Surgical blade abstract
An ultrasonic surgical blade includes an ultrasonic-surgical-blade
body having a longitudinal axis, a distal tip, a proximal end adapted
for longitudinal ultrasonic vibrational excitation, a most-distal
longitudinal vibration node, a treatment portion extending from
the distal tip toward the most-distal longitudinal vibration node,
and a functional asymmetry. The functional asymmetry is asymmetric
about the longitudinal axis and translates longitudinal ultrasonic
vibrational movement of the proximal end into a combination of a
longitudinal ultrasonic vibration and a transverse ultrasonic vibration
in at least some of the treatment portion of the ultrasonic-surgical-blade
body. An amplitude of the transverse ultrasonic vibration at the
distal tip is less than substantially ten percent of a maximum amplitude
of the transverse ultrasonic vibration of the treatment portion
of the ultrasonic-surgical-blade body. An alternate embodiment of
the ultrasonic surgical blade includes at least one functional asymmetry
and at least one balance asymmetry.
Surgical blade claims
What is claimed is:
1. An ultrasonic surgical blade comprising an ultrasonic-surgical-blade
body having a longitudinal axis, a distal tip, a proximal end adapted
for longitudinal ultrasonic vibrational excitation, a most-distal
longitudinal vibration node, a treatment portion extending from
the distal tip toward the most-distal longitudinal vibration node,
and a functional asymmetry which is asymmetric about the longitudinal
axis and which translates longitudinal ultrasonic vibrational movement
of the proximal end into a combination of a longitudinal ultrasonic
vibration and a transverse ultrasonic vibration in at least some
of the treatment portion of the ultrasonic-surgical-blade body,
wherein an amplitude of the transverse ultrasonic vibration at the
distal tip is less than substantially ten percent of a maximum amplitude
of the transverse ultrasonic vibration of the treatment portion
of the ultrasonic-surgical-blade body.
2. The ultrasonic surgical blade of claim 1 wherein the ultrasonic-surgical-blade
body has a curved shape distal the most-distal longitudinal vibration
node, and wherein the curved shape defines the functional asymmetry
of the ultrasonic-surgical-blade body.
3. The ultrasonic surgical blade of claim 2 wherein the ultrasonic-surgical-blade
body has a concave-shaped top surface and a convex-shaped bottom
surface.
4. The ultrasonic surgical blade of claim 1 wherein the functional
asymmetry is chosen and disposed to make the amplitude of the transverse
ultrasonic vibration at the distal tip substantially zero.
5. The ultrasonic surgical blade of claim 1 wherein the functional
asymmetry is chosen and disposed to make the vector sum amplitude
of the amplitudes of the longitudinal and transverse ultrasonic
vibrations, between the distal tip and half way to the most-distal
longitudinal vibration node, substantially equal to the amplitude
of the longitudinal ultrasonic vibration at the distal tip.
6. The ultrasonic surgical blade of claim 1 wherein the functional
asymmetry is chosen and disposed to make the vector sum amplitude
of the amplitudes of the longitudinal and transverse ultrasonic
vibrations within plus or minus twenty-five percent of a particular
value over at least half the distance between the most-distal longitudinal
vibration node and the distal tip.
7. The ultrasonic surgical blade of claim 6 wherein the functional
asymmetry is chosen and disposed to make the vector sum amplitude
of the amplitudes of the longitudinal and transverse ultrasonic
vibrations within plus or minus ten percent of a particular value
over at least half the distance between the most-distal longitudinal
vibration node and the distal tip.
8. The ultrasonic surgical blade of claim 6 wherein the functional
asymmetry is chosen and disposed to make the vector sum amplitude
of the amplitudes of the longitudinal and transverse ultrasonic
vibrations be above a predetermined value over a greater distance
between the most-distal longitudinal vibration node and the distal
tip than without the ultrasonic-surgical-blade body having the functional
asymmetry.
9. The ultrasonic surgical blade of claim 1 wherein the functional
asymmetry is chosen and disposed to make the vector sum amplitude
of the amplitudes of the longitudinal and transverse ultrasonic
vibrations be above a predetermined value over a greater distance
between the most-distal longitudinal vibration node and the distal
tip than without the ultrasonic-surgical-blade body having the functional
asymmetry.
10. The ultrasonic surgical blade of claim 1 wherein the functional
asymmetry is chosen and disposed to make the vector sum amplitude
of the amplitudes of the longitudinal and transverse ultrasonic
vibrations substantially match a preselected profile of vector sum
amplitude versus distance between the most-distal longitudinal vibration
node and the distal tip.
11. An ultrasonic surgical blade comprising an ultrasonic-surgical-blade
body having a distal tip, a proximal end adapted for longitudinal
ultrasonic vibrational excitation, a most-distal longitudinal vibration
node, a second-most-distal longitudinal vibration node, a treatment
portion extending from the distal tip toward the second most-distal
vibration node, at least one functional asymmetry, and at least
one balance asymmetry, wherein the at-least-one functional asymmetry
and the at-least-one balance asymmetry create a balance point, wherein
longitudinal ultrasonic vibrational movement of the proximal end
creates ultrasonic vibration of the ultrasonic-surgical-blade body
which is substantially purely longitudinal ultrasonic vibration
proximal the balance point and which is a combination of longitudinal
and transverse ultrasonic vibration distal the balance point and
in at least some of the treatment portion, and wherein an amplitude
of the transverse ultrasonic vibration at the distal tip is less
than substantially ten percent of a maximum amplitude of the transverse
ultrasonic vibration of the treatment portion of the ultrasonic-surgical-blade
body.
12. The ultrasonic surgical blade of claim 11 wherein the ultrasonic-surgical-blade
body has a curved shape which defines the at-least-one functional
asymmetry of the ultrasonic-surgical blade body, and wherein the
at-least-one balance asymmetry includes a cutout in the ultrasonic-surgical-blade
body.
13. The ultrasonic surgical blade of claim 11 wherein the balance
point is disposed distal the second-most-distal longitudinal vibration
node.
14. The ultrasonic surgical blade of claim 13 wherein the balance
point is disposed distal the most-distal longitudinal vibration
node.
15. The ultrasonic surgical blade of claim 11 wherein the at-least-one
functional asymmetry and the at-least-one balance asymmetry are
chosen and disposed to make the vector sum amplitude of the amplitudes
of the longitudinal and transverse ultrasonic vibrations within
plus or minus twenty-five percent of a particular value over at
least half the distance between the most-distal longitudinal vibration
node and the distal tip.
16. The ultrasonic surgical blade of claim 15 wherein the at-least-one
functional asymmetry and the at-least-one balance asymmetry are
chosen and disposed to make the vector sum amplitude of the amplitudes
of the longitudinal and transverse ultrasonic vibrations within
plus or minus ten percent of a particular value over at least half
the distance between the most-distal longitudinal vibration node
and the distal tip.
17. The ultrasonic surgical blade of claim 15 wherein the at-least-one
functional asymmetry and the at-least-one balance asymmetry are
chosen and disposed to make the vector sum amplitude of the amplitudes
of the longitudinal and transverse ultrasonic vibrations be above
a predetermined value over a greater distance between the most-distal
longitudinal vibration node and the distal tip than without the
ultrasonic-surgical-blade body having the at-least-one functional
asymmetry and the at-least-one balance asymmetry.
18. The ultrasonic surgical blade of claim 11 wherein the at-least-one
functional asymmetry and the at-least-one balance asymmetry are
chosen and disposed to make the vector sum amplitude of the amplitudes
of the longitudinal and transverse ultrasonic vibrations be above
a predetermined value over a greater distance between the most-distal
longitudinal vibration node and the distal tip than without the
ultrasonic-surgical-blade body having the at-least-one functional
asymmetry and the at-least-one balance asymmetry.
19. The ultrasonic surgical blade of claim 11 wherein the at-least-one
functional asymmetry and the at-least-one balance asymmetry are
chosen and disposed to make the vector sum amplitude of the amplitudes
of the longitudinal and transverse ultrasonic vibrations substantially
match a preselected profile of vector sum amplitude versus distance
between the most-distal longitudinal vibration node and the distal
tip.
20. An ultrasonic surgical blade comprising an ultrasonic-surgical-blade
body having a distal tip, a proximal end adapted for longitudinal
ultrasonic vibrational excitation, a most-distal longitudinal vibration
node, a second-most-distal longitudinal vibration node, a treatment
portion extending from the distal tip toward the most-distal vibration
node, at least one functional asymmetry, and at least one balance
asymmetry, wherein the at-least-one functional asymmetry and the
at-least-one balance asymmetry create a balance point which is disposed
between the most-distal longitudinal vibration node and the second-most-distal
longitudinal vibration node, and wherein longitudinal ultrasonic
vibrational movement of the proximal end creates ultrasonic vibration
of the ultrasonic-surgical-blade body which is substantially purely
longitudinal ultrasonic vibration proximal the balance point and
which is a combination of longitudinal and transverse ultrasonic
vibration distal the balance point and in at least some of the treatment
portion of the ultrasonic-surgical-blade body.
21. The ultrasonic surgical blade of claim 20 wherein the ultrasonic-surgical-blade
body has a curved shape distal the second-most-distal longitudinal
vibration node, wherein the curved shape defines the at-least-one
functional asymmetry of the ultrasonic-surgical-blade body, and
wherein the at-least-one balance asymmetry includes a cutout in
the ultrasonic-surgical-blade body.
22. The ultrasonic surgical blade of claim 20 wherein the at-least-one
functional asymmetry and the at-least-one balance asymmetry are
chosen and disposed to make the vector sum amplitude of the amplitudes
of the longitudinal and transverse ultrasonic vibrations substantially
match a preselected profile of vector sum amplitude versus distance
between the second-most-distal longitudinal vibration node and the
distal tip.
Surgical blade description
REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the priority benefit of U.S.
provisional patent application Ser. No. 60/548337 filed on Feb.
27 2004 the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention is related generally to ultrasonic
surgical instruments, and more particularly to an ultrasonic surgical
blade.
BACKGROUND OF THE INVENTION
[0003] Ultrasonic surgical instruments are known which include
ultrasonic surgical blades. A handpiece of a known ultrasonic surgical
instrument includes an ultrasonic transducer which is powered by
an ultrasonic generator through a cable. An ultrasonic transmission
rod of the instrument has a first end and a second end. The first
end of the ultrasonic transmission rod is operatively connected
to the ultrasonic transducer. The second end of the ultrasonic transmission
rod is connected to, or is an integral proximal extension of, an
ultrasonic surgical blade. The ultrasonic surgical blade is activated
by the ultrasonic transmission rod providing longitudinal ultrasonic
vibration to the blade. Known blade shapes include straight blades
and curved blades and include blades that are symmetric and blades
that are asymmetric about a longitudinal axis or about a curved
centerline of the blade. Known blades are designed to provide substantially
purely longitudinal ultrasonic vibration along the blade. Exemplary
devices are described in U.S. Pat. Nos. 5322055 and 6325811
the contents of which are incorporated herein by reference.
[0004] A known ultrasonic surgical blade is a cylindrical blade
which has a distal tip, a most-distal vibration node (a vibration
node being a point of substantially zero displacement), and a second
most-distal vibration antinode (a vibration antinode being a point
of maximum displacement relative to all other points in a half wave),
wherein the most-distal vibration antinode is the distal tip. Longitudinal
ultrasonic vibration of the blade generates motion and heat in the
contacted tissue, wherein the heat primarily provides the means
for the blade to cut and/or coagulate patient tissue.
[0005] The amplitude of the longitudinal ultrasonic vibration of
a conventional ultrasonic surgical blade is zero at the most-distal
vibration node and rises along a cosine curve to a maximum at the
distal tip of the blade. Typically, an amplitude of at least 50%
of the maximum amplitude is required for effective cutting, and
the distance from the distal tip to such 50% point on the blade
can be considered to be the effective cutting length of the blade.
The blade is not considered useful beyond its effective cutting
length. The effective cutting length is about 13 mm for a straight
cylindrical titanium rod at a resonant frequency of about 55.5 kHz
and an amplitude of at least 55 microns.
[0006] Still, scientists and engineers continue to seek improved
ultrasonic surgical blades.
SUMMARY OF THE INVENTION
[0007] A first embodiment of an ultrasonic surgical blade of the
invention includes an ultrasonic-surgical-blade body. The ultrasonic-surgical-blade
body has a longitudinal axis, a distal tip, a proximal end adapted
for longitudinal ultrasonic vibrational excitation, a most-distal
longitudinal vibration node, a treatment portion extending from
the distal tip toward the most-distal longitudinal vibration node,
and a functional asymmetry. The functional asymmetry is asymmetric
about the longitudinal axis and translates longitudinal ultrasonic
vibrational movement of the proximal end into a combination of a
longitudinal ultrasonic vibration and a transverse ultrasonic vibration
in at least some of the treatment portion of the ultrasonic-surgical-blade
body. An amplitude of the transverse ultrasonic vibration at the
distal tip is less than substantially ten percent of a maximum amplitude
of the transverse ultrasonic vibration of the treatment portion
of the ultrasonic-surgical-blade body.
[0008] A first expression of a second embodiment of an ultrasonic
surgical blade of the invention includes an ultrasonic-surgical-blade
body. The ultrasonic-surgical-blade body has a distal tip, a proximal
end adapted for longitudinal ultrasonic vibrational excitation,
a most-distal longitudinal vibration node, a second-most-distal
longitudinal vibration node, a treatment portion extending from
the distal tip toward the second most-distal vibration node, at
least one functional asymmetry, and at least one balance asymmetry.
The at-least-one functional asymmetry and the at-least-one balance
asymmetry create a balance point. Longitudinal ultrasonic vibrational
movement of the proximal end creates ultrasonic vibration of the
ultrasonic-surgical-blade body which is substantially purely longitudinal
ultrasonic vibration proximal the balance point and which is a combination
of longitudinal and transverse ultrasonic vibration distal the balance
point and in at least some of the treatment portion. An amplitude
of the transverse ultrasonic vibration at the distal tip is less
than substantially ten percent of a maximum amplitude of the transverse
ultrasonic vibration of the treatment portion of the ultrasonic-surgical-blade
body.
[0009] A second expression of a second embodiment of an ultrasonic
surgical blade of the invention includes an ultrasonic-surgical-blade
body. The ultrasonic-surgical-blade body has a distal tip, a proximal
end adapted for longitudinal ultrasonic vibrational excitation,
a most-distal longitudinal vibration node, a second-most-distal
longitudinal vibration node, a treatment portion extending from
the distal tip toward the most-distal vibration node, at least one
functional asymmetry, and at least one balance asymmetry. The at-least-one
functional asymmetry and the at-least-one balance asymmetry create
a balance point. The balance point is disposed between the most-distal
longitudinal vibration node and the second-most-distal longitudinal
vibration node. Longitudinal ultrasonic vibrational movement of
the proximal end creates ultrasonic vibration of the ultrasonic-surgical-blade
body which is substantially purely longitudinal ultrasonic vibration
proximal the balance point and which is a combination of longitudinal
and transverse ultrasonic vibration distal the balance point and
in at least some of the treatment portion of the ultrasonic-surgical-blade
body.
[0010] Several benefits and advantages are obtained from one or
more of the embodiments and expressions of the invention. Applicants
determined that the magnitude, and not the direction, of the ultrasonic
vibration of an ultrasonic-surgical blade largely determined the
effect of the blade on patient tissue. Applicants realized that
transverse ultrasonic vibration of the treatment portion of the
blade was beneficial which was contrary to conventional blade design
which taught having substantially zero transverse vibration in the
treatment portion of the blade. Applicants discovered that designing
the ultrasonic-surgical-blade body to provide a combination of transverse
and longitudinal ultrasonic vibration in at least some of the treatment
portion of the ultrasonic-surgical-blade body yielded, in one example,
a total ultrasonic vibration whose amplitude was larger, and more
uniform, over a longer distance of the blade from the distal tip
toward the most-distal longitudinal vibration node than would be
achieved with a comparable blade conventionally designed to provide
the treatment portion with substantially only longitudinal ultrasonic
vibration. Also, an ultrasonic surgical blade can have a particular
tissue effect, offering advantages for particular surgical applications,
by designing a particular total (longitudinal and transverse) ultrasonic
vibration amplitude versus distance (from the most-distal longitudinal
vibration node) profile, as can be appreciated by those skilled
in the art.
[0011] The present invention has, without limitation, application
in robotic-assisted surgery.
BRIEF DESCRIPTION OF THE FIGURES
[0012] FIG. 1 is a schematic side view of a first embodiment of
an ultrasonic surgical blade of the invention; and
[0013] FIG. 2 is a schematic side view of a second embodiment of
an ultrasonic surgical blade of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Before explaining the present invention in detail, it should
be noted that the invention is not limited in its application or
use to the details of construction and arrangement of parts illustrated
in the accompanying drawings and description. The illustrative embodiments
of the invention may be implemented or incorporated in other embodiments,
variations and modifications, and may be practiced or carried out
in various ways. Furthermore, unless otherwise indicated, the terms
and expressions employed herein have been chosen for the purpose
of describing the illustrative embodiments of the present invention
for the convenience of the reader and are not for the purpose of
limiting the invention.
[0015] It is understood that any one or more of the following-described
embodiments, expressions, examples, etc. can be combined with any
one or more of the other following-described embodiments, expressions,
examples, etc.
[0016] Referring now to the Figures, FIG. 1 illustrates a first
embodiment of an ultrasonic surgical blade 10 of the invention.
The ultrasonic surgical blade 10 includes an ultrasonic-surgical-blade
body 12. The ultrasonic-surgical-blade body 12 has a longitudinal
axis 14 a distal tip 16 a proximal end 18 adapted for longitudinal
ultrasonic vibrational excitation, a most-distal longitudinal vibration
node 20 a treatment portion 22 extending from the distal tip 16
toward the most-distal vibration node 20 and a functional asymmetry
24 which is asymmetric about the longitudinal axis 14 and which
translates longitudinal ultrasonic vibrational movement of the proximal
end 18 into a combination of a longitudinal ultrasonic vibration
and a transverse ultrasonic vibration in at least some of the treatment
portion 22 of the ultrasonic-surgical-blade body 12 wherein an
amplitude of the transverse ultrasonic vibration at the distal tip
16 is less than substantially ten percent of a maximum amplitude
of the transverse ultrasonic vibration of the treatment portion
22 of the ultrasonic-surgical-blade body 12.
[0017] For purposes of describing the invention, the treatment
portion of the blade is that blade portion extending from the distal
tip 16 toward the most-distal longitudinal vibration node 20 and
having a vector sum amplitude of the amplitudes of the longitudinal
and transverse ultrasonic vibrations of at least 50% of the maximum
vector sum amplitude between and including the distal tip 16 and
the most-distal longitudinal vibration node 20.
[0018] Functional asymmetries are described in U.S. Pat. No. 6328751
which is herein incorporated by reference. In one example of the
embodiment of FIG. 1 the ultrasonic-surgical-blade body 12 has
a curved shape distal the most-distal longitudinal vibration node
20 and the curved shape defines the functional asymmetry 24 of
the ultrasonic-surgical-blade body 12. In one variation, the ultrasonic-surgical-blade
body 12 has a concave-shaped top surface 26 and a convex-shaped
bottom surface 28. In the same or another example, the ultrasonic-surgical-blade
body 12 has at least two functional asymmetries.
[0019] In one enablement of the embodiment of FIG. 1 the functional
asymmetry 24 is chosen and disposed to make the amplitude of the
transverse ultrasonic vibration at the distal tip 16 substantially
zero. In the same or a different enablement, the functional asymmetry
24 is chosen and disposed to make the vector sum amplitude of the
amplitudes of the longitudinal and transverse ultrasonic vibrations,
between the distal tip 16 and half way to the most-distal longitudinal
vibration node 20 substantially equal to the amplitude of the longitudinal
ultrasonic vibration at the distal tip 16. In the same or a different
enablement, the functional asymmetry 24 is chosen and disposed to
make the vector sum amplitude of the amplitudes of the longitudinal
and transverse ultrasonic vibrations within plus or minus twenty-five
percent of a particular value over at least half the distance between
the most-distal longitudinal vibration node 20 and the distal tip
16. In one variation, the functional asymmetry 24 is chosen and
disposed to make the vector sum amplitude of the amplitudes of the
longitudinal and transverse ultrasonic vibrations within plus or
minus ten percent of a particular value over at least half the distance
between the most-distal longitudinal vibration node 20 and the distal
tip 16. In the same or a different enablement, the functional asymmetry
24 is chosen and disposed to make the vector sum amplitude of the
amplitudes of the longitudinal and transverse ultrasonic vibrations
be above a predetermined value over a greater distance between the
most-distal longitudinal vibration node 20 and the distal tip 16
than without the ultrasonic-surgical-blade body 12 having the functional
asymmetry 24. In the same or a different enablement, the functional
asymmetry 24 is chosen and disposed to make the vector sum amplitude
of the amplitudes of the longitudinal and transverse ultrasonic
vibrations substantially match a preselected profile of vector sum
amplitude versus distance between the most-distal longitudinal vibration
node 20 and the distal tip 16. Such choosing and disposing of functional
asymmetries to accomplish the above-described results are within
the level of skill of the artisan.
[0020] In one construction of the embodiment of FIG. 1 the ultrasonic-surgical-blade
body 12 consists essentially of titanium. In other constructions,
blade bodies consist essentially of aluminum, a ceramic, sapphire,
or any other material that transmits ultrasound in an efficient
manner. In one application, not shown, an ultrasonic transmission
rod is an integral proximal extension of the proximal end 18 of
the ultrasonic-surgical-blade body 12 and is longitudinally ultrasonically
vibrated by an ultrasonic transducer powered by an ultrasonic generator
through a cable.
[0021] In one implementation of the embodiment of FIG. 1 the maximum
amplitude of the transverse ultrasonic vibration of the treatment
portion 22 of the ultrasonic-surgical-blade body 12 is greater than
substantially 50 percent of the maximum amplitude of the longitudinal
ultrasonic vibration of the treatment portion 22. In one variation,
the maximum amplitude of the transverse ultrasonic vibration of
the treatment portion 22 is greater than substantially 90 percent
of the maximum amplitude of the longitudinal ultrasonic vibration
of the treatment portion 22. In the same or a different implementation,
a point on the blade body 12 in the treatment portion 22 has an
amplitude of transverse ultrasonic vibration which is greater than
the amplitude of longitudinal ultrasonic vibration.
[0022] FIG. 2 illustrates a second embodiment of the invention.
A first expression of the embodiment of FIG. 2 is for an ultrasonic
surgical blade 30 having an ultrasonic-surgical-blade body 32. The
ultrasonic-surgical-blade body 32 has a distal tip 34 a proximal
end 36 adapted for longitudinal ultrasonic vibrational excitation,
a most-distal longitudinal vibration node 38 a second-most-distal
longitudinal vibration node 40 a treatment portion 42 extending
from the distal tip 34 toward the second most-distal vibration node
40 at least one functional asymmetry 44 and at least one balance
asymmetry 46. The at-least-one functional asymmetry 44 and the at-least-one
balance asymmetry 46 create a balance point 48. Longitudinal ultrasonic
vibrational movement of the proximal end 36 creates ultrasonic vibration
of the ultrasonic-surgical-blade body 32 which is substantially
purely longitudinal ultrasonic vibration proximal the balance point
48 and which is a combination of longitudinal and transverse ultrasonic
vibration distal the balance point 48 and in at least some of the
treatment portion 42. An amplitude of the transverse ultrasonic
vibration at the distal tip 34 is less than substantially ten percent
of a maximum amplitude of the transverse ultrasonic vibration of
the treatment portion 42 of the ultrasonic-surgical-blade body 32.
[0023] Balance asymmetries are also described in U.S. Pat. No.
6328751 previously incorporated herein by reference. In one example
of the first expression of the embodiment of FIG. 2 the at-least-one
balance asymmetry 46 includes a cutout. In the same or a different
example, the balance point 48 is disposed distal the second-most-distal
longitudinal vibration node 40. In one variation, not shown, the
balance point 48 is disposed distal the most-distal longitudinal
vibration node 38. In the same or a different example, the ultrasonic-surgical-blade
body 32 has a curved shape which defines the at-least-one functional
asymmetry 44 of the ultrasonic-surgical-blade body 32 and the at-least-one
balance asymmetry 46 includes a cutout in the ultrasonic-surgical-blade
body 32.
[0024] In one enablement of the first expression of the embodiment
of FIG. 2 the at-least-one functional asymmetry 44 and the at-least-one
balance asymmetry 46 are chosen and disposed to make the vector
sum amplitude of the amplitudes of the longitudinal and transverse
ultrasonic vibrations within plus or minus twenty-five percent of
a particular value over at least half the distance between the most-distal
longitudinal vibration node 38 and the distal tip 34. In one variation,
the at-least-one functional asymmetry 44 and the at-least-one balance
asymmetry 46 are chosen and disposed to make the vector sum amplitude
of the amplitudes of the longitudinal and transverse ultrasonic
vibrations within plus or minus ten percent of a particular value
over at least half the distance between the most-distal longitudinal
vibration node 38 and the distal tip 34. In the same or a different
enablement, the at-least-one functional asymmetry 44 and the at-least-one
balance asymmetry 46 are chosen and disposed to make the vector
sum amplitude of the amplitudes of the longitudinal and transverse
ultrasonic vibrations be above a predetermined value over a greater
distance between the most-distal longitudinal vibration node 38
and the distal tip 34 than without the ultrasonic-surgical-blade
body 32 having the at-least-one functional asymmetry 44 and the
at-least-one balance asymmetry 46. In the same or a different enablement,
the at-least-one functional asymmetry 44 and the at-least-one balance
asymmetry 46 are chosen and disposed to make the vector sum amplitude
of the amplitudes of the longitudinal and transverse ultrasonic
vibrations substantially match a preselected profile of vector sum
amplitude versus distance between the most-distal longitudinal vibration
node 38 and the distal tip 34. Such choosing and disposing of functional
asymmetries 44 and balance asymmetries 46 to accomplish the above-described
results are within the level of skill of the artisan.
[0025] A second expression of the embodiment of FIG. 2 is for an
ultrasonic surgical blade 30 having an ultrasonic-surgical-blade
body 32. The ultrasonic-surgical-blade body 32 has a distal tip
34 a proximal end 36 adapted for longitudinal ultrasonic vibrational
excitation, a most-distal longitudinal vibration node 38 a second-most-distal
longitudinal vibration node 40 a treatment portion 42 extending
from the distal tip 34 toward the most-distal vibration node 38
at least one functional asymmetry 44 and at least one balance asymmetry
46. The at-least-one functional asymmetry 44 and the at-least-one
balance asymmetry 46 create a balance point 48 which is disposed
between the most-distal longitudinal vibration node 38 and the second-most-distal
longitudinal vibration node 40. Longitudinal ultrasonic vibrational
movement of the proximal end 36 creates ultrasonic vibration of
the ultrasonic-surgical-blade body 32 which is substantially purely
longitudinal ultrasonic vibration proximal the balance point 48
and which is a combination of longitudinal and transverse ultrasonic
vibration distal the balance point 48 and in at least some of the
treatment portion 42 of the ultrasonic-surgical-blade body 32.
[0026] In one example of the second expression of the embodiment
of FIG. 2 the ultrasonic-surgical-blade body 32 has a curved shape
distal the second-most-distal longitudinal vibration node 40 and
the curved shape defines the at-least-one functional asymmetry 44
of the ultrasonic-surgical-blade body 32. In this example, the at-least-one
balance asymmetry 46 includes a cutout in the ultrasonic-surgical-blade
body 32. In one enablement of the second expression of the embodiment
of FIG. 2 the at-least-one functional asymmetry 44 and the at-least-one
balance asymmetry 46 are chosen and disposed to make the vector
sum amplitude of the amplitudes of the longitudinal and transverse
ultrasonic vibrations substantially match a preselected profile
of vector sum amplitude versus distance between the second-most-distal
longitudinal vibration node 40 and the distal tip 34.
[0027] Several benefits and advantages are obtained from one or
more of the embodiments and expressions of the invention. Applicants
determined that the magnitude, and not the direction, of the ultrasonic
vibration of an ultrasonic-surgical blade largely determined the
effect of the blade on patient tissue. Applicants realized that
transverse ultrasonic vibration of the treatment portion of the
blade was beneficial which was contrary to conventional blade design
which taught having substantially zero transverse vibration in the
treatment portion of the blade. Applicants discovered that designing
the ultrasonic-surgical-blade body to provide a combination of transverse
and longitudinal ultrasonic vibration in at least some of the treatment
portion of the ultrasonic-surgical-blade body yielded, in one example,
a total ultrasonic vibration whose amplitude was larger, and more
uniform, over a longer distance of the blade from the distal tip
toward the most-distal longitudinal vibration node than would be
achieved with a comparable blade conventionally designed to provide
the treatment portion with substantially only longitudinal ultrasonic
vibration. Also, an ultrasonic surgical blade can have a particular
tissue effect, offering advantages for particular surgical applications,
by designing a particular total (longitudinal and transverse) ultrasonic
vibration amplitude versus distance (from the most-distal longitudinal
vibration node) profile, as can be appreciated by those skilled
in the art.
[0028] The foregoing description of several embodiments and expressions
of the invention has been presented for purposes of illustration.
It is not intended to be exhaustive or to limit the invention to
the precise forms disclosed, and obviously many modifications and
variations are possible in light of the above teaching. For example,
as would be apparent to those skilled in the art, the disclosures
herein of the ultrasonic surgical blade have equal application in
robotic assisted surgery taking into account the obvious modifications
of such systems and components to be compatible with such a robotic
system.
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