(a) Upon the trial of any civil case involving injury, disease, or disability, the patient, a member of his family, or any other person responsible for the care of the patient shall be a competent witness to identify doctor bills, hospital bills, ambulance service bills, drug bills, and similar bills for expenses incurred in the treatment of the patient upon a showing by the witness that such bills were received from a licensed practicing physician, hospital, ambulance service, pharmacy, drug store, or supplier of therapeutic or orthopedic devices, and that such expenses were incurred in connection with the treatment of the injury, disease, or disability involved in the subject of litigation at trial.
(b) Such items of evidence need not be identified by the person who submits the bill, and it shall not be necessary for an expert witness to testify that the charges were reasonable and necessary.