The geko™ W-2 neuromuscular stimulator is a disposable, fully integrated unit composed of a constant current pulse generator with embedded software, a lithium coin-cell 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 choosing one of 10 stimulus settings. The geko™ W-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 pulse rate is fixed at a frequency of 1 Hz and is used to isometrically stimulate the calf and foot muscles with a cadence and energy similar to that of walking. Each geko™ W-2 provides two 6-hour treatments with a 6 hour minimum rest period between treatments. Two optional accessories are available to hold the geko W-2 in place during treatment, if needed: a knee strap and an adhesive tape.

AI/ML Overview

The geko™ W-2 device is a neuromuscular stimulator intended for increasing local blood circulation and edema reduction. The following information outlines its acceptance criteria and the study conducted to demonstrate equivalence to a predicate device.

1. Table of Acceptance Criteria and Reported Device Performance

The FDA 510(k) summary focuses on demonstrating substantial equivalence to a predicate device (geko™ Plus R-2, K180082) rather than defining specific numerical acceptance criteria for clinical performance. Instead, acceptance is based on the device meeting established performance standards for safety and fundamental operational characteristics, and showing that any differences from the predicate do not raise new questions of safety or effectiveness.

Parameter	Acceptance Criteria (Demonstrated)	Reported Device Performance (geko™ W-2)
Biocompatibility	Device materials in contact with intact skin must be biocompatible according to ISO 10993-5 (Cytotoxicity) and ISO 10993-10 (Sensitization and Irritation). The new hydrogel (KM40A) must meet these standards.	KM40A hydrogel demonstrated biocompatibility for intended use contact.
Electrical Safety	Must comply with relevant electrical safety standards. (Implied: No changes from predicate, hence predicate compliance assumed to cover the geko™ W-2).	Not tested, as there are no changes in electrical hardware compared to the predicate (geko™ Plus R-2).
Electromagnetic Compatibility (EMC)	Must comply with IEC 60601-1-2:2014. This includes requirements for a non-rechargeable, battery-powered medical device regarding electromagnetic disturbances.	All tests were passed based on IEC 60601-1-2:2014, with testing conducted in continuous operating mode at the highest stimulus setting.
Hardware/Firmware Functionality	The device's hardware and firmware must function correctly, including accurate output waveform characteristics across various loads and overall device functionality.	All tests were passed, verifying output waveform characteristics via oscilloscope tracings (at 500Ω, 2kΩ, and 10kΩ) and validating all geko™ W-2 hardware and firmware functionality.
Performance (Durability/Adhesion)	Device durability must be maintained over multiple uses, including resistance to application/removal cycles and adequate adhesion for intended use.	All test samples passed all repeat test cases for: 1) device operation when applied and removed from a test substrate 100 times; and 2) device adhesion when applied and removed for a total of 10 use cycles.
Indications for Use Consistency	The device's indications for use must be a subset of or equivalent to the predicate device, or any differences must be justified and not raise new safety or effectiveness concerns. Specifically, for increasing local blood circulation and edema reduction. Must not be indicated for prevention of venous thrombosis due to shorter treatment duration.	The indications for use (increasing local blood circulation and edema reduction) are a subset of the predicate, as the geko™ W-2 is not indicated for venous thrombosis prevention due to its limited 6-hour treatment duration. Otherwise, the indications are consistent.
Technical Specifications (Comparison to Predicate)	Any differences in technical specifications (e.g., number of stimulus levels, treatment duration, hydrogel type) must be adequately explained and supported, and not compromise safety or effectiveness.	The geko™ W-2 has 10 stimulus levels (vs. 8 in predicate, with two lower pulse widths added), two 6-hour treatments with a 6-hour rest (vs. single 30-hour run time), and uses KM40A hydrogel (vs. KM10T). These changes are justified for patient comfort/sensitivity.

2. Sample Size and Data Provenance for Test Set, and Training Set Sample Size

The document primarily describes design validation activities rather than a study with a traditional "test set" for clinical performance. The focus is on engineering verification and validation.

Test Set Sample Size: Not explicitly stated as a separate clinical test set. The validation activities involve discrete hardware, software, and material tests. For example, durability testing involved multiple (100 and 10) application/removal cycles on test samples. Biocompatibility testing typically involves a set number of samples for in vitro and in vivo assessments as per ISO standards but is not quantified in this summary.
Data Provenance (Test Set): Data is generated through internal laboratory testing and external accredited lab testing (e.g., for biocompatibility and EMC) conducted as part of the device's design validation. The country of origin for these tests is not specified, but the submitter is Firstkind Limited in the UK.
Sample Size for Training Set: This device is a hardware neuromuscular stimulator, not an AI/ML-based algorithm. Therefore, there is no "training set" in the context of machine learning.

3. Number of Experts and Qualifications for Ground Truth Establishment (Test Set)

This is not applicable to the information provided. The ground truth for the engineering tests is based on established scientific principles, medical device standards (e.g., ISO, IEC), and the functional specifications of the device. Expert clinicians are not typically involved in establishing "ground truth" for electrical safety or biocompatibility tests.

4. Adjudication Method (Test Set)

Not applicable. The validation activities are based on meeting pre-defined objective criteria in engineering and material performance tests, not on expert adjudication of subjective outcomes.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

Not applicable. This device is an electrical stimulator, not an imaging or diagnostic AI device. There is no AI component that assists human readers.

6. Standalone (Algorithm Only) Performance Study

Not applicable. This device is a physical neuromuscular stimulator. It is not an algorithm that operates in a standalone manner.

7. Type of Ground Truth Used (for Test Set)

The "ground truth" for the validation activities are:

Objective Engineering Standards: Compliance with ISO (biocompatibility), IEC (EMC), and internal validated specifications for electrical characteristics (waveform, current, voltage, pulse widths, frequency), software functionality, and mechanical durability.
Predicate Device Specifications: The predicate device's established safe and effective technical parameters serve as a baseline for demonstrating substantial equivalence for the core functional aspects.

8. Sample Size for Training Set

As mentioned in point 2, this is not an AI/ML device, so there is no "training set."

9. How Ground Truth for Training Set was Established

Not applicable, as there is no training set.

Summary

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Image /page/0/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, with the letters "FDA" in a blue square. To the right of the blue square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.

January 18, 2020

Firstkind Limited % Sheila Hemeon-Heyer President Heyer Regulatory Solutions LLC 125 Cherry Lane Amherst, MA 01002

Re: K193045

Trade/Device Name: geko™ W-2 Regulation Number: 21 CFR 890.5850 Regulation Name: Powered Muscle Stimulator Regulatory Class: Class II Product Code: IPF Dated: December 19, 2019 Received: December 19, 2019

Dear Sheila 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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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 of 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

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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 CFR Part 807); labeling (21 CFR Part 801 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

For Vivek Pinto, Ph.D. Director DHT5B: Division of Neuromodulation and Physical Medicine Devices OHT5: Office of Neurological and Physical Medicine Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K193045

Device Name geko™ W-2

Indications for Use (Describe)

Increasing local blood circulation
Edema reduction

Type of Use (Select one or both, as applicable)

X Prescription Use (Part 21 CFR 801 Subpart D)

| Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) Summary - K193045

This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of 21 CFR 807.92.

A. Submitter:	Firstkind LimitedHawk HousePeregrine Business ParkHigh Wycombe, UKHP13 7DL
Contact:	Neil BuckleyHead of Quality and Regulatory Affairs
Tel:Email:	+44 (0) 845 2222 921neil.buckley@firstkindmedical.com

B. Date Prepared: November 1, 2019

C. Device Name and Classification Information:

Trade Name:	geko™ W-2
Common Name:	Neuromuscular stimulator
Classification Name:	Stimulator, Muscle, Powered
Product Code, CFR:	IPF, 21 CFR 890.5850
Panel code:	89
Class:	II

Predicate Devices: qeko™ Plus R-2 as cleared under K180082 D.

Device Description: E.

The geko™ W-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 pulse rate is fixed at a frequency of 1 Hz and is used to isometrically stimulate the calf and foot muscles with a cadence and energy similar to that of walking. Each geko™

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W-2 provides two 6-hour treatments with a 6 hour minimum rest period between treatments. Two optional accessories are available to hold the geko W-2 in place during treatment, if needed: a knee strap and an adhesive tape.

F. Indications for Use:

Increasing local blood circulation .
Edema reduction ●

G. Technical Comparison with the Predicate Device and Discussion of Differences

Parameter	ProposedgekoTM W-2	PredicategekoTM Plus R-2 (K180082)
Indications for use	Increasing local blood circulation• Edema reduction	Increasing local blood circulation• Edema reduction• Immediate post-surgical stimulation of calf muscles to prevent venous thrombosis
# output modes	1	1
# output channels- Synchronous oralternating?- Method of channelisolation?	1N/AN/A	1N/AN/A
Method of stimulusregulation	Current regulated	Current regulated
Microprocessorcontrolled?	Yes	Yes
Automatic overloadtrip	Yes	Yes
Automatic no-loadtrip	Yes	Yes
Automatic shut-off	Yes	Yes
Patient over-ridecontrol	Yes	Yes
Parameter	ProposedgekoTM W-2	PredicategekoTM Plus R-2 (K180082)
Indicator displays
- On/Off status	Yes	Yes
- Low battery	Yes	Yes
- Stimulus level	Yes (device switches off)	Yes (device switches off)
	Yes. Stimulation level (pulsewidth) is indicated by the numberof times the LED flashes insequence, e.g., a single flash forLevel 1 (25 $\mu$ s/54 mA) up to 10flashes for Level 10 (560 $\mu$ s/54mA).	Yes. Stimulation level (pulsewidth) is indicated by the numberof times the LED flashes insequence, e.g., a single flash forLevel 1 (50 $\mu$ s/54 mA) up to 8flashes for Level 8 (560 $\mu$ s/54mA).
Waveform	Asymmetrical, biphasic,rectangular waveform with chargebalancing second phase	Asymmetrical, biphasic,rectangular waveform with chargebalancing second phase
Maximum outputvoltage	27.0 V @ 500 Ω	27.0 V @ 500 Ω
	108 V @ 2000 Ω	108 V @ 2000 Ω
	255 V @ 10,000 Ω	255 V @ 10,000 Ω
	All voltages (±10%)	All voltages (±10%)
Maximum outputcurrent	54 mA @ 500 Ω	54 mA @ 500 Ω
	54 mA @ 2000 Ω	54 mA @ 2000 Ω
	25.5 mA @ 10,000 Ω	25.5 mA @ 10,000 Ω
	All currents (±15%)	All currents (±15%)
Pulse widths	25, 35, 50, 70, 100, 140, 200,280, 400, 560 $\mu$ s	50, 70, 100, 140, 200, 280, 400and 560 $\mu$ s
Frequency	1 Hz, fixed	1 Hz, fixed
Net charge	0 $\mu$ C at 500Ω, capacitor coupled	0 $\mu$ C at 500Ω, capacitor coupled
Maximum phasecharge	40 $\mu$ C at 500 Ω	40 $\mu$ C at 500 Ω
Maximum currentdensity	13.3 mA/cm²	13.3 mA/cm²
Maximum powerdensity	0.000088 W/cm²	0.000088 W/cm²
Timer range inminutes	720 minutes max (two 6-hour runtimes)	1800 minutes max (one 30-hourrun time)
Power source	One 3V lithium coin cell	One 3V lithium coin cell
Weight	10 g	10 g
Dimensions	7.8" x 1.2" x 0.4"	7.8" x 1.2" x 0.4"
Patient contactingmaterials	Hydrogel (KM40A)	Hydrogel (KM10T)
Parameter	ProposedgekoTM W-2	PredicategekoTM Plus R-2 (K180082)
Housing material	PolypropylenePlastic injection molding	PolypropylenePlastic injection molding

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The differences between the proposed geko™ W-2 and the predicate geko™ PWS R-2 model are:

. More stimulus levels are available to the user: 10 in the geko™ W-2 as compared to 8 in the qeko™ Pus R-2. The qeko W-2 offers two additional short pulse widths (25 & 35 us) that are below the lowest pulse width available on the predicate models.
. The geko™ W-2 provides two doses of 6 hours each, with an enforced rest of 6 hours minimum between the doses as compared to the single 30 hour run time for a geko™ Plus R-2.
. The geko™ W-2 uses KM40A instead of KM10T hydrogel.

The reason for these changes is to provide a geko model for patients who only require a lower level or stimulation and/or have sensitive skin. The geko W-2 provides a full range of stimulus intensities including two levels below those currently available for the geko™ Plus R-2. In addition, the KMT40A hydrogel of the geko W-2 has a lower adhesive strength and may be less irritative to sensitive skin than the KMT10T hydrogel used in the other geko models, including the geko PMS R-2. Finally, the 6 hour off treatment protocol gives sensitive skin a chance to rest in between treatment sessions.

Because the geko™ W-2 is limited to 6 hour treatment durations with a minimum of 6 hour rest between treatments, the device is not indicated for prevention of venous thrombosis, which requires continuous (or near continuous) therapy for longer than 6 hours. Therefore, the indications for use of the geko™ W-2 are a subset of the prior geko models. Otherwise, as can be seen from the Technical Comparison Table, the indications for use, technical specifications, mechanism of action, and device operation for the geko™ W-2 are the same as for the predicate device.

H. Design Validation Activities

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:

Biocompatibility testing for the new hydrogel for medical devices in contact with intact skin:

Cytotoxicity testing according to ISO 10993-5 o
Sensitization and Irritation testing according to ISO 10993-10 O

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The testing demonstrated that the KM40A hydrogel is biocompatible for its intended use contact.

Electrical safety testing was not needed as there are no changes in the geko W-2 as compared to the predicate geko™ Plus R-2 related to the electrical hardware.

Electromagnetic compatibility testing was conducted to IEC 60601-1-2:2014 Medical electrical equipment - Part 1-2: General requirements for basic safety and essential performance - Collateral standard: Electromagnetic disturbances - Requirements and tests. Although no electronic hardware changes were made to the geko W-2 as compared to the geko™ Pus R-2, EMC testing was conducted to assure compliance to the current version of the standard. Testing included all requirements for a non-rechargeable, battery powered medical device. Testing was conducted with the device in continuous operating mode at the highest stimulus setting. All tests were passed.

Hardware/Firmware testing – As with the prior geko models, the geko™ W-2 hardware and firmware were tested together in order to verify the correct functioning of the device. All tests were passed. Testing included:

. Verification of output waveform characteristics via oscilloscope output tracings at 500Ω, 2kΩ and 10kΩ
Validation of all geko™ W-2 hardware and firmware functionality .

Performance testing - The durability of the device when used multiple times was verified under internal test protocols that included: 1) assessing the device operation when applied and removed from a test substrate 100 times; and 2) assessing device adhesion when applied and removed for a total of 10 use cycles. All test samples passed all repeat test cases.

l. Conclusion

The information and testing presented in this 510(k) demonstrated that the geko™ W-2 is substantially equivalent to the predicate geko device models, specifically the geko™ Plus R-2, for the indications for use of increasing local circulation and edema reduction.

Regulation Number and Section

§ 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).