(9 days)
The intended use of the Invacare INT /DL40i Controller is to activate and control powered wheelchair motion. Additionally, it provides a method of selecting the type of operational parameters which best suit the particular control needs of the wheelchair user.
The INT /DL40i controller is an electronic microcomputer based motor control device for power wheelchairs intended to activate and control the wheelchair motion. It also provides the means for selecting, adjusting and programming the type of wheelchair operation parameters and performance characteristics to meet the particular control needs of the wheelchair user.
The INT/DL40i controller consists of a single module that includes both the joystick and the motor controller. It has two drive modes and twelve performance adjustment settings in its program menu. Programming the controller requires the use of a separate programming device since it does not have "Through the Joystick Programming" (TTJP) capability. Also, the INT/DL40i controller does not include any additional motion control activation devices such as "Sip N Puff" or seat reclining.
This document describes the Invacare INT/DL40i Micro Computer Control for Power Wheelchairs. The submission is a Special 510(k) to allow the use of the controller on a different model of Invacare's Pronto wheelchairs, the M41, while maintaining substantial equivalence to the predicate device (K950724).
Here's an analysis of the provided information:
1. Table of Acceptance Criteria and Reported Device Performance:
The document doesn't explicitly state "acceptance criteria" in a quantitative performance metric sense (e.g., sensitivity, specificity, accuracy for an AI device). Instead, the acceptance criteria are met by demonstrating conformance to a set of recognized standards and showing that the modified device performs as intended and is substantially equivalent to the predicate device.
| Acceptance Criteria (Related to Standards/Performance) | Reported Device Performance |
|---|---|
| Intended Use: To activate and control powered wheelchair motion and provide selection of operational parameters. | Meets: The modified INT/DL40i Controller's intended use remains the same as the predicate device. |
| Electronics: Digital Based | Meets: Modified INT/DL40i is Digital Based. |
| Drive Control: Microprocessor | Meets: Modified INT/DL40i uses a Microprocessor. |
| PC Boards: Surface and Through Hole Mounted | Meets: Modified INT/DL40i uses Surface and Through Hole Mounted PC Boards. |
| Drive Modes: (Modified has 2) | Differs, but acceptable due to improved functionality: The modified device has 2 drive modes, an increase from the predicate's 1. This is considered an enhancement, not a compromise in safety or effectiveness. |
| Controller Module: Integrated with Joystick | Meets: Modified INT/DL40i is Integrated with Joystick. |
| Sip 'N' Puff Module Option: No | Meets: Modified INT/DL40i does not have this option. |
| ECU Module Option: No | Meets: Modified INT/DL40i does not have this option. |
| Recliner Module Option: No | Meets: Modified INT/DL40i does not have this option. |
| RIM Control Option: No | Meets: Modified INT/DL40i does not have this option. |
| Remote Programmer Option: Yes | Meets: Modified INT/DL40i supports Remote Programmer. |
| LCD Joystick Option: No | Meets: Modified INT/DL40i does not have this option. |
| TTJP Capability: No | Meets: Modified INT/DL40i does not have TTJP Capability. |
| Performance Adjustments: (Modified has 12) | Differs, but acceptable due to improved functionality: The modified device has 12 performance adjustments, an increase from the predicate's 6. This is considered an enhancement. |
| Enclosures: Pressure Die Cast Aluminum - Bottom, Injection Molded Polymer - Top | Differs, but acceptable: The modified device uses Pressure Die Cast Aluminum - Bottom and Injection Molded Polymer - Top, whereas the predicate used only Pressure Die Cast Aluminum. This is a design change, but the performance data concludes it performs as intended. |
| Manufacturer: Dynamic Controls, Ltd., Christchurch, New Zealand | Meets: Same manufacturer. |
| Conformance to ANSI/RESNA WC/Vols. 1&2, 1998 (Sections 1-10, 14, 21): Various standards related to stability, braking, energy consumption, dimensions, speed, strength, climatic tests, obstacle climbing, power/control, and electromagnetic compatibility. | Meets: The document implies that testing was conducted to allow the use of the controller on the M41 wheelchair, which would encompass these safety and performance aspects. The conclusion states "The performance data found in this submission shows that the INT/DL40i Controller performs as intended." |
| Conformance to CISPR 11: Industrial, Scientific and Medical (ISM) Radio Frequency Equipment-Electromagnetic Disturbance Characteristics-Limits and Methods of Measurement. | Meets: As implied by the general performance data statement. |
2. Sample size used for the test set and the data provenance:
The document does not specify a distinct "test set" in the context of an AI/ML device where data samples are used to evaluate model performance. Instead, the "testing" refers to the engineering and regulatory verification required for a medical device.
- Test Set: The testing was conducted to allow the use of the controller on a "different model of Invacare's Pronto wheelchairs, the M41". The sample size would therefore correspond to the number of M41 wheelchairs or samples tested for compliance with the listed standards. This number is not explicitly stated but would typically be a relatively small number of physical prototype devices.
- Data Provenance: Not applicable in the context of AI/ML data sets. The testing is in-house validation and verification by the manufacturer.
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. For this type of device (power wheelchair controller), "ground truth" is established through physical testing against established international and national standards (e.g., ANSI/RESNA, CISPR). The "experts" involved would be the engineers and technicians conducting the tests and interpreting the results against the standard requirements, rather than clinical experts establishing a diagnosis or outcome.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:
Not applicable. Adjudication methods like 2+1 or 3+1 are used for human expert review of clinical cases to establish ground truth for AI/ML models. For a physical device like a wheelchair controller, compliance is determined by objective measurements and tests against pre-defined specifications and standards.
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. MRMC studies are specific to AI-assisted diagnostic or interpretive devices where human performance is part of the evaluation. This device is a power wheelchair controller, not a diagnostic AI tool.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
Not applicable. This device is a physical hardware and software control unit for a wheelchair. Its operation is inherently "standalone" in the sense that the controller executes commands based on user input, but it's not an algorithm that produces interpretations or diagnoses independently.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
The "ground truth" for this device's performance is objective compliance with the specified international and national physical performance and safety standards, such as:
- ANSI/RESNA WC/Vols. 1&2, 1998 (Sections 1-10, 14, 21), covering aspects like stability, braking, energy consumption, dimensions, speed, strength, climatic performance, obstacle climbing, power/control systems, and electromagnetic compatibility.
- CISPR 11 (Electromagnetic Disturbance Characteristics).
8. The sample size for the training set:
Not applicable. This device is not an AI/ML model that requires a "training set." It is a traditional embedded control system.
9. How the ground truth for the training set was established:
Not applicable, as 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).