be tested together in order to verify the correct functioning of the device. Testing included the following:
- Verification of output waveform characteristics via oscilloscope output ● tracings at 500Ω, 2kΩ and 10kΩ
- Measurements to compare the geko™ T-2 output currents to those of the ● geko™ T-1 under loads ranging from 500Ω to 10kΩ
- Validation of all geko™ T-2 hardware and firmware functionality
- Usability evaluations by healthy volunteers ●
- Clinical evaluations of the ability to achieve adequate stimulation (calf and . foot twitches) in patients immediately post-operative following elective total hip replacement at a hospital in the United Kingdom
All test results demonstrated that the geko™ T-2 meets the predefined device technical and functional requirements specifications.
I. Conclusions
The information and testing presented in this 510(k) demonstrated that that the geko™ T-2 performs as designed and intended and is substantially equivalent to the predicate device, the geko™ T-1, for increasing local circulation and immediate postsurgical prevention of venous thrombosis.
§ 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).