Non-PRO Chinese to English Law/Patents Medical (general) PRC Medical Law

literally I think this could be:

"Persons with a relationship to the patient" or
"related persons"

but both of these seem far too vague for the seriousness of the situation(granting consent for surgery, for context see below).

Is there a special legal meaning for this term in Chinese. What kind of a person is a 关系人，and is there a specific legal scope of the sorts of relationships that this covers? 原文 and 译文 are below.

医疗机构施行手术、特殊检查或者特殊治疗时，必须征得患者同意，并应当取得其家属或者关系人同意并签字；无法取得患者意见时，应当取得家属或者关系人同意并签字；无法取得患者意见又无家属或者关系人在场，或者遇到其他特殊情况时，经治医师应当提出医疗处置方案，在取得医疗机构负责人或者被授权负责人员的批准后实施。

When any surgery, special examination, or special treatment is performed, the signed consent of the patient and the signed consent of the patient’s family members or other persons with a relationship to the patient must be obtained. When a patient’s opinion is unobtainable, family members or other persons with a relationship to the patient shall give consent and sign the consent form. If a patient’s opinion is unobtainable and patient’s family members or persons with a relationship to the patient are not present, or in the case of other special circumstances, the attending physician shall propose a treatment plan and implement it after obtaining the approval of the head administrator of the health care organization or other authorized responsible person.