ELECTRODE SERVANT A DISSOUDRE LES CALCULS RENAUX

ELECTRODE TO DESTROY RENAL STONES

Abrégé anglais

ABSTRACT
This invention is related to the field of medicine, and,
specifically to apparatus for the destruction of renal stones. The
disclosed electrode can be used several times in patient therapy,
based on the fact that its main components are interchangeable. It
consists of a core (1), a threaded aperture (2) where a support rod
(3) is introduced with a conical tip (4) having a cylindrical step
for its retention. A cage (5) of four elements with a central
aperture (6) supports another conical tip (7).

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An electrode with interchangeable parts comprising a
core (1) having a threaded aperture (2) adapted to receive a support
rod (3) having a conical tip (4), the support rod having a
cylindrical step for the reception of the tip, a cage (5) of four
elements with a central aperture (6) receiving a further tip (7) of
conical configuration.

Description

`~ 1328125
Thie invention i9 related to the field of Medicine. I-t
relate~ to apparatu3 for the creation of ~hock wave~ to destroy renal
~tone~.
Different types of electrodee to de~troy renal ~tone~ are
already known; ~ee, for example, German Patent # 35 43 881
International Cla~ification A61B 17/22) which consi~t~ of an
electrode that ha~ a core with a rigid qharp end, a ~ocket with a
central aperture having in its thin wall aix perimetral aperture~
parallel to the central on0. A cage i~ provided a~ an additional
component. The technical di~advantages of this electrode i~ tha-t it~
tip~ are not removable and interchaneeable ~o that the electrode can
be u~ed only once.
Another technical di~advantage i~ related to the
eocket-cage a~sembly where the ~ix perimetral aperture~ and the ~ix
elements fixed by the welding to the socket do not ~upply sufficient
rigidity to the unit ~o that the tips are easily di~placed during
operation, which reduce~ electrode efficiency. The con~tructed unit
iq extremely complex technically.
Another electrode i~ ~hown in German Patent 331~837 which
coneiqtc of a cage formed by three element~ ~upporting a mandrel,
with a tip placed in a cyllndric bar structure, removable and
adju~table. The core end~ in a mandrel which hold~ the tip.
The technical disadvantage of thi~ electrode i9 that the
cage ha~ three element~ distributed at 120 radially which pre~ent a
barrier to the exit of the ~hock wave. Ideally there ~hould not be
any element in the cage aligned with the longer ~emi-axiq of the
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semi-ellipse, but thi~ is unavoidable in this construction leading to
the destruction of one of the elements by cavitation. The mandrel
portion of the cage results in an increase in the stresses of the
supported elements, decreasing the electrode's useful life and
reliability. From a technical view point its manufacture is as
complex as the unit of the previous patent. It has a significant
loss of energy of the shock wave because the end or apex where the
energy is produced is of plane shape.
The es~ence of the present invention consists of an
electrode that has a core with a threaded aperture where a ~upport
rod is introduced with an interchangeable tip of conical shape having
a cylindrical step for its retention and a cage having four element~
around a central aperture where another tip of conical shape is
introduced also with a cylindrical step for its retention.
~rief Description of the Drawing
-
Fig. 1 i~ a main view of the electrode in cross-section
showing the core and cage.
Figure 2 i~ an illustrative view of the cage and it~ cross-
section along line A-A.
The invention consi~ts of an electrode (Fig. 1) with a core
(1) and a threaded aperture (2) receiving a support rod (3) with a
conical tip (4) having a cylindrical step for its retention which may
be welded in position. A cage (5) is provided having four elements
with a central aperture (6) receiving a conical tip (7) retained by a
cylindrical step.
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The manufacture of this electrode is a3 follows: The
support rod is tapped to form a hole (3) where the tip i~ in~erted
and rigidly fixed (4), this unit is fixed in position with a set
screw (2) that also enablee adjustment of the support rod ~3) in the
core (l). An insulator (8) receives the core and holds it and the
~upport rod securely, The insulator (8) is formed externally to be a
~upport for ths cage (5), which i9 generally cylindrical and supports
the tip (7).
The advantage of this electrode is based on the fact that
it~ manufacture enables interchangeability of tips (7 and 4). The
de~ign i~ straightforward since the cage (5) and external tip (7)
make up a unit of two sections and not eight a~ in Patent # 35 43 881
and the electrode patent ~ 3316837 which ha~ a mandrel rigidly fixed
to the cage besides being welded in three places to the rest of the
unit.
Another characteristic i~ that the welding of cage (5) to
tip (7) iY performed around a single aperture which differs from the
identified patent3 which require many welds.
Another characteri~tic of the electrode of this invention
is that the support rod (3) enables adjustment and change of the tip
(4).
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