| 摘要 |
An ultrasonic surgical drill or drill bit includes a tubular member having a longitudinal axis of symmetry and a plurality of fins extending in longitudinal planes each containing the axis. In a surgical method utilizing the drill bit, one places a distal tip of the drill bit in contact with bone, presses the drill bit against the bone, and during that pressing of the drill bit, conducts ultrasonic vibrations into the drill bit. With the fins in contact with the bone, the drill bit is oscillated or angularly reciprocated about a longitudinal axis, so that the fins fragment bone material located between the fins. |
| 主权项 |
1. A medical instrument comprising:
a tubular member having a longitudinal axis of symmetry; and a plurality of fins connected to said tubular member and extending in longitudinal planes each containing said axis, each of said fins having a distal end portion and a proximal end portion, said distal end portion being spaced from a distal tip of said tubular member, said distal end portion having a width, in the respective longitudinal plane and measured in a radial direction relative to said axis, that increases with increasing distance from said distal tip, said distal end portion having a maximum width at a proximal end, said proximal end portion having a width, in the respective longitudinal plane and measured in a radial direction relative to said axis, that decreases with increasing distance from said distal tip, said proximal end portion having a maximum width at a distal end, the maximum width of said distal end portion and the maximum width of said proximal end portion being equal. |
