The invention concerns a multipolar electrode arrangement having a plurality of electrodes with an electrical feed line.
A particular area of use of multipolar electrode arrangements is the output of electrical signals to body tissue, in particular cardiac tissue, and picking up electrical signals from the heart. Contraction and relaxation of the cardiac muscles is controlled by electrical signals which pass through the cardiac tissue in an excitation front. Knowledge about signal propagation in the heart is an aspect of great significance, in terms of diagnosis and therapy of heart diseases. U.S. Pat. No. 5,921,923, to Kuck (Jul. 13, 1999), discloses a multipolar electrode arrangement in which the electrodes are arranged in such a way that not only the occurrence of events but in addition also the direction and speed of stimulus conduction can be detected.
For that purpose the poles are spatially arranged in relation to each other on the catheter in such a fashion that respective pairs thereof so-to-speak define a co-ordinate system. Other electrode arrangements are to be found in U.S. Pat. No. 5,385,146 to Goldreyer (Jan. 31, 1995) and U.S. Pat. No. 5,476,503 to Yang (Dec. 19, 1995).
That object is attained by an electrode arrangement of the kind set forth in the opening part of this specification, in which the electrodes are connected to an electrode carrier which is adapted to be insertable together with the electrodes into the lumen of a catheter.
An electrode arrangement of that kind permits simplified manufacture of any pole configurations in particular on a single lead electrophysiology catheter. In that respect the configuration of the electrodes is predetermined by the electrode carrier. The electrode carrier with the electrodes secured thereto can be pre-assembled and then inserted with electrical feed lines into a catheter tube.
A preferred electrode arrangement is one in which the electrode carrier is elastically deformable, more particularly preferably substantially in a first plane while it is substantially stiffer in a second plane which is perpendicular to the first plane. For that purpose the electrode carrier preferably includes a leaf spring element of preferably flat cross-sectional profile.
The leaf spring element is preferably of an electrically insulating nature and is preferably of a flat cross-sectional profile. In a preferred embodiment the electrode carrier and in particular the leaf spring element at least partially comprise a polymer. The electrode carrier can then be in the form of an injection molding in a particularly desirable fashion.
The advantages of an electrode arrangement with such an electrode carrier are pertinent in particular when the electrode carrier is connected at its distal end to a control means which is guided longitudinally slidably along the electrode carrier relative thereto so that deflection of the electrode carrier can be effected at the distal end thereof by longitudinal displacement of the control means relative to the electrode carrier. It is possible in that way to provide an electrophysiology catheter which can be targetedly and specifically deflected in cavities such as for example the atrium or ventricle of a heart and guided into a defined direction in order to be able to pick up signals at defined locations in the heart. For that purpose the catheter tip can be provided with marking means which make it possible to locate the catheter tip from outside the body by means of imaging processes.
Preferably, the electrode arrangement includes a catheter having a lumen which is adapted to receive the electrode carrier, wherein the catheter has openings which extend from the lumen and which are of such an arrangement and configuration that the electrodes connected to the electrode carrier can pick up electrical signals outside the catheter. In a preferred alternative configuration, the openings can be disposed in the peripheral surface of the catheter and in particular of a catheter tube, more specifically in such a way that a corresponding opening is provided for each individual electrode. Alternatively however the electrode carrier can also be designed in such a way that as a whole it projects out of a central opening at the distal end of the catheter or catheter tube.
A further preferred electrode arrangement is one in which the electrodes are arranged in mutually displaced relationship in the longitudinal and peripheral directions of the catheter in such a way as to afford at least one electrode matrix which makes it possible to determine the direction and speed of a signal from the time displacement with which the signal reaches various ones of the electrodes. In that respect, an adequate spacing not only in respect of the center points of the surfaces of the individual electrodes but between the electrode surfaces is advantageous in terms of determining the speed of the stimulus conduction.
In the above-mentioned electrode arrangement an electrode matrix preferably includes at least three electrodes, wherein the center points of the surfaces of the electrodes of an electrode matrix are preferably arranged at the corners of notional triangles or quadrangles.
As an alternative to the electrodes being made from metal, which affords the advantage of the high level of conductivity of metal, a particularly preferred electrode arrangement is one in which the electrodes include conductive plastic material.
In an advantageous embodiment, such an electrode arrangement makes it possible to arrange the electrodes in depressions in a non-conductive base material, in particular the insulating leaf spring element. The depressions can be produced for example with a high degree of precision by means of a laser beam so that even small microstructures can be produced. The non-conductive base material can be a component part of the electrode carrier.
In principle electrodes of conductive plastic material are known from U.S. Pat. specifications Nos. 5,433,742 and 5,029,585.