Electrophysiology catheter
The invention relates to electrophysiology catheter systems and their use, such as in an MRI environment, and in particular to analysis of electric signals from such. An electrophysiology (EP) catheter with a plurality of electrically isolated electrode segments arranged in longitudinally spaced bands around the catheter is used to detect electric signals. A workstation receives the electrical signals which are then processed by a processing unit. Electric signals from electrode segments can be used to determine roll angle information of the catheter in relation to patient anatomy by determining signals from electrode segments in contact with tissue. Also, electric signals can be used to extract a reference signal that can be used to correct for gradient induced artifacts.
1. An electrophysiology catheter system comprising:
an electrophysiology catheter with an elongated distal end portion having a centre axis and being bendable in at least one direction transverse to the centre axis, comprising:
two or more longitudinally spaced bands around said end portion, each band comprising a plurality of electrically isolated electrode segments for detecting electrical signals and being arranged in a band around said end portion;
a plurality of electrode wires each coupled to an electrode segment and extending through the distal end portion to a proximal end portion of the electrophysiology catheter; and
a workstation arranged to receive electrical signals detected by each electrode segment by means of the electrode wires coupled thereto and comprising a processing unit configured to identify electrode segments that are in contact with tissue from the received electrical signals by comparison of the electrical signal from each electrode segment with that from one or more other electrode segments or a predetermined threshold value and presenting the identified electrode segments to an operator with an indication of the identified electrode segments' position in relation to a bending direction or another marker of roll angle of the distal end portion.
2. The electrophysiology catheter system according to claim 1 , wherein the workstation further comprises a four wire impedance measuring setup for measuring an impedance between first and second electrode segments, wherein the comparison of the processing unit comprises calculating an impedance between the first and second electrode segments from the detected electrical signals from the first and second electrode segments.
3. The electrophysiology catheter system according to claim 1 , wherein the workstation comprises a graphical user interface for presenting the positions of electrode segments identified to be in contact with tissue in relation to a bending direction or another marker of roll angle of the distal end portion.
4. A computer program product embodying computer instructions on a non-transitory computer readable medium, for identifying electrode segments that are in contact with tissue, the product comprising software applications which provides the following when executed by a processor in a processing unit of an electrophysiology catheter system comprising an electrophysiology catheter with an elongated distal end portion having a centre axis and being bendable in at least one direction transverse to the centre axis and comprising a plurality of electrically isolated electrode segments for detecting electrical signals and being arranged in two or more longitudinally spaced bands around said end portion:
identifying electrode segments that are in contact with tissue from the received electrical signals by comparing electrical signal from each electrode segment with that from one or more other electrode segments or a predetermined threshold value; and
presenting the identified electrode segments to an operator with an indication of the identified electrode segments' position in relation to a bending direction or another marker of roll angle of the distal end portion.
5. A method for analysing electric signals from an electrophysiological catheter with an elongated distal end portion having a centre axis and being bendable in at least one direction transverse to the centre axis and comprising a plurality of electrically isolated electrode segments for detecting electrical signals and being arranged in two or more longitudinally spaced bands around said end portion to obtain information of which, if any, electrode segments in contact with tissue, the method comprising: comparing electrical signal from each electrode segment with that from one or more other electrode segments or a predetermined threshold value; and as an outcome of the comparison, identifying electrode segments that are in contact with tissue; presenting the identified electrode segments to an operator with an indication of the identified electrode segments' position in relation to a bending direction or another marker of roll angle of the distal end portion.