Abstract: An apparatus for optically observing a body cavity in which the view field is made more clear by eliminating mucus in the body cavity. The apparatus includes a tubular fluid passage forming member which surrounds an insert part and which is inserted into the body cavity. A space between the fluid passage forming member and the outer face of the insert part is divided into a fluid supply space and discharge space. The fluid supply space is externally supplied with fluid such as clean water and the mucus in the body cavity is discharged to the outside of the body via the fluid discharge space. The fluid passage forming member is made of economical material such as plastics so that it may be disposable, reducing the risk of infecting a patient with a virus.

Abstract: An adjustable position fixing apparatus for fixing instruments such as an endoscope and an illuminator in a desired spatial position is provided. The adjustable position fixing apparatus for an instrument and the like comprises a cylinder communicating with a pressure fluid supplying machine, such as a compressor, through a switching device, a mount member for mounting an instrument and the like thereon, and an adjustable bending arm portion through which a linear element such as a wire extends. The arm portion is disposed between the cylinder and the mount member over an entire area or a part thereof. One end of the linear element is attached to a reciprocating rod of the cylinder and the other end is attached to the mount member.