US2825339A

US2825339A - Refrigeration applicator

Info

Publication number: US2825339A
Application number: US607319A
Authority: US
Inventors: James D Mcgee
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-10-26
Filing date: 1956-08-31
Publication date: 1958-03-04
Anticipated expiration: 1975-03-04

Description

March 4, 1958 .1. D. MGGEE REFRIGERATION APPLICATOR Filed Aug. 51, 1956 bin/EMT;

2,825,339 I REFRIGERATION APPLIYCATOR James D. McGee, London, England Application August 31, 1956, Serial No. 607,319 9 Claims. or. 128-403) This invention relates to an instrument for applying refrigeration to localized areas, e. g. to the human skin, and which may therefore be termed a refrigeration applicator.

In medical practice it is often desirable to apply very low temperatures to local areas of the skin for the purpose of removing warts, moles or similar undesirable skin blemishes. The local freezing of the tissues results in the destruction of the unwanted cells. This is usually done by applying a stick about /1 in diameter of compacted carbon dioxide snow, at at temperature of about -80 C. to the unwanted object.

Alternatively a slush made by mixing carbon dioxide snow with acetone is sometimes used, or even liquid nitrogen or liquid oxygen.

The use of such refrigerants has the following disadvantages:

(1) A stick of carbon dioxide snow compressed by a plunger in a plastic cylinder is blunt and may cover a larger area of skin than it is wished to treat. This difficulty can be overcome by having a number of compression cylinders of different diameters; or the stick can be sharpened by applying it with rotation on its axis to a metal surface; a cone or truncated cone of snow results.

(2) A stick of carbon dioxide snow slowly diminishes in diameter while being used, whether it be a cylinder, a truncated cone, or a cone. This loss of diameter through evaporation can be lessened by applying the stick in a plastic cylinder without extruding it from the end of the cylinder. This entails loss of visual control and loss of pressure on the skin because it is difiicult to maintain steadypressnre equally on the cylinder and on the snow contained in it. The plunger must be pressed in gradually as the snow evaporates.

(3) If the stick is applied with pressure to an area of skin of uniform consistency while it is extruding from the compression cylinder, it will cause freezing of an indented disc of skin; the walls of the indentation also become frozen and an unnecessarily large area of skin may blister as a result.

(4) Carbon dioxide snow-acetone slush is not easy to manipulate. Applied to a camel hair brush or by means of a cottonwool tipped wooden applicator, it may accidentally be dropped on to an area of skin it is not wished to treat, with painful and embarrassing results. If the mixture drops on to rayon clothing solution of the cellulose acetate results.

(5) It is difiicult to apply carbon dioxide slush accurately to small lesions. This is also true of liquid nitrogen and liquid oxygen which have to be applied with a cotton-wool tipped applicator.

(6) The quantity of refrigerant conveniently prepared quickly vaporises so that normally only one application is possible.

Attempts to make applicators have not heretofore overcome these difiiculties.

A United States Patent C ice According to the present invention an applicator comprises two glass tubes one within the other, the inner tube being open at both ends and the other tube being sealed to the inner tube at spaced positions to form a sealed space between the tubes which is substantially evacuated.

The refrigerant can be fed into one end of the inner tube, and pressed out of the other or application end or a metal heat conductor may be provided in the inner tube and which extends out of the application end of the latter. in either arrangement the evacuated space holds the refrigerant at its low temperature for comparatively long periods, facilitates holding and applying of the applicator, and enables the user to effect close control of the area being treated.

The invention will now be further described by way of example with reference to the accompanying diagrammatic drawings wherein:

Figure l is a sectional view of an applicator made in accordance with the invention; and

Figure 2 is a view on a larger scale of part of Figure 1.

in the construction shown in Figures 1 and 2 an inner tube It} is located concentrically within an outer glass.

glass 11. These tubes are of round section and are made of a glass suitable for withstanding high and low temperatures within minimum tendency to crack. At the application end, the inner tube is tapered at 12 to a neck' 13 of reduced diameter at its end. At its other end the inner tube is formed with an outwardly extending flange 15 at such an angle that it forms a funnel to facilitate filling of refrigerant into the tube. The outer tube is spaced from the inner tube and its application and is tapered and sealed by fusing it at 17 to the end of the inner tube. The other end of the outer tube is formed with an outwardly extending flange 18 which is at to the axis of the tubes. Although 90 is preferred a slightly less angle of from 85 to could be tolerated. The flange 13 has the important function of providing some resilience for accommodating diiferential expansion or contraction of the

tubes

10, 11 to avoid cracking the The flange 18 carries a tubular extension 19 at its outer edge and thi extension is fused to the flange 15 at 213. A space 21 is thus sealed olf between the positions 17, 2%} that are spaced apart along the inner tube and this space is evacuated and sealed at nipple 22. The

joints

17, 20 could be at places other than those shown.

A metal conductor is provided consisting of a tube 25 having a solid end 26. This conductor is made of an efiiciently heat-conducting metal such as copper or silver. The tube fits with a tight push fit in the inner glass tube so that it does not loosen when at a low temperature. The solid end 26 is tapered down to a neck of small diameter at its end that passes out of the end of the tube 10 and has a wire ring 25 soldered to it to prevent axial movement of the conductor in the tube 10. The latter has an inwardly extending projection 30 which engages in a depression in the part 26 to prevent rotary movement of the conductor in the tube 10. The part 26 has a formation consisting of a tapped hole 32 into which the screwed stem 34 of any of a series of buttons 33 can be engaged. These buttons will be of various sizes and the button will be selected according to the area to be treated.

The funnel 15 after insertion of the refrigerant may be closed with a cotton wool or other packing 35 and a cap 36 of metal, polythene or other suitable material.

In operation, a charge of CO snow, or CO snow and acetone slush of liquid nitrogen or of liquid oxygen is filled into the inner metal cylinder. A good deal will volatilize or boil off in cooling the inner metal and glass parts down to the very low temperatures of the refrig- '35 which must, however bes o" designed as ,toallow some escape-tot the vapourizing refrigerant, and; with the cap Because of the very efiicie nt conduction of heat by the metal sleeve 2 5, the protruding metal stub or' 'neck 26 is kept verynear the temperature of the refrigerant filling the cylinder 25. When thisfstub'is brought into contact with the warm'skin' the heat is conducted awaysuificiently of outwardly extending flanges.

' 3. An applicator as claimed in'claim l whe rein the connection between the tubes. at one" end includes 4. An applicator as claimed in claim.3 wherein at least one of the flanges is at an angle of from 85 to 951 to the axis of the tubes. 7

rapidly to pause freezing of the underlying skin. However; becausecf the vacuum 'shellsurrounding the cylinder;25, the outer wall 11 is 'net' uncomfortably coldfand project out of one end of the inner tube; V r a 7 7 r J 8. An applicator asclaimed: in claim 7 wherein the:

5. An applicator as claimed in claim 3lwhereinlone flange'forms an inlet funnel for the inner tube.

6. An applicator as claimed in claim'l wherein the; i

application end of the outer tube is'tapered. i

7. An applicator as claimed in claim 1 wherein 'a metal as to;

heat conductor is mounted in the inner tube so metal conductor is a tube having 'a'tight fit in the inner '7 glass tube, saidrmetal tube being" open at one end and canbeliandled without disccmfortg Moreover, since heat j tive for a considerable time, e. g. 30 to 60 minutes, de: pending on circumstances, afterjbeing iilled with a charge of CO2 snow Whileany of the refrigerant remains in the instrument the temperature of the applicator remains constant. Only when the refrigerant has all disappeared will the applicator begin to slowly return to room temperature. ,Whcn not inruse the lower end on the instrument. should be covered witha rubber cap to minimize condensation of Water vapour and loss of cold by contact of the stub with the warm air.

I claim: a V a v a l. A refrigeration applicator comprising two glass tubes one within the other, the inner tube being open at both i carinotjenter' the instrument at all readily except through t the inetal stub or neck 26, the instrument remains operaends and the other. tube being sealed to the inner tube, 1

at spaced positions, to form a sealed space between the tubes which substantially evacuated, and a metal heat conductor mounted in the inner tube so as to project 7 out of one end of the inner tube.

2. An applicator as claimed in claim 1 wherein one end of the inner tube is larger than thev other and the spaced positions are the ends of the tubes.

solid at its other end where it is of reduced diameter 7 I and projects throughjthe opcnend of the innerjglass' tube; 2' '9'. -An applicator as: claimed in claim 7 whereinjthe; metal conductor'is a tube having a tight'fi't inthe: inner 1 glass tube, said metaltube being open at one end and; 7

solid at its other end where it is of reduced diameter and projects through the open end ofthe inner glass .tube, and wherein the'metal tube is pr'evented from rotating. in the inner glass tube by a projection on one'of these tubes engaging a depression in the other, and a wire ring V soldered to the projecting end of the metal conductor prevents relative axial movement between the lattertand the inner glass tube.

References Cited in the file of, this patent UNITED STATES PATENTS 2 ,305,367 2,387,258

OTHER REFERENCES,

The .Lancet, for Aug. 11, in Scientific Library.)

Webb Dec. 15,1942 Hague Oct. 23', 1945 1956, pp. 290-91; (Copy: