Field

[0001] The present invention concerns a catheter that can be bent in any direction without the need to rotate the catheter.

Description of related art [0001] Catheters science allows entering arteries and veins and carrying out diagnostic procedures (angiography...) and therapeutic manipulations (drugs perfusion, embolization, recanalizations...). The arterial and venous system is highly bi- or multi-furcated. Furthermore, most arteries and veins present with natural curves which can be exaggerated by arteriosclerosis. [0002] Catheters currently on the market have a fixed design: straight, bent, doubly bent. This design can be altered by the coaxial insertion of a guide more rigid than the catheter shaft or by adaptation of the flexible shaft to the vessel curve.

[0003] Thus, the operator who intends to follow an arterial or venous curve or enter an endovascular ostium, sometimes placed at 90° to the vascular axis, chooses the most adapted or adaptable catheter. Sometimes the distance to reach the target segment to be worked out is long and several curves in the three space directions disturb the progression. Under these conditions, fixed straight or bent catheters can face some difficulty to get to the aimed area, especially if curves, stenosis, bifurcations, ostia have to be crossed through.

Summary

[0004] The present invention concerns a catheter comprising: a proximal part, a distal part and a shaft part extending between the proximal part and the distal part; the distal part comprising a flexible, tubular hollow body extending along an axis and that can be bent in a predetermined bending direction that is offset from the axis; a plurality of longitudinally adjacent unconnected elements arranged within the tubular hollow body such that the elements can be moved apart from each other and

compressed against each other along the axis; wherein each element has a section parallel to the axis, such that compressing the elements against each other causes the distal part to bend in at least one predetermined bending direction that is determined by the section of each element of the plurality of elements.

Brief Description of the Drawings [0005] The invention will be better understood with the aid of the description of an embodiment given by way of example and illustrated by the figures, in which:

Fig. 1 illustrates schematically a catheter comprising a distal part, according to an embodiment;

Fig. 2 shows a cross-section view of the distal part comprising a plurality of elements, according to an embodiment;

Fig. 3 shows a section of an element, according to an

embodiment;

Fig. 4 represents the distal portion of Fig. 2 wherein the elements are compressed and the distal part is bent, according to an embodiment;

Fig. 5 represents a variant of the distal part of Fig. 2;

Fig. 6 represents the distal part of Fig. 5 wherein the elements are compressed and the distal part is bent, according to another

embodiment;

Fig. 7 illustrates the distal part, according to another

embodiment;

Fig. 8 illustrates the distal part of Fig. 7 wherein the elements are compressed according to another embodiment;

Fig. 9 shows the distal part, according to another embodiment; Fig. 10 shows the distal part of Fig. 9 wherein the elements are compressed and the distal part is bent in a predetermined direction;

Fig. 1 1 shows the distal part of Fig. 9 wherein the elements are compressed and the distal part is bent in another predetermined direction;

Fig. 12 illustrates a steering assembly of the catheter, according to an embodiment;

Fig. 13 represents the shaft part, according to an embodiment;

Fig. 14 represent the steering assembly, according to an embodiment;

Fig. 15 represent the steering assembly, according to another embodiment;

Fig. 16 shows the steering assembly according to yet another embodiment; and

Fig. 17 shows the steering assembly according to yet another embodiment.

Detailed Description of possible embodiments

[0006] Fig. 1 illustrates schematically a catheter 10 according to an embodiment, the catheter 10 comprising a proximal part 12, a distal part 1 1 and a shaft part 14 extending between the proximal part 12 and the distal part 1 1. The catheter 10 can be a catheter used for the opening of obstructions in bodily vessels. The catheter 10 can further be destined to be used for entering arteries and veins and carrying out diagnostic procedures (such as angiography) or therapeutic manipulations (such as drugs perfusion, embolization, recanalization). [0007] Fig. 2 shows a cross-section view of the distal part 1 1 , according to an embodiment. The distal part 1 1 comprises a tubular hollow body 15 extending along an catheter axis 100. The tubular hollow body 15 is flexible enough such as to be bent in a predetermined bending direction that is offset from the catheter axis 100. [0008] The distal part 1 1 comprises a plurality of longitudinally adjacent unconnected elements 16 arranged within the tubular hollow body 15 such that the elements 16 can be moved apart from each other and compressed against each other along the catheter axis 100. For example, the elements 16 can be compressed together following a pressure on the distal end 1 10 of the distal part 1 1. Such a pressure can be provided when the distal end 1 10 abut against an obstruction in a body vessel or against a wall of a body vessel due to a curve of the body vessel. Preferably, the elements 16 can be compressed voluntarily by a user manipulating the catheter, for example by actioning a steering assembly as will be described below.

[0009] Each element 16 having a section 160 parallel to the catheter axis 100, such that compressing the elements 16 against each other causes the distal part 1 1 to bend in at least one predetermined bending direction that is determined by the section 160 of each element of the plurality of elements 16.

[0010] In the example of Fig. 2, the section 160 has a shape of a truncated triangle having a base 161 and a truncation plane 162. Fig. 3 shows the section 160 a single element 16 of Fig. 2. In the example of Fig. 3, the base 161 is larger than the truncation plane 162 such that the lateral face 166 perpendicular to the catheter axis 100 makes an angle Θ with the base 161.

[0011] Fig. 4 represents the distal part 1 1 wherein the elements 16 are compressed and the distal part 1 1 is bent. In the example of Figs. 2 and 4, the elements 16 comprised in the tubular hollow body 15 have a triangular section 160 such as the one shown in Fig. 3. The elements 16 are arranged in the tubular hollow body 15 such that the truncation plane 162 of each element 16 is radially positioned along a bending line 17, substantially parallel to the catheter axis 100.

[0012] Compressing the elements 16 causes each element 16 to topple towards the adjacent element 16. The predetermined bending direction of the distal part 1 1 is determined by the radial position of the truncation plane 162 that corresponds to the bending line 17.

[0013] The degree of bending of the distal part 1 1, in other word, the degree of curvature along the bending line 17 is determined by the ratio of the length of the truncation plane 162 to the length of the base 161 of adjacent elements 16.

[0014] The degree of curvature at a point along the bending line 17 is determined by the ratio of the length of the truncation plane 162 to the length of the base 161 of adjacent elements 16 at that point. [0015] The degree of curvature will also depends on the thickness of the elements 16; a higher degree of curvature being obtained for thinner elements 16.

[0016] In an embodiment, each element 16 comprises a central opening 167 (see Fig. 12) such as to provide an internal lumen 26 extending within the succession of elements 16, along the catheter axis 100. The internal lumen 26 can allow the passage of a central guide or a balloon catheter, for example.

[0017] Fig. 5 represents a variant of the distal part 1 1 of Fig. 2 wherein the plurality of elements 16 comprise a straight element 168 having a rectangular shaped section. The straight element 168 does not topple when compressed against the adjacent elements 16 and the portion of the distal part 1 1 corresponding to the straight element 168 does not bend. Fig. 6 represents the distal part 1 1 wherein the elements 16 are compressed and the distal part 1 1 is bent. The portion of the distal part 1 1 comprising the straight element 168 is strait (it has a local degree of curvature being null). The length of the straight portion of the distal part 1 1 is determined by the width of the straight element 168. Alternatively, a straight portion of the distal part 1 1 can be obtained by using a plurality of straight elements 168. [0018] Fig. 7 illustrates the distal part 1 1 according to another

embodiment. The plurality of elements 16 comprise a first subset of elements 16' and a second subset of elements 16". The section 160 of each of the elements 16 in the first and second subsets 16', 16" has a shape of a truncated triangle such as in the example of Fig. 3. The elements 16 in the first subset 16' are arranged such that the base 161 of each element 16 is oriented on a first line 170 along the tubular hollow body 15. The elements 16 in the second subset 16" are arranged such that the base 161 of each element 16 is oriented on a second line 171 along the tubular hollow body 15, the second line 171 being angularly opposed to the first line 170 on the tubular hollow body 15.

[0019] When the elements 16 are compressed (see Fig. 8), the portion of the distal part 1 1 comprising the first subset of elements 16' bend in a first predetermined bending direction and the portion of the distal part 1 1 comprising the second subset of elements 16" bend in a second

predetermined bending direction that is opposed to the first

predetermined bending direction.

[0020] In an embodiment, the tubular hollow body 15 comprises a stiff portion 151 on the stretching side of the tubular hollow body 15 and a flexible portion 152 on the compressed side of the tubular hollow body 15. The stiff portion 151 can have a greater stiffness than the flexible portion 152 such that the stiff portion 151 can act as a return spring to unbend the distal part 1 1 once the elements 16 are not compressed.

[0021] In the example of Figs. 2 to 6, the tubular hollow body 15 comprises the stiff portion 151 along a line corresponding to the radial position of the base 161 and the flexible portion 152 elsewhere, or at least, along the bending line 17.

[0022] In the example of Figs. 7 and 8, the stiff portion 151 extends along the first line 170 on the portion of the distal part 1 1 comprising the first subset of elements 16' and along the second line 171 on the portion of the distal part 1 1 comprising the second subset of elements 16". The flexible portion 152 extends along the second line 171 on the portion of the distal part 1 1 comprising the first subset of elements 16' and along the first line 170 on the portion of the distal part 1 1 comprising the second subset of elements 16". [0023] In another embodiment, the catheter 10 comprises a steering assembly containing a first cable 20 extending from a distal end 1 10 of the distal part 1 1 towards the proximal part 12. The steering assembly is configured to tension the first cable 20 such as to compress the elements 16 against each other and bend the distal part 1 1 in the predetermined bending direction.

[0024] In Figs. 2 and 4, the first cable 20 extends on the side of the truncation plane 162 of the elements 16. In this configuration, tensioning the first cable 20 results in toppling the elements 16 on their narrow side (on the side of the truncation plane 162) and bend the distal part 1 1 in the predetermined bending direction.

[0025] The first cable 20 can be slacked such as to allow the elements 16 to be moved apart from each other such that the distal part 1 1 is no more bent. The stiff portion 151 can act as a return spring to unbend the distal part 1 1 along the catheter axis 100, once the first cable 20 has been slacked.

[0026] Each element 16 can comprise an opening 165 such as to allow the first cable 20 to pass through the opening 165 of each element 16 and extend from the distal end 1 10 towards the proximal part 12. In the example of Figs. 2 and 4, the first cable 20 is attached to the most distal element 18.

[0027] In the example of Fig. 7 and 8, the steering assembly comprises a second cable 21 extending from a most distal element 18' of the first subset 16' towards the proximal part 12. In this configuration, the tensioning of the first cable 20 allows for bending the portion of the distal part 1 1 comprising the second subset of elements 16" and the tensioning of the second cable 21 allows for bending the portion of the distal part 1 1 comprising the first subset of elements 16'. When slacking any of the first and second cable 20, 21, the distal part 1 1 can become aligned along the catheter axis 100 by the return action of the stiff portion 151 comprised along the portion of the distal part 1 1 comprising the first subset of elements 16' and along the portion of the distal part 1 1 comprising the second subset of elements 16".

[0028] In yet another embodiment shown in Fig. 9, the section of the elements 16 comprise has a shape of a biconvex lens. The convex lens shape allows for two adjacent elements 16 to pivot on each other when the elements 16 are compressed.

[0029] The steering assembly can comprise a first cable 20 and a second cable 21. Both cables 20, 21 can extend from the distal end 1 10 of the distal part 1 1 , for example by being attached to a most distal element 18, towards the proximal part 12. Tensioning the first cable 20 results in pivoting the elements 16 toward the left such as to bend the distal part 1 1 upward relative to the catheter axis 100 (see Fig. 10). Tensioning the second cable 21 results in pivoting the elements 16 toward the right such as to bend the distal part 1 1 downward relative to the catheter axis 100 (see Fig. 1 1).

[0030] In fact, the biconvex section of the elements 16 allows the distal part 1 1 to be bent in any predetermine bending direction around the catheter axis 100. The degree of curvature of the bent distal part 1 1 can be increased by increasing the number of elements 16 and/or by increasing the convexity of the element's 16 section.

[0031] The distal part 1 1 in the configuration of Figs. 9 to 1 1 can be bent in two opposite predetermined bending directions, possibly with a bending angle of 180°.

[0032] In a variant not shown, the distal part 1 1 comprising the elements having a truncated triangle shaped section 160 as in the example of Fig. 2 comprises a first cable 20 extending along the narrow truncation plane 162 and a second cable 21 extending along the large base 161. In such configuration, the traction on the first cable 20 brings the narrow truncation plane 162 of the elements 16 together and bend the distal part 1 1 in the predetermined direction. The traction on the second cable 21 can be used to brings the large base 161 of the elements 16 together such as to straighten the distal part 1 1 along the catheter axis 100.

[0033] In a variant, the elements 16 can comprise a cooperating member such that two adjacent elements 16 do not rotate around the catheter axis 100 in relation to each other. The cooperating member can also be configured to limit the degree of pivoting of the elements 16. In the example of Figs. 9 to 1 1 , the cooperating member comprises a protruding member 163 cooperating with a receiving groove 164 of the adjacent element 16. For example an element 16 can comprise one to four protruding member 163 cooperating with one or four receiving groove 164 of the adjacent element 16. The cooperating member allows for avoiding disorganized bending of the distal part 1 1.

[0034] In an embodiment shown in Fig. 12, the steering assembly comprises four cables 20 fixed to the most distal element 18 and extending towards the proximal end of the catheter 10. When the elements 16 have a biconvex lens shape, the tensioning any one of the four cables 20 allows for bending the distal part 1 1 in any predetermined bending direction.

[0035] Fig. 13 represents the shaft part 14 of the catheter 10 comprising canals extending along the shaft part 14, the canals 27 being configured for passing the cables 20. The shaft part 14 can comprises the same number of canal 27 as cable 20. In the example of Fig. 13, the canals 27 are comprised in an internal shaft 141 , coaxial with the shaft part 14.

[0036] The catheter disclosed herein can be bent in any direction around the catheter axis 100 without the need to rotate the catheter from its proximal part 12, for example when an arterial curve must be followed or a perpendicular ostium has to be entered. [0037] The proximal part 12 of the catheter 10 can comprises a hand- rotatable knob system 23 (see Fig. 1). The rotation of the knob system 23 applies a rotational torque in the desired direction to the proximal part 12, and to the entire catheter 10, such that the rotation is transmitted to the distal part 1 1. The proximal part 12 and the shaft part 14 have preferably a high torque. The catheter 10 can also be rotated by using a motor.

[0038] Rotating the catheter 1 allows orienting the bent distal part 1 1 in any suitable direction, even if the distal part 1 1 is configured to bend in only one predetermined bending direction, as in the configuration of Figs. 2 and 4.

[0039] Fig. 14 represent the steering assembly according to an

embodiment wherein the steering assembly comprises a gear train including a first toothed wheel 31 cooperating with a second toothed wheel 32 via a central toothed wheel 33. Depending on the sense of rotation of the first toothed wheel 31 a first cable 20 is wound or unwound on the first toothed wheel 31. The second toothed wheel 32 is driven in the opposite rotation direction than the one of the first toothed wheel 31 such that a second cable 21 is respectively unwound or wound on the second toothed wheel 32. Thus when the first cable 20 is tensioned (by being wound on the first toothed wheel 31) the second cable 21 is slacked and vice versa. The steering assembly of Fig. 14 is suitable for the catheter configuration of Figs. 9 to 1 1.

[0040] Fig. 15 represent the steering assembly according to another embodiment wherein the first cable 20 and the second cable 21 are attached to an asymmetrical (for example egg-shaped) pivoting cam 34. Again, the shape of the cam 34 allows to simultaneously tension the first cable 20 and slacken the second cable 21 , or vice versa, by pivoting the cam 34.

[0041] Fig. 16 shows the steering assembly according to yet another embodiment wherein the steering assembly comprises two cables 20, 21 and the gear train arrangement such as the one described in the configuration of Fig. 14. The steering assembly further comprises a pivoting shaft 35 pivoting about an axis 101 substantially perpendicular to the catheter axis 100. A third cable 28 and a fourth cable 29 are attached to the pivoting shaft 35 in a way that when the pivoting shaft 35 is pivoted the third cable 28 is tensioned while the fourth cable 29 is slackened, and vice versa, depending on the pivoting direction of the pivoting shaft 35. For example, the third and fourth cable 28, 29 can be attached on opposite side of the circumference of the pivoting shaft 35.

[0042] Fig. 17 shows the steering assembly according to yet another embodiment wherein the first cable 20 and the second cable 21 are attached to an asymmetrical pivoting cam 34 as described in the example of Fig. 15. The third and fourth cable 28, 29 are attached on a second cam 36 that pivots about an axis 101 substantially perpendicular to the catheter axis 100. In the particular example of Fig. 17, each of the two cables 28 and 29 are attached on opposite side of the second cam 36 via a stud 37. The pivoting shaft 35 in Fig. 16 and the second cam 36 in Fig. 17 can be pivoted via a knob 38. A knob (not shown) can also be used for pivoting the gear train 21, 32, 33 and the asymmetrical pivoting cam 34.

[0043] As shown in Figs. 16 and 17, the steering assembly can be comprised in a casing 39 such that, for example, only the knobs 38 are accessible from outside the casing 39. The casing 39 can comprise a cavity (not shown) extending along the catheter axis 100. The cavity can comprise successive guides, balloons and/or stent.

Reference Numbers

10 catheter

100 catheter axis

101 axis

1 1 distal part

1 10 distal end

12 proximal part

14 shaft part

141 internal shaft

15 tubular hollow body

151 stiff portion

16 element

16' first subset of elements

16" second subset of elements

160 section

161 base

162 truncation plane

163 protruding member

164 receiving groove

165 opening

166 lateral face

167 central opening

168 straight element

17 bending line

170 first line

171 second line

18 most distal element

20 cable, first cable

21 second cable

23 knob system

24 hollow canal

25 expandable dilation member

26 internal lumen

27 canal

28 third cable

29 fourth cable

31 first toothed wheel

32 second toothed wheel

33 central toothed wheel

34 asymmetrical cam

35 pivoting shaft

36 second cam

37 stud

38 knob

39 casing