Does the installation and purchase price a deduction because I need 24 hour oxygen? It is powered by natural gas.

This could be a medical expense--the medical expense deduction is a tough one to get, however.  Only the amount that is over 10% of your AGI is deductible, and the other "catch" is that you cannot use itemized deductions unless they exceed your standard deduction, which is very hard for many people now.

https://turbotax.intuit.com/tax-tips/health-care/medical-expenses-checklist/L6MkxxlyW

MEDICAL EXPENSES

The medical expense deduction has to meet a rather large threshold before it can affect your return. The amount of medical (including dental, vision, etc.)  expenses that will count toward itemization is the amount that is OVER 10% of your adjusted gross income. You should only enter the amount that you paid in 2019—do not include any amounts that were covered by insurance or that are still outstanding. Of course, your medical expenses plus your other itemized deductions still have to exceed your standard deduction before you will see a difference in your tax due or refund.

To enter your medical expenses go to Federal>Deductions and Credits>Medical>Medical Expenses

2019 Standard Deduction Amounts

Single $12,200   (+ $1650 65 or older)

Married Filing Separate  $12,200   (+ $1300 if 65 or older)

Married Filing Jointly $24,400   (+ $1300 for each spouse 65 or older)

Head of Household $18,350  (+ $1650 for 65 or older)

(Also + $1650 if legally blind)