An aspirator configured to move air from a proximal end of the aspirator to a distal end of the aspirator, the aspirator comprising: an aspirator body defining: an annular cavity ; a central channel ; and an annular slit ; wherein fluid communication between the annular cavity and the central channel is via the annular slit , and wherein the aspirator body defines an entrainment opening , and wherein the annular slit circumscribes and is substantially disposed about the entrainment opening , and wherein the annular cavity circumscribes and is substantially disposed about the annular slit , wherein the aspirator body immediately downstream of the annular slit diverges radially outward, and wherein the aspirator body comprises an entrainment section having a radially inward surface that faces and defines the entrainment opening , and wherein a radially outward surface of the entrainment section faces and at least partially defines the annular slit , and wherein: the aspirator body comprises an outer cavity housing ; the outer cavity housing transitions to the entrainment section such that a radially inward surface of the outer cavity housing transitions to the radially outward surface of the entrainment section and a radially outward surface of the outer cavity housing transitions to the radially inward surface of the entrainment section ; and the radially inward surface of the outer cavity housing faces and at least partially defines the annular cavity . an aspirator body defining: an annular cavity ; a central channel ; and an annular slit ; an annular cavity ; a central channel ; and an annular slit ; wherein fluid communication between the annular cavity and the central channel is via the annular slit , and wherein the aspirator body defines an entrainment opening , and wherein the annular slit circumscribes and is substantially disposed about the entrainment opening , and wherein the annular cavity circumscribes and is substantially disposed about the annular slit , wherein the aspirator body immediately downstream of the annular slit diverges radially outward, and wherein the aspirator body comprises an entrainment section having a radially inward surface that faces and defines the entrainment opening , and wherein a radially outward surface of the entrainment section faces and at least partially defines the annular slit , and wherein: the aspirator body comprises an outer cavity housing ; the outer cavity housing transitions to the entrainment section such that a radially inward surface of the outer cavity housing transitions to the radially outward surface of the entrainment section and a radially outward surface of the outer cavity housing transitions to the radially inward surface of the entrainment section ; and the radially inward surface of the outer cavity housing faces and at least partially defines the annular cavity . the aspirator body comprises an outer cavity housing ; the outer cavity housing transitions to the entrainment section such that a radially inward surface of the outer cavity housing transitions to the radially outward surface of the entrainment section and a radially outward surface of the outer cavity housing transitions to the radially inward surface of the entrainment section ; and the radially inward surface of the outer cavity housing faces and at least partially defines the annular cavity . <EOS>