(145 days)
- Increasing local blood circulation
- Edema reduction
- Immediate post-surgical stimulation of the calf muscles to prevent venous thrombosis
- Stimulation of the calf muscles to prevent venous thrombosis in non-surgical patients at risk for venous thromboembolism
The geko™ T-2 and geko™ T-3 are single patient use, disposable (after 24 hours), fully integrated neuromuscular stimulator devices. Each model is composed of a constant current pulse generator with embedded software and a lithium-ion battery enclosed in a 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 devices are 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 a follows depending on the device model:
- geko™ T-2: 7 levels ranging from 50 usec to 400 µsec @ 27 mA
- geko™ T-3: 11 levels ranging from 35 to 280 µsec @ 27 mA, 280 to 400 µsec @ . 38 mA, and 400 to 560 µsec at 54 mA
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 for all device models and is used to isometrically stimulate the leg and foot muscles with a cadence and energy similar to that of walking.
Both device models have the same principles of operation and the same indications for use. The choice of device model depends on the level of stimulation needed to achieve a visible contraction (twitch) of the patient's calf and dorsiflexion of the foot.
The provided text describes a 510(k) premarket notification for the geko™ T-2 and geko™ T-3 Neuromuscular Stimulators, primarily focusing on adding a new indication for "Stimulation of the calf muscles to prevent venous thrombosis in non-surgical patients at risk for venous thromboembolism."
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. A table of acceptance criteria and the reported device performance
The document does not explicitly state formal "acceptance criteria" with specific numerical targets. Instead, the performance is reported in terms of observed VTE rates for different prophylaxis methods. The primary comparison is non-inferiority to Intermittent Pneumatic Compression (IPC).
| Acceptance Criteria Category | Reported Device Performance (geko™ only group) | Comparison Group (IPC only group) |
|---|---|---|
| Effectiveness (VTE Prevention) | 0% incidence of VTE within 90 days (0/122 patients) | 2.4% incidence of VTE within 90 days (11/463 patients) |
| Non-Inferiority to IPC | The geko™ was non-inferior to IPC within 0.5% (p=0.05) in preventing VTE. | N/A |
| Safety and Tolerability | No adverse device-related events reported. | 81 subjects switched from IPC to geko™ due to non-compliance or dissatisfaction with IPC. |
2. Sample size used for the test set and the data provenance
- Sample Size for Effectiveness Testing (geko™ only group): 122 patients
- Total Patients in Study: 1000 patients (subdivided into various prophylaxis groups)
- Data Provenance:
- Country of Origin: Royal Stoke University Hospital (RSUH) in Stoke-On-Trent, England, UK.
- Retrospective or Prospective: The study was conducted between November 1, 2016, and March 3, 2018, and patients were followed for 90 days post-discharge. This description indicates a prospective observational clinical study, where patients were entered and followed over time. However, the study is referred to as a "real-world clinical study" and not a "randomized, controlled clinical study."
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
The document does not specify the number of experts used to establish the ground truth (diagnosis of VTE) or their qualifications. It states that patients were admitted with "a confirmed diagnosis of acute stroke" and were "assessed for VTE risk." VTE incidence was then assessed over 90 days. It is implied that standard hospital protocols and medical professionals (likely clinicians, radiologists for imaging verification) would have established these diagnoses, but specific details about expert reviewers for VTE adjudication are not provided.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
The document does not specify any formal adjudication method (like 2+1 or 3+1) for confirming VTE diagnoses within the study. It refers to patients being "assessed for incidence of VTE," which usually implies standard clinical diagnostic practices.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
The study described is a clinical effectiveness study of a medical device (neuromuscular stimulator), not a diagnostic imaging AI study. Therefore, an MRMC comparative effectiveness study involving human readers and AI assistance was not conducted and is not relevant to this submission. The device is a physical stimulator, not an AI diagnostic tool.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This question is not applicable. The device is a physical neuromuscular stimulator and does not involve an algorithm working in "standalone" mode in the context of AI. Its performance is directly tied to its physical application to a patient.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The ground truth for effectiveness was based on the incidence of Venous Thromboembolism (VTE) within a 90-day follow-up period. This is outcomes data (clinical endpoint). While not explicitly stated, the diagnosis of VTE would presumably have relied on standard clinical diagnostic methods, which often include imaging (e.g., ultrasound, venography) confirmed by medical professionals.
8. The sample size for the training set
This question is not applicable. The geko™ device is a physical medical device and does not involve a "training set" in the context of machine learning. The clinical study investigated its direct physiological effect.
9. How the ground truth for the training set was established
This question is not applicable, as there is no "training set" for this type of device.
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September 18, 2019
Firstkind Limited % Sheila Hemeon-Heyer President Heyer Regulatory Solutions LLC 125 Cherry Lane Amherst, Massachusetts 01002
Re: K191113
Trade/Device Name: geko™ T-2 and geko™ T-3 Neuromuscular Stimulators Regulation Number: 21 CFR 890.5850 Regulation Name: Powered Muscle Stimulator Regulatory Class: Class II Product Code: IPF Dated: April 23, 2019 Received: April 26, 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/ofdocs/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 mediation-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 T. Ballard -S
For Vivek Pinto, Ph.D. Director (Acting) 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) K191113
Device Name
geko T-2 and geko T-3 Neuromuscular Stimulators
Indications for Use (Describe)
- · Increasing local blood circulation
- · Edema reduction
- · Immediate post-surgical stimulation of the calf muscles to prevent venous thrombosis
- · Stimulation of the calf muscles to prevent venous thrombosis in non-surgical patients at risk for venous thromboembolism
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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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: | +44 (0) 845 222 2921 |
| Email: | neil.buckley@firstkindmedical.com |
- B. Date Prepared: September 18, 2019
C. Device Name and Classification Information:
| Trade Name: | geko™ T-2 and geko™ T-3 Neuromuscular Stimulators |
|---|---|
| Classification Name: | Stimulator, Muscle, Powered |
| Product Code, CFR: | IPF, 21 CFR 890.5850 |
| Panel code: | 89 |
| Class: | II |
| Predicate Devices: | K180082 for geko™ T-2K181059 for geko™ T-3 |
Device Description: ய்
D.
The geko™ T-2 and geko™ T-3 are single patient use, disposable (after 24 hours), fully integrated neuromuscular stimulator devices. Each model is composed of a constant current pulse generator with embedded software and a lithium-ion battery enclosed in a 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 devices are 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 a follows depending on the device model:
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- geko™ T-2: 7 levels ranging from 50 usec to 400 µsec @ 27 mA
- geko™ T-3: 11 levels ranging from 35 to 280 µsec @ 27 mA, 280 to 400 µsec @ . 38 mA, and 400 to 560 µsec at 54 mA
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 for all device models and is used to isometrically stimulate the leg and foot muscles with a cadence and energy similar to that of walking.
Both device models have the same principles of operation and the same indications for use. The choice of device model depends on the level of stimulation needed to achieve a visible contraction (twitch) of the patient's calf and dorsiflexion of the foot.
F. Indications for Use:
- Increasing local blood circulation
- Edema reduction ●
- o Immediate post-surgical stimulation of the calf muscles to prevent venous thrombosis
- . Stimulation of the calf muscles to prevent venous thrombosis in non-surgical patients at risk for venous thromboembolism
G. Technical Comparison with the Predicate Device and Discussion of Differences
As shown in the table below, there have been no technological changes to the geko™ device models since they were previously 510(k) cleared. The sole purpose of this 510(k) is to add a new indication for use for prevention of venous thrombosis in non-surqical patients at risk for venous thromboembolism (VTE). The new indication for use is supported by clinical data summarized in Section H.
| Parameter | Predicate geko™T-2 | Proposed geko™T-2 | Predicate geko™T-3 | Proposed geko™T-3 |
|---|---|---|---|---|
| 510(k) # | K180082 | K191113 | K181059 | K191113 |
| Indications forUse | Increasing local●blood circulationEdema reduction●Immediate post-●surgical stimulationof calf muscles toprevent venousthrombosis | Increasing localblood circulationEdema reduction●Immediate post-surgicalstimulation of calfmuscles toprevent venousthrombosisStimulation of thecalf muscles toprevent venousthrombosis innon-ambulatory | Increasing local●blood circulationEdema reductionImmediate post-surgical stimulationof calf muscles toprevent venousthrombosis | · Increasing localblood circulationEdema reduction●Immediate post-●surqicalstimulation of calfmuscles toprevent venousthrombosisStimulation of the●calf muscles toprevent venousthrombosis innon-ambulatory |
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| Parameter | Predicate geko™T-2 | Proposed geko™T-2 | Predicate geko™T-3 | Proposed geko™T-3 |
|---|---|---|---|---|
| patients | patients | |||
| Number ofoutput modes | Single mode with 7discrete pulse widthsettings which definethe stimulation levels | Same | Single mode with 11discrete pulse widthsettings which definethe stimulation levels | Same |
| Number ofoutput channels | Single | Same | Single | Same |
| Method ofstimulusregulation | Current regulated | Same | Current regulated | Same |
| Microprocessorcontrolled? | Yes | Same | Yes | Same |
| Automaticoverload trip | Yes | Same | Yes | Same |
| Automatic no-load trip | Yes | Same | Yes | Same |
| Automatic shut-off | Yes | Same | Yes | Same |
| Patient over-ride control | Yes | Same | Yes | Same |
| Indicatordisplays | Same | Same | ||
| - On/Off status- Low battery- Stimulus level | YesYes (device switchesoff)Yes. Stimulation level(pulse width) isindicated by thenumber of times theLED flashes insequence, e.g., asingle flash for Level1 (50 µs/27 mA) up to7 flashes for Level 7(400 µs/27 mA) | YesYes (device switchesoff)Yes. Stimulation level(pulse width) isindicated by thenumber of times theLED flashes insequence, e.g., asingle flash for Level 1(35 µs/27 mA) up to11 flashes for Level 11(560 µs/54 mA). | ||
| Waveform | Asymmetrical,biphasic, rectangularwaveform with chargebalancing secondphase | Same | Asymmetrical,biphasic, rectangularwaveform with chargebalancing secondphase | Same |
| Maximumoutput voltage | 14.0 V @ 500 Ω53.5 V @ 2000 Ω255 V @ 10,000 ΩAll voltages (±10%) | Same | 27.0 V @ 500 Ω108 V @ 2000 Ω255 V @ 10,000 ΩAll voltages (±10%) | Same |
| Maximumoutput current | 27 mA @ 500 Ω27 mA @2000 Ω25.5 mA @ 10,000 Ω | Same | 54 mA @ 500 Ω54 mA @ 2000 Ω54 mA @ 10,000 Ω | Same |
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| Parameter | Predicate geko™T-2 | Proposed geko™T-2 | Predicate geko™T-3 | Proposed geko™T-3 |
|---|---|---|---|---|
| All currents (±15%) | All currents (±15%) | |||
| Pulse widths | 50, 70, 100, 140, 200,280, 400 $\mu$ s | Same | 35, 50, 70, 100, 140,200, 280, 400, 560 $\mu$ s | Same |
| Frequency | 1 Hz, fixed | Same | 1 Hz, fixed | Same |
| Net charge | 0 $\mu$ C at 500Ω,capacitor coupled | Same | +/- 0.1 $\mu$ C at 500Ω,phase balancing | Same |
| Maximum phasecharge | 18.3 $\mu$ C at 500 Ω | Same | 40 $\mu$ C at 500 Ω | Same |
| Maximumcurrent density | 6.67 mA/cm² | Same | 13.3 mA/cm² | Same |
| Maximumpower density | 0.000044 W/cm² | Same | 0.000088 W/cm² | Same |
| Timer range inminutes | 1800 min max (30 hrrun time) | Same | 1800 min max (30 hrrun time) | Same |
| Power source | One 3V lithium coincell | Same | One 3V lithium coincell | Same |
| Weight | 10 g | Same | 10 g | Same |
| Dimensions | 7.8" x 1.2" x 0.4" | Same | 7.8" x 1.2" x 0.4" | Same |
| Patientcontactingmaterials | Hydrogel (KM10T) | Same | Hydrogel (KM10T) | Same |
| Housingmaterial | PolypropylenePlastic injectionmolding | Same | PolypropylenePlastic injectionmolding | Same |
H. Discussion of Performance Data
A clinical study was conducted to demonstrate the safety and effectiveness of the geko™ in preventing venous thromboembolism (VTE) in a group of patients hospitalized following stroke. The study included all patients admitted to and followed by the Acute Stoke Unit (ASU) at the Royal Stoke University Hospital (RSUH) in Stoke-On-Trent England between November 1, 2016 and March 3, 2018, with a confirmed diagnosis of acute stroke (ischemic or haemorrhagic) or transient ischemic attack (TIA). VTE prophylaxis was prescribed for all stroke patients who were non-ambulatory, defined as not able to walk unaided, and at risk for VTE according to hospital protocol. VTE prophylaxis was by pharmacological means (anticoagulants) unless contraindicated in which case mechanical intermittent pneumatic compression (IPC) was employed. Patients for whom IPC was contraindicated were prescribed the geko™. Patients who began with IPC but became intolerant or non-compliant were allowed to switch to the geko™. Patients who refused VTE prophylaxis were also followed in the study. Patients were assessed for VTE risk within 24 hours of admission, and IPC or geko™, when prescribed, was begun within 3 days of admission for 98.7% (657/666) of the patients. Both IPC and geko™ were applied bi-laterally and used 24
{7}------------------------------------------------
hours/day until hospital discharge. Patients were assessed for incidence of VTE for 90 days following hospital discharge.
A total of 1000 patients were entered into this clinical study. All patients were followed for the 90 day study period. The methods of VTE prophylaxis employed during their period of hospital admission were:
- Pharmacological anti-coagulation (N=125)
- . IPC only (N=463)
- . geko™ only (N=122)
- IPC & geko™ (started with IPC but switched to geko™ due to non-tolerance or noncompliance with IPC) (N=81)
- Refused VTE prophylaxis treatment (N=22)
- No VTE prophylaxis treatment required (N=187) ●
The results of this study were that of the 122 patients who received VTE prophylaxis with the geko™ only, none experienced a VTE within the 90-day period of this study. By comparison, 2.4% (11/463) of the patients who received VTE prophylaxis with IPC only, 1.2% (1/81) of patients who started with IPC then switched to geko™, and 4.8% (1/22) of patients who refused VTE prophylaxis experienced a VTE within the 90-day period of this study. Comparison of the results between the geko™ only and IPC only groups demonstrates that the geko™ was non-inferior to IPC within 0.5% (p=0.05) in preventing VTE in this patient population.
In addition, geko™ was shown to be a safe and well-tolerated therapy. While no adverse device-related events (serious or otherwise) were reported for either geko™ or IPC in this study, 81 subjects switched from IPC to geko™ due to non-compliance or dissation with the IPC.
This was a real-world clinical study. The safety and effectiveness of the devices for prevention of venous thrombosis in non-surgical patients has not been demonstrated in a randomized, controlled clinical study.
. Conclusion
The clinical data presented in this 510(k) supports the safety and effectiveness of the geko™ devices when used to prevent venous thrombosis in hospitalized patients who are at risk for VTE. Therefore, this 510(k), with the new indication for use, is substantially equivalent to the previously cleared 510(k)s for the geko™ T-2 and geko™ T-3.
§ 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).