Subject to Section 4753, a petition may be filed under this part by any of the following persons:
(a) The patient.
(b) The patient’s spouse, unless legally separated.
(c) A relative of the patient.
(d) The patient’s agent or surrogate.
(e) The conservator of the person of the patient.
(f) The court investigator, described in Section 1454, of the county where the patient resides.
(g) The public guardian of the county where the patient resides.
(h) The supervising health care provider or health care institution involved with the patient’s care.
(i) Any other interested person or friend of the patient.