(171 days)
The RT300-S (adult version) and RT300-SP (pediatric version) are intended for general rehabilitation for:
- a. Relaxation of muscle spasms
- b. Prevention or retardation of disuse atrophy
- c. Increasing local blood circulation
- d. Maintaining or increasing range of motion
The RT300-SP (pediatric version), is intended for population ages 4 to 12 years.
The RT300-S is a Functional Electrical Stimulation (FES) cycle ergometer which is composed of:
- a motorized cycle ergometer (RTI part number SA100047 for adults and SA100044 for children)
- an FES controller / stimulator (RTI part number SA100090)
- a stimulation cable which connects the controller / stimulator to cutaneous electrodes (RTI part number SA100091)
- cutaneous electrodes (12 electrodes for 6 stimulation channels, RTI part number FA100015)
This system allows a person with impaired lower extremity movement to undertake cycle ergometry both actively (utilizing FES evoked lower extremity muscle contractions) and passively (utilizing power developed by the ergometer's motor).
RT300-S Acceptance Criteria and Supporting Study
The RT300-S and RT300-SP devices are Functional Electrical Stimulation (FES) cycle ergometers intended for general rehabilitation. The substantial equivalence determination for K050036 is based on its comparison to the predicate device, THERAPEUTIC ALLIANCES, INC. product: "ERGYS" (K841112).
1. Acceptance Criteria and Reported Device Performance
The acceptance criteria for the RT300-S and RT300-SP are implicitly defined by demonstrating substantial equivalence to the predicate device, "ERGYS" (K841112), based on intended use, technological characteristics, and safety and effectiveness.
| Acceptance Criteria (Demonstration of Substantial Equivalence) | Reported Device Performance (RT300-S/SP) |
|---|---|
| Same intended use as predicate device | RT300-S/SP has the same intended use for general rehabilitation: relaxation of muscle spasms, prevention/retardation of disuse atrophy, increasing local blood circulation, maintaining/increasing range of motion. |
| Same output characteristics as predicate device | RT300-S/SP has 0-140mA charge-balanced stimulator, same as predicate. |
| Technological differences do not raise new safety/effectiveness questions | - Power source: Mains power (same as predicate) |
- Controller: Pocket PC-based custom software (different from predicate's custom controller). The safety and effectiveness of the controller has been demonstrated over its development.
- Stimulator: 0-140mA charge-balanced (same as predicate)
- Flywheel: Motorized to create flywheel effect (different from predicate's heavy mechanical flywheel). Safety and effectiveness "extensively demonstrated" by ongoing clinical use of the motorized ergometer without the stimulation component.
- Seating: Allows user to remain in their own seating (different from predicate's dedicated seating)
- Passive cycling: Utilizes motor assistance (different from predicate's manual assistance). Safety and effectiveness "extensively demonstrated" by ongoing clinical use of the motorized ergometer without the stimulation component. |
| Performance to specification (non-clinical) | System testing conducted to verify performance to specification. Specific metrics not detailed but implied by the successful testing. |
| Correct operation, including electrode off detection (clinical) | Tested on able-bodied subjects to confirm correct operation and detection of electrode off conditions with varying skin impedances. |
2. Sample Size Used for the Test Set and Data Provenance
- Able-bodied subjects: "able bodied subjects" - specific number not provided.
- Spinal cord injured subjects: "spinal cord injured subjects" - specific number not provided.
- Data Provenance: Not explicitly stated, but the submission is from a US company (Restorative Therapies Inc, Baltimore, MD), suggesting the testing likely occurred in the US. The phrase "European Infotoneous in the U.S.A." for the motorized ergometer suggests some broader context of use, but the immediate testing is not localized. It is prospective for the able-bodied and spinal cord injured subjects, as the device is being utilized or was tested for this submission.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
Not applicable. This submission is for a therapeutic device that relies on physical performance and functional equivalence rather than diagnostic interpretation requiring expert-established ground truth. The "ground truth" here is the physical function and safety of the device as tested.
4. Adjudication Method
Not applicable. See point 3.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
Not applicable. This is a therapeutic device, not an imaging or diagnostic device that would typically involve human readers for interpretation. The comparison is between the performance of the new device and a predicate device.
6. Standalone Performance Study
Yes, a standalone study of the algorithm/device performance was conducted. This includes:
- Non-clinical testing: Output characteristic measurements of the new device to confirm technical specifications and comparison to the predicate. System testing to verify performance to specification.
- Clinical testing:
- Testing with able-bodied subjects to confirm correct operation of the system, including correct detection of electrode off conditions with varying skin impedances.
- The RT300-S "is being utilized in clinical studies involving spinal cord injured subjects," indicating further evaluation of the device in its target population.
7. Type of Ground Truth Used
The "ground truth" in this context is based on:
- Technical specifications and performance standards: Non-clinical tests confirmed the device met its technical specifications and demonstrated output characteristics equivalent to the predicate.
- Observed physical operation and safety: Clinical testing on able-bodied subjects confirmed the "correct operation of the system" and safety features like electrode off detection.
- Clinical utility/ongoing use: The ongoing clinical use in spinal cord injured subjects further supports its intended function, and the "extensive demonstration" of safety and effectiveness of the motorized ergometer (without stimulation) through ongoing clinical use in Europe and the USA for the "flywheel" and "passive cycling" components.
8. Sample Size for the Training Set
Not applicable. No "training set" in the machine learning sense is mentioned or implied for this device. The development process would have involved iterative design and testing, but not a formal machine learning training set.
9. How the Ground Truth for the Training Set Was Established
Not applicable. See point 8.
§ 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).