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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).

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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• Increasing local blood circulation
• Edema reduction

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.

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.

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.

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• 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).

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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• Increasing local blood circulation
• Immediate post-surgical stimulation of the calf muscles to prevent venous thrombosis
• Edema reduction

The geko™ T-3 Neuromuscular Stimulator (geko™ T-3) is single-patient use and disposable, with fully integrated electronics 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 geko™ T-3 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 11 levels: 35, 50, 70, 100, 140, 200 or 280 at 27 mA; 280 or 400 at 38 mA; and 400 or 560 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 and is used to isometrically stimulate the calf and foot muscles with a cadence and energy similar to that of walking.

Here's a breakdown of the acceptance criteria and the study proving the device meets them, based on the provided FDA 510(k) summary for the geko™ T-3 Neuromuscular Stimulator:

This document is a premarket notification (510(k)) submission, which aims to demonstrate that a new medical device is substantially equivalent to a legally marketed predicate device. For devices seeking 510(k) clearance, the "acceptance criteria" are primarily established by showing that the new device has the same indications for use and similar technological characteristics to a predicate device, and that any differences do not raise new questions of safety and effectiveness.

The core "study" proving the device meets the acceptance criteria in a 510(k) context is a comparative analysis with predicate devices and verification/validation testing of the device's adherence to relevant performance and safety standards.

1. Table of Acceptance Criteria and Reported Device Performance

For the geko™ T-3 Neuromuscular Stimulator, the "acceptance criteria" are largely met by demonstrating substantial equivalence to its predicate devices (geko™ T-2 and geko™ Plus R-2). The reported device performance is shown by its adherence to technical specifications and compliance with recognized electrical safety and electromagnetic compatibility standards.

Study Description (for 510(k) Substantial Equivalence)

The "study" in this context is a series of verification and validation activities conducted by the manufacturer to demonstrate substantial equivalence to predicate devices and adherence to regulatory standards.

2. Sample Size Used for the Test Set and Data Provenance:

• Sample Size: Not applicable in the conventional sense of a clinical trial patient sample size. For this 510(k) submission, the "test set" consisted of the geko™ T-3 device itself and its components. The document describes verification and validation testing (e.g., electrical safety, EMC, hardware/firmware functionality). The sample size for these tests refers to the number of devices or components tested to ensure they meet specifications and standards. This typically involves testing a sufficient number of units to ensure reliability and compliance, though the exact number of units tested is not specified in this summary.
• Data Provenance: The testing was conducted as part of the company's design change procedures. The manufacturer, Firstkind Limited, is based in High Wycombe, UK. This suggests the testing data originates from the UK. The document doesn't specify if the testing was retrospective or prospective, but typically design verification and validation testing is prospective to the submission.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:

• This type of information is generally not required for a 510(k) submission that relies on technical equivalence and performance testing rather than clinical data interpretations by experts (like for imaging AI).
• The "ground truth" here is adherence to engineering specifications and international safety standards. The "experts" would be the certified testing bodies and internal quality/regulatory engineers with expertise in electrical engineering, medical device standards, and quality management systems (e.g., IEC standards, ISO 13485). Their qualifications are typically implied by their accreditation and certifications to perform such tests.

4. Adjudication Method for the Test Set:

• Not applicable as this is not a study involving human readers or interpretations of complex data like medical images. The "adjudication" is compliance with documented test procedures and objective measurements against established engineering and safety standards.

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:

• No, an MRMC comparative effectiveness study was not done. This device is a neuromuscular stimulator for physical indications, not an AI imaging diagnostic tool. Therefore, MRMC studies and human reader improvement metrics are not relevant to this submission.

6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done:

• This concept is typically relevant for AI/ML algorithms. For this device, the "standalone" performance refers to the device's ability to operate according to its specifications and comply with safety standards independent of human intervention in its function. The Hardware/Firmware Testing section mentions "Verification of output waveform characteristics via oscilloscope output tracings" and "Validation of all geko™ T-3 hardware and firmware functionality." This is essentially "standalone performance" testing for a hardware device with embedded software.

7. The type of ground truth used:

• The ground truth for the device's "performance" and "safety" is established by:
  • Engineering Specifications: The defined output parameters (current, voltage, pulse width, frequency, net charge, etc.) and physical characteristics.
  • International Standards: Compliance with recognized medical electrical equipment (IEC 60601-1, IEC 60601-2-10, IEC 60601-1-11) and electromagnetic compatibility (EN 60601-1-2) standards.
  • Comparison to Predicate Devices: The established safe and effective design and performance of the legally marketed predicate devices (geko™ T-2 and geko™ Plus R-2).

8. The sample size for the training set:

• Not applicable. This device is hardware with embedded software, not an AI/ML device that requires a "training set" of data in the common sense for model development. The software capabilities are validated through traditional software verification and validation activities (e.g., unit testing, integration testing, system testing).

9. How the ground truth for the training set was established:

• Not applicable for AI/ML training data. Any "ground truth" for the device's design and embedded software was established through engineering design principles, risk analysis, and adherence to performance specifications and relevant international standards.

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• Increasing local blood circulation
• Immediate post-surgical stimulation of the calf muscles to prevent venous thrombosis
• Edema reduction

The geko™ T-2 and geko™ Plus R-2 Neuromuscular Stimulator devices were previously described in K152677 and K160299, respectively. There have been no changes to the design, technical specifications, or manufacturing of these devices since previously cleared. The devices are single patient use and disposable with fully integrated electronics 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 to one of seven levels for the geko™ T-2 (ranging from 50 usec to 400 usec) and one of eight levels for the geko™ Plus R-2 (ranging from 50 usec to 560 usec). The constant current output at each pulse width setting is nominally 27 mA for the geko™ T-2 and 54 mA for the geko™ Pus R-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 for both devices and is used to isometrically stimulate the leg and foot muscles with a cadence and energy similar to that of walking.

The provided document is a 510(k) summary for the geko™ T-2 and geko™ Plus R-2 Neuromuscular Stimulators, seeking to add an indication for use: "Edema reduction". This document does not describe an AI/ML device, nor does it provide the kind of detailed performance study typically associated with AI/ML device clearances (e.g., acceptance criteria tables, MRMC studies, ground truth establishment methods for large datasets).

Instead, it's a premarket notification for a traditional medical device, demonstrating substantial equivalence to a predicate device for a new indication. The "performance data" section describes a small clinical study, not an AI/ML performance evaluation.

Therefore, I cannot fulfill your request for:

1. A table of acceptance criteria and reported device performance (in the context of AI/ML).
2. Sample size for a test set (as in AI/ML evaluation).
3. Number of experts and their qualifications for ground truth establishment.
4. Adjudication method.
5. MRMC study details or effect size.
6. Standalone performance for an algorithm.
7. Type of ground truth used (in the context of AI/ML).
8. Sample size for a training set.
9. How ground truth was established for a training set.

The document only provides information relevant to the clinical study conducted for the device's effectiveness in edema reduction, not an AI/ML model's performance.

Here's what the document does state regarding the clinical study (analogous to 'performance data' for this type of device):

Clinical Study Details (from Section H. Discussion of Performance Data):

• Study Type: Clinical trial (randomized).
• Purpose: To demonstrate the safety and effectiveness of the geko devices in the reduction of edema.
• Sample Size:
  • 26 subjects undergoing total hip replacement surgery.
  • geko™ device group: n=14
  • Compression stockings group: n=12 (control/comparator)
• Intervention: Randomized therapy (geko™ device or compression stockings) applied bilaterally immediately following surgery and worn continuously until hospital discharge (except for bathing/procedures). Geko™ devices changed every 24 hours.
• Measurements: Circumference measurements of operated and non-operated legs (ankle, calf, thigh) immediately prior to and following surgery, and daily until hospital discharge.
• Outcome Measure: Total leg volume determined using a conical model from circumference measurements.
• Results:
  • "Less edema formation for the subjects treated with the geko™ devices as compared to compression stockings in both the operated and non-operated legs."
  • Statistical significance reached by Day 1 post-op and continued until hospital discharge.
• Adverse Events: "No device-related adverse events or serious adverse events were reported for either the geko™ devices or compression stockings."
• Conclusion (of the study): The clinical data supports the safety and effectiveness of the geko™ devices for edema reduction.

Ground Truth (in the context of this clinical study): The 'ground truth' here would be the actual measured changes in leg circumference/volume and clinical observation of adverse events, assessed by medical staff in a hospital setting. It's not a consensus reading by experts on images, but rather direct physiological measurement and adverse event reporting.

This document is a declaration of substantial equivalence for a physical medical device, not a regulatory submission for an AI/ML diagnostic or therapeutic algorithm. Therefore, the questions related to AI/ML specific evaluation criteria are not applicable.

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• Increasing local blood circulation
• Immediate post-surgical stimulation of the calf muscles to prevent venous thrombosis

The geko™ T-2 and geko™ Plus R-2 Neuromuscular Stimulator devices were previously described in K152677 and K160299, respectively. There have been no changes to the design, technical specifications, or manufacturing of these devices since previously cleared. The devices are single patient use and disposable with fully integrated electronics 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 to one of seven levels for the geko™ T-2 (ranging from 50 µsec to 400 µsec) and one of eight levels for the geko™ Plus R-2 (ranging from 50 µsec to 560 µsec). The constant current output at each pulse width setting is nominally 27 mA for the geko™ T-2 and 54 mA for the geko™ Plus R-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 for both devices and is used to isometrically stimulate the leg and foot muscles with a cadence and energy similar to that of walking.

The provided text is a 510(k) summary for the Firstkind Limited geko™ T-2 and geko™ Plus R-2 Neuromuscular Stimulators. This document primarily focuses on a labeling modification (removal of a warning) and provides performance data related to electromagnetic compatibility, not the clinical efficacy or diagnostic performance typically associated with AI/ML device studies.

Therefore, many of the requested elements for an AI/ML device study, such as expert ground truth, adjudication methods, MRMC studies, standalone algorithm performance, and sample sizes for training/test sets for an AI model, are not applicable to this document.

However, I can extract the acceptance criteria and the (EMC) study details described:

Acceptance Criteria and Performance (Electromagnetic Compatibility)

1. Table of Acceptance Criteria and Reported Device Performance (EMC)

2. Sample Size Used for the Test Set and Data Provenance

• Test Set Description: A "gel phantom that simulated the conductive properties of the human limb" was used. This is a simulated use bench test, not human data.
• Sample Size: Not explicitly quantified in terms of number of "samples" but described as various distances (from 500mm down to 5mm), different speeds, low and high power levels, and different cutting/coagulation modes of the HF electrosurgery device. This indicates a factorial design covering different operational conditions.
• Data Provenance: This is a bench test (simulated), not from a specific country or patient cohort, and is by nature prospective as it's a controlled experiment designed for this purpose.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

• Not Applicable. This is a bench test assessing physical performance (electrical parameters, absence of burns on a phantom). Expert "ground truth" in the sense of clinical interpretation or diagnosis is not relevant here. The "ground truth" is the physical measurement of device output and observation of the phantom for burns.

4. Adjudication Method for the Test Set

• Not Applicable. As this is a bench test with objective measurements and observations, there is no need for adjudication by multiple human observers.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done

• No. This type of study is relevant for evaluating the impact of AI on human diagnostic accuracy. The study described is a bench test for electromagnetic compatibility, not a clinical diagnostic study.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

• Not Applicable. The geko™ is a neuromuscular stimulator, not an AI algorithm. Its performance is assessed directly, not via an AI model.

7. The Type of Ground Truth Used

• Experimental Measurement/Observation: The ground truth was established by direct measurement of the geko™ device's output parameters remaining within tolerance and visual/physical confirmation of the absence of burns on the gel phantom under various high-frequency electrosurgery interference conditions.

8. The Sample Size for the Training Set

• Not Applicable. The geko™ device is not an AI/ML algorithm that requires a training set.

9. How the Ground Truth for the Training Set Was Established

• Not Applicable. As there is no training set mentioned (because it's not an AI/ML device), this question is irrelevant.

In summary, the provided document details a 510(k) submission for a neuromuscular stimulator. The "performance data" highlighted refers to the device's electromagnetic compatibility (EMC) when exposed to high-frequency surgical equipment, not to the clinical or diagnostic performance of an AI/ML system. Therefore, most questions related to AI/ML study methodologies (ground truth establishment by experts, training/test sets for algorithms, MRMC studies) are not pertinent to this submission.

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The geko(TM) Plus R-2 is intended for:

• Increasing local blood circulation; and
• Immediate post-surgical stimulation of the calf muscles to prevent venous thrombosis.

The geko™ Plus R-2 Neuromuscular Stimulator (geko™ Plus R-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 casinq, 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™ Plus R-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 provided text describes a 510(k) premarket notification for the Geko™ Plus R-2 Neuromuscular Stimulator. This document focuses on demonstrating substantial equivalence to a predicate device, rather than presenting a study to prove acceptance criteria with detailed performance metrics as would be found for an AI/ML device.

Therefore, many of the requested categories for AI/ML device studies are not applicable to this submission.

Here's a breakdown of the information that can be extracted and where the document falls short for AI/ML specific criteria:

1. A table of acceptance criteria and the reported device performance

The document does not provide specific acceptance criteria in terms of performance metrics (sensitivity, specificity, etc.) for the device's intended use (increasing local blood circulation, preventing venous thrombosis). Instead, it establishes substantial equivalence based on technical specifications and safety standards compared to a predicate device.

The table on pages 6-8 is a comparison of design parameters between the predicate device (geko™ T-2) and the proposed device (geko™ Plus R-2). It highlights technical specifications rather than clinical performance acceptance criteria.

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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

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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The geko™ T-1 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-1 (geko™) Neuromuscular Stimulator 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. A single button controls the On/Off function and the intensity level of the device, which is achieved through changes in the delivered pulse width. The geko™ 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.

Here's an analysis of the provided text regarding the acceptance criteria and study for the geko™ T-1 Neuromuscular Stimulator.

It's important to note that the provided document is a 510(k) summary for a medical device, which focuses on demonstrating substantial equivalence to a predicate device rather than outright proving effectiveness through a traditional clinical trial designed around specific acceptance criteria like those for a new drug. Therefore, some of the information requested might not be explicitly stated in the context of typical "acceptance criteria" but can be inferred from the equivalence arguments.

Acceptance Criteria and Reported Device Performance

The document does not explicitly present a table of "acceptance criteria" for performance metrics in the way one might see for a diagnostic AI. Instead, it demonstrates substantial equivalence to a predicate device (SYS*STIM ME 208) by comparing various technical and functional parameters, and by showing that the device achieves similar physiological effects (increased blood flow).

The substantial equivalence argument is built around the idea that the geko™ T-1 is as safe and effective as the predicate. The "acceptance criteria" in this context are implicitly that the geko™ T-1's performance is either similar to or better than the predicate device, especially in its indicated uses.

Table of "Acceptance Criteria" (Inferred from Substantial Equivalence Comparison) and Reported Device Performance:

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