CA1038251A

CA1038251A - Medical aspiration system, and method

Info

Publication number: CA1038251A
Application number: CA171,924A
Authority: CA
Inventors: Henry Bridgman
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-06-02
Filing date: 1973-05-22
Publication date: 1978-09-12
Also published as: US3833000A; BE800059A; FR2186215A1; JPS4943483A; FR2186215B1; JPS5621421B2; DE2326178A1; CH582005A5; GB1417800A

Abstract

MEDICAL ASPIRATION SYSTEM, AND METHOD

ABSRRACT OF THE DISCLOSURE

A medical vacuum aspiration system preferably for use in vacuum abortions and diagnostics. The system is designed for operation at high vacuum and includes a single transparent container which provides the reservoir of vacuum, the chamber for collecting the aspirated products, a trap for the collection of tissue and the handle for the cannula. The container is provided with a cap and valve on which the cannula is directly mounted. The invention also includes a preferred method for producing high vacuum inside of the chamber.

Description

1038~51 The invention relates generally to medical as~iration equipment. The invention will find particular application in uterine aspiration such as for vacuum abortions or sampling of tissue for endometrial cancer detection.
Within the past seventeen years a technique called uterine aspiration or vacuum curettage has been developed for performing abortions during the early months of pregnancy. The earliest reference to this technique appeared in an article by Y.T. Wu and H.C. Wu, entitled "Suction in Artificial Abortion-300 Cases" in the Chinese Journal of Obstetrics and Gynecology, Vol.6, 1958, beginning at page 447. A recent survey of the subject appeared in an article by Kerslake and Casey, entitled, "Abortion Induced by Means of Uterine Aspirator" in Obstetrics and Gynecology, Vol. 30, July, 1967, pages 35-45. Very briefly, the technique described in the Kerslake and Casey article is to aspirate the conceptus from the uterus using a tube which has a flexible connection to a source of suction. A typical apparatus as described in the article includes a suction curette having an oval mouth at its end, or on one side, and an air hole at the other end to control the suction. A
rubber suction tubing connects the curette to a glass container which in turn is connected to a source of suction. Aspiration of the uterine contents usually takes less than two minutes and the fetal material can readily be seen as it appears in - the glass container. The method employed may be very brie~ly reviewed. The perineum, vagina, and cervix are disinfected.
The cervix is then drawn forward with a tenaculum.
The direction of the cervical canal and the depths of the '`~

1~3~2S1 uterine cavity are determined with a uterine sound. It is a common practice to dilate the cervix to allow easy insertion of the suction curette. When dilution is required, preferably a local anesthesia is administered. General anesthesia is rarely used. The suction curette of appropriate diameter and design is inserted carefully through the cervix into the uterus. The suction is then started. In a few seconds the suction reaches a working level which, according to the Kerslake and Casey article, i~ at a mean level of 18 inches of mercury (relative). The suction curette is moved gently up and down over all aspects of the uterine cavity.
The products of conception pass visibly into the glass con-tainer either whole or piecemeal. The degree of suction can be controlled with some aspirators by putting a thumb over an airhole at the base of the curette as well as by using a pressure control device on the pump. During the aspiration process, the uterus reacts by contracting and decreasing in volume. Aspiration usually takes less than a minute or two. It is thought to be complete when the uterine wall feels smooth and no further remnants emerge.
` A typical prior art apparatus used for uterine aspiration consists of a curette connected by a hose to a collection - bottle which in turn is connected by a second hose to a vacuum source.
In the prior art system described by Kerslake and Casey the source of the vacuum or suction, the collection bottle, and the curette or cannula, are connected by hoses or pressure tubing. The working level of vacuum or suction ` typically is 15 to 18 inches of mercury (relative) and is gradually raised to this level after the curette is inserted into the uterus.

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~03~2S~
Uterine aspiration, is not limited to abortions, ~ but is a general technique with a further application in diagnostics. For example, in a recent article by B.A. Bjerre, et al, entitled "Aspiration Curettage -- a New Diagnostic Method" in the Journal of Reproductive Medicine Vol. 7, No.
5, ~ovember, 1971, the technique of aspiration curettage was recommended for routine use in collecting tissue for endometrial diagnosis and other diagnostic purposes. Here the curette is of a small outside diameter, typically 3mm, welded to a plastic cap of a tubular chamber which in turn - is connected to a suction pump. The plastic chamber contains a perforated plastic cylinder that serves as a filter and arrests mucosal fragments which are to be laboratory tested for either polyps, endometrial "atypia", or an adenocarcinoma. The technique employed in the diagnostic aspiration curettage is similar to that employed for the abortions by vacuum curettage. Here the vagina and portico are cleaned, typically with soap. The portico is gripped with a tenacucoum forceps; a uterine sound is passed in the cervix and without further dilation the curette is advanced into the fundus. Suction is introduced and the curette is passed over the entire uterine wall; tissue and some blood is scraped from the uterine wall and aspirated by suction.
The tissue is trapped in the tubular chamber and a histopathological examination is subsequently done on the aspirated and trapped tissue.
In one embodiment of the present invention a high vacuum is used, e.g. 28 to 30 inches of mercury, which is applied with full strength at the very beginning of the procedure. By using this high vacuum, it is possible to lQ382Sl construct an aspiration system in which the collection bottle,source of vacuum, and handle for the curette are all one.
This does away witha separate source of suction, whether that be an electric pump (which is commonly used in the United States), or a vacuum jar (as used in China). It might be noted that electric pumps are subject to failure -- due to electrical interruptions, or to accidental carry-over of fluids from the collection bottle -- with the very serious consequence that the procedure is interrupted and has to be completed by sharp D & C or in extreme cases by a hysterectomy. The system, moreover, does away with the prior art hoses which connect the curette to the collection bottle and the collectionbottle to the suction source.
These hoses encumber the physician. Furthermore, if the curette is not provided with a handle and swivel, which are heavy, it is difficult to rotate the curette in the uterus. This feature is considered very desirable by many surgeons. In the present system there are no emcumbering ; hoses, and the surgeon may rotate the curette easily without heavy swivels or other attachments.
In one embodiment of the invention, a high vacuum is induced in a transparent bottle typically less than one-half liter in volume. A cap with a valve is mounted on this bottle and a cannula or curette rigidly fits into a seat on the valve. In a typical procedure, the cannula is introduced into the uterus, the valve is then opened and -~ the full vacuum rapidly sucks the products of conception from the interior of the uterus. The surgeon may grasp the bottle in one or both of his hands and move the cannula tip over the wall of the uterus. The valve is then closed, lQ38~'Sl and the apparatus is withdrawn.
It will be noted that the apparatus is relatively small. The volume of a typical bottle is 0.35 liters, small enough to be conveniently held in a surgeon's hand. This size is possible because of (1) the initial high vacuum and ~2) the absence of hoses, which dilute residual vacuum by reason of expansion, and (3) the discovery that the material extracted from the uterus is a fluid with virtually no gas content. The latter point might be examined a little more fully. The products of conception extracted from the uterus is a fluid with entrained semi-solids. This apparently was not previously ap~reciated, nor was it applied to the practical design of uterine aspiration apparatus. Experimen-tation has confirmed that the collection bottle may be filled approximately 70% full with aspirated material before the pre-induced vacuum leval falls more than 12%. (In one measurement, a 475 milliliter container starting with an initial vacuum of 28.64 inches of mercury was filled to 400 milliliters and had a remaining vacuum of 26.85 inches of mercury. When subsequently filled to 450 milliliters, it still had 23,34 inches of mercury vacuum). The important point is that it is not until the aspirated volume reaches - about 70~ of collection bottle volume that the initial induced vacuum begins to deteriorate, appreciately. This fact apparently had not been appreciated nor was it applied ; heretofore to uterine aspiration systems.
A further advantage of this system is that the aspirated products may be easily observed by the physician because the collection bottle is attached directly to the - 30 cannula and is in his hand during the procedure. In prior 1~38Z5~
art abortion systems the collection bottle is remotely positioned. When connected by a hose, the collection bottle --in order to avoid being accidentally toppled over when the hose was pulled on -- is securely mounted onto a stable platform which is usua~ly some distance away and the physician has to look up and away from the patient and the point of operation to see the aspirated material. With the apparatus of the present invention, the doctor applies his sense of touch to the collection bottle, and also concen-trates visually on the collection bottle to observe theproducts of conception being removed.
A further advantage, is lack of dependence on the electric vacuum pump. In addition to mechanical failure, possible contamination, and electric power failure, the pump has the further drawback in that its noise is psychologic-; ally upsetting and stress-producing on the patient. It has been observed that when the pump is turned on and running, the patient reacts with an undesirable tension, complicating the emotional, as well as the physical completion of the

2~ operation. The system it will be noted is completely silent.
It may be noted that this embodiment of the - inventionhas the further advantages of being compact in that - it occupies but a small volume, and it is simple to assemble, disassemble and clean as well as to operate.
- The initial vacuum in the bottle of this system may be induced by an electric pump, or by any other mechanical means. A preferred method of producing a very high vacuum, e.g. 28-30 inches of mercury in the collection bottle itself includes the steps of placing a small amount of water inside the bottle, heat ng the water so as to cause -1~38251 it to boil and fill the jar with saturated steam, thereby driving the entrapped air out of the bottle, then closing the valve on the bottlecap to trap the steam, and then cooling the steam and bottle. As the steam condenses a nearly perfect vacuum is produced. This method may be employed in those areas where electric or mechanical pumps are inconvenient or untenable. It may find particular application in emergency situ~tions, or in areas where electricity of appro-- priate characteristic is unavailable. The only requirement for producing high vacuum by this method is enough heat to boil water. It may be further noted that this preferred method sterilizes the collection bottle, as well as the valve fitting through whi~h the steam is passing.

1~138~S~
When the thermodynamic method of forming a high vacuum is used~ the apparatus may include a relief value for permitting the steam to escape, and various modifications and embodiments of such relief valves are described herein.
A further aspect is a novel filter or trap for collecting the semi-solid parts extracted during an aspiration.
The novel trap has the advantage of both a flexible trap, as well as a rigid trap. The advantages of the former are that it can be easily emptied so that the solid parts may be spread out in a pan to perform the fetal parts count. The novel trap may be disconnected and set aside should the surgeon decide that he does not wish to use a trap.
The novel trap is particularly useful with the high vacuum available with the apparatus of this invention ` in that the solid and liquid parts are drawn into the collection bottle at a high velocity, thereby moving the solid parts into the bottom of the trap and away from the entrance to the collection bottle.
:- .
According to one aspect of this invention, a vacuum curettage aspiration system for removing semisolids or fluids and tissue from a uterus comprising a collection bottle; a cap connectable to said bottle; and an operator-operative valve mounted in said cap and having a seat for receiving a cannula, said valve providing on/off flow through passage from said cannula receiving seat to the interior of said bottle said passage of said valve being sufficiently large to permit, during a surgical procedure, said semisolids or fluids and tissue from the uterus to pass from said cannula into said bottle.
Objects and features of the invention disclosed will become apparent to those skilled in the art upon reference to the following specifications and accompanying drawings wherein several embodiments are disclosed by way of illustration.
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1~38~
IN THE DRAWINGS
Figure 1 is a plan view of a preferred embodiment of the invention, and auxiliary apparatus that may be used therewith.
Figure 2 is a perspective view of a partially assembled trap for use in the apparatus of Figure 1.
Figure 3 is a graph illustrating the relation between pressure (vacuum) remaining in the bottle in terms of fluid volume aspirated.
Figure 4 is a perspective view of an alternative embodiment of a portion of the cap valve socket assembly of Figure 1.
Figure 5 is a cross sectional view of a detail of -~ the assembly of Figure 4.
DESCRIPTION OF EMBODIMENTS
Referring now to the drawing of Figure 1, there is shown a preferred embodiment of a collection apparatus of the invention, which will find typical application in ` terminating early pregnancies. The appa~atus consists basically of three parts: a collection vacuum bottle, 10, a cap valve socket assembly, 12, and a mesh filter or trap, 14. A cannula, 16, fits directly into asocket connection on the cap valve socket assembly, 12. Two accessories are also shown in Figure 1. The first is a floating relief and check valve, 18, which may be used when the vacuum n the collection bottle is to be produced thermodynamically, as described more fully below. The second, is a test gauge, 20, to measure the vacuum in the collection bo~tle, and which is more fully described below.
The collection bottle itself, 10, is preferably ,~ - 10 -~38251 made of a clear (i.e. transparent) heat resistent material (e.g. Pyrex) (trademark). The dimensions of the collection bottle are such that it may be conveniently hand-held. A
preferred bottle has a lower portion, 22, which is larger than its upper portion, 24. A checkered or textured surface, 26, may be provided on the lower portion, 22, of the bottle, to facilitate gripping. A typical bottle is 6-1/2 inches long, with the upper portion 2-1/4 inches in diameter and the lower portion 2-1/2 to 3 inches in diameter. During a pro-cedure the bottle is held in one hand and manipulated.Alternatively, the surgeon may loosely hold the upper portion - in one hand, and grasps the lower portion with his other - hand, swivelling the apparatus so as to move the cannula ; tip over the wall of the uterus. It should be noted that the assembled apparatus includes the cannula rigidly connected to the collection bottle so that the bottle in addition to being the collection chamber, and the reservoir of the vacuum, is also the handle for the cannula. It should be further noted that the collection bottle during the procedure is in the hands of the SurgeQn and the extracted products of conception can be readily viewed through its transparent walls by the doctor as he performs the operation.
; The upper end of the bottle terminates in a screw fitting, 28, which mechanically mates with a corresponding fitting on the cap valve socket assembly, 12. It should be understood, however, that any convenient or conventional fitting may be used so long as the connection is vacuum -tight, and for certain embodiments, are also heat resistant.
The cap valve socket assembly, 12, includes a cap portion, 30, which connects to the screw thread, 28, on lQ3~
the upper portion of the bottle. A plug valve, 32, is mounted on the cap, 30, and terminates in a suction curette socket connection, 34. The cannula or curette, 16, fits directly into the socket connection , 34, and i5 secured tightly therein by either a friction fit, as is common with many curettes commer-cially available~or by any other convenient or conventional securing means. The plug valve, 34, includes a handle, 36, which is movable between first and second positions, to permit, or to block, a freeflow having at least 3/8 inches diameter passage from the socket connection at 34, to the interior of the bottle at the inside of the cap, 30.
The mesh filter or trap, 14, may be a rigid plastic or metal mesh strainer which fits inside the collection bottle, and may be attached oither to the inner face of the cap, or along the interspace between the cap and the top lip of the bottle. In practice, the traps collect the fetal parts and other solid material which are subsequently examined by the surgeon or pathologist. In the case of endometrial tissue colle¢tion, it is this tissue material which is sought for the subsequent diagnostic testing. In the case of abortion the semi-solid material is examined to make sure all of the products of conception have been removed.
- A preferred trap, constructed in accordance with - this invention, is shown in perspective, partially assembled, in Figure 2.
The trap includes a transparent cylindrical tube, 40, opened at both ends, and provided with an outwardly pro-truding lip, 42, at its upper edge. A tube receiving clip, 44, is mounted on the inside of the cap, 30, encircling the lower end of the flow through passage, and shown here as 46.

lQ38251 The clip, 44, may be a resilient plastic which engages and firmly grips the lip, 42, on the tube, 40, thus riqidly holding the tube onto the cap, 30. A loosely woven tubular-shaped fabric, 48, open at its upper end, and closed at its lower end, is positioned inside the tube, 40. The upper end is is folded over the upper lip, 42, extending approximately a half an inch down from the top. The fabric, 48, is held in place by either the natural spring of the fabric itself, or by a rubber band or piece of string around the folded over fabric. The`tube with the fabric over its upper end fits onto the receiving clip, 44, on the ca~.
` The lower end of the fabric which is closed extends past the lower end of the tube. During an operation, solid matter which is aspirated, is retained in the fabric, 48, while liquid readily passes therethrough. With this arrangement the advan-tages of bcth the flexible and rigid collection traps are achieved. The tube, 40, holds the fabric, 48, in the proper spacial position inside the bottle, while preventing both clogging of the inside of the flow through passage by the fabric and accumulation of collected material at the passage ` opening, 46. The aspirated solids are in the flexible fabric, 48, and the surgeon -- after he believes all the products of conception have been aspirated, but while the patient is still in the operating room -- may open the collection bottle, snap off the tube, 40, with the fabric, 48, pull out the fabric, 48, and turn it inside out, thus very rapidly freeing all the solid material. The fetal parts count is then performed, with the surgeon determining whether all material has been extracted, and if necessary, he can go back - 30 and remove any remnants which were missed. The speed with :

10~51 which the filter can be emptied, coupled with the structure that does not clog the filter, are thought to be important.
In a typical procedure, the trap, 14, is connected and the cap assembly, 12, is attached to the bottle, 10 (with the handle, 36, in the open position). Vacuum is induced inside the bottle, 10, the handle, 36, is closed. A sterile cannula, 16, is fitted into the socket, 34, and the apparatus is ready for the procedure. After the patient has been prepared, the cannula is introduced into the uterus, and the surgeon opens the valve, 34, at the handle, 36; and then, - by manipulating the bottle, 10, with one or both hands, moves the opened end of the cannula overithe surface of the uterùs wall, extracting the conceptus. When all the material is believed to be removed, the handle, 36, is closed, and the apparatus is removed. In the case of endometrial tissue !:: :;
^~ extraction, a similar routine is followed.
The vacuum inside the bottle, 10, may be produced immediately before the operation, by an electrical or mechanical pump' Alternatively the apparatus may be vacuum pre-pa;ckaged with the vacuum induced several weeks or months before the procedure and the apparatus rests on the shelf until ready.
In a preferred method, the vacuum is produced thermodynamically and preferably shortly before the operation.
The advantages of the thermodynamic process are many. First, a very high vacuum is obtainable, on the order of 28 to 30 inches of mercury (relative). Second, the technique sterilizes the entire apparatus. Third, the vacuum may be produced without the need for an external pump whether that pump be electrical or mechanical, and thus does not rely upon -~ - 14 -lV38~51 electrical power or a source of mechanical power. According to the preferred method, the valve cap socket assembly, 12, with the attached trap, 14, is separated from the bottle, 10, and several cubic centimeters of water (e.g. 2 to 4 cc's) are placed inside the bottle. The trap, 14, and socket assembly, 12, are replaced, and the handle, 36, is in the open position. Heat is applied to the bottle, 10, until the water inside boils and steam issues steadily from the curette socket, 34. At this point the apparatus is removed from the heat and the handle, 36, is quickly closed. As the assembly cools the condensing steam induces the high vacuum inside the bottle, 10. The saturated steam produced during heating drives out the entrained air, and the steam when cooled, condenses to a very small volume, producing a very high vacuum. The heat may be provided from any source, such as a laboratory Bunsen Burner, an autoclave, or if used in the field, a portable heating source, such as a STERNO
; (trademark) heater, or a kitchen stove.
It has been discovered that the aspirated products have very little, if any, gaseous content, and the high vacuum pre-induced inside the collection bottle remains relatively stable until approximately 70% has been filled with liquid and semi-solid material. For example, with an initial vacuum of 28.43 inches of mercury a collection --l bottle was filled 73~ full and the remaining vacuum was still 25 inches of mercury.
The relationship can be generalized and expressed -~ mathematically as follows:

PaVf + Ps(V-Va) Ir = Vf + (V-Va) 1~38ZSl where Pr = Pressure (vacuum remaining in collection bottle for any amount of fluid volume aspirated).
Ps = ~nitial pressure in collection bottle (pre-induced vacuum).
Pa = Atmospheric pressure.
V = Volume of collection bottle.
Vf = Free volume between suction tip opening and valve.
Va = Fluid volume aspirated.
All Expressed in Absolute Units.
In the apparatus the quantity Vf (the free volume between the suction tip opening on the cannula and the valve) ; is held to a minimum because there are neither hoses nor intermediate connections between the cannula and the valve to deplete the available vacuum. When Pr, (the vacuum remaining in the collection bottle) is expressed in terms of Va (the fluid volume aspirated) for any set of given conditions, it is found that Pr does not change appreciably until the fluid volume aspirated reaches about 70% of the collection bottle volume. Thus, relatively large volumes of fluid may be aspirated at nearly constant pre-induced vacuum levels. This relatîonship is shown graphically in Fi~ure 3.
When the vacuum is produced thermodynamically, various modifications may be added to the apparatus. Figure 1 shows the floating relief and check valve, 18, which fits into the socket connection, 34, and is placed in the socket connection, 34, just before the bottle is heated. The valve, 18, is of sufficient weight to remain in the recessed ;

i~38ZSl socket connection yet allow entrained air and steam to escape during the heating cycle. When the heat is discon-tinued, and the steam condenses, the valve, 18, is drawn tightly into the socket, 34, by vacuum, and air is prevented from entering the bottle. The apparatus is then cooled, the handle, 36, is closed, and the valve, 18, is removed.
With this arrangement, the valve, 18, closes at the right moment, and an attendant does not have to handle the appar-atus while it is hot.
An alternative embodiment relief valve is shown in Figure 4, which is a perspective view of a portion of the cap valve socket assembly. The handle, 36, is connected to a rotable spool, 50, which has first and second passageways, 52 and 54. The first passageway, 52, becomes aligned with a central passageway (flow through) of the plug valve, 32, when the handle, 36, is in the open position (as '.
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:: -'-:

3~

sh~n in this Fi~,ure)~ The second pas~ageway, 54, is perpendicular to the first passageway and extends to one side of the spool, where a one~way valve, 56, is mounted in the side wall or housing of the valve, 32. This one-way valve~
56, is of a kind which permits passage of a low pressure air and steam from the inside of the housing to the outside of the housing, but which blocks the passage of air in the opposite direction. A detail of a cross-section of the one;way valve, 56, is shown in Figure 5, and includes a spring loaded ball, 58, which presses against a seat or collar, 60. The one-way valve, 56, is of a conventional design and any other one-way valves which perform the same function may be used. ~The advantage of the valve arrangement of Figures 4 and 5 is that when steam is generated and the valve, 32, is in its closed position, (i.e. the handle, 36, rotated90 downward and forward in the direction of Figure 4 so that the spool 50 takes the -position shown in Figure 5) the steam and entrained air will pass through the second passageway, 54, into the large passageway, - 52, and then through the one-way valve, 56. ~hen the apparatus is cooled, the one~way valve, 56, will not permit the return ~-of air and the bottle is thus effectively sealed and as the steam condenses, the vacuum builds. It is not necessary for an attendant to handle the hot apparatus, or close the hot valve.
A further accessory for use with the apparatus is - shown in Figure 1. It is the vacuum test gauge, 20, which . has a conventional vacnn~ ga~ge, 70, ,' /~

; ' 10382Sl connected to a lower mating plug, 72, which f its into the socket, 34. The available vacuum can be measured without the loss of any pressure, (oth~r than the vacuum associated with the gauge, 20, which is negligable) by placing the plug, 72, in the socket, 34, and opening the handle, 36. The gauge, 20, is also provided with a bleeder control knob, 74, which permits the controlled introduction of ambient air into the collection bottle. With this arrangement the vacuum inside the bottle may be adjusted to a lower level, if desired, while monitoring the remaining pressure on the gauge, 70.
An alternative gauge, 80, is shown in Figure 1.
It will find particular applica-tion with pre-packaged vacuums that may remain on the shelf for several weeks or months. Gauge 80, is a non-porous elastic membrane, filled wi~h a given quantity of gas. It is positioned inside the - bottle, 10. When there is vacuum in the bottle, the membrane is completely inflated through the expansion of entrapped air sealed in at atmospheric pressure. As the vacuum decreases, the membrane correspondingly collapses.
Thus, the size of the membrane, 80, provides a rough indication of the amount of vacuum remaining in the bottle.
During a procedure, as the vacuum bottle fills, the gauge, i 80, provides a continuous measure of remaining vacuum.
, This is possible because it is light and floats on top of any collected liquids, and is always readily visible.
Although ~mbodiments of the invention have been described with examples applicable to abortions, it is not .
- so limited, and may find application elsewhere. For example, where the apparatus is to be used for endometrial cancer detection, or for removal of cysts and drain other body cavities, different sized cannula, and different sized collection bottles may be used. For example for endo-metrial testing the cannula typically has an outside diameter of 3 mm (this may be contrasted with the cannula used in the early weeks of pregnancy of approximately 6 to 8 mm) and the collection bottle is small in size, typically having a volurne of about 100 ml.
Thus there has been shown and described a uterine aspiration system which is self-contained, easy to use and frees the doctor from the encumbrances of connecting hoses, swivels, etc. Furthermore, the collection bottle forms the "handle" of the curette and thus not only provides a good support, but also permits inspection of the extracted products during the procedure. The apparatus moreover, does not depend upon an electric pump as its source of vacuum during the operation, and thus is free fro~ the noise, and the resulting phychological stress associated ~herewith and possibility of power failure. There has also been explained . .
that it is possible to perform the vacuum curettage with a relatively small volume high vacuum collection bottle.
~; There has also been described a preferred method of producing the high vacuum. This method does n~t rely upon electric pumps or mechanical pumps, and may be produced in areas where electricity, and machinery, is not available.
The method is simple, and also sterilizes the equipment. It will find particular application in remote areas of the world, where electricity and electric pumps are not readily available. There has also been described various gauges, and accessory valves, for use with the apparatus.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A vacuum curettage aspiration system for removing semisolids or fluids and tissue from a uterus comprising a collection bottle; a cap connectable to said bottle; and an operator-operative valve mounted in said cap and having a seat for receiving a cannula, said valve providing on/off flow through passage from said cannula receiving seat to the interior of said bottle said passage of said valve being sufficiently large to permit, during a surgical procedure, said semisolids or fluids and tissue from the uterus to pass from said cannula into said bottle.

2. A system according to claim 1 wherein said bottle has a volume capacity between 100 and 500 milliliters.

3. A system according to claim 1 wherein said system further includes a one-way relief valve means for permitting the passage of entrapped air and steam from the bottle into the ambient atmosphere.

4. An apparatus according to claim 3 wherein said one-way relief valve means comprises a weighted check of such dimensions that it fits into said cannula receiving seat, whereby when said apparatus with the valve open is slightly filled with water and heated and steam is generated inside said bottle, said steam pushes entrapped air and steam against said weighted check and escapes, and when said apparatus is cooled, said weighted check is drawn tightly closed by atmospheric pressure through condensation of the steam inside said bottle.

5. A system according to claim 3 wherein said operator-operative valve has a housing with a central passageway extending from inside said cap to said cannula receiving seat, a transverse bore intersecting said central passageway, a spool rotatably mounted in said transverse bore having first and second passageways, and a handle connected to said spool for operator-operatively moving said rotatable spool between a first and second position;
said one-way relief valve means includes a one-way valve connection extending from said transverse bore through said housing, said one-way valve permitting a uni-directional passage of gasses from said transverse bore to an outside of said housing; and said first passageway of said spool having a diameter equal to, and having its axis coplanar with the axis of said central passageway, and providing said open flow through passage from said cannula receiving seat to said bottle interior with said rotatable spool in said first position, and blocking said flow-through passage when in said second position;
said second passageway of said spool extending from said first passageway to a side of said rotatable spool and providing another flow through passage from said inside of said bottle through said first passageway and said one-way valve to the outside of the housing with said rotatable spool in said second position.

6. An apparatus according to claim 5 wherein the axis of said central passageway, said transverse bore and said one-way valve are perpendicular to one another.

7. An apparatus according to claim 1 wherein said collection bottle is made of a transparent material, and has such cross-sectional and length dimensions that it may be readily manipulated by one hand.

8. An apparatus according to claim 1 wherein said bottle has a smooth cylindrical neck portion adjacent to said cap, about 2 inches in diameter, and 2 to 3 inches in length;
and a body portion about 2-1/2 and 3-1/2 inches in diameter and 3 inches in length with a textured outer surface to facilitate gripping. 22

9. An apparatus according to claim 1 further comprising a tissue trap assembly mounted inside said collection bottle at one opening of said operator-operative valve.

10. An apparatus according to claim 9 wherein said tissue trap assembly includes a snap connection on the inside of said cap; a transparent tube connectable to said snap connection and extending into said bottle; and a gauze sleeve longer than said tube and extending therethrough, one end of said sleeve being folded over said snap connectable end of said tube and another end of said sleeve being closed and protruding from the opposite end of said tube.

11. A system according to claim 1 further comprising a negative pressure gauge for measuring the vacuum in said system having an input valve received in said cannula receiving seat and of such dimensions to hermetically fit in said seat, the gauge measuring the vacuum in said bottle by opening said valve and further comprising an operator-operative bleeder for permitting the passage of air into said vacuum bottle to lower residual vacuum level while measuring the vacuum in said bottle.

12. A system according to claim 1 adapted for uterine aspiration and wherein said system has a vacuum less than 0.2 atmosphere at the commencement of a procedure.

13. A system according to claim 12 wherein said bottle has a vacuum less than 0.1 atmosphere at the commencement of a procedure.

14. A system according to claim 1 including a vacuum level indicator for use in said collection bottle comprising an elastic non-porous membrane charged with a predetermined quantity of gas at a pressure higher than said vacuum, said membrane being positioned inside said collection bottle.

15. A system according to claim 14 wherein said nonporous elastic membrane defines an enclosed volume inside said bottle, said predetermined quantity of gas within said enclosed volume being sufficient to provide a first visually observable expansion of said elastic membrane when said bottle is empty and evacuated, and a different expansion when said bottle is either substantially filled with aspirated material or when said bottle is no longer evacuated.

16. A system according to claim 14 wherein said elastic nonporous membrane detines a portion of the space inside said bottle, and being charged with said predetermined quantity of gas, said membrane expending due to the presence of said gas when said bottle is evacuated and contracting to a readily observable different volume when said bottle is filled to more than 70 percent of its capacity by aspirated uterine liquids and semisolids.

17. A system according to claim 12, wherein said bottle has a volume capacity between 100 and 500 milliliters.