CA2061219A1

CA2061219A1 - Endocardial mapping and ablation system and catheter probe and method

Info

Publication number: CA2061219A1
Application number: CA002061219A
Authority: CA
Inventors: Mir A. Imran
Original assignee: Mir A. Imran; Cardiac Pathways Corporation
Current assignee: Cardiac Pathways Corp
Priority date: 1991-02-15
Filing date: 1992-02-14
Publication date: 1992-08-16
Also published as: AU1088992A; EP0771547A2; JPH07178113A; US5156151A; EP0499491A2; US5279299A; US5404638A; US5406946A; EP0771547A3; EP0499491A3; AU662119B2

Abstract

ABSTRACT
Endocardial mapping and/or ablation system for introduction into a chamber of the heart formed by a wall by passage through a lumen leading to the chamber in the heart having blood therein comprising a cathater probe with proximal and distal extremities and having an elongate tubular member with at least one lumen extending therethrough extending the length thereof and with a distal extremity. A plurality of longitudinally and radially spaced apart electrodes are provided. An expandible device is secured to the distal extremity of the flexible elongate tubular member and is movable between a contracted position and an expanded position.
The electrodes are mounted on the expandable device whereby when the expandable device is moved to the expanded position in a chamber of the heart the electrodes are moved into engagement with the wall forming the chamber of the heart in which the expandable device is disposed. An elongate element is coupled to the expandable device for moving the expandable device between the contracted and expanded positions. The expandable device has spaces therein through which the blood can flow when the expandable device is in an expanded position.
Leads are in contact with the electrodes and extending through the flexible elongate tubular member. Electrical apparatus is connected to the leads for performing electrical functions with respect to the electrodes.

Description

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ENDOCARDIAL~A~P~P~NG AND AB~A'rION SYSTEM ~ND CATHETER
DE~lh~ ' Thi6 invention relates to ~n e~docardial mapping ~nd ablation system and c~th~ter probe and method.
Endocardial mapping and ablation cathet~xs have heretofore been provided. However, they have been o~ limited capability particularly because they only have very few electrodes which makes it di~icult to map accurately the electrical potentials in the walls ~orming the chambers of the heart, ~s for example, the right ventricle. In order to obtain information from several di~erent ~ites, it has been n~cessary to maneuver ~he di6tal extremity of the catheter ext~nsively and to repo~ition it radially incr~m~ntally in the chamber o~ the heart. Such a procedure 2~ has been ~ound to be time consuming and relatively inaccurat~. There is therefore a need ~or a new and improved endocardial ~apping and ablation ~ystem and a me~hod for accomplishing the ~ame.
In general it iB an object o~ the present invention ~o provide an endocardial mapping and abla~ion ~y~em and a method which u~ilizes a large number o~ electrodes ~aking it possible to perform endvcardial mapping accura~ely ~nd rapidly.

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~ .f~ 3 Another object o~ the invention is to provide a system and method of the above charac~er in which ablation can be precisely carried out.
Another object of the inve:n~ion i~ to provide a system 5and method of the above character in which bipolar electrode pairs are utilized.
Another object of the inve:ntion is to provide a system and method of the above character in which a plurality of radially and longitudinally ~pa.ced elec rodes are ~rovided 10which make possible simultaneous measuremenks through 6ubstantially 360 of a wall forming a chamber in the heart.
Another objeck of the invention i~ to provide a system and method of the above character in which the Qlectrodes are expanded into engageInent with the wall o~ the chamber lSof the heart ~nd are maintained in engagement with that wall during pumping action of the heart.
Another object o~ the invention i~ to provide a ~ystem and method in which the ~lectrodes are yieldably retained in eny~gement with the wall ~orming the chamber o~ the heart 20during the ti~e that the heart i6 expanding and contract~ng the chamber.
Another object of the invention is to provide a ~ystem and method of the ~bo~e character in which a catheter probe is utilized having an expandabl~ distal extremity and in 25which the distal extremity of the catheter probe is adapted to be dispos~d in the chamber of the heart.
Another object of the inventi~n i5 to pr~vide a system and method of the above character in which the presence of the distal extremity o~ the probe in the heart does not 30substantially imped~ the ~low of blood in the ~hamb~r of the heart.
Another objec o~ the invention i~ ~o provide a ~y~tem ~nd method o~ the above character in which the mapping ~nd ablation proceduxes can be carried out without m~vement of 35~he di~tal extr mity of the catheter probe wi~h respect to the wall forming the chamber ~ the heart.
Additi~nal objects and ~eatures of the inven~ion will appear ~romthe followlng description in which thepr@~erred , `:
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embodiment is set ~orth in detail in c~njunction with the accompanying drawings.
FIGURE 1 is a schematic illustration of an endocardial mapping and ablation system andc:atheterprobe incorporating the pxesent invention.
~IGURE 2 is an enlarged plan view showing in particular th~ flexible ~heet used to form the cylindrical member at the di~tal extremity of the c~theter probe shown ln Figure 1.
FIGURE 3 is an enlarged detail view of a portion Or one of the arms of the cyllndrical member showing the ~pring metal strip used in the arm.
FIGURE 4 is an enlarged cro~s sectional view taken along the line 4-4 of Figure 2.
FIGURE 5 is an enlarged cross-sect~onal view taken along khe line 5-5 of Figure 2.
FIGURE 6 is an enlarged detail view partially in cross section o~ the distal extremity of the c~theter probe.
FIGURE 7 is a cross-sectional view taken along the line 7-7 of Figure 2.
~IGU~E 8 i~ an enlarged ~ross-6ectional view taXen along the line 8-8 of Figure 2.
FIGURE g $~ a ~ro~s-~ectional view taken alony the line 9-9 ~ Figure 2.
~IGURE 10 is a schematic dia~ram of the electronic circuitry utilized in the system for performing the meth~d of the pressnt invention.
FIGURE 11 is a cross-~ectional view of the heart 6how$ng the manner in which the 6ystem ~nd catheter probe of the present invention are employed in the right ventricle to achieve mapping and/or ablation in ~ccordanc~ with the method o~ the present invention.
~IGURE 12 is a cro~s-~ctional ~iew *aken al~ng the line 12-12 o:E Figure 11.
~IGURE :L3 is a timing diagram for the circuitry shown in Figure 10.
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FIGURE 14 is a partial view o:f another ~heet incorporating the present invention for use wikh a catheter pr~be which shows a plurality of chips carried thereby.
FIGURE 15 is a cross sectit~nal view of a catheter probe showing the manner in which the plurality o~ chips ~hown in Figure 14 arP radially disposed about a mandrP1 ~or the catheter probe.
FIGURE 16 i~ a partial plan ~iew Qf another catheter probe incorporating the present invention and for 115e with the sy~tem and method of the present invention.
FIGURE 17 is a cross 6ectional view taken along the line 17-17 of Figure 16.
~IGURE 18 is a cross sectional view taken along ~he line 18-18 of Figure 17.
FIGURE 19 is a partial elevational view showing the catheter probe of Figure 16 with the expandable means in an expanded position.
FIGURE 20 is a cross~sectional view taken along the line 20-20 of Fiqure 19.
FIGURE 21 is a plan vlew of an a7ternative bipolar electrode ~or use with the present in~ention.
In general, the endocardial~apping and ablationsys~em ~f the present invention is utilized for lntroduction into a ch~mber o th heart ~ormad by a wall of the he rt. It consists o~ a catheter having proximal ~nd distal ~xtremitie~. The c~theter probe is compri6ed of ~ ~lexible elongate tubular member having at least on~ lumen th~r~in extending the length thereof and having proximal and distal extremitie~. ~ plurality of longitudi~ally and radi~lly spaced apart electrodes are provided. Expandabl~ means i6 6ecured to the distal extremity of the ~lexible elonga~e tubular member and i movable between a c~ntracted position and an expanded position. Means i6 proYided for m~unting the electrocles on the expandable means whereby when the expandable ~leans is moved to the expanded positi~n in a chamber in the heart, the eleckro~es ar~ moved into . , _5_ r~

engagement with the wall forming the chamber o~ the heart in which the expandable means is disposed. M~ans is ooupled to the ~xpandable means :Eor moving the expandable means between ~aid contracte~ and expanded positions. The expandable means has open 6paces between the ~aIn~ GO as to permit the ~low oP blood through the spaces when in the e~panded position. Leads are pr4vided which are in contact with the electrodes and extend into the ~lexible elongate tubular m mber to the proximal extremitie~ thereof.
Electrical means i5 provided which is connec~ed to the leads ~orperforming mapping andablation andprogramed el~ctrlcal stimulation ~uncti~ns in con~unction with said electrodes.
More in particular, the endocardial mapping and ablation ~ystem 21 as shown in the drawinys consist~ of a catheter probe 22 which is provided with a high voltage connector 23 and 2 eignal connector 24 that ar~ co~nected to mating connectors 26 and 27 ~orming a part of a cable 2~. Cable 28 is connected to a catheter interface m~dule 29 which supplies and receives appropriate ~ignal6 to and from a computer 31 that i5 provided with a disc drive 32 and a monitor 33O It is als~ provided with a keyboard tno~ shown) for use in csntrolling the operation o~ the computer.
The catheter probe 22 consists o~ a flexible elongat~
tubular mem~er 36 form~d ~ a suitable material such as plastic which is circular in cross ~ction as shown in Figure 7. The tubular member 36 has a suitable diameter as for example 0.10" to .150" and a suitable length as for example from lO0 to 150 cm. ~he tubular member 36 is pro~ided wi~h proximal ~nd distal extremities 37 and 38 and is pravided 3~ with at least one lumen and as shown in Figure 9 iæ provid~d with three lumens 39, ~l and 42 in which lumen 39 is a centrally disposed lumen and lumen 41 and ~2 are two generally crescent shaped lumens provided on opposi~e sides of the lumen 39. Both lumens 39 and 41 ex~end ~rom the 3~ proximal extremity 37 t~ the distal extremity 38 of the tubular membler 36.

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A ~lsxible expandable cylindrical mel~er 46 ls secured in a fixed position to the distal extrsmity of the flexible elonyate tubular member 36. The ~xpandable cylindrical member 4~ is movable be~w~n contracted and expanded positions as hereina~ter described. The expandable cylindrical member ls provided with a plurality of circumferenti~lly ~paced apart longitudinally extending flexible ~rms 47 having adjoined proximal and di~tal extremities or end porti~ns 48 and 49 (see ~igur~ 6).
The flexibleexpandable cy.lindrical member46is ~ormed from a flexible flat ~heet 51 (~ee Figure 2~ which i5 in the form of an elongate rectanglP having sideways extending ears 52 and 53 on oppocit~ ends. ~he ~heet 51 1~ formed of a suitable insulating ~a~erial ~uch as plastic. one plastic found partlcularly suitable is ~ polyimide identi~ied as Kapton (trademarX). Assuming that the plurality of arms 47 to be utilized in the cyli.ndrical member 46 i5 eight, the ~heet 51 ~6 61ittçd with a Xnie or die (not 6hown~ to provide parallel spaced apart slits 56 extending longitudinally between the ears 52 and 53 to ~orm the plurality o~ circum~erenti~lly ~paced l~ngitu~inally extending arms 47. Small hol~s 57 are provided on thP
~pposi~e ends o~ each of the sli~s 56 and serve to prevent propagation o~ the 56 slit6 into th~ proximal and distal extremities or end p~rtions 48 and 49 of the sheet 51.
In order to impart springiness to the arms, the ~heet 51 can be formed of two plastic ~heet~ bonded together over die cut metal strips 61 of a ~uitable material such as stainless steel or pla~tic having naxrowed p~rti~ns 61a lsee Figure 3~ ~o that the metal strips 61 are ~mbedded between the two layers 62 and 63 o~ pla~tic ~see Figure 4) and encapsulated therein so that they lie in the are~s between the lines in which the ælits 56 are to ~e cut. In c~rtain applications ~ th~ present invention, it may be desir~ble t~ form the strips 61 with a particular pattern to achieve a desired conformation for the b~wing out of ~rms 47 of ~7~ ~ r~

the expandable cylindrical member 46 when it i5 expandecl as hereina~ter descri~ed. The narrowed portion ~la can be provided at the proximal extremity to achieve greaterbowing o~ the arm 47 in that region a~; the cylindrical member ~6 is expanded as hereinafter de~cribed. The stainless steel ~trips can have a desired width, as ~or example, less than the width of the arms 47 and can have a ~uitable thickne~s as for example 0.001" to 0.010" in thickness and the plastic layers 62 and 63 ~an have a ~uit:able thickness ranging ~rom 0.001" to 0.010" in thickness and typically a thickness o~
.002".~
Radiallv spaced apart rectanyular radiopaque markers ~4 ~ormed o~ a suitable material ~uch ~s lead or platinum can be positioned 50 that they underlie the 6tainles~ eteel ~trips 61 ~nd are embsdded between the layers 62 and 63 o~
the layers ~2, 63 and 64 fc)rming the ~heet 51. As ~hown in Figure 2, the markers 65 are ~taggered in di~tance from the distal extremity 60 that they form a portion ~f a helix when the 6heet 51 i8 ~c~rmed into the cylindrical member 46 as hereinafter deacribed. The marker~ 65 ~re only placed on certain ~f the arms 47 as for example ~ive o~ the eight arms ~hown in Figure 2~ This aids in ascertaining the rotational position o~ the m~mber 46 under fl~uroscopy as hereinafter described.
2~ A plurality o~longitudinally and radially spaced apart tets 66 ~f bipolar ele~trodes 67 ~nd 6 are provided on the exteri~r sur~aces 69 of the ar~s 47which ~erve a~ insulating substrates and are ~paced laterally of ~heet 51 ~see Figure 6~ and circumferentially around the cylindrical mamber 46 (~ee Figure 6). The cylindrical member 46 ~erves as an expandable means 6ecured to the distal ~xtremity of the tubular eloncJate element 36 and is movable between contracted and ~xpanded positi~ns whereby when the expanda~le means is moved to the expanded position the electrodes 67 ~nd 68 are brought into engagement with the wall o~ the heart A-54132/HC'H

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fDrming the cha~ber in which the expandable means is di~posed as hereinafter described.
The electrodes 67 and 6~ as shown are rectangular in ~hape and can have a length of 0.040" and a width o~ 0~040".
The bipolar electrodes 67 and 68 can be separated by a 6uitable distance as ~or example 0.040". I~ desirad the electrodes 67 and 68 can be o~ dif~eren~ GiZes. heads 71 are provided on ~he interior or lnner ~ur~aces 72 o~ ~he arms 47. The electrodes 67 and 68 and the leads 71 are ~ormed o a uitable conductive material~. The outer or exterior 6urfaces 69 ~nd the inner or interior ~urPace~ 72 of the arm 47 of ~heet or substrate 51 a~e coated with vapor d~po~ited or electroplated layer o~ a ~uitablo conductive metal such ~ copper to provide a copper layer 73 of ~
6uitable thickness a6 ~or example o . 0005". Th~ ~heet 51 is then drilled to ~orm holes 74 extending betw~en the copper layers 73. Additional conductive materi~l ~uch as copper is then plated throu~h the holes 74 to ~orm the vias 76 (see Figure 5). Thereafter, conventional etching techniques are used to remove the und~sired copper material on the outer surfaces 69 and on ~he inner surfac2s 72 o khe arms ~7 so that there remains longitudinally ~paced apart electrodes 67 and 68 on the ou~er eur~ace 69 and la~erally spaced ap~rt longitudinally ex~ending leads 71 which are conn~cted ~o the sets ~6 o~ electrodes 67 and 68 by the vias 76. Each o~ the electrodes 67 and 68 is connected to one of the leads 71 by a via 76. The leads 71 are insula~d from the metal strips 61 by the plastic layer ~3.
The electrodes ~7 and 68 as well as ~he l@ad~ 71 can be augmen~ea by pla~ing onto the copper layer 73. Thus, a~ shown in Figure 5, the electrode 67 can be augment~d by depositing ~ nickel layer 77 on the copper layer 73 ~ollowed by a gold layer 7~ deposited on the nickel layer 770 ~old is particularly suitable as a final layer in ~his application because it is inactive in blood. It also is an excellent conductor.

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The proximal end of the sheet 51 shown in Figure 2 is provided with an extension 81. A multiplexer chip 86 of the type hereina~ter descri~ed is mounted on or attached t~ extension 81 by conventional bonding techniques and is connected by conventi~nal techniques to the leads 74 connected to the electrodes 67 and 68.
In forming the sheet 51 of Figure 2 into the cylindrical member 46, a distal mandrel 9~. and a proximal ~andrel 92 are utllize~. The di~tal mandr,el 91 i6 cyllndr~cal in rOrm and can be ~ormed of a sultable material ~uch ~s pl~stic ~r metal. ~he di6tal mandrel 91 ie provlde~ wlth ~ ~entrally disposed hole 93 which i5 provided wlth an outwardly ~lared portion 93a. The proximal mandrel 92 i~ alco formed o~ a suitable material such as plastic ~nd i~ provided with a cup-like recess 96 (see Figure 6). Ik ~ al60 provided with a hole 97 which curves slightly downwardly to clear the receæs 96 and extends through the mandrel 92. An additional hole 98 i~ provided in the mandrel 92 which opens into recess 96.
The shee~ 51 is wrapped into a cylinder with the ears 52 overlapping the ears 53 by inserting the ears 52 through T-shaped slots 99 formed in the ear~ 53 and having pairs of ~paced-apart sIits 101 mating with the slots 99 so that the outer sid~ margins of the ~heet 51 are brought together 2~ ~o ~orm another 81i~ 56 between the two adjacent arm~ 47.
The ears 52 and 53 also can bP overlapped and fastened ~ogether on them elves by suitable means such as an adhesive.
When fabricated in this manner, the cylindrical ~e~er 45 typically would have a diameter of approximately 0.150~' and a 6ui~abl~ length as ~or ~xample 2 1/2" depending upon the size of the cavity in the heart to be mapped.
During wrapping o~ the ears 52 and 53 around the mandrel 91, the extension 81 and the chip 86 thereon ic positioned within the cup- shaped recess 96. An encased cry~tal 102 is also mounted in the reces~ 96 ~verlying the chip 86. An RC oscillat~r (not shown) on the chip 86, may be used in place of crystal 102. ~he recae6 96 1~ enclosed by 6emi-cylindrical cover 103. Prior to the placement of the cover 103, the chip 86 and the crystal 102 may be encapsulated in a suitable epoxy 104 placed in recess 96. The epoxy 104 can have heat sinking capabilities to disslpate any heat generated within the chip 8 6 .
An al~ernative ~mbodiment f`or th~3 mounti:ng of the multiplexer chip ~6 is ~hown in Fi~ures 14 and 15. Ag shown ther~in, the multiplexer chip ~6 instead of being in only a single package as ~h~wn in Figures 2 ~nd 6 can have it6 circuitry ~s well ~s other circuitry 6upplied in a plurality of chips, as ~or example, chips 86a, 8~b and 86c which are mounted on the shee~ 51 on the proximal end portion 49 i~mediately adjoining the ear6 52 and the proximal 1~ extremities of the arms 47 so that the leads carried by the arms and connected to tha electrodes 67 And 68 c~n be connected directly to the chips 86a, 86b and 86c. Chips 86a, 86b and 86c are spacPd apart a suitable distance so that when the sheet 51 i~ wrapped about the proximal mandrel 92a ~hown in Figure lS, the chips 86a, 86b and 86c are received within circumferentially spaced apart recesses 96a, 96b and 96c provided in the proximal mandrel 02a. Such an arran~ement has an advantage in that it makes it possible to provide additional circuitry i~ d~sired in the flexible elongate me~ber 36 in close proximity to the electrodes 67 and ~8. Also it permits the hole 97a (Gee Figure 15) to be centrally dispo6ed in the proximal mandr~l 92a ~o that the pull wire 116 (here~n~fter described) extending therethrou~h can extend along the cen~er axi6 of the mandrel 92 rath~r than beiny ~ et as shown in ~igure 6.
A band 106 ~ormed of a ~uitable conducti~g mekal such as g~ld is provided ~t the di~tal extremity of the cylindrical:memb~r 46 over the mandrel ~1 ~nd ~erve~ a~ a ground. Alternatively, a large surface area electrode may 3~ be placed on the chest o~ the patient (not shown) t~ ~erve ~s a ground for the ablation current. A tubular sleeve 105 .

r ~ q ~r3 is ~itted over the proximal mandrel g2 and extends over thP
proximal extremity o~ the cylindrlcal member 46. The ~le~ve 103 can be ~ormed of a suitable material such as injection molded plastic. I~ can be fo~ned as a separate sleeve or can be ~ormed integral with the ~lexible elonyate tubular member 36 forming the probe catheter 22 to provide a one-piece construction.
Wlth respect to the embod:Lment ~hown in Figures 1-9, the tubular member 36 i~ rotat:lonally aligned 50 that its central lumen 39 is in alignment wlth the hole 98 in the proximal mandrel 92. Beaause of the multiplexing capabilities of khe chip 86 a relakively small number o~
wires or conductors 108 are connected to the chip 86. For example, as few as sev~n insulated conductors 10~ can be provided which are bonded to pads (not shown) conn~cted to the chip 86. The conductors 108 extend through the hole 98 and into the crescent-shaped lumens 41 and 47 provided in the flexible elongate member 36. The conductors 108 extend through thP ~lexible elongate cylindrical member 36 and are connected to the connectors 23 and 24 heretofore described.
Seven conductors 108 would be provided when bipolar mapping and ablation is de~ired. Rather than using a ~ingle connector for all ~f the wires or c~nduct~rs 108, it i8 desirable to ~eparate the conductors into a high voltage set of conductors and a ~ignal set ~f conductors. ~hus, with seven conduc~or~, the four conductor6 ~ssociated with high voltags can be connect~d into the quadrapole ronn~ct~r 23 and th~ thr~e wires o~ the Gignal s~t can bP connected into a triaxial c~nnector 24.
Anoth~r tubular mem~er 111 i~ connected to the proximal extremity 37 of the tubular memher 36 and is provide~ with a lumen 112 which i~ in regi~trati~n with the central lumen 39 pr~vided in the tubular member 36. An elongate pull wire 116 is disp~sed in the lumens 112 and 39 and is ~ormed of a suitable material such as s~ainless steel and can have -12~ 7,t.~q ~

a size as ~or example .01~" ln ~iameter. The pull wlre 116 Pxtends ~he l~ngth o~ the tubular member 36 and extends in~o the lumen 97 provided in the p:roximal mandrel 92 and then into the int~rior of the flexible ~xpandable cylindrical member 46 which also may be called a cylindrical expandable ~lectrode array and through the hole 9~ provided in the distal mandrel 91. A~ter ~he pull wire or ele~ent 116 has been inserted into the ~atheker and through the hol~ 93 o~
the mandr~l 91, the distal ext:remity of the pull wlre or element 116 ls pr~vided w~th an enlarged portion 116a which can be formed integral with the pull wlre or element 116 or can be ~o~med as a ~ep~rat~ part bonded ko the distal extremity o~ the pull wire. The p~rtion 116a has a size which i~ 6ufficiently yreat 80 that it cannot be pullod through the hole 93 but which is ~till ~mall enough to eeat within the flared portion s3a o~ the hole 93 and not protrude substantially beyond the distal extremity of the mandrel 91. The pull wire 116 is provided wlth a knob 117 on its proximal extremity for ~peration of the pull wire.
Operation and use of the catheter or pro~e 22 in connection with the catheter interface ~odule 29 and the computer 31 o~ the system 21 may now be briefly described as follows in u~ilizing thepr~ent invQntion. The catheter probe 22 is ~irst used with the cylindrical expandable member or electrode array 46 in its normal contracted position which can be ensured by pushing on the knob 117 to fully extend the pull wir~ 116 to ~x~end beyond the mandrel 91 eo that it can ~erve as guide wire. The catheter or probe 22 is inserted into a cavity 131 o~ the heart 132 ~Fi~ure 11) as for example the right ventricle o~ the heart in a human body by access through ~ fem~ral v~in. Thi~ can be accompli~hed in a conventional mann~r by introducing the guide wire or pull wire or element 116 and thereafter the distal extremity of the ca heter pr~be 22 into the femoral vein by the use of a guide ~heath and/or a guiding catheter. This can be done in a conventional manner l~nder ~luoro~copy in which A-54132/HC~H

the catheter or probe 22 can be introduced through the superior inferior vena ~ava into the right atrium and then advanced into the right ventricle as shown partioularly in Figures 11 and 12. In connection with this procPdure, the pull wire 116 can bP utilized as a guide wire and can be rotated by xo~ating the knob 117 to Pacilitate advancing the catheter through the desired 2ath into the v~ssel lumen leading to the heart.
As Boon as th~ distal extremit~ of the catheter probe 22 ls po~i~ioned within the desired cavity o~ the heart a~
for example the righ~ ventricle 131 o~ A heart 132 as ahown in Figure 11, connectors 23 and 24 can be interconnected with th~ mating conneators 26 and 27 ~o that the cathet~r probe 22 i5 connected to the ~atheter inte.r~a~e module 29 and the computer 31. Once thi6 has been ~ccomplished, the pull knob 117 can be retracted ~o move the p~rtion 116a o~
the pull wire into the recess 93a and upon ~urther pulling movement to cause expansion o~ the cylindrical expandable member or electrode array 46 to cause lts arms 47 to be bowed outwardly as ~hown in Figure 11 wit~ the distal extremity . or tip of the cylindrical electrode array 46 touching the distal extremity or apex o~ the right ventricle 131 so that th~ arms and the ~lectr~des 67 and 68 carried thereby are brought into contact with the wall o~ the heart forming the 2~ right ventricle. As shown in Figure 11, the bowing o~ the rms ~7 ~s m~re pronounced at the proximal extxemity 48 and at the distal extremity 4g of each of the ~rm 47. This increased bowing is made possible by providing the narrowed portions 61a on the proximal and ~istal extremiti~s of the metal ~trips 61 as hereinbe~ore described. The flexibility of the arm~ 47 permit6 the heart to continue it~ normal beatiny patt:ern in m~ving the wall formin~ ~he right ventricle 131 inwardly and outw~rdly. At the ~ame time because the arms 47 ~re spread or spaced apart ~s they are bowed outwardly, there i6 ample space between the arms so that normal blood flow in the right ~entricle 131 can occur ~ubstantially un~mpeded by the electrode array 46 when th~
array 46 i~ in the chal~er, The springiness o~ the arms 47 i6 such that the ~rms 47 wiLl yieldably ~ollow the muscular contractions and expan6ions o~ the right ventricle and keep the bipolar electrodee 67 and 6~ in ~ubstantially continuous contact with the heart wall and the electri~al circuitry provided in the hsart wall. It should be ~ppreoiated that similar procedures can be u6~d ~or po~itioning the catheter probe 22 in other chamher6 o~ the heart as ~or example the le~t ventricle o~ the heart.
In the embodiment ~hown :Ln Figures 1-13, eight arms 47 are provided with six sets of electrode pairs with ~our of the arms having an additional sets of each end each ~or a total o~ 112 electrodes and ~6 electrode pairs. Fewer bipolar pairs are provided at the ends because the arms 47 are closer together at the ends when the cyllndrical expandable member 46 i6 expanded. Each ~ipolar electrode pair is connected to a dif~erential amplifier 141 ~ee Figure 10). Each of the differential ampli~iers 141 is provided with input circuitry 142 which c~n~ists o~ current limiting resistors Rl and R7 connected to diodes Dl and D2 on opposite ~ides o~ the input line with the diode D2 being connected t~ ground and di~de Dl being c~nnected to a positiv~ voltage. Diodes D3 and D4 are connected to ~h~
other input line with diode D4 being connected to ground and diode D3 being connected to the positive voltage. These ~erially connscted diod~s ~erve to protect the inputs to th~ mpli~ier~ 141 during the time that abl~ttion voltages ~re being applied as hereira~ter de~oribed. Th~ ~nput circuitry has the capability o~ limiting the voltage ri~e at the inputs ~f the ampli~i~r 141 to ~pproximately 1/2 volt.
The dif~ere~tial amplifiers 141 have a uitable gain ~6 ~or example typically between 100 and 500. Since th~ ~nd~cardial 6ignals that ~re received ~rom t~e heart ~re of relatively 3~ high amplittlde, a very high gain i~ not required rom ~he amplifier~ :L41.

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-15~ ,3 The outputs of the ampli~iers 141 are connected by ~6 lines 142 ~ls~ the ~ultiplexer 146 identified ~rom 1 to 56 to an analog multiplexer 146 the multiplexer 146 can have a 6uitable number o~ lnputs ~9 for example 64 inputs as shown. Inputs 1-56 ars connec~ed ~o the cylindrical ~xpandable member 46. Inpu s 57-58 can be grounded ~ ~hown.
Inputs 59-62 can be conneoted to a positive voltage supply an~ lnputs 63-64 are connected to yround. One or two o~
these inputs can be utilized forproviding a synchronization ~ignal for demultiplexing as hereinafter described.
The multiplexer 146 i~ dri~en by a 6 bit binary counter 151 which is supplied with a clock.frequ~ncy ~rom an oscilla~or 152 that is controlled by cry~al 153 of a suitable frequency as for example, 200 KHz. The 200 KHz oscillator frequency provides a five microsecond cycle length per channel as shown in the waveform. The count~r 151 supplies an output 156 in Figure 13, on ~ix lines 157 to the multiplexer 146. The multiplexer 146 i~ provided with an output 158 which is controlled by the binary counter 151 so that the o~tput ~rom each o~ the ampli~iers 141 appears on the line 158 ~or the five microsecond pulse length provided by oscillator 152. In the Figure 13, waveform 156 æhows information being received on 56 channels with ~ach channel having a ~ microsecond duration followed by a 2~ synchronizing pulse 159 which is 20 microseconds wide to complete one cycle of the multiplexer o~ 320 microseconds o~ 146 ~ollowed by the next 320 microsecond cycle. This provides an e~ective ~mpling rate o~ about 3000 ~a~ples p0r second.
The output 158 is connected to ~ bu~er ampl~fier 161 which provides ite output on pin 3 o~ the connector 24.
The other pins 1 and 2 o~ the connector 27 ara connected to ground ~nd a plus voltagQ re~pectively. The pins 1 and 2 in the connector 24 are eionnected to ground ~nd a plus 3~ voltage respectively in the inter.ace module 17.

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r ~ 3 16~

Thus the power ~r the chip ~6 ir, supplied ~rom the inter~ace module 17 through pins 1 and 2 o~ the connector 27. Pin 3 in the c~nnector 14 receive3 the output ~ignal ~rom pi~ 3 of the connector 24 and ~upplies it through a line 164 to a demultlplex r 166. The demultiplexer 166 i8 provided w.ith a plurality o~ output channPls 167. A~uming there ~re 64 lnput channel~ in the multiplexer 146, ther~
would be a corre~ponding number of output ch~nn~ls ln the ~emultiplexer 166.
Th~ in~ormation on the llne 164 contAinlng the synchronizing 6ignal is ~lso æuppliQd through a aapaci~or Cl to a phase locked loop (PlL) 168 and i~ connected to an RC filter networX 169 consisting of a resistor R5 an a capacitor C2 connected to ground. Th~ PLL 168 is provided with an output line 172 and has provided thereon a reconstructed 200 Xhz voltage contr~lled oscillator output which is ~upplied ~ a counter 173. The counter 173 i5 provided with a plurality o~ output line~ 174 which arP
conn~cted to the demultiplexer 166. The lines 174 are provided with freguencies ranging r~m 100 KH2 to 3.125 X~z with the 3.125 KHz line 174 being connected t~ ~he p~ase lock loop 168 by a line 176 which serves to couple the ~C~
output to the phase lock loop. The use of teh PLL all~ws the reconstru~tion of the 200 ~z clocX, which is 2~ 6ynchronized to t}l~ 200 }~z clock 152 in the catheter chip 86 .
The demultiplexer 166 serves to demult~ plex the ~nformation ~upplied ~rom the multiplexer 146 and ~upplies it on the 56 channels 167 to circuitry 181 which includes sample and hold circuitry, ~ilter c~rcuitry and A~D
conYerters to provide an output on lines 182 $n the fo~m of ~ ~ignal which is supplied t~ the computar 31 and to the display monitor 33. ~he computer 31 1B provided with software which has the ~apability of analyzing informati~n being eupplied to it by utilizing sampling technigue~ well known to those ~n the art. The computer 31 per~orms an A-54132/~CH

~17-~nalysl~ ~n the lnformation an~ ~y U~e o~ pr~pagation and delay time analy6i~ ldenti~i~s~nd i~olates the area within the ventricle which m~y contai.n a re-entry pathway which may need to be ablated. This information is displayed on the screen o~ the monitor 33 ~o that it can be r~viewed by the physician so that the physician can make a decision as to whether or not ablation ls deslrable.
Lst it be assumed tha~ re-e:ntry pathway has been located ~nd ~t is desired to a~la~e ~he ~ame. A~ter the mapping has been accomplished by use of the catheter or probe 22 as hereinbefore described, the same catheter or probe 22 while ~till in place within the ventricle may be u~ed ~or accomplishing the ablation. Tha attending physician input~
the desired command~ to the ~eyboard ~not shown) connected to the computer 31 to give the command to pr~ceed with an ablation. As ~o~n as such a command is received by th~
computer 31, the computer 31 6ends a channel number ~erially t~ pin 3 of the connector 26 which is connected to the corresponding pin 3 of the connector 23 in ~ 6erial to parallel shift re~ister 186 which is disposed in the catheter probe 220 The shift registPr 186 ~upplies the channel number to the demultiplexer 186 on the 5iX lines 187 t9 a high voltage demultiplexer 191. The ~hi~t reyister 186 is provided with a clocking ~ignal on pin 4 Q~ the connector 23 which is supplied with a cloc~ 6ign~1 on the correeponding pin 4 o~ the c~nnector 26 ~rom the computer 31.
~he output o~ computer 31 i6 al&o connected to a h~gh voltage ~blation power 6upply 196 wh~ch is programmable a~ to channel number ~nd to the amount o~ energy to ba 6upplied on the channel and ~upplies lt~ output to p~n6 1 and 2 of the connector26 which i5 connected to corresponding pins 1 and 2 ~ the connector 23 whioh are connected to th~
demultiplexer 1911 The high volt~g~ demultiplexer lgl i6 provided with high voltage translstors which can tolerata 3~ the ablati~n voltayes ~uppli~d by the power supply 196.
Upon command, the ablation power supply lg6 supplies a hiyh A-54132/Ht:H

-18~

voltage, high frequency (typically 50-100 volts at 750 KHz to 1 MRz) pulse acros~ the pins 1 and 2 of connector 26.
This high voltage pul~e app~ar~s on the corresponding plns 1 and 2 of the conn~otor 2:~ and i~ ~upplied by the demultlplexer 191 t~khe appropriate channel andappropriate electrode pair through lines lg2 connected to the leads 74.
This pulse appears across the ellectrode pair and causes an ablation to occur in the tissue o~ the wall of the ri~ht ventricle between the electr~de pair. Alternatively, ablation can be ~cco~pllshed between one of the electrode pairs and an external ground electrode placed on the ohest of the patient. In this manner, it can be een that a highly controlled ablation is provided which i5 precisely po~itioned with respect to the selected electrode pair.
Several milli~ec~nds after the ablation pulse ha~ been supplied to the appropriate electrode pair, mapping can ~gain be resumed in the manner heretofore described to ~certain whether or not a re-entry pathway is 6till present. If the m~pping indicates that at least a portion of th~ r~-entry pathway i ~till present, high voltag~ pul~e~ c n be programmed by the computer and ~upplied to ~th~r appropri~te electrode pairs .until the re-entry pa~hway has been destroyed. From the pattern of the electrodes provided by the el@ctrode array 46, it can be 6een that a compact multiple ~lectrode grid-liXe pattern i~ provided having electrode pairs prerisely located throughout the entire sur~ace o~ the wall o~ the heart forming the chamber in which the elelctrode array ~6 is disposed ~o that ablation can be precisely controlled.
Programmed ~timulation can be per~ormed by using a selectabl~ number of electrodes. In thi~ mode 9~ operation the interface 29 provides a programmable level ~ low vol~age pulse~ (5-10 volt~ via the high volt~ge line to ~timulate the heart with ~ynchroniz2d pulses in order ~o induce or convert ~n arrythmia .

A-54132/HC'H

, , ~;

--lg~

The skaggered radiopaque markers 65 can be utilized to ascertain which o~ the arms 47 of the ~xpandable member 46 i8 located closes to the ~natomical point of interest ln the heart cavity a~ rOr example the bundle of His. By observing thi ~taggered relationship ~f the marker~ 65, the physician an ~elPct th~ ~ignals coming ~rom a speci~ic arm 47 to analyze the same in the oomputer 31 to thereby ascertain the condition o~ the ~undle o~
~he 6tagger~d relation~hlp o~the ~arker~ 65 al~o~ake it possible for the ~ttending physician to observe the amount of rotation which occurs in the expendable ~ember 46 when it is rotated by rotation of the proximal extremity o~ the catheter probe 22. For ~xample, 6ince only ~lve o~ the markers 65 are used on the righ~ arm which are spaced circumferentially by4S it is readily ascertainable whether rotatin of 45 has occured or more or less. If rotation of 45~ has occured, a marker 65 will be ~hi~ted to a di~ferent stagger2d posi~ion to the other side o the expandable member 46 which will be in registration with an arm 47. If rotation of less than 45~ has occured, the o~fset marker 65 will not ~e in alignment with one ~f the armks 47.
By providing an additional lum~n in the catheter which i~ commonly accomplished in catheter~ and having that lumen open through a port into the right ventricle, it is possible to measure the pressure in the right ventricle during mapping or ablati~n. ~y measuring the pressure in the right ventricle, it is po~sible to ascertzin when the ventricle is filled with blood or whether i~ i~ being 6gueezed. The timing of the ablation can be such that abla~on oecur6 when the ventri~le is 6queezed to its ~mallest ~ize. Thl6 may be desirable bec~u~e ~t this point ther~ will be the b~st contact between the electrod~ array 46 nd the heart w~ll ~orming the ~entrlcle. In ~ddition, it is desirable to 3~ carry out thle ablation at thi~ point in ti~e because at that time ~hat the amount of blood in the v~ntricle is at a A-S4132/H~,H

.: :, ::, , .:

J ,,~_ "" Ç,_ ,~

~20-minimum. Thus, more of the energy created by the ablation pulse is di6sipated lnto the heart wall rather ~han into th~ po41 of blood ln the right ventr~cle. Also, in order to acoompli~h this, ~ pres~ure kransducer 201 can be pro~ided in the cylindrical ~ember or electrode array 46 and conne~ted to electrical wire~ not ~hown .into the multiplexer 14S.
In ~oordance with the pr96eJlt invention, it ca~ bP
~een that catheter probe 22 can be provided with an incr~ased number of electrodes lf desired. Additional channels can be readily provided in the multiplexer 146 and demultiplexer 166. The ~hape of the electrode array 46 can be made ~o that it con~orms to th wall o~ the heart ~s it expand~ and contracts through the entire cardiac cycle. This is made possible because o~ th~ springiness o~ the individual arms 47 of the expandable member 46. Intima~e contac~ is main~ained with the wall of the heart minimizing the amount of energy which i6 dissipated into the blood pool within the cavity ~ the heart during ablation.
With the catheter, ~yst~m and method o~ the present . invention, mapping and ablation procedures can be ~arried out within relatively short periods of time, as for example, as little as one half hour. The construction of the catheter is ~uch that it will not interfere ~ubstantlally with the cardiac output of the heart. It should be appreciated that if de~ired, ablation can be accompli~hPd with a separate -atheter or device. It ~hould also be obvious that if desierd th2 ~y6tem ~ay be used to perform a routine ~lectrophy~iology ~tudy on ~ pat.ien~ util~zing the programmed stimula ion xnd mapping ~eatures o~ ~ystem.

Another embodiment o~ a catheter probe incorporating the present inventi~n i~ 6hown in Figures 16-20. As ~hown therein, the catheter probe 211 which con~i~t~ o~ a ~leYible elongate tu~ular member 36 very similar to the ~lexible elongate tubular member 36 hereinbefore described in the previous embodiment.

'' :, ~

~21-A plurality of longitudinally a~d radlally ~pacedapart sets 216 of bipolar electrodes~ 217 and 218 are provided - beyond the distal extremity of the ~lexible elongate tubular me~ber 3S. Expandable means is secured to the distal extremity of the flexible elongate tubular member 35 for carrying and ~upporting the ee~s 216 o~ electrodes 217 and 218. In the ~mbodiment 6hown in Fi~ures 1~-20, the expandable means taXes the ~orm of a s~ngle flexible elongate ~trip or element 221 Sormed o~ a ~uitable mater$al ~uch as the plastic utilized for the arms 47 ln the hereinbefore described embodiment of khe pre~ent invention. The single flexible elongate ~trip 2~1 is utili~ed which i8 wrapped in a ~piral fashion and is movable be~ween con~racted ~nd expanded positions. The contracted position is shown in Figure 16 and an expanded positlon is ~hown in Figure 19.
~he flexible elongate strip 221 is provided with an outer ~urface 2~2 and an inner 6urface 223. The ~ets o~
electrodes 216 can be formed as multilayer electrodes 217 and 218 on the outer ~urface 222 in the manner hereinbefore described for the previous embodiment and ~an have ganerally the ~ame ~lze and chape. Leads ~not ~hown) can al60 be formed on the inner sur~ce 223 in ~ manner ~imilar to tha~
hereinbefore described. The bipol~r pairs of electrodes 217 and 218 ~re disposed longitudinally o~ the s~rip 221 or in other words in a helical directi4n as shown. I~
desired, the bipolar pairs oP electrodes 217 ~nd 218 can be arranged ~n different manners on .he 6trip. ~or example, they can be 6taggered ~o th~t they extend in a direction which ia at right angles to the longitu~i~al axi~ o~ the flexible ~longate member 36.
It ~hould be appreciated that if ~t i8 desired to achieve improved voltage propagation between the bipolar electrodes, a c~ncentric arrangement ~f the ~ipolar electrodes ~an be utllized. As 6ho~n ln Figure 21, each 6et 226 of bipolar electrodes 227 and 228 has ~he elec~rode 227 is the ~orm o~ a circular disc and electrode 228 as an annulus disposed coaxially with respect to the disc 227.
The electrodes 227 and 228 can be multilayered as the electrodes 67 and 6B hereinbef~re described. By way of examplP, the electrode 227 ca:n ha~e a diameter o~ .030"~
the space between the elec rode 227 and the ring electrode 228 .030" with th~ ring elec~;rode 228 having a width of approximately .010", ~he set~ 2Z6 o~ electrod~s 227 and 22~ can be ~paced lengthwise o~ the fl~xible elongate strip 221 80 that they are sp~ced apart radially and longltudinally when the ~lexible elongate strip 221 lfi wrapped in the spiral manner shown in Figure 16.
Means is provided for moving the expandable means ~xpanded between expanded and cor~tracted positlons and consists of an elongate cylindrical tubular member 231 ~ormed of a 6ultable material such as plastic havlng an annular recess 232 at the proximal extremity thereo~, a plastic tube 233 formed o~ a hea~ishrinkable mat~ri~ 6hrunk over the proximal extremity o~ khe tubular member 231 nd is 6eated within the recess 232. It i~ also shrunk over the dl~tal . extremity of the mandrel 92 to ~ecure th~ tubular member 231 to-the mandrel 92. Another plastic ~r metal ~ylindrlcal tubular member 234 i6 provided in the form of a rounded tip.
Cooperative mean~ is pro~ided ~or r~t~tably mounting the cylindrical tubular member 234 on the distal ~xtremity of the cylindrical member 231 and consi~ts o~ a fsmale recess 236 ~ormed in distal extremity of the cylindrical member 231 which i~ ad~pted to receive by ~ snap-in ~it ~ male pro~rusion ~37 4n the tip member. Thu~, it can be ~een that there can be relatlve rotation between the cyllndr~cal ~ember 231 and ~he cylindrical member 234 w~ile re~training longitudinal ~vement between the ~ame.
Means 1~ provided ~or rotating the tip member 234 wi~h respect to the di6tal extremity o~ th@ cylindrical member 231 and consists o~ a torque element or wire 246 which ~xtends from the proximal extremi~y o~ the ~lexible elongate tubular member 36 through the hole ~7 o~ ~he mandr~l 92 and .

~23- ~g ~

through a hole 247 in the cylindrical ~ember 231 and is coupled to the tip member 234 by extending into a hole ~48 in the tip member 234 and bonded therein by ~uitable means such as solder or an adhesive.
One of the e~ds of the flexible elongate ~trip 221 is ~ecured to the distal extremity o~ the tip member ~34 by ~uitable means such a band 251 and an adhesive. Similarly the other of the ends of the Ilexible elongate ~trip 221 is ~ecured ~o ~he di6~al Qx~remlty o~ the ~andrel 92 in a 6uitable manner ~uch ~s clamping it under thP cover 103.
The t~rgue wire 246 can be connected to the knob 117 hereinbefore described which can be utilized for rotating the torque wire 246 rather than controlling the pull wire as in the previous embodiment.
The fl~xible elongate strip 221 1~ wound on the tubular me~ber 231 in a clockwise direction and i8 relatively tightly wrapped as 6hown in Figure 16 to a~sume its contracted position. The ~lexible elon~ate 6trip 221 can b~ moved to an expanded position by r~tation of the torque el~ment or . wire 246 and the tip ~ember 234 secure~ thereto in a coun erclockwis~ direction to cause the turns of the helix of the ~lexible ~trip ~21 to gradually expand in a circumferential direction t~ an expanded position ~imulating ~ position ~uch as that ~hown in Figure 19, that it w~uld 2~ assume within a chamber o~ the hear and to mova the electrodes 217 and 218 carried thereby into engagement with the wall forminq the chamber of the heart in which the expandable means is dlsposed.
The leads (not show~) on the in~er ~ur~ace 223 are connected to a multlplexer chip 86 pr~vided ~n the distal extremi~y of the ~lexible elongate member 36 in ~he ~ama manner a~ heretobefore described in c~nnect~on wi~h ~he pr~ious embodimentt Th~ multiplexer 86 is connected by leads to the inter~ace module 29 and to the computer ~1 in the ~ame manner as the previously described embodiment.

..

~. ' ' ' ` .

The catheter probe 211 oP kh~ embodiment ~hown in Figur~
16 - 20 can be readily introduc0d into a chamber o~ the heart in the same manner as the e~bocliment o~` the catheter probe hereinbe~ore described. As 800n AS ~he distal extremity of the catheter or probe211 i~ po~itloned within the d2~ired cavity o~ the heart, the knob 121 can be rotated in the ~ppropriate direct~on to cause unwinding o~ the 6pirally wrapped ~l~xible elongate ætrip 221 to cau~e it to progressively enlarg~. Rotakion i~ con inued until the enlargement is 6ufficient to bring the electrode~ 217 and 218 carried thereby inko engage~ent with the wall o~ the heart forming the chamber in which the distal ~xtremity of the catheter or probe 211 i~ disposed. By applying additional rotational forces to the knob 117, the ~ize of the spiral formed by the fl~-xible elongate ~trip 221 can be increased until all or substantially all of the electrodes carried by the strip 221 are moved into engagement with the wall. sinc2 the strip 221 is fl~xible, the heart can continue its normal beating pattern in moving the wall forming the chamber inwardly and outwardly. At the ~ame ~ime, the spacing provided between the turns of the 6piral formed by the ~lexible elongate ~trip 221 permits normal substantially unimpeded blood flow in the ch~mb~r in which the catheter probe 211 is located. The ~pringiness of the ~lexible elongat~ ætrip 221 permits the ~lexible elongate element or ~trip 221 to ~ollow the muscular contractions and expansions o~ the heart while 8till maintaining the electrodes in continuous contact with the heart wall and in contact with electrical circuitry provided within the heart w~ll.
When the desired potential mea urement~ have been made which will give potenti~ls extending ax~und the 360~ o~ the chamber, add~tional potential ~easurement~ can be ~de by partially contracting the 6pirally wound ~lexible elongate 3~ strips 221 by rotation o~ the knob 117 in an opposite direction the distal extremi~y o~ ~he probe 2~1 an be ~,I-`'R';, ~I7;~ 3 rotated through a desired angle, as for example, 15. rrhe lexible elongate strip 221 can then again be moved to an expanded position into engagement with the he~rt wall and additional potential ~easurement~ made.
If thereafter, lt i8 de6ired to carry out an ablation step, thi~ can be ~cc4mpliehed in the manner hereinbe~ore described by providing a high voltage between ~ selected set of bipolar el~ctrodes.
Thereafter, aft~r the de!iir~d procedures have been lo carried out, the catheter probe ~11 can be removed ~rom the ~ody by operating the knob 117 to move the ~lex~ble elongate strip 221 lnto its contract~d position helically wrapped about the tubular member 231. The entire catheter probe 211 can then be removed in a conventional manner.
Xt ~hould be appreciated that rather than providing a single flexible elongate element or ~trip 221, ~ plurality of such rlexible elements or strips can be provided which are disposed adjacent to each other to form a plurality oP
helices. The helices can be wound into a plurality of abuttin~ or nearly abutting helices which can be expanded and contrac~ed in the Rame manner as a single helix ~ormed from a single ~lexible elongate ~ember ~trip 221.
From the ~oregoing, it can be ~een that 6everal embodiments of the present invention have been provided which can be utilized for carrying out endoc~rdial mapping an~
ablation. All of the emb~diments make po~sible the mak~ng o~ simultaneous measur2ments at many porti~ns o~ the w~ll fcrming the chamber o~ the heart in which the cath~ter pro~
i6 disposed, ~aking it possibl~ to make simultaneous potential measurements from such portions ~xtending through 360. Thus, it is possible to map khe entire heart wall forming the chamber in a ~ingle step wi~hout the necessity o~ r~tating the catheter prob~ to several rotational p~sit~ons which may be Yery time c~nsuming. In additisn, wi~h such different positions ~t m~y b~ di~ieult ~o .

-26~

precisely ascertain where the measurements were made in the chamber of the heart.
All of the embodiments of the invention have the advantage that during operation of the probe within the chamber, the heart can continue its normal operation with substantially unimpeded blood ,~low in the chamber because of the ~pacing proYided between expandable mean0 carryiny the ~lectrodes.

A-54132/Ht:H

:

~. : ;

Claims

1. An endocardial mapping and/or ablation system for introduction into a chamber of the heart formed by a wall by passage through a lumen leading to the chamber in the heart having blood therein comprising a catheter probe having proximal and distal extremities and comprised of a flexible elongate tubular member having at least one lumen extending therethrough extending the length thereof and having a distal extremity, a plurality of longitudinally and radially spaced apart electrodes, expandable means secured to the distal extremity of the flexible elongate tubular member and being movable between a contracted position and an expanded position, means mounting said electrodes on aid expandable means whereby when said expandable means is moved to the expanded position in the chamber of the heart the electrodes are moved into engagement with the wall forming the chamber of the heart, and means coupled to the expandable means for moving said expandable means between said contracted and expanded positions, said expandable means having spaces therein when in the expanded position through which the blood can flow, lead means in contact with the electrodes and extending into said flexible elongate tubular member, and electrical means connected to said lead means for performing electrical functions with respect to said electrodes, said electrical means including a multiplexed mounted in the catheter probe and coupled to said lead means.

2. A system as in Claim 1 wherein said expandable means is sufficiently flexible 50 as to cause said electrodes to remain in contact with the walls of the chamber while permitting movement of the wall of the heart during contraction and expansion of the chamber.

3. A system as in Claim 1 wherein said expandable means is comprised of at least one flexible tubular member having an outer surface and an inner surface and wherein said electrodes are secured to said outer surface and wherein said lead means includes leads secured to the inner surface.

4. A system as in Claim 1 wherein said expandable means includes at least one flexible elongate element in the form of a helix.

5. A system as in Claim 1 wherein said expandable means includes a plurality of circumferentially spaced apart flexible elongate elements having proximal and distal extremities, said proximal extremities being interconnected and said distal extremities interconnected.

6. A system as in Claim 1 wherein said electrical means includes means for mapping potentials encountered by the electrodes in contact with the wall of the heart forming the chamber.

7. A system as in Claim 1 wherein said electrical means includes means for supplying a high voltage at high frequency to selected electrodes to cause ablation in a preselected location in the wall of the heart forming the chamber.

8. In a method for performing endocardial mapping and/or ablation of the wall of the heart forming a chamber in the heart by use of a catheter probe having a proximal extremity and a distal extremity and having a plurality of longitudinally and radially spaced apart electrodes carried thereby and having expandable means carrying the electrode movable between contracted and expanded positions, the method comprising the steps of introducing the catheter probe into the chamber of the heart, causing the expandable means to move the electrode into engagement with the wall forming the chamber of the heart while permitting substantially normal flow of blood in the chamber of the heart sensing the potentials encountered by the electrodes multiplexing the sensed potentials within the catheter probe to provide multiplexed signals and conducting the multiplexed signals to the proximal extremity of the catheter probe.

9. A method as in Claim 8 together with the step of supplying a high voltage to preselected electrodes to cause ablation in the wall forming the chamber of the heart.

10. A method as in Claim 9 together with the step of removing the catheter probe from chamber.

11. An endocardial mapping and/or ablation system for introduction into a chamber of the heart formed by a wall through a vessel having a lumen leading to the chamber comprising a catheter probe having proximal and distal extremities and being in the form of a flexible elongate tubular member having at least one lumen extending therethrough and extending the length thereof, a flexible cylindrical member secured to the distal extremity of the flexible elongate tubular member and movable between contracted and expanded position, said cylindrical member having a plurality of circumferentially spaced apart flexible arms having proximal and distal extremities which are secured to and form part of the cylindrical member, said arms having outer and inner surfaces, a plurality of longitudinally spaced apart electrodes carried by each of said arms on the outer surfaces of the arms, lead means on the inner surfaces of the arms in contact with the electrodes and a pull wire extending through said at least one lumen and through said cylindrical member adapted to engage the distal extremity of the cylindrical member for causing movement of the distal extremity of the cylindrical member axially toward the proximal extremity of the cylindrical member so that the arms of said cylindrical member are bowed outwardly to cause said electrodes carried thereby to come into contact with the wall [of the heart forming the chamber], said arms being sufficiently flexible to remain in contact with the wall of the chamber while permitting movement of the wall during contraction and expansion of the chamber.

12. A system as in Claim 11 wherein said arms include spring-like members disposed within the same permitting yieldable movement of said arms as said arms are moved into engagement with the wall forming the chamber of the heart.

13. A system as in Claim 12 wherein said spring-like members are proportioned in size to cause predetermined yieldable movement of portions of said

14. A system as in Claim 13 wherein said spring-like members are proportioned in size to cause the arms to bow outwardly in a predetermined shape to thereby more closely approximate the conformation of the extremities of the chamber in the heart.

15. A system as in Claim 11 together with electrical means coupled to said lead means for performing electrical functions with respect to said electrodes.

16. An endocardial mapping and/or ablation system for introduction into a chamber of the heart formed by a wall through a vessel having a lumen leading to the chamber comprising a catheter probe having proximal and distal extremities and being in the form of a flexible elongate tubular member having at least one lumen extending therethrough and extending the length thereof, a flexible cylindrical member secured to the distal extremity of the flexible elongate tubular member and movable between contracted and expanded position said cylindrical member having a plurality of circumferentially spaced apart flexible arms having proximal and distal extremities which are secured to and form part of the cylindrical member, said arms having outer and inner surfaces, a plurality of longitudinally spaced apart electrodes carried by each of said arms on the outer surfaces of the arms, lead means on the inner surfaces of the arms in contact with the electrodes and a pull wire extending through said at least one lumen and through said cylindrical member and adapted to engage the distal extremity of the cylindrical member for causing movement of the distal extremity of the cylindrical member axially toward the proximal extremity of the cylindrical member so that the arms of said cylindrical member are bowed outwardly to cause said electrodes carried thereby to come into contact with the wall, said arms being sufficiently flexible to remain in contact with the wall of the chamber while permitting movement of the wall during contraction and expansion of the chamber said electrical means coupled to said lead means for performing electrical functions with respect to said electrodes said electrical means coupled to said lead means including a multiplexed mounted within the catheter probe and coupled to said lead means and a demultiplexer remote from the catheter probe connected to the multiplexed.

17. A system as in Claim 16 wherein the demultiplexer is connected to the multiplexed by leads extending through a lumen in the flexible elongate member.

18. A system as in Claim 16 for use in ablation as well as mapping and wherein said electrodes on said arms are provided in bipolar pairs and wherein said electrical means includes a high voltage source for supplying a high voltage to a selected bipolar pair to cause ablation in the wall of the chamber in a preselected location.

19. A system as in Claim 18 wherein said multiplexed includes a high voltage multiplexed wherein said high voltage source supplies a multiplexed voltage to the catheter probe and wherein said catheter probe includes a high voltage demultiplexer in close proximity to the cylindrical member and connected to the high voltage multiplexed.

20. A system as in Claim 19 wherein the lead means connecting the high voltage multiplexed to the high voltage demultiplexer extend through the lumen in said flexible elongate tubular member wherein said flexible elongate tubular element is provided with a mandrel, said mandrel having a hole extending therethrough and wherein said pull wire extends through said flexible elongate tubular member and through said cylindrical member and through the hole in the mandrel, said pull wire having an enlargement on the distal extremity thereof so that it cannot be pulled proximally through the hole in the mandrel whereby the pull wire serves to move the distal extremity of the cylindrical member toward the proximal extremity of the cylindrical member to cause movement of the cylindrical member from its normal contracted position to an expanded position.

21. A catheter probe as in Claim 11 wherein said cylindrical member comprises first and second mandrels having openings therein and wherein said cylindrical member is formed of a sheet of material having end portions which overlap each other and are secured to said first and second mandrels.

22. A catheter probe for use in endocardial mapping and/or ablation system comprising a flexible elongate element having proximal and distal extremities and having at least one lumen extending therethrough, a flexible cylindrical member secured to the distal extremity of the flexible elongate element and being movable between a normal contracted position and an expanded position, said cylindrical member having a plurality of circumferentially spaced longitudinally extending flexible arms having proximal and distal extremities which are secured to form a part of the cylindrical member, each of said arms having an outer surface and an inner surface, a plurality of spaced apart electrodes disposed on the outer surfaces of each of the arms, conductor means including conductors carried by said arms on the inner surfaces of the arms and connected to said electrodes and extending to the proximal extremity of the flexible elongate element.

23. A catheter probe as in Claim 22 wherein said conductors are adherent to the inner surfaces of the arms.

24. A catheter probe as in Claim 22 wherein each of said arms includes a spring like element disposed therein.

25. A catheter probe as in Claim 24 wherein at least certain of said spring like elements are provided with a predetermined configuration to provide a predetermined conformation to the arms as they are bowed outwardly so as to conform more closely to the chamber of the heart.

26. A catheter probe for use in endocardial mapping and/or ablation system comprising a flexible elongate element having proximal and distal extremities and having at least one lumen extending therethrough, a flexible cylindrical member secured to the distal extremity of the flexible elongate element and being movable between a normal contracted position and an expanded position, said cylindrical member having a plurality of circumferentially spaced longitudinally extending flexible arms having proximal and distal extremities which are secured to form a part of the cylindrical member, each of said arms having an outer surface and an inner surface, a plurality of spaced apart electrodes disposed on the outer surfaces of each of the arms, conductor means including conductors carried by said arms on the inner surfaces of the arms and connected to said electrodes and extending to the proximal extremity of the flexible elongate element said conductor means including a multiplexed, said multiplexed being disposed in close proximity to the cylindrical member and being connected to the conductors connected to the electrodes, together with leads extending from the multiplexed through a lumen to the proximal extremity of the flexible elongate element.

27. A catheter probe for use in endocardial mapping and/or ablation system comprising a flexible elongate element having proximal and distal extremities and having at least one lumen extending therethrough, a flexible cylindrical member secured to the distal extremity of the flexible elongate element and being movable between a normal contracted position and an expanded position, said cylindrical member having a plurality of circumferentially spaced longitudinally extending flexible arms having proximal and distal extremities which are secured to form a part of the cylindrical member, each of said arms having an outer surface and an inner surface, a plurality of spaced apart electrodes disposed on the outer surfaces of each of the arms, conductor means including conductors carried by said arms on the inner surfaces of the arms and connected to said electrodes and extending to the proximal extremity of the flexible elongate element a mandrel disposed in the distal extremity of the cylindrical member, said mandrel having a hole extending therethrough together with a pull wire extending through said flexible elongate element and said cylindrical member and through the hole in said mandrel, said pull wire having an enlargement on the distal extremity thereof which is of a size so that it cannot be pulled through the hole in the mandrel and serving to move the distal extremities of the cylindrical member toward the proximal extremity of the cylindrical member when the pull wire is pulled to cause movement of the cylindrical member from its normal contracted position to an expanded position.

28. A method for forming a flexible cylindrical member for use with a catheter probe providing a sheet of flexible insulating material having a predetermined length and width, forming end portions on two opposite sides of one dimension of the sheet, placing the plurality of parallel slits in the plastic material extending from said end portions in directions generally perpendicular to the end portions to provide a plurality of laterally spaced arms extending longitudinally between said end portions, forming a plurality of spaced apart electrodes on each of said arms, forming leads carried by said arms in contact with electrodes, wrapping the flexible sheet of insulation material into a cylinder and securing said end portion to retain said cylindrical shape for said sheet whereby a cylindrical member is provided having proximal and distal extremities with the arms being substantially equally distributed around the circumference of the cylindrical member, and providing means for moving said proximal and distal extremities toward each other to cause the arms to be bowed outwardly.

29. A method as in Claim 28 together with the step of providing spring like material in the insulating material to provide springiness to the arms.

30. In a method for carrying out endocardial mapping and/or ablation within a chamber of the heart utilizing a catheter probe having proximal and distal extremities with a flexible cylindrical member secured to the distal extremity, the cylindrical member and having a plurality of circumferentially spaced longitudinally extending flexible arms with a plurality of spaced apart electrodes carried by each of the arms advancing the catheter probe into a chamber of the heart so that the cylindrical member is disposed within the chamber, causing the arms of the cylindrical member to bow out so that the electrodes are placed in contact with the wall of the heart forming the chamber in which the mapping and/or ablation is to be carried out, picking up the potential signals from the electrodes and ascertaining whether or not an infarct is present in the wall forming the chamber.

31. A method as in Claim 30 wherein the electrodes are formed in bipolar pairs on the arms together with the step of ascertaining which of the electrode pairs are adjacent to the infarct, and supplying a high voltage to the selected bipolar electrodes to ablate tissue in the wall in the vicinity of the infarct to thereby attempt to destroy the infarct.

32. A method as in Claim 30 together with the step of multiplexing the signals received from the electrodes to reduce the number of connectors required for the catheter probe and demultiplexing the signals outside of the catheter probe.

33. A method as in Claim 31 wherein the high voltage is supplied to the electrodes by multiplexing the high voltage signals remote from the catheter probe and then demultiplexing the high voltage signals in the vicinity of the cylindrical member.

34. In a catheter probe for use in endocardial mapping and/or ablation system for introduction into a chamber of the heart formed by a wall by passage through a lumen leading to the chamber in the heart, the catheter probe comprising an elongate tubular member having at least one lumen extending therethrough extending the length thereof and having a distal extremity, a plurality of longitudinally and radially spaced apart electrodes, expandable means secured to the distal extremity of the flexible elongate tubular member and being movable between a contracted position and an expanded position, said expandable means including at least one flexible elongate element in the form of a helix, means mounting said electrodes on said expandable means whereby when said expandable means is moved to the expanded position in a chamber in the heart the electrodes are moved into engagement with the wall forming a chamber of the heart in which the expandable means is disposed, and means coupled to the expandable means for moving said expandable means between said contracted and expanded positions, said expandable means having spaces therein through which the blood can flow, means in contact with the electrodes and extending into said flexible elongate tubular member.

35. A catheter probe as in Claim 34 wherein the means coupled to the expandable means includes first and second members rotatably mounted with respect to each other, one end of said flexible elongate element being secured to one of said first and second members and the other end of said flexible elongate element being secured to the other of said first and second members and torque wire means secured to one of said first and second members for causing rotation of said one member with respect to the other member for causing movement of said at least one flexible elongate element between contracted and expanded positions.

36. In a method for forming a flexible expandable member for use with a catheter probe, the method comprising a flexible elongate element of insulating material, forming electrodes on the element on one side thereof, wrapping said element into a helix by one end of the element with respect to the other end of the element in one circumferential direction to provide a cylinder, and rotating one end of the flexible elongate element with respect to the other end of the flexible elongate element in an opposite circumferential direction to cause the helix previously formed to expand to move the electrodes carried thereby in an outward direction.