Typically speaking, Medicare will not pay for bed rails or halo safety rails. If you are enrolled in the medicaid waiver program, however, you may be able to get these instruments paid for through that program.
With that being said, I suggest two things, if you have not tried them already.
Call Medicaid and explain your situation. Their number is ***** Payment for these items is fluid and sometimes a running is in the pipe that will allow them to cover these devices - especially for a person in your situation that really needs this type of assistance.
The other method here is to call medical equipment supply entities in your area. They typically are in the loop as to what can be reimbursed through medicare and medicaid as well. Moreover, they will at times have slightly used equipment at tremendous discounts that they can provide. Howard Medical in your area is good. They sell new equipment and sometimes have access to used equipment too. Here is their site: http://www.howardmedical.com/index.html
They may be able to assist you with finding a payment option, including a way to get medicare reimbursement.
However, typically speaking, Medicare will not cover items like the halo safety ring, unfortunately.
Please rate my answer positively and let me know if you have any other questions.