U.S. patent application number 13/043022 was filed with the patent office on 2011-09-08 for method for using microelectromechanical systems to generate movement in a phacoemulsification handpiece.
This patent application is currently assigned to Abbott Medical Optics Inc.. Invention is credited to Timothy Hunter.
Application Number | 20110218483 13/043022 |
Document ID | / |
Family ID | 44144731 |
Filed Date | 2011-09-08 |
United States Patent
Application |
20110218483 |
Kind Code |
A1 |
Hunter; Timothy |
September 8, 2011 |
METHOD FOR USING MICROELECTROMECHANICAL SYSTEMS TO GENERATE
MOVEMENT IN A PHACOEMULSIFICATION HANDPIECE
Abstract
The present invention relates to a phacoemulsification
handpiece, comprising a needle and a microelectromechanical system
(MEMS) device, wherein the needle is coupled with the MEMS device.
The phacoemulsification handpiece may further comprise a horn,
wherein the horn is coupled with the needle and the MEMS device.
The MEMS device is capable of generating movement of the needle in
at least one direction, wherein at least one direction is selected
from the group consisting of transversal, torsional, and
longitudinal. The present invention also relates to a method of
generating movement, comprising providing a phacoemulsification
handpiece, wherein the handpiece comprises a needle and one or more
MEMS devices; applying a voltage or current to the one or more MEMS
devices, wherein the MEMS devices are coupled with the needle; and
moving the needle in at least one direction. The present invention
also relates to a vitrectomy cutter comprising one or more MEMS
devices.
Inventors: |
Hunter; Timothy; (Irvine,
CA) |
Assignee: |
Abbott Medical Optics Inc.
Santa Ana
CA
|
Family ID: |
44144731 |
Appl. No.: |
13/043022 |
Filed: |
March 8, 2011 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61311695 |
Mar 8, 2010 |
|
|
|
Current U.S.
Class: |
604/22 |
Current CPC
Class: |
A61F 9/00745 20130101;
A61F 9/00763 20130101 |
Class at
Publication: |
604/22 |
International
Class: |
A61F 9/007 20060101
A61F009/007 |
Claims
1. A phacoemulsification handpiece, comprising: a needle; and
multiple microelectromechanical system devices, wherein the needle
is coupled with the microelectromechanical system devices.
2. The phacoemulsification handpiece of claim 1, further comprising
a horn, wherein in the horn is coupled with the needle and the
microelectromechanical system devices.
3. The phacoemulsification handpiece of claim 1, wherein the
microelectromechanical system devices are capable of generating
movement of the needle in at least one direction.
4. The phacoemulsification handpiece of claim 3, wherein at least
one direction is selected from the group consisting of transversal,
torsional, and longitudinal along a longitudinal axis of the
needle.
5. The phacoemulsification handpiece of claim 1, further comprising
a pad and a linkage, wherein the pad is coupled with the
microelectromechanical system devices via the linkage and the pad
is coupled with the needle.
6. The phacoemulsification handpiece of claim 5, wherein the pad is
coupled with the needle via a linkage.
7. The phacoemulsification handpiece of claim 1, wherein the
microelectromechanical system devices are coupled with an outer
surface of the needle.
8. A method of generating movement, comprising: providing a
phacoemulsification handpiece, wherein the handpiece comprises a
needle and one or more microelectromechanical system devices;
applying a voltage or current to the one or more
microelectromechanical system devices, wherein the
microelectromechanical system devices are coupled with the needle;
and moving the needle in at least one direction.
9. The method of claim 8, wherein the at least one direction is
selected from the group consisting of transversal, torsional, and
longitudinal along a longitudinal axis of the needle.
10. A vitrectomy cutter, comprising: a needle body having one or
more ports; a blade, wherein the blade is located within the needle
body and capable of passing over the one or more ports; and a
microelectromechanical system device, wherein the
microelectromechanical device is coupled with the blade; wherein
the microelectromechanical system device is capable of oscillating
the blade.
11. The vitrectomy cutter of claim 10, wherein the
microelectromechanical system is coupled with the blade via a
linkage.
Description
CLAIM OF PRIORITY
[0001] The present application claims priority under 35 U.S.C.
.sctn.119(e) to provisional application No. 61/311,695, filed on
Mar. 8, 2010 under the same title, which is incorporated herein by
reference in its entirety. Full Paris Convention priority is hereby
expressly reserved.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to an ultrasound handpiece and
in particular, generating movement of a tip of the handpiece using
micro electromechanical systems (MEMS).
BACKGROUND OF THE INVENTION
[0003] During a phacoemulsification ("phaco") procedure, a needle
of an ultrasound handpiece is placed within the capsular bag of an
eye to emulsify the cataractic lens. The emulsified lens is removed
from the eye and an intraocular lens ("IOL") is implanted.
Ultrasound handpieces are driven by piezoelectric crystals or
magnetostrictive drivers. Energy is applied to the piezoelectric
crystals to vibrate the crystals to generate ultrasound energy,
which is then transmitted through the needle of the handpiece into
the cataractic lens. There are several theories as to how the
cataractic lens is emulsified. One school of thought is that the
ultrasound vibration causes cavitation, which in turn emulsifies
the lens. Another school of thought is that the lens is emulsified
by mere mechanical breakdown. Also, another school of thought is
that it is a combination of cavitation and mechanical breakdown
that emulsifies the cataractic lens. Despite these theories, there
are several limitation placed on ultrasound handpieces when
employing piezoelectric crystals. First, before each use the
handpiece must be tuned, thereby lengthening the time of the
procedure. Second, handpieces comprising piezoelectric crystals
generate significant heat during use that may cause tissue damage.
Third, the crystals add a significant amount of weight to the
handpieces making them heavy and cumbersome to use and can cause
fatigue for the doctors using such handpieces.
[0004] Based upon the foregoing, it would be advantageous to have a
handpiece that is lighter, does not require tuning prior to use,
and does not generate tissue damaging heat.
SUMMARY OF THE INVENTION
[0005] The present invention relates to a phaco handpiece,
comprising a needle and a MEMS device, wherein the needle is
coupled with the MEMS device. The phaco handpiece may further
comprise a horn, wherein the horn is coupled with the needle and
the MEMS device. The MEMS device is capable of generating movement
of the needle in at least one direction, wherein at least one
direction is selected from the group consisting of transversal,
torsional, and longitudinal along a longitudinal axis of the
needle. The phaco handpiece may further comprise a pad and a
linkage, wherein the pad is coupled with the MEMS device via the
linkage and the pad is coupled with the needle. The pad may be
coupled with the needle via a linkage. The MEMS device may also be
coupled with an outer surface of the needle.
[0006] The present invention also pertains to a method of
generating movement, comprising providing a phaco handpiece,
wherein the handpiece comprises a needle and one or more MEMS
devices; applying a voltage or current to the one or more MEMS
devices, wherein the MEMS devices are coupled with the needle; and
moving the needle in at least one direction. The at least one
direction may be selected from the group consisting of transversal,
torsional, and longitudinal along a longitudinal axis of the
needle.
[0007] The present invention also pertains to a vitrectomy cutter,
comprising a needle body having one or more ports; a blade, wherein
the blade is located within the needle body and capable of passing
over the one or more ports; and a microelectromechanical system
device, wherein the microelectromechanical device is coupled with
the blade; wherein the microelectromechanical system device is
capable of oscillating the blade.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention is best understood with reference to
the following detailed description of the invention and the
drawings in which:
[0009] FIG. 1 is a cross-sectional view of an ultrasound phaco
handpiece;
[0010] FIG. 2 is a plan view of an embodiment of a MEMS system;
[0011] FIG. 3 is a plan view of an embodiment of a MEMS system;
[0012] FIG. 4 is a bottom view of an embodiment of a MEMS
system;
[0013] FIG. 5 is a side view of an embodiment of a MEMS system;
[0014] FIG. 6 is a plan view of an embodiment of a MEMS system;
[0015] FIG. 7 is a plan view of a vitrectomy cutter; and
[0016] FIG. 8 is a plan view of an embodiment of a MEMS system.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Reference will now be made in detail to embodiments of the
invention, examples of which are illustrated in the accompanying
drawings. While the invention will be described in conjunction with
the embodiments, it will be understood that they are not intended
to limit the invention to those embodiments. On the contrary, the
invention is intended to cover alternatives, modifications, and
equivalents, which may be included within the spirit and scope of
the invention as defined by the appended claims.
[0018] In FIG. 1 a cross-section along the longitudinal axis of a
portion of an ultrasound phaco handpiece 100 known in the art is
shown. Generally, handpiece 100 includes a needle 110, defining a
lumen that is operatively coupled with an aspiration pump (not
shown), forming an aspiration line 114. The proximal end of needle
110 is coupled with horn 150, which has its proximal end coupled
with a set of piezoelectric crystals 180, shown as three rings.
Horn 150, crystals 180, and a proximal portion of the needle 110
are enclosed within handpiece casing 170 having an irrigation port
coupled with an irrigation line 190 defining an irrigation pathway
195. Irrigation line 190 is coupled with an irrigation source (not
shown). Horn 150 is typically an integrated metal, such as
titanium, structure and often includes a rubber O ring 160 around
the mid-section, just before horn 150 tapers to fit with needle 110
at the distal end of horn 150. O ring 160 snugly fits between horn
150 and casing 170. O ring 160 seals the proximal portion of horn
150 from irrigation pathway 195. Thus, there is a channel of air
defined between horn 150 and the casing 170. Descriptions of
handpieces known in the art are provided in U.S. Pat. No. 6,852,092
(Kadziauskas, et al.) and U.S. Pat. No. 5,843,109 (Mehta, et al.),
which are hereby incorporated by reference in their entirety.
[0019] In preparation for operation, sleeve 120 is typically added
to the distal end of handpiece 100, covering the proximal portion
of the needle 110 (thus, exposing the distal tip of the needle),
and the distal end of irrigation pathway 195, thereby extending
pathway 195 and defining an irrigation port 122 just before the
distal tip of needle 110. Needle 110 and a portion of sleeve 120
are then inserted through the cornea of the eye to reach the
cataractic lens.
[0020] During operation, irrigation path 195, the eye's chamber and
aspiration line 114 form a fluidic circuit, where irrigation fluid
enters the eye's chamber via irrigation path 195, and is then
aspirated through aspiration line 114 along with other materials
that the surgeon desires to aspirate out, such as the cataractic
lens. If, however, the materials, such as the cataractic lens, are
too hard and massive to be aspirated through the aspiration line
114, then the distal end of the needle 110 is ultrasonically
vibrated and applied to the material to be emulsified into a size
and state that can be successfully aspirated.
[0021] Needle 110 is ultrasonically vibrated by applying electric
power to the piezoelectric crystals 180, which in turn, cause horn
150 to ultrasonically vibrate and/or amplify the movement, which in
turn, ultrasonically vibrates the needle 110. The electric power is
defined by a number of parameters, such as signal frequency and
amplitude, and if the power is applied in pulses, then the
parameters can further include pulse width, shape, size, duty
cycle, amplitude, and so on. These parameters are controlled by a
control unit. An example of controlling such parameters is
described in U.S. Pat. No. 7,169,123 to Kadziauskas, et al., which
is hereby incorporated by reference in its entirety.
[0022] Vibration of needle 110 and horn 150 of handpiece 100
generates significant heat at the tip of the needle, which may
damage tissue near the needle. This significant limitation is
overcome by the present invention.
[0023] The present invention relates to using one or more MEMS
devices to generate movement of a needle of a handpiece. MEMS
devices integrate mechanical and electrical structures, sensors,
and/or actuators on a silicon substrate using microfabrication. The
combination of components allows a system to gather and process
information, decide on a course of action, and control the
surrounding environment. The benefits of such a device include
increased affordability, functionality, and performance of
products. MEMS work by sensors that measure mechanical, thermal,
biological, chemical, magnetic, and/or optical signals from the
environment. The microelectronic integrated circuits act as the
"brains" of the system (the decision-making part of the system), by
processing the information from the sensors; and the actuators help
the system respond by moving, positioning, pumping, filtering, or
somehow controlling the surrounding environment to achieve its
purpose.
[0024] MEMS devices have a characteristic length between 1 micron
and 1 mm. MEMS: Design and Fabrication, edited by Mohamed
Gad-el-Hak, 2.sup.nd Edition, November 2005, which is hereby
incorporated by reference in its entirety. There are different
varieties of MEMS devices, including microsensors, micromotors, and
microgears. Id. Current manufacturing techniques for MEMS devices
include surface silicon micromachining (depositing thin films on
the surface); bulk silicon micromachining (forming mechanical
structures in the silicon substrates--etching through the wafer);
lithography, eletrodeposition, and plastic molding; and
electrodischarge machining. Id.
[0025] According to an embodiment, using one or more MEMS devices,
a needle of a handpiece can be oscillated to achieve similar
movement of a needle of an ultrasound handpiece. Traditional
deposition and lithography used in microchip design today can be
applied to create a microchip attached to a needle of a handpiece
that vibrates the needle in any desired direction, including, but
not limited to, transversal (side-to-side), torsional, and
longitudinal. In traditional deposition and lithography practices
two dissimilar materials are used, commonly referred to as dopants.
Dopants are deposited onto a wafer using a variety of techniques
well known in the art. The dopants either have a positive or a
negative charge; and the dopants are separated by a channel.
Applying a voltage or current to one of the doped sides causes the
other side to be attracted to the side where the current is
applied. By removing the voltage or current from the same side
causes the sides to move away. Repeating this application of
voltage or current creates motion. In addition to electrostatic
attraction and repulsion, other forms of generating force or
movement using MEMS may be employed with the present invention,
including but not limited to thermal and magnetic actuation.
[0026] The present invention also solves many problems associated
with ultrasound phaco handpieces. First, using one or more MEMS
devices to actuate the needle of a handpiece reduces manufacturing
time and costs. These reductions also make it possible to
manufacture a single use disposable handpieces that provide
additional safety to the patient. Disposable handpieces may also
reduce the amount of metal used with the handpiece. Second, using
one or more MEMS devices enables finer control of the movement of
the distal end of the needle, which promotes safer cataractic lens
removal. Finer control allows for a safer procedure by preventing
damage to tissue, including but not limited to tissue surrounding
the incision, the capsular bag, and other structures of the eye
that may be exposed to the needle of the handpiece. With MEMS,
movement of the distal end of the needle is always a known quantity
based on manufacturing processes. Without being limited to a
theory, use of one or more MEMS devices coupled with a horn and/or
a needle may cause the tip of the needle to oscillate and emulsify
the lens by mechanical break down of the cataractic lens, e.g. a
jackhammer. In an embodiment, multiple MEMS devices may be coupled
with a horn and/or needle to cause the tip of the needle to move in
a single direction and/or multiple directions. In an embodiment, 5
to 6 MEMS devices may be used for movement in a single direction or
in multiple directions. Each MEMS device may provide any desired
tip excursion, including but not limited to 1 mm to 2 mm.
[0027] MEMS devices of the present invention differ from standard
ultrasonic handpieces in many ways, including the different phase
angles and frequencies are removed and replaced with voltage and
current for controlling velocity and direction.
[0028] FIG. 2 illustrates an embodiment of the present invention.
MEMS system 200 includes MEMS device 220 and horn 250. MEMS device
220 comprises dopant side 240 and dopant side 230. Dopant side 240
or dopant side 230 may be positive or negative as long as one side
is positive and the other is negative. Channel 225 is located
between dopant side 240 and dopant side 230. The shape and/or size
of channel 225, dopant side 230, and/or dopant side 240 may be
changed to create different directions of movement.
[0029] FIG. 3 illustrates another embodiment of the present
invention. In FIG. 3, MEMS system 300 comprises horn 350 and MEMS
devices 320, wherein horn 350 is capable of being moved in at least
two directions--transversal direction 380 and longitudinal
direction 370. The movement of horn 350 causes a needle coupled
with horn 350 to move in the same directions as horn 350. MEMS
device 320 may be coupled with horn 350 via linkages 315. Each MEMS
device 320 may be activated at the same time or at different times
to achieve a desired movement of horn 350 and a needle coupled with
horn 350.
[0030] FIG. 4 illustrates another embodiment of the present
invention. Specifically, FIG. 4 shows MEMS system 400. MEMS system
400 includes MEMS device 420 and horn 450. When MEMS devices 420
are activated, horn 450 is rotated along its longitudinal axis as
shown by rotational direction 490. MEMS devices 420 may be coupled
with horn 450 via linkages 415. MEMS devices 420 are capable of
moving in directions 410 and 430. Movement of MEMS devices 420 in a
normal direction to the longitudinal axis of horn 450 causes horn
450 to move in rotational direction 490.
[0031] FIG. 5 illustrates another embodiment where MEMS devices 520
of MEMS system 500 are coupled with horn 550 via linkages 515 on
the outer surface 530 of horn 550. One or more MEMS devices 520 may
be coupled with outer surface 530 of horn 550. MEMS devices 520 may
also be coupled with born 550 via pads 505.
[0032] FIG. 6 illustrates another embodiment where MEMS system 600
comprises multiple MEMS devices 620, multiple pads 630, and
multiple linkages 615. Horn 650 may be coupled with multiple MEMS
devices 620 to generate movement in multiple directions. As
illustrated in FIG. 6, three MEMS devices 620 are coupled with horn
650 via linkages 615 and pad 630. These three MEMS devices 620 are
capable of generating movement of horn 650 in longitudinal
direction 640 (along a longitudinal axis of horn 650). One MEMS
device 620 may be coupled with horn 650 via linkages 615 and pad
630. This MEMS device 620 is capable of generating movement of horn
650 in transverse direction 660 (perpendicular to a longitudinal
axis of horn 650). Linkages 615 may be coupled with an outer
surface or end of horn 650. Linkages 615 may also be coupled with a
surface of pads 630. Linkages 615 may be of any shape or size. Pads
630 may also be of any shape or size to accommodate the use of one
or more MEMS devices 620.
[0033] The linkages (315, 415, and 515) may be of any size or shape
to enable coupling of one or more MEMS devices (220, 320, 420, and
520) with a horn (150, 250, 350, 450, and 550) and/or a needle. The
linkages may couple one or more MEMS device with one or more pads
(505), a needle, and/or horn by any orientation and on any location
of the MEMS device, pads, and/or horn in order to achieve the
desired directional movement, amount of movement, and design of the
handpiece. The linkages may also be coupled directly with an outer
surface of a needle or a horn. The linkage may be of any material
known in the art, including but not limited to all ferrous and
nonferrous metals.
[0034] In an embodiment, an asymmetric MEMS unit may be used. A
single MEMS device may generate all of the movement required,
including in an asymmetric fashion by asymmetrical coupling one or
more linkages to the horn and/or needle. With one pulse through the
MEMS device an expansion and contraction movement will happen. The
amount of force may be increased or decreased depending upon the
number of MEMS devices used for a particular directional
movement.
[0035] According to another embodiment, the MEMS devices may also
be used with a vitrectomy cutter. An example of a vitrectomy cutter
is illustrated in U.S. Pat. No. 6,575,990 (Wang, et al.), which is
hereby incorporated by reference in its entirety. Current
vitrectomy cutters rely on air supply to generate the movement of
the cutting blade to cut the vitreous. By using one or more MEMS
devices to actuate the movement of the cutting blade, the problems
associated with currently used vitrectomy cutters may be reduced,
such as, but not limited to adjusting the air pressure depending
upon the altitude at which the surgery is performed. Moreover,
eliminating the air supply would make the machines more compact and
portable, thereby reducing the overall cost of the machines.
[0036] In FIG. 7 a vitrectomy cutter known in the art is
illustrated. Vitrectomy cutter 700 includes handle 710 coupled with
needle body 720. Needle body 720 comprises one or more ports 730.
Housed within needle body 720 is one or more blades 810 (see FIG.
8) that may pass over the one or more ports 730 of needle body 720,
such that any vitreous that enters port 730 may be cut by the one
or more blades 810. The one or more blades act as a guillotine.
[0037] In FIG. 8, a MEMS device system of the present invention is
illustrated. MEMS device system 800 includes MEMS device 820 and
blade 810. MEMS device system 800 may be housed within needle body
720 and/or handle 710. One or more MEMS devices 820 may be coupled
with one or more blades 810. Activation of one or more MEMS devices
820 causes movement of blade 810 in direction 830 causing blade 810
to act as a guillotine to cut the vitreous. The MEMS devices may be
coupled with the one or more blades directly or via a pad/linkage
system as described herein. As shown in FIG. 8, blade 810 is
coupled with MEMS device 820 via linkage 815. As discussed above,
the linkages (e.g. 815) may be of any size or shape to enable
coupling of one or more MEMS devices (820) with blade 810 and/or
one or more pads.
[0038] MEMS devices of the present invention may be made of any
material known in the art, including but not limited to
polycrystalline silicon. The size of the MEMS devices may be of any
size and shape that provides the necessary movement of the needle
and fits within a standard sized handpiece, handle, and/or needle
body.
[0039] As described herein, one or more MEMS devices may be coupled
with a needle instead of a horn. In some embodiments, a needle and
a horn may be one unit and referred to as a horn or a needle.
[0040] The present invention provides more reliability and is more
cost effective due to the manufacturing process, e.g. cmos
manufacturing, resulting in less failures and returns. In an
embodiment, a phacoemulsification handpiece has one or more MEMS
devices and is disposable. A disposable handpiece would reduce the
need for sterilization and minimize the risk of
cross-contamination.
[0041] All references cited herein are hereby incorporated by
reference in their entirety including any references cited
therein.
[0042] Although the present invention has been described in terms
of specific embodiments, changes and modifications can be carried
out without departing from the scope of the invention which is
intended to be limited only by the scope of the claims.
* * * * *