U.S. patent number 4,517,974 [Application Number 06/437,289] was granted by the patent office on 1985-05-21 for disposable hand piece for surgical lasers.
This patent grant is currently assigned to HGM, Inc.. Invention is credited to Howard M. C. Tanner.
United States Patent |
4,517,974 |
Tanner |
May 21, 1985 |
Disposable hand piece for surgical lasers
Abstract
A disposable hand piece for attachment at the end of a laser
catheter assembly. The hand piece is longitudinally tapered and is
generally wedge-shaped in its width so as to form a tool which can
be comfortable grasped by a surgeon for purposes of more accurately
controlling the laser beam applied through the laser catheter. The
hand piece includes an internal switching mechanism which may be
conveniently activated by pressing flexible panels positioned on
the sides of the hand piece. The hand piece is constructed of
inexpensive plastic materials and is designed to be disposable
after a single use.
Inventors: |
Tanner; Howard M. C. (Salt Lake
City, UT) |
Assignee: |
HGM, Inc. (Salt Lake City,
UT)
|
Family
ID: |
23735836 |
Appl.
No.: |
06/437,289 |
Filed: |
October 28, 1982 |
Current U.S.
Class: |
606/16 |
Current CPC
Class: |
A61B
18/22 (20130101); A61B 2018/225 (20130101); A61B
2018/202 (20130101) |
Current International
Class: |
A61B
18/22 (20060101); A61B 18/20 (20060101); A61B
017/36 () |
Field of
Search: |
;128/303.1,395-398,303.13,303.14,303.17-303.19 ;372/6,108
;219/121L,121LP |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
WO82/02488 |
|
Aug 1982 |
|
WO |
|
858852 |
|
Sep 1981 |
|
SU |
|
Primary Examiner: Coven; Edward M.
Attorney, Agent or Firm: Olive; B. B.
Claims
What is claimed and desired to be secured by United States Letters
Patent is:
1. A disposable hand piece for controlling and directing the
application of a laser beam produced by a laser powered by an
electrical power source and transmitted through an optical fiber
connected to said laser and encased in a sheath, comprising:
(a) an elongated body having a leading end and a trailing end,
comprising:
(i) a plastic molded top portion having a pair of opposed
resiliently outwardly biased side panels at the leading end
thereof;
(ii) a plastic molded bottom portion having a pair of notches
formed in opposed sides thereof for receiving said side panels,
said top portion being shaped to nest in said bottom portion behind
the leading end thereof;
(iii) said top and bottom portions being secured together to form
said body and providing:
(aa) a bore extending through said body, said optical fiber encased
by said sheath being mounted in said bore;
(bb) a cavity within said body intermediate the length thereof;
and
(cc) in a leading portion of said bottom portion forward of said
cavity, means anchoring the leading end of said optical fiber
encased by said sheath; and
(b) a pressure-sensitive switch mounted in said cavity between said
panels and including electrical contacts positioned for being
actuated by depressing either of said panels inwardly while holding
said hand piece; and
(c) electrical leads extending from said switch through said sheath
encasing said optical fiber and branching from said sheath to said
power source enabling said laser beam to be switched on and off by
means of depressing either of said panels to actuate said switch
while holding said hand piece.
2. A disposable hand piece as claimed in claim 1 wherein:
(a) said bore is downwardly sloped toward said trailing end to
cause said sheath with said encased optical fiber to drape
downwardly from the trailing end of said hand piece body; and
(b) as viewed in both elevation and plan, said body is shaped to
taper from said trailing to said leading end.
Description
BACKGROUND
1. The Field of the Invention
The present invention relates to surgical lasers and, more
particularly, to a disposable hand piece which carries the optical
fiber and electrical switching element of a surgical laser.
2. The Prior Art
Although the theory behind lasers was first described by Einstein
in the early 1900s, it was not until several decades later that
significant breakthroughs were made in their development. Early
lasers utilized solid crystalline rods constructed, for example,
from ruby. Such lasers were generally only capable of giving short
bursts of light. In about 1958, scientists developed a process
whereby laser light could be obtained by exciting various gases
within a tube. This was a significant breakthrough since it meant
that a continuous laser beam could be produced.
The advent of the laser has opened new frontiers to many areas of
science and has revolutionized many procedures. One of the most
important of these new frontiers has been the application of laser
technology to various procedures in the field of medicine. The
first significant medical use of a laser occurred in 1965 when
doctors utilized an argon laser to repair a detached retina. The
doctors were able to focus the laser into the interior portion of
an eyeball and "weld" the detached retina back into place. Since
that time, different types of lasers have been developed and
applied to numerous surgical procedures.
For purposes of surgery, lasers operate on the principle that the
highly collimated laser light beam may be converted into thermal
energy when focused upon tissue. Because lasers can be focused onto
very small areas, it is possible to be extremely precise during
certain operations and to treat specific pathologies without
affecting surrounding tissue. Each type of laser produces a light
beam having a specific and unique wave length. Inasmuch as
different wave lengths of light are absorbed, reflected, scattered,
or transmitted by tissue to varying degrees, each type of laser has
been found to have unique applications.
For example, argon lasers produce a visible blue-green light having
a wavelength in the 488 to 514 nanometer range. This light is
easily transmitted through clear aqueous tissues such as the
cornea, lens and vitreous humor of the eye. On the other hand,
certain tissue pigments such as melanin and hemoglobin absorb this
light very effectively. Therefore, argon lasers have proven to be
very effective in treating pigmented lesions such as port-wine
hemangiomas. The laser light passes through the skin surface
without being absorbed significantly until it reaches the pigmented
layer where it is almost totally absorbed, causing heat generation
and protein coagulation.
The argon laser can also effectively be utilized as a scalpel. By
focusing the laser to a narrow beam or by increasing its intensity,
the power density can be increased to a strength sufficient to
vaporize the target tissue, thus allowing incisions to be made.
Additionally, because the argon-produced light is readily absorbed
by hemoglobin, severed blood vessels are coagulated simultaneously
with the formation of the incision.
A second type of laser which has found significant use in the
medical field is the carbon dioxide (CO.sub.2) laser. The CO.sub.2
laser produces invisible infrared light with a wave length of about
10,600 nanometers. This light is entirely absorbed by the water
present in body tissues within about 100 microns of the point of
impact. However, because of this efficient absorption, CO.sub.2
lasers make effective scalpels but must be used in dry,
non-bleeding areas to prevent the energy from being dispersed.
Because the CO.sub.2 light beam is so readily absorbed, it cannot
be used when it is necessary to transmit the light through various
layers of tissue to reach the pathology.
Other types of lasers which have been utilized in surgical
procedures include the neodymium yttrium aluminum garnet (Nd-YAG)
and xenon lasers. Each of these lasers also has its preferred
applications.
Some laser beams such as those of the argon, Nd-YAG, and xenon
lasers can be transmitted through optical fibers to the point of
application. On the other hand, because the CO.sub.2 laser has a
relatively large wavelength, it cannot be transmitted through these
optical fibers but must be directed through multi-jointed arms
containing lenses and mirrors, and is thus limited to line of sight
operations. Additionally, the multi-jointed arms with their
accompanying lenses and mirrors are complicated and expensive to
construct. Accordingly, argon type lasers are more convenient to
use and they have found a wide variety of applications in the
medical field.
The optical fiber (typically quartz) used to transmit an argon-type
laser beam may be extremely small, generally ranging from about 0.1
to about 0.6 millimeters in diameter, and is quite fragile.
Accordingly, the fiber is usually encased within a silicon sheath
and is then placed within some type of protective plastic tubing.
The entire assembly is sometimes referred to as a "laser
catheter."
In the past, it has been common practice for surgeons to simply
grasp the protective tubing when using an argon type laser in
surgical procedures. This may create some difficulties because the
tube is very flexible and long, and is thus difficult to control
with a high degree of precision. Moreover, because the optical
fiber is sometimes very small, the overall protective tubing may
also be correspondingly small in size and thus, difficult to grasp
near the tip when attempting to position the tip of the optical
fiber with precision.
Another common problem in the state of the art is that argon type
medical lasers typically do not have a convenient means for
switching the laser on and off. A small amount of light is
generally constantly transmitted through the optical fiber for
purposes of assisting the surgeon to accurately aim the laser beam.
However, because of the extreme power of the laser beam, it is
imperative that full power only be applied at the precise instant
that the surgeon desires to perform the surgical procedure.
Normally, full laser power is controlled by a foot switch connected
to the laser source.
The use of a foot switch for purposes of turning the laser beam on
and off gives rise to several disadvantages. First, the surgeon
must be very careful that he does not accidentally activate the
foot switch. Second, in many types of operations the surgeon will
be required to operate over substantial periods of time, which will
mean repeated activation and deactivation of the laser foot switch.
During this type of extended operation, the surgeon may become
extremely uncomfortable or fatigued by virtue of the fact that he
must constantly keep one foot resting on the foot switch, which
prevents him from putting his full weight on that foot. Obviously,
this may adversely affect the surgeon's balance, rendering his job
more difficult. Moreover, if the surgeon completely removes his
foot from the foot switch, the switch may become displaced and he
may have difficulty locating it once it is desired to again
activate the laser beam. This is especially disadvantageous should
the surgeon unexpectedly need to utilize the laser beam to
coagulate bleeding vessels. Finally, it is also difficult to
control the foot switch, especially when wearing shoes. Use of a
foot switch also renders it more difficult for the surgeon to
accurately place a laser beam and requires additional hand and foot
coordination, which greatly increases the difficulty of the
surgical procedure.
Accordingly, what is needed in the art is a hand piece which can be
attached to the end of a laser catheter assembly so as to provide
the surgeon with a convenient tool which he can easily grasp and
which he can more easily and more precisely use for purposes of
positioning the tip of the optical fiber, and which includes means
for activating or deactivating by hand the laser beam supplied
through the catheter assembly.
OBJECTS AND BRIEF SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a hand
piece which can be attached to the end of a laser catheter assembly
to facilitate handling.
It is a further object of this invention to provide a hand piece
which includes means for conveniently activating by hand the laser
source to which the laser catheter assembly is attached.
Another object of this invention is to provide a laser hand piece
which is sufficiently economical in its construction as to be
completely disposable after each use, thus eliminating the need for
time consuming and costly resterilization techniques.
These and other objects and features of the present invention will
become more fully apparent from the following description and
appended claims taken in conjunction with the accompanying
drawings.
In accordance with the foregoing objects, the present invention
provides a novel, disposable hand piece which can be attached to
the end of a laser catheter assembly to assist a surgeon in
directing and operating the laser.
In one preferred embodiment, the apparatus of the present invention
comprises an elongated hand piece having a generally tapered,
wedge-shaped configuration which is adapted to be comfortably held
in the hand in a pencil-like manner. A conduit is formed through
the length of the hand piece into which the laser catheter assembly
is positioned. A pair of electrical wires are inserted into the
laser catheter assembly and are attached to a membrane switch
positioned in the forward portion of the hand piece. The switch is
positioned between two flexible, resilient panels, each forming a
portion of the side of the hand piece. Thus, the hand piece can
comfortably be held in the surgeon's hand and the tip can be
directed to the point where the laser is to be applied. The surgeon
can then gently squeeze the flexible panels to activate the
laser.
Additionally, the laser hand piece includes an interchangeable
sleeve in the forward portion thereof. The sleeve is used to
securely anchor the end of the laser catheter assembly in the hand
piece. The sleeve may include a lens or collimator to increase the
focusing of the laser beam with greater precision.
The entire hand piece is designed to be easily and inexpensively
fabricated such that it can be disposed of together with the entire
laser catheter assembly after a single use.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is next made to the drawings, in which like parts are
designated with like numerals throughout, and in which:
FIG. 1 is a perspective view of a laser hand piece constructed in
accordance with the present invention;
FIG. 2 is an exploded perspective view of the laser hand piece of
FIG. 1;
FIG. 3 is an enlarged cross-sectional view of a first preferred
embodiment of the present invention taken along line 3--3 of FIG.
1;
FIG. 4 is an enlarged view of the front portion of the
cross-section encompassed by line 4--4 illustrated in FIG. 3;
FIG. 4a is an enlarged end-sectional view of the tip of the laser
catheter used in conjunction with the laser hand piece of the
present invention taken along lines 4A--4A of FIG. 1;
FIG. 5 is an enlarged cross-sectional view of the first preferred
embodiment of the laser hand piece of the present invention taken
along lines 5--5 of FIG. 1; and
FIG. 6 is an enlarged cross-sectional view of the front portion of
a second preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, a laser hand piece constructed according
to the present invention is generally designated at 10. As shown in
FIGS. 1 and 2, the laser hand piece 10 includes body portion 12 and
a cap portion 14 which are designed to to be snapped and bonded
together as hereinafter more fully described. The hand piece 10 is
generally tapered from the trailing end 16 up to the tip or leading
end 18. As illustrated in FIG. 2, in addition to the taper, the cap
portion 14 of hand piece 10 is also wedge-shaped and is thus also
tapered inwardly on the longitudinal sides 20 thereof. The body
portion 12 of hand piece 10 has a corresponding V-shaped channel 22
which is adapted to receive the wedge-shaped cap portion 14.
Longitudinal sides 20 of the cap portion 14 are also designed with
an inclining edge 24 which is supported by a corresponding inclined
shoulder 26 formed along the inside surface of the V-shaped channel
22.
As shown at the trailing end 16 of the cap portion 14, a groove 28
is formed along the underside of the cap portion 14 along its
entire length (see also FIG. 3) from one end thereof to the other.
A corresponding groove 30 (see FIG. 3) is also formed at the bottom
of the V-shaped channel 22 in the body 12 of the hand piece 10.
When the cap 14 and body 12 are joined together as in FIGS. 1 and
3, grooves 28 and 30 form a conduit through which a laser catheter
assembly generally designated at 32 enters the hand piece 10 at the
trailing end 16 thereof. As shown best in FIG. 3, the laser
catheter assembly 32 rests in the groove 28 formed in the underside
of cap portion 14 and projects into the bore 34 (see FIG. 2) which
is located through the front portion 36 of the body 12. As can be
seen, the front portion 36 of body 12 slopes upwardly so as to form
a pencil-like tip 18 at the forward portion of the hand piece
10.
With further reference to FIGS. 1 and 2, the cap portion 14 also
includes a pair of flexible panels 38 and 40 which extend
downwardly along the sides of the cap portion 14. As hereinafter
more fully described, the flexible panels 38 and 40 are designed so
as to be resilient and so as to be slightly biased outwardly so
that when the panels 38 and 40 are squeezed by the fingers, an
electrical switch will be activated which turns on the laser beam.
Each of the flexible panels 38 and 40 include a generally circular
indentation 42 on the face thereof. The indentations 42 are adapted
to comfortably receive the fingers so that the fingers may be
firmly positioned on the flexible panels 38 and 40, which form the
external switch mechanism or trigger of the laser hand piece
10.
Body 12 is provided with corresponding notches 44 and 46 along the
sides thereof which receive the flexible panels 38 and 40. Flexible
panels 38 and 40 are also provided with two small tabs 48 and 50
(see FIG. 2) and the leading end of the cap portion 14 is provided
with a similar tab 52. The tabs 48, 50 and 52 are designed to be
inserted along the inside edges of the notches 44, 46 and bore 34,
respectively. The tabs 48, 50 and 52 are thus used to snap the tip
and flexible panels 38 and 40 of cap portion 14 onto the body 12.
The rear of cap portion 14 may be glued or otherwise suitably
bonded to the inclined shoulder 26 and/or the sides of the V-shaped
channel 22 of body 12, so as to form a completely enclosed,
integral hand piece.
In the illustrated embodiment, cap portion 14 and body 12 of hand
piece 10 are constructed from high impact styrene which are formed
as molded components using conventional molding techniques. Of
course, other suitable materials could work equally as well.
As best illustrated in FIG. 4, the laser catheter assembly 32
includes an optical fiber 54 which forms the center of the laser
catheter 32. The optical fiber 54 is a 600 micron quartz fiber
having a bend radius of approximately 2 cm. The optical fiber 54 is
encased by silicon cladding 56 which enhances the optical
transmission properties of fiber 54 and which also forms a
protective sheath around the optical fiber 54 so that the fiber,
which is otherwise quite brittle, will be protected from damage. In
some cases, an additional layer (not shown) of Tefzel (TM) may also
be used to further strengthen the quartz fiber 54. The optical
fiber 54 and the silicon cladding 56 are typically referred to in
the art as "dressed optical fiber," which may be readily obtained
from a number of commercial manufacturers. For example, in the
illustrated embodiment the dressed optical fiber may be obtained
from Quartz Products Co. of Plainfield, N.J.
With continuing reference to FIG. 4, the dressed optical fiber
consisting of quartz fiber 54 and silicon cladding 56 is inserted
through a radially enlarged polyethylene conduit 58. The diameter
of conduit 58 is large enough so as to provide a space around the
dressed optical fiber, thus permitting a cooling gas such as carbon
dioxide to be forced through the conduit 58 and out the tip of the
laser hand piece. The carbon dioxide gas is used to cool the tip of
the optical fiber and is also used to disperse any vaporized tissue
that may tend to collect on the tip of the fiber.
As shown in FIG. 1, the laser catheter assembly 32 is attached at
one end 60 thereof to a laser (not shown) and to a source of
pressurized carbon dioxide gas (not shown). In the illustrated
embodiment the laser may be, for example, an argon ion type laser.
Other suitable kinds of lasers could also be used. The laser
catheter assembly 32 also includes a second conduit 62 which, as
hereinafter more fully described, carries a pair of electrical
wires which lead to the power supply (not shown) of the laser and
which are used to selectively activate or deactivate the laser beam
for purposes of the surgical procedure to be performed. The conduit
62 is joined to the laser catheter assembly 32 by means of a
conventional heat shrink wrap 64.
With reference again to FIG. 4, the other end of the laser catheter
assembly 32 terminates in a cylindrical sleeve 66 which is inserted
in the bore 34 at the tip 18 of body 12. The sleeve 66 is slightly
shorter in length than the bore 34, thus leaving a small space 68
at the end of bore 34 which is adapted to receive the tab 52 which
is used to help snap the cap portion 14 onto the body 12 of the
hand piece. As further illustrated in FIG. 4, the optical fiber 54
is bared at its leading end and projects into a collet 70 which is
inserted into the leading end of the conduit 58. As shown best in
the enlarged end-sectional view of FIG. 4a, collet 70 has a
plurality of slits 71 running from the back end thereof to a point
slightly beyond the tip of fiber 54 to allow the carbon dioxide gas
to pass therethrough and to exit near the bare tip of the fiber 54
for purposes of cooling as described above.
Reference is next made to FIGS. 3 and 5, which illustrate in
greater detail the switch mechanism of the laser hand piece.
Referring first to FIG. 3, the body 12 has an elongated, enlarged
channel 72 formed in the interior thereof. Elongated channel 72 is
adapted to receive the membrane switch generally designated at 74,
which is positioned inside of the body 12. Elongated channel 72 is
long enough to accommodate the electrical connections and wires 76
and 78 which are connected to the switch 74 and which are
introduced through the conduit 58 of the laser catheter assembly.
Wires 76 and 78 are inserted through a small hole 80 which may
thereafter be enclosed by a small globule of silicon (not shown) or
by a conventional heat shrink sleeve (not shown).
The switch 74 consists of a plastic membrane switch which may be
activated from either side of the laser hand piece by squeezing at
circular indentations 42 on the flexible panels 38 or 40. As shown
best in the sectional top view of FIG. 5, the flexible panels 38
and 40 each include on their inside surface a small, raised bump 82
and 84 which just barely contacts or is slightly separated from the
sides of the membrane switch 74. The membrane switch 74 consists of
two elongated pieces of plastic 85-86 which are bonded together and
which are folded around a rigid, upright post 88 formed at the
center and as an integral part of the interior of body 12. The
outer layer of plastic 86 is resilient and is formed with raised
domes 90 and 92 which have metal contacts 94 and 96 positioned on
the inside surface thereof. The metal contacts 94 and 96 are
designed to engage corresponding metal contacts 98 and 100 which
are positioned on the outside surface of the second layer of
plastic 85. Thus, when the indentations 42 of the flexible panels
38 or 40 are squeezed inwardly metal contacts 94 or 96 engage the
corresponding metal contacts 98 or 100, switching on the laser beam
by means of wires 76 and 78 which are connected to the laser power
supply (not shown).
As shown in FIG. 3, the contact pair 96 and 100 are connected by a
thin conductive strip 104 which in turn is connected to wire 78.
The contact pairs 94, 98 are likewise electrically connected
through a conductive strip 106 and through wire 102 to wire 78.
Wire 76 is connected through conductive strip 108 to both pairs of
contacts so that by making contact on either side of the hand piece
the laser beam can be activated. In the illustrated embodiment the
membrane switch may be manufactured using conventional technology,
and is available from Rogers Corporation of Tempe, Ariz.
Advantageously, by providing for activation of the laser beam on
either side of the laser hand piece, better control is accomplished
and the laser hand piece is much more convenient to use. The
tapered, wedge-shape of the hand piece also facilitates greater
accuracy and control of the laser beam because the hand piece is
designed to fit comfortably within the surgeon's hand in a
pencil-like fashion. Thus, less fatigue results over extended
periods of use using the hand piece of the present invention. Also,
since the trailing end 16 of the hand piece slopes inwardly and
also because the laser catheter 32 is directed on an incline, the
laser catheter slopes down and away so as to be out of the way of
the surgeon as the hand piece is used. The hand piece is very light
in weight and is easily constructed, further adding to its
convenience and also its very economical construction which
accommodates disposal after a single use.
Reference is next made to FIG. 6, which illustrates an additional
feature of the laser hand piece of the present invention. In FIG.
6, the body, cap and switching means are identical to that
previously described in connection with FIGS. 1-5. Only the
cylindrical insert sleeve positioned in the forward end of the
conduit 58 is different.
As shown in FIG. 6, the sleeve 86a has an enlarged bore 110 at the
forward end thereof. The enlarged bore 110 communicates with a
diameterally-reduced central bore 112 in which the bared, leading
end of optical fiber 54 is positioned. The central bore 112 in turn
communicates with a somewhat larger bore 114 through which the
optical fiber 54 and silicon cladding 56 extends. At the leading
end of the sleeve 86a a collimator in the form of a lens 116 is
positioned. In this particular embodiment, carbon dioxide or other
inert gas is not forced through the conduit 58 inasmuch as the
sleeve 86a is enclosed at its end by the lens 116. Lens 116 may be
desirable in applications where it is necessary to focus the laser
beam with greater precision.
In summary, from the foregoing description it will be appreciated
that the laser hand piece of the present invention is simple and
inexpensive to construct so that it may be readily disposed of
together with the laser catheter assembly after a single use.
Further, the design of the hand piece is such that it provides a
comfortable tool for the surgeon to work with. The laser hand piece
is much more convenient to operate because it permits the surgeon
to activate the laser by means of a simple hand movement applied at
the sides of the hand piece, as opposed to the prior state of the
art which employed a cumbersome and difficult to use foot
switch.
It should further be appreciated that while the present invention
has been particularly described in reference to the presently
preferred embodiments, the invention may be embodied in other
specific forms without departing from its spirit or essential
characteristics. Thus, the described embodiments are to be
considered in all respects only as illustrative and not
restrictive. The scope of the invention is, therefore, indicated by
the appended claims rather than by the foregoing description, and
all modifications or changes which come within the meaning and
range of equivalency of the claims are to be embraced within their
scope.
* * * * *