Biological introduction apparatus and endoscope having biological introduction apparatus

A biological introduction apparatus which is introduced into a living body in a state that an insertion unit of an endoscope having a longitudinal axis is inserted therethrough, and has a distal end portion and a proximal end portion, comprising:

• a drive force generation and input mechanism which has an insertion hole through which the insertion unit is inserted, is arranged on the proximal end portion side, generates drive force by rotating in a periaxial direction of the longitudinal axis, and inputs the drive force;
• a drive force transmission mechanism that is distal to the drive force generation and input mechanism, arranged on an outer side of the insertion unit inserted through the insertion hole in a radial direction of the insertion unit, and arranged on part of a circumference of the biological introduction apparatus in a circumferential direction thereof, the drive force transmission mechanism having an elongated shaft member which rotates in the periaxial direction by the drive force input by the drive force generation and input mechanism to transmit the drive force;
• a helical rotation member which has a cylindrical main body portion which has flexibility, through which the insertion unit is inserted, and rotates in the periaxial direction of the longitudinal axis by the drive force transmitted by the shaft member;
• and a fin portion which is arranged on an outer peripheral surface of the main body portion and also helically arranged in the periaxial direction of the longitudinal axis, the helical rotation member being arranged on the distal end portion side and a distal end portion of the helical rotation member being arranged at the distal end of the biological introduction apparatus;
• a holding member which has an insertion hole through which a proximal end portion of the main body portion is inserted, is arranged on the proximal end portion side of the biological introduction apparatus and is further proximal on the apparatus than the fin portion in the longitudinal axis direction, and holds the proximal end portion side of the main body portion in such a manner that the proximal end portion side of the main body portion is coupled with a distal end portion of the shaft member with the proximal end portion of the main body portion being inserted through the insertion hole, the drive force is transmitted from the distal end portion of the shaft member to the proximal end portion side of the main body portion, and the main body portion rotates in the periaxial direction of the longitudinal axis by the drive force;
• and
• a positioning mechanism which positions the proximal end portion of the main body portion to an intermediate portion arranged between the distal end portion of the insertion unit and the proximal end portion of the insertion unit in such a manner that the helical rotation member is attached to the insertion unit.