Catheter comprising a rolling membrane and a transducer

Abstract

The present application relates to rolling membrane catheter comprising at least one transducer (e.g. a pressure wave generator). The application is further related to a method for treating calcified lesions in blood vessels using such a catheter.

Description

[0001] Catheter comprising a rolling membrane and a transducer

[0002] The present application relates to rolling membrane catheter comprising at least one transducer (e.g. a pressure wave generator). The application is further related to a method for treating calcified lesions in blood vessels using such a catheter.

[0003] The current shockwave instruments are too bulky to get into complex lesions. Then usually atherectomy is used and already does the job of preparing the lesion. However, Atherectomy devices are limited to be used in larger vessels as the specially used guidewire is too stiff to place in distal regions of lesion especially when the path becomes too tortuous. Atherectomy procedure requires a lot of training. In longer complex lesions the use of shockwave instruments becomes tedious due to the fact that the device needs to be placed, inflated, shockwaves applied, deflated several times. Both devices are very expensive and prevent widespread use.

[0004] In view of the plurality of drawbacks, there is a need for improving catheters to overcome at least some of these drawbacks.

[0005] The catheter of claim 1 comprising a rolling membrane may contribute to overcoming such drawbacks.

[0006] A catheter, preferably for treating calcified lesions in blood vessels, is described comprising a rolling membrane being adapted to roll out in a longitudinal direction from a rolled-in state into a rolled-out state and vice versa and the rolling membrane defining an inner volume that can be pressurized; wherein the catheter comprises an inner shaft and / or an outer shaft and wherein the catheter further comprises at least one transducer, optionally connected to an energy source (e.g. a power supply) and / or a control unit. The outer shaft may at least partially surround the inner shaft and the inner shaft may be slidably arranged within the outer shaft. A first end of the rolling membrane may be attached to a distal portion and / or a distal end of the inner shaft and a second end of the rolling membrane may be attached to a distal portion and / or a distal end of the outer shaft.

[0007] The catheter may further comprise an intermediate shaft being situated between the inner shaft and the outer shaft. The intermediate shaft may be axially displaceable.

[0008] The catheter may further comprise a dilatable balloon.

[0009] In one embodiment the dilatable balloon may be attached to the inner shaft. Such a catheter may be referred to hereinafter as rolling membrane catheter.

[0010] In another embodiment the dilatable balloon is attached between the distal end of the inner shaft and a distal end of the intermediate shaft. Such a catheter may be referred hereinafter to as a combined rolling membrane-balloon catheter.

[0011] The at least one transducer may be an electromagnetic wave emitter, a pressure wave generator and / or a mechanical wave generator. Pressure waves may be generated based on ultrasound waves, radio frequency waves, shock waves, laser excitation, mechanical waves or hydraulic waves. Thus, the at least on transducer may be an ultrasound wave generator, a radio frequency wave generator, a shock wave generator, a laser, a hydraulic pressure wave generator. The pressure waves generated by the pressure wave generator may be electromagnetic wave induced pressure waves (e.g. ultrasonic / ultrasound induced pressure waves, radio frequency induced pressure waves, microwave-induced pressure waves), laser induced pressure waves, electrically-induced pressure waves or mechanically induced pressure waves. The pressure waves may be pulsed pressure waves, e.g. pulsed hydraulic pressure waves (i.e. pulsed pressure waves guided through a liquid medium). The at least one hydraulic pressure wave generator may be a pulsed hydraulic pressure wave generator which is configured to generate hydraulic pulsed pressure waves.

[0012] As pulsed (hydraulic) pressure waves a series of pressure pulses, optionally interspersed with relaxation intervals, has to be understood. These pulsed (hydraulic) pressure waves are delivered through the rolling membrane positioned within an occlusion. Each (hydraulic) pressure pulse period may start with an initial minimum pressure magnitude and may end with a final maximum pressure magnitude. The pressure magnitude within each pulse period can either increase or vary, or it can remain constant at a single magnitude. Additionally, the duration of each pressure pulse period can progressively lengthen from an initial to a final pressure pulse period. The initial pressure pulse may be 5 bar and the pressure may be increased by 1 bar / s, preferably until the breakage of the occlusion occurs. The pressure waves could be pulsatile pressure waves starting at 5 to 10 bar pressure with 20 Hz, increasing by 1 bar / s to a maximum pressure of 15 to 25 for a defined period of time, for example 30s.

[0013] The at least one transducer (e.g. electromagnetic wave emitter, pressure wave generator and / or a mechanical wave generator) may not be arranged within the inner shaft. Preferably, the at least one hydraulic pressure wave generator may not be arranged within the inner shaft.

[0014] The at least one transducer, e.g. the at least one pressure wave generator, may be coupled to an energy source, preferably to a power supply.

[0015] The at least one transducer can be designed as transceiver. A transceiver can function both as a transmitter and a receiver. The at least one transducer can be shaped as a cylinder, a hollow cylinder and a disk. The at least one transducer may be a radio frequency (RF) transducer (emitting radio frequencies).

[0016] The at least one transducer, may be attached to the inner shaft, the balloon and / or the guiding element or rolling membrane. For example, transducer could be printed on the inner shaft, the balloon and / or the guiding element or rolling membrane.

[0017] The transducers are sized small enough that each individual transducers could be excited individually and do not take a huge amount of power for example through the wires which supply power to the transducers. The catheter may comprise flexible ultrasound, RF or other type of transducers. The at least one transducer, emitter and / or transmitter may be attached to the surface of the balloon or the inner shaft. The at least one transducer, may be printed on the surface of the balloon. Temperature sensors and wires also could be printed on the surface of balloon, on the inner shaft.

[0018] The energy source may be located external to a catheter body and transmitted via at least one wire or printed wires to the at least one transducer. Alternatively, the energy source may be integrated in the catheter body. Several transducers may be arranged in series or in parallel configuration or any other configuration depends on the application and needs. The distance between transducers and the number of transducers may be adjusted based on the need and the type of application. Each of the at least one transducer, may have individual power supply.

[0019] A guiding element comprising the at least one transducer (e.g. a separate transducer core) may be passed through the inner shaft (thus, is arranged at least partially within the inner shaft). Thus, the inner shaft may have an inner diameter which is larger than an outer diameter of the guiding element or any other devices which should be send through the inner shaft for example a (shockwave) balloon or a stent.

[0020] The rolling membrane comprising the at least one transducer, is used to break (deep) calcifications within a blood vessel (plaque, stenosis, CTO).

[0021] Thus, the catheter may further comprise a temperature sensor for measuring the temperature.

[0022] The catheter may further comprise a control unit that controls the temperature sensor and / or the at least one transducer (e.g. pressure wave generator)

[0023] The catheter may comprise at least one temperature sensor (close to the at least one transducer) to measure temperature and control the excitation of each transducer and be able to set optimum parameters. For example, reduce the time of excitation or excite one or few transducers simultaneously or etc. depending on the length or lesion or the level of calcification, a control system could take up the necessary adjustment. With the use of at least one temperature sensor and a feedback loop in a control unit the vessel adjacent to the at least one transducer can be maintained at a desired temperature for a selected period of time. The output of control unit maintains a selected energy at each transducer for a selected length of time. The power delivered to each transducer may be measured by the control unit and be adjusted individually.

[0024] In case of a combined rolling membrane-balloon catheter a double insulation is guaranteed as there are two material layers. The rolling membrane or the balloon may be filled with different fluids. This has the effect that the intensity of energy delivered to the sites via the transducer(s) could change depending on the characteristic of liquid especially. The thus released energy, can for example create shock waves, that propagate with different velocities creating an adjustable pressure wave in the surrounding medium. The rolling membrane or the balloon may be fillable with different fluids.

[0025] The term “distal” throughout the application may be understood as further apart from a physician manipulating the catheter. The term “proximal” throughout the application may be understood as being closer to the physician manipulating the catheter.

[0026] The second end of the rolling membrane may be attached to an outer side of the distal portion of the outer shaft but not to the distal end of the outer shaft. It is advantageous to mount the rolling membrane a few mm away from the distal end of the outer shaft so that the entire cross-sectional area of the rolling membrane is immediately available when inflating the rolling membrane from the rolled-in state into a rolled-out state.

[0027] The catheter may further comprise at least one pushing element which is connected to a proximal portion and a proximal end of the inner shaft and surrounds the proximal portion and the proximal end of the inner shaft. The pushing element may be a metal tube. The more rigid pushing element enables a higher pushability while at the same time the flexible inner shaft enables a flexible maneuvering at the patient’s side e.g. the blood vessel. The pushing element may have at its proximal end a pushing handle which enables a better pushing of the pushing element. The pushing element may have at its proximal end a pressure port for pressurizing and depressurizing the rolling membrane.

[0028] The pushing element may comprise a length measuring tool, preferably a ruler. A proximal portion and / or a proximal end of the outer shaft may be connected to a multiport handle. The multi-port handle comprising a first port for injecting a contrast medium and a second port for receiving the pushing element (with the inner shaft and optionally the guidewire arranged therein) or the intermediate shaft.

[0029] The inner shaft may comprise at least one radiopaque marker which is attached to the distal portion and / or the distal end of the inner shaft and wherein the outer shaft comprises at least one radiopaque marker which is attached to the distal end of the outer shaft. Having positional markers at least at the distal end of the inner shaft and at the distal end of the outer shaft enables a better control of whether the rolling membrane is in the rolled-in or rolled- out state. Preferably, the inner shaft may comprise at least one first radiopaque marker which is attached to the distal portion and at least one second radiopaque marker which is attached to the distal end of the inner shaft and wherein the outer shaft comprises at least one radiopaque marker which is attached to the distal end of the outer shaft. The first radiopaque marker and the second radiopaque marker are spaced apart in the longitudinal direction of the catheter The radiopaque marker may be an annular radiopaque marker.

[0030] The rolling membrane is connected pressure-tight with the outer shaft and inner shaft (e.g. by means of corresponding welds). The inner volume of the rolling membrane can be pressurized with a fluid. The fluid may be fed through a diaphragm pressure port. As the inner shaft has a smaller diameter it forms an annular space together with the outer shaft. The annular space is in fluid communication with the pressure port to be able to pressurize the rolling membrane with a fluid.

[0031] The fluid may be a contrast agent or a physiological saline solution. Using a contrast agent improves the visibility under X-rays and thus a better control of whether the rolling membrane is in the rolled-in or rolled-out state, especially in combination with the above described radiopaque markers. The fluid may be fed through pressure port comprising a diaphragm.

[0032] The rolling membrane may be adapted to roll in and out in a longitudinal direction of the catheter or a distal direction, preferably along a vessel of a patient, for example by at least one centimeter. A catheter with a rolling membrane to be rolled out in a distal direction along a blood vessel of a patient allows a friction reduced movement of a catheter along a blood vessel of a patient.

[0033] A rolling-out or rolling-in of the rolling membrane may be understood as a corresponding folding outwards or folding inwards of at least a (main) portion of the rolling membrane, e.g., in a longitudinal direction along a vessel of the patient. The rolling membrane may be folded inwards into itself. It may be possible that the rolling membrane is adapted to roll out by more than 10 cm, more than 20 cm, up to 30 cm or even up to 40 cm or more in a longitudinal direction.

[0034] The rolling membrane may be more flexible than the outer shaft. The rolling membrane may have a smaller wall thickness than the inner shaft and / or the outer shaft. The rolling membrane when being pressurized may be extendable in longitudinal direction at a higher extent than in the radial direction.

[0035] The rolling membrane may preferably be made from a flexible material for supporting a flexible folding of the rolling membrane inwards, thus supporting a rolling-in of the rolling membrane. The rolling membrane may be made of an organic polymer, preferably a (thermoplastic) elastomer. The rolling membrane may comprise a polyamide, preferably a polyamide-based elastomer; a polyether block amide, polyester; a polyester-based elastomer; a polyurethane, preferably a thermoplastic polyurethane; a polyolefin-based elastomer) and / or any other suitable material.

[0036] The partially rolled out rolling membrane may form a bubble for receiving a shockwave transmitting fluid. The bubble may comprise the shockwave transmitting fluid. A separate catheter or guiding element comprising a shock wave generator may be inserted into / situated the inner shaft lumen of the rolling membrane catheter.

[0037] The rolling membrane may be configured to dynamically shift its shape e.g. by transmitting an ondulating tensile force to the rolling membrane.

[0038] The rolling membrane may comprise a drug or is at least partially covered by a drug coating layer. A first end of the rolling membrane may be attached to a distal portion and / or a distal end of the inner shaft. The first end of the rolling membrane may be attached directly to (the material of) the distal portion and / or the distal end of the inner shaft. Alternatively, the first end of the rolling membrane may be attached indirectly to (the material of) the distal portion and / or the distal end of the inner shaft via a bonding material. For example, if the inner shaft is made of PEEK the rolling membrane may be attached to the distal portion and / or the distal end of the inner shaft via a polyamide (PA12) as a bonding material (because PEEK is not weldable). The bonding material may at the same time serve as the distal tip of the inner shaft.

[0039] The guidewire may be adapted to be slidable with respect to an inner side of the rolling membrane. The guidewire may be made of a radiopaque material. The guide wire may extend from a proximal end of the catheter to a distal end of the catheter (and optionally further in the distal direction along the blood vessel of the patient).

[0040] The inner shaft and / or the outer shaft may be reinforced, preferably by a polymer braid or by reinforcing fibers.

[0041] An outer diameter of the catheter may be the same or smaller than an inner diameter of a vessel to be inserted.

[0042] The inner shaft may comprise a (cone shaped) distal tip or may be connected to a (cone shaped) distal tip at its distal end. A cone shaped tip may support a simplified movement of the catheter along the distal direction (along the blood vessel of the patient). A cone shaped tip reduces the risk for complications arising from a rolling-in of the rolling membrane. This increases the safety of the usage of the catheter.

[0043] The (cone shaped) distal tip may be made from a different material than the inner and / or outer shaft. Alternatively, the distal tip and the rolling membrane may be made from the same material. The (cone shaped) distal tip may be an atraumatic tip. This risk for the inner wall of the blood vessel to be damaged may be reduced by an atraumatic distal tip. The atraumatic tip may advantageously contribute to a simplified movement of the rolling membrane catheter along the blood vessel of the patient by preventing damages / lesions caused to an inner wall of the blood vessel, even when the membrane is in a rolled-in state.

[0044] The atraumatic tip may comprise an elastomer. The elastomer may, e.g., be a thermoplastic elastomer. In some cases, the elastomer may be a thermosetting polymer. In some exemplary implementations, the elastomer may comprise a polyamide-based elastomer, a polyester- based elastomer, a polyolefin-based elastomer and / or any other suitable type of elastomer or plash c / polymer material. In some exemplary implementations, the atraumatic tip may be made from a combination of one or more of the aforementioned materials. The atraumatic tip may comprise a compressible material, preferably a polymeric foam. By providing the atraumatic tip such that it comprises an elastomer, the atraumatic tip may possess increased failure strain and may be deformed under strain and tension without rupturing. Moreover, a simplified and cost-effective manufacturing procedure, e.g., by means of thermoforming, of the atraumatic tip may be supported as a simplified shaping of the atraumatic tip comprising the elastomer may be facilitated. Moreover, elastomers may provide increased biocompatibility thus avoiding allergic reactions of the patient.

[0045] The (cone shaped and / or atraumatic) distal tip may comprise at least on radiopaque marker. The at least one radiopaque marker at the distal tip of the inner shaft or at the distal end of the inner shaft allows an improved positioning of the guidewire’s distal end either inside the inner shaft or outside the inner shaft.

[0046] The atraumatic tip may be provided with a maximum diameter which is smaller than a diameter of the outer shaft.

[0047] The atraumatic tip may be configured to receive a guide wire at a center region of the atraumatic tip.

[0048] The atraumatic tip may be formed by a portion of the rolling membrane. In some exemplary implementations, at least a distal portion, as seen in a rolled-in state, of the rolling membrane, may be adapted to not being fully folded inwards into itself (e.g., into an inner lumen of the rolling membrane) and may instead be adapted to at partially form the atraumatic tip.

[0049] By forming the atraumatic tip by a portion of the rolling membrane, a simplified catheter design may be facilitated (e.g., as less components need to be assembled) which may decrease manufacturing costs and recyclability of the catheter. In other examples, the rolling membrane may be adapted such that, in the fully retracted state, the distal portion of the rolling membrane is still rolled out. For example, the distal portion of the membrane may comprise an increased stiffness as compared to the remaining portion, e.g. as provided by thermoforming such as to form an atraumatic tip with a suitable resilience. Additionally or alternatively, a pressure in a predetermined range may be applied to the distal portion of the membrane such as to provide suitable resilience.

[0050] In some examples, the atraumatic tip may comprise a compressible material, preferably a plastic foam. Additionally or alternatively, the atraumatic tip may be adapted to be retractable via the inner lumen of the rolling membrane. For example, the atraumatic tip may be provided with an atraumatic tip shaft extending from the atraumatic tip to a proximal end of the catheter. The atraumatic tip shaft may be provided with a narrow inner lumen which may, e.g., encompass the guide wire. The atraumatic tip may then for example be retracted prior to rolling out the rolling membrane. Therefore, an obstacle free rolling-out of the rolling membrane may be ensured.

[0051] The rolling membrane may be adapted to move to a position distal to a position of the atraumatic tip when the rolling membrane is rolled out. Alternatively, the rolling membrane may be adapted not to move to a position distal to a position of the atraumatic tip when the rolling membrane is rolled out.

[0052] The multi-port handle may comprise a stopper and / or locking mechanism which is configured to avoid advancement of the rolling membrane in the longitudinal direction (further than a maximal permissible distal position) and / or rotation of the rolling membrane.

[0053] A kit comprising a catheter as described above and at least one pressure wave generator is described herein as well. The use of the catheter as described above for treating calcified lesions in blood vessels is described. However, the rolling membrane may be also used in any (neuro)vascular intervention, in neurology, in oncology, in ear, nose, and throat medicine, in endoscopy, in urology, gastroenterology, gynecology, pulmonology or in the nasolacrimal duct.

[0054] Also described is a method for treating calcified lesions in blood vessels using the catheter or the kit as described above comprising the steps of

[0055] - advancing the catheter (1) or the kit, optionally over a guidewire, towards the stenosis or the chronic total occlusion, and

[0056] - applying energy or pressure waves, e.g. shockwaves, radio frequency waves or ultrasonic waves, hydraulic pressure waves to the site to be treated.

[0057] There are three ways of treating a calcification like a chronic total occlusion (CTO):

[0058] 1) Placing a transducer in an inner shaft or an inner balloon or a rolling membrane of a catheter, bringing the catheter close to the calcification, activate the transducer to apply energy to the calcification, break the calcification (depending on the length of lesion and severity of the calcification change the energy in the transducers or / and repeat the roll in and roll-out of the rolling membrane as needed)

[0059] 2) using a rolling membrane catheter to penetrate or cross the lesion and introduce an external device like a guiding element or a pressure wave generator (e.g. shock wave generator).

[0060] 3) apply energy to the lesion and treat the lesion using a rolling membrane catheter and create a pressure pulse or wave in front of the rolling membrane to break the calcification.

[0061] In all the methods the vessel may be widened enough to allow a further treatment with another device e.g. a drug coated balloon or a stent.

[0062] Using at least one pressure pulse is one way to break a calcification. A pressure pulse may be created in the balloon itself by using a rolling membrane configuration as follows: When the operator pulls on the inner shaft the volume in the balloon is reduced with the ratio of the (balloon cross section minus outer shaft cross section) x displacement of the inner shaft. This will cause a sudden pressure increase. Since the excess contrast medium has not a place to go. The rising pressure is stored by elastic deformation inside the balloon membrane. A non-compliant balloon and shaft materials will cause stronger pressure rises than softer materials. The pressure pulse must not result in a plastic deformation of the balloon or shafts. Once the pressure pulse is built up, the inner shaft is proximally released and will be propelled forward by the energy stored in the balloon membrane and catheter shafts. This is similar to a rubber band that is set under tension and then is suddenly released (compare also the working mode of a crossbow). It might be necessary to flush the artery / stenosis with saline water as the pressure waves might destroy blood cells.

[0063] This type of motion has the advantage to create each time a pressure wave in front of the balloon while reducing the outer balloon diameter. For the next cycle, the inner shaft is pulled again and opens radially the stenosis with the balloon higher pressure to load the system for the next propelling forward.

[0064] This cycle can be repeated by a machine at a higher frequency, a distal generation of the inner shaft movement would be ideal to reduce abrasion and dampening by friction.

[0065] An actuator at the joint between balloon and inner shaft could be built as follows:

[0066] - the distal actuator might be based on known principles like shortening of nitinol spring induced by electrical current,

[0067] - a linear induction motor,

[0068] - by pulling on a spring that latches when a certain tension is exceeded,

[0069] - by a stack of piezo elements.

[0070] The method described above may not be limited to vascular interventions only but may also be used for other stenosis or narrowing in the human or animal body e.g. in in ear, nose, and throat medicine, in urology, gastroenterology, gynecology, pulmonology or in the bile duct.

[0071] The catheter may be used for treating calcified lesions in blood vessels. The catheter may be used in atherectomy or in intravascular lithotripsy. Intravascular lithotripsy is a method that fractures calcified lesions. Atherectomy is a peripheral intervention that opens arteries blocked by plaque.

[0072] The following figures are provided to support the understanding of the present invention:

[0073] Fig. 1 cross-sectional view of hybrid catheter with transducers located on an inner shaft;

[0074] Fig. 2 cross-sectional view of another hybrid catheter with transducers located on a guiding element;

[0075] Fig. 3 cross-sectional view of another hybrid catheter with transducers located on a balloon;

[0076] Fig. 4 cross-sectional view of double walled balloon with transducers located on an inner balloon;

[0077] Fig. 5 cross-sectional view of a rolling membrane catheter with transducers located on a guiding element in an inflated state;

[0078] Fig. 6 cross-sectional view of a rolling membrane catheter with transducers located on a guiding element in a state where the rolled in portion of the rolling membrane is inflated on its outside by a volume injected into the guiding element lumen;

[0079] Figs. 7A-7C Illustration of method steps of a method for crossing a stenosis or a chronic total occlusion;

[0080] Figs. 8A-8D Illustration of method steps of a method using a hydraulic pulsating rolling membrane.

[0081] Figs. 1 to 3 show a hybrid catheter of a rolling membrane catheter and balloon a catheter. The catheter comprises an outer shaft 1 and an inner shaft 4 which is axially displaceable therein. As shown in Figures 1 to 3, the catheter has an elongated outer shaft 1 having a distal end 2 with which it may be inserted into a bodily vessel, and a proximal end 3. An inner shaft 4 situated in the outer shaft 1 may have a smaller diameter than the outer shaft, and accordingly together with the outer shaft 1 forms an annular space 5. Situated in the inner shaft 4 is a lumen (not illustrated), by means of which the catheter may be pushed via a pushing element (e.g. a guidewire) to the treatment site in a bodily vessel. An intermediate shaft 7 is situated between the inner shaft 4 and outer shaft 1 which is likewise axially displaceable. In addition, an intermediate shaft 7 is coaxial with the two shafts 1, 4, and together with the inner shaft 4 may be axially displaced with respect to the outer shaft 1.

[0082] The intermediate shaft 7 is displaceable in a ring seal 8 in the form of a so-called Tuohy Borst seal, for example, which proximally closes off the annular space 5 in a pressure-tight manner. The inner shaft 4, in turn, is guided in a pressure-tight manner through an end plug 9 at the proximal end 10.

[0083] The catheter comprises a rolling membrane 12 which is attached (in a pressure-tight manner) between the distal end 2 of the outer shaft 1 and the distal end 11 of the inner shaft 4. The rolling membrane may be displaced between rolled-in state within the outer shaft 1 and a rolled-out state which is distally expanded from the outer shaft 1 by the action of pressure.

[0084] Figures 1 to 3 illustrate the rolling membrane in a position that is already slightly pushed out from the outer shaft 1. The rolling membrane 12 is connected in a pressure-tight manner to the outer shaft 1 and the inner shaft 2 by means of appropriate welds, and via the annular space 5 may be acted on by a pressurized fluid which may be introduced under pressure through the membrane diaphragm pressure port 13 at the proximal end 3 of the outer shaft 1.

[0085] The catheter further comprises a dilatable balloon 14 which is attached (in a pressure-tight manner) between the distal end 11 of the inner shaft 4 and the distal end of the intermediate shaft 7, and which may be displaced between a passive position within the outer shaft 1 and proximally in front of the rolling membrane 12 on the one hand, and an active position which is distally expanded from the outer shaft 1, within the rolling membrane 12, by the action of pressure on the other hand. The balloon 14 is proximally situated within the outer shaft 1, in front of the rolling membrane 12, and the distal cone 15 of the balloon is attached to the distal end 11 of the inner shaft 4 in a pressure-tight manner. The proximal cone of the balloon 14 in turn is mounted on the distal end 17 of the intermediate shaft 7 in a pressure-tight manner. Via the annular space 18 which is formed between the inner shaft 4 and the intermediate shaft 7, the balloon 14 may be acted on by a pressurized fluid which may be introduced through a balloon pressure port 19 at the proximal end 10 of the intermediate shaft 7.

[0086] In Fig. 1 the at least one transducer 16 (e.g. a pressure wave generator) is located on the inner shaft 4.

[0087] In Fig. 2 the at least one transducer 16 (e.g. a pressure wave generator) is located on a guiding element 6.

[0088] In Fig. 3 the at least one transducer 16 (e.g. a pressure wave generator) is located on the surface of the balloon 14.

[0089] Fig. 4 shows a detailed view of the balloon 14 of Fig. 3 having a further balloon 20 situated inside the balloon 14, wherein the at least one transducer 16 (e.g. a pressure wave generator) is located on the surface of the further balloon 14.

[0090] Figs. 5 to 6 show an example of a combination of guiding element 60 with transducer 80 (e.g. a pressure wave generator) and a rolling membrane catheter 100 with a rolling membrane 120 in a partially rolled-out state. In Fig. 6 the still rolled-in portion of the rolling membrane 130 is inflated (on its outside surface) by a fluid injected into the inner volume of the rolling membrane, so that the still rolled-in membrane 130 is inflated and approaches the diameter of the rolled out rolling membrane 120. The fluid (e.g. liquid) injected into the guiding element lumen will not escape at the tip of the rolling membrane as long as there is pressure in the rolling membrane 120 and the guiding element must not leak itself. The volume contained between the rolling membrane already rolled-out 120 and still rolled-in 130 is reduced at the same rate as its added into the space confined by the rolled-in membrane 130 and the guiding element lumen 60. The transducers 80 are not inside the rolling membrane balloon 120 and 130 but are inside a bubble formed by the rolling membrane in its partially rolled out state. The fluid (e.g. liquid) injected into the catheter guiding element lumen to build the bubble must be biocompatible.

[0091] The catheter 100 comprises an outer shaft 60 and an inner shaft 40. The outer shaft 110 at least partially surrounds the inner shaft 40. Thus, the outer shaft 110 has a larger diameter than an outer diameter of the inner shaft 40. As the inner shaft 40 has a smaller diameter it forms an annular space together with the outer shaft 110. The annular space is in fluid communication with the pressure port (not shown) to be able to pressurize the rolling membrane 120 with a fluid. The outer shaft 110 can be inserted into a patient’s vessel with its distal end whereas and its proximal end is always located outside the patient. Thus, the outer shaft 110 has an outer diameter which is smaller than the patient’s vessel.

[0092] The catheter 100 may further comprises a pushing element, e.g. a metal rod (not shown), which is firmly connected to a proximal portion and / or proximal end of the inner shaft. The pushing element, e.g. a metal rod, partially surrounds the proximal portion and / or the proximal end of the inner shaft 40. The inner shaft 40 and the pushing element are slidably arranged within the outer shaft 110. Thus, the pushing element can be moved axially with the inner shaft in relation to the outer shaft 110. The pushing element may have at its proximal end a pushing handle (not shown). The pushing element and / or the pushing handle comprise at its proximal end a through hole for the guiding element 60 (e.g. guidewire). The inner shaft 40 may have an inner shaft lumen 50 for a guiding element 60. The inner shaft 40 is made from a more flexible material than the pushing element.

[0093] The rolling membrane 120 forms an inner volume 121 and comprises a first end and a second end. The first end of the rolling membrane 120 is attached to a distal portion and / or a distal end of the inner shaft 40 and the second end of the rolling membrane 2 is attached to an outer side of a distal portion of the outer shaft 110. The rolling membrane is adapted to roll out in a longitudinal direction from a rolled-in state into a rolled-out state when being pressurized and / or when the pushing element is moved in a distal direction. The rolling membrane therefore defines an inner volume that can be pressurized.

[0094] The catheter comprises a guiding element 60 (e.g. guidewire) which is at least partially and slidably arranged within the inner shaft 40. The catheter can be pushed over the guidewire to the therapy site in a patient’s body e.g. blood vessel.

[0095] A proximal portion and / or a proximal end of the outer shaft 110 may be connected to a multiport handle (not shown). The multi-port handle comprises a first port for a contrast agent and a second port for receiving the pushing element with the inner shaft and the guidewire arranged therein. The pushing element may be sealed against a multiport handle via a sliding annular seal in a pressure-tight manner, for example in the form of a so-called "Tuhoy Borst" seal.

[0096] The rolling membrane is connected pressure-tight with the outer shaft 110 and the inner shaft 40 (e.g. by means of corresponding welds) and the inner volume 121 of the rolling membrane 2 can be pressurized via a fluid. The fluid may be fed through a diaphragm pressure port (not shown) which is situated at the proximal end of the pushing element and / or the pushing handle.

[0097] In Fig. 5 the at least one transducer 80, preferably shockwave electrodes, radio frequency electrodes or ultrasonic electrodes, is located on a guiding element 60.

[0098] The catheter shown in Fig. 6 shows a partially rolled-in membrane 130. In Fig. 6 the at least one transducer 80, preferably shockwave electrodes, ultrasound electrodes or radio frequency electrodes, is located on a guiding element 60.

[0099] Fig. 7 A-C illustrate method steps of a method for treating calcified lesions in blood vessels comprising the steps of a) advancing the catheter comprising a rolling membrane 120 and inner shaft 40 without a guidewire or over a guidewire 60 towards the stenosis or the chronic total occlusion, b) optionally penetrating or crossing through the stenosis or a chronic total occlusion with the guidewire 60, c) increasing the pressure in the inner volume of the rolling membrane d) introducing a guiding element comprising at least one transducer 80 (e.g. pressure wave generator) e) applying a hydraulic pressure wave, shockwave, a radio frequency wave or ultrasonic wave to the calcified lesion.

[0100] Figs. 8A-8D illustrates method steps of a method for crossing a stenosis or a chronic total occlusion using hydraulic Pulsation of the rolling membrane. This would cause propagation of several existing cracks instead of failure of only the largest crack. The shock waves propagate also in front of the balloon, if the inner shaft is suddenly released. A cyclical pulling back of the inner shaft of the rolling membrane catheter, reduces the distal volume inside the rolling membrane and would cause pressure pulses inside the balloon. Thus, Fig. 8A-8D show a pulsating rolling membrane. Fig. 8D shows the two states of the rolling membrane in overlay when applying an ondulating tensile force via the inner shaft. As consequence the balloon shape will switch from larger / shorter balloon shape to a smaller / longer balloon shape and that a very high frequency.

[0101] List of reference signs

[0102] 1 outer shaft

[0103] 2 distal end outer shaft

[0104] 3 proximal end outer shaft

[0105] 4 inner shaft

[0106] 5 outer shaft lumen

[0107] 6 guiding element

[0108] 7 intermediate shaft

[0109] 8 seal

[0110] 9 end plug

[0111] 10 proximal end inner shaft

[0112] 11 distal end inner shaft

[0113] 12 rolling membrane

[0114] 13 diaphragm pressure port

[0115] 14 balloon

[0116] 15 distal balloon cone

[0117] 16 transducer / pressure wave generator

[0118] 17 distal end intermediate shaft

[0119] 18 inner shaft lumen

[0120] 19 pressure port

[0121] 20 further balloon

[0122] 40 inner shaft

[0123] 50 inner shaft lumen

[0124] 60 guiding element

[0125] 70 intermediate shaft

[0126] 80 transducer / pressure wave generator

[0127] 90 balloon

[0128] 100 catheter

[0129] 110 outer shaft

[0130] 120 rolled-out portion of the rolling membrane

[0131] 121 inner volume of rolling membrane

[0132] 130 rolled-in portion of the rolling membrane

[0133] 200 catheter

Claims

Claims1. A catheter (100), preferably for treating calcified lesions in blood vessels, comprising a rolling membrane (12) being adapted to roll out in a longitudinal direction from a rolled-in state into a rolled-out state and vice versa and the rolling membrane (12) defining an inner volume that can be pressurized; wherein the catheter further comprises an inner shaft (4) and / or an outer shaft (1) and at least one transducer (16), and optionally a guiding element (6), wherein the at least one transducer is an ultrasound wave generator, a radio frequency wave generator, a shock wave generator, a laser or a hydraulic pressure wave generator.

2. The catheter (100) of claim 1, wherein the at least one hydraulic pressure wave generator is configured to generate hydraulic pulsed pressure waves.

3. The catheter (100) of claim 1 or 2, wherein the catheter (100) further comprises a dilatable balloon (14).

4. The catheter (100) according to claim 1 or 3, wherein the catheter (100) further comprises an intermediate shaft (7) being situated between the inner shaft (4) and the outer shaft (1), wherein the intermediate shaft (7) is axially displaceable.

5. The catheter (100) of claim 3, wherein the dilatable balloon (14) is attached to the inner shaft (4).

6. The catheter (100) according to claim 4, wherein the dilatable balloon (14) is attached between the distal end (11) of the inner shaft (4) and a distal end of the intermediate shaft (7).

7. The catheter (100) according to any one of the preceding claims, wherein the at least one transducer (16) is attached to the inner shaft (4), the rolling membrane (12), the balloon (14) and / or the guiding element (6).

8. The catheter (100) according to any one of the preceding claims, wherein at least a part of the transducer (16) was printed on the inner shaft (4), the rolling membrane (12), the balloon (14) and / or the guiding element (6).

9. The catheter (100) according to any one of the preceding claims, wherein the at least one transducer (16) is coupled to an energy source, preferably to a power supply.

10. The catheter (100) according to any one of the preceding claims, wherein the catheter (100) further comprises at least one temperature sensor for measuring the temperature of the transducer (16).

11. The catheter (100) according to any one of the preceding claims, wherein the catheter further comprises a control unit that controls the at least one temperature sensor and / or the at least one transducer (16).

12. The catheter (100) according to any one of the preceding claims, wherein the outer shaft (1) at least partially surrounds the inner shaft (4), and wherein the inner shaft (4) is slidably arranged within the outer shaft (1) and wherein a first end of the rolling membrane (12) is attached to a distal portion and / or a distal end of the inner shaft (4) and a second end of the rolling membrane (12) is attached to a distal portion and / or a distal end of the outer shaft (1).

13. The catheter (100) according to any one of the preceding claims, wherein the transducer is not arranged within the inner shaft.

14. The catheter (100) according to any one of the preceding claims, for use in crossing a stenosis or a chronic total occlusion, for use in atherectomy or in intravascular lithotripsy.

15. A method for treating calcified lesions in blood vessels using the catheter (100) of any of the claims 1 to 13 comprising the steps of- advancing the catheter (100) towards the stenosis or the chronic total occlusion, and- directing pressure waves to the site to be treated.

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