Abstract
An ultrasonic device for treatment of atherosclerosis. The device includes a sonotrode, a transmission wire and a tip, said sonotrode comprising a transducer and a horn, the transducer being coupled to the horn. The transmission wire is coupled on one end with the horn and on the opposite end with the tip, so that when the transducer vibrates, said vibration are amplified by the horn and transmitted to the transmission wire that displaces accordingly, said displacements of the wire inducing vibrations of the tip generating an acoustic field from said tip. The device comprises n sonotrode, n transmission wire, and at least one tip, n being superior or equal to two. The device further comprises a control module being arranged for controlling the amplitude of displacement of each transmission wire so as to set up the emitted acoustic field generated from said tip.
Claims
1. Ultrasonic device for generating an acoustic field in a lumen of a component of a cardiovascular system of a patient, in particular a blood vessel or a heart chamber, the device comprising a sonotrode, a transmission wire and a tip, said sonotrode comprising a transducer and a horn, the transducer being coupled to the horn, the transmission wire being coupled on one end with the horn and on an opposite end with the tip, so that when the transducer vibrates, said vibrations are amplified by the horn and transmitted to the transmission wire that displaces accordingly, said displacements of the transmission wire inducing vibrations of the tip generating an acoustic field from said tip, characterized in that the device comprises n sonotrodes, n transmission wires, and at least one tip, n being superior or equal to two, and in that the device further comprises a control module being arranged for controlling an amplitude of displacement of each transmission wire so as to set up an emitted acoustic field generated from said tip.
2. Ultrasonic device according to claim 1, wherein the device comprises m sonotrodes, m transmission wires, and one single tip, all the transmission wire being coupled to said tip, m being superior or equal to two.
3. Ultrasonic device according to claim 1, wherein the device comprises n sonotrodes, n transmission wires and n tips, each sonotrode being coupled to one transmission wire and one tip, n being superior or equal to two.
4. Ultrasonic device according to claim 1, wherein the device comprises n sonotrodes, n transmission wires and a maximum of n−1 tips, n being superior or equal to two, so that at least two of the n transmission wires are connected to a same of said n−1 tips.
5. Ultrasonic device according to claim 1, wherein the transducers of said sonotrodes are placed outside a lumen of a component of a cardiovascular system of a patient when said tip is positioned within said lumen.
6. Ultrasonic device according to claim 1, wherein the control module controls a power supply provided to each sonotrode to control the amplitude of displacement of each transmission wire.
7. Ultrasonic device according to claim 1, wherein the control module allows setting up the emitted acoustic field in two dimensions defined in a plane.
8. Ultrasonic device according to claim 1, wherein the control module allows setting up the emitted acoustic field in three dimensions defined in a space.
9. Ultrasonic device according to claim 1, wherein the control module is arranged for providing one or both of a symmetrical emitted acoustic field and an asymmetrical emitted acoustic field.
10. Ultrasonic device according to claim 1, wherein the control module is arranged for setting up at least one of an intensity and an orientation of the emitted acoustic field.
11. Ultrasonic device according to claim 1, wherein a center of the tip is free from transmission wire, said center of the tip further comprises a traversing hole for passing a guidewire.
12. Ultrasonic device according to claim 1, wherein the tip has a shape chosen among spherical shape, hemispherical, spherical with lobes fixed thereon, ovoid with a cavity, cylindrical with a cavity in a body thereof, or cylindrical.
13. Ultrasonic device according to claim 1, wherein the tip has a maximal diameter comprised between 0.5 mm and 5 mm.
14. Ultrasonic device according to claim 1, wherein the transducer is one of a piezoelectric transducer and a magnetostrictive material.
15. Ultrasonic device according to claim 1, the device further comprising a power generator for supplying energy to said sonotrodes.
16. Ultrasonic device according to claim 1, wherein each sonotrode is supplied with a power comprises between 5 and 300 watts.
17. Ultrasonic device according to claim 1, wherein each transmission wire is received in a catheter, said tip exiting the catheter.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] 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:
[0052] FIG. 1 shows a view of an existing device of the prior art;
[0053] FIGS. 2A through 6A show a first embodiment of the device according to the invention;
[0054] FIG. 6B shows a second embodiment of the device according to the invention;
[0055] FIG. 7 shows the tip of the device according to the first and second embodiments;
[0056] FIGS. 8A, 8B, and 9 show the distribution of the acoustic field of the tip of the device according to the first embodiment;
[0057] FIG. 10 shows the evolution of the angle of the maximum of the absolute pressure generated from the tip in the first embodiment of the device according to the invention;
[0058] FIG. 11A shows a third embodiment of the device according to the invention;
[0059] FIG. 11B shows a fourth embodiment of the device according to the invention;
[0060] FIG. 12 shows the tip of the device according to the third and fourth embodiments;
[0061] FIGS. 13A, 13B, and 14 show the distribution of the acoustic field of the tip of the device according to the third embodiment;
[0062] FIG. 15 shows the evolution of the angle of the maximum of the absolute pressure generated from the tips in the third embodiment of the device according to the invention;
[0063] FIG. 16 shows a fifth embodiment of the device according to the present invention;
[0064] FIGS. 17A and 17B shows the distribution of the acoustic field of the tip of the device according to the fifth embodiment;
[0065] FIG. 18 shows the control module of the device according to the first and third embodiments of the device according to the invention; and
[0066] FIGS. 19A through 19F shows various embodiments of the tip of the device according to the invention.
DETAILED DESCRIPTION OF THE FIGURES
[0067] FIGS. 2A through 19F represent several embodiments of the present invention, but the invention is not limited to the disclosed embodiments.
[0068] FIG. 6A represents a device 10a according to a first embodiment. In this embodiment, the device 10a comprises power generator 11 providing electrical energy to the device 10a. The device 10a further comprises two sonotrodes 12 a,b, each sonotrode 12 a,b being connected to one transmission wire 13 a,b. In this embodiment, all the transmission wires 13a,b are connected to the same single tip 14. Each sonotrode 12a,b comprises one transducer 15a,b that is connected to a horn 16a,b.
[0069] In this first embodiment, the transducers 15a,b are PZT stack. The transmission wires 13a,b have a diameter of 0.5 mm and the tip 14 have a diameter of 2 mm. The tip 14 and the wire 13a,b are made with TiAl.sub.6V.sub.4 but the invention is not limited to this material, for instance Aluminium could also be used.
[0070] The control module 17 allows controlling the electrical energy provided to each transducer 15a,b of each sonotrode 12a,b to set up the emitted acoustic field 18.
[0071] FIG. 6B represents a device 10b according to a second embodiment of the disclosure. The device 10b includes some of the same components and attributes as the device 10a, some of which are identified by same-labeled reference characters. As with device 10a, the device 10b comprises power generator 11 providing electrical energy to the device 10b. However, the device 10b comprises only one sonotrode 12a, which is connected to one transmission wire 13a. The second wire 13b is mechanically fixed to an anchor point 21, for example, by clamping, pinning, screwing or welding to a frame (not depicted) that supports the sonotrode 12a or a housing (not depicted) that houses the sonotrode 12a. The mechanically fixed anchor point 21 holds the wire 13b in fixed relationship with the point of rest Rat the tip 14, thereby effecting the motion and emitted acoustic field F4 described at FIGS. 5A and 5B.
[0072] The device 10a can also be made to function as depicted in FIGS. 5A and 5B. By not powering sonotrode 12b of device 10a, the effect is the same as mechanically fixing the transmission wire 13b. Herein, to “energize” a sonotrode is to supply the sonotrode with an alternating voltage or current. Accordingly, a sonotrode is “not energized” when no voltage or current is supplied, or when a DC voltage or current is supplied.
[0073] For the devices 10a and 10b, wires 13a,b are connected to a single tip 14. The transducers 15a,b are PZT stacks. The transmission wires 13a,b have a diameter of 0.5 mm and the tip 14 have a diameter of 2 mm. The tip 14 and the wire 13a,b are made with TiAl.sub.6V.sub.4 but the invention is not limited to this material, for instance Aluminium could also be used.
[0074] The control module 17 allows controlling the electrical energy provided to each transducer 15a,b of each sonotrode 12a,b to set up the emitted acoustic field 18.
[0075] FIG. 7 shows the tip 14 of the devices 10a and 10b. The tip 14 comprises two blind holes 19 design for receiving the transmission wires 13a,b. The tip 14 further comprises a traversing hole 20 for passing a guidewire (not represented in the figures).
[0076] FIGS. 8A, 8B, and 9 represent the distribution of the acoustic field 8 in operation for the first embodiment.
[0077] FIG. 8A represents a case where the each wire receive the amount of energy from the control module 17, to provide the same amplitude of displacement on the wires and where the wires oscillate in phase. The emitted acoustic pressure 8 is symmetrical and centered around an axis parallel to the longitudinal axis of the transmission wires 13a,b.
[0078] FIG. 8B represents a case where there is a ratio of ten (10) between the transmission wire 13a,b, said ratio being induced by the control module 17. In other words, the amplitude of displacement along the longitudinal axis of one transmission wire 13a is 50 microns, whereas the other transmission wire 13b is 5 microns and where the wires oscillate in phase. Consequently the emitted acoustic field 8 is asymmetric and oriented toward the transmission wire with the larger displacement. By selecting the wire on which a difference of amplitude is applied, it is possible to orient and to control in the plane (XY) the asymmetry of the acoustic field. In this embodiment, it is possible, when the device is placed in a vessel, to position the emitted acoustic field for instance toward a side of the vessel, to provide a major contribution of the acoustic field on the side of the vessel, and a minor contribution on the other side of the vessel. This can improve the treatment of an eccentric lesion by increasing the efficiency of the treatment on the area of the vessel where the treatment is needed and to protect, by limiting the acoustic field, the area where the treatment is not necessary.
[0079] FIG. 9 represents a case where each wire oscillates in opposition of phase (180° phase shift), with a displacement around the point of rest. The control module 17 ensures that each transmission wire receives the amount of energy to provide the same amplitude of displacement but the control module 17 induces a phase shift of 180°. As shown in FIG. 9, the emitted acoustic field is divided in two main contributions each oriented toward the side of the vessel when the tip 14 is placed in a vessel. Therefore, in this embodiment, it is possible to target occlusion located on both sides of the vessel and to improve the treatment of complex eccentric lesions.
[0080] FIG. 10 represents the angle of the maximum absolute pressure point on the tip distal face depending on the amplitude ration between the transmission wires. The plot shows that at a ratio of 10, it is possible to shift maximum pressure point 18° with respect to the position of said maximum pressure point when the ratio is 1. Therefore, this plot demonstrates that it is possible to control the shape (i.e., the orientation) of the emitted pressure field by controlling the relative displacement of the transmission wires of the device. This plot also demonstrates that this behavior (i.e., the orientation of the maximum absolute pressure point) is not impacted by the initial choice of the amplitude of displacement applied on the wires (as example 100 microns instead of 50 microns), but only by the choice of the amplitude ratio between the transmission wires. On the other hand, the intensity of the field is dependent on the choice of the amplitude of displacement. Greater displacement amplitude induces a higher max pressure value.
[0081] FIG. 11A represents a third embodiment of the device 100a. In this embodiment, the device 100a comprises power generator 101 providing electrical energy to the device 100a. The device 100 further comprises three sonotrodes 102a,b,c each sonotrode 102a,b,c being connected to a transmission wire 103a,b,c that leads to a tip 104 at the distal end of said transmission wire 103a,b,c. The three transmission wires 103a,b,c are connected to the same tip 104. Each sonotrode 102a,b,c comprises a transducer 105a,b,c that is connected to a horn 106a,b,c.
[0082] In this third embodiment, the transducers 105a,b,c are PZT stack. The transmission wires 103a,b,c have a diameter of 0.5 mm and the tip 104 have a diameter of 2 mm. The tip 104 and the wire 103a,b,c are made with TiAl.sub.6V.sub.4 but the invention is not limited to this material, for instance Aluminium could also be used.
[0083] The device 100a further comprises a control module 107 arranged for controlling the amplitude of displacement of the transmission wires 103a,b,c along the longitudinal axis. The amplitude of displacement of the transmission wire 103a,b,c depends on the energy supply provided to by the power generator 101 to the transducers 105a,b,c. The amplitudes of vibrations of the PZT stack is correlated to the electrical energy provided by the power generator. In the present embodiment, the control module 107 allows controlling the electrical energy provided to each transducer 105a,b,c of each sonotrode 102a,b,c to set up the emitted acoustic field 108.
[0084] FIG. 11B represents a device 100b according to a fourth embodiment of the disclosure. The device 100b includes some of the same components and attributes as the device 100a, some of which are identified by same-labeled reference characters. As with device 100a, the device 100b comprises power generator 101 providing electrical energy to the device 100b. However, the device 100b comprises only two sonotrodes 102a,b which are connected to transmission wires 103a,b respectively. The third wire 103c is mechanically fixed to an anchor point 111, for example, by clamping, pinning, screwing or welding to a frame (not depicted) that supports the sonotrode 102a,b, or a housing (not depicted) that houses the sonotrode 102a,b. The mechanically fixed anchor point 111 holds the wire 103c in fixed relationship with the point of rest of the tip 104. The resultant effect is a motion and emitted acoustic field akin to that described at FIGS. 5A and 5B.
[0085] The device 100a of FIG. 11A can also be made to function as depicted in FIGS. 5A and 5B. By not energizing sonotrode 102c of device 100a, the effect is the same as mechanically fixing the transmission wire 103c.
[0086] For devices that utilize three or more sonotrodes, the number of wires 103 that are mechanically fixed or not energized is not limited to a single sonotrode. Rather, the number of wires 103 that are mechanically fixed or not energized may range from 1 to n−1, where n is the total number of wires 103 connected to the tip 104.
[0087] FIG. 12 illustrates the tip 104 of the device 100 according to the third and fourth embodiments. The tip 104 comprises three blind holes 109 design for receiving the transmission wires 103a,b, c. The tip 104 further comprises a traversing hole 110 for passing a guidewire (not represented in the figures).
[0088] FIGS. 13A, 13B, and 14 represent the distribution of the acoustic field 108 in operation for the third embodiment.
[0089] FIG. 13A represents a case where the each wire receive the amount of energy from the control module 107 to provide the same amplitude of displacement on the wires, and where the wires oscillate in phase. The emitted acoustic pressure 108 is symmetrical and centered around an axis parallel to the longitudinal axis of the transmission wires 103a,b, c.
[0090] FIG. 13B represents a case where there is a ratio of ten (10) between the transmission wires 103a,b,c said ratio being induced by the control module 107. In particular, two transmission wires receive the amount of energy to provide the same amplitude of displacement on each one, the third one receive an amount of energy to provide an amplitude of displacement ten (10) times less than the two others transmission wires. In other words, the amplitude of displacement along the longitudinal axis of two transmission wires 103a,b is 50 microns, whereas the other transmission wire 103c is 5 microns, and where the three wires oscillate in phase. Consequently the emitted acoustic field 108 is asymmetric and oriented toward the transmission wires with the larger displacement. By selecting the wires on which a difference of amplitude is applied, it is possible to orient and to control in the space (XYZ) the asymmetry of the acoustic field. In this embodiment, it is possible when the device is placed in a vessel, to position the emitted acoustic field for instance toward a side of the vessel, to provide a major contribution of the acoustic field on the side of the vessel, and a minor contribution on the other side of the vessel. This can improve the treatment of an eccentric lesion by increasing the efficiency of the treatment on the area of the vessel where the treatment is needed and to protect, by limiting the acoustic field, the area where the treatment is not necessary.
[0091] FIG. 14 represents a case where one wire oscillates in opposition of phase (180° phase shift) of the two others, with a displacement around the point of rest. The control module 107 ensure that each transmission wire receives the amount of energy to provide the same amplitude of displacement on each wire but the control module 107 induces a phase shift of 180° between one of the wire and the two others. As shown in FIG. 14, the emitted acoustic field is divided in two main contributions. By selecting the wire on which the phase shift is applied, it is possible to orient in the space (xyz) these two contributions. Therefore, in this embodiment, it is possible to target occlusion located on both sides of the vessel and to improve the treatment of complex eccentric lesions.
[0092] FIG. 15 represents the angle of the maximum absolute pressure point on the tip distal face depending on the amplitude ration between the transmission wires. The plot shows that a ratio of 10, it is possible to shift maximum pressure point of 60° with respect to the position of said maximum pressure point when the ratio is 1. Therefore, this plot demonstrate that it is possible to control the shape (i.e., the orientation) of the emitted pressure field by controlling the relative displacement of the transmission wires of the device. This plot demonstrates also that this behavior (i.e. the orientation of the maximum absolute pressure point) is not impacted by the initial choice of the amplitude of displacement applied on the wires (as example 100 microns instead of 50 microns), but only by the choice of the amplitude ratio between the transmission wires. On the other hand, the intensity of the field is dependent on the choice of the amplitude of displacement. Greater displacement amplitude induces a higher max pressure value.
[0093] A fifth embodiment of the device is represented in FIG. 16. In this embodiment, the device 200 comprises power generator 201 providing electrical energy to the device 200. The device 200 further comprises two sonotrodes 202a,b each sonotrode 202a,b being connected to a transmission wire 203a,b that leads to a tip 204a,b at the distal end of said transmission wire 203a,b. In this embodiment, each transmission wire 203a,b is connected to one tip 204a,b. Each sonotrode 202a,b comprises a transducer 205a,b that is connected to a horn 206a,b.
[0094] In this fifth embodiment, the transducers 205a,b are PZT stacks. The transmission wires 203a,b have a diameter of 0.5 mm and the tip 204a,b have a diameter of 0.9 mm. The tips 204a,b and the wires 203a,b are made with TiAl.sub.6V.sub.4 but the invention is not limited to this material, for instance Aluminium could also be used.
[0095] FIGS. 17A and 17B represent the shape of the acoustic field of the device according to the fifth embodiment in operation. In FIG. 17A, both sonotrodes 202a,b received the amount of electrical energy from the control module 207, to provide the same amplitude of displacement on the wires and where the wires oscillate in phase so that the acoustic fields generated from the tips 204a, b are similar. Therefore, each sonotrode 202a,b contributes equally to the generated acoustic field 208 generated from the tips 204a,b.
[0096] In FIG. 17B, the control module 207 is set up in favor of one sonotrode 202a so that said sonotrode 202a receives a bigger amount of electrical energy than the other one receives. As a result, the emitted acoustic filed 208 corresponds more to the acoustic field contribution of the sonotrode 202a, that receives a higher amount of the electrical energy, than the acoustic field contribution from the other sonotrode that receives a lower amount of electrical energy. In this embodiment, it is possible, when the device is placed in a vessel, to position the emitted acoustic field for instance toward a side of the vessel, to provide a major contribution of the acoustic field on the side of the vessel, and a minor contribution on the other side of the vessel. This can improve the treatment of an eccentric lesion by increasing the efficiency of the treatment on the area of the vessel where the treatment is needed and to protect, by limiting the acoustic field, the area where the treatment is not necessary.
[0097] FIG. 18 is a chart representing the control module 17,107,207 used in the device according to the disclosed embodiments 10a,b, 100a,b, 200. The controller 17, 107, 207 controls the energy supply to each sonotrode so as to set up de emitted acoustic field 18, 108, 208. The controller is composed of a central unit equipped of a microcontroller or DSP or FPGA. This central unit controls through n outputs stage (n corresponding of the number of transducer), the frequency and the voltage to apply (i.e. the correct amount of energy) to each transducer in the goal to obtain the desired amplitude of displacement on each wire. A feedback on the amplitude value of displacement comes from each transducer and is interpreted by the central unit which can, by a control loop, control in real time the amount of energy to give to each transducer. A lookup table contains all the parameters necessary for the proper functioning of the device, depending on the case of n wires on one tip, or n wires and n tip, or the geometry of the tip as well as the safety parameters. The central unit is connected to a user interface that permits the user to control the device and to have feedback information on the status of the system.
[0098] FIGS. 19A through 19F shows some embodiments of the tip 14, 104, 204 that can be used in the device according to the present invention. The shape of the tip 14, 104,204 can be: Spherical (FIGS. 6 and 11); hemispherical (FIG. 19A); spherical with lobes fixed thereon (FIGS. 19B and 19E); ovoid with a cavity (FIG. 19C); cylindrical with a cavity in the body of the cylinder (FIG. 19D); or cylindrical (FIG. 19F).
[0099] Advantageously, the shape of the tip can be chosen depending on the shape of the emitted acoustic field, according to the type of area to treat and according to the choice of the control mode privileged for the procedure (PWM, Wobulation, phase shift).
REFERENCES OF THE FIGURES
[0100] 1 Device according to the prior art [0101] 2 Power generator [0102] 3 Piezoelectric transducer [0103] 4 Horn [0104] 5 Catheter [0105] 6 Transmission wire [0106] 7 Tip [0107] 8 Acoustic field [0108] 10a Device according to a first embodiment with two transmission wires on one tip [0109] 10b Device according to a second embodiment with two transmission wires on one tip, one wire is fixed [0110] 11 Power generator [0111] 12a,b Sonotrode [0112] 13a,b Transmission wire [0113] 14 Tip [0114] 15a,b Transducer [0115] 16a,b Horn [0116] 17 Control module [0117] 18 Emitted acoustic field [0118] 19 Blind hole [0119] 20 Traversing hole [0120] 21 Mechanically fixed anchor point [0121] 100a Device according to a third embodiment with three transmission wires on one tip [0122] 100b Device according to a fourth embodiment with three transmission wires on one tip, one wire is fixed [0123] 101 Power generator [0124] 102a,b,c Sonotrode [0125] 103a,b,c Transmission wire [0126] 104 Tip [0127] 105a,b,c Transducer [0128] 106a,b,c Horn [0129] 107 Control module [0130] 108 Emitted acoustic field [0131] 109 Blind hole [0132] 110 Traversing hole [0133] 111 Mechanically fixed anchor point [0134] 200 Device according to a fifth embodiment [0135] 201 Power generator [0136] 202a,b Sonotrode [0137] 203a,b Transmission wire [0138] 204a,b Tip [0139] 205a,b Transducer [0140] 206a,b Horn [0141] 207 Control module [0142] 208 Emitted acoustic field
