U.S. patent number 3,886,945 [Application Number 05/413,684] was granted by the patent office on 1975-06-03 for cryosurgical apparatus.
This patent grant is currently assigned to Frigitronics of Conn., Inc.. Invention is credited to Joseph F. Andera, Joseph G. Stumpf.
United States Patent |
3,886,945 |
Stumpf , et al. |
June 3, 1975 |
Cryosurgical apparatus
Abstract
There is disclosed a cryosurgical apparatus of the type which
operates from a source of compressed gas. It includes a handle
portion with removable and interchangeable probes. A defrost valve
in the exhaust conduit permits easy and quiet operation by the
surgeon. It is constructed in such a manner that the exhaust valve
cannot be closed unless the probe is fully seated in the handle. It
also includes an improved nozzle which is substantially less
critical than prior art nozzles and permits simplified and less
expensive construction. The foregoing abstract is not to be taken
either as a complete exposition or as a limitation of the present
invention. In order to understand the full nature and extent of the
technical disclosure of this application, reference must be had to
the following detailed description and the accompanying drawings as
well as to the claims.
Inventors: |
Stumpf; Joseph G. (Fairfield,
CT), Andera; Joseph F. (Trumbull, CT) |
Assignee: |
Frigitronics of Conn., Inc.
(Shelton, CT)
|
Family
ID: |
26949294 |
Appl.
No.: |
05/413,684 |
Filed: |
November 7, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
262543 |
Jun 14, 1972 |
3807403 |
|
|
|
Current U.S.
Class: |
606/26;
239/597 |
Current CPC
Class: |
A61B
18/02 (20130101); F25B 9/02 (20130101); A61F
7/12 (20130101); F25B 2309/021 (20130101); F25B
2309/022 (20130101) |
Current International
Class: |
A61B
18/00 (20060101); A61B 18/02 (20060101); A61F
7/12 (20060101); F25B 9/02 (20060101); A61b
017/36 (); B05b 001/00 () |
Field of
Search: |
;62/293 ;128/303.1
;239/597 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Pace; Channing L.
Attorney, Agent or Firm: Buckles and Bramblett
Parent Case Text
BACKGROUND OF THE INVENTION
This application is a continuation in part of our copending U.S.
Pat. Ser. No. 262,543, filed June 14, 1972 now U.S. Pat. No.
3,807,403, for "Cryosurgical Apparatus".
Claims
We claim:
1. A gas operated cryosurgical instrument which comprises: a handle
defining a socket therein; a movable first valve member in said
handle; a tubular exhaust conduit terminating at one end in a
hollow tip of high thermal conductivity, the other end defining a
second valve member and including means detachably securing said
exhaust conduit seated within said socket; a gas delivery conduit
mounted in said handle and extending through said socket and
through said exhaust conduit when so secured and terminating at a
nozzle within said tip; means for selectively advancing said first
valve member against said second valve member to close said exhaust
conduit when said exhaust conduit is fully seated within said
socket; and means for limiting the movement of said first valve
member to prevent closure of said exhaust conduit when the conduit
is not fully seated within said socket.
2. The instrument of claim 1 wherein said first valve member is
carried by said gas delivery conduit.
3. The instrument of claim 2 wherein said advancing means comprises
a manually operable trigger connected to advance both of said
delivery conduit and valve member.
4. The instrument of claim 1 wherein said first valve member
comprises a ball.
5. The instrument of claim 1 wherein said nozzle includes a
cylindrical gas discharge passage of smaller diameter than said
delivery conduit and a smoothly curved reduction passage
therebetween.
6. The instrument of claim 1 wherein said advancing means
comprises: pivot means within said handle; a rod supported by said
pivot means having a first end engaging said first valve member on
one side of said pivot means and a second end on the other side of
said means; and a manually operable trigger secured to the second
end of said rod.
7. The instrument of claim 6 wherein said pivot means comprises a
trunnion ball rotatably supported within said handle.
8. The instrument of claim 7 wherein said first valve member is
carried by said gas delivery conduit.
9. The instrument of claim 8 wherein said first valve member
comprises a ball.
10. The instrument of claim 9 wherein said nozzle includes a
cylindrical gas discharge passage of smaller diameter than said
delivery conduit and a smoothly curved reduction passage
therebetween.
Description
This invention pertains to cryosurgical instruments of the type
which are cooled under the influence of high pressure gas escaping
from an orifice. Instruments of this type are well known in the art
and are widely employed for a number of surgical procedures such as
the necrosis of diseased tissue. Several gases exhibit the
Joule-Thomson effect and may be used in the operation of the
instrument. The most common, however, are nitrous oxide and carbon
dioxide.
In instruments of this type, the gas expansion orifice is of an
extremely small size and in all prior art instruments the spacing
between the orifice and the inner wall of the cooling tip is
extremely critical. For example, with prior art instruments, the
orifice is positioned approximately 0.050 inch from the inner wall
of the tip and the permitted tolerance is only 0.010 inch. This
results in such instruments being difficult and costly to
manufacture. For example, the parts of such instruments are
commonly threaded so that they may be factory adjusted prior to
shipment.
Another problem connected with prior art instruments of this type
is found in the exhaust valve of instruments which have controlled
defrost. For example, one such instrument is normally warm, which
means that the exhaust valve is normally closed and the device is
filled with compressed gas at bottle pressure. As the bottle gas
pressure may commonly be as high as 800 psi, it will be quite
apparent that this creates an explosion hazard. The exhaust valve
used in this prior art device comprises a cylindrical piston which
seats against a small exhaust orifice and is retained in the seated
position by means of a heavy spring. The piston is raised against
the force of a spring by means of a finger operated toggle. When
the surgeon wishes to cool the probe tip, he must apply substantial
force to depress the toggle which is, itself, detrimental,
particularly in the case of very delicate surgical procedures.
Secondly, as soon as the piston begins to leave the orifice, the
full bottle pressure, which was formerly applied only to a small
area of the piston, is now applied to the full area of the piston
end, slamming the piston open with an explosive-like report.
Still another problem with prior art devices arises from the fact
that most of them are designed with probe tips of specific shapes
and sizes. This requires a surgeon to have different instruments
for different surgical applications. It has been proposed to
provide a single instrument with interchangeable probes. However
this creates a problem due to the high pressures referred to in the
preceding paragraph. If a probe were not fully seated, by
negligence or otherwise, or if it were not fully seated because of
a defect such as stripped threads, the high pressures involved
could result in the probe and tip being forcibly ejected during a
surgical procedure with potentially disastrous results.
Accordingly, it is a primary object of the present invention to
provide an improved cryosurgical instrument of the gas operated
type having replaceable and interchangeable probe tips. Another
object is to provide such an instrument wherein the exhaust valve
cannot be closed to pressurize the instrument unless the probe is
fully seated. Another object is to provide such an instrument which
is only intermittently exposed to full bottle gas pressure. Another
object is to provide such an instrument which has a substantially
silent and easily operated exhaust valve. The manner in which these
objects are achieved will be apparent from the following
description and appended claims.
SUMMARY OF THE INVENTION
The invention comprises a gas operated cryosurgical instrument
which comprises a handle and a movable first valve member in the
handle. A tubular exhaust conduit terminates at one end in a hollow
tip of high thermal conductivity. The other end defines a second
valve member and includes means for detachably securing the exhaust
conduit to the handle. A gas delivery conduit extends through the
exhaust conduit when it is so secured and terminates at a nozzle
within the tip. Means are provided for selectively advancing the
first valve member against the second valve member to close the
exhaust conduit. Means are also provided for limiting the movement
of the first valve member to prevent closure of the exhaust conduit
when it is improperly secured to the handle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a cryosurgical instrument in
accordance with the present invention connected to a source of
bottled gas;
FIG. 2 is an enlarged cross section taken through the instrument of
FIG. 1;
FIG. 3 is a cross section of the exhaust valve of FIG. 2 shown in
its closed position;
FIG. 4 is a greatly enlarged cross section of the nozzle portion of
the apparatus;
FIG. 5 is an illustration of the gas jet obtained with the nozzle
of FIG. 4;
FIG. 6 is a cross section taken substantially along the line 6--6
of FIG. 5;
FIG. 7 is an illustration of one type nozzle used in the prior
art;
FIG. 8 is a cross section taken substantially along the line 8--8
of FIG. 7;
FIG. 9 is an illustration of another type nozzle used in the prior
art;
FIG. 10 is an enlarged cross section showing the orifice of the
FIG. 9 nozzle; and
FIG. 11 shows still another type nozzle used in the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With particular reference to FIG. 1, there is disclosed an
instrument of the type utilized in treating cervicitis. It
comprises an elongated probe 10 mounted in a handle 12 and
terminating in a substantially conical hollow applicator tip 14. A
line 16 is connected between the instrument and a suitable source
18 of pressurized gas. A trigger 20 extends from the handle for
selective defrosting as will be explained.
Referring to FIG. 2, the handle 12 will be seen to define a recess
22 for the trigger 20 and a T-shaped recess 24 communicating
therewith and enclosing a metal T fitting 26. The horizontal
portion of fitting 26 has internal threads 28 and the lower end of
the vertical portion is provided with similar internal threads 30.
Within the vertical portion of the T fitting 26 and near its
juncture with the horizontal portion, there is defined an internal
shoulder 32. Mounted against the shoulder 32 is a resilient O-ring
34. Bearing against the O-ring 34 is a circular plastic sealing
ring 36. A trunnion ball 38 is mounted against the sealing ring 36.
The trunnion ball 38 is integral with an upper rod 40 and lower rod
42. The end of upper rod 40 includes a flattened portion 44 which
defines an opening 46 therein. Opening 46 is substantially coaxial
with the bore of the horizontal portion of T-fitting 26, as
illustrated in FIG. 2. The lower rod 42 extends into the recess 22
of handle 12 and the trigger 20 is secured to lower rod 42 by means
of a set screw 48. The trunnion ball assembly is retained within
the T-fitting by a lower plastic sealing ring 50 supporting the
trunnion ball 38, a compression spring 52, and an annular retainer
nut 54 threaded into the threads 30. A trigger return coil spring
56, supported within a bore 58 in trigger 20 and seated against the
back wall of recess 22, maintains the trigger in its normally
extended position as shown in FIG. 2.
The flexible gas delivery line 16 is connected by means of a
retainer ring 60 to the end of a stainless steel delivery tube 62
which extends forwardly outward of the handle and terminates at a
nozzle 64. The outer diameter of tube 62 is less than the diameter
of the opening 46 in the flattened portion 44 of upper rod 40. In
one embodiment, the delivery tube 62 is a 15 gauge stainless steel
hypodermic tube. The tube 62 passes through a ball 66 to which it
is integrally secured as by welding.
The probe tip 10 is a complete assembly which is detachable from
the handle portion of the instrument. It comprises a threaded
sleeve 68 which screws into the T-fitting 26 as shown. Fixedly
secured to the sleeve 68, as by welding, is a stop ring 70. An
O-ring 72 provides a seal between stop ring 70 and the T-fitting
26. Fixedly secured to the inside of sleeve 68 is an exhaust
conduit 74 which surrounds, and is spaced from, delivery tube 62.
The distal end of exhaust conduit 74 carries a sleeve 76 to which
is secured the hollow tip 14. Surrounding and spaced from the
exhaust conduit 74 is an insulator tube 78, secured at one end to
the sleeve 76 and tip 14 and at the other to sleeve 68 and stop
ring 70. This tube is provided with a knurled finger grip 80. The
end of exhaust conduit 74 forms, with sleeve 68, a tapered valve
seat 82.
The construction of nozzle 64 will be best understood by reference
to FIG. 4. As will be seen therein, the internal diameter of the
delivery tube 62 is reduced via a smooth wall reduction passage 84
to a cylindrical gas discharge passage 86. This configuration is
achieved by inserting into the end of the hypodermic tube a
hardened wire having an external diameter equal to the desired
diameter of the gas discharge passage. The end of the tube is then
swaged onto the wire and the wire is removed. In one actual
embodiment, the tube 62 has an internal diameter of 0.059 inch and
the internal diameter of the gas discharge passage 86 is 0.01065
inch. The distance from the nozzle tip to the beginning of
reduction (A FIG. 4) is 0.20 inch and the distance between the
nozzle tip and the end reduction (B) is 0.12 inch.
The performance of the nozzle 64 is strikingly superior to those of
the prior art. The reason for this is not fully understood but is
believed to be due to the smooth continuous inner surface formed by
the reduction passage 84 and the gas discharge passage 86. This is
believed to prevent gas turbulence and permit laminar flow out of
nozzle 64. FIG. 5 illustrates the gas flow from nozzle 64 as
actually observed in practice. As will be seen, it presents an
elongated "flamelike" appearance and shape. FIGS. 7-11 illustrate
three prior art nozzle constructions and the jets obtained thereby.
FIGS. 7 and 8 illustrate a pinched tube configuration. FIGS. 9 and
10 illustrate a rolled end construction, and FIG. 11 illustrates a
type of orifice known as a "double reduction" orifice which
comprises a series of tubes of reduced diameter. The jets from
these prior art nozzles appear as indicated. In these prior art
nozzles, the distance from the orifice to the wall of the
applicator tip is very critical and the spacing must be quite
close. As an example, this distance may be 0.050 inch with a
tolerance of .+-. 0.010 inch. In contrast, in utilizing the nozzle
of this invention, the distance from the nozzle tip to the wall may
be 0.250 inch with a tolerance of .+-. 0.060 inch. Accordingly, by
means of this invention, manufacture and assembly are greatly
simplified, resulting in a highly effective instrument at a much
lower cost.
The described nozzle construction may be utilized in connection
with either a non-defrostable or a defrostable cryosurgical probe.
The probe illustrated herein is of the defrostable type. Defrosting
is obtained by means of the valve illustrated in detail in FIGS. 2
and 3. When the valve is in its normally open position as shown in
FIG. 2, high pressure gas entering through delivery line 16 passes
through the delivery tube 62 to nozzle 64. From the nozzle it
expands into tip 14 causing the tip to be cooled by the
Joule-Thomson effect. The expanded gas then passes rearwardly
through exhaust tube 74 and out of the instrument through the
T-fitting 26 and the recess 24. If desired, it may be remotely
exhausted through an exhaust line enclosing delivery line 16. The
high pressure exhaust gas tends to maintain the exhaust valve
formed by the ball 66 and the valve seat 82 in its normally open
position, with the ball retracted from the seat as shown in FIG. 2.
In order to defrost the instrument, the trigger 20 is depressed by
the surgeon, whereupon the trunnion ball 38 and the rods 40, 42
assume the positions illustrated in FIG. 3, forcing the ball 66
forwardly against the valve seat 82, forming a gas tight seal. With
the exhaust valve closed, gas pressure within tip 14 rises to
bottle pressure and the heat of compression causes rapid defrosting
of the probe tip. It is important to note, however, that either of
two different limit stops restrict the forward movement of ball 66.
These include the point C which may be contacted by the upper rod
40 and the point D which may be contacted by the lower rod 42. No
matter how much force is exerted on trigger 20, the ball 66 can be
driven no further forward than the limit set by a stop. This is a
very significant improvement because it means that, if the probe
tip 10 is not fully seated within the T-fitting 26, the exhaust
valve cannot be closed and pressurization cannot occur.
With an instrument of the type disclosed herein, a single handle
and valve unit may be supplied with a plurality of probes and tips
for performing various surgical procedures. These may be readily
interchanged by the surgeon or his assistant without the danger of
a probe being improperly inserted. Furthermore as the valve is
normally open, it will be closed only for the period of time during
which the surgeon desires to defrost the probe tip. Therefore, the
instrument is exposed to full bottle pressure only intermittently
and for short periods of time, greatly increasing the safety of the
apparatus.
It is believed that the construction and operation of this
invention will now be apparent to those skilled in the art. It will
also be apparent that a number of variations and modifications may
be made in this invention without departing from its spirit and
scope. Accordingly, the foregoing description is to be construed as
illustrative only, rather than limiting. This invention is limited
only by the scope of the following claims.
* * * * *