U.S. patent application number 17/559697 was filed with the patent office on 2022-07-14 for push device for the axial insertion of an elongate, flexible body.
This patent application is currently assigned to ECP Entwicklungsgesellschaft mbH. The applicant listed for this patent is ECP Entwicklungsgesellschaft mbH. Invention is credited to Daniel Roehn, Heike Schulz.
Application Number | 20220218946 17/559697 |
Document ID | / |
Family ID | 1000006242622 |
Filed Date | 2022-07-14 |
United States Patent
Application |
20220218946 |
Kind Code |
A1 |
Schulz; Heike ; et
al. |
July 14, 2022 |
PUSH DEVICE FOR THE AXIAL INSERTION OF AN ELONGATE, FLEXIBLE
BODY
Abstract
With a push device for the axial insertion of an elongate,
flexible body, in particular of a flexible tube, a cable or similar
elements into a sheath, and axial force introduction unit is
provided, which by way of a non-positive fit or a positive fit,
applies a push movement onto the elongate body and is arranged in a
stationary manner relative to the sheath or is guided on a
predefined movement path.
Inventors: |
Schulz; Heike; (Aachen,
DE) ; Roehn; Daniel; (Aachen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ECP Entwicklungsgesellschaft mbH |
Aachen |
|
DE |
|
|
Assignee: |
ECP Entwicklungsgesellschaft
mbH
Aachen
DE
|
Family ID: |
1000006242622 |
Appl. No.: |
17/559697 |
Filed: |
December 22, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16507782 |
Jul 10, 2019 |
11235125 |
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17559697 |
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13261735 |
Oct 15, 2013 |
10391278 |
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PCT/EP2012/001062 |
Mar 6, 2012 |
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16507782 |
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61451222 |
Mar 10, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 25/0113
20130101 |
International
Class: |
A61M 25/01 20060101
A61M025/01 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 10, 2011 |
EP |
11075043.7 |
Claims
1. A push device system for axial insertion of a blood pump into a
sheath, the sheath comprising proximal-most and distal-most ends
and an inner lumen configured to receive the blood pump through the
proximal-most end, the push device system comprising: a holding
element having proximal and distal regions; and a flange at the
distal region of the holding element, wherein a distal-most end of
the flange comprises a distal surface that is configured to abut a
proximal surface of the proximal-most end of the sheath to couple
the holding element directly to the proximal-most end of the
sheath, wherein the holding element is configured to allow the
blood pump to withstand an axial push force without buckling.
2. (canceled)
3. A push device system according to claim 1, wherein the holding
element is configured to connect to the sheath by way of a central
thread, by way of a bayonet closure, by way of a fit surface, by
way of adhesion forces, by way of a magnetic device, by way of an
eccentric screw connection, by way of a gluing connection, by way
of a cone connection, by way of a snap connection, by way of an
electrostatic connection, by way of elastic holding elements, or by
way of inserting a fit piece of the sheath into a fittingly shaped
recess of the holding element.
4-5. (canceled)
6. A push device system according to claim 1, wherein the holding
element comprises a radial clamping device, which by way of
pressing a clamping tool onto the blood pump in a radial direction,
produces an adhesion to the blood pump, which serves for applying a
push force or holding force in an axial direction of the blood
pump.
7. A push device system according to claim 6, wherein the clamping
tool is configured to roll on the blood pump.
8. A push device system according to claim 7, wherein the clamping
tool comprises at least two friction wheels, and wherein the at
least two friction wheels at least partly lie opposite one another
with respect to the blood pump.
9. A push device system according to claim 8, wherein the at least
two friction wheels are controllable with regard to their
rotation.
10. A push device system according to claim 6, wherein the clamping
tool comprises clamping jaws, and wherein at least one of the
clamping jaws is movable in a guided manner in the axial direction
of the blood pump.
11. A push device system according to claim 10, wherein the
clamping jaws are formed by way of two or more parts of a hollow
cylinder, which is divided into segment bodies, and wherein the
hollow cylinder receives the blood pump.
12-27. (canceled)
28. A push device system according to claim 1, wherein the holding
element is further configured to apply an axial push force on a
catheter coupled to the blood pump.
29. A push device system according to claim 1, wherein the holding
element is configured to limit radial deflections of the sheath by
minimizing a distance between (i) where an axial push force is
applied onto the blood pump and (ii) the proximal-most end of the
sheath.
30. A push device system according to claim 1, wherein the holding
element further comprises one or more recesses for one or more tear
tabs of a second sheath surrounding a catheter coupled to the blood
pump.
31. A push device system according to claim 6, wherein the clamping
tool comprises a compressible foam body.
32. A push device system according to claim 11, wherein the segment
bodies comprise an incompressible material.
33. A push device system according to claim 1, wherein the holding
element further comprises a push cylinder.
34. A push device system according to claim 33, wherein one end of
the push cylinder comprises a disk with a centric opening
surrounded by a peripheral, movable lip, and wherein the opening is
dimensioned in a manner such that an edge of the lip lies on the
blood pump as the blood pump is advanced through the opening.
35. A push device system according to claim 1, wherein the holding
element further comprises a guide body and a drive body, wherein
the guide body comprises a guide rail for receiving the blood pump,
wherein the drive body comprises a recess for receiving the blood
pump, and wherein pressing the drive body against the blood pump in
a radial direction produces an adhesion to the blood pump, which
serves for applying a push force in an axial direction of the blood
pump.
36. A push device system according to claim 35, wherein the guide
body comprises a first material with a first coefficient of
friction, wherein the drive body comprises a second material with a
second coefficient of friction, and wherein the first coefficient
of friction is less than the second coefficient of friction.
37. A push device system according to claim 35, wherein the guide
body comprises the flange of the holding element.
38. A push device system according to claim 35, wherein a lever is
pivotably mounted to the guide body, and wherein the lever is
movable against a spring to press the drive body against the blood
pump in the radial direction.
39. A push device system according to claim 1 further comprising
the blood pump and the sheath.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 16/507,782, filed Jul. 10, 2019, now allowed,
which is a continuation of U.S. patent application Ser. No.
13/261,735, filed Oct. 15, 2013, now U.S. Pat. No. 10,391,278,
which is a national phase entry under 35 U.S.C. .sctn. 371 of
International Application No. PCT/EP2012/001062, filed Mar. 6,
2012, published as International Publication No. WO 2012/119782 A1,
which claims the benefit of U.S. Provisional Application No.
61/451,222, filed Mar. 10, 2011, and claims priority from European
Patent Application No. 11075043.7, filed Mar. 10, 2011, the
disclosures of which are hereby incorporated herein by
reference.
[0002] The invention lies in the field of mechanics, in particular
of mechanical engineering and precision technology. It concerns
those mechanical problems which arise on inserting a flexible,
elongate body into an opening or sheath, due to its tendency to
buckle. To buckle in the context of the present invention is also
to be understood as to abruptly bend, and could also be described
as kinking in a two-dimensional manner, in accordance with the
German word "knicken".
[0003] Such flexible, elongate bodies may for example be cables,
wires, threads, flexible tubings or a combination of such elements,
which are typically to be inserted into sheaths or openings, tubes,
hoses or generally cavities. Such an elongate body may also be a
second sheath which is inserted into a first sheath or is to be
held in a stationary manner with respect to this. If a resistance
against a further pushing movement results when pushing such
bodies, then the body must be prevented from buckling, in order to
permit a further push movement, or corresponding radial deflection
movements must be limited.
[0004] As a whole, amongst other things, it is case of designing
the handling such that it is secure as possible. Thereby, it is
advantageous if on introduction, a certain buckling angle is not
exceeded and a certain bending radius is not fallen short of.
[0005] One application of the invention for example results on
introducing a mechanical pipe cleaning device into a pipe conduit
system, wherein the cleaning device is inserted with a flexible
shaft.
[0006] Typically, such problems also result in medical technology,
if for example a cannula or a catheter is to be inserted into a
body opening, a lumen of the body or an artificial lumen.
[0007] Typical such situations are for example evident from the
international patent application WO 02/43791 A1. There, it is
described that an intravascular pump is introduced into a sheath,
in order finally to be inserted it into a blood vessel of a human
body. A further push movement takes place, also after the pump has
passed the actual sheath region.
[0008] Since such pumps are to be pushed through a blood vessel
over lengths of a few tens of centimeters within the body, one must
reckon with a certain push resistance which renders necessary a
certain push force on inserting. In particular with self-openable
or self-expandable pumps heads, one is to reckon with an increased
push resistance on account of the occurring restoring forces of the
folded or compressed pump head. This is particularly due to the
fact--that because with such pumps, a flexible shaft which is
envisaged for high rotation speeds and a long service life and
which is sensitive to buckling runs within a catheter to be pushed,
it must be ensured that the necessary push force may be applied
onto the catheter without this buckling out or deflecting in
another manner.
[0009] It is therefore the object of the present invention, to
provide a push device for the axial insertion of an elongate,
flexible body into a sheath or for the secure mounting of such a
body with respect to a sheath, which is constructed in an as simple
as possible manner and which permits the simple production of a
push movement and reliably prevents a deflection of the elongate
body.
[0010] According to the invention, this object is achieved with the
features specified in patent claim 1.
[0011] A holding unit is provided for this, which may be designed
as an axial force introduction unit which by way of a non-positive
or positive fit, exerts an axial holding force or push force onto
the elongate body and which is arranged in a stationary manner
relative to the sheath or is led on a defined movement path. Axial
direction in this context is to be understood as the longitudinal
axis direction of the sheath and/or the elongate body.
[0012] Since one may not often engage directly on an end of the
elongate body, an axial force introduction unit must engage on the
elongate body either by way of clamping, i.e., non-positive fit and
corresponding static friction forces, or by way of a positive fit
on the elongate body, inasmuch as this comprises suitable shape
elements on the outer side. A corresponding clamping or a positive
fit then permits the application of an axial force and thus a
holding force and a push movement. For example, one may envisage
the (first) sheath as well as the elongate body which indeed may
also be formed as a (then second) sheath, each comprising a flange
as a fit piece, wherein each of the flanges may be each inserted
into a recess of the push device, or both flanges together maybe
inserted into a single recess of the push device, in particular of
the holding unit or of a guide device for the holding unit which
may then be fastened on the sheath, said insertion being such that
the flanges are fixed in the axial direction and/or radial
direction.
[0013] Advantageously, the fit piece of the sheath is not
displaceable in the push device, disregarding the necessary
mechanical play.
[0014] The fit piece of the sheath may advantageously be rotatable
about the insert direction of the push device in different
positions, in particular with a cylinder-symmetrical design may
also be inserted into the recess at any angular position.
[0015] After inserting the fit piece into the recess, this fit
piece may either still be freely rotatably about the insert
direction or also be non-positively fixed or positively fixed with
respect to the rotation angle.
[0016] The push device may be able to be dismantled for inserting
the flange or flanges into the recess or recesses and for example
be designed as a longitudinally divided hollow body, in particular
hollow cylinder. The recess may also comprise a rinsing device, so
that a rinsing fluid for cleaning the fit piece/pieces may be
introduced there from the outside through a channel.
[0017] Due to the fact that the holding unit/axial force
introduction unit is arranged in a stationary manner to the (first)
sheath, in the push device, the distance and the alignment of the
unit may be selected such that the axial loading of the elongate
body is well controllable and is easy to limit, that only safe
radial forces and radial deflections are applied onto the elongate
body and that the free length of the elongate body between the
axial force introduction unit and the sheath may be defined or
limited.
[0018] Even if the axial force introduction unit is led on a
defined movement path, this path may be accordingly selected such
that the tendency of the elongate body to break out laterally given
a push movement is minimized. Moreover, a mechanical guide for the
elongate body may be well dimensioned and positioned with a given
movement path of the axial force introduction unit.
[0019] The guide of the axial force introduction unit may for
example be realized by way of a single-stage or multi-stage
telescopic guide, for example with concentric tubes, or by way of
guiding in a rail or in a cylindrical cavity.
[0020] Advantageously, one may envisage the push device being
mechanically coupled onto the sheath in a direct manner. This for
example may be achieved by way of a central thread, a bayonet
closure, by the application of adhesion forces, by way of a
magnetic coupling, by way of an eccentric screw connection (for
example by way of screws distributed on the periphery), by way of
gluing, by way of electrostatic attraction forces, by way of
elastic holding elements such as springs, clips or rubber cords or
by way of insertion of a fit piece of the sheath into a fittingly
shaped recess of the holding unit.
[0021] In particular, a deflection of the elongate body on entry
into the sheath should be avoided, since a mechanical guiding and
radial support is usually given or may be simply created in the
sheath or in the flexible tube belonging to the sheath, and the
risk of buckling plays less of a role behind the sheath or the
flexible tube belonging to the sheath, on account of the reduced
restoring forces.
[0022] By way of coupling the push device onto the sheath, the
distance between the holding unit/axial force introduction unit and
the sheath is limited, and a defined guiding of the elongate body
and/or a radial supporting is made possible. Also, it is
particularly simple to fix the movement path of the axial force
introduction unit, in the case that such is provided, with respect
to the sheath.
[0023] For coupling, the sheath may for example comprise a flange
or a plane front plate with an opening, into which the elongate
body is to be introduced, wherein a corresponding counter flange of
the push device may be coupled onto the front plate or the flange.
Thereby, usually releasable connection techniques may be applied or
also the usual joining techniques such as gluing or other adhesive
measures, which advantageously however are to create a releasable
connection.
[0024] If by way of the push device, only the first sheath and an
elongate body, for example a second sheath, are to be axially
pressed against one another, then a flange or a front plate of the
first sheath on the one hand and a flange of the second sheath or
of another elongate body may be fixed to one another. However, for
example a connection may also be created by way of insertion into
one another, which is held by a non-positive or positive fit. What
is important here, is that the forces for holding the connection
are greater than the forces which are necessary for pushing the
elongate body, so that the connection is not unintentionally
released on pushing the elongate body.
[0025] A mechanical coupling may advantageously also be provided
directly between the axial force introduction unit and the sheath.
A radial guiding between the axial force introduction unit and the
sheath may be minimized or completely left out by way of this. The
constructional size of the push device may thus also be kept very
low.
[0026] Advantageously, the push device may comprise a guide device
which may be fastened on the sheath by way of a coupling and which
radially supports the elongate body, wherein the axial force
introduction unit is arranged either in a stationary manner
relative to the guide device or is guided on a defined movement
path. In this case, the guide device is provided between the axial
force introduction unit and the sheath and either serves for
bridging a distance between the axial force introduction device and
the sheath, and with this rendering the application of a push force
manageable, and/or with a given small distance between the axial
force introduction unit and the sheath, to design this distance by
way of the guide device, in a manner such that the elongate body
may in no case radially deflect with this distance.
[0027] The axial force introduction unit may advantageously
comprise a radial clamping device which by way of pressing a
clamping tool onto the elongate body in the radial direction
produces a bond which serves for applying a push force or holding
force in the axial direction. The clamping tool may be designed in
a movable manner for example and roll on the elongate body.
[0028] In particular, at least one, on particular two, three or
four friction wheels may be provided as a clamping tool, which lie
radially opposite one another at least partly with respect to the
elongate body. The elongate body may then be clamped between the
friction wheels and be radially supported by these. A push movement
may be applied onto the elongate body by way of a drive of the
friction wheels. One may also arrange several sets of friction
wheels or knurled wheels one after the other in the longitudinal
direction of the elongate body.
[0029] One may also envisage the friction wheels or at least one of
them comprising a freewheel means which permits a rotation in each
case in only one direction, so that for example the friction wheels
block and push the elongate body upon advancing the push device,
and rotate the friction wheels in a manner such that the push
device may be displaced with respect to the elongate body without
force, upon retracting the push device. With this, the elongate
body may for example be pushed in steps, for example by hand or by
way of another drive, by way of displacement of the push
device.
[0030] Such drives may for example be provided by way of electric
motors on the friction wheels, so that the push device may stand
still in a stationary manner. A reduced space requirement results
with the application of the push device by way of this.
[0031] Generally, it may a make sense for the friction wheels to be
able to be controlled with regard to their rotation, i.e., either
be actively drivable or for example lockable in a controlled manner
from the outside. The continuous drive of the push device by way of
a rotation drive of the friction wheels for example also permits
the control of the introduced push force in dependence on the
advance, the advance speed or a detected counter-force. With this,
one may prevent a catheter for example, which is inserted into a
body, from being simply pushed further in the case that an
increased resistance arises due to hitting a vessel wall. A
suitable control may stop the advance procedure or slow it down. A
suitable control which may designed in an electronic manner, may
either control the advance force or the advance speed either
according to a defined curve/characteristics or in dependence on
the push resistance.
[0032] One may also advantageously envisage the clamping tool being
provided with clamping jaws radially on both sides of the elongate
body, and the clamping jaws with the elongate body fixed between
them being movable in a guided manner with respect to the sheath
and/or a guide device, essentially in the axial direction the
elongate body.
[0033] The clamping jaws may thereby be designed as two or more
bodies which are movable relative to one another in the radial
direction with respect to the elongate body, and which for example
may also be designed in a compliant manner, in particular softer
that the elongate body itself. For this purpose, the clamping jaws
should consist of a soft material such as plastic or elastomer for
example or a coated with such a material. One may also envisage
only a few of the clamping jaws being designed in a movable manner,
whilst the other clamping jaws are fixed in a stationary
manner.
[0034] For example, two, three, four, five or more clamping jaws
may be provided, which lie opposite one another on the periphery of
the elongate body.
[0035] Particularly advantageously, the clamping jaws may be formed
by two or more parts for example of a hollow cylinder or of any
other shape corresponding to the elongate body, said shape
receiving the elongate body. The clamping jaws may then form sector
bodies of the hollow cylinder. A hollow cylinder in this context is
to be understood as a body which has an in particular cylindrical,
continuous opening. Such a body may for example also have a
cylindrical shape on its outer side. Instead of a hollow cylinder,
one may also apply a different type of body with a continuous
opening.
[0036] The respective sector bodies may for example have the same
length as the hollow cylinder and be distributed on the periphery
of the elongate body. The push device may also be designed in a
manner such that first clamping jaws are arranged in a non-movable
manner in the axial direction and consist of a material which has a
low friction compared to the material of the elongate body. Second
clamping jaws in contrast are axially movable and have a greater
friction coefficient compared to the material of the elongate body,
so that the elongate body may be pushed by the second clamping jaws
against the first clamping jaws and may be slidingly moved in the
axial direction on these, as on a guide rail. In this manner, the
radial guiding for the elongate body may be realized by the
clamping jaws, as well as the advance in the axial direction by way
of individual ones of the clamping jaws.
[0037] The holding device may comprise a clamping device for the
elongate body, said clamping device able to be clamped by hand by
way of radial pressure and releasing the elongate body with the
absence of an external pressure force. Spring elements may serve
for this, which automatically opens the holding device/clamping
device.
[0038] A method for realizing the invention envisages the speed of
the advance of the elongate body being controlled by a control
device. Thereby the speed may be activated as a constant speed or
also according to defined speed characteristics/time
characteristics or speed characteristics/displacement
characteristics.
[0039] If unforeseen resistances to the elongate body result with
the advance movement, for example if this is inserted into a blood
vessel of a patient, then the respective drive force may be
increased by way of the control, in order to ensure the advance
speed according to the defined characteristics.
[0040] However, one may also envisage a control which keeps the
advance resistance or the advance force constant, so that the drive
force onto the push device is reduced with the occurrence of
increased push resistances on the elongate body, for example in
order to prevent a buckling of the elongate body due to the
increase of push forces, or with a medical application, for example
if the elongate body is a catheter which is introduced into a body
opening, to prevent an injury of the patient. In this case, the
advance may also be completely stopped by way of the control, and
the elongate body retracted a little. The increase of the push
resistance may be signaled by a light on the outside on the push
device as well as by way of an acoustic signal transducer.
[0041] Inasmuch as this is concerned, the push resistance may be
measured and the push movement may be controlled with or without a
closed loop in dependence on the push resistance. For this, a
drive, for example an electric or pneumatic drive, and a suitable
sensor, for example a current sensor for measuring the magnitude of
the applied current strength, a voltage senor or a suitable
pressure sensor with the use of pneumatics, as well as a control
device and correspond signal transducers are to be provided for
this.
[0042] The invention is hereinafter shown by way of one embodiment
example and described hereinafter. Thereby are shown in:
[0043] FIG. 1 the application of a heart catheter pump with a human
heart,
[0044] FIG. 2 a pump device with a heart catheter pump and with a
drive shaft which runs in a hose-like casing,
[0045] FIG. 3 a push device in a three-dimensional view,
[0046] FIG. 4 the push device of FIG. 3 in a lined
representation,
[0047] FIG. 5 a longitudinal section through the device of FIG.
4,
[0048] FIG. 6 a guide device designed as a hand grip, in a
longitudinal section with the front end of a sheath,
[0049] FIG. 7 a guide device without an inserted sheath,
[0050] FIG. 8 the guide device of FIG. 7 in a front view,
[0051] FIG. 9 a push device with at least two friction wheels,
[0052] FIG. 10 a plan view of the device according to FIG. 9, along
the line indicated in FIG. 3 at IV-IV,
[0053] FIG. 11 a similar view to that in FIG. 10, with four
friction wheels distributed around the elongate body,
[0054] FIG. 12 a similar view as in FIG. 11, additionally with
electromechanical drives of the friction wheels,
[0055] FIG. 13 an arrangement with two friction wheels which have
friction surfaces which are concave in cross section,
[0056] FIG. 14 a push device similar to that of FIG. 9, with which
the friction wheels only serve for the radial support and a
different type of axial force introduction is envisaged,
[0057] FIG. 15 a view of the device of FIG. 14 along the line which
is characterized there at IX-IX,
[0058] FIG. 16 a further variant of the axial force introduction
unit,
[0059] FIG. 17 a cross section of the axial force introduction unit
of FIG. 16,
[0060] FIG. 18 a further design of the axial force introduction
unit,
[0061] FIG. 19 a cross-sectional view along the line XIII-XIII of
FIG. 18,
[0062] FIG. 20 another variant of the axial force introduction unit
of FIG. 18,
[0063] FIG. 21 in a longitudinal section, a push device with
axially stationary and axially movable clamping jaws,
[0064] FIG. 22 a cross section of the device of FIG. 21 along the
line characterized there at XVI-XVI and
[0065] FIG. 23 a detail of the drive device for a push device.
[0066] FIG. 1 in a longitudinal section shows a blood vessel 1 with
a first sheath 2 in the form of a flexible tubing or hose and which
with its distal end projects into the blood vessel 1 in the
direction of a heart chamber 3 up to the aortic arch. The sheath 2
is introduced through an opening 4 into the blood vessel 1 and is
ideally sealed there. The first sheath 2 at its proximal (outside
the body) end 5 comprises a flange 6.
[0067] A heart catheter 8 which is designed in a hollow manner and
in which a drive shaft for a heart pump 9 which is represented in a
dashed manner, is shown at the distal end 7 of the sheath 2, also
in a dashed manner. The pump 9 is inserted into the heart chamber 3
and comprises a rotor which rotates with a high rotation speed,
driven by the shaft, in order to deliver blood out of the heart
chamber into the blood vessel 1.
[0068] An elongate body 10 is represented at the proximal end 5 of
the sheath 2, in front of the flange 6, and is to be introduced
into the sheath 2 in the direction of the arrow 11. The elongate
body 10 is shown only in sections there. In the shown case, the
elongate body is formed for example by way of the heart catheter 8
which together with the flexible drive shaft arranged therein
represents a flexible elongate body which is to be pushed through
the sheath 2 into the blood vessel 1 and further into the heart
chamber 3. Depending on the point, at which the heart catheter is
inserted into a blood vessel (typically at a femoral artery), the
advance displacement for the catheter is more than 80 cm in the
patient body.
[0069] The elongate body 10 may consist of a heart catheter 8 which
is surrounded by a second, flexible-tube-like sheath. This second
sheath is then designed such that it keeps the radially
compressible pump compressed. The second sheath may usefully
already be premanufactured with the heart catheter 8 and the pump
before use on a patient body.
[0070] The second sheath may then be axially held onto the first
sheath and fixed there, for example by way of the push device
according to the invention. Whilst the second sheath is pressed
axially against the first sheath, the heart catheter may then be
pushed through the second sheath into the first sheath and by way
of this may be pushed into the blood vessel.
[0071] A push device according to the invention may likewise be
applied with the axial insertion of the heart catheter into the
second sheath. This push device is then applied onto the second
sheath opposite to the first sheath and encloses the section of the
heart catheter in front of the second sheath.
[0072] FIG. 2 shows a more detailed, but schematic representation
of the pump catheter 8 with the flexible drive shaft 12. This is
connected proximally to a drive in the form of a motor 13 and
distally to a drive hub 14 within a pump housing 15. The hub 14
carries rotor blades 16 for delivery of a fluid or blood.
[0073] FIG. 3 shows one design of a push device in a
three-dimensional view.
[0074] FIG. 4 shows the same view as an outline drawing and FIG. 5
a longitudinal section.
[0075] A guide device 56 in the form of a hollow cylinder divided
into two, with a lower half 57 and with an upper half 58 is shown.
The cylindrical cavity 59 receives the elongate body 60 to be
pushed, as well as a second sheath and supports it in a radial
manner. The upper half 58 is connected to the lower half 57 via
screws 61, 62 which slide in elongate holes. The elongate holes are
widened at one end, so that the upper half may be removed after
displacing this. By way of this, the elongate body with the second
sheath, just as the first sheath, may be inserted with its flange
64 without any problem, and the front-side end 63 of the sheath
(cf. FIG. 6) in particular the flange 64 may be inserted into the
undercut cavity 67 of the hollow cylinder 56 (FIGS. 6, 7). A
reliable, releasable coupling of the guide device onto the sheath
is ensured by way of this. A channel of a rinsing device which runs
out into the cavity 67 is indicated in FIG. 5 with the reference
numeral 66.
[0076] A holding unit/axial force introduction device may comprise
recesses for tear tabs 65 of a second sheath, if the second sheath
is designed as a so-called "peel-off sheath". This means that the
second sheath on account of its material structure (molecular
alignment, anisotropic structure) and/or the incorporation of
predefined breakage locations (perforation), is set up to be
longitudinally torn open and removed, after pushing through a heart
catheter.
[0077] FIG. 8 shows a further illustration of a cross section of
FIG. 6.
[0078] FIG. 9 specifically shows another embodiment of an advance
device, wherein the flange 6 of the first sheath 2 is shown on the
left side and the push device in the right region of the figure.
The push device comprises a tubular housing 17 whose distal end 18
may be pushed onto the flange 6 and is fixed there with respect to
the flange 6. The fixation may for example be realized by way of a
central thread on the flange 6 as well as on the housing end 18 or
by way of a bayonet connection between these parts. Other types of
screw connections or and other bonding connections such as gluing
or magnetic bonding are conceivable. It makes sense if the
[0079] connection between the push device and the flange 6 of the
sheath can be easily released again. The push device may also
comprise a cavity for receiving and fixing the flange 6, as well as
an opening for incorporating the flange into the cavity,
[0080] At least two friction wheels 19, 20 as part of an axial
force introduction device or holding unit are rotatably mounted
within the housing 17 and on their periphery, each have a friction
coating 19a, 20a which has a greater coefficient of friction
compared to the material of the elongate body 10. The elongate body
10 is typically clamped in between the friction wheels 19, 20. The
elongate body may thereby be a catheter as well as a second
sheath.
[0081] The friction wheels 19, 20 may for example be controllable
with regard to the rotation ability. If they are blocked, as a
whole the elongate body may be advanced in the direction of the
arrow 21 by way of axial movement of the push device together with
the friction wheels if these are movable in a guided manner in the
housing 17. If the push device is retracted opposite to the
direction of the arrow 21, then the friction wheels 19, 20 may be
released for example by way of a control or a freewheel, so that
with this movement of the push device, the elongate body 10 is not
caught, but remains in the position relative to the sheath 2. The
friction wheels 19, 20 may be blocked again before a renewed
advance of the push device in the direction of the arrow 21. For
example, for realizing such a drive mechanism, the housing 17 may
be axially advanceable and retractable on a connection of the
flange 6.
[0082] Another variant of the drive may envisage the friction
wheels 19, 20 being able to be driven in the direction of the
arrows 22, 23 when the push device is stationary, in order to push
the elongate body 10 in the direction of the arrow 21. This variant
has the advantage that the speed of the friction wheels 19, 20 or
the torque may be detected for example by way of the current of an
electric motor driving the friction wheels. The respectively
detected variables may be used for controlling the advance speed of
the elongate body or for the control of the push force, in order to
limit this and thus to prevent injuries on inserting a catheter
into a lumen within a body of a patient. Alternatively, the push
force may also be limited by way of a slip coupling for
example.
[0083] FIG. 10 in a plan view along the line IV-IV according to
FIG. 3 shows the two friction wheels 19, 20 as well as the elongate
body 10 which is clamped between them.
[0084] In FIG. 11 it is shown that indeed also more than two, for
example four friction wheels 19, 20 may be provided distributed on
the periphery of the elongate body. This may be three, five or six
friction wheels for example.
[0085] A rotatable mounting is represented schematically for each
individual friction wheel by way of a stylized pivot. The friction
wheels may be drivable for example by way of individual motoric
drives or together via a coupling gear. One may also envisage only
individual ones or only a single one of the friction wheels being
drivable. The other friction wheels in this case would
automatically co-rotate with the drive of a single friction
wheel.
[0086] FIG. 12 shows an example of an implementation of a drive via
two electric motors 24, 25.
[0087] Two friction wheels are represented in the FIGS. 4 to 6
schematically as cylindrical wheels, as the case may be with a
friction coating.
[0088] In contrast to this design, a concave outer peripheral
surface of the friction wheel 19', 20' may also be provided
according to FIG. 13. The concave surfaces 26 are designed in a
manner such that they snugly bear on the elongate body 10 and also
hold this laterally, so that one may ensure a reliable radial
guiding of the elongate body already with two friction wheels.
[0089] FIG. 14 shows an advance device with an axial force
introduction unit 27 in the form of a push cylinder 28 which on a
guide body 29 is displaceable to and fro in the direction of the
arrow 30. The push cylinder 28 at one end comprises a bead-like
disk 31 with a centric opening which is surrounded by a peripheral,
movable lip 32. The opening is dimensioned in a manner such that
the edge of the lip 32 lies on the elongate body 10. If the push
cylinder 28 is pushed to the sheath 2, then the lip 32 is deflected
in the direction of the arrow 33, and the centric opening of the
bead disk 31 reduces in size and clamps the elongate body 10. This
is then caught in the direction towards the sheath 2 and is
displaced to there.
[0090] With a withdrawal movement of the push cylinder 28, the lip
32 moves in the direction of the arrow 34, so that the centric
opening of the bead disk 31 is enlarged and the push cylinder 28
may be retracted with respect to the elongate body 10 which remains
stationary.
[0091] In this manner, the elongate body 10 may be moved into the
sheath 2 in steps. The movement of the push cylinder 28 is guided
on the guide body 29, so that the movement path of the axial force
introduction unit is fixed. The elongate body moreover is led in a
cylindrical opening 35 of the guide body 29 and further in the
direction of the sheath 2 through two or more friction wheels 19,
20 which are movable in a freely rotatable manner and lie opposite
one another. A guiding by way of several groups of friction wheels,
said groups lying axially behind one another, may be provided on
the one hand, or exclusively by way of a long, hollow-cylindrical
opening up to the flange 6 of the sheath 2.
[0092] Opposite the flange 6 of the sheath 2 lies a similarly
constructed flange 36 of the guide body 29, so that the two flanges
6, 36 may be connected to one another by way of a screw connection
which is shown by way of example by way of a dashed line 37. For
this, several screws may be distributed on the periphery of the
flange, in particular in a symmetrical manner.
[0093] A cross section along the section line IX-IX in FIG. 14 is
represented in FIG. 15, with the centric opening 15 in the guide
body 29 which is surrounded by the cylinder 28 of the axial force
introduction unit 27.
[0094] FIG. 16 shows another variant of an axial force introduction
device which may be used for example in the push device according
to FIG. 14 instead of the axial force introduction device 27. A
push cylinder 28' is shown in FIG. 16, which may be guided in an
axial manner on the guide body 29. A foam body 38 serves for
clamping in the elongate body 10 and may be pressed together
radially by way of pressure in the direction of the arrows 39, 40,
in order to compress the opening 35' and to firmly clamp the
elongate body in the opening 35'. For example, the foam cylinder 38
may be pressed together by hand, whilst simultaneously a push
movement is carried out in the direction to the sheath 2. With
this, the elongate body may be pushed somewhat into the sheath
2.
[0095] On retracting, the radial pressure on the foam cylinder 38
is reduced, so that the opening 35' elastically enlarges again in
the radial direction and the elongate body is released. Thus, the
axial force introduction unit may then be retracted proximally with
respect to the elongate body.
[0096] FIG. 17 shows a cross section through the foam cylinder 38
with the opening 35'.
[0097] A further variant of an axial force introduction unit is
represented in FIG. 18, with a solid push cylinder 41 which
comprises a guide tube 28'' which may be guided on the guide
cylinder 29 as is represented in FIG. 14.
[0098] In the case which is represented in FIG. 18, the cylinder 41
itself is manufactured from an incompressible material, but is
divided in the longitudinal direction into two halves, so that two
segment bodies of the cylinder 41 result, as is represented in
FIGS. 19 and 20 in different variants. Firstly, according to FIG.
19, the cylinder 41 may be completely cut through and consists of
two halves 44, 45 connected only by springs 42, 43. These in the
relaxed condition of the springs 42, 43 have a distance which is
dimensioned such that the elongate body 10 is located in the
central recess 35'' with play. If the halves 44, 45 are pressed
together against the force of the springs 42, 43, the elongate body
may be clamped in the opening 35''. The elongate body may then be
advanced in the clamped condition. The two halves 44, 45 of the
cylinder 41 may for example be pressed together by hand on
manipulating the push device, and may be let go when retracting the
cylinder 41.
[0099] FIG. 20 shows a similar design form, wherein the cylinder 41
is not completely separated into two halves, but a film joint 46
remains on one side of the cylinder 41, and this joint permits the
two halves 44', 45' to be folded open. One may also provide a
separate hinge instead of the film joint 26. The manner of
functioning on clamping the elongate body corresponds to that
represented by way of FIG. 19.
[0100] FIG. 21 shows a push device which is different from the
devices which are represented in the previous figures. Here, a
flange 46 of a guide body 47 is fastened on a sheath 2, and to be
more specific, on its flange 6. The guide body 47 comprises a guide
rail for the elongate body 10 which for example may be given by a
semi-cylindrical or part-cylindrical recess, in which the elongate
body 10 may lie.
[0101] FIG. 22 in a cross section shows the guide body 47 with the
part-cylindrical recess 48 in which the elongate body 10 lies.
[0102] In FIG. 21, a drive body 49 is represented above the guide
body 47, and this drive body forms the axial force introduction
unit. This drive body 49 for example likewise comprise a part
cylindrical recess which receives the elongate body 10 at least
partly. The drive body 49 may be displaced proximally or distally
in the axial direction, represented by the double arrow 50. A
particular feature of the guide body 47 and of the drive body 49
may for example be realized by way of the friction between the
drive body 49 and the elongate body 10 on account of the material
selection with higher coefficients of static friction, being
significantly larger than the friction between the elongate body 10
and the guide body 47. For example, the guide body 47 may consist
of a particularly smooth material with a low coefficient of
friction, for example PTFE or may be coated with such a
material.
[0103] The drive body 49 for its part may consist of a material
which has a greater coefficient of friction compared to the
elongate body 10, such as of an elastomer, particularly rubber or
silicone rubber. By way of this, if the drive body 49 is pressed
radially against the elongate body 10, the elongate body 10 may be
moved axially in the fixed guide rail by way of displacement of the
drive body in the axial direction.
[0104] Usefully, on introducing the elongate body 10 into the
sheath 2, this is simultaneously pressed onto the drive body and
moves this distally in the direction of the sheath 2. On retracting
the drive body away from the sheath 2, the pressing force on the
elongate body is reduced, so
[0105] that this is not caught and remains in the sheath 2. In this
manner, the elongate body may be moved along in the sheath 2 in
steps.
[0106] According to FIG. 23, a pistol-like handgrip may also be
provided on the guide body 47 and this hand grip comprises a lever
51 which is movable against a spring 52. The lever 51 is pivotably
mounted and comprises a plunger 53 which presses against a clamping
disk 54, clamps this with respect to the drive body 49 and
thereupon effects a push movement of the drive body 49. The
clamping disk is spring-loaded opposite to the direction of the
arrow 55.
[0107] The device shown in the FIGS. 9-23 may on the one hand be
used for a second sheath, in order to press this as an elongate
body against a first sheath and to permit the pushing-through of a
pump head with a minimized risk of a buckling of the pump catheter.
On the other hand, this device may also be connected proximally to
a holding device of a second sheath which is shown in the FIGS.
3-8, in order to permit the inserting of a catheter (as the case
maybe with a pump head) into the second sheath without a buckling.
Thus, two push devices may be combined with one another in this
manner.
* * * * *