LITHOTRIPSY DEVICE, LITHOTRIPSY SYSTEM AND METHOD FOR OPERATING A LITHOTRIPSY DEVICE

Abstract

The disclosure relates to a lithotripsy device comprising an elongate probe, which can be inserted into a body interior of a human or animal body, and a drive arrangement for deflecting the probe, which is arranged at a proximal portion of the probe, the drive arrangement comprising an ultrasonic converter unit for exciting ultrasonic vibrations in the direction of a longitudinal extension of the probe, and the drive arrangement having a deflection device for exerting a time-varying force onto the probe in a direction transversely to the longitudinal extension of the probe. The disclosure also relates to a lithotripsy system and to a method for operating a lithotripsy device.

Claims

1. A lithotripsy device, comprising: an elongate probe which is insertable into the interior of a human or animal body; and a drive arrangement arranged on a proximal portion of the probe and serving to deflect the probe; wherein the drive arrangement comprises an ultrasonic converter unit for exciting ultrasonic vibrations in the direction of a longitudinal extent of the probe; and the drive arrangement comprises a deflection device for exerting a time-variable force on the probe in a direction transverse to the longitudinal extent of the probe; and wherein the deflection device is designed to exert the time-variable force by an impact exerted on a lateral surface of the probe by means of at least one impact element.

2. The lithotripsy device as set forth in claim 1, wherein a frequency and/or an intensity of the time-variable force is adjustable.

3. The lithotripsy device as set forth in claim 1, wherein the at least one impact element is designed as a ram or hammer which is movable by means of a drive device in order to exert the impact on the probe.

4. The lithotripsy device as set forth in claim 1, wherein the at least one impact element is designed as a frame which is movable by means of a drive device, or as a slotted disk which is movable by means of a drive device, in order to exert the impact on the probe.

5. The lithotripsy device as set forth in claim 3, wherein the drive device is designed as a linear drive or in the manner of a hammer interrupter.

6. The lithotripsy device as set forth in claim 3, wherein the drive device includes a cam disk acting against a spring force, or a slider crank which can be driven by an electric motor, a piezo motor, a pneumatic motor or a turbine, or comprises an electric motor which can be controlled to perform a reciprocating movement.

7. The lithotripsy device as set forth in claim 1, wherein the at least one impact element is designed as a mass body which is movable by means of a drive device on a circular path in order to exert the impact on the probe.

8. The lithotripsy device as set forth in claim 1, wherein the deflection device for exerting the time-variable force on the probe is designed in the form of an unbalance which can be driven by means of a drive device or in the form of an eccentric which can be driven by means of a drive device.

9. The lithotripsy device as set forth in claim 7, wherein the drive device includes an electric motor, a piezo motor, a pneumatic motor, a turbine, or an electric motor which can be controlled to perform a reciprocating movement.

10. The lithotripsy device as set forth in claim 3, wherein a motor of the drive device is connected to the deflection device via a flexible shaft.

11. The lithotripsy device as set forth in claim 1, wherein the deflection device is arranged in such a way that the time-variable force acts on the probe, in the direction transverse to the longitudinal extent of the probe, distally with respect to the ultrasonic converter unit.

12. The lithotripsy device as set forth in claim 1, wherein the probe extends in the proximal direction beyond the ultrasonic converter unit, and in that the deflection device is arranged in such a way that the time-variable force acts on the probe, in the direction transverse to the longitudinal extent of the probe, proximally with respect to the ultrasonic converter unit.

13. The lithotripsy device as set forth in claim 1, wherein the deflection device is arranged to exert a force on the ultrasonic converter unit in order to exert the time-variable force on the probe in the direction transverse to the longitudinal extent of the probe.

14. The lithotripsy device as set forth in claim 1, wherein the ultrasonic converter unit is mounted movably in a surrounding housing.

15. The lithotripsy device as set forth in claim 14, wherein the ultrasonic converter unit is mounted resiliently in the surrounding housing and/or pivotably about a pivot axis transverse to the longitudinal extent of the probe.

16. The lithotripsy device as set forth in claim 1, wherein the drive arrangement is designed to exert a further time-variable force on the probe in a further direction transverse to the longitudinal extent of the probe.

17. A lithotripsy system comprising: a lithotripsy device according to claim 1; and an endoscope having a channel for inserting the probe into the interior of the human or animal body, wherein the channel is dimensioned so as to allow a lateral deflection of the probe, effected by the time-variable force in the direction transverse to the longitudinal extent of the probe, to be transmitted to a distal end of the probe.

18. A method for operating a lithotripsy device comprising an elongate probe, wherein the probe, in a proximal portion, is excited to perform ultrasonic vibrations in the direction of a longitudinal extent of the probe, which ultrasonic vibrations are transmitted through the probe to a distal end of the probe, and, in the proximal portion, a time-variable force is exerted on the probe in a direction transverse to the longitudinal extent of the probe, and a lateral deflection of the probe brought about thereby is transmitted through the probe to the distal end of the probe; and wherein the time-variable force is exerted by an impact exerted on a lateral surface of the probe.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0051] Further aspects of the disclosure will become clear from the following description of preferred exemplary embodiments and by reference to the appended schematic drawings, in which:

[0052] FIG. 1 shows a diagrammatic view of the mode of operation of a device according to the disclosure;

[0053] FIGS. 2a and 2b show a first exemplary embodiment of a device according to the disclosure;

[0054] FIG. 3 shows a second exemplary embodiment of a device according to the disclosure;

[0055] FIGS. 4a to 4c show a third exemplary embodiment of a device according to the disclosure;

[0056] FIGS. 5a and 5b show a fourth exemplary embodiment of a device according to the disclosure;

[0057] FIGS. 6a and 6b show a fifth exemplary embodiment of a device according to the disclosure;

[0058] FIGS. 7a and 7b show a sixth exemplary embodiment of a device according to the disclosure;

[0059] FIG. 8 shows a seventh exemplary embodiment of a device according to the disclosure;

[0060] FIG. 9 shows an eighth exemplary embodiment of a device according to the disclosure;

[0061] FIGS. 10a and 10b show a ninth exemplary embodiment of a device according to the disclosure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0062] As is shown in FIG. 1 in the form of a simplified schematic diagram, a lithotripsy device comprises an elongate probe 1, which is also referred to as a sonotrode, and an ultrasonic converter unit 2, which is arranged on a proximal portion 3 of the probe 1. The probe 1 is designed for insertion into the interior of a human or animal body, such that a distal end 4 of the probe 1, also referred to as the probe tip, can be introduced through a natural or artificial body opening and advanced to a stone located inside the body. For this purpose, the probe 1 can be inserted into a corresponding channel of an endoscope passed through the body opening, for example through a nephroscope (not shown) to a kidney stone located in the renal pelvis. The proximal portion 3 of the probe 1 with the ultrasonic converter unit 2 remains outside the body and possibly also outside the endoscope. The probe 1 is preferably rigid, but may also be flexible or semi-rigid, and is typically made of stainless steel. The distal end 4 of the probe 1 can also have a movable crown.

[0063] The ultrasonic converter unit 2 comprises an ultrasonic transducer 5 which is coupled to a horn 6 in order to transmit ultrasonic vibrations. As a rule, the horn 6 is permanently connected to the ultrasonic transducer 5. The probe 1 is attached to a distal end of the horn 6. The probe 1 can, for example, be screwed into a through-bore 7 of the horn 6 so that a collar 8 of the probe 1 bears firmly on the distal end of the horn 6. The probe 1 can extend in the proximal direction through the ultrasonic transducer 5 or end in the region of the horn 6, for example. The horn 6 serves to amplify the ultrasonic vibrations generated by the ultrasonic transducer 5 and to couple the ultrasonic vibrations into the probe 1.

[0064] The coupled-in ultrasonic vibrations are transmitted as ultrasonic waves through the probe 1 to its distal end 4 and cause the latter to vibrate accordingly. As a rule, the ultrasonic transducer 5 is activated to generate standing waves in the probe 1, so that a vibration amplitude at the distal end 4 of the probe 1 is at a maximum. By placing the distal end 4 onto a stone in the body, these can lead to fragments breaking off or to the stone being made smaller. In this way, the stone can be gradually ablated or crushed.

[0065] It is indicated in FIG. 1 that the probe 1 can be designed as a hollow probe which has a continuous flushing channel 9. An attachment can be provided at a proximal end 10 of the ultrasonic transducer 5 or of the probe 1 for the purpose of attaching a flushing or suction device in order to remove the fragments of the stone that have formed. Alternatively, a flushing or suction connection can be provided on the side of the probe 1, distally with respect to the horn 6. By applying a negative pressure to the flushing channel 9, the stone can be sucked onto the distal end 4 of the probe 1, and shifting of the stone during treatment can thus be prevented.

[0066] As is shown symbolically in FIG. 1, the ultrasonic vibrations or ultrasonic waves generated by the ultrasonic transducer 5 and coupled into the probe 1 by the horn 6 are of a longitudinal nature, i.e. the corresponding deflection of the probe 1 takes place in the direction of the longitudinal extent of the probe. This longitudinal direction is indicated by the arrow 11. In addition, the generation of lateral ultrasonic waves by the ultrasonic converter unit 2 can also be provided.

[0067] According to the present disclosure, a time-variable transverse force F.sub.q acts on the probe 1 in a direction transverse to the longitudinal direction of the probe 1 and causes a lateral deflection of the probe 1. A deflection device is provided for this purpose and is arranged to exert the variable transverse force F.sub.q on the probe. For example, a flexural vibration of the probe 1 can be excited by a temporary, temporally recurring lateral force and is transmitted from the probe 1 to the distal end 4 of the latter. The distal end 4 of the probe 1 thus performs, in addition to the longitudinal ultrasonic vibrations, a lateral movement which is generally of low frequency. Such a lateral movement of the distal end 4 allows a considerable improvement in the ablation and/or fragmentation effect of the probe 1.

[0068] As is indicated in FIG. 1, the force F.sub.q can act on the probe 1 distally with respect to the ultrasonic converter unit 2, but still in the proximal portion 3 of the probe 1, which remains outside the body or the endoscope; alternatively, the force F.sub.q acting in the transverse direction can be exerted on the probe 1 within or proximally with respect to the ultrasonic converter unit 2 or indirectly via the latter. To exert the transverse force F.sub.q on the probe 1, a deflection device is provided which can be designed and arranged, for example, as in the exemplary embodiments explained below.

[0069] In the first embodiment of the device according to the disclosure, shown in a side view in FIG. 2a, the deflection device comprises a linear drive 12 which, for example, can be a pneumatic cylinder, a linearly operating piezo motor or an electromagnet with a displaceable iron core, which drive an impact element designed as a frame 13. As is shown in FIG. 2b in an axial view, the probe 1 runs through the interior of the frame 13. As is indicated by the double arrow 14, the frame 13 is guided in a direction transverse to the longitudinal extent of the probe 1 and is driven by the linear drive 12 to perform a reciprocating motion. The linear drive 12 acts on the frame 13 via a piston rod 15 or via a linkage, possibly with a certain amount of play.

[0070] The end points of the reciprocating movement are determined such that the inner sides 16, 17 of the frame 13 alternately impact mutually opposite impact regions 18, 19 of the lateral surface of the probe 1; alternatively, the probe 1 can also be impacted on only one side. The frame 13 has a thickness in the longitudinal direction of the probe 1 such that the impact regions 18, 19, in which the frame comes into contact with the surface of the probe during impact, have a sufficient longitudinal extent to minimize wear on the surface of the probe 1 (see FIG. 2a). The deflection device with the linear drive 12 can comprise a holder, with which it is releasably attached (not shown) to the ultrasonic converter unit 2.

[0071] According to the embodiment shown in a side view in FIG. 3, a deflection device with a drive device is provided for the lateral deflection of the probe 1 and works in the manner of a hammer interrupter. In this case, a hammer 21 is arranged on a leaf spring 20 and is driven by an electromagnet 22 with an armature and with an interrupter contact coupled thereto to perform a reciprocating movement in the transverse direction, which is indicated by the double arrow 23 in FIG. 3, and strikes the lateral surface of the probe 1. The leaf spring 20 can be attached to the ultrasonic converter unit 2 via a holding bracket 24.

[0072] FIG. 3 shows an example in which a hose attachment nozzle 25 is provided on the proximal side of the ultrasonic converter unit 2, for the purpose attaching a flushing and/or suction device, and is connected to a continuous flushing channel 9 of the probe 1 (see FIG. 1). The ultrasonic transducer 5 also has a supply connection 26 for electrical connection to a control device (not shown). The ultrasonic converter unit 2 of the other exemplary embodiments can be constructed in a corresponding manner.

[0073] FIG. 4a shows a third exemplary embodiment of a device according to the disclosure in a lateral and partially sectioned view. As in the first exemplary embodiment, the probe 1 is subjected to impacts acting on one or both sides by means of a frame 27 that is displaceable in the transverse direction, for which purpose the probe 1 runs through the frame 27 and a displacement path of the frame 27 is dimensioned in such a way that at least one of the inner sides 16, 17 of the frame 27 strikes against a corresponding impact region of the lateral surface of the probe 1 during the displacement. In the third exemplary embodiment, the deflection device further comprises a cam disk 28, which acts on a roller 29 mounted rotatably near an upper edge of the frame 27.

[0074] As is shown in an axial view in FIG. 4b, the frame 27 is mounted slidably in a guide unit 30. Here, the frame 27 is pretensioned by a spring 31 in the direction of the cam disk 28 (see FIG. 4a). The cam disk 28, which is shown in FIG. 4c in a view seen obliquely from the distal direction, has a control surface 32 over which the roller 29 rolls during rotation of the cam disk 28. The control surface 32 occupies an angular range of approximately 90 with respect to an axis of rotation of the cam disk 28; the roller 29 is not in contact with the cam disk 28 in a remaining angular range. The cam disk 28 is fastened to a motor shaft 33 of an electric motor 34, for example with a clamping screw, and can be set in rotation thereby.

[0075] When the cam disk 28 rotates clockwise, seen from the proximal direction, the roller 29 rolls along the control surface 32 in the direction of its tip 35, such that the frame 27 is displaced downward against the force of the spring 31. An end point of this movement can be determined such that an upper inner side 17 of the frame 27 strikes an upper surface of the probe 1. When the roller 29 resting on the control surface 32 exceeds the tip 35 thereof, the frame is pushed upward by the spring 31, with the lower inner side 16 of the frame striking a lower surface of the probe 1. By driving of the cam disk 28 by means of the electric motor 34, the frame 27 can be set in a reciprocating motion, with impacts being exerted on one or both sides of the probe 1 in the transverse direction, which impacts lead to a lateral deflection of the probe. The mass of the frame can be 16 g, for example, and the speed with which the lower inner side 16 of the frame 27 strikes the lower surface of the probe 1, can be for example 2.4 m/s or more, in order to achieve a sufficient impact effect for the lateral deflection of the probe.

[0076] FIG. 4a shows that the electric motor 34 and the ultrasonic converter unit 2 are arranged parallel to each other and are each firmly mounted in a surrounding housing 36. The surrounding housing 36 can be designed as a handpiece. The surrounding housing 36 comprises a closure plate 37 on the distal side, on which the guide unit 30 and a cover 38 of the cam disk 28 are held, and a closure plate 39 on the proximal side, through which protrude the hose attachment nozzle 25 and a connection socket 40 for connecting the electric motor 34 to a control device. The closure plates 37, 39 are screwed onto a body 41 of the surrounding housing 36. The relative position of the cam disk 28 and of the frame 29 in relation to the ultrasonic converter unit 2, relative to the longitudinal direction of the probe 1, defines an impact region of the probe 1 in which the force acting in the transverse direction acts on the probe 1. In the arrangement shown in FIG. 4a, the transverse force is exerted on the probe 1 distally with respect to the ultrasonic converter unit 2, at a distance of about 50 mm from the collar of the probe 1 or from the distal end of the horn 6.

[0077] FIGS. 5a and 5b show a fourth embodiment of the device according to the disclosure in a lateral view and an axial view. As in the third exemplary embodiment, an electric motor 34 is provided here, which is mounted parallel to the ultrasonic converter unit 2 in a symbolically indicated surrounding housing 36. The electric motor 34 drives a slider crank mechanism 42 which comprises a drive disk 43, fastened to the motor shaft 33, and a slotted disk 44 which is mounted pivotably on the surrounding housing 36 and is connected to the drive disk 43 via a crank rod 45. As is indicated in FIG. 5b, a rotation (arrow 46) of the drive disk 43 is thereby converted into a reciprocating pivoting movement (double arrows 47, 48) of the slotted disk 44, with the axis 49 of the pivoting movement being directed parallel to the longitudinal extent of the probe 1. The starting point and end point of the pivoting movement are selected in such a way that the probe 1, which runs through the slot 50 of the slotted disk 44 (the slot being radial with respect to the axis 49), is subjected on one or both sides to a force from the walls of the slot 50, in particular an impact force. This can also cause a deflection of the probe 1 in the transverse direction.

[0078] In the fifth embodiment shown in FIGS. 6a and 6b in a side view and an axial view, a coupling via a slider crank mechanism is replaced by a slotted disc 51 mounted on the motor shaft 33 of the electric motor 34. This is arranged in such a way that the probe 1 lies within the radial slot 52 of the slotted disk 51. The electric motor 34 is controlled in such a way, for example with a square-wave voltage, that the motor shaft 33 with the slotted disk 51 held on it executes a reciprocating movement (double arrow 53) in which the probe 1 is touched by one inner side or alternately by both inner sides 54, 55 of the walls of the slot 52. With this embodiment too, which can otherwise be configured like the fourth embodiment, the probe can be subjected to a force acting in the transverse direction and, given a corresponding design, in particular an impact effect.

[0079] In the embodiment shown in FIGS. 7a and 7b in a side view and an axial view, an electric motor 34 with a motor shaft 33, which runs substantially parallel to the longitudinal direction of the probe 1, is arranged next to the ultrasonic converter unit 2 and can be connected to the latter in a manner similar to that explained in FIG. 4a. According to FIG. 7a, the deflection device comprises a drive disk 56 which is mounted on the motor shaft 33 of the electric motor 34 and near the circumference of which a plurality of impact bodies are arranged. In the example shown, these are six ball bearings 57, each of which is held with play on a bolt 58 which is directed parallel to the axis. Upon rotation of the drive disk 56, the outer rings of the ball bearings 57 strike the side of the probe 1 and thereby subject the probe 1 to a force directed transversely to the longitudinal extent of the probe 1, which is thereby excited to transverse vibration.

[0080] According to FIG. 8, in a further embodiment that is otherwise designed as described above, impact masses 59 are each held on a rotatable drive disk 61 by means of a thread 60; instead of the thread 60, another flexible holding means, such as a chain, can also be provided. When the drive disk 61 is set in rotation by means of the electric motor, the impact masses 59 follow a circular path, as is indicated symbolically by the arrow 62. The path is routed in such a way that the impact masses 59 strike the surface of the probe 1 in the process.

[0081] In the exemplary embodiments described above, provision is made in each case that the time-variable force transverse to the longitudinal direction of the probe 1 acts on the probe 1 distally with respect to the ultrasonic converter unit 2. FIG. 9 shows an exemplary embodiment of the disclosure in a partially sectioned side view in which the time-variable force acting in the transverse direction acts on the probe 1 proximally with respect to the ultrasonic converter unit 2.

[0082] As is shown in FIG. 9, the ultrasonic converter unit 2 comprises an ultrasonic transducer 5 and a horn 6. The ultrasonic transducer 5 comprises a plurality of piezoelectric elements 63, stacked on one another in the longitudinal direction, for generating ultrasonic vibrations. The horn 6 and the ultrasonic transducer 5 have a through-bore 7 which is continuous in the longitudinal direction and through which the probe 1 is guided beyond the proximal end of the ultrasonic transducer 5.

[0083] A deflection device 64 is arranged proximally with respect to the ultrasonic transducer 5 and is accommodated in a housing 65 into which the probe 1 extends through a bore aligned with the through-bore 7 of the ultrasonic converter unit 2. In the embodiment shown in FIG. 9, the probe 1 has an axially continuous flushing channel 9 and is routed as far as a proximal side of the housing 65, where a hose connection nozzle 25 is arranged which communicates with the flushing channel 9.

[0084] An electric motor 66 is accommodated in an interior space of the housing 65, and a force acting in the transverse direction is exerted on the probe 1 by means of an eccentric disk 67, which can be set in reciprocating or continuous rotation by the electric motor 66 and thereby strikes against the probe 1. In principle, the deflection device 64 can instead be designed with a slotted disk or in accordance with another of the exemplary embodiments described above. The through-bore 7 is designed with sufficient clearance so that the deflections of the probe 1 generated in this way in the transverse direction can be transmitted through the ultrasonic converter unit 2 in the distal direction.

[0085] In this way, on the one hand, an impact can be exerted on the probe 1 in order to introduce a shock-like force, and, on the other hand, the rotating eccentric disk can also act as an unbalance or centrifugal mass which, via the electric motor 66 mounted in the housing 65, sets the unit formed by the deflection device 64 and the ultrasonic converter unit 2, and thus the proximal portion of the probe 1, in additional vibrations in the transverse direction, which generally represent lower frequency components compared to the impact excitation. These can likewise be transmitted to the distal end 4 of the probe 1 and deflect the latter in the transverse direction. The deflection device 64 and the ultrasonic converter unit 2 can be accommodated in a surrounding housing (not shown), which can be designed as a handpiece, and they can be mounted therein resiliently, for example.

[0086] According to the ninth exemplary embodiment shown in FIGS. 10a and 10b in two side views rotated by 90 relative to each other, the ultrasonic converter unit 2 is moved, by a drive device 68 which acts between a surrounding housing 69 and the ultrasonic converter unit 2, in a reciprocating pivoting motion about an axis 70 which is transverse to the longitudinal axis of the probe 1 and which crosses through the ultrasonic converter unit 2 in a central portion. For this purpose, the drive device 68 can comprise, for example, a linear drive, such as a magnetic coil with a movable iron core, a piezo motor or an electric motor with a crank drive, as a result of which a time-variable transverse force is continuously exerted on the ultrasonic converter unit 2, in particular an alternating upward and downward force. Due to the pivoting movement of the ultrasonic converter unit 2 that is generated in this way, the probe 1 is deflected in the transverse direction in its proximal portion, as a result of which a lateral deflection of the distal end of the probe 1 can also be brought about.

[0087] In the above description, the terms up and down are to be understood only with reference to the representation in the figures; depending on the orientation of the device, a feature described in this way can also be oriented differently. The term lateral is used with reference to the longitudinal extent of the probe 1 and in particular denotes a lateral surface of a cylindrically designed probe 1.

[0088] For the sake of clarity, not all the reference signs are shown in all of the figures. Reference signs not explained in relation to a figure have the same meaning as in the other figures.