Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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"Apparatus for determining the pressure between a support
dressing and a body portion surrounded by said support
dressing".
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for de-
termining the pressure between a support dressing and a body
portion surrounded by said support dressing.
With certain kinds of hurts, such as fractures, strains
or the like, the body portion concerned is surrounded by a
support dressing in order to provide a splinting, to maintain
motionless this body portion and to ensure a recovery of the
fracture in the correct position of the fragments at the point
of the fracture. Generally, a plaster of Paris dressing or
another rigid dressing producing a suitable splinting of the
body portion concerned is used as a support dressing. It is
a disadvantage of this procedure that normally this body portion
swells up within the first time after application of the support
dressing, whereby the swellin~ can assume such an amount that
the related limb is tied off so strongly by the inflexible
support dressing that an irreversible derangement and in
extreme cases even a mortification of said limb ma~ be provoked.
In order to avoid this drawback it i9 known to split the
support dressing in the first instance and to bend it up when
the swelling occurs so that the swollen limb has room within
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the support dressing, and only to apply a closed plaster of
Pari~ dressing after termination of the swelling. By such a
plaster of Paris dressing being split the disadvantage is
produce~ that the body portion concerned is insufficiently
su~ported, in particular when the swelling does not occur
early
to the extent expected or when it fades/away. Then, the frag-
ments can displace themselves at the point of fracture and
the desired curing o~ the fracture is no more ensured.
SUM~ARY 0~ ~HE I~VE~TION
It is an object of the invention to provide an apparatus
by which a continuous surveillance of the course of the pressure
is made possible either by the patient himself or by a super-
visor. ~hereb~ especially an increase of the pressure should
be recognized so early that there remains enough time to visit
a doctor or a hospital.
It is a further object of the invention to provide a
small sized apparatus to be accommodated in the support dressing.
The apparatus according to the invention shall make it possible
not only to deter~ine an inadmissible increase of presqure, but
also a decrease of the pressure below a predetermined value,
since in this case a sufficient support of the body portion is
no longer accomplished. Moreover, the apparatus according to
the invention shall enable an adjustment so that starting from
a basic value positioned by the adjustment, an increase or a
decrease of the pressure as well as the relative amount of
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these values in relation to the adjusted basic value may be
determined in a simple manner.
Finaly, it is an object of the present invention to build
up the apparatus in such a manner that the essential components
of the apparatus could be removed when a surveillance of the
pressure is no longer necessary, and could be applied to
another patient without damaging thereby the support dressing.
~R~EF D~SCRIP~ION OF THE DRAWI~GS
~ he invention is schematically illustrated in the accom-
panying drawings by me~ns of some embodiments.
Fig. 1 shows a longitudinal section of a retaining body
of an apparatus according to the invention anchored
in a support dressing;
Fig. 2 represents an ambodiment of an apparatus acco~din~
to the invention anchored in a support dressing;
Fig. 3 is a plan view onto Fig. 2 wherein the support
dressing is omitted;
Fig. 4 shows a longitudinal section of a further embodi-
ment of an apparatus according to the invention
2Q anchored in a support dressing;
Fig. 5 is a topview onto ~ig. 4; and the
~igs.6 and 7 show further variants of the apparatus
according to the invention in respective longitudinal
sections.
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DESCRIPTION 0~ ~HE PRE~'ERRED E~BODI~iENTS
In a support dressing 1, for instance being a plaster of
Paris dressing or another rigid dressing, a retaining body 2
is anchored that is formed by a socket. The socket is provided
with a thread 3 and has projections on its periphery. ~hese
projections may be formed by flute-defining peaks 4. Instead
of these flute-defining peaks 4 or additionally to the same
flukes 5, for instance of plastic material, may be mounted at
the lower end of the retaining body, thus likewise forming
projections. ~he flute-defining peaks 4 as well as the flukes 5
ensure a secure and immovable anchoring of the retaining body 2
within the support dressing 1 when the same has been solidified.
The ~lukes 5 bearing the retaining body ? prop against the body
portion during the application of the support dressing so that
the retaining body 2 takes the desired position.
Into the internal thread 3 of the retaining body 2 either
the external thread of a filling body or the external thread
of a housing 10 may be screwed, the latter containing means for
sensing the pressure, means for indicating the pressure sensed
and an arrangement through which the pressure sensed is trans-
feredOto said means for indicating thi~ pressure. This design
makes it pos~ible, first only to anchor the retaining body 2 in
the support dressing. ~he opening within the retaining body 2,
wherein then the housing 10 is screwed~ is suitably closed by
the filling body during this procedure. In this way the
penetrating of liquid plaster or the like into the interior of
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the retaining body 2 is preYented. When the support dressing
has been solidified, the filling body is screwed out and the
housing lO is inserted. By screwing the housing more or less
deep into the retaining body 2 ~n adjustment of the apparatus
for indicating the pressure sensed may be effected. ~urthermore,
this arrangement has the advantage that the housing lO may be
screwed out of the retaining body 2 after the swelling has
been faded away, and may be applied anew for another patient
without damaging the support dressing l when removing the
housing lO. Then, on]y the retaining body 2 remains in the
support dressing l whereby the opening may be closed again by
the filling body.
~ he internal thread 3 of the retaining body 2 and the
external thread of the housing lO cooperating with it suitably
are formed as a fine thread, thus facilitating the adjustment.
The filling body should extend up to the lower end of the
retaining body 2 so that the thread 3 is protected over its
whole length and that after removal of the housing lO an oedema
may not be caused by ~he cavity thus formed.
The adjusted position of the housing lO within the retaining
body 2 is secured in the manner decribed below in detail so that
an undesired misadjustment of the housing lO i9 not possible.
~he means for sensing the pressure of the apparatus according
to the invention a~ shown in ~igs. 2 and 3 have an insert
element 13 slidably arranged within the housing lO which is
secured against dropping out by a yarn 14 or the like and
which is reset into its inoperative position by a spring 15.
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The insert element 13 is connected to an indicating device 17
through a lever system 16, said indicating device 17 being
passed through a slot 18 in the front wall of the housing 10
and being bent to fo~m an indicator 19 at its end protruding
~rom the slot 18. This indicator 19 cooperates with a graduation 20
applied to the outer surface of the front wall of the housing 10.
This graduation 20 is divided into three ranges 21, 22 and 23.
In this connection the arrangement may be such that for instance
then, when the indicator 19 is within the range 21, there is
a too low pressure between the support dressing and the body
portion, when the indicator 19 is positioned within the range 22
it indicates the pressure desired, and when the indicator 19
reaches the range 23, there is a pressure making necessary a
medical intervention. ~he arrangement, however, may also be
such that the range 21 corresponds to the normal pressure and
the range 22 limits a pressure o~ tolerable values, whereas
the range 23 defines the critical range wherein the doctor has
to take precautionary measures. In each case the housing has
to be screwed so deeply into the retaining body 2 that with
20 normal pressures the indicator is about the center of that
range defining the normal pressure.
Afterwards, the position of the housing 10 is secured in
accordance with the Figs. 2 and 3 by a lock nut 25 so that the
housing 10 can no longer be twisted.
~he indicator 19 and the graduation 20 are covered by a
glass 24 formed as a magnifying lens so that the pressure
Yalues represented are clearly distinguishable although the
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dimensions of the apparatus are small.
In the embodiment according to the Figs. 4 and 5 the means
for sensing the pressure comprise a hollow body 26 located
within the housing 10, having flexible walls and protruding
from the lower side of the housing, thus abutting against the
body portion. The hollow body 26 is filled with an incompressible
fluid and is connected through a conduit with a sight glass 28
wherein the end of the head of liquid is visible. The sight
glass 28 likewise cooperates with a graduation 20 equally
having the three above-mentioned ranges 21 to 23. ~y the
pressure occurring with a swelling of the body portion and
acting in the direction of the arrows onto the hollow body 26
having flexible walls, the head of liquid within the sight glass 28
is displaced, whereby the change of pressure is visible on
the graduation 20.
Also with the apparatus shown in Figs. 4 and 5 an adjust-
ment may be effected in that the housing 10 is screwed into
the retaining body 2 so deeply that the end of the head of
liquid is just at the center of that range of the graduation 20
which is limited by those values between which the pressure may
vary without affecting the patient. The adjusted pasition of
the housing 10 is secured in the embodiment according to
Figs. 4 and 5 by a fixing scr~w 29 screwed in the housing 10
at the front wall and cooperating with the front wall of the
reta~ning body 2, rather than by a lock nut.
In the embodiment ac^ording to Figs. 2 and 3, it may occur
that then, when the pressure does not act in sliding direction
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of the insert element 13, the same may become jammed, thus
indicating incorrect pressure values. In order to avoid this,
the insert element 13 in conformity with ~ig. 6 i~ biased via
a hollow body 30 having flexible walls. An incompressible fluid
is in the hollow body, as before. That area of the wall of the
hollow body which abuts against the body ~ortion is curved.
~his embodiment ensures that pressures acting onto the hollow
body 30 from different directions are transfered in sliding
direction onto the insert element 13, thus preventing a
ja~ming of the latter.
In a hollow body 31 of the embodiment according to ~ig. 7
which abuts with a flexible wall against the body portion, as
before, a piston 32 is provided being biased Qn one side by a
fluid within the hollow body 31 and on the other side by a
spring 33. A piston rod 34 passing through an opening of the
hollow body 31 i9 connected with an indicating device 17
passed through the slot 18 in the front wall of the housing
and being bent to form an indicator 19 at its end projecting
from this slot, just as in the embodiment of ~igs. 2 and 3.
The indicator 19 again cooperates with a graduation 20 covered
by a glass 24 formed as a magnifying lens,
The position of the housing 10 in relation to the retaining
body 2 in this embodiment is ensured again by a lock nut 25,
but, of course, instead of the lock nut 25 also a fixing screw 29
may be provided.
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