US20030109778A1 - Electrophysiology/ablation catheter and remote actuator therefor - Google Patents

Abstract

A cardiac catheter employed for minimally invasive cardiac diagnostic electrophysiology and/or cardiac ablation procedures. The catheter of this invention comprises of an elongated cylindrical and electrically non conductive main exterior tube with plurality of surface electrodes disposed on its distal portion, and a handle on its proximal end. The distal portion of this catheter can be curved and the assumed curvature can be retained by a single action on manual actuator of the catheter handle. In one embodiment of this invention an electromechanical drive system is incorporated into the catheter handle for formation of curvatures at the distal portion of the catheter. In a further embodiment an electrical heating element is incorporated within the distal electrode of the catheter for ablation procedures. In another embodiment of this invention a readily removable and disposable blood contacting segment is provided. The non-blood contacting actuator is thus reusable and reduces the cost of the cardiac electrophysiology and/or ablation procedure. The catheter of this invention comprises two tension/compression members for curvature formation at the distal end of the catheter. These tension/compression or pull/push members are wires with circular cross-sections that are integrally formed into ribbon-like configurations at their distal portions for enhanced deflectability. The actuator handle includes a pivoted member movable in one direction by the thumb of the user's hand grasping the handle and in the opposite direction by the other fingers of the same hand.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a Continuation-In-Part of my co-pending application Ser. No. 08/880,080 filed Jun. 20, 1997 entitled:“Electrophysiology Catheter and Remote Actuator Therefor.”[0001]
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
• Not Applicable[0002]
MICROFICHE APPENDIX
• Not Applicable[0003]
BACKGROUND OF THE INVENTION
• a) Field of the Invention[0004]
• The present invention relates to a catheter employed for diagnostic and/or therapeutic procedures in medicine, more specifically in minimally invasive cardiac electrophysiology studies and/or cardiac ablation procedures.[0005]
• b) Description of the Prior Art[0006]
• The primary device for an intra-cardiac electrophysiology study is a catheter with conductive electrodes at its distal portion [U.S. Pat. Nos. 5,156,151, 5,279,299, 5,415,633, 5,454,370, 5,465,717]. The distal portion of the catheter, where the electrodes are located, is commonly placed transvenously into the heart to monitor and/or record the intra-cardiac electrical signals during electrophysiology studies, or during intra-cardiac mapping. The function of these electrodes on the catheter is to conduct cardiac electrical signals to appropriate monitoring and recording devices.[0007]
• During the diagnostic procedures, the catheter is also used as a medium to deliver low energy electrical pulses from a cardiac stimulator to the heart in order to evaluate the heart's response to the cardiac stimulator signals.[0008]
• During therapeutic (cardiac ablation) procedures, electrical energy in the form of radio-frequency, microwave or high-voltage pulses is delivered from an appropriate energy source to the heart commonly via the catheter's distal electrode. The intent of this energy delivery is to destroy the site of the cardiac tissue that causes abnormality (arrhythmia) to the normal rhythm of the heart.[0009]
• During such a minimally invasive cardiac ablation procedure the distal portion of a catheter, which usually comprises a plurality of spaced annular cylindrical electrodes and a distal electrode, is transvenously placed into the heart. The proximal end of the catheter, remote from the electrodes, has electrical leads which are connected to an appropriate recording and/or monitoring device. The intra-cardiac electrical signals can then be monitored and recorded.[0010]
• A surface electrocardiogram, obtained from patient's skin, is concurrently compared with the intra-cardiac electrical signals. Typically, when a known catheter is employed for ablation procedures, an electrically conductive self adhesive skin patch is also placed on the patient's body. An electrical lead from this patch is connected to an electrical energy source. As the abnormal site of the cardiac tissue is detected with the catheter's distal electrode, its corresponding electrical lead is switched from the monitoring/recording device to the electrical energy source for ablation. At this time, electrical energy can be delivered to the heart from the catheter tip that is in contact with abnormal heart tissue. The self adhesive patch on the patient's body is the return path of the electrical energy to the energy source. This known ablation procedure, using a self-adhesive patch as the return path of electrical energy to the energy source, may result in a significant level of electrical “noise” that is generated by the energy source during the energy delivery period. This “noise” superimposes itself to both surface electrocardiograms and intra-cardiac signals obtained from the catheter. Cardiac signals contaminated with such “noise” have been found difficult to monitor during energy delivery period.[0011]
• Intra-cardiac signals are commonly acquired for electrophysiology studies via a selected pair of a catheter's electrodes. The catheter is said to be used as a bi-polar probe when a cardiac signal is obtained between any pair of its electrodes. In some electrophysiology studies or cardiac mapping, however, the catheter is used as a uni-polar probe. When catheters of the prior art have been employed as a uni-polar probe, an additional reference electrode, that is not a part of the inserted catheter, is needed to complete the electrical circuit path. In such an arrangement, a second catheter is transveneously placed into the heart and this second catheter electrode functions as the reference electrode. U.S. Pat. No. 4,920,980 describes uni-polar and bio-polar application of cardiac catheters.[0012]
• Currently most widely used and commercially available cardiac diagnostic and ablation catheters are sold for “one-time-use-only”, and the entire catheter is discarded after a single use. Catheters of this type are relatively expensive. The catheter price and the convention of its “one-time-use-only” have an impact on the overall cost of cardiac electrophysiology and ablation procedures.[0013]
• Typically, known catheters have a generally cylindrical electrically non-conductive body which has a plurality of spaced annular surface electrodes on the distal end with a hemispherically-shaped tip electrode. Each electrode has a relatively fine electrically conductive wire attached thereto and embedded in the catheter's main body (tube) and extending from the distal end to the proximal end (catheter handle) where the electrical connectors such as plugs or jacks are provided to be plugged into a corresponding sockets provided in recording and monitoring devices.[0014]
• Typically, the main body of these catheters comprises a flexible tube constructed from polyurethane, nylon or some other electrically non-conductive flexible material with braided steel wires or other non metallic fibers in its wall as re-enforcing elements. An early example of such construction is that shown and described in U.S. Pat. No. 3,416,531 issued to M. L. Edwards. Catheters of this type are available in two general categories: a) those having a non-deflectable distal portion, an example of which is shown and described in U.S. Pat. No. 3,190,286 issued to R. W. Stokes, and b) those having a deflectable distal portion, as for example the catheter shown and described in U.S. Pat. No. 3,605,725 issued to I. E. Bentov. The distal portion of deflectable type catheters is typically made from non-braided flexible tube. This portion can be deformed into a variety of curved configurations with different radii of curvature by means of user input to a manual actuator on the catheter handle. The actuator is commonly internally linked to the catheter distal portion or the tip electrode by at least one steel tension or pull wire.[0015]
• The proximal end of the tension or pull wire(s) is connected to a tensioning or puller mechanism in the handle. The distal end of the tension or pull wire(s) is fixed to the catheter distal electrode or anchored to a point on the catheter distal portion.[0016]
• Catheters of this type also commonly comprise a flexible guide tube within the main body (tube) for bearing, in longitudinal or axial direction, the thrust or compression reaction of the flexible pull wire(s). An example of this latter type of configuration is shown and described in U.S. Pat. No. 3,906,938 issued to J. J. Fleischhacher and U.S. Pat. No. 3,521,620 issued to W. A. Cook. In the catheters of the prior art, such as those described in the aforesaid Cook and Fleischhacher patents, the inner flexible guide tube is formed by winding a tight coil of spring wire with the adjacent turns in contacting or closed relationship so that the inner guide tube will not compress longitudinally, but is freely flexible in bending. The tension wire(s) slides freely through this guide or coil spring type inner tube. The proximal end of the inner guide tube, in the aforesaid type catheters, is fixed to the catheter handle. The distal end of the inner guide tube is disposed in the distal portion of the catheter tubular main body. In one known catheter construction, one end of a bendable compression strut is seated on the distal end of the inner guide tube; and, the distal end of the pull wire(s) is fixed to the distal end of a bendable strut. Catheters employing such a strut are shown and described in the aforementioned Cook and Fleischhacher patents. See also U.S. Pat. No. 5,108,368 issued to Hammerslag for a catheter with a strut. In such known catheters, as tension is applied to the pull wire by the manual actuator on the catheter handle, the catheter distal portion assumes a curved configuration.[0017]
• One of the distinctive parts of deflectable distal portion catheters is the pull wire mechanism that is commonly located in the proximal end (handle) of the catheter. This mechanism usually includes a manual actuator by which the catheter distal portion can be deflected. The primary difference among the designs of deflectable distal portion catheters is in the catheter handle, more specifically, the tension or pull wire mechanism. This mechanism transmits the manual force applied to the actuator on the handle to the catheter distal portion via the pull wire(s), for formation of a desirable radius of curvature at the distal portion of the catheter. A catheter employing a partially rotating “wheel” or “cam” mechanism for pull wire(s) is disclosed in U.S. Pat. No. 5,273,535 issued to S. D. Edwards et al. A rectilinearly moving arrangement for the pull wire is disclosed in U.S. Pat. No. 4,960,134 issued to W. W. Webster, Jr. A shapeable or bendable catheter handle for curvature formation on the distal portion of the catheter is disclosed in U.S. Pat. No. 5,318,525 issued to Scott West et al. A rotating collar or thumb-wheel type actuator is disclosed in U.S. Pat. No. 3,416,531, issued to M. L. Edwards.[0018]
• The primary desirable performance features of the deflectable distal portion catheters are:[0019]
• Ease of operation: ergonomic design to provide for the best use of physician's hand anatomy for catheter handling and usage;[0020]
• A relatively low force requirement on the manual actuator of the catheter handle for formation of curvature at the catheter distal portion;[0021]
• A comfortable range of displacement of the manual actuator to provide for a full range of curvature formation at the distal portion of the catheter; and,[0022]
• A simultaneous curvature formation and curvature retention at the distal portion of the catheter by a single action of the physician's finger(s).[0023]
• The above desirable performance features for the catheters with deflectable distal portion have not been met by known commercially available catheters. The catheters of the prior art referenced in this document have not satisfied all of the desirable performance features mentioned above. For example, in the aforesaid U.S. Pat. No. 4,960,134, issued to Webster Jr., the sliding pull wire arrangement does not satisfy the low force requirement on the manual actuator of the catheter handle for formation of curvature at the catheter distal portion.[0024]
• In the aforesaid U.S. Pat. No. 5,273,535, issued to Edward et al, a catheter is disclosed with two manual actuators on the catheter handle; one actuator is employed for formation of curvature at the distal portion of the catheter; and, the other actuator is used for retention of curvature or locking. This catheter requires two independent manual actions on both actuators in order to form and retain a desirable radius of curvature on the distal portion of the catheter. Therefore, the Catheter of U.S. Pat. No. 5,273,535 (Edwards et al) fails to satisfy a simultaneous curvature formation and curvature retention at the distal portion of the catheter by a single action of the operators hand.[0025]
• Attempts have been made in the prior art catheters to provide a relatively laterally flexible distal portion for ease of its navigation through the vascular branches of the heart. In U.S. Pat. No. 5,203,772, issued to Gary R. Hammerslag et al, a steerable tip guide wire is disclosed for percutaneous transluminal insertion into the coronary vascular branches. The structure of the guide wire of the '772 Hammerslag et al, catheter comprises a spring coil wherein adjacent loops of the spring coil are “closed” or normally in contact with each other, except the loops that form the deflectable distal portion of the guide wire. The closed or contacting loops and the open or non-contacting loops of the guide wire of the '772 Hamemerslag et al construction provide an axially relatively non-compressible structure in the region of the stacked loops, with a relatively laterally flexible distal portion formed in the region of the open loops.[0026]
• U.S. Pat. No. 3,521,620 issued to William Cook discloses a similar guide wire structure having contacting and non-contacting portions with a deflectable tip for the same intended use as the aforementioned Hammerslag '772 guide wire.[0027]
• The cardiac catheters of the prior art are not only expensive but are solely for “one-time-use-only”. The catheter price and the convention of “one-time-use-only” increases the overall cost of electrophysiology and ablation procedures.[0028]
• Presently employed known methods of cardiac ablation procedure and presently employed known ablation catheters have the disadvantage of requiring an electrically conductive patch on the patient skin during the procedure. The function of this patch is to return the delivered electrical charge, from the catheter electrode inside the heart, to the ablation energy source.[0029]
BRIEF SUMMARY OF THE INVENTION
• It is an objective of the present invention to provide an electrophysiology catheter with a deflectable distal portion having the following features:[0030]
• An ergonomically comfortable range of motion of the manual actuator for a full range of curvature formation at the distal portion of the catheter;[0031]
• A low manual force requirement, applied by a single hand of the user, on the handle actuator for formation of curvature at the distal portion of the catheter;[0032]
• A simultaneous curvature formation and curvature retention capability at the distal portion of the catheter by a single action of the operator's hand;[0033]
• It is another objective of this invention to provide a catheter with a manual actuator on the catheter handle that is operated with the joint actions of index finger and the thumb in order to make the most efficient use of the anatomy of the operator's hand.[0034]
• A further objective of this invention is to provide an electrophysiology and/or ablation catheter incorporating a sensor in the catheter handle to detect the longitudinal displacement of the pull/push wires and which can be correlated to the radius of curvature at the distal portion of the catheter for monitoring purposes.[0035]
• Another objective of this invention is to provide an electromechanical drive system in the catheter handle to substitute the manual effort for formation of curvature at the distal portion of the catheter. The electromechanical drive system can also be controlled and manipulated via tele-communicated commands. The electromechanical system can also be over-ridden manually in the event of the failure of the drive unit.[0036]
• A further objective of this invention is to provide an electrophysiology catheter having a disposable blood contacting portion comprising the catheter main body and electrodes with a deflectable distal segment. A re-useable portion comprising the actuator handle with its associated tip deflecting mechanism which is easily attachable/detachable from the blood contacting portion.[0037]
• Another objective of the present invention is to provide an electrophysiology catheter incorporating an extra electrode on the catheter's exterior tube that can be employed as a reference electrode if desired for a uni-polar application of the catheter.[0038]
• A further objective of this invention is to provide an electrophysiology catheter having a deflectable distal portion with a self contained heating element within its distal electrode that can be employed for ablation procedures[0039]
• Another objective of this invention is to provide a stand-alone electrophysiology catheter having deflectable distal portion with a self contained heating element within its distal electrode and a self contained power supply in its proximal handle portion that can be employed for cardiac mapping and cardiac ablation procedures.[0040]
• A further objective of this invention is to provide an electrophysiology and/or ablation catheter with deflectable distal portion that can easily be manufactured in smallest possible size that can offer desirable bending characteristics at the catheter distal portion.[0041]
• A further objective of this invention is to provide an electrophysiology catheter having independent pull/push wire length adjuster units for each pull/push wire in the catheter handle for independent removal of slack from each individual pull/push wire.[0042]
• This invention provides a catheter employed for cardiac electrophysiology studies and/or cardiac ablation procedure. The catheter of this invention comprises of two main sub-structures. The first sub-structure is the blood contacting segment that includes: a) the catheter elongated tubular body, and b) the electrodes. The second sub-structure is the mechanism for formation of curvatures at the distal portion of the catheter. This mechanism includes: the catheter handle and its associated components.[0043]
• The catheter presented in this invention offers the following desirable features:[0044]
• A simultaneous curvature formation and curvature retention at the distal portion of the catheter by a single action of one hand of the user.[0045]
• An ergonomic handle for curvature formation at the distal portion of the catheter that makes the most comfortable and efficient use of the user's hand anatomy.[0046]
• A sensing unit within the catheter handle to be employed for displaying the radius of curvature at the catheter distal portion.[0047]
• In one embodiment of the present invention the blood contacting portion is disposable, i.e. used only once, thereby maintaining all safety and effectiveness requirements, yet the overall catheter use cost is significantly reduced by allowing re-use of the non-blood contacting portions.[0048]
• In one embodiment of this invention an ablation catheter with a self-heating element at its distal electrode is disclosed. Ablation with this catheter eliminates the need for a self-adhesive patch on the patient's body.[0049]
• In one embodiment of the present invention an additional electrode, that can be employed as a reference electrode, is incorporated in the catheter for enabling uni-polar application of the catheter, thereby eliminating the need for the placement of a second catheter in the patient's heart.[0050]
• The present invention offers the following additional attribute:[0051]
• An electromechanical battery operated drive system in the catheter handle as an alternative for the manual drive components of the distal portion curvature formation mechanism.[0052]
• The present invention utilizes a novel catheter construction which eliminates the compression loading of the inner guide tube and provides design flexibility and economies in construction.[0053]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view of the cardiac catheter presented in this invention;[0054]
• FIG. 2[0055]ais a overall view of the non-blood contacting segments of the catheter of FIG. 1;
• FIG. 2[0056]bis an enlarged view of the encircled distal portion of the non-blood contacting segment of the catheter of FIG. 1;
• FIG. 3[0057]ais an enlarged cross-section through the axis of inner guide tube of the catheter of FIG. 1;
• FIG. 3[0058]bis a left end view of FIG. 3a;
• FIG. 4 Shows a top sectional view of the slider-crank pull/push wire mechanism of the catheter handle of FIG. 1;[0059]
• FIG. 5 Shows an exploded view of the slider-crank pull/push wire mechanism of the catheter of FIG. 1;[0060]
• FIG. 6[0061]ais a plan view of the delta-shaped actuator of the catheter of FIG. 1;
• FIG. 6[0062]bis a section view taken along section-indicatingline6b-6bof FIG. 6a;
• FIG. 6[0063]cis a right end view of FIG. 6a;
• FIG. 7[0064]aShows an enlarged view of the slider block and the length adjuster of
• the pull/push wire mechanism of the catheter of FIG. 1;[0065]
• FIG. 7[0066]bis a section view taken along section-indicatinglines7b-7bof FIG. 7a;
• FIG. 7[0067]cis a section view taken along section-indicatinglines7c-7cof FIG. 7a;
• FIG. 7[0068]dis a section view taken along section-indicatinglines7d-7dof FIG. 7a;
• FIG. 8 Shows a plan sectional view of the catheter handle with the actuator partially rotated counterclockwise, thereby pulling one tension/compression member and pushing the other tension/compression member;[0069]
• FIG. 9 Shows a plan sectional view of an alternative embodiment for the catheter handle with a cam-follower mechanism;[0070]
• FIG. 10 Shows an enlarged view of the cam-follower mechanism of FIG. 9;[0071]
• FIG. 11 Shows a plan sectional view of the catheter handle with the cam-follower mechanism and the actuator partially rotated counterclockwise, thereby pulling one tension/compression member and pushing the other tension/compression member;[0072]
• FIG. 12 Shows a plan sectional view of the cam-follower mechanism with a circular disc actuator;[0073]
• FIG. 13 Shows the cam-follower mechanism with a circular disc actuator partially rotated counterclockwise, thereby pulling one tension/compression member and pushing the other tension/compression member;[0074]
• FIG. 14 Shows a plan sectional view of a further embodiment of a rack-pinion mechanism of the catheter handle;[0075]
• FIG. 15 Shows a plan sectional view of the catheter handle with the rack-pinion mechanism and the actuator partially rotated counterclockwise, thereby pulling one tension/compression member and pushing the other tension/compression member;[0076]
• FIG. 16[0077]aShows a plan sectional view of the catheter handle with rack-pinion mechanism having a circular disc actuator;
• FIG. 16[0078]bis a view similar to FIG. 16ashowing the disk actuator rotated in a counterclockwise direction from the position of FIG. 16a;
• FIG. 17 Shows a perspective view of yet another embodiment of the catheter handle with an electromechanical drive system and associated control components in two[0079]main segments60 and61;
• FIG. 18 Shows a perspective view of catheter handle of FIG. 17 with the two main segments attached together;[0080]
• FIG. 19 Shows a sectional view of the ablation catheter with a heating element within its distal electrode;[0081]
• FIG. 20[0082]aShows the blood contacting segment of the partially disposable catheter with a quick attachment/detachment plug;
• FIG. 20[0083]bis a view of the non-blood contacting segments of the catheter with a quick attachment/detachment jack;
• FIG. 20[0084]cShows the process of attachment/detachment of the blood contacting and
• non-blood contacting segments of the partially disposable catheter;[0085]
• FIG. 20[0086]dShows the segments of FIG. 20cfully assembled;
• FIG. 21 is an enlarged view of the electrical connector of[0087]handle182 of FIGS. 20band20c;
• FIG. 22 is an enlarged view of the electrical connector of the disposable[0088]blood contacting portion166 of FIGS. 20a,20c, and20d;
• FIG. 23 is an enlarged view of the assembly of the connectors of FIGS. 21 and 22;[0089]
• FIG. 24 Shows a perspective view of a cup-shaped distal electrode;[0090]
• FIG. 25 Shows a sectional view of the distal portion of the catheter main body and its connection to the cup-shaped distal electrode;[0091]
• FIG. 26 is an exploded view of another embodiment of the catheter handle with a Scotch-Yoke mechanism for moving the tension/compression members;[0092]
• FIG. 27 is a section view of the assembled mechanism of FIG. 26;[0093]
• FIG. 28 is a cross-section similar to FIG. 2[0094]bof an alternate embodiment of the non-blood contacting inner guide tube and its associated components;
• FIG. 29 is a view showing the embodiment of FIG. 28 in the deflected condition; and,[0095]
• FIG. 30 is a view showing the actuator handle assembly as grasped by the user's hand.[0096]
• FIG. 31 is a longitudinal cross-section of the distal portion of another embodiment of the electrophysiology/ablation catheter of the present invention;[0097]
• FIG. 32 is an enlarged view of a portion of FIG. 31;[0098]
• FIG. 33 is a longitudinal section view similar to FIG. 31 of an alternate embodiment of the invention of FIG. 31;[0099]
• FIG. 34 is a section view taken along section indicating lines[0100]34-34 of FIG. 33;
• FIG. 35 is a section view taken along section indicating lines[0101]35-35 of FIG. 33;
• FIG. 36 is a section view taken along section indicating lines[0102]36-36 of FIG. 33;
• FIG. 37 is a section view taken along section indicating lines[0103]37-37 of FIG. 33;
• FIG. 38 is a longitudinal section view of the catheter of FIG. 33 in a modified embodiment with the distal portion thereof undeformed during curvature;[0104]
• FIG. 39 is an enlarged view of the distal guide tube of the embodiment of FIGS. 33 and 38;[0105]
• FIG. 40 is a longitudinal section of an ablation catheter embodying the present invention and having a self contained power source and temperature control in the handle;[0106]
• FIG. 41 is an enlarged detail section view of the distal end of the ablation catheter of FIG. 40;[0107]
• FIG. 42 is a view similar to FIG. 40 showing an alternate embodiment of the distal end of te ablation catheter of FIG. 40;[0108]
• FIG. 43 is a longitudinal section view of an alternate embodiment of the ablation catheter of FIG. 40;[0109]
• FIG. 44 is an enlarged section view of the proximal end of te catheter of the present invention illustrating the attachment of the tension/compression members to the sliders;[0110]
• FIG. 45 is a longitudinal section view of an embodiment of the invention employing a self positioning friction brake for the actuator of te handle;[0111]
• FIG. 46 is a view similar to FIG. 45 showing the actuator in a position for causing curvature at the distal portion of the catheter;[0112]
• FIG. 47 is a schematic view of the sliders of the handle of he present invention showing a displacement transducer;[0113]
• FIG. 48 is a perspective view of the catheter of the present invention employing a collar thereon for enabling user to apply torque to the braided outer casing tube of te catheter;[0114]
• FIG. 49 is a view of the components prior to commencing assembly of the annular electrodes at the distal portion of the catheter;[0115]
• FIG. 50 is a view of the first step of assembly of the annular electrodes;[0116]
• FIG. 51 is a view of te step subsequent to the step of FIG. 50;[0117]
• FIG. 52 indicates a further step from the assembly of FIG. 51;[0118]
• FIG. 53 indicates a subsequent step from FIG. 52;[0119]
• FIG. 54 indicates the final step in assembling annular electrodes onto the catheter casing;[0120]
• FIG. 55 is a schematic for the temperature control of the ablation catheter of FIG. 40;[0121]
• FIG. 56 is a longitudinal section view of the positioning brake for the actuator of the handle of the catheter;[0122]
• FIG. 57 is an enlarged view of a portion of FIG. 56;[0123]
• FIG. 58 is an exploded view of the embodiment of FIG. 33[0124]
DETAILED DESCRIPTION OF THE INVENTION
• Referring now to the drawings, which are not intended to limit the invention, FIG. 1 illustrates a perspective view of one embodiment of the catheter assembly including the elongated flexible main body indicated generally at[0125]1. The catheter of this invention is comprised of two main components: i) a blood contacting segment that includes the catheter elongated exterior tubular body2 with a plurality of spacedelectrodes3 and adistal electrode5; and ii) a sub-assembly comprising the actuator mechanism for affecting the catheter distal curvature which includes a catheter handle and its associated components which is indicated generally at4. The blood contacting segment2 comprises of an elongated cylindrical electrically non-conducting preferably braided main exterior tube2 with a plurality of spacedannular surface electrodes3 on its distal portion and a hemispherically shaped solid or hollow cup-shapeddistal electrode5. The distal portion of the catheter denoted by the reference character “L” is a non-braided tube that is significantly more flexible or softer than the rest of main exterior tube2. Each of theelectrodes3,5 has a fineelectrical conductor wire6 attached thereto, which extends within the length of the catheter and throughhandle4 and outwardly to a corresponding one of the plugs/jacks8 disposed at the proximal end of thecatheter handle sub-assembly4.
• FIG. 2[0126]ashows thecatheter assembly1 of the present invention with the tubular body2 removed, thereby exposing the non-blood contacting segment of the catheter generally denoted byreference numeral9.
• When the first sub-structure[0127]2 is assembled over theinner guide tube9 of thecatheter handle4, thedistal portion10 of theinner guide tube9 is situated or disposed in the distal non-braided portion of the catheter exterior tube2. The catheter distal portion L of FIG. 1 assumes the same curved configurations as that of thedistal portion10 of theinner guide tube9 in response to the user manipulations of theactuator18 on thecatheter handle4.
• Referring to FIGS. 2[0128]aand2bthe non-blood contacting segment of the catheter of this invention includes:
• an inner guide tube indicated generally at[0129]9,
• a pair of tension/[0130]compression members11,12 comprising flattenedportions11′ and12′,
• a[0131]catheter handle4,
• and a plurality of[0132]electrical plugs8
• Referring to FIG. 2[0133]b, the entire length of theinner guide tube9 and its distal portion along thelength10 is disposed within the tubular body2 of FIG. 1. FIGS. 3aand3bshow the area of FIG. 2bin further enlargement wherein theinner guide tube9 is a flexible body made from spring wire in the region denoted byreference numeral14; and, is preferably formed as a tightly wound spring with adjacent coils contacting or closed windings. Theinner guide tube9 has disposed therein at least two tension/compression members in the form ofwires11 and12. The tension/compression members11,12 have a generally circular cross-section and extend preferably along the length of the elongatedinner guide tube9 and have a generally flattened ribbon-like configuration11′,12′ in theregion10 ofguide tube9. Theinner guide tube9 is formed to have generally circular cross-section. The windings of thedistal portion10 of theinner guide tube9 are permanently stretched or wound in the opened condition to provide an easily bendable structure.
• FIG. 4 shows an enlarged sectional view of the pull/push mechanism of the[0134]catheter handle4. The proximal end of theinner guide tube9 is seated on thecatheter handle nose15 which is attached to an end of block orbody113 ofhandle4. The tension/compression members11 and12 are each fixed at one end to the distal end of theguide tube9 in theregion10. The other end of each of the tension/compression members11 and12 is attached to one of the pull/pushlength adjuster units16 and17 which are slidingly mounted in grooves orslots114,115 mounted inblock113. With this arrangement, thedistal portion10 of theinner guide tube9 can be formed into a curved configuration by user movement of themanual actuator member18 in either transverse direction as indicated by the dashed outline in FIG. 4 aboutpivot pin19 by whichactuator18 is mounted to block113 in a through-slot116.
• FIG. 5 shows an exploded view of the pull/push mechanism removed from the[0135]catheter handle block113. Upon movement ofactuator18 themechanism4 is operative for applying tension to one of the tension/compression members11,12, and thereby affecting curvature formation at the distal portion L of the catheter of this invention. In one embodiment, this pull/push mechanism comprises two symmetrically coupled slider-crank linkages, hereinafter described, that share theactuator member18 which is preferably formed into a circular segment or delta shape with a hollowed outportion115 formed therearound.
• Referring to FIGS. 4 and 5, the[0136]actuator18 is disposed freely withinslot116 of thehandle block113. The proximal apex of thisactuator18 is hinged within the proximal front end of thehandle housing block113 by apin19 received throughaperture117 inactuator18. A pair of connectingrods20 and21 are received in the hollowed-outportion115 formed inactuator18 and are independently and symmetrically hinged each at one end throughaperture120,121 respectively to theactuator18 bypins22 and23 respectively, received throughaperture118,119 formed inactuator18. The opposite ends of the connectingrods20 and21 are each independently hinged each to an end of two separate andidentical slider links16 and17 bypins26 and27 respectively.Pin26 is received inaperture122 inslider16, withpin26 passing throughaperture123 inrod20; and, pin27 is received inaperture124 inslider17, and pin27 passes throughaperture125 inrod21. The end ofrod20 pivoted bypin26 is received and articulated in aslot126 formed inslider16; and, the end ofrod21 pivoted aboutpin27, is received and articulated in aslot127 formed inslider17.
• Referring to FIGS. 4 and 5 the slider links[0137]16 and17 each contain a pull/push member length adjuster unit indicated generally at24 and25 respectively.
• Referring to FIGS. 4, 6[0138]b, and6c, one of the pull/push or tension/compression members12 is shown as extending through hollow115 inactuator18 and is connected toslider17; and, pull/push member11 extends through hollow or slot115 and is connected toslider16.
• Referring to FIGS.[0139]7a7b,7c, and7d, one of the slider blocks16 is illustrated with its associated pull/push memberlength adjuster unit24 and its sub-components. The pull/pushmember length adjuster24 is disposed in aslider block16 having a longitudinally extending blindcylindrical cavity28.
• A generally cylindrical rod or adjusting member indicated generally at[0140]24 with an internally threaded hole or bore32 formed in the right end thereof is slidingly disposed freely within thecavity28 formed therein. The longitudinal position ofrod24 with respect to theslider block16 can be adjusted by the adjustingscrew34 threaded intobore32. A pull/push member fastener36 fixes the proximal end of a pull/push member12 (not shown in FIGS. 7a-7d) torod24. FIG. 7dshows an enlarged view of the typical hinged attachment between one end of the connectingrod20 andslider block16 bypin26. The function of each individual and independent pull/push member length adjusters such asadjuster24 is to independently remove the slack from the corresponding pull/push member11,12 that extends from catheter distal portion to thecatheter handle4.
• Referring to FIG. 8,[0141]actuator member18 is shown in solid outline and moved counterclockwise from the neutral position of FIGS. 1 and 4. In the position shown in FIG. 8,rod20 has movedslider16 rightward pulling on tension/compression member12.Rod21 has movedslider17 leftward pushing onmember11. The distal portion of the catheter of this invention can simultaneously be curved to different radii of curvature and retained at the desired curvature by a single action of the operator's finger. The slider-crank pull/push mechanism of the catheter handle of this invention operates near its “top-dead-center” or aligned position. An inherent property of a slider-crank mechanism operating near its top-dead-center position is a high-gain force amplification between the input force on the crank link oractuator18, and the output force on the slider link. Therefore, catheter of this invention requires a low actuating force on theactuator18, transmitted through the crank link, for assuming a full range of pull on one of themembers11,12 for affecting curvature at the distal portion of the catheter. Any curvature formed at the catheter distal portion by this mechanism will retain its configuration. This is because the elastic potential energy stored in the deflected distal portion of the catheter cannot provide a sufficient pull on the tensionedmembers11 or12 as the case may be to move the crank link and thus actuator18 to disturb the assumed configuration of the slider-crank mechanism which is near the “top-dead-center”.
• The geometric shape and dimensions of the delta-shaped[0142]actuator18 are designed to comfortably fit between the thumb and index fingers of an operator's hand. The relative magnitudes of these geometric dimensions, crank length (distance betweenpin19 and pins22,23) and the length of the connectingrods20 and21 are determined such that a comfortable range ofactuator18 rotation in two opposite directions results in formation of the full range of curvature, in opposite directions, at the distal portion of the catheter. It will be understood that rotation ofactuator18 in one direction is affected by the user's thumb of the hand grasping thehandle113; and, rotation ofactuator18 in the opposite direction is affected by at least one other finger of the same grasping hand.
• Referring to FIG. 8 the rotation of[0143]link18 in a counterclockwise direction to the position shown in solid outline has caused the rectilinear displacements of slider blocks16 and17 in two opposite directions, i.e.slider17 has moved to the left andslider16 has moved to the right. The movement ofactuator18 by the user to the position shown in solid outline FIG. 8 affects formation of a curvature in a counterclockwise direction, at the distal portion of the catheter, as the result of tension in the pull/push member12. It will be understood that a clockwise curvature formation can be achieved at the distal portion of the catheter when themanual actuator18 is rotated in a clockwise direction to the position shown in dashed outline in FIG. 8 which causesslider block16 to be moved to the left andslider block17 to be moved to the right when links orrods21,20 are moved to the positions shown respectively in dashed line.
• Referring to FIGS. 9, 10,[0144]11,12, and13 analternative embodiment4′ of the catheter handle is shown with a cam-follower type pull/push mechanism for affecting formation of curvature at the distal portion of the catheter upon movement ofactuator128. The pivoted delta shapedactuator128 is disposed to pivot freely aboutpin43 within thehandle113′.
• Referring to FIG. 10, the mechanism of[0145]handle4′ comprises two symmetrically coupledfollowers40 and41 disposed for sliding movement onblock113′ and with a singlerotating cam42 as the driver. Thecam42 is rigidly attached to the apex of the delta-shapedactuator128 for rotation therewith. Thecenter44 ofcam42 is pivoted within thecatheter handle body113′ about apin43.
• The two sliding[0146]followers40 and41 are driven bycam42. Each of the slidingfollowers40 and41 includes an adjustingscrew45 and46 respectively. The tip of each of these adjustingscrews45,46 are anchored to the cam profile and provides the contacting point between thefollowers40 and41 and the profile of thecam42. The distal ends of pull/push members11 and12 are individually fastened to the correspondingfollowers40 and41 respectively by thescrews47,48 threaded respectively intofollowers41,40. The slack in each pull/push member can independently be removed by adjusting thescrews47 and/or48.
• Each of the two[0147]followers40 and41 slides freely, in one of thestraight grooves49 and50 respectively, provided in the catheter handle113′.
• Referring to FIG. 11 the[0148]actuator member128 is shown rotated counterclockwise from the position shown in FIG. 10, whereincam42 has caused rectilinear displacements of the twofollowers40 and41 in opposite directions.Follower40 has been moved rightward tensioning pull/push member12; andfollower41 has been moved leftward pushing on pull/push member11. This movement offollowers40,41 results in formation of a curvature, in a counterclockwise direction, at the distal portion of the catheter. It will be understood that a clockwise curvature formation can be achieved at the distal portion of the catheter when themanual actuator128 is rotated in a clockwise direction to the position shown in dashed outline in FIG. 11.
• Referring to FIG. 12 an alternative arrangement of the actuator handle is shown generally at[0149]4″, having ahandle113″ and wherein the user actuator member comprises a circular disk-shapedactuator51 which is attached tocam42 in a torque-transmitting arrangement.Cam42 is shown in the neutral position in FIG. 12. It will be understood that user rotation ofactuator disk51 rotatescam42.
• Referring to FIG. 13, the[0150]actuator disk51 has been rotated in a counterclockwise direction as indicated by the arrow to placecam42 in the position shown in solid outline in FIG. 13. In FIG. 13,follower40 has been moved rightward from the position of FIG. 12, tensioning or pullingmember12; andfollower41 has been moved leftward from the FIG. 12 position, resulting in pushing onmember11.
• Referring to FIG. 14 a further alternative embodiment of the actuator handle is shown generally at[0151]4′″ for the catheter of this invention wherein handle orbody130 has a groove or through-slot132 with a pair of parallel oppositely disposedsliders134,136, disposed therein, each having a rack gear formed thereon as denoted respectively byreference numerals138,140. Rack gears138,140 are engaged on opposite sides of acommon pinion gear142.Pinion142 rotates freely within the catheter handle130 aboutpin144 secured throughbody130. Eachslider134,136 includes a pull/push member anchoring orattachment screw146,148 to which one end of pull/push members11,12 are attached respectively. The apex of a delta-shapedmanual actuator150 is fixed to thepinion142 in torque transmitting arrangement and is shown in the neutral position in FIG. 14.
• Referring to FIG. 15 the[0152]manual actuator150 is shown rotated counterclockwise from the position of FIG. 14, resulting in the rectilinear displacements of theslider136 to the left andslider134 to the right, pulling on pull/push member12 and pushing on pull/push member11. The proximal ends of the pull/push member11 and12 are fixed to thesliders136,134 respectively by fasteners such asscrews146 and148. It will be understood that the distal end of the pull/push members11 and12 are fixed to the distal ends of the elongatedinner guide tube9. It will be also understood that theactuator150 may also be moved in the clockwise direction to the position shown in dashed outline in FIG. 15, resulting in opposite movement ofslider134,136. With either counterclockwise or clockwise rotations ofactuator150 the rectilinear displacement of the slider racks134,136 is in opposite directions and results in formation of curvature at the distal portion of the catheter.
• Referring to FIG. 16([0153]a), another embodiment of the actuator handle is indicated generaly at4″″, whereinpinion gear142 is attached to acircular actuator152 in torque transmitting arrangement.
• Referring to FIG. 16([0154]b), as the user rotatesactuator disk152 in a counterclockwise direction as shown by thearrow slider136 is moved leftward, andslider134 is moved rightward from the neutral position shown in FIG. 16(a).
• Referring to FIG. 17, another alternative embodiment has the handle assembly that is indicated generally at[0155]154.Handle assembly154 includes an electromechanical battery operated drive system that is substituted for the manually actuated pull/push mechanism of the embodiments4-4″″. Theembodiment154 comprises two main subsystems indicated generally at60 and61. Thefirst sub-system60 of theembodiment154 is the “lower” portion of the catheter handle that includes:
• a[0156]cylindrical housing62, having disposed therein abattery63;
• an[0157]electrical motor64, which is connected tobattery63 disposed at the right hand end ofhousing62;
• a speed reduction gear box[0158]65, driven bymotor shaft156, and which has anoutput drive shaft66;
• a multi[0159]connector junction plug67 is disposed on the front end of thehousing62; and,
• an[0160]electronic module68 is provided on this end ofhousing62 adjacent tobattery63 for receiving computer and/or tele-communication signals.Battery63 can either be disposable or re-chargeable.
• The[0161]second sub-system61 has a multi connectorproximal end jack69 disposed in the right hand end ofhousing73. All electrical wires of the catheter, including the electrode conductors are terminated to the terminals (not shown) ofjack69. The corresponding electrical leads ofsub-system60 are terminated at terminals (not shown) ofplug67.
• The[0162]electrical motor64 and motor speed reduction gear box65 are disposed within thecylindrical housing60 adjacent the left hand end. Thecoupling drive shaft66 extends from the gear box65 through acylindrical collar70 in the left end of thehousing62. Thedrive shaft66 can freely rotate within thefront end collar70 of thehousing62. The end of thedrive shaft66 is coupled to theleft hand end71 of thecore72 of thesub-system61. In operation either clockwise or counterclockwise rotation of thedrive shaft66 results in drivingcore mechanism72 and a corresponding curvature formation respectively at the catheter distal portion.
• The[0163]second sub-system61 of theembodiment154 comprises the front or left hand portion of the catheter handle end and includes:
• a[0164]cylindrical housing73;
• a manual back-up actuator[0165]74 in the form of a tubular member disposed concentrically overhousing73;
• a motor control switch[0166]75;
• the multi[0167]connector junction jack69 is disposed inside the right hand end of thecylindrical housing73;
• a connecting rod or[0168]pin76 interconnects manual drive actuator74 tocore72 through aslot82 formed inhousing73;
• a[0169]front bearing support77 is disposed inhousing73 adjacent the left end thereof;
• a rear bearing support[0170]78 is disposed inhousing73 adjacent the right hand end thereof; and,
• an[0171]angular displacement sensor79 is disposed inhousing73 and located at the right hand end thereof for sensing rotation ofcore72 with respect tohousing73 ofsub-system61.
• The[0172]core72 ofsub-system61 includes two identical pull/pushmember length adjusters158,160 which are each respectively connected to one of the pull/push members11,12 of thecatheter1. These adjusters are disposed, side-by-side, and parallel to the longitudinal axis of thehousing73, within and near the surface of the cylindrical solid portion of thecore72. Thecore72 of thesub-system61 has aleft end shaft80 extending therefrom and a right end shaft81 extending therefrom in a direction oppositeshaft80 and aligned therewith.Shaft80,81 are supported byrotary bearings77 and78 respectively disposed inhousing73; and thus, the core72 can freely rotate within thehousing73 about its longitudinal axis.
• A backup manual actuator[0173]74 comprises a short cylindrical tube that is disposed over the front portion of thehousing73 and can freely rotate about the longitudinal axis of thehousing73. Anactuator slot82, extending circumfrentially and perpendicular to the longitudinal axis ofhousing73, is provided on the upper half of thehousing73. The backup manual actuator74 is linked to the front portion of the core72 with connecting rod orpin76 throughslot82. The width of theslot82 is chosen to guide but permit free movement ofpin76. The core72 can thus be rotated about its longitudinal axis with respect tohousing73 ofsub-system61 by the rotation of the backup manual actuator about the same axis.
• It will be understood that the proximal end of each pull/[0174]push member11 and12 is fastened to a corresponding one of the pull/pushmember length adjusters158,160 byscrews162,164 respectively.
• Rotation of[0175]core72 about its longitudinal axis will pull one of the pull/push members11 or12, and compresses the other one, resulting in formation of curvature at the distal portion of thecatheter1.
• The multi[0176]connector junction jack69 and multi connector junction plug67 serve as both the mechanical and electrical coupling between the sub-systems60 and61.
• When[0177]sub-systems60 is connected to sub-system61, the left end of thedrive shaft66 is engaged with the right hand end ofcore72. The motor can be energized and controlled for forward and reverse rotation by a switch75 provided on the exterior ofhousing73. As themotor64 is activated, thedrive shaft66 will rotate the core72 which results in formation of curvature at the distal portion of the catheter.Angular displacement sensor79, disposed in thehousing61, is employed to provide predetermined limits for the angular rotation ofcore72 as an indication of the radius of curvature at the distal portion of the catheter. The actuator or servomotor driven cardiac catheter handle154 of FIG. 17 can also be controlled remotely via computer and/or tele-communication systems and thus has application for various other cardiac catheter procedures.
• Referring to FIG. 18 the servomotor operated[0178]electromechanical catheter handle154 is shown as a complete assembly with its twosubassemblies60 and61 connected together withplug67 engagingjack69 as shown in dashed line.
• Referring to FIG. 19 the distal portion of a further embodiment of the catheter of this invention indicated generally at[0179]170 and is shown in the curved condition. The embodiment of FIG. 19 is configured such that it can be employed for cardiac ablation and intra-cardiac mapping procedures.
• This embodiment indicated generally at[0180]170 in FIG. 19 is a modified version of thecatheter1 presented in FIG. 1 of this invention. The modification is applied on the catheterdistal tip electrode5 of the FIG. 1 embodiment and is described as follows.
• Referring to FIG. 19 an electrical heating element[0181]100 is disposed within the distal tip cup-shapedelectrode172. The heating element100 is energized by a battery disposed in the catheter handle4 or by an external electrical power supply (not shown). The temperature of the distal electrode is controlled by adjusting the electrical current flow through the heating element100. Electricallead wires101 and102 are connected to the heating element100 and extend from the heating element100 within the interior of tubular body2 to the proximal end and outwardly to the power supply and temperature control switch (not shown).
• The[0182]embodiment170 includes an additionalannular reference electrode103 on the catheter main exterior tube2 for a uni-polar application of the catheter during intra-cardiac mapping procedures. In addition, thecatheter170 may include a blood-clot sensor or detector (not shown) and a temperature indicator (not shown) in thecatheter handle4. The purpose of blood clot sensor is to stop or reduce the delivery of electrical energy to the heating element during ablation procedures.
• Referring to FIGS. 20[0183]athrough20da further embodiment180 of the catheter of the present invention is illustrated and has the feature that the blood contacting portions are disposable; and, thus, the embodiment180 is particularly suitable for cardiac electrophysiology/ablation procedures. The embodiment180 is a modified version of the catheter presented in FIG. 1 of this invention. The modification is applied in two parts. The first modification pertains to the shape of thedistal tip electrode176 and its connection to the mainexterior tube172 of the catheter which, along with aproximal end connector181 having internal connector rings188 comprises the blood contacting components or sub-assembly indicated generally at166. The second modification involves the method of connecting thesubassembly166 of blood contacting components i.e. a mainexterior tube172, spacedelectrodes174 anddistal electrode176 to the non-blood contacting components indicated generally at168 comprising aninner guide tube178 and catheter handle indicated generally at182.
• The first modification is illustrated in FIG. 20[0184]a. FIG. 24 shows the modifieddistal electrode176 employed in the FIG. 20aembodiment as having a cup-shaped configuration. Thedistal electrode176 is formed as a cylindrical shell with ahemispheric dome110 on the closed end and a plurality, preferably four, of circumfrentially spacedprongs111 extend outwardly in an axial direction from the other open end of the cup-shapeddistal electrode176.
• Referring to FIG. 25 the cup-shaped[0185]electrode176 is sleeved partially over the distal portion of the mainexterior tube172 of the catheter. Theprongs111 are bent inwardly perforating the wall of the mainexterior tube172, extending inwardly and again bent over the inner wall of the mainexterior tube172 to form a “stapled-type” connection between the cup-shapeddistal electrode176 and the mainexterior tube172. At least one wire112 is wrapped around one of theprongs111 and secured to the inner wall of the mainexterior tube172 to provide electrical connection toelectrode176 and also provides a redundant securement totube172.
• Referring to FIGS. 20[0186]a-20d, the second modification for the disposable catheter180 is described as follows. The two sub-assemblies, namely theblood contacting subassembly166 and non-blood contactingsub-assembly168 of catheter180 of this invention are individually fabricated such that they can function independently as intended.
• Referring to FIG. 20[0187]a, the first sub-assembly orblood contacting unit166 of this embodiment180 comprises of the mainexterior tube172 of the catheter, the spacedsurface electrodes174 anddistal electrode176, the electrical wires of the surface electrodes and the combined electric coupling andstructural connector181. All electrical wires of thecatheter tip electrodes174,176 terminate to thecoupling181.
• Referring to FIG. 20[0188]bthe secondnon-blood contacting sub-assembly168 of embodiment180 is illustrated.Second sub-assembly168 comprises theinner guide tube178, a combination electrical connector andstructural coupling183, a catheter handle indicated generally at182 and catheter electrical lead connector end plugs184. The nonblood contacting sub-assembly168 can readily be coupled to theblood contacting subassembly166; and, the two can be locked together by thecouplings181 and183 which may be threaded or quick-lock type to form a assembly180 that can function as a complete catheter.
• Referring to FIG. 20[0189]cthe coupling of the two sub-assemblies of the catheter of this invention is shown with guideinner tube178 ofsubassembly168 partially inserted intotubular casing172 ofsub-assembly166. The coupling action of the twosub-assemblies166,168 can also be done during the cardiac electrophysiology/ablation procedures by the physician. This allows the physician to select from variety of second non-blood contactingactuator sub-assemblies168 that offer different distal portion curvature configurations for the sameblood contacting sub-assembly166. In the embodiment180, the disposable segment of the catheter comprises only the blood contacting sub-assembly166 shown respectively in FIG. 20a.
• Referring to FIG. 20[0190]d, the catheter of embodiment180 is fully assembled withconnector181 engaged withconnector183. It will be understood that the electrical lead from each of theelectrodes174,176 is connected to one of the electrical terminal rings186 onconnector183. Each of therings186 makes electrical contact with a correspondingly located terminal annular188 provided inconnector181 ofsub-assembly166.
• The catheter of this embodiment[0191]180 can thus significantly reduce the price of cardiac catheters and thus an overall cost reduction of the cardiac electrophysiology and ablation procedures.
• Referring to FIG. 21 the external[0192]electrical connector186 ofactuator handle sub-assembly182 of FIGS. 20b,20c, and20dis shown where each of theelectrical connector186 has an end of one of thelead wires230,232,234,236, attached thereto. It will be understood tat each of the leads230-236 has its opposite end connected to one of theconnectors184 externally ofhandle182.
• Referring to FIG. 22 the[0193]electrical connector181 of disposable blood contacting subassembly180 of FIGS. 20a,20c, and20dis shown enlarged with an internal tubular sheath orliner238 defining anannular space240 betweenliner238 and the body ofconnector181. The proximal end of the mainexterior tube172 is received and retained, as for example by weldment into areduced diameter neck242 formed onconnector body181,Liner238 has a reduceddiameter neck243 which extends a predetermined distance into mainexterior tube172. A plurality of axially spacedelectrical terminals244,246,248,250 are disposed on the inner periphery ofliner238 with each of its terminals244-250 having portions thereof extending outwardly through the wall ofliner238 and into theannular space240. A plurality ofelectrical leads252,254,256,258 is received in theannular space240 and each has respectively one end thereof connected to one of the terminals244-250. Each of the leads252-258 extends through annular space betweenliner238 and the inner periphery of mainexterior tube172 and continues to the distal portion oftube172. It will be understood that each of the leads252-258 is respectively connected to one of theelectrodes174,176 on theblood contacting sub-assembly166.
• Referring to FIG. 23,[0194]connectors181,183 are shown assembled with the ring.electrical connectors186 ofconnector183 each making contact with one of the connector terminals244-250 for providing electrical continuity between electrical leads pairs230 and254,232 and252,234 and256,236 and258 thereby connecting each of theexternal connectors184 with one of theelectrodes176174 on the distal portion of the disposableblood contacting subassembly166.
• Referring to FIG. 26 an alternative embodiment indicated generally at[0195]190 of the catheter handle sub-assembly is shown in exploded view without the handle body with a Scotch-Yoke type pull/push mechanism for affecting formation of curvature at the distal portion of the catheter upon movement of theactuator member192. The preferably delta shapedactuator192 is disposed to pivot freely aboutpin194 within the handle's body (not shown). It will be understood thatmember192 may be disposed for pivoting in a handle slot in a manner similar toactuator member18 of FIG. 1.
• Referring to FIGS. 26 and 27, the mechanism of[0196]handle190 comprises two symmetrically coupledsliders196 and198 disposed for sliding movement ingroove200 formed inhandle body202 and with the singlerotating actuator192 as the driver thereof. Thesliders196 and198 are linked to the delta-shapedactuator192 by non-articulating pins orlinks204 and206.
• Referring to FIG. 26 pins or[0197]links204,206 are formed generally at a right angle at one end, with the ends each received in a transverse bore provided in the side ofsliders196,198 withlinks204,206 extending fromsliders196,198 outwardly in the direction of sliding movement. The opposite or free ends oflinks204,206 are also formed at right angles in a common direction orthogonal to the links-receiving bores in thesliders196,198 and as denoted byreference numerals208,210. Thelinks204,206 are thus non-articulatable in a center plane passing through bothsliders196,198.
• The[0198]actuator192 has a pair of spacedslots212,214 elongated in a direction transverse to delta-shapedactuator192.Link end208 is received inslot212; and, linkend210 is received inslot214. It will be understood that user movement of theactuator192 in the direction of the block arrows in FIG. 26 will cause relative movement of the link ends intoslots212,214 and will result in pulling one and pushing the other of thesliders196,198 ingroove200 ofbody202.
• The proximal ends of tension/compression (pull/push)[0199]members11 and12 are individually received in a closely fitting tubular sleeve denoted respectively216,218 which are in turn received individually in a longitudinal bore denoted respectively220,224 provided in each of thesliders196,198. Thesleeves216,218 may be secured to pull/push members11,12 respectively by weldment if desired, as, for example by soldering or brazing. Thesleeves216,218 and the proximal ends ofmembers11,12 are secured respectively in slider bores220,224 by engagement with set screws torqued into threaded cross holes provided insliders196,198, one such cross hole is visible in FIG. 26 at230.
• Each of the two[0200]sliders196 and198 slides freely, in thestraight groove200 provided in thecatheter handle202.
• Referring to FIG. 27 the actuator member is shown rotated counterclockwise from the position shown in FIG. 26, wherein[0201]actuator192 has caused rectilinear displacements of the twosliders196 and198 in opposite directions.Slider196 has been moved leftward pushingmember11; andslider198 has been moved rightward pullingmember12. This movement ofsliders196,198 results in formation of a curvature, in a counterclockwise direction, at the distal portion of the catheter. It will be understood that a clockwise curvature formation can be achieved at the distal portion of the catheter when themanual actuator192 is rotated in a clockwise direction to the position shown in dashed outline in FIG. 27.
• Referring to FIGS. 28 and 29, an alternative preferred embodiment of the[0202]non-blood contacting actuator168 of FIG. 20bis shown generally at260 with aninner guide tube262 formed of helically wound wire similar toinner guide tube178 of FIG. 20b. The distal end ofinner guide tube262 has a tip plug ormember264 attached securely thereto, such as by weldment. A pair of pull/push or tension/compression members268,266 are received intube260, with a portion of each denoted266′,268′ integrally flattened to a ribbon-like configuration, with the end of each ribbon secured to tip264 as by weldment. Aguide bushing270 has a rectangular throughbore271 formed therein has theribbons266′,268′ slidably received therein, withguide bushing270 adjacent to the proximal end of ribbon-like portions266′,268′. Theguide bushing270 is secured, such as by weldment, to the distal end of theinner guide tube261 with contacting coils (closed windings).
• An annular collar or[0203]sleeve member272 is received over ribbon-like portions266′,268′ and serves as a kinematic junction of the ends of266′,268′. Thecollar272 is secured, such as by weldment, to bothribbons266′,268′ at a predetermined distance between theguide bushing270 andtip plug264. Theactuator260 is shown in relaxed or neutral condition in FIG. 28.
• Referring to FIG. 29, tension has been applied to[0204]member266 causingribbon266′ to pull oncollar272 bending the262 betweenguide bushing270 andcollar272; however the portion oftube262 betweencollar272 andtip264 remains straight or un-deflected.
• It will be understood that the[0205]inner guide tube261 of FIG. 29 or9 of FIG. 3aof the present invention is not loaded in compression when one of themembers266,268 of FIG. 29 or11,12 of FIG. 3ais tensioned. Unlike the known catheters, the catheter of the present invention transmits the compression loading of the kinematic junction directly to the one of push/pullmembers266,268 of FIG. 29 that is not being tensioned by the manual actuator and does not use a separate compression strut member to transmit compression load to the inner guide tube as in the case of known catheters. It will be understood that in the embodiment of FIGS. 28 and 29 the kinematic junction comprises of the weldment ofcollar272 to266′,268′; and in the embodiment of FIG. 3athe kinematic junction comprises the attachment of the pull/push or tension/compression members11′,12′ to the distal end ofportion10 ofinner guide tube9.
• The present invention thus provides a low cost cardiac catheter which has a disposable blood-contacting segment removable from the actuator assembly which is re-useable. The actuator utilizes a pair of tension/compression members which are flattened integrally at the distal end region for improved deflection characteristics. The actuator handle is grasped in the user's hand and catheter distal region deflection in one direction is affected by movement of a handle actuator member in one direction by the user's thumb; and catheter deflection in the opposite direction is affected by movement of the handle actuator member in the opposite direction by the other finger(s) of the same hand.[0206]
• FIG. 30 is a view showing the actuator handle assembly as grasped by the user's hand.[0207]
• Referring to FIGS. 31 and 32, another embodiment of the catheter of thee invention is indicated generally at[0208]300 and has a solid distal electrode that in the present practice of the invention has been formed satisfactorily from platinum material and is denoted byreference numeral302. Theelectrode302 has the distal ends of a pair of tension/compression members304,306 secured therein as for example by weldment which in the present practice of the invention comprises a brazed joint308. It will be understood that the distal portions of the tension/compression members304,306 have a generally flattened rectangular transverse cross-sections as illustrated in FIG. 32.
• A spacer means[0209]310 is disposed between the flattened ends of tension/compression members304,306 in the present practice of the invention. The spacer means310 comprises a wave-shaped flat spring having a generally rectangular transverse cross-section with an end thereof secured between the tension/compression members304,306 in a kinematic junction indicated generally at312. Thekinematic junction312 is formed by asleeve314 which in the present practice of the invention is formed of stainless steel tubing received over the tension/compression members at the kinematic junction having the end of the wave-shapedspring310 and is secured and formed by weldment which in the present practice of the invention comprises brazing as denoted by reference numeral316. It will be understood that thespacer310 serves only to maintain the transverse or lateral spacing of the tension/compression members304,306 on the side ofkinematic junction312 away from thedistal electrode302. It will be understood that except for the end ofspacer310 which is brazed intosleeve314, the wave-shapedflat spring310 is otherwise free-floating between the tension/compression members304,306.
• It will be understood that the tension/compression members' transition to a round or wire-like configuration is denoted by[0210]reference numerals304′306′ in a manner similar to the embodiment of FIGS. 2band3aof the present invention. In te embodiment of FIGS. 31 and 32, a thin wallplastic tubing318 is received over the distal flattened portions of the tension/compression members304,306 and the plastic tube is received over, in closely fitting engagement, an annular sleeve orcollar320 secured to the weldment or brazed joint of the distal electrode. In the present practice of the invention, thecollar320 is formed of stainless steel material. Theplastic tube318 extends over theround cross-section portions304′,306′ of the tension/compression members; and, thetube318 also extends over the distal end of aninner guide tube322 wich in the present practice of the invention comprises a closed coil stacked helical spring member.
• A thin wall preferably stainless[0211]steel tubular member324 is received over the tension/compression members304′,306′ and thetube324 has one end thereof crimped to a flattened cross-section as denoted byreference numeral326 and themember324 serves to constrain the tension/compression members from twisting or rotation with respect to theouter casings325 and330 during flexing of distal portion of the catheter. An outer blood-contacting casing comprising a tubularflexible plastic member325 has the distal end thereof is attached to a reduced diameter portiondistal electrode302 and extends over thetube318 and has the opposite end thereof received over a thin-wall shortannular sleeve member328 whien serves to join theouter casing member325 with theouter casing330 which is re-enforced with braided material as denoted byreference numeral332. With reference to FIG. 31, a plurality of annular electrodes are received over the outer periphery of thecasing member325 and are disposed in spaced arrangement therealong with each of the electrodes having an electrical wire lead member connected thereto as denoted byreference numeral334,336 for the electrodes and338,340 for the wire leads in FIG. 31.
• It will be understood that the[0212]catheter300 is intended to be operated by the handle mechanism illustrated in FIG. 1 wherein the slider members are connected to the tension/compression members304,306 such that movement of the actuator causes one slider to tension one of themembers304,306 and the other of the members is placed in compression; and, reversed movement of te actuator wherein the handle causes the other of the tension/compression members to be tensioned and the one to be placed in compression.
• Referring to FIGS. 33 through 37, another embodiment of the electrophysiology/ablation catheter of the present invention is indicated generally at[0213]400 and has a construction generally identical to tat of thecatheter300 of FIG. 31 with the exception that theinner guide tube302 is formed of plastic material and has two generally circular longitudinally extendinglumens404,406 formed thereto to which are received the tension/compression members408,410.
• It will be understood that in the[0214]embodiment400, a tension/compression members404,406 have flatteneddistal portions404′ and406′ as illustrated in detain in FIGS. 36 and 37; and, theembodiment400 also employs the spacer means comprising a wave-shapedflat spring416 with one end thereof secured in akinematic junction426 in a manner identical to that ofembodiment300 of FIG. 31.
• It will be understood that in the[0215]embodiment400, the inner guide tube is received in the end of the thin wallplastic tube418 which corresponds to thetube318 in the embodiment of FIG. 31.
• Referring to FIGS. 39 and 58, the[0216]embodiment400 of the present invention is illustrated in exploded view in the preferred form wherein the flexibleplastic tube418 has three (3) lumens formed therethrough with wave-shapedflat spring spacer416 received through the central lumen and each of the tension/compression members' flattenedportions404′,406′ received through a lumen disposed respectively on opposite sides of the central lumen.
• Referring to FIG. 39, the central lumen is denoted by[0217]reference numeral420 and the side lumens are denoted byreference numerals422 and424. In theembodiment400, the annular tube member forming the kinematic junction is denoted byreference numeral426; and, the outer casing portion having te electrodes thereon is denoted byreference numeral428 and the braided portion of the outer casing is denoted byreference numeral430 and the distal electrode is denoted byreference numeral432.
• In the[0218]embodiment400, the flattened tube portion denoted byreference numeral434 is optional in as much as the construction of theinner guide tube402 is operative to prevent twisting of the tension/compression members with respect to theouter casings428 and430.
• Referring to FIG. 38, another embodiment of the catheter of FIG. 33 is illustrated in longitudinal cross-section in its distal portion and denoted generally at[0219]500. Thecatheter500 is identical to thecatheter400 of FIG. 33 with the exception that sleeve orannular member502 forming the kinematic junction of theends504,506 of the tension/compression members505′,506′ and the end of the wave-shapedflat spring spacer508 is spaced a distance further from thedistal electrode510.
• The[0220]kinematic junction512 is formed by brazing in distal ends of the tension/compression members504,506 and the distal end of the wave shapedflat spring spacer508 in theannular member502. By virtue of the distance between thedistal electrode510, and the kinematic junction512 a region is created, between theelectrode510 andkinematic junction512, which remains un-deformed during lateral deflection of the catheter by operation of the actuator for pulling and pushing on the tension/compression members504′ and506′. In theembodiment500, an additional flexible tube is inserted over the flexible tube518 (which corresponds to the tube418) and the additional tube denoted byreference numeral520 which provides additional stiffness to the region of the catheter betweenkinematic junction512 and the end of thetube518 remote fromelectrode510.
• Referring to FIGS. 40 and 41, another embodiment of the invention is indicated generally at[0221]600; and, the distal portion of thecatheter600 is identical to theembodiment300,400 as described hereinabove except the distal electrode of thecatheter600, denoted byreference numeral602, has embedded therein a heating element604 to enable the catheter to be employed as an ablation catheter. It will be understood that the heating element604 has a pair of electrical power leads606,608 attached thereto and which extend within the outer casing610 to the proximal end of the catheter and into thehandle612 for connection to a power supply and temperature control module provided therein and denoted by reference numeral614 in FIG. 40.
• The[0222]embodiment600 of FIG. 41 also includes atemperature sensor616 embedded in thedistal electrode602, which is the present practice of the invention may be a solid state junction device which has leads618,620 extending within the casing610 to the proximal end of the catheter. Thesensor616 is intended for use in remote monitoring of the temperature of thedistal electrode602 during ablation procedures.
• Referring to FIGS. 42 and 43, an alternate version of the[0223]embodiment600 is illustrated wherein the catheter assembly indicated generally at700 as the construction thereof, identical to theembodiment600 with the exception that catheter of700 does not include a heating element in itsdistal electrode702; and instead, the temperature of thedistal electrode702 is controlled by a radio-frequency power supply/control module that is external to the catheter of700.
• It will be understood that a fiber optic temperature sensor can be used instead of the solid state junction[0224]716 in an alternate embodiment ofcatheter700; and, a fiber optic cable extends withinouter casings706 and707 to the proximal end of the catheter.
• Referring to FIG. 44, another embodiment of catheter handle is indicated generally at[0225]800 and has the proximal end of theguide tube802 received in atubular member804 in a closely fitting arrangement with the tension/compression members806,808 extending from the proximal end of he guidetube802 and through thetube member804 for connection to a pair of slider blocks810 and812 which corresponds in shape and function to thesliders16 and17 of FIG. 5. The proximal ends of each of the tension/compression members806,808 each have a closely fitting thin wall preferablystainless steel tube814,816 received respectively thereover.
• The proximal ends of the tension/[0226]compression members806,808 with theirrespective tubes814,816 are each secured in one of the slider blocks810,812 by aset screw818,820 respectively which deforms the thin wall oftubing814,816 and clamps the tubing and the respective tension/compression members806,808 to the slider blocks810,812.
• Referring to FIG. 45, the[0227]embodiment800 of catheter embodies afriction brake member822 contained in thehandle824 byinterior projection826 which maintains themember822 in frictional contact wit the curved edge of theactuator828 which corresponds in shape and function to actuator18 of embodiment of FIG. 1. In the present practice of the invention themember822 is formed of elastomeric material to provide inherent spring compression of the material against the curved edge of theactuator828; and, themember822 by virtue of the sliding friction on the curved edge of theactuator828 serves to retain theactuator828 in its user selected position after movement from the neutral position shown in FIG. 45.
• Referring to FIG. 46, the embodiment of[0228]catheter800 illustrated in FIG. 45 is shown with the actuator moved to a user selected position for curving the distal portion of the catheter wherein themember822 has deformed resiliently to the position of the curved edge of theactuator828 but is maintaining frictional contact therewith.
• Referring to FIGS. 56 and 57, another version of the frictional retaining member is illustrated in the embodiment indicated generally at[0229]900 wherein theactuator902 corresponds to theactuator member828 of theembodiment800; and, thecurved edge portion904 of theactuator902 has engaged therewith the end of a spring loadedplunger906 which is received in atubular housing908 which in turn has acompression spring910 received therein for biasing theplunger906 in contact with thecurved edge904 of theactuator902. Thetubular member908 is disposed in thehandle912 betweenguide projections914. It will be understood that theplunger906 serves the same function as themember822 of theembodiment800 of FIG. 45.
• Referring to FIG. 47, another embodiment of the catheter handle is indicated generally at[0230]4′ wherein theslider16′ and17′ have awiper tube290 attached thereto which is operative to vary the electrical resistance in apotentiometer292 for providing an electrical indicator signal corresponding to the position of thesliders16′,17′ from which the curvature of the distal portion of the catheter may be calibrated for a catheter of known parameters.
• Referring to FIG. 48, a compressible collar or[0231]spool296 is received over the proximal portion of the braided exterior casing2 wherein thecollar296 is in frictional sliding engagement with braided exterior casing2. Thecollar296 is preferably formed of soft elastomeric or spongy material. The user may press thecollar296 onto the braided outer casing for readily applying torque thereon for twisting the braided outer casing. As shown by the dashed outlines of FIG. 48, themember296 may be moved by the user longitudinally along the braided outer casing tube2 of the catheter for selecting the point of application of the user's applied torque to the catheter's braided outer casing tube.
• Referring to FIGS. 48 through 54, the technique for installing one of the annular electrodes over the outer casing at the distal portion of catheter is illustrated and will be described hereinafter with respect to FIGS. 49 through 54. Referring to FIG. 49, an[0232]annular electrode1000 has an electricalconductive lead1002 attached to the interior periphery thereof and extending outwardly therefrom. The flexibleouter casing tubing1004 has an end thereof received over a rigid tubing such as1008 which serves as a part of a holding vise for thetubing1004. The free end of theelectrical lead1002 is then passed through anaperture1006 on the flexibleouter casing tube1004 and then is passed outwardly through the end of thetubing1008 as shown in FIG. 50.
• Referring to FIG. 51, the[0233]electrode1000 is then assembled over the end oftube1004 over a tapered portion as shown in FIG. 51.
• The end of the[0234]tube1004 received overtube1008 is then clamped and secured thereon bysuitable clamping fixtures1010,1012 as shown in FIG. 52. Thetube1004 is then stretched such that theelectrode1000 may be passed thereover and located overaperture1006 with thelead1002 being fed through the end oftubing1008. It will be understood that the stretching or pulling oftube1004 as indicated by the arrow in FIG. 52 causes a reduction in diameter of thetube1004 which permits theelectrode1000 to be slipped thereover and be positioned over theaperture1006. When theelectrode1000 is located at the desired position over theaperture1006, theelectrical lead1002 is pulled through the end of thetube1008 as shown in FIG. 53. When theelectrode1000 has been positioned at the desired position the pulling force on thetubing1004 is then released, thetubing1004 expands to engage the interior of theannular electrode1000 and maintains theelectrode1000 in a desired position on thetube1004. The clamping load ofmembers1010,1012 are then released; the excess material on the end oftube1004 is then removed as shown in FIG. 54.
• Referring to FIG. 55, a schematic view of the temperature control of the distal electrode of the[0235]ablation catheter600 of FIG. 40 is illustrated in a standard feedback control flow-chart.
• Referring to FIG. 31, all electrodes disposed on the distal portion of the catheter of this invention may be formed of electrically conductive elastomeric material(s)[0236]
• Although the present invention has been described hereinabove with respect to the illustrated embodiments, it will be understood that the invention is capable of modification and variation and is limited only by the scope of the following claims.[0237]

Claims (40)

What is claimed:

1) An electrophysiology/ablation catheter comprising:

a) an elongated flexible hollow tubular casing having a proximal end and distal end and a plurality of spaced electrodes disposed at the distal end thereof,

b) a pair of flexible tension/compression members disposed in side by side relationship and extending in the hollow of said casing from a point of attachment adjacent said distal end to said proximal end of said tubular casing;

c) an electrical lead connected to each of said electrodes and extending through the hollow of said tubular casing to the proximal end thereof, said lead adapted for external connections thereto;

d) spacer means disposed between said pair of flexible tension/compression members at said distal end for maintaining lateral spacing between said members, said spacer means being flexible; and,

e wherein longitudinal tensioning of a first of said tension/compression members and simultaneously longitudinal compressing of the second of said tension/compression members with respect to said casing effects lateral displacement of said distal end of said casing in one direction and longitudinal tensioning of the said second of tension/compression members and simultaneously longitudinal compressing of the said first of said tension/compression members with respect to said casing effects lateral displacement of said distal end of said casing in a direction opposite said one direction.

2) The catheter defined inclaim 1, wherein said pair of tension/compression members each have a portion thereof adjacent said distal end formed to have a flattened transverse section.

3) The catheter defined inclaim 1, wherein said spacer means comprises a blade spring member.

4) The catheter defined inclaim 1, wherein said spacer means comprises a wave shaped spring member.

5) The catheter defined inclaim 1, wherein each of said tension/compression members has substantially rectangular transverse section in the region adjacent said distal portion with the balance thereof having a generally circular cross-section.

6) The catheter defined inclaim 1, further comprising an elongated flexible tubular guide member disposed in said casing, said guide member having a pair of spaced parallel lumens formed therein with one of said pair of tension/compression members disposed in each lumen.

7) The catheter defined inclaim 1, further comprising a sleeve received over said flattened portion of said tension/compression members and spaced a preselected distanced from said distal end, said tension/compression members secured therein and forming a kinematic junction at said sleeve, wherein the portion of said tubular casing distal said sleeve remains substantially un-deformed upon simultaneous tensioning and compressing of said tension/compression members.

8) The catheter defined inclaim 7, wherein said spacer means has an end thereof secured in said sleeve with the other end of said spacer floating in the space between said tension/compression members.

9) The catheter defined inclaim 1, further comprising an elongated flexible tubular guide member disposed in said casing with said tension/compression members received therethrough; and, a rigid collar attached to the distal end of said guide member and extending over a portion of said tension/compression members having said spacer means therebetween.

10) The catheter defined inclaim 9, wherein said rigid collar has a flatted cross-section on one end and a generally circular cross-section on an end opposite said one end.

11) The catheter defined inclaim 1, further comprising an annular reference electrode disposed on said tubular casing at a station therealong remote from said plurality of spaced electrodes, wherein said reference electrode is located such that it remains exterior to the heart cavity upon insertion of the said plurality of spaced electrodes into a heart cavity.

12) A method of making an electrophysiology/ablation catheter comprising:

a) disposing at least one electrode on a distal portion of an elongated flexible tubular member and connecting an electrode lead to said electrode and extending said electrode lead to a proximal end of said tubular member;

b) disposing a pair of elongated tension/compression members in said tubular member and fixing an end of each of said pair in the distal portion of said tubular member and extending said pair to the proximal end of said tubular member;

c) disposing a flexible spacer intermediate said tension/compression members in the region of the distal portion thereof and spacing said tension/compression members laterally;

d) disposing an actuator movably on a handle and connecting said handle to the proximal end of said tubular member; and,

e) connecting said actuator to the proximal ends of said tension/compression members.

13) The method defined inclaim 12, wherein said of fixing includes securing by weldment.

14) The method defined inclaim 12, wherein said step of disposing a flexible spacer includes securing an end of said spacer to said tension/compression members by weldment.

15) The method defined inclaim 12, wherein said step of disposing a flexible spacer includes flattening a portion of the distal end of said tension/compression members and securing an end of said spacer thereto by weldment.

16) The method defined inclaim 12, further comprising disposing a sleeve over said tension/compression members and positioning said sleeve a preselected distance from said distal end and securing said sleeve to said tension/compression members and forming a kinematic junction thereof at said sleeve

17) The method defined inclaim 12, wherein said fixing includes disposing an additional flexible tube within said casing a certain distance from said distal end and partially stiffening a portion of said tubular member.

18) A method of installing a distal electrode to an electrophysiology/ablation catheter comprising:

a) providing a generally cup-shaped member of electrically conductive material and forming a plurality of spaced fingers extending axially from the rim of said cup-shaped member;

b) disposing the open end of said cup-shaped member over an end of a tubular catheter casing member and deforming said fingers radially inwardly and passing at least one said fingers through the wall of said tubular member and securing said cup-shaped member to said tubular member with said finger; and,

c) attaching an electrical lead to said at least one finger and extending said lead through said tubular member.

19) The method defined inclaim 18, wherein said step of securing includes further deforming said fingers and extending said at least one finger along the inner surface of said tubular member.

20) The method defined inclaim 18, wherein each step of securing includes further deforming said at least one finger to fold back on itself along the inner surface of the said tubular member.

21) The method defined inclaim 18, wherein said step of passing said at least one finger through said tubular member includes piercing said wall with said at least one finger.

22) A motorized electrophysiology/ablation catheter actuating assembly comprising:

a) an elongated flexible tubular member having a distal end and a proximal end and having a pair of tension/compression members disposed therein and kinematically joined in said distal end, said tension/compression members extending through the proximal end of said tubular member;

b) hollow handle structure attached to the proximal end of said tubular member, said handle structure having therein a motor drive including means for connecting motor rotation to linear movement with the proximal ends of said tension/compression members connected to said means for connecting,

c) a source of electrical power disposed in said handle structure and user operated switch means disposed on said handle structure for energizing said motor drive, wherein said motor drive is operative, upon being energized for rotation in one direction, to cause said means for converting rotation to simultaneously pull and push said first and second tension/compression members respectively and effect curvature of said tubular member in one direction; and said motor drive is operative, upon being energized for rotation in a direction opposite said one direction to cause said means for converting rotation to simultaneously pull and push said second and first tension/compression members respectively and effect curvature of said tubular member in the opposite direction.

23) The assembly defined inclaim 22, wherein said handle structure includes a position sensor for sensing the position of a member of said means for converting motor rotation to linear motion as an indication of the radius of curvature of the distal portion of said tubular member.

24) The assembly defined inclaim 22, wherein said handle structure includes connector means adapted for external electrical connection; and, said tubular member includes lead means connected to at least one distal electrode, said lead means having the proximal end thereof connected to said connector means.

25) The assembly defined inclaim 22, wherein said connector means includes connections for remote control of said motor drive.

26) The catheter defined inclaim 1 further comprising a solid state temperature sensor disposed in said distal electrode and sensing lead means connected to said sensor, said sensing leads means extending through said casing to the proximal end thereof for connection to a sensing circuit.

27) The catheter defined inclaim 1 further comprising a fiber optic temperature sensor received through said casing, having an end thereof connected to said distal electrode for conducting a temperature sensing signals to the proximal end thereof.

28) The catheter defined inclaim 1 further comprising:

a) heating element disposed in said distal electrode;

b) electrical supply lead means connected to said distal electrode, said supply lead means extending through said casing to the proximal end thereof wherein upon powering said lead means, said distal electrode is heated.

c) electric power supply and temperature control module disposed in said handle to control the temperature of said distal electrode for ablation procedures.

29) The catheter defined inclaim 28 further comprising a solid state temperature sensor disposed in said distal electrode and sensing lead means connected to said sensor, said sensing leads means extending through said casing to the proximal end thereof for connection to a sensing circuit disposed in said handle.

30) The catheter defined inclaim 1, wherein said distal portion of said tension/compression members are received in a flexible guide tube disposed within said casing, said guide tube having an end engaging said distal electrode.

31) The catheter defined inclaim 28, wherein said flexible guide tube has a pair of internal septum formed therein extending the length thereof for separating said tension/compression members and said spacer means

32) The catheter defined inclaim 1, wherein the proximal end of each of said tension/compression members is received in a closely fitting metal tube; and, said metal tube is deformed by clamping and said tube and tension/compression member are secured to a reciprocating member operationally connected to said actuator member.

33) The catheter defined inclaim 1, wherein said handle includes a pair of reciprocating members operationally connected to said actuator member, with each reciprocating member connected to one of said tension/compression members; and, said handle includes a displacement sensor operative to sense the motion of at least one of said reciprocating members.

34) The catheter defined inclaim 1, wherein said handle includes means operable for frictionally securing said actuator in a user selected position.

35) The catheter ofclaim 34, wherein said means for frictionally securing includes an elastic rubber.

36) The catheter defined inclaim 32, wherein said means for frictionally securing includes a spring loaded plunger.

37) The catheter defined inclaim 1 further comprising an elastic collar received over the proximal end of said casing, said collar operable to grip said casing upon user grasping thereof for enabling the user to readily apply torque to said casing.

38) The catheter defined inclaim 37, wherein said collar is axially moveable along said casing for permitting user selection of the region of torque application therealong.

39) A method of installing an annular electrode on a flexible catheter casing comprising:

a) attaching an end of an electrical lead to said electrode;

b) forming an aperture in said casing and passing the remote end of said lead through said aperture;

c) securing the proximal end of the casing over a rigid tube;

d) stretching said casing axially, necking said casing and sliding said electrode over said casing and positioning said electrode over said aperture with said lead therethrough;

e) releasing said stretching to expand said necking and securing said electrode on said casing; and,

f) removing excess casing material.

40) The catheter defined inclaim 1, wherein said distal electrode and said plurality of spaced annular electrodes are made from electrically conductive rubber-like material.

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