U.S. patent application number 11/784715 was filed with the patent office on 2007-10-04 for medical ultrasound system and handpiece and methods for making and tuning.
Invention is credited to Karen M. Kowalski, Michael J. Stokes, Foster B. Stulen, Eitan T. Wiener.
Application Number | 20070232926 11/784715 |
Document ID | / |
Family ID | 37963147 |
Filed Date | 2007-10-04 |
United States Patent
Application |
20070232926 |
Kind Code |
A1 |
Stulen; Foster B. ; et
al. |
October 4, 2007 |
Medical ultrasound system and handpiece and methods for making and
tuning
Abstract
Several embodiments of medical ultrasound handpieces are
described each including a medical ultrasound transducer assembly.
An embodiment of a medical ultrasound system is described, wherein
the medical ultrasound system includes a medical ultrasound
handpiece having a medical ultrasound transducer assembly and
includes an ultrasonically-vibratable medical-treatment instrument
which is attachable to a distal end of the transducer assembly. An
embodiment of a medical ultrasound system is described, wherein the
medical ultrasound system has a handpiece including a medical
ultrasound transducer assembly and including a housing or housing
component surrounding the transducer assembly. A method for tuning
a medical ultrasound handpiece includes machining at least a distal
non-threaded portion of an instrument-attachment stud of the
transducer assembly to match a measured fundamental frequency to a
desired fundamental frequency to within a predetermined limit. A
method for making a medical ultrasound transducer assembly
determines acceptable gains for gain stages of the transducer
assembly.
Inventors: |
Stulen; Foster B.; (Mason,
OH) ; Wiener; Eitan T.; (Cincinnati, OH) ;
Kowalski; Karen M.; (Burlington, KY) ; Stokes;
Michael J.; (Cincinnati, OH) |
Correspondence
Address: |
THOMPSON HINE L.L.P.;Intellectual Property Group
P.O. BOX 8801
DAYTON
OH
45401-8801
US
|
Family ID: |
37963147 |
Appl. No.: |
11/784715 |
Filed: |
April 9, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11545784 |
Oct 10, 2006 |
|
|
|
11784715 |
Apr 9, 2007 |
|
|
|
60726625 |
Oct 14, 2005 |
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Current U.S.
Class: |
600/459 |
Current CPC
Class: |
A61B 2017/320088
20130101; A61B 8/4455 20130101; A61B 2017/320089 20170801; A61B
2017/320071 20170801; B06B 1/0618 20130101; A61B 17/320068
20130101; A61B 2017/22018 20130101 |
Class at
Publication: |
600/459 |
International
Class: |
A61B 8/14 20060101
A61B008/14 |
Claims
1-30. (canceled)
31. A medical ultrasound system comprising: a) a medical ultrasound
transducer assembly which has a gain of unity and which has a
distal end portion; and b) an ultrasonically-vibratable
medical-treatment instrument which is attachable to the distal end
portion of the transducer assembly and which has at least one gain
stage.
32. The medical ultrasound system of claim 31, wherein the
at-least-one gain stage includes a plurality of gain stages.
33. The medical ultrasound system of claim 32, wherein the
transducer assembly includes a stacked plurality of piezoelectric
transducer disks.
34. A medical ultrasound system comprising: a) a medical ultrasound
transducer assembly which has a distal end portion; and b) an
ultrasonically-vibratable medical-treatment instrument which is
attachable to the distal end portion of the transducer assembly,
wherein the transducer assembly and the attached instrument
together have an operating wavelength, wherein the transducer
assembly alone has a length which is at least equal to 1/4 of the
operating wavelength and which is less than 1/2 of the operating
wavelength, and wherein the transducer assembly and the attached
instrument together have a length equal to N times 1/2 of the
operating wavelength, wherein N is a non-zero positive whole
number.
35. The medical ultrasound system of claim 34, wherein N equals
one.
36. The medical ultrasound system of claim 35, wherein the
transducer assembly and the attached instrument together have a
node, and wherein the transducer assembly includes the node.
37. The medical ultrasound system of claim 36, wherein the
transducer assembly includes a stacked plurality of piezoelectric
transducer disks.
38. A medical ultrasound handpiece comprising a medical ultrasound
transducer assembly, wherein the transducer assembly has proximal
and distal nodes, wherein the transducer assembly has a first
transducer-assembly-to-housing mounting feature disposed proximate
the proximal node and a second transducer-assembly-to-housing
mounting feature disposed proximate the distal node, and wherein
the transducer assembly lacks any additional
transducer-assembly-to-housing mounting feature.
39. The medical ultrasound handpiece of claim 38, also including a
housing having an opening and surrounding the transducer assembly,
wherein the transducer assembly is insertable into the housing
through the opening.
40. The medical ultrasound system of claim 39, wherein the
transducer assembly includes a stacked plurality of piezoelectric
disks.
41-65. (canceled)
66. The medical ultrasound system of claim 33, wherein each gain
stage has a proximal end disposed proximate a corresponding node of
the instrument and has a distal end disposed proximate a
corresponding antinode of the instrument.
67. The medical ultrasound system of claim 32, wherein each gain
stage has a proximal end disposed proximate a corresponding node of
the instrument and has a distal end disposed proximate a
corresponding antinode of the instrument.
68. The medical ultrasound system of claim 34, wherein the
transducer assembly and the attached instrument together have a
node, wherein the transducer assembly includes the node, wherein
the transducer assembly includes a stacked plurality of
piezoelectric transducer disks, and wherein the transducer assembly
includes a flange disposed proximate the node.
69. The medical ultrasound system of claim 68, wherein the flange
is disposed proximal the node, wherein the instrument is attached
to the flange, and wherein the stacked plurality of piezoelectric
transducer disks is disposed proximal and abutting the flange.
70. The medical ultrasound system of claim 68, wherein the flange
is disposed distal the node, wherein the instrument is attached to
the flange, and wherein the stacked plurality of piezoelectric
transducer disks is disposed proximal and abutting the flange.
71. The medical ultrasound system of claim 68, wherein the flange
is substantially centered at the node, wherein the instrument is
attached to the flange, wherein the stacked plurality of
piezoelectric transducer disks is disposed proximal and abutting
the flange, and wherein the transducer assembly includes an
additional stacked plurality of piezoelectric transducer disks
disposed distal and abutting the flange.
72. The medical ultrasound system of claim 39, wherein the first
transducer-to-housing mounting feature is a first outward flange of
the transducer assembly and the second
transducer-assembly-to-housing mounting feature is a second outward
flange of the transducer assembly.
73. The medical ultrasound system of claim 39, wherein the first
transducer-to-housing mounting feature is a first outward flange of
the transducer assembly and the second
transducer-assembly-to-housing mounting feature is an O-ring groove
of the transducer assembly.
74. The medical ultrasound system of claim 39, wherein the first
transducer-to-housing mounting feature is an O-ring groove of the
transducer assembly and the second transducer-assembly-to-housing
mounting feature is an outward flange of the transducer
assembly.
75. The medical ultrasound system of claim 39, wherein the first
transducer-to-housing mounting feature is a first O-ring groove of
the transducer assembly and the second
transducer-assembly-to-housing mounting feature is a second O-ring
groove of the transducer assembly.
76. The medical ultrasound system of claim 39, wherein the first
transducer-to-housing mounting feature is a first pair of
O-ring-bounding outward flanges of the transducer assembly and the
second transducer-assembly-to-housing mounting feature is a second
pair of O-ring-bounding outward flanges of the transducer assembly.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the priority benefit of U.S.
provisional patent application Ser. No. 60/726,625, filed on Oct.
14, 2005.
FIELD OF THE INVENTION
[0002] The present invention is related generally to medical
equipment, and more particularly to a medical ultrasound handpiece
having a medical ultrasound transducer assembly, to a method for
tuning the handpiece, to a method for making the transducer
assembly, and to a medical ultrasound system including a handpiece
and an ultrasonically-vibratable medical-treatment instrument which
is attachable to the distal end portion of the transducer assembly
of the handpiece.
BACKGROUND OF THE INVENTION
[0003] Medical ultrasound systems are known which include a medical
ultrasound handpiece having a medical ultrasound transducer
assembly and which include an ultrasonically-vibratable
medical-treatment instrument attached to the distal end portion of
the transducer assembly of the handpiece. Examples of such
instruments include an ultrasonically vibrating scalpel and include
an ultrasonic clamp having a first clamp arm which is an
ultrasonically vibrating blade and having a second non-vibrating
clamp arm. In one known application, the scalpel/blade vibrates at
a fundamental frequency (i.e., a resonant frequency of displacement
along the longitudinal axis of the instrument).
[0004] Conventional medical ultrasound systems provide the
instrument with a desirable high displacement (i.e., a large
vibrational amplitude) by employing a relatively large size
transducer assembly resulting in a relatively large size handpiece
which is unsuitable for a surgeon to hold and use in precise and
delicate surgery.
[0005] Still, scientists and engineers continue to seek improved
medical ultrasound handpieces having a medical ultrasound
transducer assembly and improved systems and methods related
thereto.
SUMMARY
[0006] A first expression of a first embodiment of the invention is
for a medical ultrasound handpiece including a medical ultrasound
transducer assembly. The transducer assembly includes consecutive
first and second half-wave sections, wherein the first half-wave
section includes a first node and the second half-wave section
includes a second node. The first half-wave section includes a
first piezoelectric transducer disk substantially centered about
the first node, and the second half-wave section includes a second
piezoelectric transducer disk substantially centered about the
second node. The transducer assembly includes a gain stage located
between the first and second piezoelectric transducer disks.
[0007] A first expression of a second embodiment of the invention
is for a medical ultrasound handpiece including a medical
ultrasound transducer assembly. The transducer assembly includes
consecutive first and second half-wave sections, wherein the first
half-wave section includes a first node and the second half-wave
section includes a second node. The first half-wave section
includes a first stacked plurality of piezoelectric transducer
disks substantially centered about the first node, and the second
half-wave section includes a second stacked plurality of
piezoelectric transducer disks substantially centered about the
second node. The transducer assembly includes a gain stage located
between the first and second stacked pluralities of piezoelectric
transducer disks.
[0008] A second expression of a second embodiment of the invention
is for a medical ultrasound handpiece including a 11/2-wave medical
ultrasound transducer assembly. The transducer assembly includes
consecutive first, second, and distal-most third half-wave
sections, wherein the first half-wave section includes a first
node, the second half-wave section includes a second node, and the
third half-wave section includes a third node. The first half-wave
section includes a first stacked plurality of piezoelectric
transducer disks substantially centered about the first node, and
the second half-wave section includes a second stacked plurality of
piezoelectric transducer disks substantially centered about the
second node. The transducer assembly includes a first, second, and
third gain stages. The first gain stage is located in the first
half-wave section distal the first stacked plurality of
piezoelectric transducer disks. The second gain stage is located in
the second half-wave section distal the second stacked plurality of
piezoelectric transducer disks. The third gain stage extends
distally from proximate the third node.
[0009] A first expression of a third embodiment of the invention is
for a medical ultrasound handpiece including a 1-wave medical
ultrasound transducer assembly. The transducer assembly includes
consecutive first and distal-most second half-wave sections,
wherein the first half-wave section includes a first node and the
second half-wave section includes a second node. The first
half-wave section includes a first stacked plurality of
piezoelectric transducer disks, and the second half-wave section
includes a second stacked plurality of piezoelectric transducer
disks. The transducer assembly includes first and second gain
stages, wherein the first gain stage is located in the first
half-wave section distal the first stacked plurality of
piezoelectric transducer disks, and wherein the second gain stage
is located in the second half-wave section distal the second
stacked plurality of piezoelectric transducer disks.
[0010] A first expression of a fourth embodiment of the invention
is for a medical ultrasound handpiece including a 1/2-wave medical
ultrasound transducer assembly. The transducer assembly includes a
proximal antinode, a distal antinode, and a node located between
the proximal and distal antinodes. The transducer assembly includes
a first stacked plurality of piezoelectric transducer disks located
proximal the node, a second stacked plurality of piezoelectric
transducer disks located distal the node, and a gain stage located
distal the second stacked plurality of piezoelectric transducer
disks.
[0011] A first expression of a fifth embodiment of the invention is
for a medical ultrasound system including a medical ultrasound
transducer assembly and an ultrasonically-vibratable
medical-treatment instrument. The transducer assembly has a gain of
unity and has a distal end portion. The instrument is attachable to
the distal end portion of the transducer assembly and has at least
one gain stage.
[0012] A first expression of a sixth embodiment of the invention is
for a medical ultrasound system including a medical ultrasound
transducer assembly and an ultrasonically-vibratable
medical-treatment instrument. The transducer assembly has a distal
end portion. The instrument is attachable to the distal end portion
of the transducer assembly. The transducer assembly and the
attached instrument together have an operating wavelength. The
transducer assembly alone has a length which is at least equal to
1/4 of the operating wavelength and which is less than 1/2 of the
operating wavelength. The transducer assembly and the attached
instrument together have a length equal to N times 1/2 of the
operating wavelength, wherein N is a non-zero positive whole
number.
[0013] A first expression of a seventh embodiment of the invention
is for a medical ultrasound handpiece including a medical
ultrasound transducer assembly. The transducer assembly has first
and second nodes. The transducer assembly has a first
transducer-assembly-to-housing mounting feature located proximate
the first node and a second transducer-assembly-to-housing mounting
feature located proximate the second node. The transducer assembly
lacks any additional transducer-assembly-to-housing mounting
feature.
[0014] A first expression of an eighth embodiment of the invention
is for a medical ultrasound handpiece including a medical
ultrasound transducer assembly and an annular connector assembly.
The transducer assembly includes a metallic end-mass component, a
piezoelectric transducer disk, and an electrode. The piezoelectric
transducer disk is located distal the end-mass component and is in
electrical contact with the electrode. The connector assembly
surrounds the transducer assembly, is in electrical contact with
the electrode, and is electrically connectable to an ultrasound
electric generator.
[0015] A second expression of an eighth embodiment of the invention
is for a medical ultrasound handpiece including a medical
ultrasound transducer assembly and an annular connector assembly.
The transducer assembly includes a metallic end-mass component, a
stacked plurality of piezoelectric transducer disks, and
electrodes. The stacked plurality of piezoelectric transducer disks
is located distal the end-mass component. Each piezoelectric
transducer disk is in electrical contact with a corresponding
electrode. The connector assembly surrounds the transducer
assembly, is in electrical contact with the electrodes, and is
electrically connected to a cable socket which is electrically
connectable to an ultrasound electric generator.
[0016] A first expression of a ninth embodiment of the invention is
for a medical ultrasound handpiece including a medical ultrasound
transducer assembly, an inner conductive ring, and an outer
conductive ring. The transducer assembly is electrically
connectable to an ultrasound electric generator, has a longitudinal
axis, and is attachable to an ultrasonically-vibratable
medical-treatment instrument having a switch which has an open
position and a closed position. The inner conductive ring is
substantially coaxially aligned with the longitudinal axis,
circumferentially surrounds the transducer assembly, and has a
distally-facing first annular surface. The outer conductive ring is
substantially coaxially aligned with the longitudinal axis,
circumferentially surrounds the transducer assembly, and has a
distally-facing second annular surface. The outer conductive ring
is electrically isolated from the inner conductive ring. The first
and second annular surfaces are in electric contact with the switch
of the attached instrument when the switch is in the closed
position. The inner and outer conductive rings are electrically
connectable to the generator, and the switch of the attached
instrument controls the connected generator.
[0017] A first expression of a tenth embodiment of the invention is
for a medical ultrasound handpiece including a medical ultrasound
transducer assembly, a housing, a mount, and an annular bumper
unit. The housing surrounds the transducer assembly. The mount
pivotally attaches the transducer assembly to the housing. The
bumper unit is attached to the housing and includes a plurality of
spaced apart and inwardly projecting bumpers. None of the bumpers
is in contact with the transducer assembly when the transducer
assembly is not under a pivoting load. At least one of the bumpers
is contact with the transducer assembly when the transducer
assembly is under the pivoting load.
[0018] A first expression of an eleventh embodiment of the
invention is for a medical ultrasound handpiece including a medical
ultrasound transducer assembly, at least one mounting member, and a
first housing component. The transducer assembly has a longitudinal
axis and has a substantially coaxially aligned, circumferential
surface groove. The at-least-one mounting member is
at-least-partially-annular and has an inner portion located in the
surface groove. The first housing component surrounds the
transducer assembly and has a distal end portion including an
annular longitudinally-facing surface with a recessed seat. The
at-least-one mounting member has at least a proximal portion
located in the seat.
[0019] Several benefits and advantages are obtained from one or
more of the expressions of embodiments of the invention. In one
example, one or more or all of the expressions of embodiments of
the invention help enable a relatively small size medical
ultrasound transducer assembly to provide an attached
ultrasonically-vibratable medical-treatment instrument with a
desirable high displacement (i.e., a large vibrational amplitude)
resulting in a relatively small size handpiece which is suitable
for a surgeon to hold and use in precise and delicate surgery.
BRIEF DESCRIPTION OF THE FIGURES
[0020] FIG. 1 is a schematic side elevational view of a first
embodiment of the invention showing consecutive first and second
half-wave sections of a medical ultrasound transducer assembly of a
medical ultrasound handpiece, wherein a first piezoelectric
transducer disk is substantially centered about a first node of the
first half-wave section and a second piezoelectric transducer disk
is substantially centered about a second node of the second
half-wave section;
[0021] FIG. 2 is a perspective view of a second embodiment of the
invention showing an assembled medical ultrasound handpiece
including the exposed stud of the 11/2-wave medical ultrasound
transducer assembly of the handpiece;
[0022] FIG. 3 is an exploded view of a portion of the handpiece of
FIG. 2 showing the medical ultrasound transducer assembly, the
bumper assembly, the housing, and the nose cone assembly of the
handpiece of FIG. 2;
[0023] FIG. 4 is a view of the transducer assembly, the bumper
assembly, and the nose cone assembly of FIG. 3, wherein the bumper
assembly and the nose cone assembly are shown attached to the
transducer assembly;
[0024] FIG. 5 is a perspective schematic view of the transducer
assembly of FIG. 4 showing first and second stacked pluralities of
piezoelectric transducer disks substantially centered about
respective first and second nodes;
[0025] FIG. 6 is an exploded view of the transducer assembly of
FIG. 5;
[0026] FIG. 7 is a perspective view of the stud of the transducer
assembly of FIG. 2 with an ultrasonically-vibratable
medical-treatment instrument attached thereto, wherein the
instrument is shown in partial cutaway, and wherein the instrument
is an ultrasonically vibratable scalpel;
[0027] FIG. 8 is a perspective distal end view of a portion of the
transducer assembly and of the nose cone assembly of FIG. 4;
[0028] FIG. 9 is a cross sectional view of the transducer assembly
and of the nose cone assembly of FIG. 8;
[0029] FIG. 10 a view of a portion of the transducer assembly of
FIG. 4 with the attached bumper assembly;
[0030] FIG. 11 is a cross sectional view of the bumper assembly of
FIG. 10;
[0031] FIG. 12 is a perspective view of a portion of the transducer
assembly and of the dielectric multi-lug ring, the dielectric
washer, and the first O-ring seal of the nose cone assembly of FIG.
9;
[0032] FIG. 13 is a perspective view of the transducer assembly of
FIG. 12;
[0033] FIG. 14 is a side elevational schematic view of an alternate
embodiment of a handpiece wherein the transducer assembly has first
and second gain stages each including a stacked plurality of
piezoelectric transducer disks;
[0034] FIG. 15 is a side elevational schematic view of a third
embodiment of the invention showing a 1-wave medical ultrasound
transducer assembly of a medical ultrasound handpiece and showing
an ultrasonically-vibratable medical-treatment instrument which is
attachable to the stud of the transducer assembly;
[0035] FIG. 16 is a side elevational schematic view of a fourth
embodiment of the invention showing a 11/2-wave medical ultrasound
transducer assembly of a medical ultrasound handpiece and showing
an ultrasonically-vibratable medical-treatment instrument which is
attachable to the stud of the transducer assembly;
[0036] FIG. 17 is a perspective view of a fifth embodiment of the
invention showing a medical ultrasound system including a medical
ultrasound transducer assembly having a unity-gain and including an
ultrasonically-vibratable medical-treatment instrument having four
gain stages;
[0037] FIG. 18 is a side elevational schematic view of a sixth
embodiment of the invention showing a medical ultrasound system
including a medical ultrasound transducer assembly and an
ultrasonically-vibratable medical-treatment instrument which
together have an operating wavelength, wherein the transducer
assembly alone has a length which is less than 1/2 of the operating
wavelength;
[0038] FIGS. 19 and 20 are side elevational schematic views of
alternate embodiments of the system of FIG. 18;
[0039] FIG. 21 is a side elevational schematic view of a seventh
embodiment of the invention showing a medical ultrasound handpiece
including a medical ultrasound transducer assembly and a housing,
wherein the transducer assembly has a first
transducer-assembly-to-housing mounting feature disposed proximate
a proximal node of the transducer assembly and has a second
transducer-assembly-to-housing mounting feature disposed proximate
a distal node of the transducer assembly;
[0040] FIGS. 22 through 25 are side elevational schematic views of
alternate embodiments of the transducer assembly of the handpiece
of FIG. 21;
[0041] FIG. 26 is a side elevational schematic view of an eighth
embodiment of the invention showing a medical ultrasound handpiece
connected to an ultrasound electric generator with the end cap and
the housing of the handpiece shown in cutaway;
[0042] FIG. 27 is an enlarged side elevational view of the annular
connector assembly and a portion of the medical ultrasound
transducer assembly of the handpiece of FIG. 26;
[0043] FIG. 28 is a perspective view of the end cap, the cable
socket, the annular connector assembly, and the medical ultrasound
transducer assembly of the handpiece of FIG. 26;
[0044] FIG. 29 is an exploded view of the assemblage of FIG.
28;
[0045] FIG. 30 is a schematic view of a ninth embodiment of the
invention showing a medical ultrasound handpiece connected to an
ultrasound electric generator, wherein portions of the handpiece
are shown in cutaway;
[0046] FIG. 31 is a cross sectional view of the transducer assembly
of the handpiece of FIG. 30 taken along lines 31-31 of FIG. 30;
[0047] FIG. 32 is a perspective view of a distal end portion of the
handpiece of FIG. 30 connected to a proximal end portion of an
ultrasonically-vibratable medical-treatment instrument which
includes a switch which controls the generator;
[0048] FIG. 33 is a perspective view of a tenth embodiment of the
invention showing a medical ultrasound handpiece including a
housing (shown in cutaway), a medical ultrasound transducer
assembly, a mount (shown in cutaway) pivotally attaching the
transducer assembly to the housing, and a bumper unit attached to
the housing;
[0049] FIG. 34 is a proximal end view of the transducer assembly
and the bumper unit of FIG. 33 when the mount is not under a
pivoting load;
[0050] FIG. 35 is a proximal end view of the transducer assembly
and the bumper unit of FIG. 33 when the mount is under a pivoting
load;
[0051] FIG. 36 is a perspective view of an eleventh embodiment of
the invention showing a medical ultrasound handpiece;
[0052] FIG. 37 is an exploded view of the handpiece of FIG. 36
showing the medical ultrasound transducer assembly (which is
schematically illustrated), the at-least-one mounting member, the
first housing component, and the second housing component of the
handpiece of FIG. 36;
[0053] FIGS. 38-40 are perspective views showing intermediate
stages of assembling the components of FIG. 37 to produce the
assembled handpiece of FIG. 36;
[0054] FIG. 41 is a cross sectional view of a distal portion of the
handpiece of FIG. 36; and
[0055] FIG. 42 is a distal end view of the first housing component
of FIG. 37.
DETAILED DESCRIPTION
[0056] Before explaining the several embodiments of the present
invention in detail, it should be noted that each embodiment is not
limited in its application or use to the details of construction
and arrangement of parts and steps 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.
[0057] It is further understood that any one or more of the
following-described expressions, embodiments, examples, etc. can be
combined with any one or more of the other following-described
expressions, embodiments, examples, etc.
[0058] A first embodiment of the invention is shown in FIG. 1. A
first expression of the embodiment of FIG. 1 is for a medical
ultrasound handpiece 10 including a medical ultrasound transducer
assembly 12. The transducer assembly 12 includes consecutive first
and second half-wave sections 14 and 16, wherein the first
half-wave section 14 includes a first node 18 and the second
half-wave section 16 includes a second node 20. The first half-wave
section 14 includes a first piezoelectric transducer disk 22
substantially centered about the first node 18, and the second
half-wave section 16 includes a second piezoelectric transducer
disk 24 substantially centered about the second node 20. The
transducer assembly 12 includes a gain stage 26 disposed between
the first and second piezoelectric transducer disks 22 and 24.
[0059] It is noted, for the purpose of describing the various
embodiments of the invention, that a medical ultrasound transducer
assembly is a transducer assembly which ultrasonically vibrates an
ultrasonically-vibratable medical-treatment instrument (such as,
without limitation, an ultrasonic scalpel or an ultrasonic clamp),
when attached to the transducer assembly, in a mode of vibration at
a fundamental frequency (i.e., a fundamental resonant frequency),
that a node is a node of vibration (i.e., a location of zero
magnitude of vibration), and that an antinode is a location of
maximum magnitude of vibration. Examples of modes of vibration
include, without limitation, a longitudinal mode of vibration, a
torsional mode of vibration, a bending mode of vibration, and a
swelling mode of vibration, wherein the transducer assembly is not
limited to operating in a single mode of vibration as is known to
those skilled in the art. Also, the terminology "gain stage" means
a positive gain stage and is a longitudinally-extending portion of
the transducer assembly which results in increased magnitude of
vibration. Gain stages may be provided by a portion of the
transducer assembly having at least one of a reduced diameter (as
identified in some of the figures), a (constant or non-constant)
taper, or being of a different material, as is known to those
skilled in the art. It is pointed out that piezoelectric transducer
disks are not limited to those with an outer perimeter having a
circular shape and may include those with an outer perimeter having
another shape such as, without limitation, an elliptical shape.
[0060] A second embodiment of the invention is shown in FIGS. 2-13.
A first expression of the embodiment of FIGS. 2-13 is for a medical
ultrasound handpiece 28 including a medical ultrasound transducer
assembly 30. The transducer assembly 30 includes consecutive first
and second half-wave sections 32 and 34, wherein the first
half-wave section 32 includes a first node 36 and the second
half-wave section 34 includes a second node 38. The first half-wave
section 32 includes a first stacked plurality 40 of piezoelectric
transducer disks 42 substantially centered about the first node 36,
and the second half-wave section 34 includes a second stacked
plurality 44 of piezoelectric transducer disks 42 substantially
centered about the second node 38. The transducer assembly 30
includes a gain stage 46 (also called a first gain stage) disposed
between the first and second stacked pluralities 40 and 44 of
piezoelectric transducer disks 42.
[0061] It is noted that, in one example, an electrode is disposed
between adjacent piezoelectric transducer disks of a stacked
plurality of piezoelectric transducer disks to energize the disks,
as is known to those skilled in the art.
[0062] In an alternate embodiment, as shown in FIG. 14, the
handpiece 48 includes a transducer assembly 50, wherein the gain
stage 52 (also called the first gain stage) of the transducer
assembly 50 includes a stacked plurality 54 of piezoelectric
transducer disks 42'. It is noted that the diameter of the
piezoelectric transducer disks 42' of the gain stage 52 is smaller
than the diameter of the piezoelectric transducer disks 42 of the
first stacked plurality 40. It is also noted that a decrease in
diameter at a node maximizes the gain of a gain stage, and that a
following increase in diameter at a distally adjacent antinode
fully keeps the gain of the gain stage.
[0063] A second expression of the embodiment of FIGS. 2-13 is for a
medical ultrasound handpiece 28 including a 11/2-wave medical
ultrasound transducer assembly 30'. The transducer assembly 30'
includes consecutive first, second, and distal-most third half-wave
sections 32, 34, and 56, wherein the first half-wave section 32
includes a first node 36, the second half-wave section 34 includes
a second node 38, and the third half-wave section 56 includes a
third node 58. The first half-wave section 32 includes a first
stacked plurality 40 of piezoelectric transducer disks 42
substantially centered about the first node 36, and the second
half-wave section 34 includes a second stacked plurality 44 of
piezoelectric transducer disks 42 substantially centered about the
second node 38. The transducer assembly 30 includes first, second,
and third gain stages 46, 60, and 62. The first gain stage 46 is
disposed in the first half-wave section 32 distal the first stacked
plurality 40 of piezoelectric transducer disks 42. The second gain
stage 60 is disposed in the second half-wave section 34 distal the
second stacked plurality 44 of piezoelectric transducer disks 42.
The third gain stage 62 extends distally from proximate the third
node 58.
[0064] It is noted that a 11/2-wave transducer assembly is a
transducer assembly having a length from its proximal end to its
distal end of substantially 11/2 wavelengths of its fundamental
frequency. It is also noted that a 11/2-wave transducer assembly
has a proximal antinode at its proximal end (the proximal end of
the first half-wave section), a common antinode of the first and
second half-wave sections, a common antinode of the second and
third half-wave sections, and a distal antinode at its distal end
(the distal end of the third half-wave section).
[0065] In one enablement of the second expression of the embodiment
of FIGS. 2-13, the first gain stage 46 has a proximal end 64 which
is distally spaced apart from the first stacked plurality 40 of
piezoelectric transducer disks 42 and has a distal end 65 which is
disposed proximate a common antinode 66 of the first and second
half-wave sections 32 and 34. In one variation, the second gain
stage 60 has a proximal end 68 which is distally spaced apart from
the second stacked plurality 44 of piezoelectric transducer disks
42 and has a distal end 70 which is disposed proximate a common
antinode 72 of the second and third half-wave sections 34 and 56.
In one modification, the third half-wave section 56 distally
terminates in a stud 74 which is attachable to an
ultrasonically-vibratable medical-treatment instrument 76. In one
example, the stud 74 includes a proximal threaded portion 78 and
includes a distal non-threaded portion 80 adjoining the proximal
threaded portion 78, and the proximal threaded portion 78 is
threadably attachable to the instrument 76. Examples of non-stud
and/or non-threadable attachments are left to those skilled in the
art.
[0066] In an alternate embodiment, as shown in FIG. 14, the first
gain stage 52 includes a stacked plurality 54 of piezoelectric
transducer disks 42', and the second gain stage 82 includes a
stacked plurality 84 of piezoelectric transducer disks 42'. In one
variation, the third half-wave section 86 includes a stacked
plurality 88 of piezoelectric transducer disks 42' having a
proximal end 90 which is distally spaced apart from the common
antinode 92 of the second and third half-wave sections 94 and 86
and having a distal end 96 which is disposed proximate the third
node 98.
[0067] A method for tuning the medical ultrasound handpiece 28
(wherein the handpiece 28 includes the stud 74) includes steps a)
through c). Step a) includes measuring a fundamental frequency of
the transducer assembly 30'. Step b) includes determining a desired
fundamental frequency of the transducer assembly 30' wherein the
desired fundamental frequency is greater than the measured
fundamental frequency. Step c) includes machining at least the
distal non-threaded portion 80 to match the measured fundamental
frequency to the desired fundamental frequency to within a
predetermined limit. In one variation, the machining of step c)
shortens the non-threaded portion 80. In one modification, step c)
also includes machining the proximal threaded portion 78. It is
noted that the method is not limited to a 11/2-wave transducer
assembly.
[0068] A method for making an example of the transducer assembly
30' of the medical ultrasound handpiece 28 includes steps a)
through g). In this method and example, there are first, second and
third gain stages 46, 60 and 62, the first, second and third gain
stages 46, 60 and 62 and the instrument 76 each have a gain, and
the transducer assembly 30' has a design diameter. Step a) includes
obtaining at least one electromechanical equation of an
electromechanical requirement, of drive circuitry to drive the
transducer assembly 30' with the attached instrument 76, which
depends on the design diameter and the first, second and third gain
stages 46, 60 and 62. Step b) includes obtaining at least one
acoustic equation of an acoustic requirement, of stable dynamic
behavior of the attached instrument 76, which depends on the design
diameter, the first, second and third gain stages 46, 60 and 62,
and the instrument gain. Step c) includes predetermining an
acceptable range for each electromechanical requirement. Step d)
includes predetermining an acceptable range for each acoustic
requirement. Step e) includes preselecting the design diameter and
the instrument gain. Step f) includes determining an acceptable
first gain for the first gain stage 46, an acceptable second gain
for the second gain stage 60, and an acceptable third gain for the
third gain stage 62 using the at-least-one electromechanical
equation and the at-least-one acoustic equation which place each
electromechanical requirement in the acceptable range for that
electromechanical requirement and each acoustic requirement in the
acceptable range for that acoustic requirement. Step g) includes
constructing the transducer assembly 30' with the first gain stage
46 having the determined acceptable first gain, with the second
gain stage 60 having the determined acceptable second gain, and
with the third gain stage 62 having the determined acceptable third
gain. It is noted that the design diameter is a basic diameter of
the transducer assembly and does not reflect any diameter of a gain
stage, any torquing flat on a component, any mounting flange of the
transducer assembly to a housing, any seat of a stud which engages
an instrument, and any diameter of a non-threaded portion of such
stud. It is also noted that the method is not limited to a
11/2-wave transducer assembly and/or to three gain stages and/or
particular component composition.
[0069] In one employment of the method for making the transducer
assembly 30', the attached instrument 76 has a fundamental
frequency. In this employment, step a) obtains an equation of the
phase margin of the attached instrument 76, an equation of the
power dissipation of the transducer assembly 30', an equation of
the displacement (linear or angular depending on the mode of
vibration) of the attached instrument 76, an equation of the
impedance of the transducer assembly 30', an equation of the power
transmitted to patient tissue (tissue power) by the attached
instrument 76, and an equation of the loaded maximum phase of the
attached instrument 76. It is noted that the phrase phase margin,
power dissipation, displacement, tissue power, impedance, and
loaded maximum phase are examples of electromechanical requirements
each having an acceptable range for drive circuitry in an
ultrasonic electric generator to drive the transducer assembly 30'
with the attached instrument 76. In this employment, step b)
obtains an equation of a first resonant frequency (Sn-1) next below
the fundamental frequency, obtains an equation of a second resonant
frequency (Sn+1) next above the fundamental frequency, and obtains
an equation of the span (Span-1) of the first and second resonant
frequencies. It is noted that Sn-1, Sn+1, and Span-1 are examples
of acoustic requirements each having an acceptable range for stable
dynamic behaviour of the attached instrument 76.
[0070] An example of a set of such at-least-one electromechanical
equation for the transducer assembly 30' is as follows: Phase
Margin=4284.8+72.71*DD-422.6*TG-2488.5*HG-505.74*MG+513.4*(HG).sup.2+26.1-
*(MG).sup.2-62.8*(DD*HG)+7.44*(DD*MG)+188.9*(TG*HG)+75.3*(HG*MG);
Power
Dissipation=21.22-0.905*DD-0.784*TG-12.3*HG5.7*MG+2.1*(HG).sup.2+0.11*(MG-
).sup.2+0.021*(DD*HG)+0.37*(DD*MG)+0.75*(TG*HG)+1.75*(HG*MG);
Displacement=70.62-7.15*DD-0.382*TG-26.44*HG-14.12*MG+2.29*(HG).sup.2-0.1-
2*(MG).sup.2+1.48*(DD*HG)+1.47*(DD*MG)+1.42*(TG*HG)+4.90*(HG*MG);
Tissue
Power=253.1+19.49*DD-17.6*TG-108.93*HG-40.8*MG+21.9*(HG).sup.2+4.5*(MG).s-
up.2-6.44*(DD*HG)-2.7*(DD*MG)+6.7*(TG*HG)+5.7*(HG*MG);
Impedance=194.82-8.31*DD-7.2*TG112.78*HG-52.1*MG+18.98*(HG).sup.2+0.97*(M-
G).sup.2+0.19*(DD*HG)+3.4*(DD*MG)+6.84*(TG*HG)+16.1*(HG*MG); and
Loaded Maximum
Phase=268.9+1.225*DD-6.5*TG-157.5*HG-38.7*MG+29.9*(HG).sup.2+3.23-
*(MG).sup.2.
[0071] An example of a set of such at-least-one acoustic equation
for the transducer assembly 30' is as follows:
Sn-1=163.5*DD+228.5*IG+4001.6*TG+2149.6*HG+860.3*MG+500.5*(IG).sup.2-1037-
.9*(IG*TG)-454.1*(IG*HG)-231.3*(IG*MG)-9125.7;
Sn+1=2805.6*DD-1590.3*IG+34.4*TG+1465.6*HG+2652.4*MG-168.1*(DD).sup.2+447-
.9*(IG).sup.2+138.2*(MG).sup.2-229.6*(IG*MG)-437.8*(HG*MG)-15212.6;
and
Span-1=3713.9*DD-2906.9*IG+2757.1*TG+274.7*HG+3160.6*MG-214.6*(DD).sup.2+-
976.2*(IG).sup.2-190*(MG).sup.2-672.5*(IG*TG)-460.9*(IG*MG)-19879.9.
[0072] In the above nine equations, the design diameter DD is the
diameter (in millimeters) of the end-mass component 100 (which is
equal to the outer diameter of the piezoelectric transducer disks
42 of the first and second stacked pluralities 40 and 44 of
piezoelectric transducer disks 42), IG is the instrument gain, the
trans gain TG is the first gain, the horn gain HG is the second
gain, and the mount gain MG is the third gain; It is noted that the
design diameter is also the basic diameter of the transducer
assembly 30' as shown in FIG. 5. The units for the phase margin are
Hertz, for the power dissipation are watts, for the displacement
are microns (peak-to-peak), for the tissue power are watts, for the
impedance are ohms, for the loaded maximum phase are degrees, for
Sn-1 are Hertz, for Sn+1 are Hertz, and for Span-1 are Hertz. The
above nine equations were developed for a particular example of the
transducer assembly 30' wherein a discussion of some of the
characteristics of the particular transducer assembly follows. The
particular transducer assembly 30' operated in a longitudinal mode
of vibration and included a metallic end-mass component 100
consisting essentially of stainless steel, a metallic
transducer-horn component 102 consisting essentially of titanium,
and a metallic horn-mount component 104 consisting essentially of
titanium. The particular transducer assembly included eight PZT
(piezoelectric transducer), type 8 material disks in each stack
(PZT disk dimensions were: outside diameter (DD in the equations);
4.2 mm inside diameter; and 2.34 mm thick). The PZT inside diameter
was 0.5 mm (millimeters) radially separated from the metal parts.
The stud had 6-32 USC threads. Each half wave was tuned to a
longitudinal fundamental frequency close to 55.5 KHz (kilo-Hertz).
Using the above nine equations, applicants successfully built and
tested a particular transducer assembly in which DD was chosen to
be 8 mm.
[0073] One technique for developing a similar set of nine equations
for a different transducer assembly including, for example and
without limitation, different component composition and/or a
different mode (or mixed modes) of vibration and/or piezoelectric
transducer disks with non-circular outer perimeters and/or a
transducer assembly having a different number of half-wave sections
and/or a transducer assembly having a different number of gain
stages, etc., is hereinafter described. Start by selecting a
statistical design such as Box-Behnken design of experiments, in
which: (1) the factors (i.e., independent variables) are the design
diameter of the transducer assembly, the gain stages of the
transducer assembly, and the instrument gain; (2) the responses for
acoustic (dynamic) performance (i.e., the acoustic-performance
independent variables) are Sn+1, Sn-1, and Span-1; and (3) the
responses for electromechanical performance (i.e., the
electromechanical independent variables) are impedance, phase
margin, tissue power, power dissipation, displacement and loaded
maximum phase. Create the experiment by selecting the ranges of
factors. Using commercial finite element analysis software such as
Abaqus, IDEAS etc., solve cases in the experiment for finite
element models of the transducer assembly. Analyze the data using
commercial statistical software such as Minitab to develop the
equations relating the responses to the factors. Simultaneously
solve the equations to size the gain stages for delivering a
desired acoustic performance with a particular attached instrument
and a desired electromechanical performance with a particular
connected generator. Using this methodology, a person skilled in
the art can develop equations, without undue experimentation, for
any transducer assembly including, for example, any fundamental
vibrational mode of interest (longitudinal, torsion, bending,
swelling etc.), any design cross section (including a non-circular
cross section), any PZT type, any metal used for metal parts, etc.
It is noted that, in a particular application, all equations of the
set of nine equations would or would not be used and/or at least
one different acoustic performance equation and/or different
electromechanical performance equation would be included. A person
skilled in the art may use different factors and responses in one
or both of the electromechanical performance and the acoustic
performance.
[0074] In a first design of the second expression of the embodiment
of FIGS. 2-13, the medical ultrasound handpiece 28 includes a
metallic end-mass component 100, a metallic transducer-horn
component 102, and a metallic horn-mount component 104. The
piezoelectric transducer disks 42 of the first and second stacked
pluralities 40 and 44 of piezoelectric transducer disks 42 are
annular disks, and the transducer-horn component 102 has proximal
and distal portions 106 and 108. The piezoelectric transducer disks
42 of the first stacked plurality 40 of piezoelectric transducer
disks 42 surround the proximal portion 106 of the transducer-horn
component 102, and the piezoelectric transducer disks 42 of the
second stacked plurality 44 of piezoelectric transducer disks 42
surround the distal portion 108 of the transducer-horn component
102.
[0075] In one variation of the first design, the transducer-horn
component 102 has an intermediate portion 110. The intermediate
portion 110 includes the first gain stage 46 and includes proximal
and distal seat portions 112 and 114 bounding the first gain stage
46. The end-mass component 100 is disposed proximal the first
stacked plurality 40 of piezoelectric transducer disks 42. The
end-mass component 100 is threadably attached to the proximal
portion 106 of the transducer-horn component 102 compressing the
first stacked plurality 40 of piezoelectric transducer disks 42
against the proximal seat portion 112. In one construction,
torquing flats on the end-mass component 100 and on the
transducer-horn component 102 facilitate such compression.
[0076] In one modification of the first design, the horn-mount
component 104 is disposed distal the second stacked plurality 44 of
piezoelectric transducer disks 42. The horn-mount component 104 is
threadably attached to the distal portion 108 of the
transducer-horn component 102 compressing the second stacked
plurality 44 of piezoelectric transducer disks 42 against the
distal seat portion 114. In one construction, torquing flats on the
horn-mount component 104 and on the transducer-horn component 102
facilitate such compression. In one example, the horn-mount
component 104 has a proximal portion 116 which includes the second
gain stage 60 and has a distal portion 118 which includes the third
gain stage 62.
[0077] In one implementation of the second expression of the
embodiment of FIGS. 2-13, the medical ultrasound handpiece 28
includes a housing 120 (also called a mid housing), wherein the
housing 120 surrounds the transducer assembly 30'. In one
variation, the medical ultrasound handpiece 28 includes an annular
bumper assembly 122 having a plurality of spaced apart and inwardly
projecting bumpers 124. The bumper assembly 122 surrounds the first
stacked plurality 40 of piezoelectric transducer disks 42, wherein
the bumpers 124 are in contact with the first stacked plurality 40
of piezoelectric transducer disks 42 proximate the first node 36,
and the housing 120 is in surrounding contact with the bumper
assembly 122.
[0078] In one arrangement of the second expression of the
embodiment of FIGS. 2-13, the transducer assembly 30' has a
longitudinal axis 126, the housing 120 has a multi-lug inward
flange 128, and the horn-mount component 104 has a multi-lug
outward flange 130 disposed proximate the third node 58 (and distal
the multi-lug inward flange 128 after first aligning the lugs for
passage and then relatively rotating for non-passage). In this
arrangement, the handpiece 28 includes a nose cone assembly 132
having a dielectric multi-lug ring 134 (such as, but not limited
to, a compressed, soft elastomeric, vibration isolating, multi-lug
ring) disposed longitudinally between (after first aligning the
lugs for passage and then relatively rotating for non-passage) and
in contact with the multi-lug inward and outward flanges 128 and
130 and covering and contacting the multi-lug outward flange 130.
In this arrangement, the housing 120 is in surrounding contact with
the multi-lug ring 134.
[0079] In one example, the nose cone assembly 132 includes a
longitudinally-compressed dielectric washer 136 (such as, but not
limited to, an elastomeric washer) distally abutting the multi-lug
outward flange 130 and includes an annular nose cone 138 distally
abutting the washer 136. In this example, the housing 120 is in
surrounding contact with the nose cone 138. In one variation, the
nose cone assembly 132 includes first and second O-ring seals 140
and 142 as shown in FIGS. 3 and 9. In one modification, the nose
cone assembly 132 includes inner and outer conductive (electrically
conductive) rings 144 and 146 separated by an annular dielectric
member 148 as shown in FIG. 9.
[0080] In the same example, the outer conductive ring 146 contacts
the housing 120 and is a ground (electrical ground) ring, and the
inner conductive ring 144 is a hot (electrically hot) ring
electrically connectable (in part by wiring 150) to a low AC output
of an ultrasound electric generator (not shown). The instrument 76
has a switch (not shown) which is electrically connected to the
inner and outer conductive rings 144 and 146 when the instrument 76
is attached to the stud 74. The switch controls the ultrasound
electric generator. In other arrangements, not shown, the inner and
outer conductive rings 144 and 146 are omitted, and the ultrasound
electric generator has an onboard switch or the handpiece has a
switch.
[0081] In the same example, the generator has positive and negative
high AC outputs electrically connectable (in part by wiring 152 and
jumpers 154) to electrodes 156 disposed between adjacent
piezoelectric transducer disks 42. The piezoelectric transducer
disks 42 of the first stacked plurality 40 of piezoelectric
transducer disks 42 are radially-inwardly electrically isolated
from the transducer-horn component 102 by a first dielectric
cylinder 158. The piezoelectric transducer disks 42 of the second
stacked plurality 44 of piezoelectric transducer disks 42 are
radially-inwardly electrically isolated from the transducer-horn
component 102 by a second dielectric cylinder 160. It is noted that
the stud 74 extends distally of the nose cone assembly 132, and
that a proximal end portion of the nose cone 138 is disposed
inside, and press fitted to, a distal end portion of the housing
120.
[0082] In the same example, the bumper assembly 122 includes pins
162 from which the wiring 152 extends to the electrodes/jumpers
156/154 to power the piezoelectric transducer disks 42. In one
variation, the handpiece 28 includes an annular end cap 164 having
pins (not shown) which engage the pins 162 of the bumper assembly
122 when a distal end portion of the end cap 164 is disposed
outside, and press fitted to, a proximal end portion of the housing
120. This causes the bumper assembly 122 to be longitudinally
secured between an inner annular seat (not shown) of the housing
120 and an inner annular seat (not shown) of the end cap 164.
[0083] In the same example, the handpiece 28 includes a cable 166
containing the wiring 150 and the wiring 152. The cable 166 extends
from a proximal end portion of the end cap 164 to a proximal plug
168. The plug 168 is electrically connectable to an ultrasound
electric generator (not shown).
[0084] A third embodiment of the invention is shown in FIG. 15. A
first expression of the embodiment of FIG. 15 is for a medical
ultrasound handpiece 210 including a 1-wave medical ultrasound
transducer assembly 212. The transducer assembly 212 includes
consecutive first and distal-most second half-wave sections 214 and
216, wherein the first half-wave section 214 includes a first node
218 and the second half-wave section 216 includes a second node
220. The first half-wave section 214 includes a first stacked
plurality 222 of piezoelectric transducer disks 224 and the second
half-wave section 216 includes a second stacked plurality 226 of
piezoelectric transducer disks 224. The transducer assembly 212
includes first and second gain stages 228 and 230, wherein the
first gain stage 228 is located in the first half-wave section 214
distal the first stacked plurality 222 of piezoelectric transducer
disks 224, and wherein the second gain stage 230 is located in the
second half-wave section 216 distal the second stacked plurality
226 of piezoelectric transducer disks 224.
[0085] In one enablement of the first expression of the embodiment
of FIG. 15, the second half-wave section 216 distally terminates in
a stud 232 which is attachable to an ultrasonically-vibratable
medical-treatment instrument 234. In one variation, the stud 232
includes a proximal threaded portion 242 and includes a distal
non-threaded portion 244 adjoining the proximal threaded portion
242, wherein the proximal threaded portion 242 is threadably
attachable to the instrument 234. Examples of non-stud and/or
non-threadable attachments are left to those skilled in the art. A
method for tuning the handpiece 210 is identical to the previously
described method for tuning the handpiece 28.
[0086] In one arrangement of the first expression of the embodiment
of FIG. 15, the first stacked plurality 222 of piezoelectric
transducer disks 224 is substantially centered about the first node
218, and the second stacked plurality 226 of piezoelectric
transducer disks 224 is disposed proximal the second node 220. In
one variation, the first gain stage 228 has a proximal end 236
which is distally spaced apart from the first stacked plurality 222
of piezoelectric transducer disks 224 and has a distal end 238
which is disposed proximate a common antinode 240 of the first and
second half-wave sections 214 and 216. In one example, the first
gain stage 228 includes a stacked plurality 246 of piezoelectric
transducer disks 224'. In another example, not shown, the first
gain stage lacks any piezoelectric transducer disks. It is noted
that an operating handpiece 210 will have a proximal antinode at
the proximal end of the transducer assembly 212 and a distal
antinode at the distal end of the transducer assembly 212.
[0087] A fourth embodiment of the invention is shown in FIG. 16. A
first expression of the embodiment of FIG. 16 is for a medical
ultrasound handpiece 310 including a 1/2-wave medical ultrasound
transducer assembly 312. The transducer assembly 312 includes a
proximal antinode 314, a distal antinode 316, and a node 318
located between the proximal and distal antinodes 314 and 316. The
transducer assembly 312 includes a first stacked plurality 320 of
piezoelectric transducer disks 322 located proximal the node 318, a
second stacked plurality 324 of piezoelectric transducer disks 322'
located distal the node 318, and a gain stage 326 located distal
the second stacked plurality 324 of piezoelectric transducer disks
322'.
[0088] In one enablement of the first expression of the embodiment
of FIG. 16, the transducer assembly 312 distally terminates in a
stud 328 which is attachable to an ultrasonically-vibratable
medical-treatment instrument 330. In one variation, the stud 328
includes a proximal threaded portion 332 and includes a distal
non-threaded portion 334 adjoining the proximal threaded portion
332, wherein the proximal threaded portion 332 is threadably
attachable to the instrument 330. Examples of non-stud and/or
non-threadable attachments are left to those skilled in the art. A
method for tuning the handpiece 310 is identical to the previously
described method for tuning the handpiece 28.
[0089] A fifth embodiment of the invention is shown in FIG. 17. A
first expression of the embodiment of FIG. 17 is for a medical
ultrasound system 410 including a medical ultrasound transducer
assembly 412 and an ultrasonically-vibratable medical-treatment
instrument 414. The transducer assembly 412 has a gain of unity and
has a distal end portion 418. The instrument 414 is attachable (and
in one example is attached) to the distal end portion 418 of the
transducer assembly 412 and has at least one gain stage 420, 422,
424 and 426.
[0090] In one enablement of the first expression of the embodiment
of FIG. 17, the at-least-one gain stage 420, 422, 424 and 426
includes a plurality of gain stages 420, 422, 424 and 426. In one
variation, each gain stage 420, 422, 424 and 426 has a proximal end
428 disposed proximate a corresponding node 430 of the instrument
414 and has a distal end 432 disposed proximate a corresponding
antinode 434 of the instrument to maximize the displacement at the
distal end 436 of the instrument 414. In one implementation of the
embodiment of FIG. 17, the transducer assembly 412 includes a
stacked plurality 438 of piezoelectric transducer disks 440. In one
example, the (unity gain) transducer assembly 412 should have less
quiescent power and heat than a high gain transducer assembly and
should provide for better sealing (because of less nodal vibration)
than a high gain transducer assembly. In the same or a different
example, the (unity gain) transducer assembly 412 should provide
for a smaller handpiece 412 and should provide the potential for
quick connection of an instrument 414 (such as a scalpel) to the
handpiece 412.
[0091] A sixth embodiment of the invention is shown in FIG. 18. A
first expression of the embodiment of FIG. 16 is for a medical
ultrasound system 442 including a medical ultrasound transducer
assembly 444 and an ultrasonically-vibratable medical-treatment
instrument 446. The transducer assembly 444 has a distal end
portion 450. The instrument 446 is attachable (and in one example
is attached) to the distal end portion 450 of the transducer
assembly 444. The transducer assembly 444 and the attached
instrument 446 together have an operating wavelength. The
transducer assembly 444 alone has a length which is at least equal
to 1/4 of the operating wavelength and which is less than 1/2 of
the operating wavelength. The transducer assembly 444 and the
attached instrument 446 together have a length equal to N times 1/2
of the operating wavelength, wherein N is a non-zero positive whole
number.
[0092] In one enablement of the first expression of the embodiment
of FIG. 18, N equals one. In one variation, the transducer assembly
444 and the attached instrument 446 together have a node 452, and
the transducer assembly 444 includes the node 452. In one
modification, the transducer assembly 444 includes a stacked
plurality 454 of piezoelectric transducer disks 456. In one
example, the transducer assembly 444 includes a flange 458 disposed
proximate the node 452. In a first construction, the flange 458 is
disposed proximal the node 452 with the instrument 446 attached to
the flange 458 and with the stacked plurality 454 of piezoelectric
transducer disks 456 disposed proximal and abutting the flange
458.
[0093] In a second construction, as shown in alternate embodiment
of FIG. 19, the flange 460 of the transducer assembly 462 is
disposed distal the node 464 with the instrument 466 attached to
the flange 460 and with the stacked plurality 468 of piezoelectric
transducer disks 470 disposed proximal and abutting the flange 460.
In a third construction, as shown in the alternate embodiment of
FIG. 20, the flange 472 of the transducer assembly 474 is
substantially centered at the node 476 with the instrument 478
attached to the flange 472, with the stacked plurality 480 of
piezoelectric transducer disks 482 disposed proximal and abutting
the flange 472, and with an additional stacked plurality 484 of
piezoelectric transducer disks 482 disposed distal and abutting the
flange 472.
[0094] A seventh embodiment of the invention is shown in FIG. 21. A
first expression of the embodiment of FIG. 21 is for a medical
ultrasound handpiece 510 including a medical ultrasound transducer
assembly 512. The transducer assembly 512 has proximal and distal
nodes 514 and 516. The transducer assembly 512 has a first
transducer-assembly-to-housing mounting feature 518 disposed
proximate the proximal node 514 and a second
transducer-assembly-to-housing mounting feature 520 disposed
proximate the distal node 516. The transducer assembly 512 lacks
any additional transducer-assembly-to-housing mounting feature.
[0095] In one enablement of the first expression of the embodiment
of FIG. 21, the handpiece 510 includes a housing 522 having an
opening 524 and surrounding the transducer assembly 512, wherein
the transducer assembly 512 is insertable into the housing 522
through the opening 524. In one variation, the transducer assembly
512 includes a stacked plurality 526 of piezoelectric transducer
disks 528. In a first example, the first
transducer-assembly-to-housing mounting feature 518 is a first
outward flange of the transducer assembly 512, and the second
transducer-assembly-to-housing mounting feature 520 is second
outward flange of the transducer assembly 512, wherein the first
outward flange projects more (or less) than the second outward
flange.
[0096] In a second example, as shown in the alternate embodiment of
FIG. 22, the first transducer-assembly-to-housing mounting feature
530 is an outward flange of the transducer assembly 532, and the
second transducer-assembly-to-housing mounting feature 534 is an
O-ring groove of the transducer assembly 532. The outward flange
projects more (or less) than an O-ring (not shown) disposed in the
O-ring groove.
[0097] In a third example, as shown in the alternate embodiment of
FIG. 23, the first transducer-assembly-to-housing mounting feature
536 is an O-ring groove of the transducer assembly 538, and the
second transducer-assembly-to-housing mounting feature 540 is an
outward flange of the transducer assembly 538. An O-ring (not
shown) disposed in the O-ring groove projects more (or less) than
the outward flange.
[0098] In a fourth example, as shown in the alternate embodiment of
FIG. 24, the first transducer-assembly-to-housing mounting feature
542 is a first O-ring groove of the transducer assembly 544, and
the second transducer-assembly-to-housing mounting feature 546 is
second O-ring groove of the transducer assembly 544. A first O-ring
(not shown) disposed in the first O-ring groove projects more (or
less) than a second O-ring (not shown) disposed in the second
O-ring groove.
[0099] In a fifth example, as shown in the alternate embodiment of
FIG. 25, the first transducer-assembly-to-housing mounting feature
548 is a first pair of O-ring-bounding outward flanges of the
transducer assembly 550,. and the second
transducer-assembly-to-housing mounting feature 552 is a second
pair of O-ring-bounding outward flanges of the transducer assembly
550. A first O-ring (not shown) bounded by the first pair of
O-ring-bounding outward flanges projects more (or less) than a
second O-ring (not shown) bounded by the second pair of
O-ring-bounding outward flanges.
[0100] An eighth embodiment of the invention is shown in FIGS.
26-29. A first expression of the embodiment of FIGS. 26-29 is for a
medical ultrasound handpiece 610 including a medical ultrasound
transducer assembly 612 and an annular connector assembly 614
(which is also called an annular bumper assembly). The transducer
assembly 612 includes a metallic end-mass component 616, a
piezoelectric transducer disk 618, and an electrode 620. The
piezoelectric transducer disk 618 is located distal the end-mass
component 616 and is in electrical contact with the electrode 620.
The connector assembly 614 surrounds the transducer assembly 612,
is in electrical contact (such as at least in part by wiring 623)
with the electrode 620, and is electrically connectable to an
ultrasound electric generator 622.
[0101] In one enablement of the first expression of the embodiment
of FIGS. 26-29, the medical ultrasound handpiece 610 includes an
electric cable 624 and a cable socket 626, wherein the cable 624
has a proximal end 628 electrically connectable to the ultrasound
electric generator 622 and has a distal end 630 electrically
connected to the cable socket 626, and wherein the end-mass
component 616 is disposable within the cable socket 626. In one
variation, the cable socket 626 has connector pins 632, and the
connector assembly 614 has connector pins 634 which are engagable
with the connector pins 632 of the cable socket 626. In one
modification, the handpiece 610 includes an end cap 636, wherein
the cable socket 626 is disposable in the end cap 636. In one
example, the handpiece 610 includes a housing 638, wherein the
housing 638 surrounds the connector assembly 614 and has a proximal
end portion 640, and wherein the end cap 636 has a distal end
portion 642 which is press-fittingly attachable to the proximal end
portion 640 of the housing 638.
[0102] A second expression of the embodiment of FIGS. 26-29 is for
a medical ultrasound handpiece 610 including a medical ultrasound
transducer assembly 612 and an annular connector assembly 614. The
transducer assembly 612 includes a metallic end-mass component 616,
a stacked plurality 644 of piezoelectric transducer disks 618, and
electrodes 620. The stacked plurality 644 of piezoelectric
transducer disks 618 is located distal the end-mass component 616.
Each piezoelectric transducer disk 618 is in electrical contact
with a corresponding electrode 620. The connector assembly 614
surrounds the transducer assembly 612, is in electrical contact
(such as at least in part by wiring 623) with the electrodes 620,
and is electrically connected to a cable socket 626 which is
electrically connectable to an ultrasound electric generator
622.
[0103] It is noted that in FIG. 27, the left-most of the two shown
piezoelectric transducer disks 618 is in electrical contact with
the left-most (but not the right-most) of the two shown electrodes
620 and the right-most of the two shown piezoelectric transducer
disks 618 is in electrical contact with the right-most (but not the
left-most) of the two shown electrodes 620.
[0104] In one enablement of the second expression of the embodiment
of FIGS. 26-29, the medical ultrasound handpiece 610 includes an
electric cable 624, wherein the cable 624 has a proximal end 628
electrically connectable to the generator 622 and has a distal end
630 electrically connected to the cable socket 626, and wherein the
end-mass component 616 is disposed within the cable socket 626. In
one variation, the cable socket 626 has connector pins 632, and the
connector assembly 614 has connector pins 634 which are engaged
with the connector pins 632 of the cable socket 626. In one
modification, the handpiece 610 includes an end cap 636, wherein
the cable socket 626 is disposed in the end cap 636. In one
example, the handpiece 610 includes a housing 638, wherein the
housing 638 surrounds the connector assembly 614 and has a proximal
end portion 640, and wherein the end cap 636 has a distal end
portion 642 which is press-fittingly attached to the proximal end
portion 640 of the housing 638.
[0105] A ninth embodiment of the invention is shown in FIGS. 30-32.
A first expression of the embodiment of FIGS. 30-32 is for a
medical ultrasound handpiece 710 including a medical ultrasound
transducer assembly 712, an inner conductive ring 714, and an outer
conductive ring 716. The transducer assembly 712 is electrically
connectable to an ultrasound electric generator 718, has a
longitudinal axis 720, and is attachable to an
ultrasonically-vibratable medical-treatment instrument 722 having a
switch 744 which has an open position and a closed position. The
inner conductive ring 714 is substantially coaxially aligned with
the longitudinal axis 720, surrounds the transducer assembly 712,
and has a distally-facing first annular surface 746. The outer
conductive ring 716 is substantially coaxially aligned with the
longitudinal axis 720, surrounds the transducer assembly 712, and
has a distally-facing second annular surface 748. The outer
conductive ring 716 is electrically isolated from the inner
conductive ring 714. The first and second annular surfaces 746 and
748 are in electric contact with the switch 744 of the attached
instrument 722 when the switch 744 is in the closed position. The
inner and outer conductive rings 714 and 716 are electrically
connectable to the generator 718, and the switch 744 of the
attached instrument 722 controls the connected generator 718.
[0106] In one enablement of the first expression of the embodiment
of FIGS. 30-32, the transducer assembly 712 is attached to the
instrument 722. In one variation, the transducer assembly 712
distally terminates in a stud 750 which is attachable to the
instrument 722. In one modification, the stud 750 is threadably
attachable to the instrument 722.
[0107] In one implementation of the first expression of the
embodiment of FIGS. 30-32, the handpiece 710 includes an annular
dielectric member 758, wherein the inner and outer conductive rings
714 and 716 are separated by the dielectric member 758. In one the
inner and outer conductive rings 714 and 716 are electrically
connected to the generator 718. In one variation, an electric cable
752 extends from the handpiece 710 to a proximal plug 754 which is
attachable to the generator 718, and wiring 756 extends from the
cable 752 within the handpiece 710 to the transducer assembly 712,
to the inner conductive ring 714, and to the outer conductive ring
716. In an alternate variation, not shown, wiring does not extend
directly from the cable to the outer conductive ring but extends to
the housing which electrically contacts the outer conductive ring,
wherein the housing serves as electrical ground. In one example,
the transducer assembly 712 is attached to the instrument 722.
[0108] In one construction of the first expression of the
embodiment of FIGS. 30-32, closing the switch 744 causes a first
switch pin 760 to electrically contact the inner conductive ring
714 and causes a second switch pin 762 to electrically contact the
outer conductive ring 716. In the same or a different construction,
the handpiece 710 includes a housing 764 and a nose cone assembly
766, wherein the nose cone assembly 766 is attached to the housing
764 and includes the inner conductive ring 714, the outer
conductive ring 716, and the dielectric member 758. In one
modification, mounts 768 disposed at nodes of the transducer
assembly 712 secure the transducer assembly 712 within and to the
housing 764, wherein the mounts 768 have openings to pass the
wiring 756 from the cable 752 to the inner and outer conductive
rings 714 and 716.
[0109] In one application of the first expression of the embodiment
of FIGS. 30-32, the instrument 722 has an ultrasonically vibratable
portion 770 which is attachable to the stud 750 and has a
surrounding non-vibratable portion 772. The non-vibratable portion
772 surrounds the vibratable portion 770 and includes the switch
744. In one variation, the switch 744 is a two button switch (such
as that described in US Patent Application Publications
2004/0147947 and 2002/0057541). In another variation, not shown,
the switch is a one button switch. Other designs of the switch and
modes of generator control by the switch, are left to those skilled
in the art.
[0110] A tenth embodiment of the invention is shown in FIGS. 33-35.
A first expression of the embodiment of FIGS. 33-35 is for a
medical ultrasound handpiece 810 including a medical ultrasound
transducer assembly 812, a housing 814, a mount 816, and an annular
bumper unit 818. The housing 814 surrounds the transducer assembly
812. The mount 816 pivotally attaches the transducer assembly 812
to the housing 814. The bumper unit 818 is attached to the housing
814 and includes a plurality of spaced apart and inwardly
projecting bumpers 820. None of the bumpers 820 is in contact with
the transducer assembly 812 when the transducer assembly 812 is not
under a pivoting load (as shown in FIG. 34). At least one of the
bumpers 820 is contact with the transducer assembly 812 when the
transducer assembly 812 is under the pivoting load (as shown in
FIG. 35).
[0111] A pivoting load is a load which causes the transducer
assembly 812 to pivot about the mount 816 with respect to the
housing 814. In one application, the transducer assembly 812
distally terminates in a stud 822, and an ultrasonically-vibratable
medical-treatment instrument (not shown) is attachable to the stud
822. In one example, a pivoting load is produced when a surgeon
holds the housing 814 and presses down on patient tissue with the
distal end of the attached instrument which causes a the transducer
assembly 812 to pivot about the mount 816 with respect to the
housing 814 and causes the transducer assembly 812 proximal the
mount 816 to contact at least one of the bumpers 820 as shown in
FIG. 35. It is noted that a small area of contact of the transducer
assembly 812 with the bumpers 820 should reduce damping and power
loss.
[0112] In one construction of the first expression of the
embodiment of FIGS. 33-35, the mount 816 includes an elastomeric
ring. Other constructions and types of mounts are left to the
artisan.
[0113] In one enablement of the first expression of the embodiment
of FIGS. 33-35, the transducer assembly 812 has a distal-most node
826, and the mount 816 is in contact with the transducer assembly
812 proximate the distal-most node 826. In one variation, the
transducer assembly 812 has a proximal-most node 828, and the
bumper unit 818 is disposed proximate the proximal-most node 828.
In one example, the bumper unit 818 is press-fittingly attached to
the housing 814. In one illustration, the transducer assembly 812
is a 11/2 wave transducer assembly.
[0114] An eleventh embodiment of the invention is shown in FIGS.
36-42. A first expression of the embodiment of FIGS. 36-42 is for a
medical ultrasound handpiece 910 including a medical ultrasound
transducer assembly 912, at least one mounting member 914, and a
first housing component 916. The transducer assembly 912 has a
longitudinal axis 918 and has a substantially coaxially aligned,
circumferential surface groove 920. The at-least-one mounting
member 914 is at-least-partially-annular and has an inner portion
922 located in the surface groove 920. The first housing component
916 surrounds the transducer assembly 912 and has a distal end
portion 924 including an annular longitudinally-facing surface 926
with a recessed seat 928. The at-least-one mounting member 914 has
at least a proximal portion 930 located in the seat 928.
[0115] In a first construction of the first expression of the
embodiment of FIGS. 36-42, the at-least-one mounting member 914 is
a partially annular monolithic mounting member. In a second
construction, not shown, the at-least-one mounting member includes
a plurality (such as two) mounting members disposed in a partially
annular array. In one choice of materials, the at-least-one
mounting member 914 is dielectric (or at least the inner portion
922 is dielectric or coated with a dielectric material) to
electrically isolate the distal end portion 924 of the first
housing component 916 from the surface groove 920 of the transducer
assembly 912. In one example, the at-least-one mounting member 914
is elastomeric. In one employment, the gap, when the at-least-one
mounting member 914 has a partially-annular construction, allows
for the passage of wiring (not shown). Other constructions,
including fully annular constructions, are left to the artisan.
[0116] In one enablement of the first expression of the embodiment
of FIGS. 36-42, the handpiece 910 includes a second housing
component 932 surrounding the transducer assembly 912 and having a
proximal end portion 934 which surrounds and is attached to the
distal end portion 924 of the first housing component 916. In one
variation, the proximal end portion 934 of the second housing
component 932 includes an internal annular ledge 936 which seats
against a distal portion 938 of the at-least-one mounting member
914. In one variation, the proximal end portion 934 of the second
housing component 932 is press-fittingly attached to the distal end
portion 924 of the first housing component 916. In one example, the
transducer assembly 912 has a distal-most node 940, and the surface
groove 920 is disposed proximate the distal-most node 940.
[0117] In one employment of the first expression of the embodiment
of FIGS. 36-42, the first housing component 916 is referred to as
the housing and the second housing component 932 is referred to as
the nose cone. It is noted that in schematic FIG. 37, the
transducer assembly 912 is shown with jumpers 942, wherein jumpers
have been discussed in one or more previous embodiments.
[0118] In a first method of assembly of the handpiece 910, the
proximal end (the left end in FIG. 37) of the transducer assembly
912 is not conventionally inserted into the distal end opening (the
right end opening in FIG. 37) of the first housing component 916
wherein the protruding jumpers 942 and wiring (not shown) at the
stacked plurality or (stacked pluralities) of piezoelectric
transducer disks (not shown) of the transducer assembly 912 have to
be fished through the narrow distal end opening. Rather, by making
the at-least-one mounting member 914 be a separate piece (or
separate pieces) from the transducer assembly 912 and act as a
conventional transducer assembly mounting flange, the distal end
(the right end in FIG. 37) of the transducer assembly 912 is
inserted in the proximal end opening (the left end opening in FIG.
37) of the first housing component 916, and pushed to the position
shown in FIG. 38 exposing the surface groove 920 of the transducer
assembly 912 beyond the distal end (the right end in FIG. 38) of
the first housing component 916.
[0119] Continuing with the assembly, then the at least-one-mounting
member 914 is installed in the surface groove 920 as shown in FIG.
39. Then, the transducer assembly 912 is moved proximally within
the first housing component 916 to seat the proximal portion 930 of
the at least-one-mounting member 914 within the recessed seat 928
of the longitudinally-facing surface 926 of the distal end portion
924 of the first housing component 916 as shown in FIG. 40. Then,
the proximal end portion 934 of the second housing component 932 is
press fittingly attached to the distal end portion 924 of the first
housing component 916 as shown in FIG. 36.
[0120] In one arrangement of the first expression of the embodiment
of FIGS. 36-42, the at-least-one mounting member 914 has at least
one peripheral flat 944 which engages a corresponding at least one
peripheral flat 946 on the recessed seat 928 of the
longitudinally-facing surface 926 of the distal end portion 924 of
the first housing component 916. This prevents rotation of the
at-least-one mounting member 914. In the same or a different
arrangement, the at-least-one mounting member 914 is flexible
(i.e., can be flexed by an adult person of average strength) to
facilitate installation.
[0121] Several benefits and advantages are obtained from one or
more of the expressions of embodiments of the invention. In one
example, one or more or all of the expressions of embodiments of
the invention help enable a relatively small size medical
ultrasound transducer assembly to provide an attached
ultrasonically-vibratable medical-treatment instrument with a
desirable high displacement (i.e., a large vibrational amplitude)
resulting in a relatively small size handpiece which is suitable
for a surgeon to hold and use in precise and delicate surgery.
[0122] While the present invention has been illustrated by a
description of several expressions, embodiments, and examples, etc.
thereof, it is not the intention of the applicants to restrict or
limit the spirit and scope of the appended claims to such detail.
Numerous other variations, changes, and substitutions will occur to
those skilled in the art without departing from the scope of the
invention. It will be understood that the foregoing description is
provided by way of example, and that other modifications may occur
to those skilled in the art without departing from the scope and
spirit of the appended Claims.
* * * * *