(52 days)
Wheelchair mobility, either self-propelled or propelled by an attendant, for the physically impaired.
The wheelchair is a standard lightweight manual folding chair that provides mobility based on an individual user's needs and capabilities. Since it has the same intended use as typical wheelchairs, its features are also comparable. A sling seat and backrest are affixed to a sturdy frame that is supported by two large rear wheels and two forward swivel caster wheels. The two side frames are connected by a horizontal cross brace, rather than a vertical cross brace, that can assume a folded configuration. The wheelchair accommodates removable armrests, detachable footrests, rear anti-tippers, push handles, and wheel locks.
The ActivX Wheelchair is a standard lightweight manual folding chair. The manufacturer, Adorno/Rogers Technology, Inc. (A/RT), claims that its device is substantially equivalent to the Quickie2 (K890050) wheelchair. The primary difference is the ActivX's horizontal cross brace, which allows for a different folding mechanism.
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criterion | Reported Device Performance |
|---|---|
| Mechanical Durability (related to folding mechanism) | Performed acceptably in the ANSI/RESNA two-drum test. |
| User Safety/Functionality | Subject evaluations supported substantial equivalence. |
| Dimensions, Construction Materials, Standard Features/Options | Substantially equivalent to the predicate device. |
| Intended Use | Identical to the predicate device (wheelchair mobility for the physically impaired). |
| Propulsion/Maneuvering | Identical to the predicate device in how the user propels and maneuvers the chair. |
2. Sample Size Used for the Test Set and Data Provenance
The document explicitly mentions "subject evaluations" but does not specify the sample size of these subjects. It also doesn't indicate the country of origin for this data or whether it was retrospective or prospective.
3. Number of Experts Used to Establish Ground Truth and Qualifications
The document does not provide details on the number or qualifications of experts used for the "subject evaluations."
4. Adjudication Method for the Test Set
The document does not describe any specific adjudication method (e.g., 2+1, 3+1, none) for the subject evaluations.
5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was mentioned. The study focused on the ActivX's performance against a standard, not on comparing human readers' improvement with or without AI assistance.
6. Standalone Performance Study
Yes, a standalone study was performed. The "Design Validation/Verification" included the ANSI/RESNA two-drum test and subject evaluations, which assessed the device's performance independently.
7. Type of Ground Truth Used
The ground truth appears to be a combination of:
- Performance Standards: The ANSI/RESNA two-drum test provides an objective, standardized measure of mechanical durability.
- User Feedback/Subjective Evaluation: "Subject evaluations" indicate that users tested the device and their feedback was part of the assessment.
8. Sample Size for the Training Set
The document does not mention any training set or related sample size. This is a medical device, not an AI/ML product, so a training set in the typical AI sense would not apply.
9. How Ground Truth for the Training Set Was Established
As there is no mention of a training set, the establishment of ground truth for such a set is not applicable.
§ 890.3850 Mechanical wheelchair.
(a)
Identification. A mechanical wheelchair is a manually operated device with wheels that is intended for medical purposes to provide mobility to persons restricted to a sitting position.(b)
Classification. Class I (general controls).