| 主权项 |
1. An ultrasonic probe which has a longitudinal axis and which is configured to transmit an ultrasonic vibration from a proximal direction toward a distal direction, the ultrasonic probe comprising:
a transmission unit including a unit outer surface exposed to an outside, and a groove portion depressed from the unit outer surface toward a first perpendicular direction to be open toward a second perpendicular direction when two directions which are perpendicular to the longitudinal axis and which are opposite to each other are the first perpendicular direction and the second perpendicular direction, the groove portion extending over an entire length of the transmission unit in axially parallel directions parallel to the longitudinal axis, the transmission unit being point-asymmetrical with respect to the longitudinal axis; a first unit component provided in the transmission unit, the sectional shape of the first unit component perpendicular to the longitudinal axis being a first sectional shape, the first unit component having a first arc-shaped surface located a first diametrical direction dimension apart from the longitudinal axis in the first sectional shape, the first arc-shaped surface being formed on the unit outer surface; a second unit component provided to the distal direction side with respect to the first unit component in the transmission unit, the sectional shape of the second unit component perpendicular to the longitudinal axis being a second sectional shape smaller in sectional area than the first sectional shape, the second unit component having a second arc-shaped surface located a second diametrical direction dimension smaller than the first diametrical direction dimension apart from the longitudinal axis in the second sectional shape, the second arc-shaped surface being formed on the unit outer surface; and a sectional area changing portion continuous between the first unit component and the second unit component, the sectional area changing portion being located between a first antinode position which is one of antinode positions of the ultrasonic vibration and a second antinode position which is located to the distal direction side with respect to the first antinode position and which is one of the antinode positions of the ultrasonic vibration in the axially parallel directions, the sectional area changing portion changing a sectional shape perpendicular to the longitudinal axis from the first sectional shape to the second sectional shape so that a gravity center position in the case where the longitudinal axis is a reference position is consistent over the entire length of the transmission unit in the axially parallel directions, the sectional area changing portion changing the sectional area of the transmission unit perpendicular to the longitudinal axis between the first unit component and the second unit component. |
