HEART CATHETER

Abstract

A cardiac catheter having electrodes, including a number of elastic individual carriers, which are each connected to a distal end region of the catheter, wherein the carriers each have a longitudinal axis, a number of electrodes per carrier, wherein the electrodes are arranged in lines on an outside of the respective carrier, the lines extend perpendicular to the longitudinal axis, and a mechanism configured so that the carriers, after an insertion of the distal end region of the cardiac catheter into a subspace of a heart, are capable of being reversibly brought from a first state into a second state, wherein the mechanism spreads out the carriers in the first state such that the electrodes are each applied to an inner surface of the subspace, and the mechanism closes the carriers in the second state such that the catheter having the carriers is removable from the subspace.

Claims

1. A cardiac catheter having electrodes, said catheter comprising a number N of elastic individual carriers T.sub.n with n=1, 2, . . . , N and N{2, 3, . . . , 10}, which are each connected to a distal end region of the cardiac catheter, wherein the carriers T.sub.n each have a longitudinal axis LA.sub.n, a number M.sub.n of electrodes E.sub.n,m per carrier T.sub.n, with m=1, 2, . . . , M.sub.n and M.sub.n5, wherein the electrodes E.sub.n,m are arranged in lines R.sub.k,m,n on an outside of the respective carrier T.sub.n, with k=1, 2, . . . K and K3, the lines R.sub.k,m,n extend perpendicular to the longitudinal axis LA.sub.n, and furthermore the carriers comprise a mechanism by means of which said carriers T.sub.n, after an insertion of the distal end region of the cardiac catheter into a subspace of a heart, are capable of being reversibly brought from a first state into a second state, wherein the mechanism spreads out the carriers T.sub.n in the first state such that the electrodes E.sub.n,m are each applied to an inner surface of the subspace, and the mechanism closes the carriers T.sub.n in the second state such that the catheter having the carriers T.sub.n is removable from the subspace.

2. The cardiac catheter as claimed in claim 1, wherein the carriers T.sub.n each comprise: an elastic longitudinal beam LT.sub.n, the proximal end of which connects the carrier T.sub.n to a distal end region of the cardiac catheter and the distal end of which is a free end; a longitudinal axis LA.sub.n extending along the respective longitudinal beam LT.sub.n; a number K.sub.n of elastic cross beams QT.sub.n,k; and a number M.sub.n of electrodes E.sub.n,m, with m=1, 2, . . . , M.sub.n and M.sub.n5, wherein the electrodes E.sub.n,m are arranged on a respective outside of the respective cross beams QT.sub.n,k, with k=1, 2, . . . K.sub.n and K.sub.n3, wherein the mechanism spreads out the carriers T.sub.n in the first state such that the cross beams QT.sub.n,k extend perpendicular to the respective longitudinal beam LT.sub.n and/or perpendicular to the longitudinal axis LA.sub.n.

3. The cardiac catheter as claimed in claim 1, wherein the carriers T.sub.n each comprise at least three markers of a position acquisition system.

4. The cardiac catheter as claimed in claim 2, wherein the carriers T.sub.n each comprise a flat elastic membrane MEM, which connects the cross beams QT.sub.n,k and the longitudinal beams LT.sub.n of the respective carrier T.sub.n.

5. The cardiac catheter as claimed in claim 2, wherein the cross beams QT.sub.n,k and/or the longitudinal beam LT.sub.n consist of a shape memory alloy.

6. The cardiac catheter as claimed in claim 2, wherein the cross beams QT.sub.n,k and/or the longitudinal beam LT.sub.n comprise fluid chambers, which are capable of being individually filled with fluid or emptied of fluid.

7. The cardiac catheter as claimed in claim 2, wherein the longitudinal beams LT.sub.n are connected to the distal end region of the cardiac catheter in such a way that they are rotatable.

8. The cardiac catheter as claimed in claim 1, wherein the carriers T.sub.n have a number M.sub.n of first electrical lines, made of an electrically conductive, elastic polymer-based material, for the individual contacting of the respective electrodes E.sub.n,m.

9. The cardiac catheter as claimed in claim 4, wherein the flat elastic membrane MEM comprises the following three elastic layers: an upper layer on which the electrodes E.sub.n,m are arranged; a lower layer; and a middle layer in which electrical elastic first lines for contacting the electrodes E.sub.n,m extend, wherein spacers are arranged in the middle layer in order to space apart the upper layer and lower layer at a distance A, and the middle layer comprises a volume through which a fluid can flow.

10. The cardiac catheter as claimed in claim 10, wherein the mechanism is embodied and configured such that the carriers T.sub.n and the electrodes E.sub.n,m are pressed against the inner surface of the subspace in the first state with a predetermined contact force.

11. The cardiac catheter as claimed in claim 1, wherein the mechanism has an inflatable body, which is capable of being filled and emptied, and which is capable of being filled with a fluid in the first state and thereby presses the carriers T.sub.n outward from an inside of the respective carrier T.sub.n.

12. The cardiac catheter as claimed in claim 1, wherein the mechanism has a tube piece or hose piece which is arranged on the end part of the catheter so as to be axially longitudinally displaceable along the catheter and which is designed such that in the second state it is displaced axially distally, so that the carriers T.sub.n come to rest within the tube piece or hose piece, and is displaced axially proximally in the first state, so that the carriers T.sub.n can freely unfold.

13. The cardiac catheter as claimed in claim 1, wherein the electrodes E.sub.n,m only have two different sizes G1 and G2 of contact surfaces, wherein: G22*G.

14. The cardiac catheter as claimed in claim 1, wherein at least one of the carriers T.sub.n comprises one or more additional sensors for acquiring an additional physical or chemical or biological parameter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0080] In the drawings:

[0081] FIG. 1 shows a schematic illustration of a view of a distal end of a catheter according to the invention having a number N=3 carriers T.sub.n, with n=1, 2, 3, from a position along the catheter towards the distal end of the catheter. In the present case, the catheter itself would extend perpendicularly from the plane of the sheet in the direction of its proximal end;

[0082] FIG. 2 shows a schematic side view of the distal end part of the catheter, having carriers that are in the second state;

[0083] FIG. 3 shows a schematic illustration of an arrangement according to the invention of electrodes E.sub.n,m on a surface of a carrier T.sub.n;

[0084] FIG. 4 shows a schematic illustration of a 3D view of a distal end of a catheter according to the invention in a second version, having a number N=3 of carriers T.sub.n with n=1, 2, 3;

[0085] FIG. 5 shows a schematic illustration of a top view of the catheter shown in FIG. 4, wherein the longitudinal beams LT.sub.n each assume an angle of 120 in relation to one another;

[0086] FIG. 6 shows a schematic illustration of a top view of the catheter shown in FIG. 4, wherein the longitudinal beams LT.sub.n each assume an angle of 90 in relation to one another at their connection to the catheter;

[0087] FIG. 7 shows a schematic illustration of a top view of the catheter shown in FIG. 4, wherein the longitudinal beams LT.sub.n each assume an angle of 45 in relation to one another by rotation of the longitudinal beams at their connection to the catheter;

[0088] FIG. 8 shows a schematic illustration of a side view of the catheter shown in FIG. 4;

[0089] FIG. 9 shows a schematic illustration of a 3D view of the catheter shown in FIG. 4 having an inflatable body 108; and

[0090] FIG. 10 shows a schematic illustration of a top view of the catheter shown in FIG. 9.

DETAILED DESCRIPTION

[0091] FIG. 1 shows a schematic illustration of a view of a distal end of a catheter according to the invention having a number N=3 of carriers T.sub.n, with n=1, 2, 3, from a viewing position along the catheter towards the distal end of the catheter. In the present case, the catheter itself would extend perpendicularly from the plane of the sheet in the direction of its proximal end. In the present case, the catheter is shown in a first state, as would result if the carriers T.sub.n were to unfold at the distal end of the catheter freely (elastic neutral state), i.e., undisturbed by external force actions, for example, due to contacts with the inner surface of the subspace of the heart.

[0092] The cardiac catheter shown has a number N=3 of elastic individual carriers T.sub.n 101 with n=1, 2, 3, each of which is connected to a distal end region of the cardiac catheter. The catheter itself is represented by the black dot in the middle of the carrier T.sub.n.

[0093] The longitudinal axes LA.sub.n of the carriers T.sub.n 101 each enclose an angle of 120 in relation to one another. The three carriers T.sub.n 101 each consist in the present case of an elastic membrane element MEM, wherein the membrane element MEM here has three layers: an upper layer on which the electrodes E.sub.n,m 102 (shown in each case as cuboids and circles) are arranged, a lower layer, and a middle layer, in which electrical elastic first lines (not shown) for contacting the electrodes E.sub.n,m 102 extend, wherein spacers are arranged in the middle layer to space apart upper layer and lower layer at a distance A, and the middle layer includes first electrical lines (not shown) made of an elastic, electrically conductive polymer for individually contacting the electrodes E.sub.n,m 102.

[0094] The first lines connect the electrodes E.sub.n,m 102 to an interface (not shown) on the catheter which connects the first electrical lines individually to second electrical lines, which are each insulated gold lines and which lead to the proximal end of the catheter. At the proximal end of the catheter, the second electrical lines are connectable to a corresponding evaluation device.

[0095] In the present case, the carriers T.sub.n 101 each include a number M.sub.n=45 of electrodes E.sub.n,m 102, wherein the electrodes E.sub.n,m 102 are arranged in K=9 lines R.sub.k,m,n on the outside of the upper layer of the respective carrier T.sub.n 101, with k=1, 2, 3. The lines R.sub.k,m,n extend in the elastic neutral state shown (with a stretched-out support structure) perpendicular to the respective longitudinal axis LA.sub.n.

[0096] Furthermore, the catheter includes a mechanism configured so that the carriers T.sub.n 101, after an insertion of the distal end region of the cardiac catheter into a subspace of a heart, can be reversibly brought from a first state into a second state, wherein the mechanism spreads out the carriers T.sub.n 101 in the first state such that the electrodes E.sub.n,m 102 are each applied to an inner surface of the subspace, and the mechanism closes the carriers T.sub.n 101 in the second state such that the catheter having the carriers T.sub.n 101 is removable from the subspace.

[0097] In the present case, the mechanism consists of a support structure, which is integrated into each of the individual carriers T.sub.n 101, and a mechanical linkage (not shown) consisting of a mechanical connection of the three carriers, which enables the supports to unfold and using which folding together of the carriers is implementable. In this example embodiment, the support structure consists of wires 103 made of a shape memory material, in particular of nitinol. The wires 103 extend along the circumferential edge of the carriers T.sub.n (thick black circumferential lines) and two wires 103 (thick dashed lines) along the longitudinal axis LA.sub.n of the respective carriers T.sub.n. The supporting structure is preformed/conditioned in such a way that after a mechanical release it causes the carrier T.sub.n to unfold. The mechanical release is advantageously carried out by an operator when the distal end of the catheter, i.e., specifically the carriers T.sub.n, are introduced into the subspace of the heart to be examined.

[0098] The mechanical linkage (not shown) is designed here as a kind of cable pull in such a way that the spacing apart of the distal ends of the carriers T.sub.n can be variably adjusted thereby. If the cable pull is pulled, the distal ends of the carriers T.sub.n are pulled together, i.e., the carriers are therefore folded in and thus brought into the second state. If the cable pull is released, the carriers T.sub.n unfold and assume a shape preformed by the support structure made of shape memory material (first state).

[0099] The conditioning of the support structure advantageously has the effect that the electrodes E.sub.n,m 102 arranged on the upper layer are also applied to or are pressed against the inner surface of the subspace of the heart with a predetermined driving force even when the heart is beating.

[0100] FIG. 2 shows a schematic side view of the distal end part of the catheter shown in FIG. 1, having carriers T.sub.n which are in the second state. The cable pull 104 can be seen schematically, which causes the three carriers T.sub.n to fold up when pulled together. If the cable pull 104 is released, the carriers T.sub.n 101 thus unfold due to the support structures made of shape memory material.

[0101] FIG. 3 shows a schematic illustration of an arrangement according to the invention of electrodes E.sub.n,m on a surface of an elastic flat carrier T.sub.n. It can be seen that the electrodes E.sub.n,m are each aligned in rows perpendicular to a longitudinal axis LA.sub.n of the carrier T.sub.n. Furthermore, it can be clearly seen that the electrodes E.sub.n,m of a row each have the same shape of the contact surfaces and the same size of the contact surfaces. Furthermore, the electrodes E.sub.n,m of a row are each equally spaced from one another. The electrodes E.sub.n,m of successive rows alternately include electrodes E.sub.n,m having round smaller contact surfaces and electrodes E.sub.n,m having rectangular larger contact surfaces. Individual contacting of the electrodes E.sub.n,m enables a large number of evaluations of differential potentials, as are indicated in FIG. 3 for an electrode on the basis of the arrows shown. The catheter preferably includes an electrode around which blood flows and which decreases a reference potential. The time-dependent potentials ascertained at the individual electrodes E.sub.n,m can be determined against this reference potential.

[0102] FIG. 4 shows a schematic illustration of a 3D view of a distal end of a cardiac catheter according to the invention in a second version, having a number N=3 of carriers T.sub.n with n=1, 2, 3. The cardiac catheter includes: [0103] a number N=3 of elastic individual carriers T.sub.n 101 with n=1, 2, . . . , N=3, wherein the carriers T.sub.n 101 each include an elastic longitudinal beam LT.sub.n 105 made of a shape memory alloy, the proximal end of which connects the respective carrier T.sub.n 101 to a distal end region of the cardiac catheter and the distal end of which is a free end, [0104] a longitudinal axis LA.sub.n extending along the respective longitudinal beam LT.sub.n 105, [0105] a number K.sub.n=4 of elastic cross beams QT.sub.n,k 106, and [0106] a number M.sub.n=18 of electrodes E.sub.n,m 102, with m=1, 2, . . . , M.sub.n=18, wherein the electrodes E.sub.n,m 102 are arranged on a respective outside of the respective cross beams QT.sub.n,k 106, with k=1, 2, . . . K.sub.n.

[0107] Furthermore, each carrier T.sub.n include a mechanism configured so that the carriers T.sub.n 101, after an insertion of the distal end region of the cardiac catheter into a subspace of a heart, can be reversibly brought from a first state into a second state, wherein the mechanism spreads out the carriers T.sub.n 101 in the first state such that the electrodes E.sub.n,m 102 are each applied to an inner surface of the subspace, the cross beams QT.sub.n,k106 extend perpendicular to the respective longitudinal beam LT.sub.n 105 and/or perpendicular to the longitudinal axis LA.sub.n and the mechanism closes the carriers T.sub.n 101 in the second state such that the catheter having the carriers T.sub.n 101 is removable from the subspace.

[0108] Finally, the catheter includes a central operable device 107 for ablation and/or for injection and/or for taking samples.

[0109] Because longitudinal beams LT.sub.n can be rotated about their longitudinal axis at the connection point, the carriers T.sub.n can be arranged differently in relation to one another. FIGS. 5 to 7 show different configurations corresponding thereto. The distal ends of the longitudinal members LT.sub.n are free ends here, and in particular are not connected to one another or to the central device 107.

[0110] FIG. 5 shows a schematic illustration of a top view of the catheter shown in FIG. 4, wherein the longitudinal beams LT.sub.n each assume an angle of 1200 in relation to one another. The device 107 for ablation and/or for injection and/or for taking samples can be seen centrally. Furthermore, the 318 electrodes E.sub.n,m 102 arranged on the outside of the cross beams QT.sub.n,k 106 can be seen, which essentially have the same rectangular shape, with the exception of six electrodes E.sub.n,m on the respective distal cross beams QT.sub.n,k 106, which have a different square shape.

[0111] FIG. 6 shows a schematic illustration of a top view of the catheter shown in FIG. 4, wherein the longitudinal beams LT.sub.n 105 each assume an angle of 900 in relation to one another by rotation of the longitudinal beams at their connection to the catheter.

[0112] FIG. 7 shows a schematic illustration of a top view of the catheter shown in FIG. 4, wherein the longitudinal beams LT.sub.n 105 each assume an angle of 450 in relation to one another by rotation of the longitudinal beams at their connection to the catheter.

[0113] FIG. 8 shows a schematic illustration of a side view of the catheter shown in FIG. 4.

[0114] It can be clearly seen that the longitudinal beams LT.sub.n 105 in the first state are advantageously conditioned in such a way that configurations are settable in which the cross beams QT.sub.n,k 106 can overlap. In the example shown, the longitudinal beams LT.sub.n 105 are vertically spaced apart from the respective cross beams QT.sub.n,k 106, so that overlapping configurations are settable, as shown, for example, in FIG. 7.

[0115] FIG. 9 shows a schematic illustration of a 3D view of the catheter shown in FIG. 4 having an inflatable body 108.

[0116] After the distal end part of the catheter has been inserted into a cavity in the heart, the carriers T.sub.n are unfolded and, by corresponding rotation of the carriers T.sub.n around the local longitudinal axis of the longitudinal beams LT.sub.n at the linkage point, the desired relative configuration of the carriers T.sub.n is set. After the desired relative configuration of the carriers has been set, the inflatable body 108 is filled with a fluid so that it expands and presses the outside of the cross beams QT.sub.n,k 106 with the electrodes E.sub.n,m 102 arranged thereon against the inside of the cavity in the heart.

[0117] After completion of the measurements or after completion of measures using the device 107, the inflatable body 108 is first emptied of fluid, so that the carriers T.sub.n are freely movable again.

[0118] The mechanism advantageously includes a tube piece or hose piece (not shown) which is arranged on the end part of the catheter so as to be axially longitudinally displaceable along the catheter and which is designed such that in the second state it is displaced axially distally, so that the carriers T.sub.n and possibly provided devices for ablation and/or injection and/or for taking samples come to rest within the tube piece or hose piece, and is displaced axially proximally in the first state, so that the carriers T.sub.n and possibly provided devices for ablation and/or injection and/or for sample taking come to rest outside the two-piece or hose piece and can freely unfold and can be used accordingly.

[0119] FIG. 10 shows a schematic illustration of a top view of the catheter shown in FIG. 9 having dimensions in [mm].

[0120] Although the invention has been further illustrated and described in detail by way of preferred embodiments, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention. It is therefore clear that a multitude of possible variations exists. It is also clear that embodiments mentioned by way of examples are really only examples, which are not to be construed in any way as limiting the scope of protection, the possible applications, or the configuration of the invention. Rather, the foregoing description and the description of the figures enable a person skilled in the art to implement the example embodiments, wherein a person skilled in the art in the knowledge of the disclosed inventive concept may make various changes, for example as to the function or arrangement of individual elements cited in an example embodiment, without departing from the scope of protection as defined by the claims and their legal equivalents, such as more extensive explanations in the description.

LIST OF REFERENCE SIGNS

[0121] 101 carrier T.sub.n [0122] 102 electrodes E.sub.n,m [0123] 103 wires made from a shape memory material [0124] 104 cable pull [0125] 105 longitudinal beam LT.sub.n [0126] 106 cross beam QT.sub.n,k [0127] 107 ablation tool [0128] 108 inflatable body