Orthogonal sensing for use in clinical electrophysiology

• US 5,385,146 A
• Filed: 01/08/1993
• Issued: 01/31/1995
• Est. Priority Date: 01/08/1993
• Status: Expired due to Term

• Current Assignee: New Chester Insurance Company Limited
• Original Assignee: Bruce N. Goldreyer
• Inventors: Goldreyer, Bruce N.
• Primary Examiner(s): Sykes, Angela D.
• Application Number:
  US08/001,980
• Time in Patent Office: 753 Days
• Field of Search: 128/639, 128/642, 128/783-784, 128/785-786, 607/115, 607/116, 607/119, 607/122-124, 607/154, 606/13, 606/33, 606/27-31
• US Class Current: 600/374
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2018/0016 Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/1253 monopolar
• CPC Class Codes: A61B 2018/126 bipolar
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/339 Displays specially adapted therefor
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/06 for high-frequency therapy
• CPC Class Codes: A61N 1/403 for thermotherapy, e.g. hyperthermia

Abstract

Accurate mapping of electrophysiologic activation within the human heart is achieved for discrete areas within the heart by utilizing a catheter having at least one pair of orthogonal sensors disposed on the catheter. Orthogonal sensors, which are comprised of two or more electrodes generally disposed circumferentially on the catheter at given longitudinal position along the catheter, receive signals which are differenced within a differential amplifier to produce a signal indicative only of the localized or near field biopotential heart activity. The orthogonal sensors are disposed adjacent to the stimulating tip of the catheter to allow sensing of the localized cardiac activity which is adjacent to or in contact with the stimulating tip during pacing procedures or during the delivery of radio frequency energy during ablation. Sensing of the localized cardiac activity occurs simultaneously either with the pacing or the ablation so that detailed and accurate electrocardiograms of the stimulated or ablated tissue region can be recorded. A plurality of such a orthogonal sensors longitudinally disposed along the body of the catheter with spacings between each of them of 1-3 millimeters allows for simultaneous mapping of localized cardiac activation at a corresponding plurality of positions within the heart wall even when physical contact between the sensing electrodes and heart wall does not or cannot occur.

Claims

1. A method for mapping electrophysiologic activation in a heart notwithstanding the presence of high intensity swamping signals for other purposes comprising the steps of:

disposing a catheter within said heart at a predetermined position;

sensing only localized cardiac signals from myocardium within 1 to 3 millimeters from said predetermined position by sensing said cardiac signals on at least a pair orthogonal electrodes disposed on said catheter within 1 to 3 millimeters of a position on said catheter near said predetermined position in said heart while said swamping signals are introduced into said heart; and

repeating said steps of disposing and sensing only said localized cardiac signals from a plurality of different predetermined positions within said heart while said swamping signals are introduced into said heart, so that accurate and discrete mapping of electrophysiologic activation within said heart is achieved,

wherein said step of sensing said cardiac signals on said orthogonal electrodes comprises the step of differencing cardiac signals received on each of said orthogonal electrodes to generate a differential signal therebetween, said differential signal being indicative of said localized cardiac activity.

2. A method for mapping electrophysiologic activation in a heart notwithstanding introduction of high intensity swamping signals for other purposes comprising the steps of:

disposing a catheter within said heart;

sensing only localized cardiac signals from myocardium within 1 to 3 millimeters from each of a plurality of positions on said catheter by a corresponding plurality of pairs of orthogonal sensing electrodes longitudinally disposed along the length of said catheter at said plurality of positions while said swamping signals are introduced into said heart; and

repeating said steps of disposing and sensing only said localized cardiac signals from a plurality of different predetermined positions within said heart, so that accurate and discrete mapping of electrophysiologic activation within said heart is achieved even though said swamping signals are being simultaneously introduced into said heart,

wherein said step of sensing along said plurality of positions longitudinally disposed on said catheter is performed at a corresponding plurality of orthogonal electrodes, said cardiac signal received by each of said plurality of orthogonal electrodes being differenced to produce a corresponding plurality of differential signals indicative of localized signals at each of said corresponding positions along said catheter.

3. A catheter for mapping electrophysiologic activity within a heart notwithstanding the presence of high intensity swamping signals for other purposes comprising:

a catheter body for disposition within said heart, said catheter body having a distal tip;

at least one pair of orthogonal electrodes disposed on said catheter body at a predetermined position;

means for receiving and differencing cardiac signals received by said at least one pair of orthogonal electrodes to generate a difference signal indicative of localized cardiac activity only at myocardium within 1 to 3 millimeters of said predetermined position of said orthogonal electrodes on said catheter; and

a catheter tip electrode disposed on said distal tip of said catheter for introducing said swamping signal into said heart, said catheter tip electrode arranged and adapted for delivery of a stimulating pulse to a selected position in said myocardium for pacing said heart while simultaneously sensing said localized cardiac activity through said orthogonal electrodes at said predetermined position within 1 to 3 millimeters of said myocardium being stimulated for pacing at said selected position,

whereby a catheter is provided for discretely and accurately mapping electrophysiologic activity within said heart.

4. The catheter of claim 3 wherein said orthogonal electrodes are disposed adjacent to said stimulating catheter tip electrode and simultaneously sense electrophysiologic activity in response to a pacing stimulus.

5. A catheter for mapping electrophysiologic activity within a heart notwithstanding the presence of high intensity swamping signals for other purposes comprising:

a catheter body for disposition within said heart, said catheter body having a distal tip;

at least one pair of orthogonal electrodes disposed on said catheter body at a predetermined position;

means for receiving and differencing cardiac signals received by said at least one pair of orthogonal electrodes to generate a difference signal indicative of localized cardiac activity only at myocardium within 1 to 3 millimeters of said predetermined position of said orthogonal electrodes on said catheter; and

an ablative electrode disposed on said catheter for introducing said swamping signals into said heart by applying radio frequency energy through said ablative electrode to extirpate myocardium in contact with said ablative electrode,

whereby a catheter is provided for discretely and accurately mapping and ablating electrophysiologic activity within said heart.

6. The catheter of claim 5 wherein said orthogonal electrodes are disposed within 1 to 3 millimeters of said ablative electrode for simultaneously sensing electrophysiologic activation of myocardium subject to extirpation while ablative energy is being applied to said myocardium.

7. A catheter for pacing a heart comprising:

a catheter body for disposition within said heart;

at least one pair of orthogonal electrodes disposed on said catheter body at a predetermined position for sensing localized cardiac activity only from myocardium within 1 to 3 millimeters of said predetermined position; and

means for receiving and differencing cardiac signals received by said at least one pair of orthogonal electrodes to generate a difference signal indicative of localized cardiac activity only at myocardium within 1 to 3 millimeters of said predetermined position of said orthogonal electrodes on said catheter body, said means for receiving and differencing cardiac signals coupled to said at least one pair of orthogonal electrodes;

a catheter tip electrode disposed on said distal tip of said catheter, said catheter tip electrode being arranged and adapted for delivery of a stimulating pulse for pacing said heart; and

wherein said orthogonal electrodes and means for receiving and differencing cardiac signals are arranged and adapted for simultaneously sensing said localized cardiac activity during delivery of said stimulating pulse to said catheter tip electrode,

whereby said catheter is provided for stimulating said heart in response to localized cardiac signals from myocardium immediately adjacent to said orthogonal electrodes.

8. A catheter for ablation in a heart comprising:

a catheter body for disposition within said heart;

at least one pair of orthogonal electrodes disposed on said catheter body at a predetermined position for sensing localized cardiac activity only from myocardium within 1 to 3 millimeters of said predetermined position;

means for receiving and differencing cardiac signals received by said at least one pair of orthogonal electrodes to generate a difference signal indicative of localized cardiac activity only at myocardium within 1 to 3 millimeters of said predetermined position of said orthogonal electrodes on said catheter body, said means for receiving and differencing cardiac signals coupled to said at least one pair of orthogonal electrodes; and

an ablative electrode disposed on said catheter arranged and adapted for applying energy through said ablative electrode to extirpate myocardium in contact with said ablative electrode; and

wherein said orthogonal electrodes are disposed adjacent to said ablative electrode, said orthogonal electrodes and means for receiving and differencing cardiac signals being arranged and adapted for simultaneously sensing said localized cardiac activity of myocardium subject to extirpation while ablative energy is being applied to said myocardium through said ablative electrode, where by said catheter is provided for ablating selected myocardium in said heart in response to localized cardiac signals from myocardium immediately adjacent to said ablative electrode.