(90 days)
The geko W-2 is indicated for:
- Increasing local blood circulation
- Edema reduction
- Increasing microcirculatory blood flow in lower limb soft tissue of patients with venous insufficiency and/or ischemia while the device is active
The geko™ W-2 Neuromuscular Stimulator (geko™ W-2) 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.
The provided text describes the acceptance criteria and the study results for the geko™ W-2 device, particularly focusing on the added indication for increasing microcirculatory blood flow.
Here's a breakdown of the requested information:
1. Table of Acceptance Criteria and Reported Device Performance
The FDA clearance is based on proving substantial equivalence for the new indication ("Increasing microcirculatory blood flow in lower limb soft tissue of patients with venous insufficiency and/or ischemia while the device is active"). The acceptance criteria are implicitly met by demonstrating this substantial equivalence through clinical study outcomes. The reported device performance is the statistically significant increase in both flux and pulsatility (measures of microcirculatory blood flow).
| Acceptance Criteria (Stated Goal) | Reported Device Performance |
|---|---|
| Increase microcirculatory blood flow in lower limb soft tissue of patients with venous insufficiency and/or ischemia while the device is active. | Study #1 (Venous Insufficiency): Statistically significant increases in both flux and pulsatility (measures of blood flow via LSCI) were measured when the geko was turned on (active) as compared to the resting state in patients with venous insufficiency. This confirmed the device's ability to increase blood flow in small vessels of the legs while active. Study #2 (Ischemia): Statistically significant increases in both flux and pulsatility (measures of blood flow via LSCI) were measured when the geko was turned on (active) as compared to the resting state in patients with ischemia. This confirmed the device's ability to increase blood flow in small vessels of the legs while active. |
2. Sample Sizes Used for the Test Set and Data Provenance
- Study #1:
- Sample Size: 16 subjects (10 males, 6 females).
- Data Provenance: United Kingdom (Ealing Hospital), Retrospective (published study). The text states "This study was conducted to evaluate..." suggesting it was a specific study, not necessarily retrospective in the sense of analyzing existing patient records, but rather a completed study whose data was submitted.
- Study #2:
- Sample Size: 8 subjects (4 males, 4 females).
- Data Provenance: United Kingdom (Aneurin Bevan University Health Board and Cardiff and Vale University Health Board), Retrospective (published study). Similar to Study #1, it was a completed study.
- Study #3 (Safety data):
- Sample Size: 25 patients (22 males, 3 females).
- Data Provenance: UK (Welsh Wound Innovation Centre), Retrospective (published study).
- Study #4 (Safety data, interim report):
- Sample Size: 33 subjects (21 male, 12 female).
- Data Provenance: UK and EU (multi-center study), Prospective (ongoing study, interim report).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The provided information does not specify the use of experts to establish a "ground truth" through a consensus read or similar method for the microcirculatory blood flow measurements. The studies used objective measurements (Laser Speckle Contrast Imaging - LSCI) to quantify blood flow. The "ground truth" here is the direct physiological measurement of blood flow changes.
4. Adjudication Method for the Test Set
Not applicable. As noted above, the "ground truth" was established through direct physiological measurements (LSCI), not through human assessment requiring adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, And What Was the Effect Size of How Much Human Readers Improve With AI vs Without AI Assistance
Not applicable. The geko™ W-2 is a physical medical device (neuromuscular stimulator), not an AI algorithm for image analysis or diagnosis. Therefore, MRMC studies involving human readers and AI assistance are not relevant to this device.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Not applicable. This is not an AI algorithm. The device's performance is standalone in the sense that it operates as designed to stimulate muscle, leading to the physiological effect of increased blood flow.
7. The Type of Ground Truth Used
The ground truth for the effectiveness studies (Study #1 and #2) was objective physiological measurement: Laser Speckle Contrast Imaging (LSCI) data, which quantifies microcirculatory blood flow (flux and pulsatility).
8. The Sample Size for the Training Set
Not applicable. The geko™ W-2 device is a hardware device with embedded software that controls its function (e.g., pulse rate, intensity). It is not an AI/machine learning model that undergoes a "training" phase with a dataset.
9. How the Ground Truth for the Training Set Was Established
Not applicable. See point 8.
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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 in blue, with the words "U.S. FOOD & DRUG ADMINISTRATION" in blue as well. The FDA is a federal agency responsible for regulating and supervising the safety of food, drugs, and other products.
November 29, 2021
Firstkind Limited % Sheila Hemeon-Heyer President Heyer Regulatory Solutions LLC 125 Cherry Lane Amherst, Massachusetts 01002
Re: K212762
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: August 31, 2021 Received: August 31, 2021
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); 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,
Amber Ballard, PhD Assistant Director DHT5B: Division of Neuromodulation and Physical Medicine Devices OHT5: Office of Neurological and Physical Medicine Devices Office of Product Evaluation and Ouality Center for Devices and Radiological Health
Enclosure
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Indications for Use
510(k) Number (if known) K212762
Device Name
geko W-2
Indications for Use (Describe)
The geko W-2 is indicated for:
- · Increasing local blood circulation
- · Edema reduction
• Increasing microcirculatory blood flow in lower limb soft tissue of patients with venous insufficiency and/or ischemia while the device is active
Type of Use (Select one or both, as applicable)
Prescription Use (Part 21 CFR 801 Subpart D)
| Over-The-Counter Use (21 CFR 801 Subpart C)
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Traditional 510(k) Summary
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 29, 2021
C. Device Name and Classification Information:
| Trade Name: | geko™ W-2 | |
|---|---|---|
| Common Name: | Neuromuscular Electrical Stimulator | |
| Classification Name: | Stimulator, Muscle, Powered | |
| Product Code, CFR: | IPF, 21 CFR 890.5850 | |
| Panel code: | 89 | |
| Class: | II |
- K193045, geko™ W-2 Neuromuscular Stimulator D. Predicate Device:
E. Device Description:
The geko™ W-2 Neuromuscular Stimulator (geko™ W-2) 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
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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 ●
- Increasing microcirculatory blood flow in lower limb soft tissue of patients with ● venous insufficiency and/or ischemia while the device is active
G. Technical Comparison with the Predicate Device and Discussion of Differences
The purpose of this 510(k) is to add a new indication for use of to the previously cleared geko™ W-2 device. There have been no changes to the device design, technical specifications, or operating principles. The table below demonstrates that the geko W-2 reviewed under this 510(k) is the same as the geko W-2 reviewed under K193045 except for the new indication for use.
| Parameter | Predicategeko™ W-2 (K193045) | Proposedgeko™ W-2 |
|---|---|---|
| Indications for use | Increasing local blood circulation Edema reduction | Increasing local blood circulation Edema reduction Increasing microcirculatory blood flow in lower limb soft tissue of patients with venous insufficiency and/or ischemia while the device is active |
| # Output modes | 1 | 1 |
| # Output channels- Synchronous oralternating?- Method of channelisolation? | N/A | N/A |
| Method of stimulusregulation | Current regulated | Current regulated |
| Microprocessorcontrolled? | Yes | Yes |
| Automatic overloadtrip | Yes | Yes |
| Automatic no-load trip | Yes | Yes |
| Automatic shut-off | Yes | Yes |
| Patient over-ride | Yes | Yes |
| Parameter | Predicategeko™ W-2 (K193045) | Proposedgeko™ W-2 |
| control | ||
| Indicator displays- On/Off status- Low battery- Stimulus level | YesYesYes (device switches off)Yes. Stimulation level (pulse width) is indicated by the number of times the LED flashes in sequence, e.g., a single flash for Level 1 (25 μs/54 mA) up to 10 flashes for Level 10 (560 μs/54 mA). | YesYesYes (device switches off)Yes. Stimulation level (pulse width) is indicated by the number of times the LED flashes in sequence, e.g., a single flash for Level 1 (25 μs/54 mA) up to 10 flashes for Level 10 (560 μs/54 mA). |
| Waveform | Asymmetrical, biphasic, rectangular waveform with charge balancing second phase | Asymmetrical, biphasic, rectangular waveform with charge balancing second phase |
| Maximum outputvoltage | 27.0 V @ 500 Ω108 V @ 2000 Ω255 V @ 10,000 ΩAll voltages (±10%) | 27.0 V @ 500 Ω108 V @ 2000 Ω255 V @ 10,000 ΩAll voltages (±10%) |
| Maximum outputcurrent | 54 mA @ 500 Ω54 mA @ 2000 Ω25.5 mA @ 10,000 ΩAll currents (±15%) | 54 mA @ 500 Ω54 mA @ 2000 Ω25.5 mA @ 10,000 ΩAll currents (±15%) |
| Pulse widths | 25, 35, 50, 70, 100, 140, 200, 280, 400, and 560 μs | 25. 35. 50, 70, 100, 140, 200, 280, 400 and 560μs |
| Frequency | 1 Hz, fixed | 1 Hz, fixed |
| Net charge | 0 μC at 500 Ω, capacitor coupled | 0 μC at 500 Ω, capacitor coupled |
| Maximum phasecharge | 40 μC at 500 Ω | 40 μC 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 in minutes | 720 minutes max (two 6-hour run times) | 720 minutes max (two 6-hour run times) |
| 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 (KM40A) |
| Parameter | Predicategeko™ W-2 (K193045) | Proposedgeko™ W-2 |
| Housing material | Polypropylene | Polypropylene |
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There are no differences between the proposed and predicate geko™ W-2 to discuss other than the new indication for use.
H. Discussion of Performance Data
Data from four clinical studies were submitted in this 510(k) to support the safety and effectiveness of the geko™ W-2 device to increase microcirculatory blood flow in the lower limbs of patients with venous insufficiency and/or ischemia. Studies #1 and #2 were acute studies that measured increased microcirculatory blood flow in these patient populations during short-term active geko stimulation as compared to rest. Data from studies #3 and #4 demonstrated the safety of the geko when used daily over multiple weeks by these patient populations and were not used to support the effectiveness of the device. No data were provided to support the safety and effectiveness of the geko W-2 to promote wound healing. The magnitude of the clinical benefit of the geko from increased microcirculatory blood flow in patients with venous insufficiency and/or ischemia remains unclear.
Each of these studies is summarized below.
Study #1: Published in: Das S, Dhoonmoon L, Chhabra S. Microcirculatory changes in venous leq ulcers using intermittent electrostimulation of common peroneal nerve. Int Wound J 2021 Apr; 18(2):187-93.
This study was conducted to evaluate the effect of geko stimulation on both arterial and venous microcirculatory blood flow in the lower limb of patients with venous insufficiency and ischemia using Laser Speckle Contrast Imaging (LSCI). Sixteen subjects who were being treated with compression therapy for their VLU at the Ealing Hospital in the United Kingdom participated in this study, including 10 males and 6 females with a mean age of 68 (range 61-79) years and a mean BMI of 27.9 kg/m² (range 25.9-29.5 kg/m²). All microcirculatory blood flow measurements were obtained with the subjects at rest in a seated position. LSCI measurements were obtained for 2 minutes under each of the following conditions: 1) immediately following a 10-minute stabilization period with the geko turned off; and 2) immediately following a 10-minute stabilization period with the geko turned on and actively stimulating the peroneal nerve. The only difference between the two sets of measurements was the geko activation status. Statistically significant increases in both flux and pulsatility were measured when the geko was turned on (active) as compared to the resting state. The results of this study confirmed that use of the geko can increase blood flow in the small vessels (micro-circulation) of the legs in patients with venous insufficiency while the device is active. The measurement of increased blood flow in this study was made during a short (10-minute) period of active device use, and no data were provided by this study to support increased
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microcirculatory blood flow during longer device use durations or in the immediate or prolonged reperfusion stages. These data do not support that the geko W-2 has any benefit for wound healing. Adverse events were not reported in this acute study.
Study #2: Published in: Bosanquet D, Ivins N, Jones N, Harding K. Microcirculatory flux and pulsatility in arterial leg ulcers is increased by intermittent neuromuscular electrostimulation of the common peroneal nerve. Ann Vasc Surg 2021 Feb; 71:308-14.
This study was conducted to evaluate the effect of geko stimulation on both arterial and venous microcirculatory blood flow in the lower limb of patients with ischemia using Laser Speckle Contrast Imaging (LSCI). Eight subjects who were being treated under the Aneurin Bevan University Health Board and Cardiff and Vale University Health Board in the United Kingdom participated in this study. The subjects included 4 males and 4 females with a mean age of 72 ± 8 years, mean BMI of 25.2 ± 3.1 kg/m2, and mean ABPI of 0.5 ± 0.05. All of the subjects had peripheral artery disease and 50% of the subjects had Type 2 diabetes. All microcirculatory blood flow measurements were obtained with the subjects at rest in a seated position. LSCI measurements were obtained for 2 minutes under each of the following conditions: 1) immediately following a 30-minute stabilization period with the geko turned off; and 2) immediately following a 30-minute stabilization period with the geko turned on and actively stimulating the peroneal nerve. The only difference between the two sets of measurements was the geko activation status. Statistically significant increases in both flux and pulsatility were measured when the geko was turned on (active) as compared to resting state. The results of this study confirm that use of the geko can increase blood flow in the small vessels (microcirculation)of the legs of patients with ischemia while the device is active. The measurement of increased blood flow in this study was made during a short period (30 minutes) while the device was active, and not data were provided by this study to support increased blood flow after period of use longer than 30 minutes or in the immediate or prolonged reperfusion stages. These data do not support that the geko W-2 has any benefit for wound healing. Adverse events were not reported in this acute study.
Study #3: Published in: Jones N, Ivins N, Ebon V, Hagelstein S, Harding K. Neuromuscular electrostimulation on lower limb wounds. Brit J Nurs 2018; 27(20):516-21.
This study reported on 25 patients with compromised lower limb circulation being treated at the Welsh Wound Innovation Centre in the UK between September 2015 and January 2017: 17 with venous leq ulcers (VLU), 3 with mixed leg ulcers (MLU), and 3 with diabetic foot ulcers (DFU). This study population included 22 males and 3 females, with a mean age of 69 years (53 to 85 years). All subjects wore the geko in addition to their standard care (i.e., dressing changes, off-loading, and compression, as appropriate) for 6 hours (continuously) per day at home for 8 weeks. Only one adverse event, irritation beneath the electrodes, was reported over the duration of the study. This study demonstrates that patients with compromised lower limb blood flow can safely use the
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geko on a prolonged (4 week) daily basis for 6 hours a day. These data do not provide sufficient data to support that the geko W-2 is safe or effective for wound healing.
Study #4: Interim Report of Ongoing Study - Long-term geko Use by Subjects with Chronic Leg Wounds
Although this study is not yet completed, Firstkind prepared an interim report of the available study data to provide additional evidence related to the safety of long-term use of the geko W-2 in patients with compromised lower limb circulation. This is an ongoing multi-center study at sites in the UK and EU. As of January 21, 2021, safety data were available for 33 subjects (21 male, 12 female, age ranging from 21-93 years) treated with the geko for either 6 hours per day for 4 weeks (n=15) or 12 hours per day for 4 weeks (n=18). No serious adverse events (SAEs), whether device related or not, were reported for these 33 subjects. A total of 11 device related, non-serious adverse events (AEs) were reported thus far, all of which were mild skin reactions beneath the electrodes: 4 cases in the 15 subjects treated for 6 hours per day (26.7% event rate) and 7 cases in the subjects treated for 12 hours per day (38.9% event rate). None of the skin reactions resulted in a subject being terminated early from the study, although one subject did choose to stop using the device following their completion of the study treatment phase as a result of their rash. These data do not provide sufficient data to support that the geko W-2 is safe or effective for wound healing.
l. Conclusion
The clinical data presented in this 510(k) demonstrate that that the geko™ W-2 is substantially equivalent to the predicate geko™ W-2 device for the indication of increasing microcirculatory blood flow in lower limb soft tissue of patients with venous insufficiency and/or ischemia.
§ 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).