The respondent is entitled to secure an independent examination by a physician, clinical psychologist, clinical social worker, or other expert of his choice. If the respondent is unable to obtain an examination, he may request that the court order an examination to be made by an impartial medical expert pursuant to Supreme Court Rules or by a clinical psychologist, clinical social worker, or other expert. Determination of the compensation of the physician, clinical psychologist, clinical social worker, or other expert and its payment shall be governed by Supreme Court Rule.