U.S. patent number 3,575,176 [Application Number 04/769,065] was granted by the patent office on 1971-04-20 for rechargeable cryosurgical instrument.
This patent grant is currently assigned to Frigitronics of Conn. Inc.. Invention is credited to Ralph E. Crump, Frank L. Reynolds, Victor A. Thyberg.
United States Patent |
3,575,176 |
Crump , et al. |
April 20, 1971 |
RECHARGEABLE CRYOSURGICAL INSTRUMENT
Abstract
This disclosure relates to a rechargeable cryosurgical
instrument having operating mechanism located at one end and a
refrigerant cartridge-receiving chamber opening to the atmosphere
at its other end. A removable end cap closes the open end of the
instrument and is selectively positionable to locate a housed
refrigerant cartridge in a dispensing or conserving position. In
the dispensing position of the end cap, the pressurized refrigerant
is dispensed from the cartridge through a delivery tube to a boiler
valve located adjacent a cooling tip to reduce the temperature of
the tip. The spent refrigerant is exhausted from the housing
through an opening in the removable end cap. A selectively operable
finger-actuable lever located at the exterior of the housing
operates the boiler valve to either cool or warm the cooling
tip.
Inventors: |
Crump; Ralph E. (Trumbull,
CT), Reynolds; Frank L. (Monroe, CT), Thyberg; Victor
A. (Fairfield, CT) |
Assignee: |
Frigitronics of Conn. Inc.
(Bridgeport, CT)
|
Family
ID: |
25084340 |
Appl.
No.: |
04/769,065 |
Filed: |
October 21, 1968 |
Current U.S.
Class: |
606/25; 62/293;
606/26 |
Current CPC
Class: |
A61B
18/02 (20130101) |
Current International
Class: |
A61B
18/00 (20060101); A61B 18/02 (20060101); A61b
017/36 (); F25d 003/00 () |
Field of
Search: |
;128/400,400 (X)/
;128/254,303,399,401 ;62/6,55,292,293 ;165/24,27 ;62/514 ;220/40
;128/303.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Mitchell; J. B.
Claims
We claim:
1. A rechargeable cryosurgical instrument comprising a body
defining a refrigerant cartridge-receiving chamber, opening to the
atmosphere, at one end and a cooling tip at the other end; boiler
valve means in said body adjacent said cooling tip; a reciprocable
member in said body located between said chamber and said cooling
tip, carrying a delivery tube at one end and having an opening in
its opposite end to receive the dispensing tube of a refrigerant
cartridge; control means connected to said reciprocable member and
extending to the exterior of said body, being selectively operable
to move said boiler valve means for cooling or warming said cooling
tip; means for exhausting spent refrigerant from said cooling tip
to said chamber; a removable end cap seated in the open end of said
body; and positioning means on said end cap and said body
cooperating to selectively locate said end cap in a first position
for retaining a refrigerant cartridge in said chamber in a
nondispensing condition and a second position forcing the
dispensing tube of said cartridge against said reciprocable member
to release refrigerant into said delivery tube.
2. The rechargeable cryosurgical instrument defined in claim 1
wherein said positioning means linearly guides said end cap between
said first and second positions.
3. The rechargeable cryosurgical instrument defined in claim 1
wherein said positioning means includes a positioning slot defined
in the wall of said body adjacent said open end, and a radial
positioning pin located on said end cap.
4. The rechargeable cryosurgical instrument defined in claim 3
wherein said positioning slot has a first pin-receiving seat to
position said end cap to urge a housed replaceable refrigerant
cartridge into a refrigerant conserving position.
5. The rechargeable cryosurgical instrument defined in claim 3
wherein said positioning slot has a second pin receiving seat to
position said end cap to urge a housed refrigerant cartridge into a
refrigerant-dispensing position.
6. The rechargeable cryosurgical instrument defined in claim 1
wherein said end cap defines a vent therethrough.
7. The rechargeable cryosurgical instrument defined in claim 1
wherein said positioning means includes a positioning slot defined
in the wall of said body adjacent said open end and a radial
positioning pin located on said end cap, said positioning slot
having a first pin-receiving seat to position said end cap relative
to said body to urge a housed refrigerant cartridge into a
refrigerant-conserving position and a second pin-receiving seat to
position said end cap to urge a refrigerant cartridge into a
refrigerant-dispensing position, and said end cap defines a vent
therethrough.
8. The rechargeable cryosurgical instrument defined in claim 1
wherein support means are provided on said reciprocable member to
maintain said reciprocable member in position to receive the
dispensing tube of a refrigerant cartridge.
9. The rechargeable cryosurgical instrument defined in claim 1
wherein said control means comprises a pivotable lever; said
reciprocable member includes a seat formed therein to receive one
end of said lever; and said body defines an opening therein through
which said lever passes, positioned to be in substantial alignment
with said seat, the rim of said opening forming a fulcrum about
which said lever pivots.
Description
BACKGROUND OF THE INVENTION
This invention relates to a rechargeable cryosurgical instrument
and, more particularly, to such a device designed for delicate
surgery, which is normally cold when in use and may be rapidly
warmed as desired, and in which means are provided to conserve the
refrigerant when the instrument is not in use.
The phenomenon of moist tissue adhering to cold metal is well known
but until recently was seldom surgically utilized. Recently,
cryoextraction has become a formidable opthalmological procedure
based on this phenomenon. One use now made of this procedure is the
intracapsular extraction of cataracts. Cataract surgery, which is
one of the most delicate operations that a surgeon is called upon
to perform, involves the removal of an opacified lens. Usually the
lens, which comprises a very thin membrane containing a fluid, is
extracted whole through an incision made at the intersection of the
cornea and the outer edge of the iris. Most commonly in the past
this has been accomplished by the exertion of traction thereon by
means of a suitable device, for example, specially designed
forceps. Although the cataract operation has been greatly improved
in recent years by the use of better traction instruments, they
have a tendency to cause the membrane to rupture. With the advent
of the procedure of cryoadhesion and the invention of various
surgical instruments based upon this principle, it is possible to
provide the surgeon with a safe, reliable, and easily manipulatable
instrument with which to accomplish the intracapsular extraction.
This is done by contacting the lens with a cryosurgical instrument
having a tip which may be cooled by a refrigerant that boils at
approximately -30.degree. C. The temperature of the tip on the warm
lens is apt to be -10.degree. to -20.degree. C, depending on the
duration of application. This freezes the membrane and forms an
intralenticular ice mass contiguous to the probe which assists in
distributing the extraction force over a large area of the membrane
to prevent its rupture.
The principle of cryoextraction is also utilized in removing
nonmagnetic intraocular foreign bodies, such as wood splinters. In
such a surgical operation it is possible to introduce the probe of
a cryosurgical instrument into the pupil and place it beside the
foreign matter. As the tip of the probe is made cold, it freezes
the adjacent vitreous and an expanding ice ball engulfs the foreign
matter. By withdrawing the probe towards the surface but thawing
and refreezing it at frequent intervals, it is possible to extract
the ice-encased foreign matter from the vitreous without removing
the central portion of the vitreous body in the process.
Inevitably, the final removal of the foreign matter involves the
loss of some of the surrounding vitreous, but this can be minimized
by controlling the exit wound with sutures and by partially thawing
the probe in the final stages of extraction.
Various cryosurgical instruments have been developed to utilize the
technique of cryosurgery. These fall into three general categories,
namely: (1) continuously operating units; (2) disposable
instruments which may be used but a single time; and (3) solid
probes which are cooled merely by being immersed in a cold liquid
such as alcohol and dry ice. The first category is represented by
various high-priced systems such as those operating on the Peltier
effect, which must be connected to a source of electrical power, or
those having a remote supply tank of a suitable refrigerant which
must be piped to the instrument. The latter may also require a
suction pump to exhaust the refrigerant to vary the degree of
cooling of the tip. These instruments are designed to allow the
surgeon to quickly warm the tip so that he may disengage it from
the tissue inadvertently adhered thereto. Conventional instruments
in the second and third categories, while being considerably less
expensive than those of the first category, have the distinct
disadvantage of lacking integral warming means and require the
application of an externally applied warming medium to the area of
the cryoadhesion if the surgeon should accidentally touch adjacent
healthy tissue with the tip of the cold probe. This is usually
accomplished by irrigating the area with a warm saline solution and
generally requires the intervention of another sterile person in
the operating room. Alternatively, some prior art instruments are
defrosted by means of an electrically heated wire. This creates a
potentially dangerous situation in explosive environments and also
requires a separate control. Furthermore, the instruments falling
in these categories are generally crude and are often of dubious
sterility.
SUMMARY OF THE INVENTION
Accordingly, it is the primary object of this invention to provide
a cryosurgical instrument in the form of a rechargeable unit having
a chamber therein to receive a cartridge of pressurized
refrigerant.
Another object is to provide a cryosurgical instrument of the type
described in the above paragraph, wherein the instrument includes
valving to render the tip of the probe normally cold and means are
provided to selectively warm the tip.
Still another object of this invention is to provide a rechargeable
cryosurgical instrument which is lightweight, compact and
inexpensive and which includes means to position the cartridge
within the instrument body to prevent discharge of the refrigerant
therefrom when the instrument is not in use.
To accomplish these objects, in one form a rechargeable
cryosurgical instrument is provided having a body defining a
refrigerant cartridge-receiving chamber opening to the atmosphere
at one end and a cooling tip at the other end. The body houses a
boiler valve adjacent the cooling tip and valve-operating means
between the chamber and the cooling tip. Control means for the
valve-operating means extends from the interior of the body to the
exterior thereof and is selectively operable to move the boiler
valve for cooling or warming the cooling tip. Means are provided
for delivering the refrigerant from a refrigerant cartridge in the
body chamber to the cooling tip and means are provided to exhaust
the spent refrigerant from the cooling tip to the chamber. A
removable end cap located in the open end of the body defines a
vent therein and includes means for being selectively located in a
refrigerant-conserving or in a refrigerant-dispensing position.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and further details of that which is believed to be
novel and the invention herein will be clear from the following
description and claims taken with the accompanying drawings,
wherein:
FIG. 1 is a perspective view of the rechargeable cryosurgical
instrument constructed in accordance with this invention;
FIG. 2 is a side elevational view of the rechargeable cryosurgical
instrument with its end cap removed and partially broken away to
show the end cap-positioning slot;
FIG. 3 is a side elevational view of a typical valved refrigerant
cartridge;
FIG. 4 is a partial top plan view of the end of the rechargeable
cryosurgical instrument showing the end cap relative to the
positioning slot;
FIG. 5 is a longitudinal sectional view of the rechargeable
cryosurgical instrument shown with the end cap in the
refrigerant-conserving position;
FIG. 6 is a longitudinal sectional view similar to that of FIG. 5
showing the rechargeable cryosurgical instrument with the end cap
in the refrigerant-discharging position for normal cooling;
FIG. 7 is a partial longitudinal sectional view similar to that of
FIG. 6 showing the instrument in its thawing condition; and
FIG. 8 is an enlarged partial longitudinal sectional view showing
the cooling tip in detail.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings, there is illustrated in FIG. 1 a
rechargeable cryosurgical instrument generally referred to by the
numeral 10. It is in the form of a pencillike instrument having a
body 12 with a probe 14 at one end, terminating in a tip 16, an
operating lever 18 overlying the forward portion of the body, and a
removable end cap 20 selectively movable into several positions in
positioning slot 22 at its other end. The instrument is
lightweight, the body 12 being made, for example, of a suitable
metal or plastic material. As this instrument is rechargeable and
therefore reusable, as will become apparent hereinafter, the
material of which the body is made must be chosen so as to be
dimensionally stable and otherwise unaffected by the use of a
sterilizing gas such as ethylene oxide. Similarly, the material may
be autoclavable.
Turning now to the details of the instrument, the removable end cap
20, also made of metal or plastic, comprises a cylindrical body 24
with an enlarged cylindrical knurled head 26 at one end, a smaller
diameter central axial boss 28 at the other end, and an axial vent
30 passing through the body 24 and head 26. A radially extending
positioning pin 32 located near the forward end of the body 24
cooperates with the positioning slot 22 defined in the thin wall of
the instrument body. The positioning slot is of generally steplike
configuration, including an axial entrance leg 34, a first
positioning leg 36 terminating at its right end (as viewed in FIG.
4) in a first positioning seat 38, and a second positioning leg 39
having a positioning seat 40. Step portion 42 connects the entrance
leg 34 with the first positioning leg and step portion 44 connects
the first positioning leg with the second positioning leg 39.
The instrument body 12 is in the form of a generally cylindrical
thin-walled shell defining a large chamber 46 to receive a
refrigerant cartridge 48. The internal mechanism of the
rechargeable cryosurgical instrument will now be described with
reference to FIGS. 5, 6 and 7. Located at the left end of the
chamber 46 there is a reciprocable shuttle 50 including an axial
bore 52 having a chamfered entrance 54 at one end and an axial
concentric passage 56 extending to its other end. Several finlike
support ribs 57 (one shown) are located at the lower end of the
shuttle to assist in positioning it in the body 12 in the absence
of the cartridge 48. A sealing O-ring 58 and a positioning ring 60
are disposed within the bore 52 and a small diameter delivery tube
62 is located within the passage 56, being secured in place within
the bore of the positioning ring 60 with the left end of the
delivery tube extending out of the body of the instrument. The
shuttle 50 further includes a seat 64 defined therein to receive
the end 66 of the operating lever 18 which passes through an
opening 68 in the body formed through the wall thereof. The opening
is sealed by a resilient sealing ring 70 encircling the lever which
is held in place by means of a snap-type retaining ring 72.
An exhaust valve 74 located at the left end of the shuttle 50
includes a sealing O-ring 76 seated in a circumferential groove 78
in the shuttle which cooperates with a radially inwardly turned lip
80 formed at the end of a thin-walled metallic cylindrical shell
82. The shell 82 is secured in a suitable manner to a collar 84
such as by being crimped thereon as at 86. An O-ring 88 seated
between the shell and the collar effectively prevents gas leakage
between these two members. The collar 84 is securely mounted upon
an exhaust tube 90 at one end thereof and supports the exhaust tube
so that it coaxially surrounds the delivery tube 62 forming the
probe 14 extending outwardly from the body 12 through an axial
opening 92 therein which opening is sealed by means of O-ring
94.
As clearly illustrated in FIG. 8, the cooling tip 16 is in the form
of a metal plug 96 which seals the open end of the exhaust tube 90
to prevent gas flow therefrom. It is made of a suitable metallic
material selected to provide a path of high thermal conductivity
therethrough. The exterior portion of the tip is shown as being
rounded; however, it may comprise any configuration designed to
perform a particular surgical function. A boiling chamber 98 formed
at the interior of the probe 14 adjacent the cooling tip 16
includes a boiler valve which when closed will allow the gas to
expand through a metering orifice 100. The form of the boiler valve
illustrated in FIG. 8 is but one example of the several
constructions comprehended by this invention. It includes a conical
valve seat 102 integral with the cooling tip 16 which cooperates
with the machined open end 104 of the delivery tube 62 in which the
metering orifice 100 is cut. An annular passage 106 in the probe 14
between the delivery tube 62 and the exhaust tube 90 extends from
the boiling chamber 98 to a chamber 108 defined between the collar
84 and the exhaust valve 74.
The entire assembly of: the shuttle 50 carrying the positioning
ring 60, the delivery tube 62 and the O-ring 76, and the collar 84
carrying the exhaust tube 90 and the shell 82 is held in the body
12 against the sealing O-ring 94 by means of a springlike
washer-type retaining ring 110. This assembly is the reusable
portion of instrument 10 which receives the refrigerant cartridge
48.
The cartridge 48, made of metal for good strength and lightweight,
contains approximately 10--12 cc. of a suitable pressurized
refrigerant which may be a liquid, such as Freon 12 (a mark of
Dupont for dichlorodifluoromethane), or a gas, such as CO.sub.2. In
the illustrated Freon version, an aerosol-type valve 112 is
disposed at one end of the cartridge 48 and is secured by means of
a metal cap 114 which may be turned into a circumferential recess
116 in the cylindrical wall of the cartridge. The aerosol-type
valve 112 clearly illustrated in FIGS. 5 and 6 includes a valve
stem 118 whose right end is in the form of a solid rod portion 120
and whose left end is in the form of a tubular portion 122 open at
one end defining a radial port 124 therethrough. A flange 126
girdles the rod adjacent the midpoint thereof. Resilient sealing
ring 128 is positioned adjacent the planar end wall of the cap 114
tightly encircling the left end of the valve stem 118 which passes
through an opening in the cap end wall. A valve body 180 includes a
radially outwardly extending circumferential flange 132 captured
between the cap 114 and the mouth of the tank. A central axial bore
134, in the valve body 130, terminates in a lip 136 which receives
the rod portion 120 of the valve stem 118 and its associated
compression spring 138 which biases the valve stem 118 in a
leftward direction. Thus, the port 124 is positioned normally at
the exterior of the cartridge 48 to prevent discharge of the
refrigerant.
The rechargeable cryosurgical instrument 10 is presented to the
surgeon in the operating room in a sterile condition. The
refrigerant cartridge 48, preferably containing a sterile
pressurized refrigerant, is also delivered to the surgeon in the
operating room in a sterile condition and be packaged in a sterile
pouch. In order to utilize the instrument, the refrigerant
cartridge 48 is inserted into the body chamber 46 and the tubular
portion 122 of the valve stem 118 is directed into the chamfered
entrance 54 and the axial bore 52 of the reciprocable shuttle 50
and is seated against the O-ring 58. Then the end cap 20 is
inserted into the open end of the body, the positioning pin 32
entering the entrance leg 34 of the positioning slot 22 so that the
end cap boss 28 abuts the end of the refrigerant cartridge 48 and
drives it leftwardly into the body 12. Initially, the tubular
portion 122 of the valve stem 118 is urged into contact with the
sealing O-ring 58, then the shuttle 50 is moved leftwardly, urging
the delivery tube 62 against the conical valve seat 102. Further
insertion of the end cap 20 carries the tank of the refrigerant
cartridge 48 over the valve stem 118 compressing the compression
spring 138. When insertion of the end cap 20 is stopped as the
positioning pin 32 abuts the step portion 42, it should be rotated
in a clockwise direction until the positioning pin abuts the first
positioning leg 36. Releasing the end cap allows the compression
spring 138 to snap it rearwardly to lodge the positioning pin in
the first positioning seat 38. It should be noted with reference to
FIG. 5 that in this first position the port 124 of the aerosol-type
valve underlies the resilient sealing ring 128 so that the
pressurized refrigerant is unable to escape the cartridge. In this
first or "ready" position of the rechargeable cryosurgical
instrument 10, the refrigerant may be conserved and the instrument
is ready for use.
When he wishes to use the cryosurgical instrument, the surgeon may
initiate the normal cooling of the tip 16 by pushing the end cap 20
further into the body, moving the cartridge against the bias of the
compression spring 138, to move the positioning pin 32 in the first
positioning leg until it abuts the step portion 44 and then
rotating the end cap in a clockwise direction until the positioning
pin 32 abuts the second positioning leg. Releasing the end cap
allows the compression spring 138 to snap it rearwardly to lodge
the positioning pin 32 in the second positioning seat. In this
position, as shown in FIG. 6, the refrigerant cartridge has been
moved leftwardly over the valve stem so that the port 124
communicates the interior of the cartridge with the exterior
thereof in the manner of actuating a usual aerosol-type valve. In
this condition the pressurized refrigerant may escape the tank
through the port 124, passing between the solid rod portion 120 of
the valve stem 118 and the bore 134 of the valve body 130 past the
compression spring and the flange 126. Since the instrument body is
open to the atmosphere through the gas port 30 in the end cap 20,
the pressurized refrigerant seeks an escape path thereto and flows
from the cartridge 48 through the port 124 and the tubular portion
122 of the valve stem 118, down the delivery tube 62 to the boiling
chamber 98 where it passes through the metering orifice 100 in the
open end of the delivery tube. The sharp drop in pressure occurring
across the metering orifice 100 permits the refrigerant to expand
rapidly, absorbing heat from the area of the cooling tip 16 to cool
it rapidly to a temperature low enough to cause cryoadhesion of the
tip to warm moist tissue. The expanded and warmed spent gas is
conducted through the annular passage 106 to the chamber 108 where
it flows out the open exhaust valve 74 through the annular passage
defined between the refrigerant cartridge 48 and the inside wall of
the body 12, and out the gas port 30 to the atmosphere. This is the
only path available to the escaping gas since the axial opening 92
in the body is sealed by the O-ring 94, and the opening 68 in the
body through which the lever end 66 enters is sealed by the
resilient sealing ring 70.
If, as the operation progresses, the surgeon inadvertently contacts
adjacent healthy tissue, such as the cornea or the iris, these
tissues will also freeze and adhere to the cooling tip 16. In such
case the surgeon must immediately disengage the tip. This may be
quickly and easily accomplished by depressing the lever 18 (note
FIG. 7) which is located under his index finger. Warming of the tip
takes place in the following manner. The lever end 66 is pivoted
about the edge of the opening 68, thereby applying a force against
the right side of the seat 64 to move the shuttle 50 against the
compression spring 138 through O-ring 58 and the valve stem 118.
Movement of the shuttle 50 toward the right withdraws the delivery
tube 62 slightly from the conical valve seat 102, permitting a
flood of warm refrigerant to flow into the annular passage 106 and
into the chamber 108. The lip of the shell 80 and the O-ring 78
forming the exhaust valve 74 are disposed in such a relationship
that when the lever 18 is pivoted and draws back the shuttle 50,
the exhaust valve 74 will be closed after a small amount of warm
refrigerant is permitted to escape from the chamber 108 to ensure
that the chamber 108 and the annular passage 106 are full. When the
exhaust valve 74 has been completely closed, the pressure built up
within the chamber 108 and the annular passage 106 prevents the
refrigerant from boiling with the resultant heat absorption. Thus
the sensible heat of the refrigerant brought into the end of the
probe is sufficient to warm the tip 16 to permit disengagement of
the tip from the tissue.
As long as the lever 18 is maintained in the depressed position the
tip 16 will be warm. It is merely necessary for the surgeon to
release the lever to cause the shuttle 50 and the delivery tube 62
to move leftwardly under the bias of the compression spring 138 and
return the instrument 10 to the normally cold operating condition
as illustrated in FIG. 6.
If the surgeon desires to utilize some other surgical instrument,
the cryosurgical instrument of this invention may be temporarily
deactivated to conserve the refrigerant charge. This may be
accomplished by moving the end cap 20 to the first position, as
clearly illustrated in FIG. 5. When the refrigerant has been
exhausted, the end cap 20 can be removed to dispose of the spent
cartridge and a second cartridge may be inserted if necessary.
It should also be understood that there often exist conditions
which require that the probe be introduced to the tissue in a warm
condition prior to cooling. If, for example, the lens has been
displaced from its normal position and has slipped back into the
vitreous, it must first be located with the tip of the probe and
then the lever must be released to quickly freeze the lens to the
tip so that it may be withdrawn from the vitreous. Therefore, it is
within the comprehension of this invention to reverse the operation
of this rechargeable cryosurgical instrument by having the cooling
tip normally warm and rendering it cold by manual actuation of the
control lever.
Having described this invention of a rechargeable cryosurgical
instrument, it should be readily appreciated by those skilled in
this art that there is provided herein an instrument which is
simple in design, low in cost and ingenious in operation. As set
forth in the objects, there is provided a rechargeable instrument
that may be selectively heated or cooled at the option of the
surgeon and which is compact and easy to handle and which may be
rendered temporarily inactive to conserve the refrigerant
charge.
It should be understood that the present disclosure has been made
only by way of example and that numerous changes in details of
construction and the combination and arrangement of parts may be
resorted to without departing from the true spirit and scope of the
invention as hereinafter claimed.
* * * * *