(408 days)
The ExoAtlet-II is intended to perform ambulatory functions in rehabilitation under the supervision of a trained physical therapist for the following population with upper extremity motor function at least 4/5 in both arms:
· Individuals with spinal cord injuries at levels T4 to L5
- · Individuals with spinal cord injuries at levels of C7 to T3 (ASIA D)
The therapist must complete a training program prior to use of the device.
The device is not intended for sports or stair climbing.
The ExoAtlet-II is intended to perform ambulatory functions in rehabilitation institutions, hospitals, or similar institutions under the supervision of a healthcare professional (HCP) such as a trained physical therapist. The ExoAtlet-II is indicated for individuals with spinal cord injuries at levels T4-L5 and individuals with spinal cord injuries at levels of C7-T3. All users must have upper extremity motor function of at least 4/5 in both arms. The ExoAtlet-II is intended for multiple users in a clinical setting (i.e., gait lab or rehabilitation center) under supervision. The ExoAtlet-II includes a battery powered exoskeleton, an ExoCrutch, and a Tablet PC.
ExoAtlet-II is designed to be operated with a trained physical therapist who has received preliminary training on the Exoskeleton operation. This therapist will be familiar with the rules of the use and operational documentation. Training is conducted in a designated medical facility that is representative of the indicated environments (e.g., hospital, outpatient physical therapy clinic or similar). The training identifies safe environments of device use and uses all of the safety features found in the subject device. The training manual will be provided with the user manual along with a trainee itinerary and a trainee certification exam. The trainee needs to pass 80% of the exam questions to obtain certification.
Here's a breakdown of the acceptance criteria and study information for the ExoAtlet-II device based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a table of acceptance criteria with corresponding performance metrics. Instead, it describes general performance characteristics and notes differences from the predicate device that were evaluated for safety and effectiveness through testing.
However, based on the "Comparison of Technological Characteristics" table and the "Summary of Clinical Testing" section, we can infer some key performance aspects and their reported outcomes:
| Feature/Metric | Acceptance Criteria (Inferred from Predicate/Safety Evaluation) | Reported Device Performance (ExoAtlet-II) |
|---|---|---|
| Indications for Use | Safe and effective for specified SCI populations. | Intended for individuals with spinal cord injuries at T4-L5 and C7-T3 (ASIA D) with 4/5 upper extremity motor function. |
| Mobility Ability | Sit, Stand, Walk, Turn (predicate) | Sit, Stand, Walk (turning capability not included, evaluated via clinical testing). |
| Walking Speed | ~2 km/hr (predicate) | 1.5 km/hr (slightly slower, evaluated via clinical testing, does not pose increased safety risk). |
| Grade of Inclination | 1.15° (predicate) | 0-5° (greater inclination, evaluated via clinical testing for safety). |
| Range of Motion | Hips: 135° flex to 20° ext; Knees: 130° flex to 0° ext; Ankles: 10° flex to 10° ext (predicate) | Hips: 108° flex to 21° ext; Knees: 112° flex to 2° ext; Ankles: 15° flex to 0-15° ext (larger range, evaluated via clinical testing for safety/effectiveness). |
| Crutch Use | Safe and effective | Evaluated in compliance with ISO 11334-1:2007. |
| Failsafe Feature | Safely manage failure event | Knees and pelvis become locked (different from predicate, evaluated via clinical testing for safety). |
| Electrical Safety | Compliance with IEC 60601-1 | Complies with IEC 60601-1:2005, COR1:2006, COR2:2007, AMD1: 2012. |
| EMC Compatibility | Compliance with IEC 60601-1-2 | Complies with IEC 60601-1-2: 2014. |
| Software Integrity | Compliance with IEC 62304 | Complies with IEC 62304:2006. |
| Battery Safety/Performance | Safe, functional battery | Tested in compliance with IEC 62133: 2012. 4 hours continuous usage, 4 hours charge time. Evaluated electrical safety, EMC, and clinical testing. |
| Durability | Expected life comparable to predicate | 5 years (longer than predicate's 4 years), evaluated via durability testing. |
| 10 Meter Walk Test | Successful completion | 19 of 20 subjects successfully completed. |
| 6-Minute Walk Test (6 MWT) | Successful completion | 19 of 20 subjects successfully completed (1 unable due to physical fitness). |
| User Comfort Survey | Positive user experience | 18 of 20 subjects rated comfort 8-10 out of 10; 2 subjects rated 6 out of 10. |
| Skin Assessment (AEs) | No adverse events related to biocompatibility | None found (abrasions, dry flaky skin, cuts, eschar, rash) before, during, or after use. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size (Clinical Study): 20 subjects (n=20)
- Data Provenance: The study was described as an "open label, non-randomized clinical study." The document does not specify the country of origin but implies it was internal to ExoAtlet given "ExoAtlet conducted an... clinical study." The study is prospective as it was conducted to assess the safety and effectiveness of the device.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not mention the use of experts to establish a "ground truth" for a test set in the traditional sense of diagnostic accuracy. Instead, the clinical study involved subjects using the device under the supervision of a "trained physical therapist." The therapist's role is to supervise, and their training and certification are mentioned as a requirement for device use. The study monitors objective performance (walk tests) and subjective feedback (comfort surveys, skin assessments) directly from the subjects and observations.
4. Adjudication Method for the Test Set
Not applicable. The clinical study described is a performance and safety study involving a device for rehabilitation, not a diagnostic study requiring adjudication of expert interpretations for ground truth.
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 is not an AI-assisted diagnostic device, but a powered exoskeleton for rehabilitation. Therefore, an MRMC study and effects on human reader performance are not relevant.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
Not applicable. The ExoAtlet-II is a physical device intended to be used by individuals under the supervision of a trained physical therapist. It is inherently a "human-in-the-loop" device by design and intended use. There is no mention of a standalone algorithm performance test.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
The clinical study assessed the device's safety and effectiveness directly through:
- Performance metrics: Successful completion of the 10 Meter Walk Test and 6-Minute Walk Test.
- User feedback: Comfort ratings via surveys.
- Medical observation: Skin assessments for adverse events.
- Overall safety and functionality: Absence of new safety issues or ineffectiveness compared to predicates.
These are direct measures of the device's functional performance and user impact, rather than a "ground truth" established through external pathological or expert consensus for a diagnostic task.
8. The Sample Size for the Training Set
The document does not provide information about a "training set" in the context of machine learning or AI. The training described is for the human therapist who uses the device.
- Training for Therapists: Not a "training set" for the device's algorithm, but a program for healthcare professionals. The therapist completes a training program and must pass 80% of an exam for certification.
9. How the Ground Truth for the Training Set Was Established
As noted above, there is no AI/ML training set mentioned. The "training set" for therapists involves instructions, operational documentation, and an exam, but this is human training, not algorithm training data.
§ 890.3480 Powered lower extremity exoskeleton.
(a)
Identification. A powered lower extremity exoskeleton is a prescription device that is composed of an external, powered, motorized orthosis that is placed over a person's paralyzed or weakened limbs for medical purposes.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Elements of the device materials that may contact the patient must be demonstrated to be biocompatible.
(2) Appropriate analysis/testing must validate electromagnetic compatibility/interference (EMC/EMI), electrical safety, thermal safety, mechanical safety, battery performance and safety, and wireless performance, if applicable.
(3) Appropriate software verification, validation, and hazard analysis must be performed.
(4) Design characteristics must ensure geometry and materials composition are consistent with intended use.
(5) Non-clinical performance testing must demonstrate that the device performs as intended under anticipated conditions of use. Performance testing must include:
(i) Mechanical bench testing (including durability testing) to demonstrate that the device will withstand forces, conditions, and environments encountered during use;
(ii) Simulated use testing (
i.e., cyclic loading testing) to demonstrate performance of device commands and safeguard under worst case conditions and after durability testing;(iii) Verification and validation of manual override controls are necessary, if present;
(iv) The accuracy of device features and safeguards; and
(v) Device functionality in terms of flame retardant materials, liquid/particle ingress prevention, sensor and actuator performance, and motor performance.
(6) Clinical testing must demonstrate a reasonable assurance of safe and effective use and capture any adverse events observed during clinical use when used under the proposed conditions of use, which must include considerations for:
(i) Level of supervision necessary, and
(ii) Environment of use (
e.g., indoors and/or outdoors) including obstacles and terrain representative of the intended use environment.(7) A training program must be included with sufficient educational elements so that upon completion of training program, the clinician, user, and companion can:
(i) Identify the safe environments for device use,
(ii) Use all safety features of device, and
(iii) Operate the device in simulated or actual use environments representative of indicated environments and use.
(8) Labeling for the Physician and User must include the following:
(i) Appropriate instructions, warning, cautions, limitations, and information related to the necessary safeguards of the device, including warning against activities and environments that may put the user at greater risk.
(ii) Specific instructions and the clinical training needed for the safe use of the device, which includes:
(A) Instructions on assembling the device in all available configurations;
(B) Instructions on fitting the patient;
(C) Instructions and explanations of all available programs and how to program the device;
(D) Instructions and explanation of all controls, input, and outputs;
(E) Instructions on all available modes or states of the device;
(F) Instructions on all safety features of the device; and
(G) Instructions for properly maintaining the device.
(iii) Information on the patient population for which the device has been demonstrated to have a reasonable assurance of safety and effectiveness.
(iv) Pertinent non-clinical testing information (
e.g., EMC, battery longevity).(v) A detailed summary of the clinical testing including:
(A) Adverse events encountered under use conditions,
(B) Summary of study outcomes and endpoints, and
(C) Information pertinent to use of the device including the conditions under which the device was studied (
e.g., level of supervision or assistance, and environment of use (e.g., indoors and/or outdoors) including obstacles and terrain).