It is customary to teach the patient and/or a family member the skills required to
            administer insulin injections safely and effectively. Once the patient or other nonmedical
            person has mastered these skills, they are to all intents and purposes functioning
            as a  skilled person when administering or self-administering the injection. If a patient is unable
            to learn these skills or is physically or mentally incapable of performing the service
            for themselves, e.g., they are blind, senile, or spastic, and there is no one else
            willing and able to learn and perform the service for them, the administration of
            the injection by a nurse constitutes a skilled nursing service.