Assistive device term requests - analysis

[hoganwr]

The Pitt team requested the following assistive device terms:

Assistive devices

• Wheelchair (w/c)
• Wheeled Walker (ww)
• Rollator
• Hemi-walker
• Single Point Cane (SPC)
• Quad Cane
• Sliding board
• Hoyer lift
• Sock aid
• Reacher
• Dressing Stick
• Shoe Horn
• Long Handled Shoe Horn

[hoganwr]

These are all medical devices except possibly the reacher
NCIT does not put them (all) under medical device, but wheelchairs (which NCIT does not have under its “Medical Device”) for example, do require FDA approval and thus are indeed medical devices
Suggested hierarchy
medical device

• activity of daily living assistive device
  • locomotion assistive device
    • wheelchair
    • wheeled walker
    • rollator
    • hemi-walker
    • single point cane
    • quad cane
    • sliding board
  • dressing assistive device (aka assistive device for putting on or removing clothing)
    • sock aid
    • shoe horn
      • long-handled shoe horn
  • grasping or holding assistive device
    • medical reacher device

Note the OBO guidance for using / reusing NCIT:
Use of NCIt terms - If an ontology developer wishes to create a term with a label that already exists in NCIt, the following apply:
• If the NCIt term definition and hierarchical position are reasonable, that term SHOULD be used instead;
• If either the NCIt term definition or the hierarchical position are sub-optimal, the developer MAY create a term in the ontology with an identical label but with a revised definition and subclassing; alternatively such a term MAY be requested of another ontology, if appropriate;
• For case (b), if the definition is based on the NCIt definition, the new term MUST be linked to the original NCIt term to conform to the NCIt license requirements. Note: this does not apply to reuse of term labels.

Given this guidance and the fact we need to change the NCIT parent, we will create our own classes, hierarchy, and definitions. We can largely reuse the NCIT definitions with adaptations for Aristotelian form (and follow the guidance to link the term to the NCIT original. That guidance does not specify things sufficiently, so we will just use the following annotation property: http://www.geneontology.org/formats/oboInOwl#hasDbXref
With value NCIT: Typically this makes a clickable link in Protégé )

We can create “medical device” as a subclass of COB’s “device”. We can get COB’s “device” from an OBI import – see how it’s done in DrOn and OMRSE although perhaps there is no OBI import in REHABO yet.

We don’t need device’s parent, we’ll just put it under BFO material entity for now

medical reacher device and not just reacher device, because not all reachers are medical devices under FDA oversight. In the context of therapy, I suppose it’s still possible they are using general purpose reachers not under any FDA oversight (not even class 1 devices), but for now this will suit our purposes. In hospital settings they're likely to be FDA classified, but in private outpatient therapy settings, you're much more likely to see generic reachers sold for example at Walmart.

[manojniwas]

I agree with the proposed hierarchy — grouping into locomotion, dressing, and grasping assistive devices makes good sense clinically and ontologically. I checked rehabo-edit.owl and confirmed that REHABO currently has no OBI import. Given that the plan is to create medical device as a subclass of COB's device, could you advise on the best way to bring in the COB device term — should we add an OBI import following the pattern used in DrOn and OMRSE, or would you prefer a different approach for now?

[hoganwr]

I'm still pondering whether to include the "device" class and if so how. I don't think we'll end up using much of OBI, so it might not make sense to get the device class from there. For now, let's put "medical device" under "material entity".

[hoganwr]

Some language from the FDA statutes for help in defining 'medical device', although we are absolutely trying to define it generally for use worldwide, NOT specific to U.S.

...intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment, or prevention of disease, in man or other animals, or
(C) intended to affect the structure or any function of the body of man or other animals, and which does not achieve its primary intended purposes through chemical action within or on the body of man or other animals and which is not dependent upon being metabolized for the achievement of its primary intended purposes. The term "device" does not include software functions excluded pursuant to section 520(o).

[hoganwr]

'medical device' =def A material entity manufactured with a function either (1) to diagnose, cure, mitigate, treat, or prevent disease or (2) to alter physically (i.e., not chemically) the structure or functioning of some part of the body of an organism.

[hoganwr]

Note: it should be object and not material entity, because when the FDA approves certain reagents as medical devices, it is approving container+solution, which is an object per BFO.

So:

'medical device' =def An object manufactured with a function either (1) to diagnose, cure, mitigate, treat, or prevent disease or (2) to alter physically (i.e., not chemically) the structure or functioning of some part of the body of an organism.

Parent: BFO:object

Comment: It is an object and not a material entity, because when the FDA approves certain reagents as medical devices, it is approving container+solution, which is an object per BFO. Note that such reagents are for use, for example, in the laboratory, and are not ingested (those would be drug products per the FDA).

Comment: We are defining this term as generically as possible. So although informed by FDA regulations, we intend this definition to be more general and apply to any country.

[hoganwr]

'activity of daily living assistive device' =def A medical device whose function is to improve the degree (or quality) of realization of an organism's capability to perform one or more activities of daily living.

Comment: Examples of activities of daily living include locomotion (e.g., walking), eating, grooming, toileting, housekeeping, bathing, meal preparation, and shopping.

[hoganwr]

'locomotion assistive device' =def An activity of daily living assistive device whose function is to improve the degree of realization of an organism's capability for locomotion.

'assistive device for donning or removing clothing' =def An activity of daily living assistive device whose function is to improve the degree of realization of an organism's capability to don or remove one or more articles of clothing.

Synonym: 'dressing assistive device'
Related term: 'dressing aid'

'grasping or holding assistive device' =def An object manufactured with the function to enhance an organism's capability to grasp or hold onto other objects.

Comment: It is not the case that every grasping or holding device is a medical device, so we put them under object. For example, you can buy a reacher at a big box store that is not registered with the FDA.

[hoganwr]

Note: GO defines 'locomotion' as "Self-propelled movement of a cell or organism from one location to another."

That prevents cars, planes, and trains from being captured by our definition of 'locomotion assistive device'. Fortunately, we are not being asked for electric wheelchairs yet, but when and if we are, we will need to think about personal mobility aids and the likelihood that an electric wheelchair (a personal mobility aid) is not a locomotion assistive device (and thus not a wheelchair, which could be a challenge for the more linguistically minded, but we can assign 'electric wheelchair' as an alternative term to help avoid the worst of their cognitive dissonance).

[hoganwr]

Once we merge PR #68 we next need to add the specific device terms, beginning with locomotion assistance devices as follows:

wheelchair
wheeled walker
rollator
hemi-walker
single point cane
quad cane
sliding board

Some proposals:
'wheelchair' =def "A locomotion assistive device that (1) supports the body in a seated position, (2) has two or more wheels as part, and (3) whose locomotion function, if realized, is realized by a process that has as part rotating of its wheels."

[manojniwas]

Following the wheelchair definition pattern and grounding definitions in FDA CFR 21 Part 890, here are proposed definitions for the remaining locomotion assistive devices:
wheeled walker =def A locomotion assistive device that (1) supports the body in an upright standing position, (2) has a frame with four legs as part, (3) has two or more wheels as part, and (4) whose locomotion function, if realized, is realized by a process that has as part rolling of its wheels while the organism walks.

Note: FDA CFR 21 §890.3825 defines a mechanical walker as "a four-legged device with a metal frame intended for medical purposes to provide moderate weight support while walking." https://www.law.cornell.edu/cfr/text/21/890.3825
rollator =def A wheeled walker that (1) has hand-operated brakes as part, and (2) has a seat as part.

Synonym: wheeled walker
hemi-walker =def A locomotion assistive device that (1) supports the body in an upright standing position, (2) has four legs as part, and (3) is designed to be operated with a single upper limb.
single point cane =def A locomotion assistive device that (1) supports the body in an upright standing position, (2) has a single point of contact with the ground as part, and (3) whose locomotion function, if realized, is realized by a process that has as part the organism bearing weight through a handle.

Note: FDA CFR 21 §890.3075 defines a cane as "a device intended for medical purposes that is used to provide minimal weight support while walking. Examples include a standard cane, a forearm cane, and a cane with a tripod, quad, or retractable stud on the ground end." https://www.law.cornell.edu/cfr/text/21/890.3075
quad cane =def A locomotion assistive device that (1) supports the body in an upright standing position, (2) has four points of contact with the ground as part, and (3) whose locomotion function, if realized, is realized by a process that has as part the organism bearing weight through a handle.

Synonym: four-point cane

Note: Same FDA reference as single point cane — 21 CFR §890.3075. https://www.law.cornell.edu/cfr/text/21/890.3075
sliding board =def A locomotion assistive device that (1) supports the body in a seated position, (2) is a rigid flat surface, and (3) whose locomotion function, if realized, is realized by a process that has as part sliding of the organism from one seated surface to another.

Synonym: transfer board

Note: FDA CFR 21 §890.5050 classifies sliding board as a "daily activity assist device" — "a modified adaptor or utensil (e.g., a transfer aid) that is intended for medical purposes to assist a patient to perform a specific function." https://www.ecfr.gov/current/title-21/chapter-I/subchapter-H/part-890/subpart-F/section-890.5050

FDA 510(k) K772417 classifies sliding board under "Aid, Transfer": https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm?ID=K772417

[hoganwr]

It looks like the text "synonym: wheeled walker" is stray text that should not be there. Obviously the rdfs:label of the wheeled walker class will be 'wheeled walker'. Did you mean to have some other synonym for wheeled walker?

One of the important distinctions between rolling supports and non-rolling ones is that the rolling ones never lose contact with flat surfaces and thus are continuously supporting the weight of the body during locomotion, whereas canes are lifted off the surface (floor, ground), moved forward, and placed down again and thus do not continuously support the weight of the body during locomotion.

wheeled walker =def A locomotion assistive device that (1) supports the body in an upright standing position, (2) has a frame with four legs as part, (3) has two or more wheels as part, and (4) whose locomotion function, if realized, is realized by a process that (a) has as part rolling of its wheels while the organism walks and (b) has continuous (i.e., uninterrupted) support of the organisms weight.

hemi-walker =def A locomotion assistive device that (1) supports the body in an upright standing position, (2) has four legs as part, (3) is designed to be operated with a single upper limb, and (4) whose locomotion function, if realized, is realized by a process that has alternating parts of (a) weight support and (b) non-weight support when the device is either slid forward or lifted in the air to move it forward before the next weight supporting part.

single point cane =def A locomotion assistive device that (1) supports the body in an upright standing position, (2) has a single point of contact with the ground as part, (3) has as part a handle where the organism grasps it during locomotion, and (4) whose locomotion function, if realized, is realized by a process that has alternating parts of (a) weight support and (b) non-weight support when the device is lifted in the air to move it forward before the next weight supporting part.

quad cane =def A locomotion assistive device that (1) supports the body in an upright standing position, (2) has four points of contact with the ground as part, (3) has as part a handle where the organism grasps it during locomotion, and (4) whose locomotion function, if realized, is realized by a process that has alternating parts of (a) weight support and (b) non-weight support when the device is lifted in the air to move it forward before the next weight supporting part.
Synonym: four-point cane

sliding board =def A locomotion assistive device that (1) supports the body in a seated position, (2) is a rigid flat surface, and (3) whose locomotion function, if realized, is realized by a process that has as part sliding of the organism from one seated surface to another.
Synonym: transfer board
Comment: The seated surfacees from and to which the organism is moved are typically beds, chairs, and other locomotion assistive devices such as wheelchairs.

[hoganwr]

I'd like to suggest we work on these terms, which would all be children of "dressing assistive device", next:

Sock aid
Dressing Stick
Shoe Horn
Long Handled Shoe Horn

And in addition to those, "reacher", which would be a child of "grasping or holding assistive device"

[manojniwas]

Sock aid
=def A dressing assistive device that (1) has a curved or trough-shaped body designed to hold a sock or stocking open, (2) has one or more straps or cords attached to the body as part, and (3) whose donning function, if realized, is realized by a process that has as part the organism's foot sliding into the sock while it is held open by the device's body.
Editor note: FDA 21 CFR §890.5050 classifies dressing aids generally as a "daily activity assist device" (Class I, general controls, exempt from premarket notification). Source: https://www.law.cornell.edu/cfr/text/21/890.5050
Dressing stick
=def A dressing assistive device that (1) is a rigid elongated shaft, and (2) has one or more hooks as part at one or both ends, and (3) whose donning or removing function, if realized, is realized by a process that has as part a hook engaging an article of clothing to pull it onto, or push or pull it off of, part of the organism's body.
Editor note: same §890.5050 reference. Source: https://www.law.cornell.edu/cfr/text/21/890.5050
Shoe horn
=def A dressing assistive device that (1) has a curved, rigid blade-shaped body, and (2) whose donning function, if realized, is realized by a process that has as part the organism's heel sliding along the device's curved surface into the back of a shoe.
Editor note: same §890.5050 reference. Source: https://www.law.cornell.edu/cfr/text/21/890.5050
Long handled shoe horn
=def A shoe horn that has an elongated handle as part, sufficient to enable donning a shoe without the organism bending at the waist.
Open question : I have drafted this as a subclass of Shoe Horn (parallel to how quad cane relates to cane), differentiated only by handle length. Your original May 15 hierarchy sketch listed it as a flat sibling under dressing assistive device instead. Let me know which you'd prefer. If sibling, the definition would need to restate the full shoe-horn structure rather than inherit it.
Reacher
=def A grasping or holding assistive device that (1) is an elongated rigid or semi-rigid shaft, (2) has a jaw or claw mechanism as part at the distal end, (3) has a trigger or lever as part at the proximal (handle) end that operates the jaw, and (4) whose grasping or holding function, if realized, is realized by a process that has as part closing of the jaw around an object at a distance from the organism's body.
Open question : I didn't find an FDA CFR classification specific to reachers, which is consistent with "grasping or holding assistive device" being deliberately parented under object rather than medical device (not every reacher is FDA-registered). Also  your original May 15 hierarchy used "medical reacher device" as the label, but your latest ask just says "reacher." Should the label stay "reacher," or did you intend "medical reacher device"?

[hoganwr]

1. Agree w/long handled shoe horn as subclass of shoe horn
2. Let's go with "reacher device" as the label (not going with medical)