K Number
K162718
Date Cleared
2017-11-30

(427 days)

Product Code
Regulation Number
882.5810
Reference & Predicate Devices
Predicate For
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

XFT-2001D Foot Drop System is intended to address the lack of ankle dorsiflexion in patients who have sustained damage to upper motor neurons or pathways to the spinal cord. During the swing phase of walking, the XFT-2001D electrically stimulates the appropriate muscles that cause ankle dorsiflexion and may thus improve the individual's gait. Medical benefits of Functional Stimulation (FES) may include prevention/retardation of disuse attophy, increased local blood flow, muscle re-education, and maintained or increased joint range of motion.

Device Description

Nerve and Muscle Stimulator (Foot Drop System) is a battery-operated, electrical stimulator that can be used for functional electrical stimulation (FES). Nerve and Muscle Stimulator (Foot Drop System) is an external functional electrical stimulator. It is a small device that attaches to the leg just below the knee, near the head of the fibula. During a gait cycle, Nerve and Muscle Stimulator (Foot Drop System) stimulates the common peroneal nerve, which innervates the tibialis anterior and other muscles that cause dorsiflexion of the ankle. The Nerve and Muscle Stimulator (Foot Drop System) consists of the Patient Kit and the Clinician Kit. The Patient Kit comprises of all the components and accessories that the patient will take home and use. The Clinician System includes the Medical Records Management Software.

AI/ML Overview

The provided text is a 510(k) summary for the XFT-2001D Foot Drop System, which seeks to demonstrate substantial equivalence to a predicate device (WalkAide, K123972). This document primarily details a comparison of the proposed and predicate devices' technical specifications and outlines the performance testing conducted to support safety and effectiveness. It does not present a study with specific acceptance criteria and reported device performance in the context of clinical efficacy or accuracy metrics for AI/ML-driven devices.

The "Performance Data" section (Page 10) focuses on regulatory compliance testing rather than clinical study results. It mentions:

  • EMC and Electrical safety: Compliance with IEC 60601-1-2:2014, IEC 60601-1:2005, and IEC 60601-2-10:2012. These are standards for the basic safety and essential performance of medical electrical equipment, including electromagnetic disturbances and specific requirements for nerve and muscle stimulators.
  • Biocompatibility: Evaluation of electrode pads (K132588) per ISO 10993-5:2009 (in vitro cytotoxicity) and ISO 10993-10:2010 (irritation and skin sensitization).
  • Software Verification and Validation: Conducted for a "MODERATE" level of concern software, following FDA guidance for software in medical devices.

Therefore, many of the requested elements for a deep dive into AI/ML study specifics (e.g., sample size for test set, data provenance, number of experts for ground truth, adjudication methods, MRMC studies, standalone performance, training set details) are not applicable or not present in this document.

However, I can still extract information based on the type of "acceptance criteria" and "study" described in the document, which are regulatory compliance focused.

Here's a breakdown of the requested information based on the provided text:


1. Table of Acceptance Criteria and the Reported Device Performance

For this device, the "acceptance criteria" are compliance with established international standards for medical electrical equipment and software. The "reported device performance" indicates that the device met these standards.

Acceptance Criteria CategorySpecific Acceptance Criteria (Standard/Guidance)Reported Device Performance
EMC and Electrical SafetyIEC 60601-1-2:2014 (Electromagnetic disturbances)Device complies with the standard.
IEC 60601-1:2005 (Basic safety and essential performance)Device complies with the standard.
IEC 60601-2-10:2012 (Nerve and muscle stimulators)Device complies with the standard.
BiocompatibilityISO 10993-5:2009 (Tests for in vitro cytotoxicity)Evaluation conducted according to the standard.
ISO 10993-10:2010 (Tests for irritation and skin sensitization)Evaluation conducted according to the standard.
Software V&VFDA's "Guidance for the Content of Premarket Submissions for Software Contained in Medical Devices" (for "MODERATE" level of concern software)Software verification and validation testing were conducted and documentation provided as recommended.

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

This information is not provided in the document. The document describes compliance testing for electrical safety, EMC, biocompatibility, and software V&V, which typically involve laboratory tests on devices and materials, not clinical "test sets" with patient data in the way an AI/ML diagnostic device would.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

This information is not applicable for the type of testing described (regulatory compliance for an external functional electrical stimulator). Ground truth, in the context of AI/ML, refers to clinically validated diagnoses or outcomes, which are not part of this submission's performance data.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

This information is not applicable for the type of testing described.

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

An MRMC study was not done. This type of study is relevant for AI-assisted diagnostic or interpretive devices. The XFT-2001D is an external functional electrical stimulator, not an interpretive AI device.

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

A standalone performance study of an algorithm (in the context of AI/ML) was not done. The software V&V was conducted for the device's operational software at a "MODERATE" level of concern, indicating its impact on device function rather than a diagnostic performance.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

For the specific performance data presented (EMC, electrical safety, biocompatibility, software V&V), the "ground truth" is defined by the standards themselves. For example, a device's electrical leakage current measurement must be below a certain threshold specified in IEC 60601-1. There isn't "ground truth" derived from patient outcomes or expert consensus in the way it's understood for AI/ML diagnostic tools.

8. The sample size for the training set

This information is not applicable as the device is not an AI/ML-driven diagnostic or predictive model in the context of the provided document. The software mentioned is for the device's operational control, not for "training" algorithms.

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

This information is not applicable as there is no "training set" in the context of an AI/ML model for this device's submission.

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Image /page/0/Picture/0 description: The image contains the logos of the U.S. Department of Health & Human Services and the U.S. Food & Drug Administration (FDA). The Department of Health & Human Services logo is on the left, and the FDA logo is on the right. The FDA logo includes the text "FDA U.S. FOOD & DRUG ADMINISTRATION" in blue.

November 30, 2017

Shenzhen XFT Medical Limited Mrs. Jiang Xiaoying Manager RM 203, BLD1, 14 Jinhui Road, New District Shenzhen, Guangdong CN

Re: K162718

Trade/Device Name: Foot Drop System, Model 2001-D Regulation Number: 21 CFR 882.5810 Regulation Name: External Functional Neuromuscular Stimulator Regulatory Class: Class II Product Code: GZI Dated: October 27, 2017 Received: October 31, 2017

Dear Mrs. Xiaoying:

We have reviewed vour Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food. Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code 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 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

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801); medical device reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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 http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). 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 (http://www.fda.gov/DICE) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely.

Vivek J. Pinto -S

for Carlos L. Peña, PhD, MS Director Division of Neurological and Physical Medicine Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K162718

Device Name Foot Drop System (Model XFT-2001D)

Indications for Use (Describe)

XFT-2001D Foot Drop System is intended to address the lack of ankle dorsiflexion in patients who have sustained damage to upper motor neurons or pathways to the spinal cord. During the swing phase of walking, the XFT-2001D electrically stimulates the appropriate muscles that cause ankle dorsiflexion and may thus improve the individual's gait. Medical benefits of Functional Stimulation (FES) may include prevention/retardation of disuse attophy, increased local blood flow, muscle re-education, and maintained or increased joint range of motion.

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

In accordance with 21 CFR 807.92 the following summary of information is provided:

Date:November 30, 2017
Submitter:Shenzhen XFT Medical LimitedRoom203, Building 1, Biomedicine Innovations Industrial Park,#14 Jinhui Road, Pingshan New District, Shenzhen, China
Contact Person:Mrs. Jiang Xiaoying

Co xfthr3@xft.cn Tel: +86-(0) 755-29888818

Device: Trade Name: Foot Drop System

Model: XFT-2001D series

External Neuromuscular Functional Stimulator Classification Names:

Product Code: GZI Regulation Number: 21 CFR 882.5810 Device Class: Class II Submission Purpose: New Device Predicate Device(s): K123972

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  • Nerve and Muscle Stimulator (Foot Drop System) is a battery-operated, Device
    Description: electrical stimulator that can be used for functional electrical stimulation (FES).

Nerve and Muscle Stimulator (Foot Drop System) is an external functional electrical stimulator. It is a small device that attaches to the leg just below the knee, near the head of the fibula. During a gait cycle, Nerve and Muscle Stimulator (Foot Drop System) stimulates the common peroneal nerve, which innervates the tibialis anterior and other muscles that cause dorsiflexion of the ankle. The Nerve and Muscle Stimulator (Foot Drop System) consists of the Patient Kit and the Clinician Kit. The Patient Kit comprises of all the components and accessories that the patient will take home and use. The Clinician System includes the Medical Records Management Software.

  • Intended Use: XFT-2001D Foot Drop System is intended to address the lack of ankle dorsiflexion in patients who have sustained damage to upper motor neurons or pathways to the spinal cord. During the swing phase of walking, the XFT-2001D electrically stimulates the appropriate muscles that cause ankle dorsiflexion and may thus improve the individual's gait. Medical benefits of Functional Electrical Stimulation (FES) may include prevention/retardation of disuse atrophy, increased local blood flow, muscle re-education, and maintained or increased joint range of motion.
    • Technology: Proposed device and predicate device use a small electrical signal to stimulate the nerves in the leg, causing the muscles contract and produce a movement that can help walking. The most common use of FES is as a treatment for foot drop where disruptions in the nerve pathways between the legs and brain which means the front of your foot cannot be lifted to the correct angle when walking.

The Foot Drop System employs the same fundamental scientific technology as its predicate devices.

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Basis for Technological characteristics, features, specifications, materials and Substantial intended uses of the new device are substantially equivalent to the Equivalence: quoted predicated device. The parameters such as waveform, frequency, pulse width, output current and voltage, although not exactly identical to this particular predicate, do not raise any new questions of safety or effectiveness. Applicable performance and safety testing was performed to verify technological and functional characteristics including any design modification. The differences that exist between the devices are insignificant in terms of safety and effectiveness.

The proposed device is Substantially Equivalent (SE) to the predicate device which is US legally market device. Therefore, the subject device is determined as safe and effectiveness.

Table 1 Comparison between XFT-2001D and the predicate device

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SpecificationPredicate DeviceProposed device
K numberK123972K162718
Device nameWalkAideXFT-2001D
ManufacturerInnovative Neurotronics, Inc.Shenzhen XFT Medical Limited
Intended Use/ Indications forUseThe Innovative Neurotronics WalkAideSystem is intended to address the lack ofankle dorsiflexion in patients who havesustained damage to upper motorneurons or pathways to the spinal cord.During the swing phase of gait, theWalkAide electrically stimulates theappropriate muscles that cause ankledorsiflexion and may thus improve thepatient's gait. Medical benefits ofFunctional Electrical Stimulation (FES)may include prevention/retardation ofdisuse atrophy, increased local bloodflow, muscle re-education, andmaintained or increased joint range ofmotion.XFT-2001D Foot Drop System isintended to address the lack of ankledorsiflexion in patients who havesustained damage to upper motorneurons or pathways to the spinalcord. During the swing phase ofwalking, the XFT-2001D electricallystimulates the appropriate musclesthat cause ankle dorsiflexion and maythus improve the individual's gait.Medical benefits of FunctionalElectrical Stimulation (FES) may includeprevention/retardation of disuseatrophy, increased local blood flow,muscle re-education, and maintainedor increased joint range of motion.
ContraindicationsDo not use on persons with implanteddemand type cardiac pacemakers ordefibrillators.Do not use on persons with implanteddemand type cardiac pacemakers ordefibrillators
Do not place the electrodes in thecarotid sinus region (throat).Do not place the electrodes in thecarotid Sinus region (throat).
Laryngeal or pharyngeal spasms placedacross the throat or in the mouth.Laryngeal or pharyngeal spasms mayoccur when the electrodes are placedacross the throat or in the mouth.
Do not place the electrodes overmalignant tumors.Do not place the electrodes overmalignant tumors.
Do not place the electrodes over areas inwhich symptoms of existing thrombosisare present.Do not place the electrodes over areasin which symptoms of existingthrombosis are present.
Do not use if person has a history ofseizure disorder.Do not use if person has a history ofseizure disorder.
Patient PopulationAdultAdult
Power Source(s)1.5 AA Battery (not rechargeable)DC3.7V, 400mAh, rechargeable lithiumbattery (Stim Unit & Remote control)
Patient Leakage Current-Normal condition: 0.5mA-Normal condition: 0.5mA
SpecificationPredicate DeviceProposed Device
Number of Output Modes2 modes: gait mode and trainingmode2 modes: gait mode and trainingmode
Number of Output Channels11
Regulated Current orRegulated VoltageVoltageCurrent
Software/Firmware/MicroprocessorMicroprocessorMicroprocessor
Auto Overload Trip?NoNo
Auto No-Load Trip?NoYes
Auto Shut Off?NoYes
Patient Override Control?YesYes
Indicator Display
On/Off Status?YesYes
Low Battery?Voltage/Current Level?YesYes
Timer Range (minutes)30 minutes20 minutes
ON Time (seconds)1-5 sec in 1 sec steps1-5 sec in 0.5 sec steps
OFF Time (seconds)1-10 sec in 1 sec steps2-10 sec in 1 sec steps
Net Charge (µC per pulse)16.7-33Hz16.7-33Hz
25-300 microseconds100-300 μS
Frequency (Pulses per second)Pules width adjustable in followingdiscrete steps:25/50/100/150/200/250/300μSPules width adjustable in followingdiscretesteps:100/150/200/250/300uS
Pulse width25-300 microseconds100-300 μS
Pules width adjustable in followingdiscrete steps:25/50/100/150/200/250/300μSPules width adjustable in followingdiscrete steps:100/150/200/250/300uS
41.2µC @ 500 ohm27.0μC @ 500 ohm
Max Phase Charge(μC)28µC @ 1K ohm27.0µC @ 1K ohm
Max Current Density,(mA/cm²)1.8mA/cm² (500 ohm)0.7mA/cm² (500 ohm)
Maximum Power Density,(W/cm²)0.0128W/cm² (500 ohm)0.005W/cm² (500 ohm)
SpecificationPredicate DeviceProposed Device
Max Output Voltageunknown@ 500 ohm45V @ 500 ohm
121V@ 1 K ohm90V @ 1 K ohm
unknown @ 2 K ohm156V @ 2 K ohm
unknown @ 10 K ohm158V@ 10 K ohm
Max Output Current20.7mA rms@ 500 ohm14mA rms@ 500 ohm
unknown @ 2 K ohm11mA rms@ 2 K ohm
unknown @ 10 K ohm2.2mA rms@10 K ohm
Burst Mode
-Pulses per burstBurst length and PPS dependentBurst length and PPS dependent
-Bursts per secondDepends on ON and OFF timesDepends on ON and OFF times
-Burst duration(seconds)-Duty Cycle [Line (b) x Line (c)]1 to 5 sec in 1 sec steps Depends onON and OFF times1 to 5 sec in 1 sec steps Depends onON and OFF times
Stimulation Trigger SourceTilt Sensor or Foot SensorTilt Sensor
Anatomical SitesLimbLimb
Shipping and storageTemp: -20 °C to 60 °CRelative Humidity: 95% max, non-condensingtemp: -20°C to 55°C RelativeHumidity< 93%Atmos.: 700-1060hPa
Operating ConditionsTemp: 0-40 degrees CAltitude: from -400 to 2,400 meters(- 1300 to 8,000 ft)temp: -5°C to 40°C RelativeHumidity< 80%Atmos.: 860-1060hPa
Relative Humidity: 0 to 95%, non-condensing
Electrode Size and Shape3.175 cm (1.25 inches) diameterRound5 cm diameter Round
Electrode materials(Basicmechanical element) Materialcontacting skinHydrogel and Stainless Steel (SS)316Hydrogel /conductive fabric
Materials-cufffabricfabric
SpecificationPredicate DeviceProposed Device
MaximumStimulation Period3 seconds3 seconds
Wireless communicationBlue tooth 1.2Blue tooth 4.0
Weight87.9 g43 g
Dimensions (in.) [W x H x D]826121mm737010mm
Housing Materials andConstructionABSABS
WaveformAsymmetrical BiphasicAsymmetrical Biphasic
Shaperectangularrectangular
Expected Service Life5 years5 years
Compliance with 21CFR 898?YesYes
Compliance with VoluntaryStandardsIEC 60601-1IEC 60601-1-2IEC 60601-2-10IEC 60601-1IEC 60601-1-2IEC 60601-2-10

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Performance The following performance data were provided in support of the substantial

Data: equivalence determination.

EMC and Electrical safety

Electrical safety and EMC testing were conducted on the XFT-2001D (clinical kit), consisting of a Cuff, a Functional Stimulation Unit, and a Remote Control.

The device complies with IEC 60601-1-2:2014: Medical electrical equipment

-Part 1-2: General requirements for basic safety and essential performance -Collateral Standard: Electromagnetic disturbances - Requirements and tests. IEC 60601-1:2005 ( Third Edition)+CORR.1:2006+CORR.2:2007+A1:2012 Consolidated version Medical electrical equipment -Part 1: General requirements for basic safety and essential performance.

IEC 60601-2-10:2012 Medical electrical equipment -Part 2-10: Particular requirements for the basic safety and essential performance of nerve and muscle stimulators.

Biocompatibility

The electrode pads are the mainly body contacting parts. Electrode pads, as accessories of the device, are adopted the Self-adhesive Electrode manufactured by Top Rank Health Care Equipment Co., Ltd and have been cleared by FDA in November 22, 2013 as K132588.The electrode pads is considered skin contacting for a duration of less than 24 hours.

The biocompatibility evaluation for the XFT-2001D cuff was conducted in accordance with ISO 10993-5:2009 Biological evaluation of medical devices

-- Part 5: Tests for in vitro cytotoxicity and ISO 10993-10:2010 Biological evaluation of medical devices -- Part 10: Tests for irritation and skin sensitization.

Software Verification and Validation

The software for this device was considered as a "MODERATE" level of concern, the software failure or design flaw prior to mitigation may lead to an error in the intensity or timing of stimulation that could result in minor injury such as skin irritation to the patient. And software verification and validation testing were conducted and documentation was provided as recommended by FDA's Guidance for Industry and FDA Staff, "Guidance for the Content of Premarket Submissions for Software Contained in Medical Devices."

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  • Shenzhen XFT Medical Limited believes that the XFT-2001D Foot Drop Conclusion: System is as safe and effective, and performs in a substantially equivalent manner to the predicate device. The modifications do not raise any safety or effectiveness issues and meet the applicable requirements of IEC60601-2- 10 "Particular requirements for the safety of nerve and muscle stimulators." and the FDA document "Guidance Document for Powered Muscle Stimulator 510(k)s" June 9, 1999. We conclude that the proposed XFT- 2001D Foot Drop System is substantially equivalent to the WalkAide System (K123972).

§ 882.5810 External functional neuromuscular stimulator.

(a)
Identification. An external functional neuromuscular stimulator is an electrical stimulator that uses external electrodes for stimulating muscles in the leg and ankle of partially paralyzed patients (e.g., after stroke) to provide flexion of the foot and thus improve the patient's gait.(b)
Classification. Class II (performance standards).