Note: Descriptions are shown in the official language in which they were submitted.
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Venous Tourniquet
[0001] The invention relates to a venous tourniquet, having a constricting
strap that can be placed
around a body part and that itself is embodied elastically in the
circumferential direction or is provided
with at least one elastic portion, and having a closure device by means of
which the constricting strap
can be locked in its state in which it is wrapped tightly around a body part,
to form a tightening loop.
100021 One such venous tourniquet is disclosed in US Patent 3,930,506. An
adhesive portion is applied
to an end portion of the constricting strap, for fixation of a tensing loop
wrapped around the body part
with tensile stress. If this portion is not fixed in the correct position in
the first fixation, then reliably
fixing it again is not ensured, which can have disadvantages in terms of use.
Applying the adhesive also
entails corresponding effort.
100031 In US Patent 3,628,536, a thither venous tourniquet is disclosed. It
has a closure device with
openings, distributed over the length, and with a protrusion attached to one
end, which protrusion is
adapted to engage the openings.
[0004] In published US Patent Application 2012/0071917 Al, a constricting
strap device for body parts
for preventing severe blood loss in injuries is disclosed. In this known
constricting strap device, a
tightening device for attaining high tension of the constricting strap,
wrapped into a loop around the
body part, and a tension indicator are provided, with which tension indicator
a tension of the
constricting strap that is generated can be ascertained either in tactile
fashion or visually. For example,
to that end, as shown in Figs. 14A and 1411 and the specification of this
document, a tension cloth is
folded and fixed in the folded area at fastening locations, which tear if the
tension is excessive. The
fastening locations can have variously many fastening points over the width of
the tension cloth, as a
result of which the fastening locations tear if the tensile stress differs
accordingly. In any case, a tensile
stress this high must not be applied until in order to cause tearing at the
fastening location or locations,
after which, however, the tensile stress abruptly drops. With these
provisions, a metered tension, of the
kind that is effective in venous tourniquets, for instance, in order to
occlude a venous blood flow, is
difficult to achieve and detect. Also, the closure device is relatively
complicated.
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[0005] Further constricting strap devices for body parts are shown in US
Patent 5,653,728 A, WO
2006/015987 Al, GB 2 424 189 A, US Patent 6,525,238 B2, US Published
Application 2008/0312682
Al. and US Patent 6,250,047 131. The constricting strap devices are provided
with various closure
devices, and the locking or fixation is sometimes inconvenient, or the
construction is complicated. For
instance in US 5,653,728 A and WO 2006/015987 Al, versions of constricting
strap devices are also
disclosed that can be thrown away after use, of the kind often needed in
clinical use for compliance
with hygiene regulations.
100061 DE 10 2009 025 416 134 discloses a supporting or fixation belt with at
least one flexible,
inelastic portion and fixation devices for fastening belt regions to one
another or to orthopedic devices.
The fixation devices can be embodied as hook-and-loop closure elements and
stitched on, glued, or
welded on, or sewn onto ends of a belt strap. The top side of a continuous
elastic belt portion can also
be equipped with a plush layer, while on the underside, fixation devices for
fixing the end regions to
one another or to the orthopedic devices are provided. This kind of support or
fixation belt with fixation
devices in its end regions is not adjustable to variable loop sizes and cannot
be used as a venous
tourniquet.
100071 Further bandlike belts or belt portions with hook-and-loop closure are
shown in EP 2 045 047
A2, GB 479 442 A, and GB 1 033 130A.
100081 The object of the invention is to furnish a venous tourniquet of the
type described at the outset,
which is simple in construction, functions securely, and is easier to use.
[0009] This object is attained with the features of claim 1. It is provided
here that the closure device is
embodied as a hook-and-loop closure with two closure parts engaging one
another in locking fashion.
The construction provides simple manipulation with only a few gestures in
fastening it to the body part,
in particular an arm, with sufficient tensile stress, for instance for
occluding a vein. Advantageously, the
constricting strap device can be used as a disposable item in order to meet
hygienic requirements. The
two closure parts, preferably with hook elements on one side and loops on the
other side, lead to a
stable connection with tensile strength in the superficial or circumferential
direction of the body part.
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[0010] An especially advantageous construction for production and simple use
is obtained in that a first
closure part is formed of the band material of the constricting strap itself,
and a second closure part is
formed of a portion of material secured to the band material, or the first and
the second closure parts
are integrated with the band material.
[00111 An advantageous embodiment in terms of function and use is that that
the constricting strap is
made from plushlike, tear-resistant material with high tensile strength.
10012] A further advantageous embodiment is obtained in that the constricting
strap is made from a
nonwoven, such as spunbond fabric, felt, or paperlike material with a
roughened surface or a surface
havine, fine hairs. The felt can be produced for instance using water-jet
hardening.
10013] Various other advantageous embodiments are obtained in that the
constricting strap is made
from polyester, polypropylene and/or viscose material.
100141 For the function and use it is also advantageous that the constricting
strap and the second
closure part have the same width, in the range from 1 cm to 4 cm, preferably
between 1.5 cm and 3 cm.
[00151 Further advantages for use are obtained in that at least one tension
indicator for determining a
state of tension of the constricting strap is present, which is embodied in
such a way that a defined state
of tension is apparent to a user.
[0016] With these provisions, the user, for instance in an embodiment of the
constricting strap device as
a venous tourniquet, can adjust the relatively slight tensile stress required
to suppress blood flow (for
example, ca. 10 mm fig in the vicinity of capillaries or < 25 mm Hg in the
vicinity of larger veins)
exactly. As a result, the person being treated is also not stressed any more
than necessary.
[0017] In an advantageous embodiment for detecting the tensile stress
generated is that the tension
indicator is embodied as an elastic portion on the constricting strap in the
stretching direction between
two fixation points, having a strap portion embodied of a flexible, inelastic
material and spanning a
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defined excess length relative to the unstressed constrictine, strap. It' the
strap portion embodied with an
excess length with respect to the spacing of the fixation points in the
untensed state of the constricting
strap (for example, as a l'olded portion) is still loose, then a defined,
predetermined tension state is not
yet reached. Conversely, if the flexible inelastic strap portion extends all
the way along the constricting
strap, because the elastic portion is has stretched between the fixation
points, then the defined tension
state, for instance for suppressing the venous blood flow, is attained. By
means of the excess length of
the strap portion between the two fixation points, a desired defined tension
state for a given application
can thus be specified by the manufacturer, which tension state is easily and
unambiguously detectable
and adjustable in use by the user.
[0018] An advantageous variant embodiment comprises that the constricting
strap is embodied of a
flexible inelastic material, and the strap portion forms an integral part of
the constricting strap, and an
elastic clement forming the elastic portion is attached at the fixation
points.
00191 Another advantageous variant embodiment comprises that the constricting
strap itself is
embodied at least in some portions as an elastic portion, and the strap
portion of inelastic material is
attached to the elastic portion at the fixation points.
[0020IA constricting strap device that is advantageous as a disposable item
comprises that the elastic
portion or a different portion of the elastic strap is provided with a usage
indicator, for instance of paper
or lacquer, that tears or is damaged when stretching first occurs. The tearing
force of the usage
indicator is advantageously low, so that it affects the tension method of the
constricting strap as little as
possible, and the tear ensues for example already at low elongation of a few
percent of the elongation at
the defined tension state (for example, no more than 10% or 20% of the
elongation in the defined
tension state). This can be attained for instance by means of a suitable
material selection and/or
material thickness and/or shape of the usage indicator or by tearing off at an
attachment point.
100211 The provisions by which the attachment is brought about by securing the
second closure part
and optionally the elastic portion or the strap portion to the constricting
strap at the fixation points by
means of gluing, welding, thermoplastic methods, or stitching are advantageous
from the standpoint of
both manufacturing and function.
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1 0022 1 The invention will be described below in further detail in terms of
exemplary embodiments with
reference to the drawings. In the drawings:
Figs. lA and 1B show a first exemplary embodiment for a constricting strap
device in two
different perspective views;
Fig. 2 shows the constricting strap device of Fig. IA in a top view, a side
view, and a view from
below;
Figs. 3A and 313 show a further exemplary embodiment of the constricting strap
device in the
untensed state of the constricting strap and in the tensed state thereof in a
top view, a side view,
a view from the bottom, and a perspective view, as well as enlarged detail
views in both states;
and
Figs. 4A and 413 show a further exemplary embodiment for a constricting strap
device in the
untensed and in the tensed state in a side view and a view from below.
100231 Figs. IA and 113 show a first exemplary embodiment for a constricting
strap device 1,
embodied as a venous tourniquet, having a constricting strap 10 that for at
least partially suppressing
blood flow can be wrapped in the form of a closed tension loop around a body
part and in the tensed
state can be fixed by means of a closure device 30. The closure device 30 is
embodied as a hook-and-
loop closure with two closure parts engaging one another in locking Cashion,
namely a first closure part
300 and a second closure part 301.
10024] In the exemplary embodiment shown, the constricting strap device 1 has
a tension indicator 101,
with which the tensing force of the constricting strap 10, in the vicinity of
the tension loop wrapped
around a body part, can be detected by a user. The tension indicator 101 is
preferably located in the
vicinity of the closure-side band portion, so that in every case it is subject
to the tensing force exerted
by the tensing loop on the body part it is applied to.
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10025] In the exemplary embodiment shown in Figs. lA and 1B, the constricting
strap 10 itself is
embodied as a first closure part 300 of the closure device 30, while the
second closure part 301 is
embodied as a portion of material secured to the constricting strap 10. An
advantageous aspect is that
the constricting strap 10 is made from a plush material that is sufficiently
tear-proof or has sufficiently
strong tensile strength with respect to the incident elongation forces, which
forms loops (slings) for the
hook-and-loop closure, while the second closure part 301 is embodied as a
short portion of flat material
with hook elements adapted to the loops of the first closure part 300.
[0026] The hook elements preferably have tiny hooks directed counter to the
tensile force or tension
force of the band portion wrapped around the applicable body part; however,
they may also be
embodied in the shape of mushroom caps, flakelike elements, or the like; the
loops, or the sling cloth
containing them, are adapted accordingly. In particular, the loops, which need
not necessarily be
embodied as closed loops, and the hook elements can catch on another in a
miniaturized embodiment in
the form of many tiny hairs, producing a kind of gecko effect. Advantageously,
the loops and hook
elements of the two closure parts are embodied as microelements, in such a way
that the constricting
strap feels soft, even when it is in direct contact with the skin on a body
part that is to be constricted.
100271 In studies, it has been found that the hook-and-loop closure embodied
in the aforementioned
way, in the applied state, absorbs sufficiently strong tensile forces (shear
forces) parallel to the surface
or in the circumferential direction of the constricting strap 10 to ensure the
requisite tying ofT, for
instance of veins, and a tension state of the constricting strap 10 for
generating a pressure of up to 10
mm lig, for example, or up to 25 mm in the vicinity of the veins can be
reliably achieved. For
applying and removal, the hook-and-loop closure can be closed and opened
easily and quickly.
[0028] The constricting strap 10 which for example is between 1 and 5 cm wide
(preferably between
1.5 cm and 3 cm) can be cut from very thin (less than 1 mm) of rolled or two-
dimensional material and
is very flexible while having high tear strength. It can itself have for
instance a slight intrinsic elasticity,
so that after being applied to the body part, it generates an elastic tension
force on its own.
Alternatively or in addition, the tension force can be generated by an elastic
element 20, made from a
suitable material; this element is secured to the constricting strap 10 in the
vicinity of the tension
indicator 101, or outside the tension indicator.
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100291 The second closure part 301 advantageously has the same width as the
constricting strap 10 and
preferably a slight length, for instance between 1 cm and 5 cm. Alternatively,
it can also extend over
the entire or nearly the entire length of the constricting strap 10. The
second closure part 301 is in turn
made from thin, flexible material and is secured, for instance by welding
(laser welding, ultrasonic
welding, or the like), gluing, thermoplastic joining methods, stitching or the
like in an end portion of
the constricting strap 10 or over the entire or nearly the entire length of
the constricting strap. For
locking or closing the hook-and-loop closure, the other loop portion placed
around the body part needs
merely to be pressed against the closure part 301, whereupon the closure parts
lock one inside the other.
In a further variant embodiment, the loops (or slings) are integrated with one
another in the same layer
or the nonwoven material or sling cloth.
[0030] Suitable materials for the constricting strap or the hook-and-loop
closure are viscose, polyester,
polypropylene, and advantageously spunbond fabric is used, in a version that
is kind to the skin.
1003 11 Fig. 2 shows a portion of the constricting strap device, embodied as a
venous tourniquet, with
the constricting strap 10, a tension indicator 101 with an elongation portion
100, and a spanning elastic
element as well as a second closure part 301 of the hook-and-loop closure, in
a plan view, a side view.
and a view from below.
[003211n Fig. 3A, the constricting strap device 1, embodied as a venous
tourniquet, is shown in a top
view, a side view, and a view from below in the untensed state. In Fig. 3B,
the constricting strap device
or venous tourniquet is shown in a tensed state of the constricting strap 10,
also with an enlarged detail
B in the vicinity of the tension indicator 101; the constricting strap 10has
stretched by a defined length
in the vicinity of an elongation portion 100, in which an elastic element 20
is located. As soon as this
defined distance, beginning in the untensed state of the constricting strap
10, or a less-tensed state, is
reached, a defined tension state of the constricting strap 10 exists. The
tensing force effected can be
adjusted by means of a suitable choice of material (material properties and/or
geometric properties,
such as length, thickness, width, recesses, or the like) in manufacture in a
defined way. In Figs. 3A and
313, a usage indicator 40, described in further detail hereinafter, is also
shown.
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[0033] In the exemplary embodiment shown, the constricting strap 10 itself can
be made from inelastic,
but flexible material. When the constricting strap device 1 is manufactured in
rolls, it can be kept on
hand and cut to the desired length of the constricting strap 10.
Advantageously, a recyclable material
can be selected, including with natural reinforcement fibers, for instance,
from renewable resources,
can be incorporated, and the parts, such as the closure device, elongation
portion, fastening means, and
the like can be chosen taking good recyclability into account. The production,
mode of operation and
design of the constricting strap device 1 can advantageously also be oriented
toward a disposable
device.
[00341 The tension indicator 101, in the exemplary embodiment shown in Figs.
lA and 1B, is
embodied for instance as part of an essentially inelastic constricting strap
10 itself, in that it is attached
with excess length at two fixation points, spaced apart from one another in
the elongation direction, to
the elongation portion 100 which is of elastic material. Between the two
fixation points, the
constricting strap 10 there forming the tension indicator 101 is in folded
form, and the excess length is
adapted to the desired defined tension state to be generated, including as a
function of the embodiment
of the elongation portion 100. The attachment to the -fixation points is done
firmly enough, for instance
by gluing, welding (laser welding, ultrasonic welding or the like),
thermoplastic joining methods,
stitching, or the like. In tensing the constricting strap 10, the user can
control the elongation action and
thus the increased tensing force as the folds come closer and closer to the
elongation portion 100 and
can unambiguously tell when the strap portion, spanning the two fixation
points, of the constricting
strap 10 has reached its maximally stretched position. At that moment, the
defined tension state that has
been established and the optimal tensing force of the constricting strap 10
that has been generated are
also reached. For example, ifthe venous blood flow in the vicinity of the
capillaries is to be suppressed
in the transition region between the arterioles and the venules, a suitably
established, defined tension
state of approximately 10 mm suffices, and the person being treated
experiences little stress. In the
vicinity of veins, the blood flow or pulsation can be reached for example by
means of a tension state of
the constricting strap 10 corresponding to a pressure of less than 25 mm ifig.
For this or other
applications, constricting strap devices 1 embodied in accordance with the
aforementioned provisions
can be made available, in which the tension indicator 101 and the elongation
portion 100 are adapted
exactly to the particular intended use.
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10035] In a corresponding way, more than one tension indicator can also be
attached, preferably with
differently defined tension states.
100361 In another exemplary embodiment of the constricting strap device 1, the
constricting strap 10
itself can be made of elastic material. If a tension indicator 101 of defined
excess length is attached to
the constricting strap at fixation points spaced apart from one another in the
elongation direction, then
this tension indicator advantageously comprises flexible, inelastic material,
as in the foregoing
exemplary embodiment. If the constricting strap 10 has stretched, the folded
strap portion of the tension
indicator 101 conforms more and more closely to the outside surface of the
constricting strap 10. The
excess length of the strap portion is adapted to the spanned portion of the
elastic constricting strap,
which portion then is equivalent to the elastic element 20 of the foregoing
exemplary embodiments,
specifically in such a way that when the strap portion is at its full
extension, the desired, defined
tension state is attained without folds along the applicable portion of the
constricting strap 10. In this
state, the fixation of the loop is then done by the user by means of the hook-
and-loop closure, without
tensing the constricting strap even more.
10037] A further embodiment of the constricting strap device 1 is shown in
Figs. 3A and 313. Here the
constricting strap device as in the exemplary embodiment of Fig. lA is
provided with a tension
indicator 101, which is a strap portion of excess length relative to the
unstressed constricting strap and
spans an elastic element 20 between two fixation points, as described in
further detail above. The
closure device 30 as well is embodied as in the exemplary embodiment of Fig.
1A. In addition,
however, there is a usage indicator 40, which in the exemplary embodiment
shown likewise spans the
elastic clement 20, or at least a portion thereof extending longitudinally.
100381 The usage indicator 40 is embodied as a tearing element that extends in
the longitudinal
direction or the elongation direction and that upon elongation of the elastic
element 20 tears in response
to an only slight expenditure of force before the final elongation is
attained, an elongation that is
present in the defined tension state. Similarly to the tearing element,
another element meant to be
irreversibly damaged, such as a lacquer, can be applied. The region in which
the tearing element is
intended to tear during the elongation process can likewise be determined by a
certain excess length
between two fixation points or fastening points of the tearing element at the
elastic element 20; the
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excess length of the tearing element, however, is less than the excess length
of the strap portion
intended for the tension indicator 101. For example, it can be determined in
this way that the tearing
element vi11 already tear if the elongation of the elastic element has
reached, for instance,
approximately ca. 20%, ca. 50% or ca. 80%, or some other small intermediate
value, relative to the
elongation that exists at the defined tension state. In this way, arbitrary
intermediate values for tearing
can be established exactly. Once the tearim2, element of the usage indicator
40 has torn, this means that
the constricting strap device 1 has already been used beforehand and thus is
not being used for the first
time, as is necessary with constricting strap devices 1 that are meant to be
used only once. The tearing
element can for instance comprise an easily tearing paper strip or fiber strip
and is preferably inelastic,
yet flexible.
[0039] If the fixation points of the tension indicator 101 and the fastening
points of the usage indicator
40 in plan view coincide, then both indicators can be produced simply in a
single common work step
and can also be adapted to one another exactly as a functional unit in the
desired way.
[0040] Binding the tearing element used for the usage indicator 40 at the
applicable fixation points or
fastening points can be done in a corresponding way to that described in
conjunction with the elastic
element 20, that is, by gluing, welding (laser welding, ultrasonic welding,
imprinting by means of
printing technology, or the like), stitching, or a thermoplastic joining
technique, or some other suitable
type of fastening. In the enlarged view of detail A, a joining portion
(fastening point) is shown in which
the elastic element 20 is fixed on its top side to the constricting strap 10
and is joined on its underside
with the applicable fastening portion of the tearing element.
100411 In Fig. 3B, the elongated state of the constricting strap 10 is shown,
as it is for example in the
defined tension state. The tearing element of the usage indicator 40 has torn
already as a result of the
elongation, and the two edges at either side of the tear are spaced apart from
one another by a relatively
large elongation gap; that is, the tear has already taken place in a
correspondingly early stage of the
elongation. In the enlarged view of the tearing region (detail B), not only
the portion of the tearing
element that remains (on the closure sidc), but also the elastic element 20
that becomes thinner in the
elongation, and the stretched strap portion of the tension indicator 101 can
be seen.
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[0042] As Figs. 4A and 413 show, the constricting strap device 1 can also,
independently of a tension
indicator 101 or offset from it in the longitudinal direction, have a usage
indicator 40 on the
constricting strap 10; the usage indicator spans an elastic element 20 between
two fixation points or
fastening points with (or alternatively without) excess length, similarly to
what is described for the
version of Figs. 3A, 3B. The constricting strap 10 can, outside the elastic
element 20, again be made of
inelastic, flexible material, or of elastic material.
