(123 days)
The Innovative Neurotronics WalkAide External Neuromuscular Stimulator (WalkAide 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 gait, the WalkAide System electrically stimulates the appropriate muscles that cause ankle dorsiflexion and may thus improve the gait in patients with chronic stroke. Medical benefits of Functional Electrical Stimulation (FES) may include prevention of disuse atrophy, increased local blood flow, muscle reeducation, and maintained or increased joint range of motion.
The WalkAide 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, the WalkAide stimulates the common peroneal nerve, which innervates the tibialis anterior and other muscles that cause dorsiflexion of the ankle. The WalkAide System consists of the WalkAide Patient Kit and the WalkAide Clinician Kit. The WalkAide Patient Kit comprises of all the components and accessories that the patient will take home and use. The Clinician System comprises the accessories that a clinician (i.e., orthotic specialist, physiotherapist, occupational therapist, etc.) will use to set up a patient's WalkAide.
Here's an analysis of the acceptance criteria and study information based on the provided document:
Acceptance Criteria and Device Performance
The document describes the WalkAide System and primarily focuses on extending its "Indications for Use" to specifically include chronic stroke patients for improved gait. Given that the device itself (hardware and software) is stated to be "identical to the predicate K123972" except for this indication, the acceptance criteria here are implicitly tied to demonstrating the device's effectiveness and safety for this expanded indication compared to a standard treatment.
The document doesn't present a specific table of quantitative acceptance criteria from the FDA for a new device, but rather a Comparison Conclusion Table (on pages 16-17) that highlights the identity of the current device to its predicate (K123972) in terms of technical specifications. The key acceptance is based on the clinical study supporting the new indication.
Implicit Acceptance Criteria (for the new indication) and Reported Device Performance:
| Acceptance Criteria Category (Implicit) | Reported Device Performance (from the study) |
|---|---|
| Effectiveness for Gait Improvement in Chronic Stroke: The device should demonstrate improvement in gait velocity and overall quality of gait in chronic stroke patients. | "The results of this study show the WA to be equivalent to the AFO for improvements in gait velocity..." "The WA produces physiological dorsiflexion, with all the motor and sensory benefits inherent in active muscle contraction, including improved gait speed and improved overall quality of gait for individuals poststroke." |
| Equivalence to Standard of Care (AFO): The device should perform at least as well as the Ankle-Foot Orthosis (AFO) in relevant clinical outcomes for this population. | "...the WA to be equivalent to the AFO for improvements in gait velocity, SIS composite score and safety." |
| Safety in Chronic Stroke Population: The introduction of the device for this population should not introduce new safety concerns compared to the AFO. | "...equivalent to the AFO for improvements in gait velocity, SIS composite score and safety." |
| Functional Improvements: The device should lead to clinically relevant functional ambulation improvements. | "Results from this study support the fact that use of the WA produces clinically relevant in functional ambulation..." |
| Applicability to Chronic Phase: Improvements should be observable even in the chronic phase of stroke. | "...these results were reported in a population of individuals averaging 6.9 years from onset of stroke, this study demonstrates that functional improvements can be obtained in the chronic phase of stroke..." |
Study Information:
-
Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample Size: The exact sample size is not explicitly stated in the provided document. It only mentions "a randomized trial utilized an unblinded, parallel group design."
- Data Provenance: The document does not specify the country of origin. The study was a "randomized trial," which suggests it was prospective. Data analysis used "an intention to treat analysis with missing data points calculated using multiple imputations."
-
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 provided in the document. The study compared the device (WA) to an Ankle-Foot Orthosis (AFO) and measured "gait velocity, SIS composite score and safety." These seem to be objective and standardized outcome measures, rather than requiring subjective expert ground truth establishment for the test set.
-
Adjudication method (e.g. 2+1, 3+1, none) for the test set
- This information is not provided in the document. Given the outcome measures (gait velocity, SIS score, safety), it's unlikely that an adjudication method for image interpretation or diagnosis was required.
-
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, this was not an MRMC comparative effectiveness study involving human readers and AI assistance. This was a clinical trial comparing a medical device (WalkAide) against a conventional treatment (AFO) in patients. The document does not mention human readers or AI assistance in the context of interpretation.
-
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- No. The WalkAide System is a functional electrical stimulator used by patients with setup and monitoring by a clinician. It is a human-in-the-loop device. The study itself was a clinical trial assessing patient outcomes with the device.
-
The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- The "ground truth" for evaluating the device's effectiveness was based on clinical outcomes data, specifically:
- Gait velocity
- SIS composite score (Stroke Impact Scale or similar, implying a functional assessment)
- Safety data
- The "ground truth" for evaluating the device's effectiveness was based on clinical outcomes data, specifically:
-
The sample size for the training set
- This information is not applicable and therefore not provided. The WalkAide system is a hardware device (functional electrical stimulator) with accompanying software for configuration and analysis. It is not an AI/ML algorithm that is trained on a dataset in the typical sense. The study was a clinical trial to demonstrate effectiveness for an indication, not to train or validate an algorithm.
-
How the ground truth for the training set was established
- This information is not applicable for the reasons stated above. The device doesn't have a "training set" in the context of artificial intelligence. Its functionality is based on established principles of electrical stimulation and biomechanics. Its performance is validated through clinical trials.
{0}------------------------------------------------
Image /page/0/Picture/1 description: The image is a black and white logo for the U.S. Department of Health and Human Services. The logo features a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the seal is a stylized image of three human profiles facing right, with flowing lines representing hair or fabric. To the right of the seal, the letters "DE" are visible, suggesting the full word "DEPARTMENT" was intended.
Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
August 8, 2014
Innovative Neurotronics, Inc. c/o Mr. Glen Neally 3600 North Capital of Texas Highway Building B. Suite 150 Austin, Texas 78746
Re: K140886
Trade Name: WalkAide System Regulation Number: 21 CFR 882.5810 Regulation Name: External functional neuromuscular stimulator Regulatory Class: Class II Product Code: GZI Dated: May 5, 2014 Received: May 13, 2014
Dear Mr. Neally:
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. The general controls provisions of the Act include requirements for annual registration. Isting 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 801); medical device reporting (reporting of medical
{1}------------------------------------------------
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.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR 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.
You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.
Sincerely yours,
Felipe Aguel -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
{2}------------------------------------------------
Indications for Use
510(k) Number (if known) K140886
Device Name WalkAide System
Indications for Use (Describe)
The Innovative Neurotronics WalkAide External Neuromuscular Stimulator (WalkAide 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 gait, the WalkAide System electrically stimulates the appropriate muscles that cause ankle dorsiflexion and may thus improve the gait in patients with chronic stroke. Medical benefits of Functional Electrical Stimulation (FES) may include prevention of disuse atrophy, increased local blood flow, muscle reeducation, and maintained or increased joint range of motion.
Type of Use (Select one or both, as applicable)
2 Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)
PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON A SEPARATE PAGE IF NEEDED.
FOR FDA USE ONLY
Concurrence of Center for Devices and Radiological Health (CDRH) (Signature)
This section applies only to requirements of the Paperwork Reduction Act of 1995.
DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.
The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:
Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff(@fda.hhs.gov
"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."
{3}------------------------------------------------
510(k) Summary for the Innovative Neurotronics, Inc. WalkAide System
1. SPONSOR
Innovative Neurotronics, Inc. 3600 N. Capital of Texas Highway Bldg. B. Suite 150 Austin, Texas 87846
| Contact Person: Glen Neally – Director of Quality and Regulatory | |
|---|---|
| Telephone: | 1-512-721-1903 |
| Fax: | 1-512-721-1939 |
May 5, 2014 Date Prepared:
2. DEVICE NAME
| Proprietary Name: | WalkAide |
|---|---|
| Common/Usual Name: | External Neuromuscular Functional Stimulator |
| Classification Names: | External Neuromuscular Functional Stimulator |
| Classification Number: 21 CFR 882.5810 | |
| Product Code: | GZI |
-
- PREDICATE DEVICES WalkAide System- K123972
4. INTENDED USE
The Innovative Neurotronics WalkAide External Functional Neuromuscular Stimulator (WalkAide 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 gait, the WalkAide System electrically stimulates the appropriate muscles that cause ankle dorsiflexion and may thus improve the gait in patients with chronic stroke. 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.
{4}------------------------------------------------
5. DEVICE DESCRIPTION
The WalkAide 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, the WalkAide stimulates the common peroneal nerve, which innervates the tibialis anterior and other muscles that cause dorsiflexion of the ankle. The WalkAide System consists of the WalkAide Patient Kit and the WalkAide Clinician Kit . The WalkAide Patient Kit comprises of all the components and accessories that the patient will take home and use. The Clinician System comprises the accessories that a clinician (i.e., orthotic specialist, physiotherapist, occupational therapist, etc.) will use to set up a patient's WalkAide.
WalkAide Patient Kit
The WalkAide Patient Kit consists of the components and accessories that the patient takes home. The WalkAide Patient Kit includes (See Fig 4.1):
- WalkAide Control Module (Stimulator Unit) ●
- WalkAide Leg Cuff ●
- WalkAide Electrode Cable ●
- Electrodes (ordered seperately) ●
- Foot Sensor (Optional) .
Image /page/4/Picture/9 description: The image shows a medical device with a gray and black design. The device has a control panel with a blue knob and two white buttons. A gray cable is connected to the device, and a tan-colored sensor with a black wire is also visible. The device appears to be used for medical monitoring or treatment.
{5}------------------------------------------------
Image /page/5/Picture/0 description: The image shows a collection of medical devices and accessories. There is a foot sensor template with cutting guidelines and size markings. Additionally, there are two circular electrode pads with attached wires, a beige-colored adjustable strap, a device with a blue knob, and various connecting cables with red and black connectors.
WalkAide Patient Kit
WalkAide Control Module (WalkAide)
As with the parent K123972 WalkAide control module, the Innovative Neurotronics WalkAide Control Module houses the electronics and controls of the WalkAide system, and delivers electrical stimulation to the end-user's peroneal nerve via surface electrodes. The WalkAide attaches to the Leg Cuff and provides the stimulation pulse to the electrodes. The WalkAide requires a single AA battery to operate.
{6}------------------------------------------------
Image /page/6/Picture/0 description: The image shows a person's leg with a medical device attached to the upper part of the leg. The device is attached with a strap. The leg is shown from the thigh to the foot. The person's toes are visible.
WalkAide attached to WalkAide Cuff on a Patient's Leg
As with the K123972 WalkAide, the Innovative Neurotronics WalkAide is a microprocessor controlled device, and uses an EEPROM to store device, user, and configuration information. The intensity is controlled by the potentiometer on the top face of the WalkAide control module. The position of the potentiometer controls the appropriate stimulation intensity.
Stimulation could be triggered by three mechanisms: the Tilt Sensor inside the control module, a Foot Sensor or Heel Sensor, or through the Hand Switch (the WalkLink.) Three LEDs (green, amber, and red) provide indications such as start up, stimulation, low battery, and fault. Additional information about these indicators is provided in the User Manual in Appendix A-2.
WalkAide Bi-Flex Cuff
The WalkAide is designed for single-handed application and removal. It may take a bit of practice to develop a routine that works best for each person. The WalkAide is applied directly to the leg and can be easily worn under most clothing. The clinician will find the optimal placement of the electrodes on the initial visit. The electrode placement will be marked on
{7}------------------------------------------------
the inside of the cuff via Red and Black Electrode Locators and the position should not be moved by the patient.
Image /page/7/Picture/1 description: The image shows two different views of a medical device. The device appears to be a head-mounted apparatus with a gray frame and black straps. The top image shows the device from a side angle, revealing a padded interior with circular openings and a control panel with a blue knob. The bottom image shows the underside of the device, highlighting the frame's structure and the attachment points for the straps.
WalkAide Cuff
Electrodes
As with the K123972 Walk-Aide, the Innovative Neurotronics WalkAide System uses two surface electrodes. The WalkAide electrodes consist of electrodes that have been cleared under 510(k) (currently numbers K872976, K962332, K070807).
{8}------------------------------------------------
Image /page/8/Figure/0 description: This image shows a technical drawing of an object with various dimensions and labels. On the left, a circular object labeled "1" has a diameter of 1.25 inches (32mm) and a height of 0.75 inches (19mm). The total height of the object, including the handle labeled "2", is 3.50 +/- 0.25 inches (89mm). The right side of the image shows a side view of the object with labels 1A, 1B, 1C, 2A, 2B, 2C, and 2D.
WalkAide Electrodes
Electrode Cable
This is a Y connector cable for connecting the electrodes with WalkAide. One end is connected to the connector slot on the back of the electrode, and the other two ends (black and red) are connected to respective electrodes.
Image /page/8/Figure/4 description: The image shows a Y-splitter cable with two female connectors on one end and a male connector on the other end. The two female connectors are identical and have a cylindrical shape with a hollow center. The male connector is right-angled and has a cylindrical shape with a pin in the center. The cable is white and has a smooth surface.
WalkAide Electrode Cable
{9}------------------------------------------------
Foot Sensor (Optional Item)
The Foot Sensor is the same as in the parent WalkAide system. No changes have been made to the foot sensor. The Foot Sensor is designed for those individuals whose leg movement is limited such that the Tilt Sensor cannot be adequately used. The Foot Sensor is based on a force sensor resistor (FSR) as the detection element. The Foot Sensor plugs into the receptacle on the side of the WalkAide control module as it did in the parent device.
Image /page/9/Picture/2 description: The image shows a line drawing of a heated insole with a cord and plug. The insole is shaped like a foot and has several layers. The cord is attached to the insole and has a plug at the end. The plug is a standard 3.5mm audio plug. The insole is likely used to keep feet warm in cold weather.
Foot Sensor
WalkAide Clinician Kit
The WalkAide Clinician Kit, which is similar to the Clinician System used in the parent WalkAide, is used by trained professionals (clinicians) in a clinical setting to configure WalkAide for an individual user. The WalkAide Clinician Kit is only used by the clinician and it is not sent with the patient.
Innovative Neurotronics uses the WalkAide Clinician System Software called the WalkAnalyst, with Notebook/Tablet PC/Desktop platform for the ease of use and better display. The Notebook/Tablet PC/Desktop is not provided by Innovative Neurotronics. The WalkAnalyst has been developed and validated according to regulatory guidance documents.
The WalkAide consists of the following components:
- WalkAnalyst Software ●
- WalkLink (Hand Switch)
- Heel Sensor
{10}------------------------------------------------
Image /page/10/Picture/0 description: The image shows a white box with a black lanyard attached to the top. There is a black cord coming out of the bottom of the box. To the left of the box is a gray cord with a plug on the end and a tan-colored object. To the right of the box is a black cord.
Clinician Kit without WalkAnalyst Software
WalkAnalyst Software
The WalkAnalyst software has been developed exclusively for the proposed Innovative Neurotronics WalkAide. This software can be installed on a Tablet PC, notebook, or desktop PC hardware platform. The WalkAnalyst performs the following functions:
- Set up configuration of WalkAide Control Module, which includes management of data input from tilt sensor, and heel/foot sensor
- Management of patient information ●
- . Graphical display of stimulation information and gait recordings
- Analysis of data and optimization of stimulation parameters
- Report generation .
The WalkAnalyst software communicates with WalkAide via a Bluetooth wireless communication device in the WalkLink.
WalkLink (Hand Switch)
The WalkLink is only used during the patient set-up and control module configuration process. The WalkLink serves two purposes (1) the
{11}------------------------------------------------
Clinician can stimulate the patient at the appropriate times during the setup process (2) It communicate gait recording from WalkAide to the PC (Tablet/Notebook/Desktop) using Bluetooth (BT) wireless communication protocol. It should be noted that WalkAide itself does not have Bluetooth functionalities. WalkAide communicates with WalkLink using the WalkLink cable. WalkLink transmits the information received from WalkAide to the PC using the Bluetooth protocol.
The WalkLink contains a stimulation button and three LED indicators. The green blinking indicator shows adequate battery voltage, the red indicator indicates low battery or error, and the blue blinking indicator indicates that BT link is established.
Image /page/11/Picture/2 description: The image shows two devices, one is a slim device with a pairing button, and the other is a WalkLink device. The WalkLink device has a logo at the top and three lights, one green, one red, and one blue. The device also has an FC label and the text "Tested to comply with FCC standards".
WalkLink
WalkLink Cable
The WalkLink cable connects WalkLink with WalkAide. This cable contains standard RS232 communication lines. This is a 5 conductor stranded cable approximately 40 inches long cable.
Image /page/11/Figure/6 description: The image shows a drawing of a flexible endoscope. The endoscope is a long, thin tube with a camera and light at the end. It is used to view the inside of the body. The endoscope in the image has a curved shape. The endoscope has a connector at each end.
{12}------------------------------------------------
WalkAide to WalkLink Cable
Heel Sensor
The heel sensor is the same patient heel sensor used in the parent WalkAide system. No changes have been made to the Heel Sensor. The design is similar to the Foot Sensor, as it incorporates a force sensitive sensor (FSR) as the detection element. The Heel Sensor is intended for use in the clinic by the Clinician during the device set-up stage.
Fig 4.10: Heel Sensor
4.5 Operations and Set-up of the WalkAide System
The operation and set-up of the WalkAide system is detailed in the Clinician Manual. The following is a summary:
The patient places the back electrode slightly posterior and distal to the head of the fibula and the front electrode on the upper 1/3 of the tibialis anterior muscle over the muscle belly. The back electrode is connected to the black lead and the front electrode to the red lead. The WalkAide is turned on by rotating the intensity control on the Control Module. The round intensity knob is moved counter-clockwise through "0" or in the direction of increasing numbers. The STIM button labeled (J) is depressed for 1 to 2 seconds to provide a test stimulus. An amber light on the top of the
{13}------------------------------------------------
WalkAide Control Module indicates that the unit is stimulating. If the ankle movement produced by the stimulus is too small, the intensity control is turned up or the black electrode is adjusted slightly to the rear, then application of the test stimulus is attempted again. Stimulation consists of delivering a train of biphasic current pulses to the common peroneal nerve via two surface electrodes. The goal is to produce a relatively pure dorsiflexion of the ankle with as low stimulus intensity as possible. Once the optimal electrode positions have been found, the cuff is placed over the electrodes.
The cuff is then removed with the electrodes that are affixed by Velcro to the inside of the cuff. The Clinician then positions the electrodes on the leg cuff for patient reference during future electrode replacement. The leads from the electrodes are threaded through the holes on the cuff. The black lead of the Y-connector cable is connected to the back electrode and the red to the anterior electrode. The electrodes, leads and connectors are placed in the groove or pocket of the cuff and covered with a Velcro strap. A heel sensor is placed in the patient's shoe on the affected side and is connected to the WalkAide Control Module. As with the parent Walk-Aide, the WalkAide Control Module houses the electronics and controls of the WalkAide, and delivers electrical stimulation to the patient via two surface electrodes.
The Clinician collects and analysis gait recording by using WalkAnalyst Software and according to set-up shown in Fig 4.11. After optimal parameters are selected, WalkAide is configured using the selected parameters.
{14}------------------------------------------------
Image /page/14/Figure/0 description: The image shows a diagram of a clinician using a WalkLink device to apply manual stimulation to a patient. The patient is wearing a heel sensor in their shoe, and they are walking in a figure-eight pattern with a WalkAide device. The WalkAide is connected to the WalkLink, and a tablet PC, notebook, or desktop computer is collecting heel sensor and stimulation data for the clinician using WalkAnalyst. The diagram is labeled with the numbers 1-4, which correspond to the different steps in the process.
Fig 4.11: WalkAide Set-up Process
Once set up and configuration has been completed by the Clinician, WalkLink is disconnected from the WalkAide. WalkAide, including the accessories such as the WalkAide Cuff, Electrodes, Electrode Cable, and Foot Sensor (optional item) is provided to the patient.
WalkAide in normal operation mode will use the Tilt Sensor or optional Foot Sensor to sense the appropriate point in the patient's gait (walk) cycle to trigger stimulation. The WalkAide provides visual and audible indications for various conditions such as operational status and low battery condition.
{15}------------------------------------------------
6. BASIS FOR SUBSTANTIAL EQUIVALENCE
The purpose of this 510(k) is to update the submission of the Walk-Aide System (K123972) to include in the Indications For Use Summary Statement the specific population of chronic stroke patients for the specific indication of improved gait. This is the only change in this submission.
Clinical data is submitted to support the difference in indication for use. The randomized trial utilized an unblinded, parallel group design. The purpose of this study was to compare of the WalkAide Functional Electrical Stimulation device (WA) versus an Ankle-Foot Orthosis (AFO) in subjects with chronic stroke. Subjects were required to be at least 6 months post stroke. The study data was analyzed using an intention to treat analysis with missing data points calculated using multiple imputations. The clinical trial data outcomes support chronic stroke population for gait improvement.
Comparison Conclusion Table:
{16}------------------------------------------------
| FEATURE | INNOVATIVENEUROTRONICS, INC.WALKAIDECurrent Submission | INNOVATIVENEUROTRONICS, INC.WALKAIDEK123972 | COMPARISON |
|---|---|---|---|
| Intended Use | SUMMARY STATEMENTThe Innovative NeurotronicsWalkAide External FunctionalNeuromuscular Stimulator(WalkAide System) is intendedto address the lack of ankledorsiflexion in patients who havesustained damage to upper motorneurons or pathways to the spinalcord. During the swing phase ofgait, the WalkAide Systemelectrically stimulates theappropriate muscles that causeankle dorsiflexion and may thusimprove the gait in patients withchronic stroke. Medical benefitsof Functional ElectricalStimulation (FES) may includeprevention/ retardation of disuseatrophy, increased local bloodflow, muscle re-education, andmaintained or increased jointrange of motion. | SUMMARY STATEMENTThe Innovative NeurotronicsWalkAide External FunctionalNeuromuscular Stimulator(WalkAide System) is intendedto address the lack of ankledorsiflexion in patients whohave sustained damage toupper motor neurons orpathways to the spinal cord.During the swing phase of gait,the WalkAide Systemelectrically stimulates theappropriate muscles that causeankle dorsiflexion and maythus improve the patient's gait.Medical benefits of FunctionalElectrical Stimulation (FES)may include prevention/retardation of disuse atrophy,increased local blood flow,muscle re-education, andmaintained or increased jointrange of motion. | This currentsubmission hasincluded theindication of gaitimprovement forchronic strokepatients. |
| FEATURE | INNOVATIVENEUROTRONICS, INC.WALKAIDECurrent Submission | INNOVATIVENEUROTRONICS, INC.WALKAIDEK123972 | COMPARISON |
| Power Source | 1.5 V AA Battery(not rechargeable) | 1.5VAABattery(not rechargeable) | Identical |
| Microprocessor Controlled | Yes | Yes | Identical |
| IndicatorsUnit functioningLow Battery | YesYes | YesYes | Identical |
| Patient Device Set-up andTraining | Done by a clinician usinga Notebook/Tablet PC | Done by a clinicianusing a Notebook/TabletPC | Identical |
| Number of Output Modes | 1 | 1 | Identical |
| Channels | 1 | 1 | Identical |
| Output StageTypeRange/AccuracyLoad | Constant Voltage(Adjustable)0 - 110 V (±10%)1000 Ohm load | Constant Voltage(Adjustable)0 - 110 V (±10%)1000 Ohm load | Identical |
| Max Output Current | <208 mA peak @500 Ohm load<121 mA peak @1000 Ohm load | <208 mA peak @500 Ohm load<121 mA peak @1000 Ohm load | Identical |
| Max Output Voltage(baseline to peak; load) | 121 V1000 Ohm load<150 V1M Ohm load | 121 V1000 Ohm load<150 V1M Ohm load | Identical |
| FEATURE | INNOVATIVENEUROTRONICS, INC.WALKAIDECurrent Submission | INNOVATIVENEUROTRONICS, INC.WALKAIDEK123972 | COMPARISON |
| Ramp Modulations (for gait)Ramp UpRamp Down | YesYes | YesYes | Identical |
| WaveformMonophasic or BiphasicSymmetrical orAsymmetrical Shape | BiphasicAsymmetrical | BiphasicAsymmetrical | Identical |
| Pulse Duration | 25-300 microseconds.Accuracy ±5% or ±7microseconds, whicheveris greater. | 25-300 microseconds.Accuracy ±5% or ±7microseconds, whicheveris greater. | Identical |
| Frequency Range(Pulses per second) | 16.7 to 33.3 (Adjustable)pps | 16.7 to 33.3 (Adjustable)pps | Identical |
| Stimulation Trigger Source(When used for gait) | Tilt Sensor or Foot Sensor | Tilt Sensor or FootSensor | Identical |
| Burst DurationStimulation when used forgaitMax. Burst Duration(Seconds) | Dependent on length andspeed of stride5 | Dependent on length andspeed of stride5 | Identical |
| Max Phase Charge:500 Ohms:1K Ohms: | 50 microCoulombs30 microCoulombs | 50 microCoulombs30 microCoulombs | Identical |
| Max. Current Density | 25.3 mA/cm², peak | 25.3 mA/cm², peak | Identical |
| FEATURE | INNOVATIVENEUROTRONICS, INC.WALKAIDECurrent Submission | INNOVATIVENEUROTRONICS, INC.WALKAIDEK123972 | COMPARISON |
| Maximum Average CurrentDensity | 0.25 mA/cm², avg. | 0.25 mA/cm², avg. | Identical |
| Max. Average Power Density | 27.6 mW/cm²(Using 500 Ohm) | 27.6 mW/cm²(Using 500 Ohm) | Identical |
| Electrode Size and Shape(Smallest recommended) | 3.175 cm (1.25 inches)diameterRound | 3.175 cm (1.25 inches)diameterRound | Identical |
| Electrode material(Basic mechanical element) | Hydrogel and StainlessSteel (SS) 316 | Hydrogel and StainlessSteel (SS) 316 | Identical |
| Material contacting skin | |||
| Housing Material | ABS | ABS | Identical |
{17}------------------------------------------------
{18}------------------------------------------------
{19}------------------------------------------------
Non-clinical performance testing summary:
{20}------------------------------------------------
17-11 IEC 60601-2-10 Edition 2.0 2012-06, medical electrical equipment -- part 2-10: particular requirements for the basic safety and essential performance of nerve and muscle stimulators. (Neurology)
19-1
IEC 60601-1-2 Edition 3: 2007-03, medical electrical equipment - part 1-2: general requirements for basic safety and essential performance - collateral standard: electromagnetic compatibility - requirements and tests. (General II (ES/EMC))
19-4
AAMI / ANSI ES60601-1:2005/(R)2012 and A1:2012,, c1:2009/(r)2012 and a2:2010/(r)2012 (consolidated text) medical electrical equipment - part 1: general requirements for basic safety and essential performance (iec 60601-1:2005, mod). (General II (ES/EMC))
- CONCLUSIONS
{21}------------------------------------------------
As indicated in the comparison table above the device and software are identical to the predicate K123972. The only change is in the indications for use, and clinical data has been presented for this.
The results of this study show the WA to be equivalent to the AFO for improvements in gait velocity, SIS composite score and safety. The WA produces physiological dorsiflexion, with all the motor and sensory benefits inherent in active muscle contraction, including improved gait speed and improved overall quality of gait for individuals poststroke. Results from this study support the fact that use of the WA produces clinically relevant in functional ambulation and thus should be considered a viable alternative to conventional bracing for individuals with foot drop secondary to chronic stroke. Because these results were reported in a population of individuals averaging 6.9 years from onset of stroke, this study demonstrates that functional improvements can be obtained in the chronic phase of stroke with appropriate intervention, and that continued recovery of function should remain a goal throughout the lifetime of a person with stroke.
§ 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).