Stim2Go

K230701 · PAJUNK GmbH Medizintechnologie · IPF · Nov 24, 2023 · Physical Medicine

Device Facts

• Record ID: K230701
• Device Name: Stim2Go
• Applicant: PAJUNK GmbH Medizintechnologie
• Product Code: IPF · Physical Medicine
• Decision Date: Nov 24, 2023
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 890.5850
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

As a powered muscle stimulator (NMES) the Stim2Go is indicated for the following conditions: - Relaxation of muscle spasm - Prevention or retardation of disuse atrophy - Increasing local blood circulation - Muscle re-education - Immediate post-surgical stimulation of calf muscles to prevent venous thrombosis - Maintaining or increasing range of motion As a transcutaneous electrical nerve stimulator (TENS) for pain relief the Stim2Go is indicated for the following conditions: - Symptomatic relief and management of chronic (long-term), intractable pain - Adjunctive treatment in the management of post-surgical pain and post traumatic acute pain As a biofeedback device the Stim2Go is indicated for the following condition: - Muscle re-education purposes As a functional neuromuscular stimulator, the Stim2Go is indicated for the following conditions: - Helps to relearn voluntary motor functions of the extremities The movement-based biofeedback can only be used for patients with an active range of motion (ROM) which is defined as the ability of volitional movement resulting in a change of the concerned limb inclination angle of at least 10 degrees.

Device Story

Stim2Go is a portable, hand-held/body-worn electrical stimulation device for neurological patients with motor/sensory impairments. It provides NMES, TENS, and FES. The device uses a built-in inertial sensor (3D gyroscope/accelerometer) to capture real-time limb inclination data. A complementary filter (200 Hz) processes this data to detect volitional movement; when movement exceeds a 10-degree threshold, the device triggers pre-configured electrical stimulation patterns to support motor function. Operated via a smartphone app, it allows therapists to control stimulation parameters. Used in clinical or home settings (with assistance), it helps patients relearn motor functions, manage pain, and prevent atrophy. The output is biphasic symmetrical electrical pulses delivered via electrodes. It benefits patients by providing movement-contingent stimulation, facilitating muscle re-education and functional recovery.

Clinical Evidence

Bench testing only. No clinical trials were conducted. Performance was validated through electrical safety testing (IEC 60601-1, 60601-2-10), battery safety (IEC 62133-2), electromagnetic compatibility (IEC 60601-1-2), and software verification (IEC 62304). Usability/human factors testing (formative and summative) confirmed design suitability for intended users.

Technological Characteristics

Portable, battery-powered (Li-Ion 3.7V) electrical stimulator. Housing: Plastics. Output: Biphasic symmetrical rectangular pulses; regulated current. Sensing: 3D gyroscope/accelerometer inertial sensor. Connectivity: Wireless (Bluetooth) via smartphone app. Sterilization: N/A (non-sterile). Standards: IEC 60601-1, 60601-1-2, 60601-1-6, 60601-1-11, 60601-2-10, IEC 62304, IEC 62133-2.

Indications for Use

Indicated for patients with motor/sensory impairments requiring NMES, TENS, biofeedback, or functional neuromuscular stimulation. NMES/TENS conditions include muscle spasm, disuse atrophy, poor circulation, muscle re-education, post-surgical calf stimulation, ROM maintenance, and chronic/acute pain management. Biofeedback/FES indicated for motor function relearning. Movement-based biofeedback requires active ROM (volitional limb inclination change ≥10 degrees).

Regulatory Classification

Identification

A powered muscle stimulator is an electrically powered device intended for medical purposes that repeatedly contracts muscles by passing electrical currents through electrodes contacting the affected body area.

Predicate Devices

• STIWELL med4 (K080950)

Submission Summary (Full Text)

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November 24, 2023

PAJUNK GmbH Medizintechnologie Christian Quass, Director Regulatory Affairs Karl-Hall-Str. 1 Geisingen, 78187 Germany

Re: K230701

Trade/Device Name: Stim2Go Regulation Number: 21 CFR 890.5850 Regulation Name: Powered Muscle Stimulator Regulatory Class: Class II Product Code: IPF, GZI, GZJ, HCC Dated: March 14, 2023 Received: March 14, 2023

Dear Christian Quass:

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 (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

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Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

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 of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

Sincerely,

# Jitendra V. Virani -S

CDR Jitendra Virani, MS, MBA Assistant Director DHT5B: Division of Neuromodulation and Rehabilitation Devices OHT5: Office of Neurological and Physical Medicine Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health

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## Indications for Use

510(k) Number (if known) K230701

Device Name Stim2Go

Indications for Use (Describe)

As a powered muscle stimulator (NMES) the Stim2Go is indicated for the following conditions:

- · Relaxation of muscle spasm
- · Prevention or retardation of disuse atrophy
- · Increasing local blood circulation
- · Muscle re-education
- · Immediate post-surgical stimulation of calf muscles to prevent venous thrombosis
- · Maintaining or increasing range of motion

As a transcutaneous electrical nerve stimulator (TENS) for pain relief the Stim2Go is indicated for the following conditions:

· Symptomatic relief and management of chronic (long-term), intractable pain

- · Adjunctive treatment in the management of post-surgical pain and post traumatic acute pain
- As a biofeedback device the Stim2Go is indicated for the following condition:
- · Muscle re-education purposes
- As a functional neuromuscular stimulator, the Stim2Go is indicated for the following conditions:
- · Helps to relearn voluntary motor functions of the extremities

The movement-based biofeedback can only be used for patients with an active range of motion (ROM) which is defined as the ability of volitional movement resulting in a change of the concerned limb inclination angle of at least 10 degrees.

| Type of Use (Select one or both, as applicable) | |
|-------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------|
| <label><input checked="" type="checkbox"/> Prescription Use (Part 21 CFR 801 Subpart D)</label> | <label><input type="checkbox"/> Over-The-Counter Use (21 CFR 801 Subpart C)</label> |

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Date of Preparation: 2023-11-20

# Document Control Number: K230701

## 510(k) owner:

PAJUNK® GmbH Medizintechnologie Karl-Hall-Str. 1 78187 Geisingen Baden-Wuerttemberg, Germany Fon: [phone] Fax: [phone] Establishment Registration Number:

## 9611612

## Submitter Information/ production site:

PAJUNK® GmbH Medizintechnologie Karl-Hall-Str. 1 78187 Geisingen Baden-Wuerttemberg, Germany Fon: [phone] Fax: [phone] Establishment Registration Number:

## 9611612

## Contact:

Christian G. H. Quass Director Requlatory Affairs, Safety Officer Patricia Weisbrod Regulatory Affairs Manager Fon: [phone] Fax: [phone] E-Mail: [e-mail] E-Mail: [e-mail]

## USA Contact:

PAJUNK MEDICAL SYSTEMS 4575 Marconi Dr. Alpharetta, GA 30005

## Establishment Registration Number: 3004076349

## Contact

Marco Wohniq President PAJUNK® Medical Systems L.P. Phone: [phone] Direct: [phone] Cell: [phone] Fax: [phone] E-Mail: [e-mail]

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## Device Name and Classification

| Device Name: | Stim2Go |
|------------------------------------|-----------------------------------|
| Regulation Name: | Powered Muscle Stimulator |
| Document Control Number: | K230701 |
| Regulation Number | 21 CFR 890.5850 |
| Product Code: | IPF |
| Subsequent Product Codes | GZI, GZJ, HCC |
| Establishment Registration Number: | 9611612 |
| Regulatory Class: | II |
| Panel: | Physical Medicine |
| Predicate Device | |
| | |
| Device Name: | STIWELL med4 |
| Manufacturer | Otto Bock Healthcare Product GmbH |
| Regulation Name: | Powered Muscle Stimulator |
| Document Clearance Number: | K080950 |
| Regulation Reference: | 21 CFR 890.5850 |
| Product Code: | IPF |
| Subsequent Product Codes | GZI, GZJ, HCC, KPI |
| Establishment Registration Number: | 3005190268 |
| Regulatory Class: | II |

## Narrative Device Description

The Stim2Go is a portable, hand-held / body-worn electrical stimulation device mainly for the treatment of neurological patients with motor and/or sensory impairments. Stim2Go offers transcutaneous electrical stimulation of peripheral nerves (motor and/or sensory).

Typically, Stim2Go is used to elicit muscle contractions (known as Neuro Muscular Electrical Stimulation (NMES)), to treat pain (known as Transcutaneous Electrical Nerve Stimulation (TENS)) or to be applied as Functional Electrical Stimulation (FES).

Stim2Go uses a built-in sensor to analyze the patient's movement data in real time. Based on the analysis result, pre-configured stimulation patterns can be triggered to achieve a specific, predetermined effect based on the patient's movements.

Stim2Go is intended for use in a clinical setting or when used by end users in home care, then necessarily with assistance. It is intended for use as an on-demand service - not permanently.

Stim2Go is controlled wirelessly by a smart device – the App is freely available in the Appstore. The App allows users to execute a variety of therapy programs and even to control parameters on a very detailed level. Stim2Go is tested and certified according to the international standards for medical electrical devices and systems.

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#### Indications for use

As a powered muscle stimulator (NMES) the Stim2Go is indicated for the following conditions:

- Relaxation of muscle spasm ●
- Prevention or retardation of disuse atrophy ●
- . Increasing local blood circulation
- Muscle re-education .
- . Immediate post-surgical stimulation of calf muscles to prevent venous thrombosis
- . Maintaining or increasing range of motion

As a transcutaneous electrical nerve stimulator (TENS) for pain relief the Stim2Go is indicated for the following conditions:

- Symptomatic relief and management of chronic (long-term), intractable pain ●
- . Adjunctive treatment in the management of post-surgical pain and post traumatic acute pain

As a biofeedback device the Stim2Go is indicated for the following condition:

- . Muscle re-education purposes
As a functional neuromuscular stimulator, the Stim2Go is indicated for the following conditions:

- Helps to relearn voluntary motor functions of the extremities .
The movement-based biofeedback can only be used for patients with an active range of motion (ROM) which is defined as the ability of volitional movement resulting in a change of the concerned limb inclination angle of at least 10 degrees.

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## Substantial Equivalence: Side-by-Side-Comparison Tables

## Powered Muscle Stimulator

| Characteristics / Specifications | New Device<br>Stim2Go<br>K230701 | Predicate Device<br>STIWELL med4<br>K080950 | Comment |
|------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------|---------------------------------|
| Basic Unit Characteristics | | | |
| 510(k) Number | K230701 | K080950 | n.a. |
| Device Name, Model | Stim2Go | STIWELL med4 | n.a. |
| Manufacturer | Pajunk GmbH<br>Medizintechnology | Otto Bock | n.a. |
| Power Source(s) | Battery Li-Ion 3.7 V (IEC<br>62133-2 certified) | Battery Pack Li-Ion<br>11 V | Substantially equivalent |
| - Method of Line Current Isolation | Medical class II Power<br>adapter (5VDC - 10W,<br>Globtek) | Medical class II<br>Power adapter<br>(12.6VDC - 15.1W,<br>Mascot) | Substantially equivalent |
| Patient Leakage (Current Normal<br>condition) | n/a (Battery) | n/a (Battery) | Substantially equivalent |
| Patient Leakage Current (Single fault<br>condition) | n/a (Battery) | n/a (Battery) | Substantially equivalent |
| Number of Output Modes | 1 | 1 | Substantially equivalent |
| Characteristics / Specifications | New Device<br>Stim2Go<br>K230701 | Predicate Device<br>STIWELL med4<br>K080950 | Comment |
| Number of Output Channels | 5 | 4 | (PMS1) Substantially equivalent |
| - Synchronous or Alternating? | Alternating | Alternating | Substantially equivalent |
| - Method of Channel Isolation | Each channel is the<br>middle of a H-Bridge.<br>Except when it is<br>activated, each channel is<br>always in high impedance<br>state. | Transformer,<br>Inductive couplers | (PMS2) Substantially equivalent |
| Regulated Current or Regulated<br>Voltage? | Regulated current | Regulated current | Substantially equivalent |
| Software/Firmware/Microprocessor<br>Control? | Yes | Yes | Substantially equivalent |
| Automatic Overload Trip? | Yes | Yes | Substantially equivalent |
| Automatic No-Load Trip? | Yes | Yes | Substantially equivalent |
| Automatic Shut Off? | Yes (15 min) | Yes (10 min) | Substantially equivalent |
| Patient Override Control? | Yes (STOP Button) | Yes (STOP Button) | Substantially equivalent |
| Indicator Display: | | | |
| Characteristics / Specifications | New Device<br>Stim2Go<br>K230701 | Predicate Device<br>STIWELL med4<br>K080950 | Comment |
| - On/Off Status? | Yes | Yes | Substantially equivalent |
| - Low Battery? | Yes | Yes | Substantially equivalent |
| - Voltage/Current Level? | Yes | Yes | Substantially equivalent |
| Timer Range (minutes) | 1-120 min | 2-120 min | Substantially equivalent |
| Compliance with Voluntary Standards? | IEC 60601, IEC 60601-1-<br>2, IEC 60601-1-6, IEC<br>60601-1-11, IEC 60601-2-<br>10, IEC 62304 | IEC 60601-1, IEC<br>60601-1-2, IEC<br>60601-2-10 | Substantially equivalent |
| Compliance with 21 CFR 898? | Yes | Yes | Substantially equivalent |
| Weight | 185 g | 440 g | Substantially equivalent |
| Dimensions (in.) [W x H x D] | 120 x 80 x 25 mm | 175 x 95 x 30 mm | Substantially equivalent |
| Housing Materials and Construction | Plastics | Plastics | Substantially equivalent |
| Output Specifications | | | |
| Waveform (e.g., pulsed monophasic,<br>biphasic) | Biphasic symmetrical | Biphasic symmetrical | Substantially equivalent |
| Characteristics / Specifications | New Device<br>Stim2Go<br>K230701 | Predicate Device<br>STIWELL med4<br>K080950 | Comment |
| Shape (e.g., rectangular, spike, rectified<br>sinusoidal) | Rectangular | Rectangular | Substantially equivalent |
| Maximum Output Voltage (500 Ω) | 50V @ 500 Ω | 50V @ 500 Ω | Substantially equivalent |
| Maximum Output Voltage (2 kΩ) | 115V @ 2 kΩ | 115V @ 2 kΩ | Substantially equivalent |
| Maximum Output Voltage (10 kΩ) | 115V @ 10 kΩ | 125V @ 10 kΩ<br>(Measured) | (PMS3) Substantially equivalent |
| Maximum Output Current (500 Ω) | 100 mA @ 500 Ω | 100 mA @ 500 Ω | Substantially equivalent |
| Maximum Output Current (2 kΩ) | 50 mA @ 2 kΩ | 58 mA @ 2 kΩ | Substantially equivalent |
| Maximum Output Current (10 kΩ) | 11 mA @ 10 kΩ | 14 mA @ 10 kΩ<br>(Measured) | (PMS3) Substantially equivalent |
| Pulse Width (specify units) | 30-400μs (default)<br>(30-750 μs in steps of 10<br>μs, adjustable only by<br>therapists) | 50-400 μs | (PMS4) Substantially equivalent |
| Frequency (Hz) | 1,2,3,4,5,10,16,20,25,33,<br>50,100 Hz | 1 - 140 Hz | (PMS4) Substantially equivalent |
| For interferential modes only:<br>- Beat Frequency (Hz) | n/a | n/a | Substantially equivalent |
| Characteristics / Specifications | New Device<br>Stim2Go<br>K230701 | Predicate Device<br>STIWELL med4<br>K080950 | Comment |
| For multiphasic waveforms only:<br>- Symmetrical phases? | n/a | n/a | Substantially equivalent |
| For multiphasic waveforms only:<br>- Phase Duration (include units) (state<br>range, if applicable) (both phases, if<br>asymmetrical) | n/a | n/a | Substantially equivalent |
| Net Charge (m C per pulse): @500 Ω | 0 µC (Same positive and<br>negative impulse) | 0 µC (Same positive<br>and negative impulse) | Substantially equivalent |
| Maximum Phase Charge, (µC) @500 Ω | 75 µC (for 750 µs) | 40µC (for 400 µs) | (PMS5) Substantially equivalent |
| Maximum Current Density, (mA/cm²) @<br>500 Ω | 12.5 mA / cm² | 12.5 mA / cm² | Substantially equivalent |
| Maximum Power Density, (W/cm²) @<br>500 Ω (using smallest electrode<br>conductive surface area) | 14.0 mW / cm² | 7.9 mW / cm² | Substantially equivalent |
| Burst Mode (i.e., pulse trains) a. Pulses<br>per burst<br>b. Bursts per second<br>c. Burst duration (seconds)<br>d. Duty Cycle [Line (b) x Line (c)] | n/a n/a n/a n/a | n/a n/a n/a n/a | Substantially equivalent |
| ON Time (seconds) | 0.1 - 59 sec | 1 - 20 sec | Substantially equivalent |
| Characteristics / Specifications | New Device<br>Stim2Go<br>K230701 | Predicate Device<br>STIWELL med4<br>K080950 | Comment |
| OFF Time (seconds) | 0.1 - 59 sec | 1 - 50 sec | Substantially equivalent |
| Additional Features (if applicable) | n/a | n/a | Substantially equivalent |

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(PMS1) Although the "Number of Output Channels" is different from the predicate device they both comply with IEC 60601-2-10 requirements and the difference doesn't impact essential performance, basic safety or substantial equivalence.

(PMS2) The channel isolation for both devices have been measured isolation resistor values for the predicate and new device can only result in a maximum current from one channel of 9 nA and 14 nA, respectively. In the standard IEC 60601-1 section 8.7.3 the allowable values of the touch current are 100 µA in normal condition is goth devices the new and the predicate device are factor 10000 lower than the maximum allowable value. Therefore, both tested devices comply with IEC 60601-1 and IEC 60601-2-10 requirements and the difference doesn't impact essential performance, basic safety, or substantial equivalence.

(PMS3) Both devices stop stimulating at low currents reporting an electrode error for a 10 kOhm load resister. The measured currents are very low.

(PMS4) The pulse width and frequency used in the standard powered muscle stimulation programs are substantially equivalent to the corresponding programs and default settings of the new device has a lower maximum frequency (100 Hz) and a higher maximum pulse width (750μs) compared to the predicate device. Both parameters can only be adjusted by therapists (e.g., for patients with high BMI). Both tested devices comply with the requirements of IEC 60601-2-10. The differences in pulse with and frequency do not impact essential performance, effectiveness, safety, or substantial equivalence.

(PMS5) A maximum pulse width of 750us and a maximum current amplitude of 100 mA results in a maximum phase charge of 75gC, which is considered safe (classification 21CFR890.5850). In addition, both tested devices comply with the requirements of EC 60601-1 and IEC 60601-2-10. The difference in maximum phase charge doesn't impact effectiveness, salety, or substantial equivalence.

None of these differences, raise any new issues of the new device compared to the predicate device. All respective standards have been applied during compliance testing.

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## Functional Electrical Stimulation Programs (non-triggered):

| Characteristics | | | New Device | Predicate Device | |
|--------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------|---------------------------------------|
| / Specifications | New Device | Predicate<br>Device | Stim2Go | STIWELL med4 | Comment |
| | | | K230701 | K080950 | |
| Basis Units Characteristics | | | | | |
| Program | Grasp and Release | FES 1<br>Grasp/Release | Open and Close | FES 3 Open / Close | n/a |
| 510(k) Numbers | K230701 | K080950 | K230701 | K080950 | n/a |
| Manufacturer | Pajunk GmbH<br>Medizintechnology | Otto Bock | Pajunk GmbH<br>Medizintechnology | Otto Bock | n/a |
| Device Name,<br>Model | Stim2Go | STIWELL med4 | Stim2Go | STIWELL med4 | n/a |
| Power Source(s) | Battery Li-Ion 3.7 V (IEC<br>62133-2 certified) | Battery Pack Li-<br>lon 11 V | Battery Li-Ion 3.7<br>V (IEC 62133-2<br>certified) | Battery Pack Li-Ion 11 V | Substantially<br>equivalent |
| Method of Line<br>Current Isolation | Medical class II Power<br>adapter (5VDC - 10W,<br>Globtek) | Medical class II<br>Power adapter<br>(12.6VDC -<br>15.1W, Mascot) | Medical class II<br>Power adapter<br>(5VDC - 10W,<br>Globtek) | Medical class II Power<br>adapter (12.6VDC -<br>15.1W, Mascot) | Substantially<br>equivalent |
| Leakage Current<br>(normal<br>condition) | n/a (Battery) | n/a (Battery) | n/a (Battery) | n/a (Battery) | Substantially<br>equivalent |
| Leakage Current<br>(single fault<br>condition) | n/a (Battery) | n/a (Battery) | n/a (Battery) | n/a (Battery) | Substantially<br>equivalent |
| No. Output Mod. | 1 | 1 | 1 | 1 | Substantially<br>equivalent |
| No. Output Chan. | 3 | 3 | 3 | 3 | Substantially<br>equivalent |
| Stimulated<br>Muscle(s) | Wrist extensors<br>Finger flexors<br>Thumb flexor | Wrist extensors<br>Finger flexors<br>Thumb flexor | Finger/thumb<br>extensors<br>Finger flexors<br>Thumb flexor | Finger/thumb extensors<br>Finger flexors<br>Thumb flexor | Substantially<br>equivalent |
| Characteristics<br>/ Specifications | New Device | Predicate<br>Device | New Device | Predicate Device | Comment |
| | | | Stim2Go<br>K230701 | STIWELL med4<br>K080950 | |
| No. of Sensor<br>Channels | 0 | 0 | 0 | 0 | Substantially<br>equivalent |
| Sensor<br>Sensitivity | n/a | n/a | n/a | n/a | Substantially<br>equivalent |
| Sensor Sample<br>Rate | n/a | n/a | n/a | n/a | Substantially<br>equivalent |
| Sensor Detection | n/a | n/a | n/a | n/a | Substantially<br>equivalent |
| Sensor Range | n/a | n/a | n/a | n/a | Substantially<br>equivalent |
| Sensor<br>Bandwidth | n/a | n/a | n/a | n/a | Substantially<br>equivalent |
| Sensor Signal<br>Proc. | n/a | n/a | n/a | n/a | n/a |
| Synchr. Or<br>Altern.? | Alternating | Alternating | Alternating | Alternating | Substantially<br>equivalent |
| Meth. Chan. Isol. | Each channel is the middle<br>of a H-Bridge. Except when<br>it is activated, each channel<br>is always in high impedance<br>state. | Transformer,<br>Inductive<br>couplers | Each channel is<br>the middle of a H-<br>Bridge. Except<br>when it is<br>activated, each<br>channel is always<br>in high impedance<br>state. | Transformer, Inductive<br>couplers | (FES1)<br>Substantially<br>equivalent |
| Regulated<br>Current or<br>Regulated<br>Voltage? | Regulated current | Regulated<br>current | Regulated current | Regulated current | Substantially<br>equivalent |
| Characteristics<br>/ Specifications | New Device | Predicate Device | New Device<br>Stim2Go<br>K230701 | Predicate Device<br>STIWELL med4<br>K080950 | Comment |
| Software<br>/Firmware/<br>Microprocessor<br>Control? | Yes | Yes | Yes | Yes | Substantially<br>equivalent |
| Automatic<br>Overload Trip? | Yes | Yes | Yes | Yes | Substantially<br>equivalent |
| Automatic No-<br>Load Trip? | Yes | Yes | Yes | Yes | Substantially<br>equivalent |
| Automatic Shut<br>Off? | Yes (15 min) | Yes (10 min) | Yes (15 min) | Yes (10 min) | Substantially<br>equivalent |
| Patient Override<br>Control? | Yes (STOP Button) | Yes (STOP Button) | Yes (STOP Button) | Yes (STOP Button) | Substantially<br>equivalent |
| Indicator<br>Display: | | | | | |
| - On/Off Status? | Yes | Yes | Yes | Yes | Substantially<br>equivalent |
| - Low Battery? | Yes | Yes | Yes | Yes | Substantially<br>equivalent |
| - Voltage/Current<br>Level? | Yes | Yes | Yes | Yes | Substantially<br>equivalent |
| Timer Range<br>(minutes) | 1-60; default 30 min | 15-60 | 1-60; default 30<br>min | 15-60 | Substantially<br>equivalent |
| Compliance with<br>Voluntary<br>Standards? | IEC 60601, IEC 60601-1-2,<br>IEC 60601-1-6, IEC 60601-<br>1-11, IEC 60601-2-10, IEC<br>62304 | IEC 60601-1,<br>IEC 60601-1-2,<br>IEC 60601-2-10 | IEC 60601, IEC<br>60601-1-2, IEC<br>60601-1-6, IEC<br>60601-1-11, IEC<br>60601-2-10, IEC<br>62304 | IEC 60601-1, IEC<br>60601-1-2, IEC 60601-<br>2-10 | Substantially<br>equivalent |
| Characteristics<br>/ Specifications | New Device | Predicate Device | New Device | Predicate Device | Comment |
| | | | Stim2Go<br>K230701 | STIWELL med4<br>K080950 | |
| Compliance with<br>21 CFR 898? | Yes | Yes | Yes | Yes | Substantially<br>equivalent |
| Weight | 185 g | 440 g | 185 g | 440 g | Substantially<br>equivalent |
| Dimensions (in.)<br>[W x H x D] | 120 x 80 x 25 mm | 175 x 95 x 30 mm | 120 x 80 x 25 mm | 175 x 95 x 30 mm | Substantially<br>equivalent |
| Housing<br>Materials and<br>Construction | Plastics | Plastics | Plastics | Plastics | Substantially<br>equivalent |
| Output Specification | | | | | |
| Waveform | Biphasic symmetrical | Biphasic<br>symmetrical | Biphasic symmetrical | Biphasic symmetrical | Substantially<br>equivalent |
| Rectangular | Rectangular | Rectangular | Rectangular | Rectangular | Substantially<br>equivalent |
| Maximum<br>Output Voltage<br>(500 Ω) | 50V @ 500 Ω | 50V @ 500 Ω | 50V @ 500 Ω | 50V @ 500 Ω | Substantially<br>equivalent |
| Maximum<br>Output Voltage<br>(2 kΩ) | 115V @ 2 kΩ | 115V @ 2 kΩ | 115V @ 2 kΩ | 115V @ 2 kΩ | Substantially<br>equivalent |
| Maximum<br>Output Voltage<br>(10 kΩ) | 115V @ 10 kΩ | 125V @ 10 kΩ<br>(Measured) | 115V @ 10 kΩ | 125V @ 10 kΩ<br>(Measured) | (FES2)<br>Substantially<br>equivalent |
| Maximum Output<br>Current<br>(500 Ω) | 100 mA @ 500 Ω | 100 mA @ 500 Ω | 100 mA @ 500 Ω | 100 mA @ 500 Ω | Substantially<br>equivalent |
| Maximum Output<br>Current<br>(2 kΩ) | 50 mA @ 2 kΩ | 58 mA @ 2 kΩ | 50 mA @ 2 kΩ | 58 mA @ 2 kΩ | Substantially<br>equivalent |
| Characteristics / Specifications | New Device | Predicate Device | New Device | Predicate Device | Comment |
| | | | Stim2Go<br>K230701 | STIWELL med4<br>K080950 | |
| Maximum Output Current (10 kΩ) | 11 mA @ 10 kΩ | 14 mA @ 10 kΩ (Measured) | 11 mA @ 10 kΩ | 14 mA @ 10 kΩ (Measured) | (FES2) Substantially equivalent |
| Pulse Width (specify units) | 30-400µs (default)<br>(30-750 µs in steps of 10 µs, adjustable only by therapists) | 50-400µs | 30-400µs (default)<br>(30-750 µs in steps of 10 µs, adjustable only by therapists) | 50-400µs | (FES3) Substantially equivalent |
| Frequency (Hz) | 1-100Hz (default 33 Hz) | 1-140 Hz; default 35 Hz | 1-100Hz (default 33 Hz) | 1-140 Hz; default 35 Hz | (FES3) Substantially equivalent |
| Net Charge [µC] (500 Ω) | 0 µC (Same positive and negative impulse) | 0 µC (Same positive and negative impulse) | 0 µC (Same positive and negative impulse) | 0 µC (Same positive and negative impulse) | Substantially equivalent |
| Maximum Phase Charge [µC] (500 Ω) | 75 µC (for 750 µs) | 40 µC (for 400 µs) | 75 µC (for 750 µs) | 40 µC (for 400 µs) | (FES4) Substantially equivalent |
| Maximum Current Density [mA/cm²] (500 Ω) | 12.5 mA/cm² | 12.5 mA/cm² | 12.5 mA/cm² | 12.5 mA/cm² | Substantially equivalent |
| Maximum Power Density [W/cm²] (500 Ω) | 14 mW / cm^2 | 7.9 mW/cm² | 14 mW / cm^2 | 7.9 mW/cm² | Substantially equivalent |
| Burst Mode (i.e., pulse trains): Pulses per burst | n/a | n/a | n/a | n/a | n/a |
| Burst Mode (i.e., pulse trains): Bursts per second | n/a | n/a | n/a | n/a | n/a |
| Characteristics<br>/ Specifications | New Device | Predicate Device | New Device<br>Stim2Go<br>K230701 | Predicate Device<br>STIWELL med4<br>K080950 | Comment |
| Burst Mode (i.e.,<br>pulse trains):<br>Burst duration<br>(seconds) | n/a | n/a | n/a | n/a | n/a |
| Duty Cycle [Line<br>(b) x Line (c)] | n/a | n/a | n/a | n/a | n/a |
| ON Time<br>[seconds] | 1-60 s; default 20 | 1-20 s | 1-60 s; default 20 | 1 – 20 s | Substantially<br>equivalent |
| OFF Time<br>[seconds] | 1-60 s; default 30 | 1-30 s | 1-60 s; default 20 | 1 – 30 s | Substantially<br>equivalent |
| Additional<br>features | n/a | n/a | n/a | n/a | n/a |
| Characteristics<br>/ Specifications | New Device | Predicate<br>Device | New Device<br>Stim2Go<br>K230701 | Predicate Device<br>STIWELL med4<br>K080950 | Comment |
| Basis Units Characteristics | | | | | |
| Program | Triggered Grasp and<br>Release<br>K230701 | FES 2<br>Grasp/Release<br>K080950 | Triggered Open<br>and Close<br>K230701 | FES 4<br>Open / Close<br>K080950 | n/a |
| 510(k) Numbers | | | | | n/a |
| Manufacturer | Pajunk GmbH<br>Medizintechnology | Otto Bock | Pajunk GmbH<br>Medizintechnology | Otto Bock | n/a |
| Device Name,<br>Model | Stim2Go | STIWELL med4 | Stim2Go | STIWELL med4 | n/a |
| Power Source(s) | Battery Li-Ion 3.7 V (IEC<br>62133-2 certified) | Battery Pack Li-<br>lon 11 V | Battery Li-Ion 3.7<br>V (IEC 62133-2<br>certified) | Battery Pack Li-Ion 11 V | Substantially<br>equivalent |
| Method of Line<br>Current Isolation | Medical class II Power<br>adapter (5VDC - 10W,<br>Globtek) | Medical class II<br>Power adapter<br>(12.6VDC -<br>15.1W, Ma…