As used in this article, the term:

(1) "Applicant" means a person who has applied for assistance under this article.

(2) "Assistance" means money payments to, or hospital care in behalf of, needy individuals who are totally and permanently disabled but does not include any such payments to or care in behalf of any such individual who is an inmate of a public institution (except as a patient in a medical institution) or any individual:

(A) Who is a patient in an institution for tuberculosis or mental illness or mental retardation; or

(B) Who has been diagnosed as having tuberculosis or being mentally ill or mentally retarded and is a patient in a medical institution as a result thereof.

(3) "Recipient" means a person who has received assistance.

(4) "Totally and permanently disabled" means any person not less than 18 nor more than 65 years of age who has a medically demonstrable disability which is permanent and which renders him incapable of performing any gainful occupation within his competence.