DE2220828A1 - Injection and leak-proof, syringe-like cryosurgical instrument - Google Patents

Description

PATENTA N V / OLD

DR. PHIL. G. NlCKtTL · DiI-ING. J. DORNER.

e MUNICH 15

LANDWEHRSTR. 35 POST BOX 104

TEL. (08 11) 55 5719

Munich, the 2k. April 1972 Lawyer File: 33 - Pat. 8

DU-AL Corporation, 13403 Kiama. Court (Uriarwood) Laurel, Maryland 20810, United States of America

Splash-proof and leak-proof, syringe-like cryo surgical instrument.

The invention relates to cryosurgical instruments, and more particularly a syringe-proof and leak-proof, syringe-like, cryosurgical instrument for performing various cryosurgical interventions on soft tissues. In particular are devices of the type considered here for the ophthalmological cryosurgical removal of a star-affected lens from suitable for the posterior chamber.

A number of cryosurgical instruments of the type under consideration have been proposed and are in use. Among these instruments are relatively complex mechanical and electrical devices and also relatively simple instruments containing a cryogenic liquid, to be able to cool a probe to extremely low temperatures. The present invention relates to the latter called the general class of cryosurgical instruments. In particular, from US Pat. No. 3,536,076, an injection-molded and leak-proof, syringe-like cryosurgical Instrument with an elongated, for receiving a

-I-

209851/0668

Cryogenic liquid serving housing, at one end a thermally conductive working probe is held in such a way that it extends from the inside of the housing to the outside of the housing and with the cryogenic liquid is in contact and that its tip is cooled by the cryogenic liquid, furthermore with a fish trap-like Insert, its large opening near the top of the case and its wine opening inside the case lies in such a way that the cryogenic liquid enters the housing can be filled, but is prevented from leaking after filling and with means for letting the air escape from the Housing known during filling. In the US patent pen 3,536,076 is also the use of cryosurgical instruments to perform various types of cryosurgical surgical procedures and the like.

While in an instrument according to US Pat. No. 3,536 many disadvantages of previously used cryosurgical instruments especially with regard to the sensitivity of the handling of the instrument and with regard to the risk of leakage Low temperature liquids are avoided, it has been shown that further improvements can be made with which the disadvantages of known devices can be eliminated «For example it was found that the fisheus-like insert and the outer contour of the instrument according to the US patent 3,536,076 fulfill the desired functions, but improvements are possible in these parts, for example with regard to the increase in the capacity of the instrument for the cryogenic liquid and with regard to an improvement in the leakage safety when turning the instrument. Farther Although the arrangement of the working probe in the instrument according to US Pat. No. 3,536,076 is generally appropriate, however, it has been found that a slight change in the placement of the probe results in a significant improvement can be achieved when handling the instrument. Furthermore, by using a special filling cap, the splash-proof and overflow-proof Filling the cryogenic liquid into the in-

209851/0668

λ3. 222Ü828

instrument can be eased into.

The invention is therefore intended to solve the problem, a simple one and cost-saving cryosurgical instrument, which is splash-proof, leak-proof and thermally insulated, like that to train that it is particularly easy to handle and easy to fill with cryogenic liquid. The capacity should be for cryogenic liquid versus corresponding known devices are increased.

In the context of the invention, a filler cap is also to be created, those with a refill container for cryogenic liquid cooperates and the introduction of the cryogenic liquid eased into an instrument.

Starting from an instrument of the general type described briefly above and known from US Pat. No. 3,536,076 the object set is achieved according to the invention in that the housing has an upper and a lower chamber space that Furthermore, the fish trap-like insert is located in the upper chamber space is located and that the lower chamber space carries a finger-like outline having tip, through which the working probe is extends.

The upper and lower chamber spaces preferably merge into one another and the lower chamber space is thermally insulating Surrounding cladding.

The fish trap-like insert prevents the loss of low-temperature liquid, when the housing is inverted or otherwise brought from a generally vertical position.

The fish trap-like insert expediently contains a number of ribs, between which outlet channels or through channels are left free. The latter allow air to escape or gases if cryogenic liquid enters the instrument

209851/0668

ORlGiNAL INSPECTED

if 2 2 2 U 8 2 8

is filled. At its upper end is the fisheus-like Insert is essentially conical in shape, the conical part merging into a generally tubular section, which extends downwards into the interior of the housing,

Furthermore, as already indicated above, the invention creates a device which enables the introduction of the low-temperature liquid facilitated via the fish trap-like insert into the tubular housing. This facility contains a fill cap having a fill tube extending from one end of the cap. The filler cap can be attached to one end of a die Low-temperature liquid containing container are set. Will the filler cap against the the cryogenic liquid containing container is printed, the cryogenic liquid emerges from the container and flows through the filling tube. If one assumes that this is due to the fish trap-like insert is introduced, with a support on the ribs of the fish trap-like insert is given, so the cryogenic liquid flow into the tubular housing. During this filling process, a build-up of pressure is prevented because it escapes Gases can flow off via a discharge path, which by the difference between the outer diameter of the filling tube and the inside diameter of the lower portion of the tubular portion of the fisheus-like insert and through the spaces is created between the supporting ribs in the upper part of the fish trap-like insert.

Next is according to an advantageous embodiment of the invention provided that the outer part of the working probe surrounded by part of the tubular housing and under a certain Angle of preferably 45 is beveled. Appropriate a part of the housing section surrounding the working probe is also recessed, so that the rear part of the working probe exposed while the front part is covered by the case.

2Ü98S1 / 0668

INSPECTED

In an advantageous embodiment, the upper housing chamber With a larger diameter than the lower housing chamber, the two housing chambers having a conical Part merge.

From the above it can be seen that the instrument according to the invention is relatively simple and easy to use. The lower housing chamber is generally the size and shape of a injection syringe that is easy to hold and handle and then widens into the upper housing chamber, which sits between the thumb and forefinger of the surgeon, so that the cryosurgical instrument is extremely comfortable is to lead without losing sensitivity. Because of the use of mutually merging housing chambers of different sizes and a fish trap-like insert, which is located in the upper housing chamber, it is possible invert the instrument quickly or slowly without the use of cryogenic liquid can escape. Furthermore, the forward-facing surface of the metal working probe is supported by an extension of the plastic housing is covered, while the rearward-facing surface is exposed, can with the The device in the cryosurgical cataract operation has a larger area of freezing of the tissue of the eye lens can be grasped by touch, while the adjacent tissue parts of the iris are protected will. Veiter effect those provided in the fish trap-like use Ribs not only stiffen the instrument, but also form enlarged outlet channels that provide a ventilation system represent what gas and air can escape, so that a pressure build-up in the instrument during filling of Low temperature liquid is prevented.

Finally, by using a filler cap with an outwardly extending filler tube, the cryogenic liquid can be introduced deep into the instrument, creating a Splashing and leakage of cryogenic liquid on surrounding Areas or surfaces is safely avoided during the filling.

209851/0668

222U828

An embodiment of the invention is hereinafter referred to described on the attached drawing. Show it:

Figure 1 is a perspective view of the overall structure of a cryosurgical instrument according to the invention,

FIG. 2 shows an axial longitudinal section through the instrument according to FIG. 1,

Figure 3 is a perspective view of the fish trap-like insert of the instrument according to the invention,

Figure k is a partially drawn in section

Representation of a detail of the fish trap-like insert in the installed state,

FIG. 5 is a partially sectioned perspective exploded view to explain the use of an actuating filler cap according to the invention,

FIG. 6 shows a partially sectioned side view of the instrument according to the invention in an inverted position,

FIG. 7 a representation of a section through the human eye,

FIG. 8 shows a front view of the human eye with a clock face projected over it for explanatory purposes,

FIG. 9 shows a sectional representation of the human eye with the cornea lifted off in such a way that the lens affected by the cataract is accessible to the cryosurgical instrument for removal, and FIG

Figure 10 is a side view of part of the thermal

conductive working probe for the cryosurgical instrument according to the invention.

209851/0668

From Figures 1, 2 and 6 are the external shape and the overall structure an inventive instrument can be seen, which has a housing 11 with a tubular upper housing chamber 13, a tubular lower housing chamber 15 which has a lower tip substantially in the shape of a finger possesses, as well as a conical, central part 16 contains. The lower housing chamber 15 is of a thermally insulating casing 17 surrounded. The housing 11 is preferably made in one piece from a suitable, essentially thermally insulating Plastic, for example made of polypropylene or polyamide.

The finger-shaped outline having the tip of the lower housing chamber 15 ends in an essentially downwardly projecting, cylindrical section 19. This surrounds a thermally conductive working probe 21. The working probe 21 is essentially cylindrical in shape and has a fan-like inner end 23 on. The inner end 23 of the working probe 21 lies within the lower housing chamber 15 of the housing 11.

As can best be seen from Figures 1 and 6, j is the lower one The end of the cylindrical section 19 is cut out in a region 25 in such a way that the forward-facing cylindrical outer surface the working probe is covered, while the rear cylindrical outer surface of the working probe is exposed. It can be seen from FIG. 10 that the working probe 21 is at a certain angle of preferably 45 ° with respect to the longitudinal axis is beveled so that a lower, fully exposed probe surface is formed which is substantially parabolic in shape owns.

Inside the tubular, upper housing chamber 13 of the housing 11 is the fish trap-like insert 27. How to look from FIG. 3 recognizes that the fisohreusen-like insert 27 has a downwardly reaching tube 30, the walls of which are essentially closed the longitudinal axis of the upper housing chamber 13 run parallel. The downwardly pointing tube 30 goes over a conical funnel

- 7 -

209851/0668

Terminal section 29 integrally in the substantially cylindrical upper part 31 over. The outer diameter of the cylindrical top Part 31 of the fish trap-like insert 27 agrees with the Inner diameter of the cylindrical upper housing chamber 13 of the Housing 11 match. Is therefore the fish trap-like insert 27 When used in the manner shown in FIGS. 2 and 6, it adjoins the housing tightly. To the fish trap-like To be able to hold the insert 27 even more securely in the housing 11 is on the outer circumference of the cylindrical upper part 31 of the insert 27 an annular bead 33 is provided. The upwardly facing surface of the annular bead 33 is at right angles the outer surface of the cylindrical upper part 31, while the downwardly facing surface of the annular bead with the aforementioned Surface forms an acute angle. The annular bead 33 fits into a correspondingly shaped groove 35 on the inner wall of the tubular, upper housing chamber 13 of the housing 11. In addition, the upper edge of the cylindrical upper part 31 of the Fish trap-like insert 27 has an outwardly facing flange 37 which is supported against the upper end face of the upper housing chamber 13. The construction described enables insertion of the fisohreusen-like insert and prevents subsequent removal.

Furthermore, the fish trap-like insert 27 contains a number of internal ones Ribs 39 which to some extent reinforce the instrument and also in the manner to be described below present a support pool against which a filling cap is pressed can be, while at the same time venting paths for releasing gas are left free. The lower end of the Fish trap-like insert 27 ends approximately at a point at which the tubular upper housing chamber 13 in the conical middle housing part 16 merges.

From the above description it can be seen that a simple cryosurgical instrument is created by the invention, which at its upper end a fish trap-like insert

209851/0668

has and which has a thermal insulation at the lower end. The lower end is a thinner, spring-loaded section, which enables particularly sensitive and easy handling of the instrument. The lower end contains a thermally conductive one Working probe, the heat from the probe tip to the low temperature drains away fluid that is in the housing, so that the working probe is cooled. The working probe is offset from the central axis, as can be seen in the drawings is. The offset arrangement also simplifies the handling of the instrument.

It is true that a fish trap-like use facilitates that in the US patent 3,536,076, the filling is considerable the cryogenic liquid and prevents it from leaking, dooh has been found to be a simple, fish trap-like Construction does not solve all filling and leakage problems. For example, in a simple fish trap-like construction some cryogenic liquid leak or splash when filling, if the container containing the cryogenic liquid and the cryosurgical Instrument cannot be held in a certain mutual position in which the liquid immediately downwards through the fisheus-like insert into the housing is filled. If this particular position is not adhered to, some low-temperature liquid can splash and leak. It has also been shown that in the construction of the known type described at the outset, some low-temperature liquid can leak through the fish trap-like construction, when the instrument is turned over quickly. Although this disadvantage does not occur all the time, it can leak from time to time Time to occur. According to the invention, however, these difficulties become avoided. The risk of leakage during turning is essentially eliminated by the fact that a conical middle Housing section l6 is provided, which is the lower, tubular housing chamber 15 with the upper, tubular housing chamber 13 connects. The transitions formed in this way

_ Q -

209851/0668

allow the low-temperature liquid to flow in freely in the space surrounding the fish trap-like insert 27 to the liquid is in the area designated by 40 in FIG is located.

The risk of leakage or splashing during filling of cryogenic liquid is mainly carried out by the construction described in Figure 5 is eliminated. This includes an actuation and filling cap 41 with a pair according to outwardly protruding wing 43. The actuation and filling cap 41 is at its end 44 is essentially conical in shape and is otherwise essentially cylindrical in shape. A cylindrical one Opening or bore 45 remote from the conical end 44 is adapted to receive one end 46 of a container 47, which is a suitable coolant, for example dichlorodifluoromethane with 0.2 parts per thousand ethylene oxide. The end of the container 47 has an outlet opening or a valve opening 49, which with an inner cylindrical part 51 aligned, which protrudes from the conical end 44 of the filler cap 41 to the inside. The cylindrical part 51 presses against the valve opening 49 if the one containing the cryogenic liquid Container is pressed with fingers and palm or thumb against the filling cap, the fingers embracing the wings 43, while the palm or thumb rests against the container from behind. The cryogenic liquid can then from the Canister 47 flow out. While with the construction described so far, a filling of the cryogenic liquid by the fish trap-like insert 27 can be made directly into the housing 11, as in US Pat. No. 3,536,076 is described, splashing and leakage can occur during this filling process. To prevent this, one is invented improper improvement of the filling device described provided. To this end, protrudes from the center of the conical End 44 of the filler cap 41 a tube 53 away. This is so long that it passes right through the fish trap-like insert 27 protrudes into the housing 11. Although the diameter of the raw

- 10 2 09851/0668

res 53 is comparatively small, but it is large enough to remove the afterperature liquid from the container 47 in the housing 11 to flow in. The liquid is thus introduced directly into the housing 11, causing leakage and splashing is completely excluded during filling.

During the filling, a flattening surrounding the tube 53 becomes at the tip of the conical end 44 against the end faces of the Ribs 39 of the fish trap-like insert 27 are pressed. Be it notes that with this pressing due to the arrangement and shape of the ribs, the upper end of the fish trap-like insert 27 is not fully completed. In particular, it should be noted that that the ribs 39 are arranged and designed so that outlet paths arise between the ribs, duroh which during the filling process, the gas or air can escape, even if the conical end 44 of the filling cap firmly against the ribs are pressed. In addition, remains between the outer surface of the tube 53 and the inner surface of the lower, tubular Part 29 of the fish trap-like insert 27 is sufficient Space to allow gas to escape through this. An internal pressure build-up due to trapped air or evaporating coolant is prevented by this.

In a preferred embodiment of the invention, the wall thickness of the tube 53 is approximately 0.8 mm and the inner diameter of the pipe is also about 0.8 mm. Further, the distance between the outer surface of the tube 53 is from the inner surface the downwardly extending tubular part 29 of the fish trap-like insert 27 is approximately 0.8 mm. The wall thickness of the fish trap-like insert 27 is about 0.8 mm. The wall thicknesses of the entire instrument are therefore relatively small, as are the mutual distances between the parts mentioned. Nevertheless, these dimensions are sufficient to handle the cryogenic liquid to be able to introduce into the instrument and to allow the gases to escape from the instrument in the manner described. Furthermore, although the wall thickness of the fish trap-like inlet

- 11 -

209851/066 8

rate 27 is relatively low, the reinforcing ribs 39 cause additional stiffening, so that the component under Can not be compressed under the action of normal compressive forces.

It can be seen from the drawings that the fish trap-like insert 27 tapers rapidly inward to the tubular part 30, the walls of which run parallel to the inner wall of the upper housing chamber 13. This construction is different from the straight at an angle side walls of the fish trap-like Insert according to US Pat. No. 3,536,076. Due to the construction proposed here, there is a larger volume between the outer surface of the fish trap-like Insert 27 and the inner surface of the tubular, upper Housing chamber 13 of housing 11 than was the case with the instrument of US Pat. No. 3,536,076. The magnification of the volume in this area of the instrument allows the storage of a larger amount of cryogenic liquid in the instrument compared to the mentioned, known device, since this area of the instrument shows the total volume of cryogenic liquid determines that can be safely stored without the risk of leakage or splashing, when the instrument is turned over quickly.

Another notable property of the invention Instrument is clear from Figure 2. Since the end of the instrument on the probe side has the shape of a finger, there is a large part of the inner surface of the working probe 21 is in contact with the cryogenic liquid in the housing, so that the working probe tip is better cooled. Due to the finger-shaped outline and the location of the probe namely, a recessed area or depression 55 is formed around the working probe. The cryogenic liquid or Because of this design, the liquefied gas is always forced to flow towards the working probe 21. The deepened Area or trough 55 increases the contact time between

- 12 -

2098S1 / 0668

Working probe and cryogenic fluid, so that for cryosurgical Interventions, more time is available than would result if the deepened area were not intended.

As indicated in Figure 2, a part of the cylindrical outer surface of the working probe 21 can expediently with a thread be provided so that a good seal between the working probe 21 and the cylindrical part 19 of the housing 11 is achieved will. For this purpose, the cylindrical part 19 can be inserted into the threads under the action of heat in order to produce a good seal with respect to the threads be shrunk. It should also be noted that the angle which the fan-shaped part 23 of the working probe forms with the longitudinal axis of the instrument, preferably is equal to the angle which the lower surface of the working probe encloses with respect to the longitudinal axis. So this angle is also 45.

After the above description of a preferred embodiment of the cryosurgical instrument according to the invention will now briefly be based on the use of such an instrument an ophthalmological operation, in which a cataract lens is removed from the posterior chamber of the eye Eye is detached by a cryosurgical procedure. FIG. 7 shows a vertical section of the human eye from FIG Side seen. The lens 63 of the eye is connected to the ciliary body 65 via the zone threads 67. On the one facing forward Surface of the lens 63 lies in the anterior chamber of the eye, the is formed between the cornea 6l and the pupil, the iris 69. The cornea is covered by an epithelial layer 73, which is the continuation of the horny layer of the conjunctiva 75.

Figure 8 is a front view of the eye Th of Figure 7 with a dial projected thereover for purposes of explanation. The twelve o'clock position is directly above the eye in the direction of the eyebrow, the three o'clock position is to the right of the eye, the six o'clock position is below the eye and the

" ¹³ " ORIGINAL IMSPEGTED

20985 1/0668

The nine o'clock position is on the left side of the eye.

During the operation to remove the cataract lens, the surgeon brings the working probe of the cryosurgical Instrument from the twelve o'clock position, d. h., from Part of the head, into the eye. The tip of the working probe hits the star-infested lens either at the Three o'clock position or at the nine o'clock position, there on these Make the greatest touch of the strongest parts of the lens tissue possible with the parabolic working surface of the working probe is. In addition, these locations are chosen because the oval shape of the tip of the working probe looks best this way adapts to the thicker tissue areas on the outer edge of the lens, where the lens is firmly attached to the zone threads 6? is held. As already previously mentioned, when the cylindrical tip of the working probe is beveled at a certain angle, the result is a parabolic one or elliptical bottom surface, the sides of the ellipse are longer than the top or bottom of the ellipse. Will therefore If the tip of the working probe is brought into either the three o'clock position or the nine o'clock position, the largest parts of the circumference are located the tip of the working probe near the zone threads. If the working probe would either be in the six o'clock position or bring the twelve o'clock position, so only the smallest turns * - catching parts of the tip of the working probe near the zone threads.

In any case, the cornea and the epithelial layer on it are normally used before the insertion of the working probe a normal, not shown instrument along the conjunctival border. The cornea and the The epithelial layer is lifted off in the manner shown in FIG. 9, so that the anterior chamber is exposed. The iris is voilsfcan-

otan

dig withdrawn or widened what / by repeated instillation A suitable solution is achieved in the conjunctival sac of the eye prior to surgery. After that, the top of the Working probe of the cryosurgical instrument to the surface

-IA-

2Ü985 1/0668 ORIGINAL "* oP £ CTEp

AS

before the cataract lens either in the three o'clock position or put on in the nine o'clock position. As soon as the tip of the working probe comes into contact with the lens, the lens tissue forms a small ball of ice around the contact surface of the working probe, creating a strong bond or adhesion between the star-infested lens and the tip of the working probe. The tip of the working probe is then inserted into the pulled four directions to detach the lens from the zone filaments such that the cataract lens is cryoextracted can be removed. It should be noted that due to the exposure of the rear area 25 of the working probe in the way described here larger ice balls of the lens tissue are possible and thus a better adhesion is achieved, as if the rear area of the working probe were not exposed. But after three quarters of the parts of the When the tip of the working probe is covered, the working surface of the probe is prevented from sticking to other parts of the eye.

It can be seen from the above description that the invention provides an improved, syringe-like, syringe-proof and leak-proof cryosurgical instrument is created, the size of the instrument is selected such that the instrument how a hypodermic syringe the length of a fountain pen can be easily handled. At an ophthalmologist surgical interventions can therefore be carried out very precisely by the surgeon and other medical interventions be made in which a cryo-extractor can be used.

The invention not only helps address the disadvantages known so far Avoiding instruments of the kind considered here, but also brings an improvement over instruments according to the US Pat. No. 3,536,076. In particular, it should be noted that in the instrument according to the invention a larger volume of Refrigerant can be accommodated as a fish trap-like Use is provided that has a larger space between this

- 15 -

20985 1/0668

2220 J 28

Insert and the housing walls exposed. Furthermore, splashing or leakage occurs with the instrument according to the invention of filling in low temperature! Jerkiness through use a new actuation and filling cap in connection with a container in which the Tielteraperaturlösung is avoided is located. The ones provided in the fish trap-like insert Ribs allow the outflow of gases, so that an internal pressure build-up in the instrument is avoided. Finally allowed the training with a longer, upper chamber space and a smaller, lower chamber space with a conical Middle section a quick turn around of the fountain pen-like or syringe-like housing without leakage of the cryogenic liquid in the instrument.

Within the scope of the invention, there is still a large number of options available to the person skilled in the art of further training and modification opportunities. For example, while in the present embodiment, four ribs of the fish trap-like insert are shown and described, a larger or smaller number of ribs is also possible. In addition, certain dimensions can be compared to the specified Values are changed.

16 -

20985 Ί / 0668 ORIGfNALfNSPECTED

Claims (9)

222U828 claims 1. Injection-proof and leak-proof, syringe-like cryosurgical Instrument with an elongated housing serving to hold a low-temperature liquid, on one of which The end of a thermally conductive working probe is held so that it extends from the inside of the housing to the outside of the housing and with the Low temperature liquid is in contact and that its tip is cooled by the low temperature liquid, furthermore with a fish trap-like insert, the large opening of which is close to the upper one End of the housing and its small opening inside the housing lies in such a way that the cryogenic liquid can be filled into the housing, but after filling it, it leaks is prevented and with means for deflating the air from the housing during filling, characterized in that the Housing (ll) an upper (13) and a lower chamber space (15) has that the fish trap-like insert (27) is in the upper Chamber space is located and that the lower chamber space is a finger-like Outlined tip carries through which the working probe (2l) extends " 2. Instrument according to claim 1, characterized in that the Fish trap-like insert (27), an upper part (31), a tubular, downward-reaching part (30), which opposite the Upper part has a smaller diameter, as well as a conical section (29) connecting these two parts. having. 3. Instrument according to claim 1 or 2, characterized in that the fish trap-like insert (27) or its upper part (3i) - 17 - 209851/0668 contains several reinforcing ribs (29) parallel to the longitudinal axis of the fish trap-like insert. 4. Instrument according to one of claims i to 3, characterized in that that the upper chamber space (13) and the lower chamber space (15) have a cylindrical shape, the lower chamber space having a smaller diameter than the upper chamber space and that the two chamber spaces are connected to one another by a conical central part (16). 5. Instrument according to one of claims 1 to 4, characterized in that that the lower chamber space (15) with a thermally insulating Casing (17) is provided and that at the end of the lower chamber space around the inner end (23) of the working probe (21) around a depression or recess (55) is formed. 6. Instrument according to one of claims 1 to 5, characterized in that that the lower end (19) of the lower chamber space (15) of the housing (II) is extended outward and surrounds the working probe (2i) in such a way that essentially only the tip the working probe is exposed. 7. Instrument according to claim 6, characterized in that a rear region of the part surrounding the working probe (21) (19) of the lower chamber space (15) is cut out, so that a rearward-facing part (25) of the working probe (21) is exposed. 8. Actuating and filling device for filling a cryogenic liquid in an instrument, in particular in an instrument according to one of claims 1 to 7, characterized by a substantially cylindrical cap (41) which fits onto the outlet end (46) of a cryogenic liquid containing Container (47) can be placed and actuating means (50 to operate the container in the sense of a delivery of low-temperature f contains liquid, as well as through a filling pipe (53) wel- - 18 - 209851/06 68 ches from
temperate 9. Setup
outer that (ji ^ pppi ^^ - ^ J ₁ OJiλ contain, " the GE? _ _Λ ν masi! Opening (49) of the container (47) andrückuctx 'on which the conical end (44) of the cap (41) opposite side is arranged within the cap and with the filling tube (53) such connection that of the container discharged cryogenic liquid is fed into the filling tube will. - 19 - 20985 1/0668