An ultrasound transducer includes: a drive unit including a piezoelectric device; a proximal end block; and a distal end block. The distal end block includes a first portion, a supported portion, a second portion, and a third portion. The distal end block is configured such that a position of a boundary between the second portion and the third portion corresponds to or substantially corresponds to an antinode of the ultrasonic vibration while the piezoelectric device generates the ultrasonic vibration, and the ultrasonic vibration is being propagated to the proximal end block, the first portion, the second portion, and the third portion. A resonance frequency of the ultrasonic vibration differs according to a position of the boundary between the second portion and the third portion under a condition that a distance from the supported portion to a distal end of the third portion along the longitudinal axis is constant.

A vibration transmitter can include a straight portion, a curved portion, a first curved surface provided on an external surface of the curved portion, a second curved surface facing a side opposite to the first curved surface and a first portion provided on the first curved surface. The first portion can extend towards a side opposite to the side toward which the curved portion is curved and a distance between the first portion and an imaginary curved surface can increase from the proximal side toward the distal side, and the imaginary curved surface being parallel with the second curved surface.

An ultrasonic surgical instrument for boring a hole in a femur, including: an ultrasonic vibrator capable of generating ultrasonic vibration; a probe including a proximal end portion connected with the ultrasonic vibrator and a distal end treatment portion capable of boring a bone hole in the femur, and transmitting the ultrasonic vibration; and a cylindrical member covering the proximal end portion of the probe and not covering an exposed portion including the distal end treatment portion. The distal end treatment portion includes a columnar portion having a cross-sectional area that is larger than that of a remainder of the exposed portion of the probe.

A vibration transmitter includes: a proximal end extending portion; a supported portion; a distal end extending portion; a first relay unit provided between the supported portion and the proximal end extending portion; and a second relay unit provided between the supported portion and the distal end extending portion. The second relay unit includes a horn that is constructed such that an outer diameter at a position continuously adjacent to the supported portion is larger than: (i) an outer diameter of the first relay unit at a position continuously adjacent to the supported portion, and (ii) the outer diameter of the distal end extending portion. The horn expands amplitude of vibration output from a distal end of the distal end extending portion to be larger than a maximum amplitude at an antinode of vibration in the first relay unit or the proximal end extending portion.

An ultrasound transducer includes: a drive unit including a piezoelectric device; a proximal end block; and a distal end block. The distal end block includes a first portion, a supported portion, a second portion, and a third portion. The distal end block is configured such that a position of a boundary between the second portion and the third portion corresponds to or substantially corresponds to an antinode of the ultrasonic vibration while the piezoelectric device generates the ultrasonic vibration, and the ultrasonic vibration is being propagated to the proximal end block, the first portion, the second portion, and the third portion. A resonance frequency of the ultrasonic vibration differs according to a position of the boundary between the second portion and the third portion under a condition that a distance from the supported portion to a distal end of the third portion along the longitudinal axis is constant.

A surgical handpiece includes a torsional transducer and a surgical attachment having a first end detachably connected to the torsional transducer and a second end defining a working plane for engagement with biological tissue. The torsional transducer is configured to create a standing wave. The standing wave creates a torsional motion of the second end of the surgical attachment at the working plane.

A medical device includes: the vibration transmission member; a first cross-sectional area reduction portion, which makes a cross-sectional area of a distal end portion concerning a plane intersecting with a central axis of the vibration transmission member smaller than a cross-sectional area of the intermediate portion; and a second cross-sectional area reduction portion which makes a cross-sectional area concerning a plane intersecting with the central axis of a half portion of the vibration transmission member located opposite to the first cross-sectional area reduction portion smaller than a cross-sectional area of a half portion of the vibration transmission member located closer to the first cross-sectional area reduction portion.

HIFU (High-Intensity Focused Ultrasound) sometimes FUS or MIFUS is a highly precise medical procedure using high-intensity focused ultrasound to heat and destroy pathogenic tissue rapidly in the brain for neurosurgical purposes, by causing coagulation necrosis. Here we have described a system that uses specially designed micro-transducer heads that are placed inside the later ventricles for the purposes of MIFUS lesioning of brain targets under real time MRI, endoscopic and Doppler guidance. A minimally invasive approach using Kocher's point allows small incisions with little bleeding, recovery time, infection risk and surgical time. This approach allows insertion of the micro-ultrasound transducers into the lateral ventricles of the brain avoiding skull bone attenuation of the ultrasonic waves and unnecessary heating of brain tissues in the process.

A medical device according to one embodiment of the present invention includes: a vibration transmission member that comprises a node position of vibration and an area including the node position and a portion at a distal end side relative to the node position, and to which the vibration is transmitted; a first coating that covers a side of the node position of the area; and a second coating that covers a distal end side relative to the first coating of the area and has a thickness smaller than that of the first coating.

A surgical handpiece includes a motor that has a torsional transducer assembly along a central axis of the surgical handpiece. The motor is configured for operative connection to a power source. The torsional transducer assembly includes a plurality of torsional transducers. Each torsional transducer has a support band surrounding the torsional transducer. The surgical handpiece includes a surgical attachment that has a first end detachably connected to the motor and a second end defining a working plane for engagement with biological tissue.