1 2
ing proximal and distal extremities. A plurality of cir
STEERABLE CATHETER WITH ADJUSTABLE cumferentially spaced-apart flexible elements are disBEND LOCATION posed in the distal extremity for causing bending of the
distal extremity of the flexible elongate member. Mov
This is a continuation of application Ser. No. 5 able means is disposed in the distal extremity of the 07/983,962, filed Dec. 1, 1992, now abandoned. flexible elongate member for selecting the location
This invention relates to a steerable catheter with an where bending in the distal extremity will take place, adjustable bend location and method. More in particular, the steerable catheter 11 incorpo
In certain procedures, as for example ablation proce- rating the present invention consists of a flexible elondures for use with a steerable catheter in the human 10 gate member 12 formed of a suitable material such as heart, it has been found that it is difficult to provide a plastic which is provided with proximal and distal exbend in the appropriate location in the distal extremity tremities 13 and 14. An ablation electrode 16 is carried of the steerable catheter while mamtaining the rigidity by the distal extremity 14. A hand-held control mechaof the distal extremity. This has found to be particularly nism 17 is mounted on the proximal extremity 13. The true in patients having large hearts. There is therefore a 15 hand-held control mechanism 17 can be of various need for a new and improved steerable catheter which types. For example it can be of the type which can be overcomes these difficulties. utilized for actuating pull wires (not shown) extending
In general, it is an object of the present invention to longitudinally of the flexible elongate tubular member provide a steerable catheter with an adjustable bend 12 which are well known to those skilled in the art and location and method. 20 which can be utilized for bending the distal extremity of
Another object of the invention is to provide a cathe- the flexible elongate tubular member 12. Alternatively, ter and method of the above character which can be it can be provided with means for controlling flexible utilized with different types of bending mechanisms for elongate elements having a negative coefficient of exthe distal extremity of the catheter. pansion disposed in the distal extremity 14 of the flexi
Another object of the invention is to provide a cathe- 25 ble elongate tubular member 12 as described in co-pendter and method of the above character in which the ing application Ser. No. 07/793,858, filed Nov. 18,1991. adjustment of the bend location can be readily accom- Means not shown in FIG. 1 is provided for adjusting the plished. bend location in the distal extremity of the flexible elon
Additional objects and features of the invention will gate tubular member 12 which will hereinafter be deappear from the following description in which the 30 scribed in conjunction with specific embodiments of the preferred embodiments are set forth in detail in con- present invention.
junction with the accompanying drawings. In FIGS. 2 and 3 there is disclosed a steerable cathe
FIG. 1 is a side elevational view of a steerable cathe- ter 21 which consists of a flexible elongate tubular memter incorporating the present invention. ber 22 which is provided with proximal and distal ex
FIG. 2 is a side elevational view partially in cross-sec- 35 tremities 23 and 24. A metal ablation electrode 26 is tion showing one embodiment of a steerable catheter secured to the distal extremity 24. A hand-held control incorporating the present invention utilizing a shape- mechanism 27 is mounted on the proximal extremity 23 memory element. of the flexible elongate tubular member 22. The flexible
FIG. 3 is a cross-sectional view taken along the line elongate tubular member 22 is formed of a suitable ma3—3 of FIG. 2. 40 terial such as plastic and is provided with a plurality of
FIGS. 4A, 4B and 4C show four examples of how an circumferentially spaced-apart lumens 31-36, and a adjustable bend location in the steerable catheter makes central lumen 37, all of which extend the length of the possible bends in different locations in the distal extrem- flexible elongate tubular member 22. A plurality of ity of the catheter. flexible elongate elements, as for example three of such
FIG. 5 is a diagrammatic illustration showing the 45 elements 41, 42 and 43, are disposed 120° apart and are manner in which the steerable catheter of the present provided in the lumens 31, 33 and 35. These flexible invention can be utilized in a human heart to provide a elongate elements 41,42 and 43 are disposed in the distal different bend location to make it possible to reach extremity 24 of the flexible elongate tubular member 22 difficult-to-reach portions of the wall forming a cham- and are formed of a material which has a negative coefber in the heart. 50 ficient of expansion. The distal extremities of these fiexi
FIG. 6 is a partial cross-sectional view of another ble elongate members 41,42 and 43 are connected to a embodiment of a steerable catheter incorporating the common ground return 44 provided in the lumen 34. present invention utilizing removable stiffening ele- The three flexible elongate elements 41, 42 and 43 are ments having weakened portions at different longitudi- also connected to conductors (not shown) which extend nal positions of the stiffening elements. 55 to the proximal extremity 23 of the flexible elongate
FIG. 7 is a cross-sectional view taken along the line member and with the ground return 44 connected into 7—7 of FIG. 6. a cable 46 extending from the control mechanism 17 and
FIGS. 8A, 8B and 8C show stiffening elements hav- are connected to a joystick control console 47 of the ing weakened regions in different longitudinal portions type described in co-pending application Ser. No. of the stiffening element. 60 07/793,858, filed Nov. 18, 1991, and which includes a
FIG. 9 is a partial cross-sectional view of the distal joystick 48. The ablation electrode 26 is connected by a extremity of another embodiment of a steerable catheter conductor 51 provided in the lumen 32 and extending incorporating the present invention utilizing telescop- into the control mechanism 17 and is connected to a ing stiffening elements. suitable ablation power supply (not shown) convention
FIG. 10 is a cross-sectional view taken along the line 65 ally used with such catheters. 10—10 of FIG. 9. Bend location adjustment means 56 is provided in the
In general, the steerable catheter of the present inven- distal extremity 24 of the flexible elongate tubular memtion consists of a flexible elongate tubular member hav- ber 22 and consists of a shape-memory element 57
