Relaxation of muscle spasms
Prevention or retardation of disuse atrophy
Increasing local blood circulation
Maintaining or increasing range of motion
The RehaStim 2 is an External Functional Neuromuscular Stimulator, designed for use as stand-alone device as well as in combination with exercise equipment for walking and cycling applications, that has been validated for compatibility by HASOMED GmbH and should be used under the supervision of a clinician.

Device Description

RehaStim 2 is a 8 channel External Functional Neuromuscular Stimulator. RehaStim 2 can be used as a stand-alone device or in combination with an external motion trainer for cycling or walking applications, that has been validated for compatibility by HASOMED GmbH and should be used under the supervision of a clinician.
A connection cable enables the RehaStim 2 to receive motion data from the external movement exerciser device for walking or cycling applications in order to apply electrical stimulation synchronized with the movement. The stimulation is performed according to the motion data. The stimulation parameters can be configured inside the stimulator.
Electrode lead wires are used to connect RehaStim2 output and electrodes on skin.

AI/ML Overview

The provided text describes the RehaStim 2 device, an External Functional Neuromuscular Stimulator. The text includes information about its indications for use, comparison to predicate devices, and performance data from non-clinical testing for 510(k) clearance.

Here's an analysis of the provided information concerning acceptance criteria and studies:

1. Table of acceptance criteria and the reported device performance:

The document does not explicitly state acceptance criteria in a quantitative, measurable format with corresponding device performance metrics. Instead, it relies on demonstrating equivalence to predicate devices and verifying that the device performs according to specifications.

The closest to "acceptance criteria" are the technical specifications listed in the comparison table, which the RehaStim 2 (2016) device meets by being largely identical or having differences that "do not raise new questions of safety and effectiveness."

Acceptance Criteria (Implied / Demonstrated by Equivalence)	Reported Device Performance (RehaStim 2 (2016))
Output Characteristics:
Charge-balanced stimulation (0-130mA)	0-130mA charge balanced stimulator with rectangular impulses / same hardware as predicates
Pulse width: max. 500 µs	max. 500 µs
Stimulation frequency: max. 50 Hz	max. 50 Hz
Number of channels: 8	8
Power Source:
AC and/or storage battery (cincon tr30m, BMZ18650 V, Li-Ion)	AC and/or storage battery: cincon tr30m, BMZ18650 V, Li-Ion Mangan cells, 2S1P, C= 1600 mAh
Power input (charging): 9V, 3A, max. 30 W	9V, 3A, max. 30 W
Operation time: ca. 90 min	ca. 90 min
Charging time: ca. 180 min	ca. 180 min
Controller:
Uses custom controller with embedded Linux, running custom SW	Uses custom controller using embedded Linux as basis operating system, running custom software
Electrodes:
Compatibility with HASOMED's RehaTrodes	HASOMED's RehaTrodes only (FES00200 2.0"x3.5", FES00201 3.0"x5.0", FES00202 1.5"x2.5" oval)
Applied Part:
Type BF	Type BF
Movement Exerciser Compatibility:
Intended for combination with different movement exercisers	Intended for combination with different movement exercisers for walking and cycling applications (validated for compatibility by HASOMED GmbH, used under clinician supervision)
Communication interface: FES 2 + FES 3	FES 2 + FES 3; FES 3 - bidirectional communication, controlling of movement exerciser functionality, interface allows for combination with different devices
Control philosophy: Complete stimulation control in RehaStim 2	Complete stimulation control implemented in RehaStim 2, movement exerciser delivers motion data for synchronization of stimulation and movement (differs from ErigoPro where some control is in Erigo device)
Database interface:
Utilizes database interface	Utilizes database interface for storage and retrieval of patient therapy settings and storage of session logs
Safety and Effectiveness:	"The safety and effectiveness of the single stimulator device RehaStim 2 is extensively demonstrated by using the device for many years." "The safety and effectiveness...have been extensively demonstrated by the ongoing use of the predicate devices."
Compliance:	"Hardware and software verification and validation demonstrate that the device will perform as intended in the specified use conditions."

2. Sample size used for the test set and the data provenance:

Sample Size for Test Set: The document explicitly states "no clinical testing was required." The performance data section refers to "Output characteristic measurement of new device" and "Control of system testing." These are non-clinical tests. Therefore, there is no "test set" in the sense of a patient cohort. The "sample" for these tests would be the devices themselves. The number of devices tested is not specified but would typically imply a representative number from manufacturing.
Data Provenance: The testing is "non-clinical data," implying laboratory or bench testing performed by HASOMED GmbH ("proprietary testing protocol conducted by Hasomed GmbH"). The country of origin for the company is Germany.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

This information is not applicable as no clinical ground truth was established for a patient test set, because "no clinical testing was required." The basis for the device's substantial equivalence is its technical characteristics and its similarity to predicate devices, supported by non-clinical verification and validation.

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

Not applicable, as no clinical test set requiring expert adjudication for ground truth was used.

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:

Not applicable. This device is an External Functional Neuromuscular Stimulator, not an AI-powered diagnostic imaging device that would typically undergo an MRMC study with human readers. The document states "no clinical testing was required."

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

The device itself is a "stand-alone device" meaning it can function on its own or in combination with exercise equipment. The performance data section describes "Output characteristic measurement of new device" and "Control of system testing" which are standalone performance assessments, but this is for the hardware and software of the device itself, not an algorithm separated from a human operator in a diagnostic context. The device is intended to be used "under the supervision of a clinician," indicating a human-in-the-loop for its clinical application.

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

No clinical "ground truth" was used for human-patient data because no clinical testing was required. The "ground truth" for the device's technical performance was its design specifications and the technical characteristics of the predicate devices. The safety and effectiveness were supported by:

Extensive historical use of the single stimulator device RehaStim 2.
Ongoing use of predicate devices (RehaStim 2 / ErigoPro (FES) and RehaStim 2 / RehaMove 2) in combination with movement exercisers.
Hardware and software verification and validation against specifications.

8. The sample size for the training set:

Not applicable. The document does not describe the use of machine learning or AI models that would require a "training set." The device is a traditional medical device (neuromuscular stimulator), not an AI/ML algorithm-based device.

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

Not applicable, as there is no mention of a training set or machine learning.

Summary

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Image /page/0/Picture/1 description: The image shows the logo for the Department of Health & Human Services - USA. The logo consists of a circular arrangement of the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA". Inside the circle is a symbol of three stylized human profiles facing to the right. The profiles are stacked on top of each other, creating a sense of depth and unity.

Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002

February 3, 2017

HASOMED Gmbh Matthias Ueltzen Quality Management & Regulatory Affairs Paul-Ecke-Str. 1 Magdeburg, SA 39114 Germany

Re: K162683

Trade/Device Name: RehaStim 2 Regulation Number: 21 CFR 882.5810 Regulation Name: External Functional Neuromuscular Stimulator Regulatory Class: Class II Product Code: GZI Dated: December 22, 2016 Received: December 27, 2016

Dear Mr. Ueltzen:

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, 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 801); medical device reporting (reporting of medical device

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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/ResourcesforYou/Industry/default.htm. 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.

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,

Michael J. Hoffmann -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) K162683

Device Name RehaStim 2

Indications for Use (Describe) The RehaStim 2 stimulator is intended for general rehabilitation

1. Relaxation of muscle spasms
1. Prevention or retardation of disuse atrophy
1. Increasing local blood circulation
1. Maintaining or increasing range of motion

The RehaStim 2 is an External Functional Neuromuscular Stimulator, designed for use as stand-alone device as well as in combination with exercise equipment for walking and cycling applications, that has been validated for compatibility by HASOMED GmbH and should be used under the supervision of a clinician.

Type of Use (Select one or both, as applicable)
-------------------------------------------------	--

X Prescription Use (Part 21 CFR 801 Subpart D)

Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) Summary

l. SUBMITTER

510k Submitter:	Hasomed GmbH
Contact person:	Matthias Weber
Address:	Paul-Ecke-Strasse 139114 MagdeburgGermany
Phone:	+493916230112
Fax:	+493916230113

Prepared 2016-09-22, revised 2016-11-22, 2017-01-20, 2017-01-26, and 2017-02-02.

II. DEVICE

Modification to an existing device

Proprietary name:	RehaStim 2
Common Name:	Powered Muscle Stimulator
Classification Name:	Powered Muscle Stimulator
Device Class:	class 2 device
Classification:	Neurology
Product code:	GZI

III. PREDICATE DEVICE

Device 1 – primary predicate

RehaStim 2; Proprietary name:

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	RehaMove 2 (RehaStim 2 with movement exerciser)
510(k):	K112844
Device Class:	class 2 device
Classification:	Neurology
Product code:	GZI
Common Name:	Powered Muscle Stimulator

Device 2

Proprietary name:	RehaStim 2;
	ErigoPro (FES)
510(k):	K132416
Device Class:	class 2 device
Classification:	Neurology
Product code:	GZI, BXB, INQ
Common Name:	Powered Muscle Stimulator

IV. DEVICE DESCRIPTION

A connection cable enables the RehaStim 2 to receive motion data from the external movement exerciser device for walking or cycling applications in order to apply electrical stimulation synchronized with the movement. The stimulation is performed according to the motion data. The stimulation parameters can be configured inside the stimulator.

Electrode lead wires are used to connect RehaStim2 output and electrodes on skin.

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V. INDICATIONS FOR USE

The RehaStim 2 stimulator is intended for general rehabilitation for:

1. Relaxation of muscle spasms
1. Prevention or retardation of disuse atrophy
1. Increasing local blood circulation
1. Maintaining or increasing range of motion

VI. COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE

The functions of the RehaStim 2 (2016) are the same as the predicate devices ErigoPro (FES), RehaMove 2, and RehaStim 2 remained the same, however there are certain technological similarities and differences as described below:

Technology	RehaStim 2(2016)	RehaStim 2 /ErigoPro (FES)	RehaStim 2 /RehaMove 2
		K132416	K112844primary predicate
Power Source	AC and/or storagebattery:Power supply:cincon tr30m ac-cording toEN60601-1Battery:BMZ18650 V, Li-Ion Mangan cells,2S1P, C= 1600mAh,	AC:ErigoPro:Total System: 110-230V 800VAIncludesRehaStim2 powersupply: cincontr30m according toEN60601-1	AC and/or storagebattery:Power supply:cincon tr30m ac-cording toEN60601-1Battery:BMZ18650 V, Li-Ion Mangan cells,2S1P, C= 1600mAh,
		RehaStim2 (only):AC: power supply:cincon tr30m ac-cording toEN60601-1Battery:BMZ18650 V, Li-Ion Mangan cells,2S1P, C= 1600mAh,
Power input(charging)	9V, 3A, max. 30 W	RehaStim2: 9V,3A, max. 30 W	9V, 3A, max. 30 W
Operation time	ca. 90 min	ErigoPro: Nolimitation bybatteryRehaStim2: ca. 90min	ca. 90 min
Charging time	ca. 180 min	ErigoPro: N/ARehaStim2: ca.180 min	ca. 180 min
Controller	uses customcontrollerusing embeddedLinux as basisoperating system,running customsoftware	uses customcontrollerusing embeddedLinux as basisoperating system,running customsoftwareErigoPro:RehaStim2 iscontrolled by	uses customcontrollerusing embeddedLinux as basisoperating system,running customsoftware
		ErigoPro ControlPanel
Stimulator(energy delivered)	0-130mA chargebalancedstimulator withrectangularimpulses / samehardware	0-130mA chargebalancedstimulator withrectangularimpulses / samehardware	0-130mA chargebalancedstimulator withrectangularimpulses / samehardware
Pulse width	max. 500 µs	max. 500 µs	max. 500 µs
Stimulationfrequency	max. 50 Hz	max. 50 Hz	max. 50 Hz
Number ofchannels	8	8	8
Electrodes	HASOMED'sRehaTrodes only	HASOMED'sRehaTrodes onlyErigoPro:HASOMED'selectrodes with"distributed byHocoma" label	HASOMED'sRehaTrodes only
FES00200RehaTrode	2.0" x 3.5",rectangle	2.0" x 3.5",rectangle	2.0" x 3.5",rectangle
FES00201RehaTrode	3.0" x 5.0",rectangle	3.0" x 5.0",rectangle	3.0" x 5.0",rectangle
FES00202RehaTrode	1.5" x 2.5" oval	1.5" x 2.5" oval	1.5" x 2.5" oval
Applied part	Type BF	Type BF	Type BF
Movement	RehaStim 2 (2016)	ErigoPro: uses	RehaMove: Uses
exerciser	is intended forcombination withdifferent movementexercisers forwalking andcyclingapplications	motor to robotic legmovement andcyclic leg loadingfor early functionalmobilization	motor to createflywheel effect withreduced weightand space
Communicationinterface	FES 2 + FES 3;FES 3-bidirectionalcommunication,controlling ofmovementexerciserfunctionalityinterface allows forcombination withdifferent devices	RehaStim2:FES 2 + FES 3;FES 3-bidirectionalcommunication,controlling ofmovementexerciserfunctionalityErigoPro: RS2-ErigoMode -bidirectionalcommunication,controlling of FES,synchronized withthe ErigoProdevice	FES 2 + FES 3;FES 3-bidirectionalcommunication,controlling ofmovementexerciserfunctionality
Control philosophyof matching thecombined devices	Completestimulation controlimplemented inRehaStim 2,movementexerciser deliversmotion data forsynchronization ofstimulation andmovement	Parts of stimulationcontrolimplemented inErigo device	Completestimulation controlimplemented inRehaStim 2,movementexerciser deliversmotion data forsynchronization ofstimulation andmovement
Patient position	As usual in themovementexerciser devicecombined with	Verticalizationtable for earlyrehabilitation	Allows user toremain in their ownseating, e.g.wheelchaireliminating theneed for transfer
Passive cycling	Exerciseequipment: Utilizesmotor to provideassistance duringpassive walking orcycling	ErigoPro (FES):Utilizes motor forrobotic legmovement andcyclic leg loading	RehaMove:Utilizes motor toprovide assistanceduring passivecycling
Database interface	Utilizes databaseinterface forstorage andretrieval of patienttherapy settingsand storage ofsession logs	Utilizes databaseinterface forstorage andretrieval of patienttherapy settingsand storage ofsession logs	Utilizes databaseinterface forstorage andretrieval of patienttherapy settingsand storage ofsession logs

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Table 1 Technological similarities and differences

The difference is in the control philosophy of the device combinations: In RehaStim 2 / RehaMove 2 the complete stimulation know-how is in the controller of the stimulation device RehaStim 2. In ErigoPro (FES) some of the stimulation control is implemented in the Erigo control. In the new device, stimulation control is completely implemented in the stimulation device and an interface is used for input of motion data into the stimulator. The stimulation is performed according to the motion data. The motion data are delivered via a serial interface (USB, FTDI) as percentage of full gait cycle at a rate of about 10 ms from the exerciser to the stimulator. A proprietary protocol is used. Based on this gait information, stimulation is activated at pre-defined values to the muscles needed according to the actual phase of gait. A proprietary testing protocol conducted by Hasomed GmbH is being used for validation and verification of RehaStim 2 for use with an exercise equipment. Hasomed will conduct risk hazard analysis to determine if additional testing (e.g. electrical safety, EMC, verification and validation) is necessary to ensure safety and effectiveness when using the RehaStim 2 with an exercise equipment.

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VII. PERFORMANCE DATA

The RehaStim 2 (2016) and both predicate devices (ErigoPro (FES) and RehaStim 2 / RehaMove 2) have the same intended use and the same output characteristics. The different technological characteristics do not raise new questions of safety and effectiveness.

The safety and effectiveness of the single stimulator device RehaStim 2 is extensively demonstrated by using the device for many years.

The safety and effectiveness of combining the electrostimulation device RehaStim 2 with movement exercisers or with devices for early functional mobilization of bedridden patients have been extensively demonstrated by the ongoing use of the predicate devices RehaStim 2 / ErigoPro (FES) and RehaStim 2 / RehaMove 2, respectively.

The safety and effectiveness of the controller has been demonstrated over the development period of the RehaStim 2 (2016). For combining the device with exercise equipment for walking and cycling applications, clear assessment instructions for verification and validation ensure, that no new questions of safety and effectiveness can be introduced by the combination of the products.

Test or procedure	Task
Review of user documentation forpredicate device	It was reviewed that equivalentfunctionality was implemented.
Review of 510(k) submissions forpredicate device	Confirm technical specifications forcompletion of predicate details incomparison tables (see above)
Output characteristic measurement ofnew device	The RehaStim 2 (2016) device wastested and technically compared withthe predicate devices.
Control of system testing	The system testing was aligned toverify performance to specification.

Determination of substantial equivalence

Table 2 Performance data

It can be matched that there is a substantial equivalence in all important technical and medical characteristics to the predicate devices.

VIII. CONCLUSIONS

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510(k) RehaStim 2 (2016)

Since the intended use of the predicate devices is the same and the therapeutic parameters did not change, no clinical testing was required. The non-clinical data support the safety of the device and the hardware and software verification and validation demonstrate that the device will perform as intended in the specified use conditions. Hasomed concludes that the device performs comparably to the predicate devices that are currently marketed for the same intended use.

Regulation Number and Section

§ 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).