Section 52. In sections fifty-one to fifty-six, inclusive, the following words shall have the following meanings:—

''Certified clinical specialist in psychiatric and mental health nursing'', a registered nurse licensed under the provisions of section eighty B of chapter one hundred and twelve and authorized by the board of registration in nursing to practice as a certified clinical specialist in psychiatric and mental health nursing.

''Hospital'', any institution, however named, whether conducted for charity or for profit, which is advertised, announced, established or maintained for the purpose of caring for persons admitted thereto for diagnosis, medical, surgical or restorative treatment which is rendered within said institution.

''Institution for unwed mothers'', any institution or place, however named whether conducted for charity or profit which is advertised, announced, established or maintained for the purpose of caring for one or more unwed mothers admitted thereto, on a resident basis, for prenatal care, supervision and short-term postnatal care.

''Limited services'', diagnosis, treatment, management and monitoring of acute and chronic disease, wellness and preventative services of a nature that may be provided within the scope of practice of a nurse practitioner using available facilities and equipment, including shared toilet facilities for point-of-care testing.

''Limited services clinic'', a clinic that provides limited services as defined by section 51J.

''Clinic'', any entity, however organized, whether conducted for profit or not for profit, which is advertised, announced, established, or maintained for the purpose of providing ambulatory medical, surgical, dental, physical rehabilitation, or mental health services. In addition, ''clinic'' shall include any entity, however organized, whether conducted for profit or not for profit, which is advertised, announced, established, or maintained under a name which includes the word ''clinic'', ''dispensary'', or ''institute'', and which suggests that ambulatory medical, surgical, dental, physical rehabilitation, or mental health services are rendered therein. With respect to any entity which is not advertised, announced, established, or maintained under one of the names in the preceding sentence, ''clinic'' shall not include a medical office building, or one or more practitioners engaged in a solo or group practice, whether conducted for profit or not for profit, and however organized, so long as such practice is wholly owned and controlled by one or more of the practitioners so associated, or, in the case of a not for profit organization, its only members are one or more of the practitioners so associated or a clinic established solely to provide service to employees or students of such corporation or institution. For purposes of this section, clinic shall not include a clinic conducted by a hospital licensed under section fifty-one or by the federal government or the commonwealth.

''Original license'', a license issued to a hospital, institution for unwed mothers or clinic, not previously licensed; or a license issued to an existing hospital, institution for unwed mothers or clinic, in which there has been a change in ownership or location.

''Out-of-hospital dialysis unit'', a unit, however named, maintained separately from a hospital or a license issued thereto, whether conducted for charity or for profit, for the purpose of providing dialysis treatment to persons suffering from renal disease. It shall not include a dialysis unit maintained as part of a hospital.

''Practitioner'', any individual who may diagnose and treat medical, surgical, dental, physical rehabilitation, or mental health problems without limitation within the confines of his profession.

''Rural hospital'', an acute-care hospital as defined in section 25B and licensed under this chapter, which: (1) has been designated by the department as a rural hospital based on bed size, city or town population, and population density of the city, town, service area or county as determined by the department through regulation; or (2) a hospital currently designated as a critical access hospital by the United States Department of Health and Human Services in accordance with federal regulations and state requirements.