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Patent 1038251 Summary

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(12) Patent: (11) CA 1038251
(21) Application Number: 171924
(54) English Title: MEDICAL ASPIRATION SYSTEM, AND METHOD
(54) French Title: APPAREIL MEDICAL D'ASPIRATION ET MODE D'EMPLOI
Status: Expired
Bibliographic Data
Abstracts

English 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.


Claims

Note: Claims are shown in the official language in which they were submitted.


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

21

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.

23

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.




24

Description

Note: Descriptions are shown in the official language in which they were submitted.



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.
-- 3 --



. . . ~


~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
- 4 -



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,
- 5 -

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
- 6 -

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.
. q

- .
. :


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
-- 11 --

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.
- 12 -


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
- 13 -
:


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)




- 15 -

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
- 16 -
;

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
- 17 -


'.
. -

-: ';




:: -
'-:

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


- 19 -



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.



- 20 -

Representative Drawing

Sorry, the representative drawing for patent document number 1038251 was not found.

Administrative Status

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Administrative Status

Title Date
Forecasted Issue Date 1978-09-12
(45) Issued 1978-09-12
Expired 1995-09-12

Abandonment History

There is no abandonment history.

Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
BRIDGMAN, HENRY
Past Owners on Record
None
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Description 1994-05-19 19 713
Drawings 1994-05-19 1 42
Claims 1994-05-19 4 141
Abstract 1994-05-19 1 16
Cover Page 1994-05-19 1 14