U.S. patent application number 11/573930 was filed with the patent office on 2008-02-14 for implantabel medical site.
Invention is credited to Jean-Francois Chantriaux, Marie-Pierre Marthe Diedonnee.
Application Number | 20080039772 11/573930 |
Document ID | / |
Family ID | 34959085 |
Filed Date | 2008-02-14 |
United States Patent
Application |
20080039772 |
Kind Code |
A1 |
Chantriaux; Jean-Francois ;
et al. |
February 14, 2008 |
Implantabel Medical Site
Abstract
An implantable device (1) for injecting and/or drawing fluid
having a housing (2) with a chamber (2A) formed therein. The
housing (2) includes a proximal wall (4) and a distal wall (5)
between which a side wall extends, and an aspiration zone (7)
designed to be perforated by a hollow needle for injecting and/or
drawing fluid into the chamber (2A). The aspiration zone (7)
extends simultaneously on the proximal wall (4), the side wall and
the distal wall (5). The device (1) has a shield (13) made of a
material not perforable by a hollow needle inside the chamber (2A)
to prevent the housing (2) from being perforated by a hollow
needle.
Inventors: |
Chantriaux; Jean-Francois;
(Montauban, FR) ; Diedonnee; Marie-Pierre Marthe;
(Montauban, FR) |
Correspondence
Address: |
POWELL GOLDSTEIN LLP
ONE ATLANTIC CENTER
FOURTEENTH FLOOR 1201 WEST PEACHTREE STREET NW
ATLANTA
GA
30309-3488
US
|
Family ID: |
34959085 |
Appl. No.: |
11/573930 |
Filed: |
August 18, 2005 |
PCT Filed: |
August 18, 2005 |
PCT NO: |
PCT/FR05/02104 |
371 Date: |
June 14, 2007 |
Current U.S.
Class: |
604/27 |
Current CPC
Class: |
A61M 39/0208 20130101;
A61M 2039/022 20130101; A61M 2039/0226 20130101; A61M 39/045
20130101 |
Class at
Publication: |
604/027 |
International
Class: |
A61M 25/00 20060101
A61M025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 19, 2004 |
FR |
PCT/FR04/02161 |
Claims
1. An implantable device for injecting and/or extracting fluid
either into or from an organ or vessel of the body of a human or
animal patient, or into or from an inflatable and/or deflatable
compartment of a surgical implant, said device comprising: (a) a
housing having (i) a chamber connected to a catheter, wherein the
catheter is connected either to the organ or vessel or to the
compartment, (ii) a proximal wall and a distal wall with a side
wall extending between the proximal wall and the distal wall, (iii)
a puncture zone capable of being pierced by a hollow needle to
inject and/or extract fluid into or from the chamber, the puncture
zone being shaped as to extend simultaneously at least over the
proximal wall, the side wall, and the distal wall; and (b) a screen
made of a material that is not pierceable by the hollow needle and
is located within the chamber to prevent the housing from being
pierced through by the hollow needle.
2. The device of claim 1, wherein the distal wall is substantially
planar and is defined laterally by two side edges, while the
proximal wall and the side wall form a surface of revolution
interconnecting the side edges.
3. The device of claim 1, wherein the proximal, distal, and side
walls form a surface that is substantially polyhedral.
4. The device of claim 1, further comprising a duct connecting the
chamber to the outside of the device, the duct extending
longitudinally along a first axis and connecting to the catheter,
proximal, distal, and side walls being shaped and arranged so that
the housing substantially presents symmetry about a second axis,
the second axis is substantially parallel to the first axis.
5. The device of claim 4, wherein the proximal, distal, and side
walls form a surface that is substantially spherical.
6. The device of claim 4, wherein the proximal, distal, and side
walls form a surface that is substantially ovoid.
7. The device of claim 4, wherein the proximal, distal, and side
walls form a surface that is substantially pear-shaped.
8. The device of claim 4, wherein the proximal, distal, and side
walls form a surface that is substantially cylindrical.
9. The device of claim 1, wherein the puncture zone extends over
substantially all of the proximal, side, and distal walls.
10. The device claim 1, wherein the puncture zone comprises a
self-sealing membrane.
11. The device of claim 1, wherein the housing is constructed from
a frame made of a material that is substantially not pierceable by
the hollow needle and is covered by at least one envelope made of a
self-sealing material, the frame is pierced so that, in cooperation
with the envelope, the frame forms the puncture zone.
12. The device of claim 11, wherein the frame is substantially
rigid lattice.
13. The device of claim 1, wherein the screen is a wheel having at
least one blade.
14. The device of claim 13, wherein the blades wheels comprises at
least four blades which are at least four in number, and are
regularly spaced apart angularly.
15. The device of claim 13, wherein the bladed wheel is mounted to
rotate within the chamber.
16. The device of claim 1, wherein the chamber is defined by a
chamber wall, and the screen comprises at least one stop panel for
the hollow needle mounted to bear slidably against the wall of the
chamber in such a manner that the wall can be moved within the
chamber under the effect of thrust exerted by the hollow
needle.
17. The device of claim 1, wherein the chamber is defined by a
chamber wall, and the screen comprises at least one stop panel for
the hollow needle, the panel being deformable under the effect of
thrust exerted by the hollow needle.
18. The device of claim 17, wherein the panel is deformable in
bending.
19. The device of claim 17, wherein the panel comprises a plurality
of substantially rigid unitary elements linked by flexible links to
form the panel.
20. The device of claim 1, wherein the screen comprises a flexible
membrane of shape that substantially matches the shape of the wall
of the chamber, the membrane being disposed freely within the
chamber and being deformable under the effect of thrust exerted by
the hollow needle.
21. The device of claim 20, wherein the membrane presents shape
memory.
22. The device of claim 20, wherein the membrane is made by weaving
a substantially rigid material.
23. The device of claim 1, wherein the chamber is defined by a
chamber wall, and the screen presents a first face facing the
chamber wall and an opposite second face, the first face is
provided with access means allowing the hollow needle to pass
through the screen in the first face to second face direction,
while the second face is provided with blocking means for
preventing the needle from passing through the screen in the second
face to first face direction.
24. The device of claim 23, wherein the screen comprises a series
of unitary elements disposed side by side and urged resiliently
against one another, the elements cooperating in pairs to define
between them and facing the wall of the chamber corresponding
converging paths for the hollow needle such that inserting the
hollow needle into a converging path leads to the corresponding
elements being spaced apart relative to each other, thereby
enabling the needle to pass into the chamber, the set of convergent
paths forming the first face, the unitary elements also cooperating
in pairs, opposite from the converging paths, to define between
them obstacles to the needle passing between them, the set of
obstacles forming the second face.
25. The device of claim 23, wherein the screen comprises a
plurality of tubular elements of substantially converging shape
engaged one in another, to form a substantially tubular structure
presenting an outside face forming the first face and an inside
face forming the second face.
26. The device of claim 23, wherein the screen comprises a
plurality of slats that overlap one another in part around a
substantially tubular outline presenting an outside face, forming
the first face, and an inside face, forming the second face.
27. The device of claim 1, wherein the screen comprises a plurality
of particulate elements disposed freely within the chamber, the
particulate elements being present in sufficient number for
insertion of the hollow needle into the chamber to lead, at least
locally, to the particulate elements blocking mutually against one
another, thereby together forming a stop assembly for the
needle.
28. The implantable device of claim 1, wherein the surgical implant
comprises a gastroplasty ring.
29. An implantable device for injecting medication into a vein or
an artery and/or for taking blood from vein or artery, thereby
forming an artificial vein or artery the device comprising: (a) a
housing having (i) a chamber connected to a catheter, wherein the
catheter is connected either to the organ or vessel or to the
compartment. (ii) a proximal wall and a distal wall with a side
wall extending between the proximal wall and the distal wall. (iii)
a puncture zone capable of being pierced by a hollow needle to
inject and/or extract fluid into or from the chamber, the puncture
zone being shaped as to extend simultaneously at least over the
proximal wall, the side wall, and the distal wall: and (b) a screen
made of a material that is not pierceable by the hollow needle and
is located within the chamber to prevent the housing from being
pierced through by the hollow needle.
Description
TECHNICAL FIELD
[0001] The present invention relates to the general technical field
of devices for inserting under the skin of a human or animal
patient in order to be capable of being pierced subsequently by a
hollow needle through the skin of the patient for the purpose of
introducing and/or extracting substances into or from the body of
the patient, while limiting cutaneous trauma repeated at the same
location. Such devices are generally referred to as implantable
sites or else as access ports.
[0002] The present invention relates more particularly to an
implantable device for injecting and/or extracting fluid either
into or from an organ or a vessel of the body of a human or animal
patient, or else into or from an inflatable and/or deflatable
compartment of a surgical implant, said device comprising a housing
within which there is formed a chamber for connection to a
catheter, said catheter itself being for connection either to said
organ or vessel or else to said compartment, the housing having a
proximal wall and a distal wall between which there extends a side
wall, said housing having a puncture zone designed to be pierced by
a hollow needle in order to inject and/or extract fluid into or
from the chamber.
PRIOR ART
[0003] Known implantable sites are generally in the form of a
housing including an end wall from which there extend side walls
whose free ends define a proximal opening.
[0004] The end wall and the side walls are made of solid and rigid
material, such as titanium, to ensure that they cannot be pierced
by a needle. The proximal opening is closed by a substantially
plane membrane of self-sealing material, thus forming a
"septum".
[0005] Although such devices generally give satisfaction, they
nevertheless present drawbacks that are not negligible.
[0006] Thus, although those known devices are relatively bulky and
thus potentially uncomfortable for the patient, they provide an
injection area that is small, thus exposing the surrounding tissue
to risks of lesions by perforation, since the probability of the
practitioner piercing away from the "septum" is far from being
negligible.
[0007] Furthermore, those known devices are liable to turn over
under the skin, under the effect of movements of the patient. In
extreme circumstances, the site can thus be turned through
180.degree., thereby totally masking the "septum". The device as
turned over in this way then becomes unusable, which requires new
surgery to implant a new device.
[0008] In order to remedy that problem of the site turning over,
proposals have been made to bind the site to surrounding biological
tissues. In order to achieve such fastening, known devices are
provided with holes that enable them to be sutured to neighboring
biological tissues.
[0009] Nevertheless, such a solution is not very satisfactory,
since it requires a relatively large surgical approach path, and
surgery that is longer and difficult, while increasing patient
discomfort and the risk of infection.
SUMMARY OF THE INVENTION
[0010] Consequently, the objects given to the invention seek to
propose a novel implantable fluid injection and/or extraction
device capable of remedying the various drawbacks mentioned above
and facilitating the operations of implanting the device, and also
of injecting and/or extracting fluid, regardless of the orientation
of the device under the skin of the patient, and without risk of
injuring the patient with the needle.
[0011] Another object of the invention is to propose a novel
implantable fluid injection and/or extraction device that enables
the practitioner to pierce the skin using a technique that is
substantially similar to that implemented when piercing a natural
vein.
[0012] Another object of the invention is to propose a novel
implantable fluid injection and/or extraction device that reduces
the risks and drawbacks associated with body movements of the
patient.
[0013] Another object of the invention is to propose a novel
implantable fluid injection and/or extraction device that does not
need to be sutured to the body of the patient.
[0014] Another object of the invention is to propose a novel
implantable fluid injection and/or extraction device that is of
particularly simple and compact design.
[0015] Another object of the invention is to propose a novel
implantable fluid injection and/or extraction device that is
particularly lightweight.
[0016] Another object of the invention is to propose a novel
implantable fluid injection and/or extraction device that is
particularly reliable.
[0017] The objects given to the invention are achieved with the
help of an implantable device for injecting and/or extracting fluid
either into or from an organ or vessel of the body of a human or
animal patient, or into or from an inflatable and/or deflatable
compartment of a surgical implant, said device comprising a housing
within which there is formed a chamber designed to be connected to
a catheter, said catheter itself being designed to be connected
either to said organ or vessel or to said compartment, the housing
comprising a proximal wall and a distal wall with a side wall
extending between them, said housing including a puncture zone
designed to be capable of being pierced by a hollow needle in order
to inject and/or extract fluid into or from the chamber, the device
being characterized in that said puncture zone is shaped in such a
manner as to extend simultaneously at least over the proximal wall,
the side wall, and the distal wall, said device including a screen
made of a material that is not pierceable by the hollow needle and
disposed within the chamber in order to prevent the housing being
pierced right through on being pierced by the hollow needle.
BRIEF SUMMARY OF THE DRAWINGS
[0018] Other objects and advantages of the invention appear better
on reading the following description and with the help of the
accompanying drawings, given in purely illustrative and
non-limiting manner, and in which:
[0019] FIG. 1 is a diagrammatic perspective view of a first
embodiment of a device in accordance with the invention;
[0020] FIG. 2 is a diagrammatic perspective view of a second
embodiment of a device in accordance with the invention;
[0021] FIG. 3 is a diagrammatic perspective view of a third
embodiment of a device in accordance with the invention;
[0022] FIG. 4 is a diagrammatic perspective view showing a fourth
embodiment of a device in accordance with the invention;
[0023] FIG. 5 is a diagrammatic perspective view showing a fifth
embodiment of a device in accordance with the invention;
[0024] FIG. 6 is a diagrammatic longitudinal section view showing a
sixth embodiment of a device in accordance with the invention;
[0025] FIG. 7 is a diagrammatic longitudinal section view showing a
seventh embodiment of a device in accordance with the
invention;
[0026] FIG. 8 is a diagrammatic cross-section showing a device in
accordance with one or other of the sixth and seventh embodiments
shown respectively in FIGS. 6 and 7;
[0027] FIG. 9 is a diagrammatic cross-section view showing an
eighth embodiment of a device in accordance with the invention;
[0028] FIG. 10 is a diagrammatic perspective view showing the
internal structure of the device shown in FIG. 2;
[0029] FIG. 11 is a diagrammatic side view showing a ninth
embodiment of a device in accordance with the invention, forming an
artificial vein;
[0030] FIG. 12 is a diagrammatic cross-section view of the device
shown in FIG. 11;
[0031] FIG. 13 is a diagrammatic cross-section view showing a tenth
embodiment of a device in accordance with the invention;
[0032] FIG. 14 is a diagrammatic cross-section view showing an
eleventh embodiment of a device in accordance with the
invention;
[0033] FIG. 15 is a diagrammatic cross-section view showing a
twelfth embodiment of a device in accordance with the
invention;
[0034] FIG. 16 is a diagrammatic cross-section view showing a
thirteenth embodiment of a device in accordance with the
invention;
[0035] FIG. 17 is a diagrammatic cross-section view showing a
fourteenth embodiment of a device in accordance with the
invention;
[0036] FIG. 18 is a diagrammatic cross-section view showing a
fifteenth embodiment of a device in accordance with the
invention;
[0037] FIG. 19 is a diagrammatic cross-section view showing a
sixteenth embodiment of a device in accordance with the
invention;
[0038] FIG. 20 is a diagrammatic cross-section view showing a
seventeenth embodiment of a device in accordance with the
invention;
[0039] FIG. 21 is a diagrammatic cross-section view showing an
eighteenth embodiment of a device in accordance with the
invention;
[0040] FIG. 22 is a diagrammatic view showing the principle on
which the screen fitted to the device shown in FIG. 21
operates;
[0041] FIG. 23 is a diagrammatic view, partially in longitudinal
section, showing a nineteenth embodiment of a device in accordance
with the invention;
[0042] FIG. 24 is a diagrammatic view partially in longitudinal
section showing a twenty-first embodiment of a device in accordance
with the invention, in which the puncture zone is being pierced by
a hollow needle;
[0043] FIG. 25 is a diagrammatic cross-section view showing the
device of FIG. 24, but with the hollow needle not being shown;
and
[0044] FIG. 26 is a diagrammatic view partially in longitudinal
section showing a twenty-first embodiment of a device in accordance
with the invention.
BEST MANNER OF PERFORMING THE INVENTION
[0045] The invention relates to an implantable fluid injection
and/or extraction device 1. Such a device, which can also be
referred to as a "implantable site", is for being implanted, e.g.
surgically, in the body of a patient, and in particular under the
skin of said patient, in order to constitute an access port for
injecting and/or extracting fluids into or from the body of said
patient, which may be human or animal.
[0046] The implantable device 1 in accordance with the invention
can be implemented and adapted to a variety of uses.
[0047] Firstly, the implantable device 1 in accordance with the
invention may be designed for injecting and/or extracting fluid
into or from an organ or a vessel of the body of a patient, and in
particular in the venous and/or arterial system of said patient. In
this application, which is known in itself, the device 1 in
accordance with the invention enables medication to be injected
into a vein or an artery.
[0048] The device 1 in accordance with the invention may also be
adapted to feed implanted reservoirs, of the insulin pump or
antalgic type.
[0049] In another particular embodiment, unknown in the prior art,
the device 1 in accordance with the invention is adapted to form an
artificial vein (or artery), that a practitioner, a doctor, or a
nurse, can pierce like a natural vein for injecting medication or
taking blood.
[0050] The implantable device 1 in accordance with the invention
may also be adapted to injecting and/or extracting fluid into or
from an implantable and/or deflatable compartment of a surgical
implant, and in particular a gastroplasty ring for treating
obesity.
[0051] Such a gastric ring is itself known, and is generally formed
by a flexible strip designed to be closed in a loop around the
stomach substantially towards and at its two ends, using a closure
system in order to reduce the diameter of the aperture of the
stoma. Said strip may include an annular compression chamber of
adjustable volume connected by a catheter to an implantable device
1 in accordance with the invention, thus enabling the pressure
inside the chamber to be adjusted, so as to adjust the diametral
expansion thereof.
[0052] The device of the present invention may nevertheless be used
for adjusting other surgical implants, e.g. such as balloons or
artificial sphincters.
[0053] Below, reference is made more particularly to a hypodermic
device, i.e. a device designed to be positioned immediately under
the skin of the patient. The device in accordance with the
invention could nevertheless also be implanted at other locations
within the body of the patient, and in particular at greater
depth.
[0054] In accordance with the invention, the device 1 comprises a
housing 2 within which there is provided a chamber 2A that is
substantially hermetically closed and leaktight. The chamber 2A is
defined by a chamber wall 2B, thus defining an internal volume for
receiving a fluid to be injected and/or extracted into or from the
body of the patient. Said chamber 2A is designed to be connected to
a catheter 3, said catheter 3 itself being designed to be connected
either to an organ or vessel 10 into which it is desired to inject
fluid or from which it is desired to take fluid (cf. FIG. 11), or
else to an inflatable/deflatable compartment of a surgical implant
(not shown).
[0055] Advantageously, the housing 2 is provided with guide means
for co-operating with a guide wire to facilitate placing the device
1 under the skin of the patient. The guide means (not shown)
preferably co-operate slidably with the guide wire, the guide wire
being threaded through said guide means. In more preferable manner,
the guide means are formed by a through tunnel formed within the
housing 2, extending along the entire length thereof, e.g.
coaxially with the axis of symmetry of the housing 2. In
particular, the housing 2 may include a central tunnel for
receiving the guide wire and around which there is provided the
chamber 2A, said chamber then being annular in shape.
[0056] In accordance with the invention, the housing 2 has a
proximal wall 4 and an opposite distal wall 5, between which there
extends a side wall 6. The term "proximal", conventionally
designates the wall that is to be situated immediately under skin
of the patient, once the device has been implanted
subcutaneously.
[0057] In conventional manner, the housing 2 includes a puncture
zone 7 designed to be capable of being pierced by a hollow needle
14, in order to inject and/or extract fluid into or from the
chamber 2A.
[0058] Advantageously, the puncture zone 7 comprises a self-sealing
membrane, e.g. made of an elastomer material of the silicone type.
Such a membrane presents "self-healing" properties. By means of
these properties, the orifice generated by the membrane being
pierced by the needle 14 closes automatically after the needle 14
has been extracted, thus enabling the chamber 2A to be maintained
substantially leaktight.
[0059] In accordance with an important characteristic of the
invention, the puncture zone 7 is shaped in such a manner as to
extend simultaneously over the proximal wall 4 and the distal wall
6, i.e. so that the puncture zone 7 extends substantially around at
least part of the outlines of said proximal and side walls 4 and
6.
[0060] In other words, unlike prior art devices, in which the
puncture zone extends over a portion of the proximal wall only,
thus requiring the device 1 to be firmly sutured to the surrounding
tissues, the invention proposes a radically opposite concept,
consisting in extending the puncture zone 7 to the side wall 6 so
as to make it pointless, or at least non-essential, to secure the
device 1 by means of a suture.
[0061] In the event of the device 1 in accordance with the
invention turning over, i.e. changing its orientation, e.g. under
the effect of movements of the patient, the probability of the
puncture zone 7 being no longer accessible is reduced, given that
the puncture zone 7 extends not only over the proximal wall 4 as in
the prior art, but also over the side wall 6.
[0062] Advantageously, the puncture zone 7 is shaped so as to
extend simultaneously at least over the proximal wall 4, the side
wall 6, and the distal wall 5, so as to constitute a piercing zone
of size and shape that are sufficient to ensure that the housing 2
can be "jabbed" regardless of its angular orientation under the
skin of the patient.
[0063] In a first embodiment, shown in FIG. 1, the proximal,
distal, and side walls 4, 5, and 6 combine together to form a
surface that is substantially polyhedral.
[0064] More particularly, in the example of FIG. 1, proximal,
distal, and side walls 4, 5, and 6 form a rectangular
parallelepiped. Under such circumstances, the side wall 6 is formed
firstly by two parallel longitudinal panels 6A, 6B and secondly by
two parallel transverse panels 6C, 6D, said transverse panels 6C,
6D extending in a direction substantially perpendicular to the
direction in which the longitudinal panels 6A, 6B extend.
[0065] Advantageously, the catheter 3 is designed to be connected
to the chamber 2A through one of the transverse panels 6C, 6D via a
duct 3A connecting the chamber 2A to the outside of the device 1
and extending longitudinally substantially in the same direction as
the longitudinal panels 6A, 6B. Under such circumstances, the
catheter 3 is distinct from the duct 3A and the housing 2.
[0066] Naturally, and without thereby going beyond the ambit of the
invention, it is possible to envisage the catheter 3 being made
integrally with the duct 3A so that together they form a single
part. Under such circumstances, the housing 2 and the catheter 3
form a unit, the catheter 3 being secured to the chamber 2A by
construction and not being designed to be separated from the
housing 2.
[0067] Advantageously, the puncture zone 7 extends over the major
portion, or even substantially the totality of the proximal and
distal walls 4 and 5 and the longitudinal panels 6A, 6B. The
transverse panels 6C, 6D could naturally also constitute part of
the puncture zone 7, although that is not really necessary, given
there is little risk of the device 1 turning about the transverse
direction. Thus, all of the faces of the housing 2 shown in FIG. 1
can advantageously be used for puncturing, such that accidental
turning over of the site 1 (or a mere change of its orientation)
does not lead to genuinely troublesome consequences for the
practitioner or the patient.
[0068] The variants of FIGS. 2 to 8 are described in greater detail
below.
[0069] In the various embodiments shown in FIGS. 2 to 8, the duct
3A connecting the chamber 2A to the outside of the device 1 and for
connection to the catheter 3 extends longitudinally along a first
axis X-X'.
[0070] In order to establish a reliable mechanical connection
between the duct 3A and the catheter 3, the duct 3A may be provided
with a coaxial swelling 30A (cf. FIGS. 6 and 7) of diameter
slightly greater than the nominal inside diameter of the catheter
3. Conventionally, the catheter 3 presents a certain amount of
radial elasticity and is thus engaged by force on the duct 3A and
its swelling 30A, which serves to hold the catheter.
[0071] It is also possible to clamp the catheter 3 onto the duct 3A
by means of a clamping ring.
[0072] Advantageously, the catheter 3 is surrounded, in the
vicinity of the duct 3A, with stiffener means 20 (cf. FIGS. 1 to
5), e.g. constituted by a helical wire or tube 21 like a spring.
The stiffener means 20, which may nevertheless present a certain
amount of flexibility in bending, serve to avoid phenomena of the
catheter 3 being accidentally closed by the catheter 3 kinking.
[0073] In accordance with the embodiments of FIGS. 2 to 8, the
proximal, distal, and side walls 4, 5, and 6 are shaped and
arranged in such a manner that the housing 2 is substantially
symmetrical about a second axis Y-Y', said second axis Y-Y' being
substantially parallel to the first axis X-X'.
[0074] The housing 2 thus presents circular symmetry about a second
axis Y-Y', that extends substantially in the same direction as the
duct 3A for connection to the catheter 3. Under such circumstances,
because of the axial symmetry of the housing 2, the proximal,
distal, and side walls 4, 5, and 6 run substantially into one
another and form a single surface of revolution.
[0075] Advantageously, the proximal, distal, and side walls 4, 5,
and 6 contribute together to forming a surface that is
substantially spherical, as shown in FIG. 3. In this configuration,
the puncture zone 7 may extend substantially over all of the
proximal, distal, and side walls 4, 5, and 6, i.e. over
substantially the entire spherical surface. Nevertheless, without
thereby going beyond the ambit of the invention, provision could be
made for the puncture zone 7 to extend only over a central circular
zone of the spherical surface, said circular zone being symmetrical
about the second axis Y-Y', which preferably coincides with the
first axis X-X'.
[0076] In another embodiment, shown in FIG. 2, the proximal,
distal, and side walls 4, 5, and 6 together contribute to forming a
surface that is substantially ovoid, extending longitudinally along
the axis Y-Y' in the same direction as the duct 3A.
[0077] Such an ovoid housing turns out to be particularly easy to
insert under the skin of the patient, and is particularly well
tolerated thereby.
[0078] As with the spherical housing shown in FIG. 3, the puncture
zone 7 of the ovoid housing of FIG. 2 may extend substantially over
the entire surfaces of the proximal, distal, and side walls 4, 5,
and 6, i.e. over the entire ovoid surface. However it is also
possible, and this configuration is preferred, for it to occupy
only a central circular zone of the ovoid surface, said circular
zone being symmetrical about the second axis Y-Y'.
[0079] In the variant shown in FIG. 4, the proximal, distal, and
side walls 4, 5, and 6 together contribute to forming a surface
that is substantially pear-shaped.
[0080] Preferably, the duct 3A for connection to the catheter 3 is
connected to the chamber 2A via the tip of the pear-shaped
surface.
[0081] Advantageously, the puncture zone 7 can extend over
substantially the entire area of the proximal, distal, and side
walls 4, 5, and 6, or it may occupy merely a portion of the
pear-shaped surface, and for example, and as described for the
above variants, it may occupy only a central circular zone about
the axis of symmetry Y-Y'.
[0082] In another embodiment, shown in particular in FIGS. 5 to 8,
the proximal, distal, and side walls 4, 5, and 6 together
contribute to forming a surface that is substantially cylindrical.
The puncture zone may extend over substantially all of said
cylindrical surface, or over a portion only of said surface, and in
particular a central circular zone thereof.
[0083] Advantageously, the housing 2 corresponding to the
embodiment shown in FIG. 6 has a front ring 15 and a rear ring 16
positioned facing each other and spaced apart, being coaxial about
the first and second axes X-X' and Y-Y'. Between the rings 15, 16
there is positioned a cylindrical sleeve 17 made of elastomer
material and forming the puncture zone 7. The duct 3A is engaged in
the front ring 15, so as to be centered relative to the axis
Y-Y'.
[0084] The front and rear rings 15 and 16 may optionally be
interconnected mechanically by spacers (not shown), thus enabling
the sleeve 17 to be maintained under longitudinal compression
stress. In order to obtain this compression prestress effect, it
suffices to dimension the sleeve 17 so that its length is slightly
longer than the distance between the front and rear rings 15 and
16. The sleeve 17 is then inserted by force between the two rings,
thereby setting up compression in the elastomer material along the
axis Y-Y', which coincides in these examples with the axis
X-X'.
[0085] It is also possible, as shown in FIG. 7, to envisage that
the housing 2 includes only one distinct ring, i.e. the front ring
15, the rear ring itself being made integrally with the sleeve 17.
Provision can then advantageously be made for the region of the
sleeve 17 that corresponds to the rear ring 16 to be made of an
elastomer material that is different from that from which the
remainder of the sleeve is made, for example material that presents
greater hardness.
[0086] Advantageously, and regardless of the embodiment involved,
the housing 2 in accordance with the invention may be made up of a
frame 12 made of a material that is substantially not pierceable by
a needle 14 and that presents a certain amount of rigidity (cf.
FIG. 10). The frame 12 is advantageously covered by an envelope
(not shown) made of a self-sealing material, said frame 12 having
openings so as to form said puncture zone 7 in co-operation with
said envelope. More particularly, the frame 12 is designed to give
the housing 2 its general shape, specifically an ovoid shape for
the example shown in FIG. 10. This frame 12 serves to support an
envelope that is in the form of a substantially elastic pouch
suitable for being engaged, preferably by force, over the frame 12
and for taking up its general shape, like a sock. Advantageously,
the elastic pouch is thus stretched over the frame 12. The envelope
may advantageously comprise a membrane of elastomer material, of
the biomedical silicone type.
[0087] The frame 12 is perforated, at least locally, by a series of
orifices of sufficient size to allow the needle 14 to pass through.
After initially piercing the envelope, the needle can thus reach
the internal volume defined by the frame 12 and corresponding to
the chamber 2A.
[0088] Advantageously, the frame 12 is constituted by a lattice of
rigid material, as shown in FIG. 10. For example, the lattice may
be made of titanium wires or of stainless steel wires, or it may be
obtained by molding a plastics material.
[0089] Above, housings 2 are described that present circular
symmetry about the second axis Y-Y' that is itself parallel to or
coincides with the first axis X-X'. Nevertheless, without going
beyond the ambit of the invention, it is possible to envisage that
the housing 2 is not genuinely circularly symmetrical but is merely
formed by a curved or warped surface, e.g. of elliptical section,
as shown in FIG. 9.
[0090] Advantageously, and as shown in FIGS. 6 to 9, a screen 13
made of material that is not pierceable by the needle 14 is placed
within the chamber 2A so as to prevent the housing being pierced
right through by the needle 14. In other words, the screen 13 is
designed to prevent the tip of the needle 14, once it is located
inside the chamber 2A, from continuing its travel by piercing the
housing 2 again and thus projecting from the housing 2 into the
body of the patient.
[0091] The screen 13 acts as an abutment for the needle 14. In
particular, the screen 13 should be designed as a function of the
shape of the puncture zone 7 so as to ensure that said puncture
zone 7 can be pierced effectively and reliably at any point.
[0092] In the meaning of the invention, the term "disposed within
the chamber" when used in respect of the screen 13 should be
understood broadly. The invention relates in particular to
implantable devices provided with screens 13 that are embedded in
the structure of the housing 2 and in particular in the wall of the
chamber 2B, which is advantageously formed by the membrane forming
the puncture zone 7.
[0093] Advantageously, the screen 13 comprises a bladed wheel
shaped and positioned in such a manner that the blades 13A, 13B,
13C, and 13D extend substantially radially about the axis of
symmetry Y-Y' of the housing 2. In particular, and as shown in
FIGS. 8 and 9, said blades 13A, 13B, 13C, and 13D extend radially
from a central axis, which itself preferably coincides with the
axis of symmetry of the housing 2.
[0094] Advantageously, the blades are at least four in number and
regularly spaced apart angularly. Naturally, it is possible to
provide for the number of blades to be greater or smaller, or
indeed to provide some other type of screen 13.
[0095] The screen 13 is also preferably shaped so as to allow fluid
communication and circulation to take place within the chamber
2A.
[0096] For example, in FIGS. 8 and 9, where the screen 13 is formed
by a wheel having four plane blades 13A, 13B, 13C, and 13D, the
four compartments defined within the chamber 2A by said blades 13A,
13B, 13C, and 13D are not sealed relative to one another and are
all in fluid communication with one another, even if indirectly. To
do this, it is possible for example to ensure that the blades are
of a size that ensures they do not fit closely against the walls of
the housing 2.
[0097] The screen 13 may slope freely within the chamber 2A, or
possibly it might be held in position using a specific fastener
system. Said fastener system could, for example, comprise centering
shafts 13E, 13F (cf. FIG. 6) co-operating with complementary
recesses formed within the housing, so as to hold the bladed wheel
in position, while possibly allowing it to turn about the axis
Y-Y'.
[0098] Advantageously, the bladed wheels forming the screen 13 is
mounted to rotate within the chamber 2A. Thus, and as shown in FIG.
13, the bladed wheel preferably comprises a rotary shaft 13G
extending along the axis of symmetry of the housing 2 and of the
puncture zone 7, the shaft 13G having two curved blades 13H, 13I
extending therefrom that are diametrically opposite about the shaft
13G. Naturally, the number of curved blades 13H, 13I used could be
greater than two without thereby going beyond the ambit of the
invention.
[0099] In another embodiment, three subvariants of which are shown
in FIGS. 14 to 16, the screen 13 advantageously comprises at least
one stop panel 18A-18G for the hollow needle 14, mounted to bear
slidably against the wall of the chamber 2B so that said panel
18A-18G can be moved within the chamber 2A under the effect of
thrust exerted by the hollow needle 14 towards the inside of the
chamber 2A, during a puncture operation.
[0100] In other words, the technical principle underlying the
embodiments of FIGS. 14 to 16 lies in implementing "overall"
displacement of the screen 13 under the effect of the force exerted
by the needle 14 when it comes into abutment against the screen 13,
the displacement thereof being guided by the panels 18A-18G bearing
slidably against the wall 2B of the chamber 2A.
[0101] In the variant of FIG. 14, the screen 13 comprises two stop
panels 18A-18B, preferably presenting similar curved shapes, said
panels being disposed symmetrically in a substantially Y-shaped or
V-shaped configuration, each of the three ends of said Y-shape or
V-shape being connected to a corresponding skid 19A-19C, said skid
bearing slidably against the wall 2B of the chamber 2A. The panels
18A, 18B and their associated skids 19A-19C thus form a unit that
is guided in rotation within the chamber 2A.
[0102] The displacement of the screen 13 in the variant of FIG. 14
is thus controlled and can take place along one or more
predetermined degrees of freedom, only.
[0103] In this particular embodiment, the invention is naturally
not restricted to a screen being V-shaped or Y-shaped, and, for
example, the panels may be S-shaped (cf. panel 18C in FIG. 15) or
W-shaped (cf. panel 18D, 18E, 18F, 18G, in FIG. 16).
[0104] In the variant of FIG. 15, the screen 13 is preferably
formed by a single panel 18C having two curves to form an S-shape,
each of the ends of the S-shape being provided with a corresponding
skid 19D, 19E, that bears against the wall 2B.
[0105] In the variant of FIG. 16, the screen 13 is formed by four
plane panels 18D, 18E, 18F, 18G interconnected in a concertina
configuration to form a W-shape, with each of the vertices of the
W-shape being provided with a corresponding skid 19F-19J designed
to slide against and along the wall 2B of the chamber 2A.
[0106] Naturally, the variant of FIGS. 14 to 16 is not limited to a
particular number or shape for the panels, nor is it limited to a
particular number or shape for the skids, which skids may be
rounded in shape as in the variant of FIGS. 15 and 16, or more
spatula-shaped, as in the variant of FIG. 14.
[0107] In the variants of FIGS. 14 to 16, the panels 18A-18G are
preferably substantially rigid, and are designed so that the needle
14 naturally cannot pierce them.
[0108] In another embodiment of the invention, two subvariants of
which are shown in FIGS. 17 and 18, the screen 13 comprises at
least one stop panel 18H-180 for the hollow needle 14, preferably
disposed facing and in the vicinity of the chamber wall 2B, said at
least one panel 18H-180 being deformable under the effect of thrust
exerted by the hollow needle 14.
[0109] In other words, in this embodiment shown in FIGS. 17 and 18,
the panels constituting the screen 13 are not displaced under the
effect of the thrust exerted by the hollow needle (as applies in
the variant described above), but deforms locally under the effect
of this thrust.
[0110] In particular, as shown in FIG. 17, the screen 13 may
comprise four panels 18H-18K secured to one another so to cover the
entire surface of the wall 2B that might be pierced by the needle
14. Specifically, each panel presents in cross-section a profile
that is substantially in the form of one-fourth of a circle, such
that together the four panels present an outline that is
substantially circular, corresponding to the circular shape of the
section of the chamber 2A.
[0111] As shown in FIG. 17, under the effect of the thrust exerted
by the needle 14, the panel 18H deflects towards the inside of the
chamber 2A so as to reach a deformed configuration 18B (represented
by dashed lines in FIG. 17).
[0112] Preferably, each panel 18H-18K is deformable in bending.
Naturally, it is entirely possible, without going beyond the ambit
of the invention, to envisage that the panels 18H-180 are deformed
in some other mode, for example in compression or in traction.
[0113] It is also possible to envisage that each panel 18H-18O
comprises a plurality of substantially rigid unitary elements
interconnected by flexible links to form the panel. Under such
circumstances, the panel is not deformed because of the intrinsic
ability of the material forming the panel to deform, but by
displacing its rigid unitary elements.
[0114] Advantageously, and as shown in FIG. 18, the panels 18L-180
may present an initial shape that is curved towards the inside of
the chamber 2A.
[0115] As shown in FIG. 17, it is also entirely possible to
envisage the screen 13 being placed freely within the chamber 2A,
or on the contrary the screen 13 being secured locally to the wall
2B of said chamber 2A, as shown in FIG. 18.
[0116] When secured locally, each panel is secured to the wall 2B
of the chamber 2A via two associated lines of connection 20A-20D,
each connection line 20A-20D being common to two panels, when four
panels are used as shown in FIG. 18.
[0117] Advantageously, and as shown in FIG. 20, the screen 13
comprises a flexible membrane 21 of shape substantially matching
the shape of the wall of the chamber 2B, said membrane 21 being
placed freely within the chamber 2A and being deformable under the
effect of thrust exerted by the hollow needle 14.
[0118] In the example shown in FIG. 20, where the puncture zone 7
is substantially ovoid in shape, as shown in FIG. 2, the membrane
21 also presents a matching substantially ovoid shape, that fits
closely substantially to the shape of the wall 2B.
[0119] Advantageously, said membrane 21 can define a closed volume,
in which case it forms a flexible pouch. The membrane 21 is made of
a material that is supple and flexible, but that is strong enough
to ensure that it cannot be pierced by the needle 14.
[0120] Advantageously, the membrane 21 presents shape memory, i.e.
it is designed, after being deformed by thrust exerted by the
needle 14, to return automatically, and without external action, to
its normal configuration in which its shape substantially matches
the shape of the wall 2B.
[0121] Preferably, the needle 21 is made by weaving a material that
is substantially rigid, such as a metal or a hard plastics
material, for example.
[0122] In particularly preferred manner, the membrane 21 is
constituted by chain-mail, with the size of the links being
selected to prevent a hollow needle 14 passing therethrough.
[0123] In particularly preferred manner, and as shown in FIG. 20,
the membrane 21 floats freely within the chamber 2A, i.e. it is not
constrained to occupy a predetermined position.
[0124] Advantageously, and as naturally applies to a membrane made
of chain-mail, said membrane 21 is sufficiently porous to allow
fluid to flow throughout the chamber 2A.
[0125] Naturally, it is possible to envisage that the membrane 21
is impermeable and is secured to the wall 2B, without thereby going
beyond the ambit of the invention.
[0126] In another embodiment shown in FIG. 19, the screen 13
advantageously comprises a plurality of particulate elements 22
disposed freely within the chamber 2A, said particulate elements 22
being present in sufficient number to ensure that inserting the
hollow needle 14 into the chamber 2A causes the particulate
elements 22 to become mutually jammed against one another, at least
locally, thereby together forming a stop for the needle 14 and
preventing it from advancing.
[0127] In other words, the number of particulate elements 22 is
selected so that said particulate elements occupy substantially the
entire volume available inside the chamber 2A with the exception of
a volume fraction corresponding approximately to the volume of the
needle 14.
[0128] Thus, in the absence of the needle 14 within the chamber 2A,
each particulate element 22 can move with a certain degree of
freedom, whereas when the needle 14 is inserting into the chamber
2A, substantially all of the volume available inside the chamber 2A
is occupied, thereby having the effect of blocking the particulate
elements 22 in position relative to one another, thus preventing
any progress of the needle 14 that might lead to it passing right
through the puncture zone 7.
[0129] Advantageously, the particulate elements 22 are
substantially spherical in shape, it being understood that the
invention is not limited to a specific shape for the particulate
elements, which elements may equally well be polygonal, for
example.
[0130] Advantageously, the particulate elements 22 are made of a
material that is rigid and strong, such as a hard plastics material
or a metal.
[0131] In another embodiment, four subvariants of which are shown
in FIGS. 20 to 26, the screen 13 presents a first face 23 disposed
facing the wall of the chamber 2B and an opposite, second face 24.
Said first face 23 is provided with access means 25 allowing the
hollow needle 14 to pass through the screen 13 going from the first
face 23 towards the second face 24, so that the hollow needle 14
can pass right through the screen 13, whereas the second face 24 is
provided with blocking means 26 to prevent the needle 14 from
passing through the screen 13 going from the second face 24 towards
the first face 23.
[0132] In other words, the screen 13 of the variant embodiments
shown in FIGS. 20 to 26 can be pierced in one direction only, going
from its outside face towards its inside face.
[0133] By means of this technical measure and as shown in
particular in FIG. 22, it thus suffices to place two portions 130,
131 of screen 13 facing each other so that their respective second
faces 24 are facing each other.
[0134] In this configuration, the needle 14 can pass right through
one of the two portions 130 of the screen 13 going from its first
face 23 towards its second face 24, but will be blocked against the
second face 24 of the second portion 131 of screen 13, since said
second face 24 is provided with blocking means that prevent the
needle 14 from passing through the screen 13 going from the second
face 24 towards the first face 23.
[0135] This embodiment is thus particularly well adapted to a
puncture zone 7 extending around 360.degree. of the housing 2,
since it then suffices to line the inside wall 2B of the chamber 2A
with the screen 13 (cf. FIG. 21) so as to obtain the looked-for
"intelligent shield" effect.
[0136] The invention corresponding to the embodiment of FIGS. 20 to
26 thus relies on the screen 13 being pierced in part, said screen
13 being provided with a first face 23 that can be pierced, and
with an opposite, second face 24 that cannot be pierced.
[0137] In the variant embodiment shown in FIG. 21, the screen 13
advantageously comprises a series of unitary elements 27 disposed
side by side and urged resiliently against one another. The
elements 27 thus together form an elastically deformable sheet.
Each unitary element 27 is made of a material that is sufficiently
strong to prevent it being pierced by the needle 14. In particular,
each unitary element 27 is preferably rigid.
[0138] The unitary elements 27 co-operate to define between them in
pairs, and facing the wall of the chamber 2B, converging channels
27A for receiving the hollow needle 14, such that when the hollow
needle 14 is inserted into a converging channel 27A, as shown in
FIG. 22, that leads to the corresponding elements 27 moving apart,
thereby enabling the needle 14 to pass into the chamber 2A.
[0139] The set of converging channels 27A thus forms the first face
23 of the screen 13, i.e. the face enabling the needle 14 to be
inserted and pass in.
[0140] In the variant embodiments shown in FIGS. 21 and 22, the
element 27 also co-operate to define between one another in pairs,
opposite from the converging path 27A, an obstacle 27B preventing
the needle 14 from passing between them. The set of obstacles 27B
thus forms the second face 23, which second face 23 substantially
prevents any penetration of the needle 14 into and through the
screen 13.
[0141] Preferably, and as shown in FIG. 21, the unitary elements 27
present a cross-section of substantially triangular shape and they
are resiliently connected to one another to form a circularly
cylindrical sheet, matching the cylindrical shape of the chamber
wall 2B, the puncture zone extending continuously over said wall
2B.
[0142] Each unitary element 27 of triangular section presents, in
cross-section, a base from which two sides extend that meet at a
vertex. The triangular elements 27 are resiliently connected to one
another so that the bases of the elements 27 extend continuously
from one to another, thereby forming a surface that is
substantially smooth and uniform. This smooth and uniform surface
constitutes the second face 24, which second face 24 by its smooth
and solid nature does not allow the needle 14 to find a passage
between the triangular elements 27.
[0143] On the opposite side, the sides of the triangle extending
from the base act in pairs to define interstitial spaces of
substantially triangular shape in cross-section, each interstitial
space converging towards the inside of the chamber 2A.
[0144] When the needle 14 is inserted and pushed into one of the
interstitial spaces forming a converging path 27A, it is capable of
moving the elements 27 apart so as to open up a path to the inside
of the chamber 2A. Nevertheless, the needle 14 cannot again pierce
the membrane 7, since it is stopped on its path by the second face
24, as shown in FIG. 22.
[0145] Advantageously, the base of each triangle is of a shape that
enables the obstacle effect of the second face 24 to be
improved.
[0146] For example, as shown in FIG. 22, the base of each element
27 may include a lip 27B projecting from one of its ends, while at
its other end it presents a recess 27C of shape complementary to
that of the lip 27B, so that the triangular elements 27 can engage
mutually one in the other. Such engagement, shown in FIG. 22,
increases the reliability of the obstacle function performed by the
second face 24.
[0147] In another variant, two subvariants of which are shown
firstly in FIG. 23 and secondly in FIGS. 24 and 25, the screen 13
comprises a plurality of tubular elements 28 each of substantially
converging shape, said elements 28 preferably being substantially
identical and made of a material that cannot be pierced by the
hollow needle 14, which material is preferably substantially
rigid.
[0148] The elements 28 are engaged one in another so as to form a
substantially tubular structure presenting an outside face forming
the first face 23, and an inside face forming the second face
24.
[0149] Preferably, and as shown in FIG. 23, each element 28 is in
the form of a frustoconical ring.
[0150] In the embodiment of FIG. 23, the elements 28 are held in
position relative to one another by a link thread 29, e.g. in the
form of a flexible cord secured to each element 28.
[0151] Naturally, it is possible to envisage implementing other
means for keeping the elements 28 in position, and for example
making use of two end plates, situated at respective ends of the
stack of elements 28.
[0152] In the variant of FIG. 23, the stack of elements 28 is
disposed freely within the chamber 2A, with the dimensions of the
stack being selected relative to those of the chamber 2A in such a
manner that said stack matches substantially the inside of the
chamber 2A, and can take on only an orientation that is coaxial
with that of said chamber.
[0153] Without thereby going beyond the ambit of the invention, it
is naturally possible to envisage the tubular elements 28 being
held in position inside the chamber 2A, e.g. by being connected to
the endpiece 3A for connection to the catheter 3.
[0154] It is also possible to envisage that the membrane 7 forming
the wall of the chamber 2B is molded directly onto the stack of
tubular elements 28, or is merely secured to said stack by
adhesive.
[0155] As shown in FIG. 24, it is also possible to provide a
tubular sleeve 30 placed within the chamber 2A, coaxially
therewith, the elements 28 being engaged and held on said tubular
sleeve 30, which sleeve is preferably made of a material that can
be pierced by the hollow needle, such as silicone.
[0156] This embodiment operates as follows.
[0157] After passing through the puncture membrane 7, the needle 14
can slide into the interstitial space that exists between two
tubular elements 28, which interstitial space is encouraged by the
converging shape of each of the tubular elements. The needle 14
then passes through the sleeve 30 (if such a sleeve is provided)
and penetrates into the chamber 2A, thus enabling the desired fluid
injection or suction operation to be performed.
[0158] Assuming that the needle 14 continues its stroke, it will
come into abutment against the face 24 at an orientation that
prevents the needle from passing beyond the screen 13 and piercing
the membrane 7. The orientation of the needle 14 is controlled by
the converging orientation of the elements 28, a converging
orientation that constrains the needle to adopt an oblique path
that is substantially parallel (ignoring clearance) to the shape of
the elements 28. As can be seen in particular in FIG. 24, the
orientation of the needle 14 controlled by the first face 23
ensures that said needle 14 cannot slide into an interstitial space
between the elements 28 on reaching the second face 24 since the
interstitial spaces between the elements of the second face 24 are
at an orientation that is symmetrical to the orientation of the
needle 14 about the axis of symmetry of the chamber 2A.
[0159] Naturally, the invention is not limited to implementing
tubular elements, but extends more generally to implementing two
sloping stacks of sheets disposed symmetrically within the chamber
2A, the first stack forming the face 23 and allowing the needle 14
to pass in a predetermined oblique direction, while the second
stack blocks the travel of the needle.
[0160] In this embodiment, the invention relies on lining the
inside of the puncture zone 7 with a series of scales, said scales
allowing the needle to pass through in one predetermined direction
only.
[0161] In an alternative embodiment of the invention, as shown in
FIG. 26, the screen 13 advantageously comprises a plurality of
slats 31 disposed so as to overlap one another in part, presenting
a substantially tubular outline having an outside face that forms
the first face 23 and an inside face that forms the second face 24.
Consequently, the general technical principle underlying this
embodiment is similar, or at least very close to that implemented
by the variants of FIGS. 23 to 25, since it likewise relies on
making a system of scales, which scales are constituted by the
slats that are substantially incapable of being pierced by the
hollow needle 14. Said slats are preferably rigid, for example
being made of a metal such as steel or titanium.
[0162] In particular, each slat 31 is advantageously constituted by
a strip of metal foil.
[0163] The slats 31 are disposed so as to overlap one another in
part, so as to define, as in the variants of FIGS. 23 and 24, a
path for passing the needle 14 in a predetermined oblique
direction, which direction is incompatible with the needle
penetrating the second face 24.
[0164] Without going beyond the ambit of the invention, it is
entirely possible to envisage the screen 13 in the variants
described above and shown in FIGS. 17, 18, and 20 to 26 being
integrated completely or in part directly within the wall of the
chamber 2B. In other words, in this configuration, the elements
forming the screen 13 are advantageously embedded in the structure
of the wall 2B, which is preferably formed directly by the "septum"
membrane forming the puncture zone 7. This technical measure can be
used in particular for maintaining the screen-forming elements 13
in position relative to one another without using any additional
means such as the thread 29 or the sleeve 30 being necessary.
Preferably, when the elements forming the screen 13 are embedded in
the puncture membrane, said elements are embedded at a distance
from the surface of the wall 2B that is small enough to ensure that
when the hollow needle 14 is in abutment against the screen 13, its
orifice, which conventionally opens out in a chamfer at the tip of
the needle, is not closed and opens out into the chamber 2A.
[0165] Naturally, the use of a screen 13 is purely optional.
[0166] There follows a description in greater detail of the
embodiment shown in FIGS. 11 and 12 which relates to a hypodermic
device 1 for injecting medication into a vein 11 (or an artery)
and/or for taking blood from said vein 11 (or artery), said device
1 thus forming an artificial vein or artery.
[0167] The device 1 in accordance with this embodiment seeks to
imitate a natural vein in realistic manner so as to take the place
thereof for operations of injecting medication intravenously or
operations of taking blood.
[0168] For this purpose, the device 1 substantially reproduces the
shape of a portion of a natural vein, i.e. it is in the form of an
elongate tubular housing, e.g. made entirely out of a pierceable
material, of the silicone type.
[0169] The device 1 as made in this way is for lying flush under
the skin of the patient, above the vein 11 to which it is
connected.
[0170] The device 1 in accordance with this embodiment is for being
pierced in the same manner as a natural vein, i.e. at a grazing
angle relative to the patient's skin, and not perpendicularly as
when piercing a prior art site. Such "tangential" piercing means
that the presence of the screen 13 is not absolutely necessary.
[0171] Nevertheless, such a screen can be envisaged, as is shown in
the variants of FIGS. 11 and 12.
[0172] In this variant, the distal wall 5 is substantially plane
and is defined laterally by two side edges 5A, 5B, while the
proximal wall 4 and the side wall 6 contributes together to forming
a surface of revolution, e.g. semicircular, interconnecting said
side edges 5A, 5B.
[0173] The screen 13 constitutes a gutter, made of a material that
cannot be pierced by the needle 14, but that is preferably
flexible. Said gutter advantageously presents a channel section,
with the web on the channel section resting in the chamber 2A on
the distal wall 5, while the flanges of the channel section are
upstanding against the side wall 6.
[0174] The concept of an artificial vein developed in the ambit of
the present invention presents a character that is quite
independent of the other applications mentioned above.
[0175] Finally, it should be observed that the housing 2 may
advantageously be radio-opaque, by including an appropriate marker
substance in its internal structure, either uniformly or
otherwise.
SUSCEPTIBILITY OF INDUSTRIAL APPLICATION
[0176] The invention finds its application in making and using
implantable sites for injecting and/or extracting fluid.
* * * * *