(130 days)
The RehaStim 2 stimulator is intended for general rehabilitation for:
- 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.
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.
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.
§ 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).