US 3455304 A
Description (OCR text may contain errors)
y 1969 J. AGANS 3,455,304 I cnxosx'rmc'ron Filed Oct. 6, 1966 INVENTOR 4 JEROME A. GANS ATTORNEYS United States Patent Claims ABSTRACT OF THE DISCLOSURE A cryoextractor is provided having a cold-conducting Mt. r
cryoextractor tip mounted in one end of the casing and protruding therefrom, having a completely closed capsule wholly within this casing and in cold conducting contact with the tip with the liquid in the capsule which freezes at a temperature below the freezing point of water, and with the end of the casing opposite the tip being open and of such a size that the capsule is removable and insertable through this Opening, together with a cap for securely closing that opening. This permits a capsule to be kept in a refrigerator at the desired cold temperature, then taken out of the refrigerator at the time of use and inserted through the open end of the casing even when the capsule is in an unsterile condition, thus necessitating only a sterile casing. After the use the capsule is quickly removable through the opening and can be replaced in the refrigerator for re-use.
This invention relates to improvements in a cryoextractor used in cataract operations and wherein a very cold tip of the instrument is applied to the moist anterior surface of the lens of the eye to which it adheres by freezing, thus enabling the doctor to extract the lens intact.
One of the objects of the present invention is to provide a cryoextractor which is efficient in its operation but which also maintains the sterile condition of the operating area.
Another object of the present invention is to provide a cryoextractor wherein the cooling medium is in a completely closed capsule which provides a cooling medium for one use of the instrument, after which the capsule can be refrozen and used again.
Another object of the invention is to provide a capsule filled with a product of rather low cost but which provides a cold source for cooling the cryoextractor tip, which cold source is free of escaping evaporating gases which can be a source of contamination.
Other objects and advantages of the invention will be apparent from the accompanying drawings and description and the essential features thereof will be set forth in the appended claims.
In the drawings:
FIG. 1 is a central sectional view, enlarged, and taken generally axially through the instrument of this invention with a portion of the cooling capsule broken away to more clearly show the construction;
FIG. 2 is an exploded view showing the significant parts of FIG. 1 in slightly disassembled relationship;
FIG. 3 is a view of a modification; while FIG. 4 is a sectional view along the line 44 of FIG. 1.
Cryoextractors have been heretofore used in cataract operations but those commonly known release non-sterile gases in the operating area which is very undesirable. The present invention overcomes this disadvantage.
Referring to FIGS. 1 and 2, this improved cryoextractor includes a casing 10 which may be of any suitable material, but preferably is made of a synthetic plastic, nylon having been successfully used in one embodiment. This casing is closed at the right-hand end except for the tip which will be later described. The casing is normally open at the left-hand end as viewed in FIG. 1 and means is pro- 3,455,304 Patented July 15, 1969 "ice vided for closing this end which in this case is a cap 11 having a threaded connection at 12 with the casing 10. An operating tip 13 extends from the right-hand end of the casing as viewed in FIG. 1 and this is made of a good heat conductor such as copper or silver. The inner end of this tip must be in cold conducting contact with a capsule 14 which is adapted to cool the tip to a temperature below the freezing point of water or colder. In the embodiment of FIGS. 1 and 2, the mutually engaging ends of the capsule 14 and the tip 13 have interfitting projection and recess portions whereby to increase the cold-conducting area between them. In the form shown, these are at least partially conical and include the conical end 13a on the tip 13 which fits closely a conical recess having walls 14a at the right-hand end of the capsule 14 as viewed in FIGS. 1 and 2. Preferably the casing 10 has a few longitudinal ridges 10a as shown in FIG. 4 to minimize cold loss from the capsule to the casing which acts as a handle.
For more efficient operation, insulation 15 is applied around the tip 13 leaving only the operating end exposed. In the position of the parts shown in FIG. 2, the cold insulation 15 has been slidably moved away from the tip end 13a to more clearly disclose the construction. It is desirable to provide means for maintaining good cold conducting contact between the tip 13 and the capsule 14. In the drawings, a helical compression spring 16 is shown confined between a cup-like member 17 in the cap 11 and the left-hand end of the capsule 14. The parts are so arranged that when the threads 12 are connected, the cap holds the spring slightly compressed against the capsule 14.
The capsule 14 is completely closed and contains a liquid which freezes at -35 centigrade or colder, preferably. In one form of this invention I have utilized a water solution of ethylene glycol material sold commercially as Prestone. Other suitable liquids are alcohol, a salt water solution, or a glycerin solution. These are well known and can be prepared without difficulty. I have successfully used such a Prestone solution freezing at 40 centigrade, although solutions freezing at 50 to 70 centigrade may also be used. It is desirable that the operating end of the tip 13 be cooled to 5 centigrade and this is readily arranged with the cold conducting contact here disclosed between the tip 13 and the capsule 14.
A modified form is shown in FIG. 3 where all parts having the same function are given the same reference characters and the only difference here is that the capsule 14' has a flat end 14b contacting a flat circular disc 13b formed at the inner end of the tip 13 and integral therewith. This provides a good cold conducting surface between the tip 13 and the capsule 14' although it does not have the cold conducting area of the first described embodiment.
In use of this invention, a supply of capsules 14 is kept in a refrigerator of any type at any desired temperature, say 35 centigrade or lower. When the implement is to be used, the outer casing is autoclaved for sterility. The cold capsule 14 is transferred unsterile from the refrigerator and slipped into the sterile casing 10 and cap 11 is threaded on the casing as shown in FIG. 1 in a manner familiar to all operating room personnel where unsterile material is locked into a sterile casing so that from that moment on, the instrument is completely sterile to the outside world and further handling is all in a sterile manner. In a few moments the tip 13 is cold enough to be used and after the operation, the warm capsule 14 may be removed and replaced in the refrigerator to be frozen for subsequent use. This provides a sterile operating instrument without the disadvantages of previously known instruments of this general character which use carbon-dioxide, or liquid nitrogen as the cold source and therefore have constant evaporation of gases escaping from the instrument. As the same time, the fact that the capsules 14 may be re-used many times cuts down the cost of utilizing this improved implement.
The device shown in the drawing is slightly enlarged from one which has been actually used which measured about 4%. inches from the left-hand end of cap 11 to the right-hand end of casing 10 and was about /2 inch in diameter so that it was easily held in the hand of the doctor. The tip 13 extended about inch from the end of the casing 10.
What is claimed is:
1. In a cryoextractor, a casing, a cold-conducting cryoextractor tip mounted in one end of said casing and protruding therefrom, a completely closed capsule wholly within said casing and in cold-conducting contact with said tip, a liquid in said capsule which freezes at a temperature below the freezing point of water, the end of said casing opposite said tip being open, said capsule being removable through said opening, and a cap for securely closing said opening.
2. A cryoextractor as defined in claim 1 wherein a spring is compressed between said cap and said capsule when said cap closes said opening whereby to cause one end of said capsule to press "against said tip.
3. A cryoextractor as defined in claim 2 wherein mutually interfitting projection and recess portions are provided on saidvmutu-ally engaging ends of said capsule and tip increasing the cold-conducting area between them.
4. A cryoextractor as defined in claim 3 wherein said mutually interfitting portions are at least partially conical, or interleaved, and concentric relative to said capsule and tip whereby the interfitting action between them is self-centering.
5. A cryoextractor as defined in claim 4 wherein said capsule and casing are cylindrical having their length at least four times their diameter and easily held in the hand of an operator.
References Cited UNITED STATES PATENTS 2,959,038 11/1960 Baird 62293 XR 3,190,081 6/1965 Pytryga 62-293 3,270,744 9/1966 Katz et a1 l28303.1
L. W. TRAPP, Primary Examiner