K Number
K023852
Date Cleared
2003-03-04

(105 days)

Product Code
Regulation Number
890.5150
Panel
PM
Reference & Predicate Devices
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP AuthorizedThirdpartyExpeditedreview
Intended Use

The product will be used by patients to assist in navigating a specific set of stairs. This is a selfcontained product that is mounted to the tread of a staircase. A trained dealer will install the unit, test it and teach the end user how to operate it. The typical user is someone who has limited function of their knees, hips or ankles and/or has trouble bending these joints. Other users include rehabilitated stroke victims, those inflicted with MS, arthritis, heart disease, and those who cannot handle the exertion of walking up and down stairs. Doctors or physical therapists may recommend the unit for those who are recuperating, but a large number of users acquire a stairway elevator just because it eases the burden of climbing stairs, improving their quality of life. For those who are wheelchair bound, it requires that they be able to transfer and is usually an option only if the physical limitations of the residence prohibits a vertical elevator.

Device Description

The Stairfriend is a curved stairway chairlift designed to carry a rated load of 300 lb. directly up and down a set of stairs in a residence. The Stairfriend is designed to travel a maximum 30 feet at a rated speed of 16 feet per minute. Safety switches installed on the Stairfriend stop the carriage when it reaches the top or bottom of the stairway. The footrest incorporates obstruction sensors, which will stop the carriage if an obstacle is encountered on the stairs. Standard equipment includes: Rack and pinion drive, Dynamic motor braking and self-locking gearbox, 2" (51 mm) rigid double square tube rail construction, Inside and outside radius curve capabilities, Spiral and flat landing configurations, Support posts anchored to stair treads (no wall required), 300 lb (136 kg) capacity, Battery-powered 24 vdc motor, Pair of 12-volt, maintenance-free batteries, Charger to be plugged in at top or bottom landing 110 vac, 15 amp, 60 hz outlet, Electronic controller with soft start, Fused control circuit, Wireless call-send controls at both landings, Continuous pressure buttons, No rail overhang at top landing, Foldable footrest, seat and padded armrest, Seat that swivels and locks in 60° and 90° positions in both directions, Seatbelt, Seat swivel safety switch, Obstacle sensor.

AI/ML Overview

The provided document does not contain information about acceptance criteria or a study proving the device meets them. The document is a 510(k) premarket notification for the "Stairfriend" Curved Stairway Chairlift, indicating a determination of substantial equivalence to a predicate device.

The 510(k) process primarily focuses on demonstrating that a new device is as safe and effective as a legally marketed predicate device, rather than requiring extensive clinical trials or performance studies against specific acceptance criteria like those outlined in your request. The document mentions that both the subject device and the predicate device "have been designed and engineered to meet and exceed the safety standards CSA-B355 -- 'Lifts for persons with physical disabilities' and ASME A17.1 part XX and part XXI 'Safety Code for Elevators and Escalators'." However, no specific performance data or a study demonstrating adherence to these standards is included.

Therefore, I cannot provide the requested information based on the given input.

To answer your specific points, based only on the provided text:

  1. A table of acceptance criteria and the reported device performance: Not provided.
  2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective): Not provided. This type of information is typically not included in a 510(k) for devices like a chairlift, which are evaluated against engineering standards rather than clinical performance data with human subjects.
  3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience): Not applicable/Not provided. The ground truth concept, typically involving expert consensus or pathology for diagnostic devices, is not relevant to this type of mechanical aid.
  4. Adjudication method (e.g. 2+1, 3+1, none) for the test set: Not applicable/Not provided.
  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 chairlift, not an AI-powered diagnostic device.
  6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done: Not applicable. No algorithm is mentioned.
  7. The type of ground truth used (expert consensus, pathology, outcomes data, etc): Not applicable.
  8. The sample size for the training set: Not applicable. No training set is mentioned as this is not an AI/machine learning device.
  9. How the ground truth for the training set was established: Not applicable.

§ 890.5150 Powered patient transport.

(a)
Powered patient stairway chair lifts —(1)Identification. A powered patient stairway chair lift is a motorized lift equipped with a seat and permanently mounted in one location that is intended for use in mitigating mobility impairment caused by injury or other disease by moving a person up and down a stairway.(2)
Classification. Class II. The stairway chair lift 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:(i) Appropriate analysis and nonclinical testing (such as that outlined in the currently FDA-recognized edition of American Society of Mechanical Engineers (ASME) A18.1 “Safety Standard for Platform Lifts and Stairway Chair Lifts”) must demonstrate that the safety controls are adequate to prevent a free fall of the chair in the event of a device failure;
(ii) Appropriate analysis and nonclinical testing must demonstrate the ability of the device, including armrests, to withstand the rated load with an appropriate factor of safety;
(iii) Appropriate restraints must be provided to prevent the user from falling from the device (such as that outlined in the currently FDA-recognized edition of ASME A18.1 “Safety Standard for Platform Lifts and Stairway Chair Lifts”);
(iv) Appropriate analysis and nonclinical testing (such as that outlined in the currently FDA-recognized editions of AAMI/ANSI/IEC 60601-1-2, “Medical Electrical Equipment—Part 1-2: General Requirements for Safety—Collateral Standard: Electromagnetic Compatibility—Requirements and Tests,” and ASME A18.1 “Safety Standard for Platform Lifts and Stairway Chair Lifts”) must validate electromagnetic compatibility and electrical safety; and
(v) Appropriate analysis and nonclinical testing must demonstrate the resistance of the device upholstery to ignition.
(b)
All other powered patient transport —(1)Identification. A powered patient transport is a motorized device intended for use in mitigating mobility impairment caused by injury or other disease by moving a person from one location or level to another, such as up and down flights of stairs (e.g., attendant-operated portable stair-climbing chairs). This generic type of device does not include motorized three-wheeled vehicles or wheelchairs.(2)
Classification. Class II.