Patent Application
20080009848
As depicted in
Blade body 112 includes a proximal plate shaped portion 122, an elongate longitudinal portion 124, and a hook-shaped distal end portion 126 all integrally continuously formed with each other. Blade body 112 is eccentrically disposed relative to a longitudinal axis 128 of blade 110 and particularly of shank 114. Elongate blade portion 124 is slightly tapered and oriented substantially parallel to axis 128. An outer elongate cutting edge section 130 of elongate blade portion 124 is slightly inclined relative to axis 128 and is continuous at a distal end with a circularly arcuate cutting edge 132 defining a distal periphery of hook-shaped distal end portion 126.
Blade body 112 is eccentrically disposed relative to axis 128 in that elongate or longitudinal blade portion 124 is disposed entirely to one side of the axis. During use of blade 110, this eccentricity is believed to convert a portion of the energy of longitudinal ultrasonic compression waves into ultrasonic transverse waves, whereby elongate or longitudinal blade portion 124 exhibits a motion component oriented substantially transversely to axis 128 and cutting edge 130. It is believed that this transverse motion enhances a lateral cutting action of edge 130, in a direction generally transversely to axis 128. Where an ultrasonic cutting blade is symmetrically formed as disclosed in U.S. Pat. Nos. 6,379,371 and 6,443,969, the cutting action is generally limited to a forward or distal side of the blade (cutting edge 132 in
Plate shaped blade portion 122, elongate longitudinal blade portion 124, and hook-shaped distal end portion 126 together define a cutout or recess 134 between shank 114 at a proximal end and hook portion 126 at the distal end of blade body 112. Cutout or recess 134 is substantially but not perfectly rectangular, owing to the tapered aspect of blade body 112 and more particular to distal end portion 126 having a smaller transverse dimension or width than proximal plate shaped portion 122.
A bore or channel 136 provided in shank 114 communicates at a distal end with a narrower bore or channel 138 in proximal blade portion 122. Channel 138 in turn communicates with recess 134. Channels 136 and 138 deliver irrigating and cooling liquid to recess 134 for distribution over blade body 112. To that end, a notch 140 and a liquid distribution surface 142 are provided in hook-shaped distal end portion 126 of blade body 112 for assisting in the conduction of a coolant liquid to cutting edge 132.
Distal end portion 126 of blade body 112 has a cutting edge 144 facing in a proximal direction toward from shank 114, while elongate blade portion 124 has a cutting edge 146 facing laterally toward from axis 128. Cutting edge 144 is sharp while cutting edge 146 is blunt, having the thickness of blade body 112 along the elongate longitudinal portion 124 thereof.
Shank 114 has a shank width SW1 in a direction substantially perpendicular to axis 128, while elongate portion 124 of blade body 112 has a width BW1 also measured in a direction substantially perpendicular to axis 128. Blade width BW1 is substantially less than shank width SW1, which facilitates the eccentric disposition of blade body 112 relative to shank 114. Blade body 112 has a thickness (not shown) substantially less than blade width BW1.
Arcuate cutting edge 132 of distal end portion 126 extends through an arc of 180 degrees in the embodiment of
The straight or linear cutting sections or edges 130 and 146 are longitudinal and oriented substantially parallel to the axis 128 of blade 110. Elongate portion 124 of blade body 112 is tapered, the outwardly facing cutting edge 130 extending at an angle of 5-15 degrees relative to axis 128.
Cutting edges 130 and 146 do not necessarily have to have the same sharpness. For instance, the outer longitudinal edge 130 may be sharp and the inner edge 146 may be blunt, or vice versa.
Cutting edges 130, 132, 144, 146 of blade 110 are continuous (except for notch 140), i.e., have no teeth, serrations or voids. This continuity provides a smooth contact surface essential when making precise cuts.
Blade body 212 does not include a proximal plate shaped portion like proximal plate shaped portion 122 of blade body 112. Instead, shank 214 is directly continuous with an elongate longitudinal portion 224 of blade body 212.
Blade body 212 further includes a hook-shaped distal end portion 226 integrally continuously formed with elongate blade portion 224. Blade body 212 is eccentrically disposed relative to a longitudinal axis 228 of blade 210 and particularly of shank 214, owing to a staggered lateral disposition of elongate portion 224 relative to shank 214. During use of blade 210, this eccentricity is believed to convert a portion of the energy of longitudinal ultrasonic compression waves into ultrasonic transverse waves, whereby elongate or longitudinal blade portion 224 exhibits a motion component oriented substantially transversely to axis 228 and cutting edge 230. It is believed that this transverse motion enhances a lateral cutting action of edge 230, in a direction generally transversely to axis 228.
Elongate blade portion 224 is rectangular and has a uniform width BW2. Elongate blade portion 224 is oriented substantially parallel to axis 228. An outer elongate cutting edge section 230 of elongate blade portion 224 is parallel to axis 228 and is continuous at a distal end with a circularly arcuate cutting edge 232 defining a distal periphery of hook-shaped distal end portion 226.
The distal end of shank 214, elongate longitudinal blade portion 224, and hook-shaped distal end portion 226 together define a rectangular cutout or recess 234 between shank 214 at a proximal end and hook portion 226 at the distal end of blade body 212.
A proximal bore or channel 236 in shank 214 communicates at a distal end with a narrower bore or channel 238 in a tapered distal end (not separately labeled) of shank 214. Channel 238 in turn communicates with recess 234. Channels 236 and 238 deliver irrigating and cooling liquid to recess 234 for distribution over blade body 212. To that end, a notch 240 and a liquid distribution surface 242 are provided in hook-shaped distal end portion 226 of blade body 212 for assisting in the conduction of a coolant liquid to cutting edge 232.
Distal end portion 226 of blade body 212 has a sharp cutting edge 244 and a blunt cutting edge 245 facing in a proximal direction toward from shank 214, while elongate blade portion 224 has a blunt cutting edge 246 facing laterally toward from axis 228. Cutting edges 245 and 246 are blunt and have the thickness of blade body 212.
Shank 214 has a shank width SW2 in a direction substantially perpendicular to axis 228, while elongate portion 224 of blade body 212 has width BW2 also measured in a direction substantially perpendicular to axis 228. Blade width BW2 is substantially less than shank width SW2, which facilitates the eccentric disposition of blade body 212 relative to shank 214. Blade body 212 has a thickness (not shown) substantially less than blade width BW2.
Arcuate cutting edge 232 of distal end portion 226 extends through an arc of 180 degrees in the embodiment of
The straight or linear cutting sections or edges 230, 246, and 248 are longitudinal and oriented parallel to the axis 228 of blade 210. Cutting edges 230, 232, 244, 246 of blade 210 are continuous (except for notch 240), i.e., have no teeth, serrations or voids. This continuity provides a smooth contact surface essential when making precise cuts.
As depicted in
Blade body 312 includes a proximal plate shaped portion 322, an elongate longitudinal portion 324, and a truncated hook-shaped distal end portion 326 all integrally continuously formed with each other. Blade body 312 is eccentrically disposed relative to a longitudinal axis 328 of blade 310 and particularly of shank 314. Elongate blade portion 324 is slightly tapered and oriented substantially parallel to axis 328. An outer elongate cutting edge section 330 of elongate blade portion 324 is slightly inclined relative to axis 328 and is continuous at a distal end with a circularly arcuate cutting edge 332 defining a distal periphery of hook-shaped distal end portion 326.
Blade body 312 is eccentrically disposed relative to axis 328 in that elongate or longitudinal blade portion 324 is disposed entirely to one side of the axis. During use of blade 310, this eccentricity is believed to convert a portion of the energy of longitudinal ultrasonic compression waves into ultrasonic transverse waves, whereby elongate or longitudinal blade portion 324 exhibits a motion component oriented substantially transversely to axis 328 and cutting edge 330. It is believed that this transverse motion enhances a lateral cutting action of edge 330, in a direction generally transversely to axis 328.
Plate shaped blade portion 322, elongate longitudinal blade portion 324, and hook-shaped distal end portion 326 together define a shallow rectangular cutout or recess 334 between shank 314 at a proximal end and hook portion 326 at the distal end of blade body 312.
A bore or channel 336 provided in shank 314 communicates at a distal end with a narrower bore or channel 338 in proximal blade portion 322. Channel 338 in turn communicates with recess 334. Channels 336 and 338 deliver irrigating and cooling liquid to recess 334 for distribution over blade body 312. To that end, a notch 340 and a liquid distribution surface 342 are provided in hook-shaped distal end portion 326 of blade body 312 for assisting in the conduction of a coolant liquid to cutting edge 332.
Distal end portion 326 of blade body 312 has a cutting edge 344 facing in a proximal direction toward from shank 314, while elongate blade portion 324 has a cutting edge 346 facing laterally toward from axis 328. Cutting edge 344 is sharp (owing to the formation of notch 340 and surface 334) while cutting edge 346 is blunt, having the thickness of blade body 312 along the elongate longitudinal portion 324 thereof.
Shank 314 has a shank width SW3 in a direction substantially perpendicular to axis 328, while elongate portion 324 of blade body 312 has a width BW3 also measured in a direction substantially perpendicular to axis 328. Blade width BW3 is substantially less than shank width SW3, which facilitates the eccentric disposition of blade body 312 relative to shank 314. Blade body 312 has a thickness (not shown) substantially less than blade width BW3.
Arcuate cutting edge 332 of distal end portion 326 extends through an arc of 90 degrees in the embodiment of
The straight or linear cutting sections or edges 330 and 346 are longitudinal and oriented substantially parallel to the axis 328 of blade 310. Elongate portion 324 of blade body 312 is tapered, the outwardly facing cutting edge 330 extending at an angle of 5-15 degrees relative to axis 328.
Cutting edges 330, 332, 346 of blade 310 are continuous (except for notch 340), i.e., have no teeth, serrations or voids. This continuity provides a smooth contact surface essential when making precise cuts.
As shown in
Blade body 412 does not include a proximal plate shaped portion like proximal plate shaped portion 142 of blade body 112. Instead, shank 414 is directly continuous with an elongate longitudinal portion 424 of blade body 412.
Blade body 412 further includes a truncated hook-shaped distal end portion 426 integrally continuously formed with elongate blade portion 424. Blade body 412 is eccentrically disposed relative to a longitudinal axis 428 of blade 410 and particularly of shank 414, owing to a staggered lateral disposition of elongate portion 424 relative to shank 414 and axis 428. During use of blade 410, this eccentricity is believed to convert a portion of the energy of longitudinal ultrasonic compression waves into ultrasonic transverse waves, whereby elongate or longitudinal blade portion 424 exhibits a motion component oriented substantially transversely to axis 428 and cutting edge 430. It is believed that this transverse motion enhances a lateral cutting action of edge 430, in a direction generally transversely to axis 428.
Elongate blade portion 424 is rectangular and has a uniform width BW2. Elongate blade portion 424 is oriented substantially parallel to axis 428. An outer elongate cutting edge section 430 of elongate blade portion 424 is parallel to axis 428 and is continuous at a distal end with a circularly arcuate cutting edge 432 defining a distal periphery of hook-shaped distal end portion 426.
The distal end of shank 414, elongate longitudinal blade portion 424, and hook-shaped distal end portion 426 together define a shallow or thin rectangular cutout or recess 434 between shank 414 at a proximal end and hook portion 426 at the distal end of blade body 412.
A proximal bore or channel 436 in shank 414 communicates at a distal end with a narrower bore or channel 438 in a tapered distal end (not separately labeled) of shank 414. Channel 438 in turn communicates with recess 434. Channels 436 and 438 deliver irrigating and cooling liquid to recess 434 for distribution over blade body 412. To that end, a notch 440 and a liquid distribution surface 442 are provided in hook-shaped distal end portion 426 of blade body 412 for assisting in the conduction of a coolant liquid to cutting edge 432.
Distal end portion 426 of blade body 412 has a sharp cutting edge 444 (owing to the formation of notch 440 and surface 434) facing in a proximal direction toward from shank 414, while elongate blade portion 424 has a blunt cutting edge 446 facing laterally toward from axis 428. Cutting edge 446 is blunt and has the thickness of blade body 412.
Shank 414 has a shank width SW4 in a direction substantially perpendicular to axis 428, while elongate portion 424 of blade body 412 has width BW4 also measured in a direction substantially perpendicular to axis 428. Blade width BW4 is substantially less than shank width SW4, which facilitates the eccentric disposition of blade body 412 relative to shank 414. Blade body 412 has a thickness (not shown) substantially less than blade width BW4.
Arcuate cutting edge 432 of distal end portion 426 extends through an arc of 90 degrees in the embodiment of
The straight or linear cutting sections or edges 430, 446, and 448 are longitudinal and oriented parallel to the axis 428 of blade 410. Cutting edges 430, 432, 446 of blade 410 are continuous (except for notch 440), i.e., have no teeth, serrations or voids. This continuity provides a smooth contact surface essential when making precise cuts.
Ultrasonic surgical blade 110, 210, 310, and 410 are particularly suited for performing a spinal laminectomy. Shank 114, 214, 314, 414 is connected at an end opposite blade body 112, 212, 312, 412 to a source of ultrasonic vibrations (not shown). Thereafter blade 110, 210, 310, 410 is moved into a patient, the blade being ultrasonically vibrated during this movement, so that cutting edge 132, 232, 332, 432 cuts into tissues of the patient. Subsequently the surgeon pulls the blade 110, 210, 310, 410 in a proximal direction out of the patient so that cutting edge 144, 244, 344, 444 engages bony tissue of the patient. Blade 110, 210, 310, 410 is ultrasonically vibrated during the pulling of the blade against the bony tissue to thereby enable the cutting of the bony tissue by cutting edge 144, 244, 344, 444.
The blade body 112, 212, 312, 412 is shifted laterally after the insertion or moving of the blade 110, 210, 310, 410 into the patient and prior to the pulling of the blade in a proximal direction out of the patient. The blade 110, 210, 310, 410 is nd ultrasonically vibrated during the lateral shifting of the blade to thereby enable cutting edge 146, 246, 346, 446 to cut through tissues of the patient as required. Owing to the eccentric disposition of elongate blade portion 124, 224, 324, 424, for instance, entirely to one side of the shank axis 128, 228, 328, 428, a transmission of a longitudinal ultrasonic compression wave into the blade 110, 210, 310, 410 via shank 114, 214, 314, 414 during the shifting of the blade gives rise to a transverse ultrasonic shear wave that vibrates elongate blade portion 124, 224, 324, 424 in a direction orthogonal to the axis. Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.
