(188 days)
The clinical treatment of persons in wheelchairs presents a significant issue for the clinician. Treatments related to a patient's head often require them to be reclined. The platform allows for reclining the wheelchair giving full support to both patient and clinician. The hazards associated with transfers to other couches or chairs are eliminated. Typical treatments would include: Dental, Maxiliofacial work, Ear, Nose and Throat procedures, Eye treatments and surgery, Podiatry.
The Compact Wheelchair Platform (CWP) is designed to assist in the clinical treatment of wheelchair users by providing a convenient wheelchair accessible platform that can be tilted so that the head is placed in the optimum position of comfort for both staff and patient. It is a direct development of the Mobile Wheelchair Platform (K073565). The complete redesign more than halved the storage area and up-graded the load from a SWL of 594lb to 825lbs. The angle of tilt has been altered to 60deg to provide a recovery position. The Wheelchair platform is supported on two side frames with a high pivot point. The hydraulic cylinders are below the pivot and retract to tilt the platform. This gives a very compact form and with a hinged platform base the whole unit is no more than 24" wide. It can be easily moved through doors for sharing with other opertories. The whole construction is aerospace high strength aluminium alloys or stainless steel giving a high strength weight ratio. The unit is powered at 24v. The main source of power is from a pair of 12v lead acid batteries that can be easily replaced and last for at least 40 full cycles before needing to be recharged. A dc supply is provided to operate the machine from the mains supply if needed. The control is via a PCB with a PIC logic controller. All switching takes place at 5v and makes the controls light and reliable. The logic capability allows continuous monitoring of safety switching and the integration of good safety procedures. A radio handset is normally used to control the platform eliminating any trailing wires. Safety is a major concern and entrapment is eliminated by using sensitive, fail-safe, strip switches at all sensitive points on the mechanism. The radio handset and fixed switches on the machine are supplied to operate the device, duplicating the control function. All control and drive elements are housed safely under a cover. The machine has clean lines and is easily cleaned with wipe over surfaces.
Here's an analysis of the provided text regarding the acceptance criteria and study for the "Compact Wheelchair Platform":
The provided document is a 510(k) submission summary for a medical device called the "Compact Wheelchair Platform" (CWP). It primarily focuses on demonstrating substantial equivalence to a previously cleared device, the "Mobile Wheelchair Platform" (K073565). Crucially, the document does not describe a clinical study with a test set, ground truth, or expert involvement as one would typically expect for performance evaluation in the context of diagnostic or AI-driven devices.
Instead, the "acceptance criteria" can be inferred from the technical characteristics and improvements made over the predicate device, and the "study" is more akin to a design and engineering validation against established safety and performance standards for this type of medical equipment.
1. Table of Acceptance Criteria and Reported Device Performance
| Characteristic / Acceptance Criteria (Derived) | Reported Device Performance (Compact Wheelchair Platform) |
|---|---|
| Structural Material: Improved over steel fabrication | Aluminium and Stainless steel (Aerospace high strength) |
| Drive Mechanism: Improved over electrical linear | Hydraulic operation (allows compact form) |
| Power Source: Maintain 24V battery/mains | Battery 24v and Power supply delivering 24v (40 full cycles before recharge) |
| Backrest Support: Adjustable height over fixed height | Pivots in and out, adjustable by worm and wheel. Adjustable height backrest pad |
| Headrest: Maintain adjustable support | Adjustable using a slotted arm with an adjustable headrest cushion for neck and head support |
| Wheelchair Type Compatibility: All types | All types including battery driven wheelchairs and specially moulded chairs |
| Command Input: Maintain remote and fixed switches | Fixed switches on the mechanism cover and remote radio transmitter handset |
| Foot Crush Protection: Maintain safety features | Pressure sensitive strip switches (fail-safe at all sensitive points) |
| Max. Angle of Tilt: Increased over 45 degrees | 60 degrees (provides recovery position; clinicians can still opt for smaller angles) |
| Rated Capacity (SWL): Increased over 594lb | 660lb (BSEN1570:1999) - Note: The description mentions an upgrade to 825lbs but the table states 660lb. |
| Storage Area: Reduced from predicate | More than halved the storage area (vs. Mobile Wheelchair Platform) |
| Lightness: Lighter than predicate | Lighter platform (implied by "smaller lighter platform" and aluminium/stainless steel construction) |
| Maneuverability: Easily moved through doors | No more than 24" wide; easily moved through doors for sharing with other opertories |
| Safety - Entrapment: Eliminated | Eliminated by using sensitive, fail-safe, strip switches at all sensitive points on the mechanism. |
| Control Reliability: Light and reliable controls | All switching at 5v via PCB with PIC logic controller; continuous monitoring of safety switching. |
| Power Endurance: >40 cycles without recharge | Last for at least 40 full cycles before needing to be recharged |
| Optimal Clinician Operating Position | Optimal height at 45 degrees tilt (800mm); clinical stool can optimize seating position if desired for smaller angles. |
2. Sample Size Used for the Test Set and Data Provenance
- None. This document does not describe a clinical study with a "test set" in the context of data analysis or machine learning. The evaluation is for a physical medical device. The "performance" assessment is based on engineering specifications, design improvements, and adherence to safety standards.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Not applicable. There is no "ground truth" established by experts for a test set in the way you'd expect for a diagnostic device. The "ground truth" for this device's performance is derived from engineering standards, user feedback (clinical feedback), and the physical testing of the device against its specifications (e.g., load capacity).
4. Adjudication Method for the Test Set
- Not applicable. No test set or expert adjudication process is described.
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 device is a mechanical patient positioning platform, not an imaging or diagnostic AI device. Therefore, no MRMC study or assessment of human reader improvement with AI assistance was performed.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Not applicable. No algorithms are described as operating in a standalone capacity that would require such testing. The device has a PIC logic controller for safety and control, but this is an embedded system, not a standalone AI application.
7. The Type of Ground Truth Used
- The "ground truth" for this device's safety and performance is based on:
- Engineering Specifications and Standards: "Rated capacity 660lb (BSEN1570:1999)" is an example, indicating adherence to an established standard.
- Clinical Feedback/User Experience: "By utilising extensive clinical feedback Design Specific has been able to develop a backrest assembly..." indicates user input informed design changes.
- Physical Testing/Validation: Implicit in meeting load capacities, tilt angles, and safety features like entrapment elimination.
- Substantial Equivalence: The primary "ground truth" for FDA clearance is demonstrating that the new device is as safe and effective as a legally marketed predicate device.
8. The Sample Size for the Training Set
- Not applicable. There is no "training set" in the context of machine learning. The design improvements were based on "extensive clinical feedback" (qualitative data from users) and engineering principles.
9. How the Ground Truth for the Training Set was Established
- Not applicable. As there is no training set as defined for AI or statistical modeling, this question does not apply. The evolution of the design, however, was informed by:
- User feedback: "users expressed a need for a smaller lighter platform that would require a Timuse" and "The increase in body mass of the general population required that the new platform should be able to carry higher loads."
- Clinical consultation: "By utilising extensive clinical feedback Design Specific has been able to develop a backrest assembly..."
In summary: The provided text is a 510(k) summary for a physical medical device, not a diagnostic tool or AI-driven system. Therefore, the concepts of "acceptance criteria," "test set," "ground truth," and "expert adjudication" are interpreted through an engineering and regulatory lens, rather than a clinical study or AI performance evaluation framework. The primary "study" demonstrated how the new "Compact Wheelchair Platform" is substantially equivalent to a predicate device and incorporates improvements based on user feedback and adherence to relevant safety and performance standards.
§ 890.3110 Electric positioning chair.
(a)
Identification. An electric positioning chair is a device with a motorized positioning control that is intended for medical purposes and that can be adjusted to various positions. The device is used to provide stability for patients with athetosis (involuntary spasms) and to alter postural positions.(b)
Classification. Class II. The electric positioning chair is exempt from premarket notification procedures in subpart E of part 807 of this chapter, subject to § 890.9 and the following conditions for exemption:(1) Appropriate analysis and non-clinical testing must demonstrate that the safety controls are adequate to ensure safe use of the device and prevent user falls from the device in the event of a device failure;
(2) Appropriate analysis and non-clinical testing must demonstrate the ability of the device to withstand the rated user weight load with an appropriate factor of safety;
(3) Appropriate analysis and non-clinical testing must demonstrate the longevity of the device to withstand external forces applied to the device and provide the user with an expected service life of the device;
(4) Appropriate analysis and non-clinical testing must demonstrate proper environments of use and storage of the device to maximize the longevity of the device;
(5) Appropriate analysis and non-clinical testing (such as that outlined in the currently FDA-recognized editions of ANSI/AAMI/ES60601-1, “Medical Electrical Equipment—Part 1: General Requirements for Basic Safety and Essential Performance,” and ANSI/AAMI/IEC 60601-1-2, “Medical Electrical Equipment—Part 1-2: General Requirements for Basic Safety and Essential Performance—Collateral Standard: Electromagnetic Disturbances—Requirements and Tests”) must validate electromagnetic compatibility and electrical safety;
(6) Appropriate analysis and non-clinical testing (such as that outlined in the currently FDA-recognized editions of ANSI/AAMI/ISO 10993-1, “Biological Evaluation of Medical Devices—Part 1: Evaluation and Testing Within a Risk Management Process,” ANSI/AAMI/ISO 10993-5, “Biological Evaluation of Medical Devices—Part 5: Tests for In Vitro Cytotoxicity,” and ANSI/AAMI/ISO 10993-10, “Biological Evaluation of Medical Devices—Part 10: Tests for Irritation and Skin Sensitization”) must validate that the skin-contacting components of the device are biocompatible;
(7) Appropriate analysis and non-clinical testing (such as that outlined in the currently FDA-recognized editions of IEC 62304, “Medical Device Software—Software Life Cycle Processes”) must validate the software life cycle and that all processes, activities, and tasks are implemented and documented;
(8) Appropriate analysis and non-clinical testing must validate that the device components are found to be non-flammable;
(9) Appropriate analysis and non-clinical testing must validate that the battery in the device (if applicable) performs as intended over the anticipated service life of the device; and
(10) Adequate patient labeling is provided to the user to document proper use and maintenance of the device to ensure safe use of the device by the patient in the intended use environment.