Thanks for your question. I’m not certain which type of categorization you’re referring to, but in terms of Facebook Advertising industries your business would fall under Retail (average cost per click of $0.70) and Healthcare (average cost per click of $1.32).
If you’re looking to run Facebook ads, you will want to be sure really hone in on your audience targeting since you have a very specific demographic of potential customers. Here’s an article that gives more details on how to go about targeting specific Facebook audiences (or people) who your ad will show to. One audience targeting strategy that comes to mind for your business is targeting Facebook Groups. There are so many Facebook Groups for all sorts of things, including groups for those with mobility issues. Another way would be by looking through the profiles of those who like your competitors and seeing if there are common “Interests” among them. If so, target audiences using that Interest.
As far as the cost structure, cost per click is likely your best bet since you only pay when people who see your ad actually click on it. This means you only pay when your ad effectively lands in front of people who are actually interested, opposed to say cost per view, that may get your ad seen, but not necessarily interacted with.
Another thing to mention before diving into Facebook ads is the importance of having a good landing page or business page that it directs to. I’ve linked a few articles below that might be of interest and help you market your business.
Anyways, hope this helps and thanks again for your question!