Note: Descriptions are shown in the official language in which they were submitted.
2~1 30~
WO ~3/01749 PCr/AU92/00367
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Title: PAP SMEAR SAMPLING DEVICE~ .
TECHNICAL FIELD ~:
The present invention relates to pap smear sampling
devices of the type used in the gynaecological field for
the detection of cancer cells in the female cervi~.
BACKGROUND ART
A number of sampling devices have hitherto been ~-
available to conduct these so-called "pap smear" tests.
Such devices are generally adapted to be inserted into ~:
the cervix and then rotated so as to wipe or scrape the ;
surface of the cervix, in an attempt to collect and
retain sample cells. Oncs the sample has been taken, at
least a proportion of the cells collected on the sampler
are-tr~ans~erred to a ~lass optical slide for subsequent
examination under a suitable microscope, in an attempt
to ascertain ths cancer status of the cervix. This
procedure is well known and understood by those skilled
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in the art, and so will not be described in more detail
her
It has been found in practice, however, that known
pap smear samplin~ devices are inadequate in a number of
significant respects. It has been shown statistically
that the accuracy of cervical cancer detection is
relatively low, and many cases go undetected in the
early stages, largely as a result of the inefficiency of
the pap smear sampling devices curr~ntly in use.
One known type of sampling de~ice is formed from
wood and incorporates a sampling head corresponding
generally to the cross sectional surface profile of the
cervi~. However, such ~spatula~ type devices are
e~cessively rigid, and so are not well ada~ted to
properly accommodate the wide variations in size and
shape of cervi~ which are routinely encountered.
Moreover, because of the inability of these rigid
spatulas to conform flexibility to the relatively
comple~ and Yaried surface contours of the cervi~, the
e~fective area of coverage during the sampling procedure
is relatively small. This in turn can lead to
inaccurate diagnosis, and can also cause e~cessive pain
and discomfort to the patient. The spatula type
samplers also have a tendency to cause contact bleeding,
which makes detection of cancer cells amongst the
.interspersed red blood cells considerably more difficult
and less accurate.
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In an attempt to ameliorate these problems, a
number of prior art devices have incorporated various
configurations of bristles, fibres, filaments or
brushes, which are generally mounted on a support arm or
wire. However, these ~br~sh" type devices can also
cause substantial pain and bleeding, as well as damage
to the cervical sample, particularly if suffi~ient care
is not taken during the sampling procedure. Such
. samplers do tend to:give better surface coverage than
the rigid spatula type devices discussed above, by
virtue of the fact that the bristles can resiliently
deform to a certain e~tent, thereby enabling the brush --
to conform more closely to the surface contours of the ~:
cervi~. However, these devices still cannot provide
complete coverage, and in addition suffer the inherent
problem of poor transfer- ability of the collected
sample to the microscope slide for subsequent analysis.
This is largely because the sample cells tend to remain
trapped in the intersticial voids between the bristles
within the inner confines of the brush, and are
therefore not readily accessible and transferable to the
ælides. A~ain, this leads to inaccurate diagnosis,
particularly in the critical preliminary stages of
cervical cancer.
Moreover, with both the major types o known
samplers discussed above, the cancer cells and
dysplastic cells are often damaged or de~ormed during
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WO93/01749 ; PCT/AU92/0036
the sampling procedure, and so become more difficult to
detect accurately with known diagnostic techniques.
Combined with the inherent inadequacies of the sampling
devices in terms o~ poor coverage and inadequate sample
transfer, this reduces even ~urther the accuracy of the
pap smear test in terms of its ability to provide a
reliable indication of cervical cancer.
Finally, many known sampling-devi~es tend not to be
able to diff~rentiate::ef ectively`between the inside and
outside sample areas of the cervi~; and so are not
effective in isolating sample cells collected from the
endocervi~ and ectocervi~ respectively, which is also
important for accurate diagnosis.
It is therefore an object of the present invention
to provide an improved pap smear sampling device which
overcomes or substantially ameliorates at least some of
the disadvantages of the prior art.
DISC~OSURE OF THE INVENTION
Accordingly, the invention provides a pap smear
sampling device for use in the detectiQn of cancer cells
in the female cervi~, said device including a sampling
head adapted to engage and scrape the surface of the
cerYi~ for collection of sample cells, and an elongate
handle~to permit remote rotation and manipulation of the
sampling head, said sampling head comprising a probiny
stem e~tending generally axially from the handle for
insertion into the cervi~ to collect sample cells from
WO ~/0174~ 3 ~ g ~ PCT/AV92/00367
the endocervix, a relatively rigid support portion
e~tending outwardly from the handle or the stem, and a
relatively flexible web portion e~tending generally
intermediate the stem and the support portion to define
a fle~ible wiping blade adapted to scrape and collect
sample cells from the ectocervi~, said ~lade being :
adapted fle~ibly to conform closely to the surface
contours of the ectocervi~,-~hilst maintaining an
.effective scraping angle upon said rotation and: ~-
manipulation of-the sampling head.~
Preferably, the probing stem includes at least one
longitudinally extending rib adapted rotatingly to
scrape sample cells from the endocervix, and at least
one corresponding longitudinally extending recessed
channel or groove disposed adjacent the rib to retain
the sample cells scraped from the endocervix by the
rib. In another embodiment, the stem takes the form of
a relatively flat narrow blade generally rectangular in
transverse cross section, in which case the sample is
simply retained on the flat faces of the stem.
Pre$erably also, the device includes a relatively
fle~ible joint disposed intermediate the handle and the
sampling head to permit a degree of relative a~ial
movem~nt therebetween.. This enables effectiv~ rotation
and manipulation of the device with the handle inclined
at an oblique angle with respect to the head~ In the
preferred embodiment, the fle~ible joint is conveniently
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provided by an intermediate neck region of reduced cross
sectional area immediately adjacent the sampling head.
Preferably also, the sampling head is formed
substantially from a suitable elastomeric material such
as rubber, santoprene, silicon, flexible polyurethane,
or the like.
In one embodiment, the sampling head includes a
.second support arm effectively interconnected with the
first, and e~tending asially within the probing stem to
facilitate insertion into and-loca~ion within the
cervix. The first and second support arms are
preferably formed from spring steel wire or plastic, and
are connected to the handle for releasable detachment
from a separate elastomeric portion of the sampling head
incorporating the fle~ible web. In other embodiments,
the support arms may be integrally moulded within a
surrounding elastomeric portion, to form a composite
sampling head of unitary construction.
In the preferred embodiment, however, the sampler
is fsrmed from one type of material in a single moulding
and the difference in flexibility between the wiping
blade and the support portion is achieved by an
appropriate variation in material thickness.
BRIEF DÉSCRIPTIO~ OF DRAWINGS
Preferred embodiments of the invention will now be
described, by way of ezample only, with reference to the
accompany drawings in which:
WO93/01749 21 1 3 0 8 ~ PCT/AU92/00367
Figure l is a side elevation showing a first ~:
embodiment of a pap smear sampling device according to
the invention;
Figure 2 is a cross-sectional view taken along line ~.
- 2~2 of Figure l;
Figure 3 is a diagrammatic side elevation showing
the device of Figure l in position ready for use
adjacent a cervis; . - ~
. ~^.- ~Figure 4 is-~a side elevation similar:,to~sFigure l
showing the sampling head of a second embodiment of the
invention;
Figure 5 shows a third embodiment of the invention;
Fîgure 6 shows a fourth embodiment;
Figure 7 is a front elevation showing a furthsr
embodiment of the invention, formed from a single
material;
Figure 8 is a side elevation of the sampler of
Figure 7 showing the variation in thickness between the
wipin~ blade and the support arm; and
Figure 9 shows an alternative form of flesible neck
disposed intermediate the sampling haad and th~ handle.
BEST M~DE FOR CARRYING OUT THE INVENTION
Referring firstly to Figures l to 3, the invention
provldes a pap smear s.ampling device l for use in the
detection of cancer cells in the female cer~ig 2 in
accordance with the established gynaecological "pap
smear~ testing procedure well known and understood by
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WO93/01749 ' PCT/AU92/0036;~.
those skilled in the art. The sampling device includes
a sampling head 5 adapted to engage and scrape the
surface of the cervix for collection of sample cells,
and an elongate handle 6 to permit remote rotation and
- manipulation of the sampling head when engaged with the
cervi~. -
The sampling head 5 comprises a relatively firmprobing stem 10 e~tending generally a~ially from the
~ handle 6 for insertion into':the`'cervix'to'`collect sample
- - cells from the endocervi~ l2. The-sampling head further
,încludes a irst outwardly e~tending relatively rigid
support arm 13 formed from sprin~ steel wire, plastics
or other suitab~e makerial. A relatively soft fle~ible
web 14 e~tends intermediate the stem 10 and the remote
end of the first support arm 13 to define a ~lexible
wiping blade 15 adapted to scrape and collect sample
c811s from the ectocervix 16. The flexibility of the
web 14 ena~les the marginal edge of the wiping blade 15
1esibly to conform closely to the complex surface
contours of the ectocervix, whilst the relatively rigid
support provided by first arm 13 enables an effective
æcraping angle relative,to the cervix to ~e maintained,
upon rotation and manipulation of the device. The
sampllng head preferably includes a second support arm
17 interconnected with the first arm 13 to provide
relatively rigid internal support for the stem, thereby
facilitating insertion into and positive location within
WO93/01749 211 3 0 8 ~ PCT/AV92/00367
the cervi~.
The stem 10 includes a longitudinally e~tending
protruding rib 20 adapted to scrape the endocervix upon
rotation of the sampling head, and a pair of
corresponding longitudinally extending recessed channels
21 disposed on either side of the rib to retain the
sample cells scraped from the endocervi~ by the rib,
upon~withdrawal of the sampling device.~;~
The handle 6 immediately adjacen~f-the~sampling head
includes a neck re~ion of reduced cross-sectional area
forming a fle~ible Uuniversal~ joint 25. The joint 25
permits a Iimited degree of relative movement and a~ial
misalignment ~etween the handle and the sampling head.
This facility enables effective rotation and
manipulation of the sampling head with the handle
inclined at an angle with respect thereto. Other forms
of fle~ible joint are also envisaged.
In the embodiment of Figures 1 to 3, the relatively
soft and 1esible portion of the sampling head including
the probing stem and transverse web is preferably
moulded from a suitable elastomeric material such as
rubber, santoprene, si1icone, flesible polyurethane,
polypropylene, polyethylene or the like. The support
arms~l~ and 17 are preferable formed from spring steel
wire, although it will be appreciated that any suitably
- firm or relatively rigid metal, plastics, polymer, wood
or other material can also be used.
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A second embodiment of the invention is shown in
Figure 4, wherein corresponding features are denoted by
corresponding reference numerals. In this embodimen~,
the central and lower portion o the web 14 is removed,
effectively to define cut-out region 27. This
configuration provides greater flexibility for the
wiping blade 15, and thereby reduces the a~ial force
required or the blade to conform closely-lto the comple~
outer surface contours-of the ectocervi~ during the
sampling procedure. This configuration also saves on
material costs. It should be appreciated, however, that
in this embodiment, the transverse web 14 is still
provided with sufficient frontal area to retain the
collected cell sample, below the operative marginal edge
of the wiping blade. A similar form of the invention is
shown in Figure 6.
In the embodiments of Figures 1, 4 and 6, the
elastomeric portion 28 of the sampling head is formed in
a separate moulding step, and is releasably detachable
from the complementary support arms 13 and 17 which are
fi~edly connected with the handle. In this way, the
design provides for the substitution of interchangeable
elastomeric head portions 28 of different size, shape,
or res~liency, to suit par~icular applications. Thus, a
range of interchangeable elastomeric head portions can
be provided to enable the sampling device to be tailored
to suit individual patients' requirements.
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WO93/01749 PCT/AU92/00367
A third embodiment of the invention is shown in
Figure 5, where again, corresponding features are
denoted by corresponding reference numerals. In this
embodiment, the elastomeric material is actually moulded
around an internal wire support frame, consisting
essentially of the first and second support arms 13 and
17. The composite sampling head is then attached as a
unitary structure to a complementary handle by means of
-~ elastomeric boss portion 30, which is captivsly retained
within a complementary socket formed in the handle (not
shown3.
Figures 7 and 8 show a fourth embodiment of the
invention. In this case, there is no separate suppsrt
frame formed from spring steel wire or other material.
Rather, the entire sampler is formed from a single
suitably flexible material such as polyethylene, or
polypropylene as a one piece moulding. There is,
however, still a difference in relative flexibility
between the wiping blade 15 and associated support arm
13 which, as best seen in Figure 8, îs achieved by a
difference in material thickness rather than material
type. More particularly, the web portion 14 defining
the scraping blade is relatiYely thin and
correspondingly flexible, thereby ena~ling it to
resiliently deform to accommodate irregularities in the
surface profile of the ectocervix during sampling. ~n
the other hand, the support portion 13 is relatively
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thick in transverse cross section particularly adjacent
its base, thereby to provide a relatively rigid support
for the remote end of the wîping blade.
In this embodiment, cut-out region 27 is provided
- to enhance flexibility of the wipin~ blade and economise
on material. It should be appreciated, however, that
this portion could be Yfilled-in~ so as to form a gusset
extending between the remote end of the wipinq blade and
.~ . the ba~e of..the sampling head. This would function in a
mecha~ically analogous way. However, instead of a
discrete support arm separate from the web, there is
simply a smooth transition from the relatively thick
support section of the gusset adjacent the base of the
sampling head, to the relatively thin and flesible
operative edge of the scrapin~ ~lade. Further, the
endocervical probe portion does not incorporate discrete
ribs and channels, but rather has a simple recta~gular
cross-sectional configuration, which has also been found
to be effective in collectin~ cells from the endocervix.
This embodiment also incorporates an additional
sampl ing ~ember 35 disposed on the terminal end of the
handle re~ote from the head, for use in applications not
requiring penetration of the probing stem.
-In each case, the operative edge of the wiping
blade is adapted to curvs through an angle of between
around 90 to 180-and preferably around 140 from the
stem. That is to say, a tangent projected from the
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WO93J0174~ PCT/AU92/00367
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r~mote tip of the operative edge of the wiping blade
intersects a projected a~is of the stem and handle at an
included angle of between around 0 to 90, and
prefera~ly around 40~. This e~tent of curvature ensures
adequate coverage of the ectocervi~, and is only able to
be effectively achieved by virtue of the support
afforded to the remote end of the wiping blade by the
~upport portion.
Turning now to:describ~:briefly the method of use,
the sampling device is first positioned in the
conventional manner and the probing stem lO inserted
into the cervis, thereby radially locating the sampling
hsad. The device is then manually rotated by the handle
(in either the clockwise or anticlockwise direction~.
I~ this way, the endocervix is scraped by longitudinal
rib 20 whereby sample cells are collected and retained
within the recessed channels 21. In the case of the
embodiment of Figures 7 and 8, the endocervical cells
are simply retained on the flat faces of the probe.
Simultaneously, the wiping blade lS defined b~ fle~ible
web portion l~ scrapes the entire outer surface of the
ectocervis, whsreby sample cells are collected and
retainsd on the frontal surface of the web. During this
opera~on, as a result.of asial pressure applied by the
operator, the wiping blade flexibly and progressively
conforms to the complex profiles of the cervi~,
including any surface irregularities. At the same time,-
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WO93/01749 PCT/AU~2/~036
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the support arm or section 13 maintains an effective
scraping angle over the entire cervix by providing
support for the end of the wiping blade remote from the
stem and thereby permitting substantially uniform
pressure distribution across the blade. In this way,
sample cells are recovered from substantially the entire
outer surface of the cervix. It will be appreciated
that the relative flesibility of the web intermediate
the~support portion and stem ma~imises the effective
sampling-~area, whilst minimising contact bleeding and
patient discomfort. This is in contrast with prior art
devices, which have generally been unable to eff2ctively
wipe the entire ectocervi~, because of the lack of
fle~ible form-fitting capability and/or the lack of
support for the remot~ end of the wiping which prevents
sufficient pressure to be applied uniformly across its
operative edge.
Once the sampling procedure has been completed, the
device is withdrawn. The samples from the stem 10 and
web 14, containing cells collected from the endo~erYi~
and ectocervix respectively, are then transferred by a
simple wiping action onto an appropriate optical slide
for subsequent analysis and testing in accordance with
estabr~shed diagnostic procedures.
During transfer of the sample from the stem to the
slide, in the embodiments shown in Figures 1 to 6,
sufficient wiping pressure is applied against the slide
WO93/01749 21~ 3 0 ~ ~ PCT/AU92/00367
to fold back the rib 20 so that the full sample retained
within-the channels 21 is exposed and progressively
transferred by the wiping action onto the slide.
Similarly, a simple wiping action is sufficient to
transfer the entire sample from the frontal face of the
web 14 to the slide. This operation is also facilitated
by the support afforded to the web by the support
portion 13. Consequently, substantially the entire
sample is available~for-analysis. ~
. In other embodiments (not shown), the web l4 may
include a series of spaced apart slits estending
generally parallel to the stem, whereby the marginal
edge of the wiping blade 15 is still effectively
continuous, but defined by a series of complementary
wiping ~fingers~. It is envisaged that this will
further enhan~e the ability of the wiping blade to
conform closely to irregular surface contours of the
cervi2, whilst still providing excellent coverage over
substantially the entire outer surface of the cervix and
gubstantially ~omplete transferability of the sample to
a slide.
It will be apparent that the present invention
provides a number of significant advantages over the
prior ~art. Firstly, as a result of its inherent
~form-fitting" capability, the effective area of
coverage during the sampling procedure for a given
length of wiping blade is greatly increased,
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particularly when compared with the rigid prior art
"spatula" type devices. Moreover, the support provided
for the remote end of the wiping blade enables it to
wrap further around the ectocervi2 than fle~ible prior
- art samplers, and still support sufficient scraping
pressure to consistently recover a complet~ sample.
Furthermore, the device according to the present
invention enables virtually complete transfer of the
collected sample to a microscope slide for subseguent
analysis. There is no possibility of sample cells
remaining trapped in intersticial voids between bristles
fibres, or filaments as occurs with prior art ~brush"
type devices. As previously mentioned, on a ststistical
basis this significantly reduces the probability of ~:`
inaccurate diagnosis. Additionally, the fle~ible joint
provided intermediate the sampling head and the handle
enables the device to accommodate a significant degree
of operator error, by virtue of the fact that the
sampling head is adapted automatically to assume the
optimum position around the cervi~, despite relative
a~ial misalignment of the handle within a reasonably
broad range of tolerance.
The improved configuration and fle~ibility of the
sampl-lng head thus enables the device to accommodate a
wide variation in cervix size and shape, whilst
affording precise control and minimising pain,
discomfort, blesding, and cell.damage. By reducing
WO93/01749 21 1 3 ~ ~ ~ PCT/AU92/00367
contact bleeding and cell damage, the likelihood of
inaccurate diagnosis of the cancer status of the cervix
is siqnificantly reduced. Sampling time is also
significantly reduced because the device is able to
provide an effective and accurate "first time" sample.
The accuracy and specificity of the diagnosis is
further enhanced by enabling distinct inside and outside
cervi~ samples to be taken simultaneously, and
subsequently isolated on separate slide~ for individual
analysis if required. More particularly, because the
sample is transferable by a straight wiping action, the
relative transverse position of any cancer cells
detected on the slide can be appro~imately correlated to
a correspondi~g position on the surface of the cervi~, ~
thereby providing a relatively accurate target zone for ~.
subsequent testing. This is in contrast with prior art
sampling devices, which require the sample to be
transferred to a slide by a random brushing, scraping or
spreading action which effectively destroys any
~eaningful correlation between the relative positions of
sample cells on the slide. Thus, it will be apparent
that the present invention represents a commercially
significant improvement over the prior art.
Although the invention has been described ~ith
reference to specific e~amples, it will be appreciated
by those skilled in the art that the invention may be
embodied in many other forms., For e~ample, the probe
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need not incorporate a lonyitudinally extending rib and
channel as described, but may incorporate a series of
longitudinal ridges, recessed grooves, surface dimples,
or be of any other suitabls non-circular cross-sectional
- profile.
.~ .
