(154 days)
The ZX-1 is intended to provide enhanced mobility to disabled persons who are capable of operating a powered and manual wheelchair, by providing powered mobility to manual wheelchairs.
The ZX-1 Power Add On is a light duty, power add-on device with the purpose of delivering powered mobility to a manual wheelchair. The device easily attaches/detaches to the frame of a manual wheelchair. The engagement between the ZX-1 and the manual wheelchair is accomplished without the need for hardware or other fixed attachment devices. The user remains seated in their manual wheelchair and performs a simple maneuver to attach the ZX-1 to their manual wheelchair. Once securely attached to the ZX-1, the user negotiates the speed and direction of their wheelchair by using a VR2 joystick controller attached to the arm rest of the ZX-1. The device consists primarily of a stainless steel base with drive wheels, a power module with joystick, two drive motors, a connector mechanism, two armrests and an anti-tilt assembly. It functions by connecting to the host manual wheelchair rear camber tube. Once the connection is made, the linear actuator lifts the manual wheelchair rear wheels slightly off the ground and onto the stainless steel base with drive wheels. Power to the drive motors is supplied by use of the joystick which is used to engage wheelchair motion and steer the chair. During use, the ZX-1 offers forward, reverse and 360 degree turning maneuverability. The user is able to adjust the speed setting to meet their needs and level of comfort.
The provided text describes the Spinergy ZX-1 Power Add On, a device designed to provide powered mobility to manual wheelchairs. The document is a 510(k) summary, demonstrating substantial equivalence to a predicate device.
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:
The document primarily focuses on demonstrating substantial equivalence to a predicate device (Albers E-Fix Conversion Kit - K943789) and adherence to recognized standards. The "acceptance criteria" are not explicitly listed in a separate table as pass/fail thresholds, but are instead derived from the performance specifications of the predicate device and relevant industry standards.
| Acceptance Criteria (Inferred from Predicate Device & Standards) | Reported Device Performance (Spinergy ZX-1 Power Add On) |
|---|---|
| Intended Use/Indications for Use: Provide powered mobility to manual wheelchairs for disabled persons capable of operation. | Met: "The ZX-1 is intended to provide enhanced mobility to disabled persons who are capable of operating a powered and manual wheelchair, by providing powered mobility to manual wheelchairs." (Page 3, 4, 8) |
| Maximum Speed: (Predicate: 3.7 mph) | Met (with minor difference): Maximum speed 3.2 mph. (Page 2). (Discussion indicates minor difference of .5mph is negligible - Page 4) |
| Maximum Patient Weight Capacity: (Predicate: 250 lbs) | Met: Maximum patient weight capacity is 250 lbs. (Page 2, 4) |
| Maximum Operation Incline: (Not explicitly stated for predicate) | Met: Maximum operation incline 6 degrees. (Page 2) |
| Curb Clearance: (Not explicitly stated for predicate) | Met: Highest curb clearance 2 inches (50mm). (Page 2) |
| Electromagnetic Compatibility (EMC): Adherence to relevant standards. | Met: Tested in accordance with EN55011/A2:2007, IEC 60601-1-2:2007 (Modified) and American National Standard: Requirements and Test Methods for Electromagnetic Compatibility of Electrically Powered Wheelchairs and Motorized Scooters RESNA WC-2:2009 Standard Section 21. (Page 3) |
| Leakage Current: Less than 100 Amp maximum value. | Met: Results confirm that leakage current is less than the 100 Amp maximum value specified in the Powered Wheelchair and Scooter 510(k) Guidance Document. (Page 3) |
| General Performance & Safety: Adherence to RESNA and ISO standards for wheelchairs. | Met: Tested to and meets the requirements specified in the Rehabilitation Engineering Society of North America (RESNA) Standard ANSI/RESNA WC/14 (1991) and ISO Standard ISO 7176: 1993(E), "ISO Standard, Wheelchairs -Requirements and Test Methods for the Power and Control Systems of Electric Wheelchairs." (Page 3) |
| Basic Electro-mechanical Drive Technology: (Similar to predicate) | Met: Incorporates basic electro-mechanical drive technology, two drive motors and basic gear reduction, microprocessor-based motor controller, 24 VDC operating voltage. (Page 2, 4) |
| Power Source: Two 12 VDC batteries. | Met: Powered by two 12VDC batteries. (Page 2, 4) |
| Joystick Control: Engage motion and steer the chair. | Met: Joystick control to engage motion and steer the chair. (Page 2, 4) |
| Free Wheel Mode: Allows manual movement when attached. | Met: Free Wheel Mode which disables the drive motors and allows the device to be attendant propelled when the power-conversion device is attached. (Page 4) |
| Braking Mechanism: Effective and safe braking. | Met: Electromagnetic braking system and disk park brake. (Page 5, discussed as similar in function to predicate's two braking systems) |
| Battery Level Indicator: | Met: Battery level indicator. (Page 4). The ZX-1 battery indicator flashes red when the batteries are near depletion. (Page 5) |
2. Sample Size Used for the Test Set and Data Provenance:
The document does not specify a "sample size" in the context of user testing or a clinical trial for the ZX-1 Power Add On. The testing described is non-clinical performance testing of the device itself and its components against established engineering standards. Therefore, there's no "test set" of individuals or patient data. The provenance of the data is from Spinergy's own internal testing in accordance with recognized international and national standards.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications:
Not applicable. This was non-clinical engineering and electrical safety testing against established standards, not a study requiring expert clinical assessment for ground truth.
4. Adjudication Method for the Test Set:
Not applicable. The testing described is objective measurement against defined technical standards, not a subjective assessment requiring adjudication.
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 a medical device (power add-on for wheelchairs), not an AI diagnostic or assistance tool for human interpretation.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done:
Not applicable. This is a mechanical/electrical device used by a human operator, not an algorithm.
7. The Type of Ground Truth Used:
The "ground truth" for the performance claims of the ZX-1 Power Add On are the requirements and test methods specified in the Rehabilitation Engineering Society of North America (RESNA) Standard ANSI/RESNA WC/14 (1991), ISO Standard ISO 7176: 1993(E), IEC 60601-1 Standard for Medical Equipment, and EN55011/A2:2007, IEC 60601-1-2:2007, and RESNA WC-2:2009 Standard Section 21. These are objective, internationally recognized standards for wheelchair safety and performance.
8. The Sample Size for the Training Set:
Not applicable. This is a physical device, not an AI model that requires a training set.
9. How the Ground Truth for the Training Set Was Established:
Not applicable. There is no training set for this type of device.
§ 890.3860 Powered wheelchair.
(a)
Identification. A powered wheelchair is a battery-operated device with wheels that is intended for medical purposes to provide mobility to persons restricted to a sitting position.(b)
Classification. Class II (performance standards).