U.S. patent application number 11/033043 was filed with the patent office on 2005-12-22 for tissue remover and method.
Invention is credited to Rizoiu, Ioana M..
Application Number | 20050283143 11/033043 |
Document ID | / |
Family ID | 29738679 |
Filed Date | 2005-12-22 |
United States Patent
Application |
20050283143 |
Kind Code |
A1 |
Rizoiu, Ioana M. |
December 22, 2005 |
Tissue remover and method
Abstract
An electromagnetically induced cutting mechanism provides
accurate cutting operations on hard or soft tissues. The
electromagnetically induced cutter is adapted to interact with
atomized fluid particles. A tissue remover comprises an aspiration
cannula housing a fluid and energy guide for conducting
electromagnetically induced cutting forces to the site within a
patient's body for aspiration of hard or soft tissue. The cannula
is provided with a cannula distal end. The proximal end of the
cannula is provided with fluid flow connection to an aspiration
source. Separated hard or soft tissue and fluid are aspirated
through the cannula distal end and the cannula by an aspiration
source at the proximal end of the cannula. Methods of using such a
cutter for hard or soft tissue removal are also disclosed.
Inventors: |
Rizoiu, Ioana M.; (San
Clemente, CA) |
Correspondence
Address: |
STOUT, UXA, BUYAN & MULLINS LLP
4 VENTURE, SUITE 300
IRVINE
CA
92618
US
|
Family ID: |
29738679 |
Appl. No.: |
11/033043 |
Filed: |
January 10, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11033043 |
Jan 10, 2005 |
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10667921 |
Sep 22, 2003 |
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10667921 |
Sep 22, 2003 |
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09714479 |
Nov 15, 2000 |
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6669685 |
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09714479 |
Nov 15, 2000 |
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09188072 |
Nov 6, 1998 |
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6254597 |
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09188072 |
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08985513 |
Dec 5, 1997 |
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08985513 |
Dec 5, 1997 |
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08522503 |
Aug 31, 1995 |
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5741247 |
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09188072 |
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08995241 |
Dec 17, 1997 |
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08995241 |
Dec 17, 1997 |
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08575775 |
Dec 20, 1995 |
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5785521 |
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60064465 |
Nov 6, 1997 |
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60535182 |
Jan 8, 2004 |
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Current U.S.
Class: |
606/13 ;
604/35 |
Current CPC
Class: |
A61B 18/20 20130101;
B23K 26/0096 20130101; B23K 26/146 20151001; A61B 17/3203 20130101;
A61B 2218/008 20130101 |
Class at
Publication: |
606/013 ;
604/035 |
International
Class: |
A61B 018/20; A61M
001/00 |
Claims
1. A method for removing hard tissue from a patient comprising:
providing a tissue remover having a proximal end and a distal end,
and a fluid guide and an energy guide extending from the proximal
end towards the distal end; inserting the tissue remover through an
incision in the patient so that the distal end of the tissue
remover is in proximity to hard tissue; transmitting gas and fluid
through the fluid guide of the tissue remover; generating atomized
fluid particles in an interaction zone located in close proximity
to the distal end of the tissue remover by using the air and fluid
transmitted through the fluid and energy guide; providing
electromagnetic energy from an energy source to an electromagnetic
energy transmitter operatively mounted within the fluid and energy
guide; and transmitting the electromagnetic energy from an output
end of the energy transmitter into the interaction zone, the
electromagnetic energy having a wavelength which is substantially
absorbed by a portion of atomized fluid particles in the
interaction zone, the absorption of the electromagnetic energy by
the portion of atomized fluid particles causing the portion of
atomized fluid particles to expand and impart disruptive cutting
forces onto the tissue in close proximity to the distal end of the
tissue remover.
2. The method of claim 1, further comprising a step of aspirating
the hard tissue removed by the tissue remover.
3. The method of claim 1, wherein the hard tissue is removed by
eroding the hard tissue with the forces generated by the
electromagnetic energy and the atomized fluid particles.
4. The method of claim 1, wherein the hard tissue comprises
bone.
5. The method of claim 1, wherein the hard tissue is removed in an
arthroscopic procedure of the patient's knee.
6. The method of claim 1, wherein the hard tissue is removed
without inducing thermal damage to the surrounding tissue.
7. The method of claim 1, wherein the energy source comprises an
erbium, chromium, yttrium, scandium, gallium garnet (Er, Cr:YSGG)
solid state laser.
8. The method of claim 1, wherein the energy source comprises a
CO.sub.2 laser.
9. The method of claim 1, wherein the fluid comprises water.
10. The method of claim 1, wherein the fluid comprises an
anesthetic.
11. The method of claim 1, wherein the fluid comprises a saline
solution.
12. The method of claim 1, wherein the fluid comprises
epinephrine.
13. A system for removing hard tissue from a knee of a patient,
comprising: a tissue remover disposed in a cannula having a
proximal end and a distal end that is structured to be inserted
into a patient's knee joint, the tissue remover having a fluid
guide and an energy guide extending towards the distal end of the
cannula, wherein the fluid guide is structured to guide fluid and
gas toward the distal end of the cannula to create atomized fluid
particles; and an energy source to provide electromagnetic energy
through the energy guide to an energy transmitter that transmits
the electromagnetic energy to an interaction zone located in close
proximity to the distal end of the cannula where the
electromagnetic energy is absorbed by atomized fluid particles in
the interaction zone to impart erosive forces to cause removal of
hard tissue from the patient's knee.
14. The system of claim 13 further comprising an aspirator attached
to the cannula to aspirate hard tissue removed by the tissue
cutter.
15. The system of claim 14, wherein the aspirator is disposed in a
lumen of the cannula to cause the hard tissue to be aspirated
through the cannula.
16. The system of claim 13, wherein the fluid guide and energy
transmitter are positioned so that the interaction zone is in
proximity to the hard tissue to be removed from the knee without
inducing thermal damage to the surrounding knee tissue.
17. The system of claim 13, wherein the energy source comprises an
erbium, chromium, yttrium, scandium, gallium garnet (Er, Cr:YSGG)
solid state laser.
18. The system of claim 13, wherein the energy source comprises a
CO.sub.2 laser.
19. The system of claim 13, wherein the cannula is formed of a
medical grade plastic.
20. The system of claim 13, wherein the cannula is formed of a
stainless steel.
21. The system of claim 13, wherein the energy transmitter is a
fiber optic delivery system.
22. The system of claim 13, wherein the fluid comprises water.
23. The system of claim 13, wherein the fluid comprises an
anesthetic.
24. The system of claim 13, wherein the fluid comprises a saline
solution.
25. The system of claim 13, wherein the fluid comprises
epinephrine.
26. The system of claim 13, wherein the energy source comprises an
ER:YAG laser.
27. The system of claim 13, wherein the fluid comprises epinephrine
and an anesthetic.
28. The system of claim 13, further comprising a camera attached to
the cannula to provide images of the knee joint to a user of the
system.
29. A method for removing hard tissue from a knee of a patient
comprising: providing a tissue remover having a proximal end and a
distal end, and a fluid and energy guide extending from the
proximal end towards the distal end; inserting the tissue remover
through an incision so that the distal end of the tissue remover is
in proximity to the patient's femur; transmitting gas and fluid
through the fluid guide of the tissue remover; generating atomized
fluid particles in an interaction zone located in close proximity
to the distal end of the tissue remover by using the air and fluid
transmitted through the fluid and energy guide; providing
electromagnetic energy from an energy source to an electromagnetic
energy transmitter operatively mounted within the fluid and energy
guide; transmitting the electromagnetic energy from an output end
of the energy transmitter into the interaction zone, the
electromagnetic energy having a wavelength which is substantially
absorbed by a portion of atomized fluid particles in the
interaction zone, the absorption of the electromagnetic energy by
the portion of atomized fluid particles causing the portion of
atomized fluid particles to expand and impart disruptive cutting
forces that erode the patient's femur to expose a surface of the
patient's tibia; removing a portion of the meniscus overlying the
surface of the tibia by transmitting the electromagnetic energy to
the energy transmitter to create cutting forces to erode the
patient's meniscus; and removing a portion of the patient's tibia
to create a receptacle for a prosthetic implant.
30. The method of claim 29, further comprising a step of removing
damaged tissue from the patient's femur to create an opening for a
femoral prosthetic implant.
31. The method of claim 29, further comprising a step of applying
an adhesive to the receptacle in the tibia to provide adhesion of
the prosthetic implant to the tibia.
32. The method of claim 28, further comprising a step of applying
adhesive to the receptacle in the tibia and the opening in the
femur to provide adhesion of the prosthetic implants and the
bones.
33. The method of claim 32, further comprising a step of securing
prosthetic implants to the adhesive disposed in the femur and the
tibia of the patient.
34. The method of claim 27, wherein the tissue is removed by
scanning the distal end of the tissue remover along the surface of
the tissue without directly contacting the tissue.
35. The method of claim 27, wherein the method is performed for
knee replacement surgery.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/535,182, filed Jan. 8, 2004 and entitled TISSUE
REMOVE AND METHOD, the contents of which are expressly incorporated
herein by reference. This application is a continuation-in-part of
co-pending U.S. application Ser. No. 10/667,921 filed Sep. 22, 2003
and entitled TISSUE REMOVER AND METHOD, which is a continuation of
co-pending U.S. application Ser. No. 09/714,479 filed Nov. 15, 2000
and entitled TISSUE REMOVER AND METHOD, which is a
continuation-in-part of U.S. application Ser. No. 09/188,072, filed
Nov. 6, 1998, now U.S. Pat. No. 6,254,597 and entitled TISSUE
REMOVER AND METHOD, the contents of all of the above which are
expressly incorporated herein by reference. U.S. application Ser.
No. 09/188,072 claims the benefit of U.S. Provisional Application
No. 60/064,465 filed Nov. 6, 1997 and entitled ELECTROMAGNETICALLY
INDUCED MECHANICAL CUTTER FOR LYPOSUCTION the contents of which are
expressly incorporated herein by reference. U.S. application Ser.
No. 09/188,072 is also a continuation-in-part of U.S. application
Ser. No. 08/985,513 filed Dec. 5, 1997 and entitled USER
PROGRAMMABLE COMBINATION OF ATOMIZED PARTICLES FOR
ELECTROMAGNETICALLY INDUCED CUTTING, which is a continuation of
U.S. application Ser. No. 08/522,503 filed Aug. 31, 1995 and
entitled USER PROGRAMMABLE COMBINATION OF ATOMIZED PARTICLES FOR
ELECTROMAGNETICALLY INDUCED CUTTING which issued into U.S. Pat. No.
5,741,247, both of which are commonly assigned and the contents of
which are expressly incorporated herein by reference. U.S.
application Ser. No. 09/188,072 is also a continuation-in-part of
co-pending U.S. application Ser. No. 08/995,241, filed Dec. 17,
1997 and entitled FLUID CONDITIONING SYSTEM, which is a
continuation of U.S. application Ser. No. 08/575,775, filed Dec.
20, 1995 and entitled FLUID CONDITIONING SYSTEM which issued into
U.S. Pat. No. 5,785,521, both of which are commonly assigned and
the contents of which are expressly incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to medical apparatus
and, more particularly, to methods and apparatus for cutting and
removing soft or hard tissue from patients.
[0004] 2. Description of Related Art
[0005] Turning to FIG. 1, an example of one of many varying types
of prior art optical cutters includes a fiber guide tube 5, a water
line 7, an air line 9, and an air knife line 11 for supplying
pressurized air. A cap 15 fits onto the hand-held apparatus 13 and
is secured via threads 17. The fiber guide tube 5 abuts within a
cylindrical metal piece 19. Another cylindrical metal piece 21 is a
part of the cap 15. The pressurized air from the air knife line 11
surrounds and cools the laser as the laser bridges the gap between
the two metal cylindrical objects 19 and 21. Air from the air knife
line 11 flows out of the two exhausts 25 and 27 after cooling the
interface between elements 19 and 21.
[0006] The laser energy exits from the fiber guide tube 23 and is
applied to a target surface of the patient. Water from the water
line 7 and pressurized air from the air line 9 are forced into the
mixing chamber 29. The air and water mixture is very turbulent in
the mixing chamber 29, and exits this chamber through a mesh screen
with small holes 31. The air and water mixture travels along the
outside of the fiber guide tube 23, and then leaves the tube and
contacts the area of surgery.
[0007] Other examples of a wide array of prior art devices and
methods include U.S. Pat. No. 5,199,870 to Steiner et al. and U.S.
Pat. No. 5,267,856 to Wolbarsht et al. Other devices have existed
in the prior art for utilizing laser energy to perform soft tissue
procedures, wherein for example laser energy facilitates the
separation or manipulation of soft tissue in vivo. U.S. Pat. No.
4,985,027 to Dressel discloses one example of many various types of
devices in the field. According to this one example of a prior art
device, the contents of which are expressly incorporated herein by
reference, a tissue remover utilizes laser energy from a Nd:YAG to
separate tissue held within a cannula. Use of the Nd:YAG laser for
in vivo tissue removal may in some ways be inefficient, since the
energy from the Nd:YAG laser may not be highly absorbed by water.
Further, the Nd:YAG laser and other lasers, such as an Er:YAG
laser, may in some configurations use thermal heating as the sole
cutting mechanism. Adjacent tissue may in certain implementations
be charred or thermally damaged and, further, noxious and
potentially toxic smoke may in some instances be generated during
the thermal cutting operations.
[0008] Many devices also have existed in the prior art for
performing endoscopic surgical procedures, wherein for example one
or more catheters or cannulas are inserted through a small opening
in a patient's skin to provide various working passageways through
which small surgical instruments can be advanced into the patient
during surgery. Specific endoscopic applications include
arthroscopic surgery, neuroendoscopic surgery, laparoscopic
surgery, and liposuction. Arthroscopic surgery refers to surgery
related to, for example, joints such as the shoulders and knees.
One example of a prior-art device, which has been used during the
implementation of an arthroscopic surgical procedure, is an
arthroscopic shaver. The arthroscopic shaver entails the
application of a spinning tube-within-a-tube that concurrently
resects tissue while aspirating debris and saline from within the
operative site. One such arthroscopy system is the DYONICS.RTM.
Model EP-1 available from Smith & Nephew Endoscopy, Inc., of
Andover, Mass. Cutting with such an instrument is obtained by
driving the inner tube at a high speed using a motor. Surrounding
the tubular blade is an outer tubular membrane having a hub at its
proximal end adapted to meet with the handle. Performing an
arthroscopic procedure with a high-speed rotary shaver such as the
one mentioned may in certain instances result in extensive trauma
to the tissue and blood vessel laceration.
SUMMARY OF THE INVENTION
[0009] The present invention discloses an electromagnetically
induced cutting mechanism, which can provide accurate cutting
operations on hard and soft tissues, and other materials as well.
Soft tissues may include fat skin, mucosa, gingiva, muscle, heart,
liver, kidney, brain, eye, and vessels, and hard tissue may include
tooth enamel, tooth dentin, tooth cementum, tooth decay, amalgam,
composites materials, tarter and calculus, bone and cartilage.
[0010] In accordance with the present invention, an
electromagnetically induced cutter is used to perform surgical
procedures, using cannulas and catheters, also known as endoscopic
surgical procedures. Endoscopic surgical applications for the
electromagnetic cutter of the present invention include
arthroscopic surgery, neuroendoscopic surgery, laparoscopic
surgery, liposuction and other endoscopic surgical procedures. The
electromagnetically induced cutter is suitable to be used for
arthroscopic surgical procedures in the treatment of, for example:
(i) torn menisci, anterior cruciate, posterior cruciate, patella
malalignment, synovial diseases, loose bodies, osteal defects,
osteophytes, and damaged articular cartilage (chondromalacia) of
the knee; (ii) synovial disorders, labial tears, loose bodies,
rotator cuff tears, anterior impingement and degenerative joint
disease of the acromioclavicular joint and diseased articular
cartilage of the shoulder joint; (iii) synovial disorders, loose
bodies, osteophytes, and diseased articular cartilage of the elbow
joint; (iv) synovial disorder, loose bodies, ligament tears and
diseased articular cartilage of the wrist; (v) synovial disorders,
loose bodies, labrum tears and diseased articular cartilage in the
hip; and (vi) synovial disorders, loose bodies, osteophytes,
fractures, and diseased articular cartilage in the ankle.
[0011] The electromagnetically induced cutter of the present
invention is disposed within a carnula or catheter and positioned
therein near the surgical site where the treatment is to be
performed. In accordance with one aspect of the present invention,
a diameter of the cannula or catheter is minimized to reduce the
overall cross-sectional area of the cannula or catheter for the
performance of minimally invasive procedures. In accordance with
another aspect of the present invention, a plurality of catheters
may be formed together for various purposes. For example, in
arthroscopic knee surgery, one cannula can be configured to
incorporate the cutting device and suction, and a separate cannula
can be configured to incorporate the imaging system that monitors
the treatment site during the procedure. In accordance with yet
another aspect of the present invention, the suction, cutting
device and imaging device may all be incorporated within the same
cannula. Another aspect of the present invention may provide for an
additional third cannula for supplying air to the treatment
site.
[0012] The electromagnetically induced cutter of the present
invention may be capable of providing extremely fine and smooth
incisions, irrespective of the cutting surface. Additionally, a
user programmable combination of atomized particles may allow for
user control of various cutting parameters. The various cutting
parameters may also be controlled by changing spray nozzles and
electromagnetic energy source parameters. Applications for the
present invention include medical procedures, such as arthroscopic
surgery, neuroendoscopic surgery, laparoscopic surgery, liposuction
and dental, and other environments where an objective may be to
precisely remove surface materials with attenuation or elimination
or one or more of thermal damage, uncontrolled cutting parameters,
and/or rough surfaces inappropriate for ideal bonding. Certain
implementations of the present invention further may not require
films of water or particularly porous surfaces to obtain accurate
and controlled cutting. Since in certain embodiments thermal
heating may not be used, or may not be used exclusively, as the
cutting mechanism, thermal damage may be attenuated or
substantially eliminated. Moreover, in certain implementations,
adjacent tissue may not be charred or thermally damaged, or charred
or thermally damaged less, and, further, noxious and potentially
toxic smoke may be attenuated or completely eliminated.
[0013] The electromagnetically induced cutter of the present
invention includes an electromagnetic energy source, which focuses
electromagnetic energy into a volume of air adjacent to a target
surface. The target surface may comprise tissue within a cannula,
for example. A user input device specifies a type of cut to be
performed, and an atomizer responsive to the user input device
places a combination of atomized fluid particles into the volume of
air. The electromagnetic energy is focused into the volume of air,
and the wavelength of the electromagnetic energy is selected to be
substantially absorbed by the atomized fluid particles in the
volume of air. Upon absorption of the electromagnetic energy the
atomized fluid particles expand and impart cutting forces onto the
target surface.
[0014] The electromagnetically induced cutter of the present
invention can provide an improvement over prior-art high-speed
rotary shavers, such as the above-mentioned arthroscopic shaver,
since the electromagnetically induced cutter of the present
invention may not directly contact the tissue to cause trauma and
blood vessel laceration. Instead, cutting forces may remove small
portions of the tissue through a process of fine or gross erosion
depending on the precision required. This process can be applied to
precisely and cleanly shave, reshape, cut through or remove, for
example, cartilage, fibrous cartilage, or bone without the heat,
vibration, and pressure associated with rotary shaving instruments.
The system can be used without air and/or water, in order to
coagulate bleeding tissue. In accordance with another application
of the electromagnetic cutter, a spray of water can be the carrier
of an anti-coagulant medication that may also contribute to tissue
coagulation.
[0015] Other endoscopic applications for the electromagnetically
induced cutter may include neurosurgical and abdominal surgical
applications. In neurosurgery, the electromagnetically induced
cutter may be suited for removing brain tissue lesions, as well as
for the cutting of various layers of tissue to reach the locations
of the lesions. The entire method of creating an access through the
scalp into the bone and through the various layers of tissue that
protect the brain tissue may be accomplished with the
electromagnetically induced cutter of the present invention.
[0016] The invention, together with additional features and
advantages thereof may best be understood by reference to the
following description taken in connection with the accompanying
illustrative drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is an example of one of many types of conventional
optical cutter apparatuses;
[0018] FIG. 2 is a schematic block diagram illustrating an example
of an electromagnetically induced cutter of the present
invention;
[0019] FIG. 3 illustrates an example of one embodiment of the
electromagnetically induced cutter of the present invention;
[0020] FIGS. 4a and 4b illustrate examples of other embodiments of
electromagnetically induced cutters;
[0021] FIG. 5 illustrates an example of a control panel for
programming the combination of atomized fluid particles according
to the present invention;
[0022] FIG. 6 is a plot of particle size versus fluid pressure in
accordance with one implementation of the present invention;
[0023] FIG. 7 is a plot of particle velocity versus fluid pressure
in accordance with one implementation of the present invention;
[0024] FIG. 8 is a schematic diagram illustrating examples of a
fluid particle, a source of electromagnetic energy, and a target
surface according to an aspect of the present invention;
[0025] FIG. 9a is a side cut-away elevation view of a tissue
remover of an embodiment of the present invention with a cannula
tip;
[0026] FIG. 9b is a side cut-away elevation view of a tissue
remover of an embodiment of the present invention with an open
cannula end;
[0027] FIG. 10a is an exploded longitudinal section view of the
distal end of the cannula with a cannula tip;
[0028] FIG. 10b is an exploded longitudinal section view of the
distal end of the cannula with an open cannula end;
[0029] FIG. 11a is an exploded view similar to FIG. 10a, showing an
embodiment of an electromagnetically induced cutter disposed
adjacent the soft tissue aspiration inlet port;
[0030] FIG. 11b is an exploded view similar to FIG. 10b, showing an
electromagnetically induced cutter disposed within the open
cannula;
[0031] FIG. 11c is a block diagram illustrating an implementation
of an imaging tube and imaging device disposed within the
cannula;
[0032] FIG. 12 is a partial exploded longitudinal section view of
the handle and proximal end cap showing the laser fiber and sources
of fluids within the fluid and laser guide tube;
[0033] FIG. 13 is a partial exploded longitudinal section of an
embodiment of a guide tube transmission coupler positioned within
the handle; and
[0034] FIG. 14 is a cut-away detail of an implementation of an
embodiment of the laser soft tissue device of the present invention
illustrated in position for performing liposuction within a fatty
deposit of a body intermediate overlying epidermal layer and
underlying muscle layer.
DETAILED DESCRIPTION OF THE INVENTION
[0035] FIG. 2 is a block diagram illustrating an
electromagnetically induced cutter in accordance with an embodiment
of the present invention. An electromagnetic energy source 51 is
coupled to both a controller 53 and a delivery system 55. The
delivery system 55 imparts forces onto the target surface 57. As
presently embodied, the delivery system 55 comprises a fiber optic
guide for routing the laser 51 into an interaction zone 59, located
above the target surface 57. The delivery system 55 further
comprises an atomizer for delivering user-specified combinations of
atomized fluid particles into the interaction zone 59. The
controller 53 controls various operating parameters of the laser
51, and further controls specific characteristics of the
user-specified combination of atomized fluid particles output from
the delivery system 55.
[0036] FIG. 3 shows a simple embodiment of the electromagnetically
induced cutter of the present invention, in which a fiber optic
guide 61, an air tube 63, and a water tube 65 are placed within a
hand-held housing 67. As used herein, the term "water" is intended
to encompass various modified embodiments of liquids such as
distilled water, deionized water, sterile water, tap water or water
that has a controlled number of colony forming units (CFU) for the
bacterial count, etc. For instance, drinking water is often
chemically treated to a level where there are no more than 500
CFU/ml and in some cases between 100-200 CFU/ml. The water tube 65
is operated under a relatively low pressure, and the air tube 63 is
operated under a relatively high pressure. The laser energy from
the fiber optic guide 61 focuses onto a combination of air and
water, from the air tube 63 and the water tube 65, at the
interaction zone 59. As used herein, mentions of air and/or water
are intended to encompass various modified embodiments of the
invention, including various biocompatible fluids used with or
without the air and/or water, and including equivalents,
substitutions, additives, or permutations thereof. For instance, in
certain modified embodiments other biocompatable fluids may be used
instead of air and/or water. Atomized fluid particles in the air
and water mixture absorb energy from the laser energy of the fiber
optic tube 61, and explode. The explosive forces from these
atomized fluid particles impart cutting forces onto the target
surface 57.
[0037] Turning back to FIG. 1, the prior art optical cutter focuses
laser energy onto a target surface at an area A, for example, and
the electromagnetically induced cutter of the present invention can
in certain embodiments be configured to focus laser energy into an
interaction zone B, for example. The prior art optical cutter may
use the laser energy directly to cut tissue, and the
electromagnetically induced cutter of the present invention in
certain configurations uses the laser energy to expand atomized
fluid particles to thus impart at least partial cutting forces onto
or into the target surface. The example of a prior art optical
cutter may use a large amount of laser energy to cut the area of
interest, and also may use a large amount of water to both cool
this area of interest and remove cut tissue.
[0038] In contrast, the electromagnetically induced cutter of the
present invention may in some implementations use a relatively
small amount of water and, further, may be configured to use only a
small amount of laser energy to expand atomized fluid particles
generated from the water. According to the electromagnetically
induced cutter of the present invention, water may not be needed to
cool the area of surgery, since the exploded atomized fluid
particles bay be cooled by exothermic reactions before they contact
the target surface. Thus, atomized fluid particles of certain
embodiments of the present invention can be heated, expanded, and
cooled before contacting the target surface. The
electromagnetically induced cutter of certain embodiments of the
present invention may thus be capable of cutting without charring
or discoloration.
[0039] FIG. 4a illustrates an embodiment of the electromagnetically
induced cutter. The atomizer for generating atomized fluid
particles comprises a nozzle 71, which may be interchanged with
other nozzles (not shown) for obtaining various spatial
distributions of the atomized fluid particles, according to the
type of cut desired. A second nozzle 72, shown in phantom lines,
may also be used. The cutting power of the electromagnetically
induced cutter is further controlled by a user control 75 (FIG.
4b). In a simple embodiment, the user control 75 controls the air
and water pressure entering into the nozzle 71. The nozzle 71 is
thus capable of generating many different user-specified
combinations of atomized fluid particles and aerosolized
sprays.
[0040] Intense energy is emitted from the fiber optic guide 23.
This intense energy can be generated from a coherent source, such
as a laser. In an illustrated embodiment, the laser comprises
either an erbium, chromium, yttrium, scandium, gallium garnet (Er,
Cr:YSGG) solid state laser, which generates electromagnetic energy
having a wavelength in a range of 2.70 to 2.80 microns, or an
erbium, yttrium, aluminum garnet (Er:YAG) solid state laser, which
generates electromagnetic energy having a wavelength of 2.94
microns. The Er, Cr:YSGG solid state laser can have a wavelength of
approximately 2.78 microns and the Er:YAG solid state laser has a
wavelength of approximately 2.94 microns.
[0041] While comprising water in an illustrated embodiment, the
fluid emitted from the nozzle 71 may comprise other fluids with
appropriate wavelengths of the electromagnetic energy source being
selected to allow for high absorption by the fluid. Other possible
laser systems include an erbium, yttrium, scandium, gallium garnet
(Er:YSGG) solid state laser, which generates electromagnetic energy
having a wavelength in a range of 2.70 to 2.80 microns; an erbium,
yttrium, aluminum garnet (Er:YAG) solid state laser, which
generates electromagnetic energy having a wavelength of 2.94
microns; chromium, thulium, erbium, yttrium, aluminum garnet
(CTE:YAG) solid state laser, which generates electromagnetic energy
having a wavelength of 2.69 microns; erbium, yttrium orthoaluminate
(Er:YALO3) solid state laser, which generates electromagnetic
energy having a wavelength in a range of 2.71 to 2.86 microns;
holmium, yttrium, aluminum garnet (Ho:YAG) solid state laser, which
generates electromagnetic energy having a wavelength of 2.10
microns; quadrupled neodymium, yttrium, aluminum garnet (quadrupled
Nd:YAG) solid state laser, which generates electromagnetic energy
having a wavelength of 266 nanometers; argon fluoride (ArF) excimer
laser, which generates electromagnetic energy having a wavelength
of 193 nanometers; xenon chloride (XeCl) excimer laser, which
generates electromagnetic energy having a wavelength of 308
nanometers; krypton fluoride (KrF) excimer laser, which generates
electromagnetic energy having a wavelength of 248 nanometers; and
carbon dioxide (CO2), which generates electromagnetic energy having
a wavelength in a range of 9.0 to 10.6 microns. Water may be chosen
as the preferred fluid because of its biocompatibility, abundance,
and low cost. The actual fluid used may vary as long as it is
properly matched (meaning it is highly absorbed) to the selected
electromagnetic energy source (i.e. laser) wavelength.
[0042] The electromagnetic energy source can be configured with the
repetition rate greater than 1 Hz, the pulse duration range between
1 picosecond and 1000 microseconds, and the energy greater than 1
millijoule per pulse. According to one operating mode of the
present invention, the electromagnetic energy source has a
wavelength of approximately 2.78 microns, a repetition rate of 20
Hz, a pulse duration of 140 microseconds, and an energy between 1
and 300 millijoules per pulse.
[0043] In one embodiment the electromagnetic energy source has a
pulse duration on the order of nanoseconds, which is obtained by
Q-switching the electromagnetic energy source, and in another
embodiment the electromagnetic energy source has a pulse duration
on the order of picoseconds, which is obtained by mode locking the
electromagnetic energy source. Q-switching is a conventional mode
of laser operation which is extensively employed for the generation
of high pulse power. The textbook, Solid-State Laser Engineering,
Fourth Extensively Revised and Updated Edition, by Walter Koechner
and published in 1996, the entire contents of which are expressly
incorporated herein by reference, discloses Q-switching laser
theory and various Q-switching devices. Q-switching devices
generally inhibit laser action during the pump cycle by either
blocking the light path, causing a mirror misalignment, or reducing
the reflectivity of one of the resonator mirrors. Near the end of
the flashlamp pulse, when maximum energy has been stored in the
laser rod, a high Q-condition is established and a giant pulse is
emitted from the laser. Very fast electronically controlled optical
shutters can be made by using the electro-optic effect in crystals
or liquids. An acousto-optic Q-switch launches an ultrasonic wave
into a block of transparent optical material, usually fused silica.
Chapter eight of the textbook, Solid-State Laser Engineering,
Fourth Extensively Revised and Updated Edition, discloses the
above-mentioned and other various Q-switching devices. Mode locking
is a conventional procedure which phase-locks the longitudinal
modes of the laser and which uses a pulse width that is inversely
related to the bandwidth of the laser emission. Mode locking is
discussed on pages 500-561 of the above-mentioned textbook
entitled, Solid-State Laser Engineering, Fourth Extensively Revised
and Updated Edition.
[0044] The atomized fluid particles can in certain implementations
provide at least a part of the cutting forces when they absorb the
electromagnetic energy within the interaction zone. In other
implementations, part or all of the cutting forces may stem from
other effects or mechanisms, such as thermal affects. The atomized
fluid particles, however, can provide a second function of cleaning
and cooling the fiber optic guide from which the electromagnetic
energy is output. The delivery system 55 (FIG. 2) for delivering
the electromagnetic energy includes a fiber optic energy guide or
equivalent which attaches to the laser system and travels to the
desired work site. Fiber optics or waveguides are typically long,
thin and lightweight, and are easily manipulated. Fiber optics can
be made of calcium fluoride (CaF), calcium oxide (CaO2), zirconium
oxide (ZrO2), zirconium fluoride (ZrF), sapphire, hollow waveguide,
liquid core, TeX glass, quartz silica, germanium sulfide, arsenic
sulfide, germanium oxide (GeO2), and other materials. Other
delivery systems include devices comprising mirrors, lenses and
other optical components where the energy travels through a cavity,
is directed by various mirrors, and is focused onto the targeted
cutting site with specific lenses. An embodiment of light delivery
for medical applications of the present invention can be through a
fiber optic conductor, because of its light weight, lower cost, and
ability to be packaged inside of a handpiece of familiar size and
weight to the surgeon, dentist, or clinician. In industrial
applications, non-fiber optic systems may be used.
[0045] The nozzle 71 is employed to create an engineered
combination of small particles of the chosen fluid. The nozzle 71
may comprise several different designs including liquid only, air
blast, air assist, swirl, solid cone, etc. When fluid exits the
nozzle 71 at a given pressure and rate, it is transformed into
particles of user-controllable sizes, velocities, and spatial
distributions. The nozzle may have spherical, oval, or other shaped
openings of any of a variety of different sizes, according to
design parameters.
[0046] FIG. 5 illustrates a control panel 77 for allowing
user-programmability of the atomized fluid particles. By changing
the pressure and flow rates of the fluid, for example, the user can
control the atomized fluid particle characteristics. These
characteristics may determine absorption efficiency of the laser
energy, and the subsequent cutting effectiveness of the
electromagnetically induced cutter. This control panel may
comprise, for example, a fluid particle size control 78, a fluid
particle velocity control 79, a cone angle control 80, an average
power control 81, a repetition rate 82 and a fiber selector 83.
[0047] The cone angle may be controlled, for example, by changing
the physical structure of the nozzle 71. Various nozzles 71 may be
interchangeably placed on the electromagnetically induced cutter.
Alternatively, the physical structure of a single nozzle 71 maybe
changed.
[0048] FIG. 6 illustrates a plot 85 of mean fluid particle size
versus pressure. According to this figure, when the pressure
through the nozzle 71 is increased, the mean fluid particle size of
the atomized fluid particles decreases. The plot 87 of FIG. 7 shows
that the mean fluid particle velocity of these atomized fluid
particles increases with increasing pressure.
[0049] According to one implementation of the present invention,
materials are removed from a target surface at least in part by
disruptive (e.g., mechanical) cutting forces, instead of by
conventional cutting forces which in some instances may comprise
purely thermal cutting forces. Laser energy may be used only to
induce forces onto the targeted material. Thus, the atomized fluid
particles can act as the medium for transforming the
electromagnetic energy of the laser into the energy required to
achieve the cutting effect of such an implementation of the present
invention. The laser energy itself in such embodiments may not be
directly absorbed by the targeted material. The interaction of the
present invention may in certain instances be safer, faster, and/or
eliminate the negative thermal side-effects typically associated
with certain conventional laser cutting systems.
[0050] The fiber optic guide 23 (FIG. 4a) can be placed into close
proximity of the target surface. This fiber optic guide 23,
however, does not actually contact the target surface. Since the
atomized fluid particles from the nozzle 71 are placed into the
interaction zone 59, the purpose of the fiber optic guide 23 is for
placing laser energy into this interaction zone, as well. One
feature of the present invention is the formation of the fiber
optic guide 23 of straight or bent sapphire. Regardless of the
composition of the fiber optic guide 23, however, another feature
of the present invention is the cleaning effect of the air and
water, from the nozzle 71, on the fiber optic guide 23.
[0051] The present inventors have found that this cleaning effect
is optimal when the nozzle 71 is pointed somewhat directly at the
target surface. For example, debris from the cutting are removed by
the spray from the nozzle 71.
[0052] Additionally, the present inventors have found that this
orientation of the nozzle 71, pointed toward the target surface,
enhances the cutting efficiency of the present invention. Each
atomized fluid particle contains a small amount of initial kinetic
energy in the direction of the target surface. When electromagnetic
energy from the fiber optic guide 23 contacts an atomized fluid
particle, the exterior surface of the fluid particle acts as a
focusing lens to focus the energy into the water particle's
interior. As shown in FIG. 8, the water particle 101 has an
illuminated side 103, a shaded side 105, and a particle velocity
107. The focused electromagnetic energy is absorbed by the water
particle 101, causing the interior of the water particle to heat
and explode rapidly. This exothermic explosion cools the remaining
portions of the exploded water particle 101. The surrounding
atomized fluid particles further enhance cooling of the portions of
the exploded water particle 101. A pressure-wave is generated from
this explosion. This pressure-wave, and the portions of the
exploded water particle 101 of increased kinetic energy, are
directed toward the target surface 107. The incident portions from
the original exploded water particle 101, which are now traveling
at high velocities with high kinetic energies, and the
pressure-wave, may in certain implementations to impart strong,
concentrated, forces onto the target surface 107.
[0053] These forces may cause the target surface 107 to break apart
from the material surface through a "chipping away" action. The
target surface 107 may not undergo, or may undergo a reduced amount
of, vaporization, disintegration, or charring. The chipping away
process can be repeated by the present invention until the desired
amount of material has been removed from the target surface
107.
[0054] The nozzle 71 can be configured to produce atomized sprays
with a range of fluid particle sizes narrowly distributed about a
mean value. The user input device for controlling cutting
efficiency may comprise a simple pressure and flow rate gauge 75
(FIG. 4b) or may comprise a control panel as shown in FIG. 5, for
example. Upon a user input for a high resolution cut, relatively
small fluid particles are generated by the nozzle 71. Relatively
large fluid particles are generated for a user input specifying a
low resolution cut. A user input specifying a deep penetration cut
causes the nozzle 71 to generate a relatively low density
distribution of fluid particles, and a user input specifying a
shallow penetration cut causes the nozzle 71 to generate a
relatively high density distribution of fluid particles. If the
user input device comprises the simple pressure and flow rate gauge
75 of FIG. 4b, then a relatively low density distribution of
relatively small fluid particles can be generated in response to a
user input specifying a high cutting efficiency. Similarly, a
relatively high density distribution of relatively large fluid
particles can be generated in response to a user input specifying a
low cutting efficiency.
[0055] Soft tissues may include fat, skin, mucosa, gingiva, muscle,
heart, liver, kidney, brain, eye, and vessels, and hard tissue may
include tooth enamel, tooth dentin, tooth cementum, tooth decay,
amalgam, composites materials, tarter and calculus, bone, and
cartilage. The term "fat" refers to animal tissue consisting of
cells distended with greasy or oily matter. Other soft tissues such
as breast tissue, lymphangiomas, and hemangiomas are also
contemplated. The hard and soft tissues may comprise human tissue
or other animal tissue. Other materials may include glass and
semiconductor chip surfaces, for example. The electromagnetically
induced cutting mechanism can be further used to cut or ablate
biological materials, ceramics, cements, polymers, porcelain, and
implantable materials and devices including metals, ceramics, and
polymers. The electromagnetically induced cutting mechanism can
also be used to cut or ablate surfaces of metals, plastics,
polymers, rubber, glass and crystalline materials, concrete, wood,
cloth, paper, leather, plants, and other man-made and naturally
occurring materials. Biological materials can include plaque,
tartar, a biological layer or film of organic consistency, a smear
layer, a polysaccharide layer, and a plaque layer. A smear layer
may comprise fragmented biological material, including proteins,
and may include living or decayed items, or combinations thereof. A
polysaccharide layer will often comprise a colloidal suspension of
food residue and saliva. Plaque refers to a film including food and
saliva, which often traps and harbors bacteria therein. These
layers or films may be disposed on teeth, other biological
surfaces, and nonbiological surfaces. Metals can include, for
example, aluminum, copper, and iron.
[0056] A user may adjust the combination of atomized fluid
particles exiting the nozzle 71 to efficiently implement cooling
and cleaning of the fiber optic guide 23 (FIG. 4a), as well.
According to an implementation of the present invention, the
combination of atomized fluid particles may comprise a
distribution, velocity, and mean diameter to effectively cool the
fiber optic guide 23, while simultaneously keeping the fiber optic
guide 23 clean of particular debris which may be introduced thereon
by the surgical site.
[0057] Looking again at FIG. 8, electromagnetic energy contacts
each atomized fluid particle 101 on its illuminated side 103 and
penetrates the atomized fluid particle to a certain depth. The
focused electromagnetic energy is absorbed by the fluid, inducing
explosive vaporization of the atomized fluid particle 101.
[0058] The diameters of the atomized fluid particles can be less
than, almost equal to, or greater than the wavelength of the
incident electromagnetic energy. In each of these three cases, a
different interaction occurs between the electromagnetic energy and
the atomized fluid particle. When the atomized fluid particle
diameter is less than the wavelength of the electromagnetic energy
(d<.lambda.), the complete volume of fluid inside of the fluid
particle 101 absorbs the laser energy, inducing explosive
vaporization. The fluid particle 101 explodes, ejecting its
contents radially. As a result of this interaction, radial
pressure-waves from the explosion are created and projected in the
direction of propagation. The resulting portions from the explosion
of the water particle 101, and the pressure-wave, may in some
embodiments operate at least in part to produce the "chipping away"
effect of cutting and removing of materials from the target surface
107. When the fluid particle 101 has a diameter, which is
approximately equal to the wavelength of the electromagnetic energy
(ds), the laser energy travels through the fluid particle 101
before becoming absorbed by the fluid therein. Once absorbed, the
distal side (laser energy exit side) of the fluid particle heats
up, and explosive vaporization occurs. In this case, internal
particle fluid is violently ejected through the fluid particle's
distal side, and moves rapidly with the explosive pressure-wave
toward the target surface. The laser energy is able to penetrate
the fluid particle 101 and to be absorbed within a depth close to
the size of the particle's diameter. When the diameter of the fluid
particle is larger than the wavelength of the electromagnetic
energy (d>.lambda.), the laser energy penetrates the fluid
particle 101 only a small distance through the illuminated surface
103 and causes this illuminated surface 103 to vaporize. The
vaporization of the illuminated surface 103 tends to propel the
remaining portion of the fluid particle 101 toward the targeted
material surface 107. Thus, a portion of the mass of the initial
fluid particle 101 is converted into kinetic energy, to thereby
propel the remaining portion of the fluid particle 101 toward the
target surface with a high kinetic energy. This high kinetic energy
is additive to the initial kinetic energy of the fluid particle
101. The effects can be visualized as a micro-hydro rocket with a
jet tail, which helps propel the particle with high velocity toward
the target surface 107. The electromagnetically induced cutter of
the present invention can generate a high resolution cut. Unlike
the cut of some prior art devices, the cut of the present invention
can be clean and precise. Among other advantages, this cut can
provide an ideal bonding surface, can be accurate, and may not
stress remaining materials surrounding the cut.
[0059] FIGS. 9 and 14 illustrate an embodiment of a tissue remover
110 which utilizes an electromagnetically induced cutter in
accordance with the present invention. The tissue remover 110
includes an aspiration cannula 112 having soft tissue aspiration
inlet port 120 adjacent to the distal end 114 and cannula tip 118
in the configuration presented in FIGS. 9a and 10a. As illustrated
in FIGS. 9a and 10a the cannula tip 118 can advantageously be a
generally rounded, blunt or bullet shaped tip attached to the
cannula 112 by welding or soldering. In FIGS. 9b and 10b, the
tissue remover 110 is configured to have an open cannula
configuration. As illustrated in FIG. 9, the cannula proximal end
116 is retained within the distal handle end cap 124, the aspirated
soft tissue outlet port 128 is retained within the proximal handle
end cap 126, and the distal handle end cap 124 and proximal handle
end cap 126 are retained within the handle 122. The soft tissue
outlet port 128 is connected to an aspiration source by a plastic
tubing (not shown).
[0060] As illustrated in FIGS. 9-13, a fluid and laser fiber guide
tube extends longitudinally within the tissue remover 110 from the
proximal handle end cap 126, at the laser and fluid source port
141, terminating at a point 140 (FIG. 10) immediately proximal to
the soft tissue aspiration inlet port 120 in the embodiment shown
in FIG. 10a. In FIG. 10b, the laser and fluid source port 161
terminates at point 140 adjacent to the interaction zone 159. The
fluid and laser fiber guide tube 136 resides partially within a
coaxial fluid channel 130 (FIG. 12) drilled in the proximal handle
end cap 126, and comprises a large fluid and laser fiber guide tube
132, a guide tube transition coupler 134, and a small fluid and
laser fiber guide tube 136. The guide tube transition coupler 134
is positioned within the handle 122 proximal to the proximal end of
the cannula 116 and is drilled to accommodate the external
diameters of the large 132 and small guide tubes 136. The guide
tube components are joined together and to the proximal handle end
cap 126 and within the aspiration cannula inner wall utilizing a
means such as soldering or welding. The fluid and laser guide tube
can be provided with an O-ring seal 146 (FIG. 12) at its retention
within the proximal handle end cap 126 at the laser energy source
port 141. The optional guide tube transition coupler 134 can be
used to provide for a small fluid and laser fiber guide tube 136
having a relatively small diameter. The optional guide tube
transition coupler 134 also allows for more space within the
aspiration cannula 112.
[0061] Housed within the fluid and laser fiber guide tube is the
laser fiber optic delivery system. As shown in FIG. 11, the laser
fiber optic delivery system comprises a fiber optic guide 123, an
air tube 163 and a water tube 165. The fiber optic guide 123, air
tube 163 and water tube 165 may be similar to the fiber optic guide
23, air tube 63 and water tube 65 described above with reference to
FIG. 4a. The water tube 165 can be connected to a saline fluid
source and pump, and the air tube can be connected to a pressurized
source of air. The air tube 163 and the water tube 165 are
terminated with a nozzle 171 which may be similar to the nozzle 171
described above with reference to FIG. 4a. In one embodiment, the
fiber optic guide 123, air tube 163, and water tube 165 operate
together to generate electromagnetically induced cutting forces. In
another embodiment, there is only a water tube 165, and no air
tube, connected to the nozzle 171. In this case, the nozzle 171 is
a water-only type of nozzle. Any of the above-described
configurations may be implemented to generate such forces, in
modified embodiments.
[0062] In an embodiment wherein the fluid emitted from the water
tube is water-based and the electromagnetic energy from the fiber
optic guide 123 is highly absorbed by the water, it may in some
instances be desirable to have a relatively non-aqueous environment
(wherein body fluids are minimized) between the output end of the
fiber optic guide 123 and the target surface. It may also be
desirable in certain embodiments to maintain a non-aqueous
environment between the nozzle 171 and the interaction zone 159
(FIG. 11) for generation of the atomized distributions of fluid
particles. An aspect of the present invention involves keeping body
fluids clear from the nozzle 171 and the interaction zone 159
enhances performance. Accordingly, means for reducing bleeding may
be desired in certain implementations. In this connection, the
distal blade of the cannula tip 118 can comprise a radio frequency
(RF) cutting wire. Electrosurgery procedures using RF cutting wires
implement high frequency (radio frequency) energy for implementing
cutting of soft tissue and various forms of coagulation.
[0063] In electrosurgery, the high density of the RF current
applied by the active electrosurgical electrode causes a cutting
action, provided the electrode has a small surface (wire, needle,
lancet, scalpel). Additionally the current waveform is a
significant factor in the cutting performance. A smooth,
non-modulated current is more suitable for scalpel-like cutting,
whereas the modulated current gives cuts with predetermined
coagulation. The output intensity selected, as well as the output
impedance of the generator, are also important with respect to
cutting performance. The electrosurgical cutting electrode can be a
fine micro-needle, a lancet, a knife, a wire or band loop, a snare,
or even an energized scalpel or scissors. Depending on (1) the
shape of the electrode, (2) the frequency and wave modulation, (3)
the peak-to-peak voltage, and (4) the current and output impedance
of the generator, the cut can be smooth, with absolutely no arcing,
or it can be charring and burn the tissue. Electrosurgical
coagulation may be carried out, for example, by implementing light
charring and burning in a spray coagulation mode. The biological
effect, accordingly, can significantly differ from gentle tissue
dehydration to burning, charring and even carbonization. The
temperature differences during the various coagulation process may
vary between 100 degrees Celsius to well over 500 degrees Celsius.
The means should be chosen in accordance with the amount of cutting
and/or coagulation that is desired, which will be a function of
various parameters such as the type of tissue being cut. In
accordance with an object of the present invention of reducing
smoke, bipolar applications or cutting with no-modulated current
may be implemented.
[0064] Pressurized air, N.sub.2 or O.sub.2 can be output from the
air tube 163 at various flow rates and various intervals, either
during cutting or between cutting, in order to provide a relatively
non-aqueous working environment for the electromagnetically induced
cutting forces. Insufflation procedures, for example, for
generating air cavities in the vicinity of the target tissue to be
cut and removed can be used to attenuate the introduction of
unwanted body liquids in the interaction zone 159.
[0065] The negative pressure generated and transmitted by the
flexible suction tubing may serve to evacuate from the interaction
zone 159 body fluids, removed tissue, and air and water from the
nozzle 171. As presently embodied, the large fluid and laser fiber
guide tube 132 is connected to a source of air and the negative
pressure generated and transmitted by the flexible suction tubing
serves to draw the air through the large fluid and laser fiber
guide tube 132 and the small fluid and laser fiber guide tube 136.
The source of air coupled to the large fluid and laser fiber guide
tube 132 may comprise moist air. The flow of air out of the small
fluid and laser fiber guide tube 136 serves to keep the nozzle 171,
the output end 140 of the fiber optic guide 123, and the
interaction zone 159 relatively free of body fluids. If additional
removal of body fluids is desired, one or more pressurized air
lines can be routed to distal end 114 of the cannula 114 adjacent
to the cannula tip 118. The pressurized air line or lines can be
activated to introduce air into the lumen of the cannula at the
distal end of the cannula to thereby facilitate the removal of body
fluids and water from the lumen. Effective removal of body fluids
and water from the distal end of the cannula, including the
interaction zone 159 and the portion of the lumen distal of the
aspiration inlet port, occurs when fatty tissue within the
aspiration inlet port forms a seal within the lumen of the cannula
so any body fluids are drawn out to the cannula lumen by the
negative pressure. The pressurized air line of lines provide
displacement for the fluids as they are removed. If the body fluids
are viscous, then water from the water tube 165 can be introduced
to attenuate the viscosity of and accelerate the removal of the
body fluids.
[0066] In accordance with certain embodiments only water or saline
is delivered to the nozzle 171 during cutting. In other
embodiments, the liquid delivered to the nozzle 171 carries
different medications such as anesthetics, epinephrines, etc. The
anesthetic may comprise, for example, lydocaine. The use of
anesthetics and vessel constrictors, such as epinephrines, may help
to provide anesthesia during and after surgery, and to reduce blood
loss. One or more controls disposed proximally of the aspirated
soft tissue outlet port 120 can allow the user to adjust the
percent of air and/or water that is directed to the nozzle 171 at
any given time. A control panel, having one or more of the features
of the control panel 77 shown in FIG. 5, can be used to control,
among other things, whether water alone, air alone, a combination
of air and water, or a combination of air and medicated liquid is
supplied to the nozzle 171.
[0067] The large guide tube 132 is maintained in position within
cannula 112, for example, by silver solder through holes 137, as
illustrated in FIGS. 10 and 11. The retention of the laser fiber
optic delivery system is accomplished by a retaining screw 142 at
the fluid, air and laser energy source port 141. As will be
apparent to those skilled in this art, a shorter and thinner soft
tissue aspiration cannula 112 will be useful in more restricted
areas of the body, as under the chin, and a longer and larger
diameter cannula will be useful in areas such as the thighs and
buttocks where the cannula may be extended into soft tissue over a
more extensive area. The cannula can be either rigid or flexible
depending on the type of access necessary to reach the surgical
site.
[0068] To perform the method of the present invention as
illustrated in FIG. 14, the surgeon determines the location and
extent of soft tissue to be removed. The appropriate size tissue
remover 110 is selected. A short incision is made and the cannula
tip 118 and the distal end of the cannula 114 are passed into the
soft tissue to be removed. Air and sterile water/saline are
delivered through the air and water tubes 163 and 165. The saline
may help to facilitate the removal of fatty tissues. The aspiration
pump is then activated. The resultant negative pressure thus
generated is transmitted to the tissue remover 110 via a flexible
suction tubing, to the soft tissue outlet port 128, through the
handle 122, through the cannula 112, to the soft tissue aspiration
inlet port 120. The resultant negative pressure at the inlet port
draws a small portion of the soft tissue into the lumen of the
cannula 112, into close proximity with the interaction zone 159
(FIG. 11a), or into the interaction zone 159 only when the cannula
does not include an inlet port 120 such as the cannulas shown in
FIGS. 9b, 10b and 11b. In the embodiment of FIGS. 9b, 10b and 11b,
negative pressure may not be required, wherein the cannula 112 is
advanced to close proximity of the target surface to be cut. The
edges of the cannula 112 distal end can be generally rounded or
bullet-shaped to facilitate insertion into the patient's tissue
with a minimum of localized tissue trauma. The nozzle 171 and the
output end of the fiber optic guide 123 may be disposed in a
slightly proximal location, relative to the configuration shown in
FIG. 11b, so that the output end of the fiber optic guide 123 is
proximal of the distal end of the small fluid and laser fiber guide
tube 136. Once the target tissue is positioned just distally of the
interaction zone 159, the laser is activated and
electromagnetically induced cutting forces are imparted onto the
soft tissue within the cannula lumen, cleaving the soft tissue.
Additional soft tissue enters the soft tissue aspiration inlet port
120 by virtue of a reciprocating longitudinal motion of the tissue
remover 110 within the soft tissue. This reciprocating motion is
applied by the surgeon's hand on the handle 122. The reciprocating
motion of the tissue remover 110, with respect to the surrounding
soft tissue, is facilitated by the stabilization of the soft tissue
by the surgeon's other hand placed on the skin overlying the
cannula soft tissue aspiration inlet port 120. Soft tissue that is
cut or ablated near the interaction zone 159 is drawn and removed
to the more proximal portion of the lumen of the cannula, and
eventually out the cannula to the soft tissue outlet port 128 by
the negative pressure generated by the aspiration pump.
[0069] Depending on the type of cannula or catheter used for the
procedure, endoscopes for providing an image of the surgical site
can be classified in three categories. Category 1 endoscopes
include rigid scopes using a series of rigid rods coupled to the
objective to capture the image of the targeted tissue. The rigid
scopes provide the best image quality with limited maneuverability.
Category 2 endoscopes include flexible scopes using optical fiber
bundles of up to ten thousand fibers in a bundle to capture the
image from the objective lens to the camera. Their final image is a
mosaic of the images gathered by each fiber in the bundle, and this
image has lower resolution than the image resulted from the rigid
scope. Surgical procedures inside tiny ducts, capillaries or
locations within the body that do not allow for direct/straight
access are examples of applications where flexible scopes are
needed. Category 3 endoscopes include semi-rigid scopes that use
optical fibers with limited flexibility. Through technological
advancements of the imaging devices, new technologies have emerged,
and some of them are still under development. An example of such an
advancement is infrared imaging technology. The infrared imaging
technology is based on a process of mapping temperature differences
at the surgical site by detecting electromagnetic radiation from
tissue that is at different temperatures from its surroundings.
Based on this type of information, this imaging technology can
provide the surgeon with more than just image information and data.
For example, a medical condition of the treatment site can be
established through such advanced imaging technology. All of the
above imaging technologies can be implemented with the
electromagnetic cutting device in accordance with the present
invention in helping the clinician to monitor and visualize the
surgical site during the procedure of cutting or removing tissue
with electromagnetically induced cutter.
[0070] The soft tissue aspiration cannula 112, cannula tip 118,
handle 122, distal handle end cap 124, proximal handle end cap 126,
aspirated soft tissue outlet port 128, large fluid and laser fiber
guide tube 132, guide transition coupler 134, small fluid and laser
fiber guide tube 136, and retaining screw 142 can be formed, for
example, of stainless steel. In modified embodiments, some or all
of the components can comprise medical grade plastics. In a
flexible cannula design, the cannula 112 is made out of a
biocompatible or medical grade flexible plastic. In a modified
embodiment, a disposable cannula, flexible or rigid, is constructed
from a medical grade disposable plastic. As will be apparent to
those of skill in this art, a shorter and thinner diameter
aspiration cannula will be useful in more restricted areas of the
body, as around small appendages, and a longer and larger diameter
cannula will be useful in areas, such as the thighs and buttocks,
where the cannula may be extended into fatty tissue over a more
extensive area. The cannula tip 118 is in sizes of the same
diameter as the aspiration cannula O.D., machined to a blunt tip
and to fit the cannula inside diameter. The handle 122 can be
formed of tubing. The distal handle end cap 124 can be machined to
fit the handle inside diameter and drilled to accommodate the
aspiration cannula outside diameter. The proximal handle end cap
126 can be machined to fit the handle inside diameter, drilled to
accommodate the aspiration outlet port, fluid and laser guide
channel, and large guide tube, and drilled and tapped to
accommodate the retaining screw. The aspirated soft tissue outlet
port 128 is preferably machined to fit the proximal handle end cap
and tapered to accommodate appropriate suction tubing. The guide
tube transition coupler 134 is preferably drilled to accommodate
large and small guide tubes 132 and 136. The small fluid and laser
fiber guide tube is determined by the length of the cannula
112.
[0071] By utilizing the present tissue remover 110 according to the
method described above, a variety of advantages are achieved. By
enabling the cutting of the soft tissue in a straight line, the
scooping, ripping and tearing action characteristic of prior-art
devices, is attenuated, resulting in fewer contour irregularities
and enhanced satisfaction. With the addition of the cutting action
of the present invention the rate of removal of unwanted soft
tissue can be enhanced over that of previous devices and techniques
thus decreasing operative time. Benefits may be obtained without
fear of peripheral laser thermal damage.
[0072] In a method in which the tissue remover is used to remove
hard tissue, such as bone or cartilage, the tissue remover may be
able to facilitate removal of the tissue with attenuated or
eliminated thermal damage. For example, in reference to knee
arthroscopy, a surgeon will typically create one or more incisions
near the knee in an anesthetized patient in need of arthroscopic
surgery. The patient may either be under general anesthesia or may
have been administered a local anesthetic or analgesic. The surgeon
then may insert a needle through the capsule of the knee joint and
fill the joint space with a fluid, such as normal saline, to help
facilitate distension of the knee to provide improved passage of
instruments and visualization of anatomical structures. A camera
may then be inserted into the existing incision, or into another
incision created by the surgeon, to permit camera-assisted
visualization of the knee anatomy. The tissue remover, as disclosed
herein, may then be inserted into one of the existing incisions, or
into a third incision created by the surgeon. The tissue remover is
used to remove bone, cartilage, or other hard tissue in connection
with the corrective surgery.
[0073] The knee replacement surgery may be performed by removing
the damaged tissue from the knee, and inserting prosthetic devices
where the damage tissue has been removed. In one particular
embodiment, the surgeon may use the tissue remover to remove part
of the damaged femur and the meniscus to expose the top surface of
the tibia. The tissue remover may then be used to remove damaged
tibia bone. A void is created within the tibia bone to receive an
adhesive that will provide adhesion between the tibia and the tibia
prosthetic implant. In the embodiment disclosed herein, the void
may be about 3 mm deep and about 2-3 cm in radius; however, other
dimensions may be used depending on the type of implant being used,
and the extent of the damage to the knee. Adhesive, such as bone
cement, is added to the void, and the tibia prosthetic is placed in
contact with the adhesive in a position complementary to the femur.
The prosthetic can be made from any suitable material as understood
by persons skilled in the art, examples of some materials include
polyethylene plastics or metals including metal alloys. Damaged
tissue from the femur, such as the femur condyle, is then removed
with the tissue cutter to create an opening to provide an
attachment site for the femoral prosthetic. Adhesive is applied to
the femur, and the femur prosthetic is attached. After the
procedure, the surgical site is flushed with saline to remove any
unwanted debris that may cause damage or irritation to the knee.
The instruments are removed, and the incisions are closed. The knee
is then tested by extending and flexing the joint. The tissue
removal can be performed by scanning the laser of the tissue
remover either manually or automatically using computer-assisted
devices.
[0074] Thus, the hard tissue removal using the tissue remover
described herein may be accomplished by removing the tissue without
directly contacting the tissue. This methodology thus may provide
the advantage of reducing one or more of thermal destruction and
secondary necrotic effects caused by thermal destruction to the
tissue. The tissue remover may in some embodiments causes a least
parts of the target surface to break apart, which may then be
aspirated from the surgical site. In one specific embodiment, the
tissue remover removes the hard tissue with the energy transferred
from the electromagnetic energy interacting with the spray from the
tissue remover, as herein disclosed. Although the procedure
described hereinabove is for knee replacement surgery, other
surgeries using the tissue remover disclosed herein include, and
are not limited to, removal and repair of torn cartilage, ligament
reconstruction, removal of loose debris.
[0075] In an arthroscopic procedure such as a menisectomy, for
example, the cannula 112 has no cannula tip 118 and the tip of the
fiber optic guide 123 is placed adjacent to the interaction zone
159 in the vicinity of the tissue target. The nozzle spray 171
delivers sterile water or saline to the interaction zone 159 and
the process of cutting the miniscule cartilage in the knee is the
same as described above and in the summary of the invention.
Specifically, upon absorption of the electromagnetic energy, the
atomized fluid particles within the interaction zone expand and
impart cutting forces onto the minuscule cartilage tissue. The
cartilage is then removed through this process and any tissue
debris, together with the residual fluid, is quickly aspirated
through the suction tube within the cannula. The same cannula
device described for this procedure and presented in FIGS. 9b, 10b
and 11b is used for neuroendoscopic and laparoscopic procedures.
The procedures related to these applications follow the same steps
as the procedure described for the removal of fatty tissues with
the electromagnetic tissue remover, or the steps regarding the knee
replacement surgery. In all of these applications, the cannula 112
can include an additional tube that contains an imaging device
required to visualize the surgical site during the procedure. FIG.
11c is a block diagram illustrating such an additional tube 136a
and imaging device 136b within the cannula 112. The imager can also
be provided through a separate cannula inserted through a different
opening into the patient's treatment surgical site.
[0076] In accordance with the present invention, water from the
water tube 165 can be conditioned with various additives. These
additives may include procoagulants and anesthetics, for example.
Other additives may be used, such as other medications. Co-pending
U.S. application Ser. No. 08/995,241 filed on Dec. 17, 1997 and
entitled FLUID CONDITIONING SYSTEM, which is a continuation of U.S.
application Ser. No. 08/575,775, filed on Dec. 20, 1995 and
entitled FLUID CONDITIONING SYSTEM which issued into U.S. Pat. No.
5,785,521, discloses various types of conditioned fluids that can
be used with the electromagnetically induced cutter of the present
invention in the context of soft tissue removal. Other additives
can include solubilizing and emulsifying agents in modified
embodiments when an object to be pursued is to solubilize and
emulsify the fatty tissue being removed. All of the additives
should preferably be biocompatible.
[0077] Although an exemplary embodiment of the invention has been
shown and described, many changes, modifications and substitutions
may be made by one having ordinary skill in the art without
necessarily departing from the spirit and scope of this
invention.
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