Note: Descriptions are shown in the official language in which they were submitted.
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WO 01/83023 PCT/CHOl/00499
Percutaneous or transcutaneous access to the interior
of the body
The present invention relates to a percutaneous or
transcutaneous connection system according to the
preamble of claim 1, to uses of the system, and to a
method according to the preamble of claim 12.
A wide variety of accesses to the interior of the human
body are known from the literature and from patents.
Artificial accesses of these kinds are needed, for
example, for administering medicines or delivering
electrical signals or electrical energy into the body.
There is a fundamental difference between percutaneous
and transcutaneous accesses. Percutaneous accesses
extend mechanically through the skin. Transcutaneous
accesses do not actually involve any mechanical access.
They are often based on the induction principle and
thus represent an electrical connection between the
interior of the body and its external environment.
In designing such accesses, it is not just the
functional connection itself that is important, but in
particular also the assimilation at the site of
implantation and the minimizing of the risk of
infection. In addition, it must be possible for the
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patients, or at any rate for their medical care
providers, to make or break the connection as quickly
and as easily as possible (user friendliness).
W098/51367 and W099/34754 propose purely mechanical
plug-type connections for coupling and uncoupling the
access. Since a minimal contact pressure is required at
the connection site both for electrical leads and for
administration of fluids, the constructions turn out to
be relatively complicated, and the coupling and
uncoupling operations are awkward for the user. In
contrast, US 5,507,303 proposes, inter alia, that the
necessary contact pressure be generated by
magnetostatic means. In this case, both the implanted
part and the attachable part each contain a magnet,
these magnets ensuring the contact pressure. However,
the external part is guided and oriented relative to
the implanted part of the access by mechanical means.
US 5,949,895 discloses a transcutaneous connection
consisting of a pair of flat, -symmetrical coils which
are oriented with respect to one another with a pair of
cylindrically symmetrical permanent magnets. This
latter configuration, too, is relatively complicated
and not user-friendly.
It is therefore an object of the present invention to
provide a percutaneous or transcutaneous connection to
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the body of a living thing, in particular of a human,
which connection does not have the aforementioned
disadvantages.
The object of the invention is achieved by means of a
connection system according to the wording of claim 1.
The percutaneous or transcutaneous accesses to the
interior of the body, as proposed according to the
invention, utilize magnetostatic forces both for
ensuring the necessary contact pressure and for
orienting and positioning the external part of the
access relative to the implanted part. This results in
a connection which is much easier for the user to
handle. Positioning can be made easier by using
permanent magnets which are asymmetrical, for example
elongate. The north and south poles of the magnets are
not mutually aligned inward toward the interior of the
body as in US 5,507,303, but instead along the body
opening. In other words, the permanent magnet extends
with its poles parallel to the skin of the body.
Advantages are afforded in particular if the connection
between the interior of the body and the external
environment of the body has an inherent asymmetry. This
is the case, for example, when the number of the
individual passages in a percutaneous connection cannot
be arranged symmetrically. Such a case likewise arises
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when two asymmetrical flat coils of a transcutaneous
connection are to be oriented relative to each other.
The invention is now explained in greater detail below
by way of example and with reference to the attached
figures, where:
Figure 1 shows, in longitudinal section, a percutaneous
connection with two individual passages:
Figure 2 shows the plan view of the magnets illustrated
in Figure 1; and
Figure 3 shows a diagrammatic representation of a
transcutaneous connection with two flat,
physiologically shaped coils in the region of the outer
ear.
Figure 1 is a longitudinal section showing a two-part
percutaneous connection with two individual passages.
One part 5 is formed by a permanent magnet 7 which is
located underneath the epidermis 1 in. the area of the
dermis or in the area of a bone 3 lying underneath the
epidermis. The north pole and the south pole of the
permanent magnet 7 are labeled N and S, respectively.
Extending through the permanent magnet are two passages
9, each of these having a widened opening 11 protruding
slightly from the epidermis 1. This is of course only
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one example of the design of the passages, and instead
it is also possible to provide just one passage or
multiple passages, and these passages do not
necessarily need to have an external enlarged opening
11.
The internal openings of the passages open into an area
labeled 8, which is provided for the arrangement of
delivery and withdrawal conduits.
As a mating piece for this, an external attachable part
15 is provided which for its part has a permanent
magnet 17 with a south pole and a north pole, labeled S
and N, respectively. Extending from a delivery or
withdrawal conduit 19, which for example can be a
flexible tubing, and through the permanent magnet 17
there are two conduits or two accesses 21 which for
their part each have a connection opening 23 facing
toward the openings 11 and may be suitable, for
example, for attaching the external part 15 onto the
two openings 11. If the force. of the two permanent
magnets is not sufficient to hold the external part 15
on the permanent magnet 7, catch elements or other
retaining members, for example, may additionally be
provided.
The conduits in the implanted part 5 and also in the
external plug-in part 15 are suitable both for
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delivering substances such as medicines, nutrients and
the like, and also for withdrawing fluids from inside
the body. The latter is the case, for example, in what
is called hemodialysis.
Figure 2 on the one hand shows the permanent magnet 7
in a plan view from the outside, the omission of the
depiction of the epidermis 1 meaning that the permanent
magnet is visible, as is also the dermis or bone 3
located underneath the epidermis. Clearly shown are the
two passages 9 extending perpendicularly through the
permanent magnet 7. The elongate, oval-shaped permanent
magnet in Figure 2 can of course be differently
configured, for example rectangular, rod-shaped etc.
Analogously thereto, Figure 2 also shows, again in a
plan view, the external plug-in part 15 consisting
primarily of the permanent magnet 17 and of the
accesses and conduits 21 provided for plug-in
connection to the passages 9. Of course, the external
magnet 17 also does not have to be in the form of an
elongate oval, and instead can be differently
configured, in adaptation to the shape of the permanent
magnet 7. Indeed, it is even possible to arrange a coil
in the external part 15 for generating a magnetic
field, since the external magnet 17 does not
necessarily have to be a permanent magnet.
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Finally, Figure 3 shows a possible application of the
system proposed according to the invention in the form
of a transcutaneous connection with two flat,
physiologically shaped coils in the region of a human
ear 31.
Given the anatomical and physiological conditions in
this region, an arrangement of circular coils, as are
otherwise often used in transcutaneous connections, is
not suitable here. Instead, from this point of view a
pair of oval, kidney-shaped or otherwise asymmetrically
shaped coils is to be preferred.
The implanted part 25 of a transcutaneous connection
has a coil 27 which serves to receive or, respectively,
send electrical signals and/or to transmit electrical
energy. The implanted part 25 also has a permanent
magnet 29 which serves to orient and fix an external
part in relation to the implanted part. This fixing may
be necessary in particular when a current does not flow
through the coils. Both the coil 27 and the permanent
magnet 29 are implanted underneath the skin and are not
visible from the outside. Therefore, in contrast to
percutaneous connections, there is no mechanical
passage here from the interior of the body to the
outside or from the outside of the living thing to the
inside. This system is shown in Figure 3, with the
epidermis above the implanted part having been omitted
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so as to make the implant visible.
The external part (not shown here) of the
transcutaneous connection likewise has, on the one
hand, a coil for transmitting signals and/or energy
and, on the other hand, a permanent magnet for
positioning and fixing. The area of the external part
of the connection directed toward the implanted part
comprises materials and a surface which are compatible
with the skin and permit wearing comfort. In terms of
their geometric shape and their magnetic strength, the
pair of permanent magnets is configured in such a way
that the external part of the connection is optimally
aligned and positioned over the implanted part as soon
as it is brought into the proximity of the implant. The
orientation is optimal when the inductive coupling
between the coils, in their geometric shape dictated by
the anatomy, is at a maximum level. The positioning and
retaining action of the permanent magnets is effective
in this transcutaneous system too, because the
magnetostatic field also acts through the skin.
Of course, the connections depicted in Figures 1-3
merely represent possible examples, and the present
invention is not limited to the illustrative
embodiments shown. It follows that great variations are
conceivable in terms of the design of the permanent
magnet, the arrangement of the permanent magnet
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directly in the epidermis or underneath the epidermis
or in the bone, etc., the use of one, two or more
passages, or of inductive, capacitive or other passage-
free connections etc., or the configuration of the
external plug-in part, etc.
