Patent ID: 9352173
Filing Date: 2016-05-31
CPC Classification: A61B

Claim Text:
1. A treatment device comprising: a treatment portion which has a first distal end portion and a first proximal end portion and which transmits ultrasonic vibration generated in an ultrasonic vibrator from the first proximal end portion to the first distal end portion in a longitudinal direction, a length of the treatment portion from the first distal end portion in the longitudinal direction being portion being used for grasping a living tissue; a transmission portion having a second distal end portion, the second distal end portion being located at a node position where the node position is a position where a first generated node from the first distal end portion of the treatment portion appears, a second length of the transmission portion in the longitudinal direction being ¼ of a wavelength of the ultrasonic vibration, and, the transmission portion comprising a piezoelectric element as the ultrasonic vibrator; and a moment shift portion located between the treatment portion and the transmission portion, a length of the moment shift portion in the longitudinal direction being a third length, the moment shift portion causing an average value of I1/A12 of the treatment portion to be greater than an average value the I2/A22 transmission portion, where I1 is a second moment of area in the treatment portion calculated with respect to an axis perpendicular to a direction to which a load is applied by grasping the living tissue in a section perpendicular to the longitudinal direction, A1 is a sectional area in the treatment portion, I2 is a second moment of area in the transmission portion, and A2 is a sectional area in the transmission portion, wherein a total length of the first length in the treatment portion and the third length in the moment shift portion is ¼ of the wavelength of the ultrasonic vibration, and the treatment portion and the moment shift portion each have a U-shaped section perpendicular to the longitudinal direction.