Device for fragmenting substances
A device for fragmenting substances comprises a probe having an elongate probe shaft on the distal end of which a probe head is arranged, said probe head comprising an electro-hydraulic converter with which electrical energy, delivered via the probe shaft from the proximal direction, is converted in shock-like manner into mechanical kinetic energy, said converter comprising a housing which accommodates a liquid chamber and a shock-transmitting element which is designed as a piston and which can be moved in the longitudinal direction of the housing from a proximal end position to a distal end position, the distal end position being defined by an abutment on the housing, which abutment is struck by a counter-abutment arranged on the shock-transmitting element. The abutment and the counter-abutment are designed in such a way that, during its movement from the proximal end position to the distal end position, the counter-abutment comes directly into contact with the abutment, and the shock-transmitting element is moved back again to the proximal end position essentially by the impact on the abutment.
1. A device for fragmenting substances, comprising:
a probe having an elongate probe shaft having a distal end and a proximal end, a probe head arranged at said distal end,
said probe head comprising an electro-hydraulic converter with which electrical energy, delivered via said probe shaft, is converted in shock-like manner into mechanical kinetic energy,
said electro-hydraulic converter having a housing having a longitudinal direction, which accommodates a liquid chamber and a shock-transmitting element designed as a piston and moveable in said longitudinal direction of said housing from a proximal end position into a distal end position,
said probe shaft having at least one delivery line for a liquid extending through the probe shaft and into said liquid chamber of said electro-hydraulic converter,
said distal end position being defined by an abutment on said housing, toward which abutment a counter-abutment runs, which is arranged on said shock-transmitting element,
said abutment and said counter-abutment being designed in such a way that, during a movement of said shock-transmitting element from said proximal end position to said distal end position, said counter-abutment comes directly into contact with said abutment, and said shock-transmitting element is moved back again to said proximal end position essentially by the impact of said counter-abutment on said abutment.
2. The device of claim 1 , wherein said shock-transmitting element is held in said proximal end position by means of a holding mechanism, which withdraws essentially no kinetic energy from said shock-transmitting element during said movement from said proximal end position to said distal end position.
3. The device of claim 2 , wherein said holding mechanism comprises a spring which is designed in such a way that a maximum possible spring travel of said spring is greater than a path of said shock-transmitting element between said proximal end position and said distal end position.
4. The device of claim 3 , wherein said spring is a compression spring whose length is greater than said path of said shock-transmitting element between said proximal end position and said distal end position.
5. The device of claim 4 , wherein said spring is arranged around a distal portion of said shock-transmitting element and having a distal end and a proximal end, said distal end bearing on said housing and said proximal end bearing on a shoulder of said shock-transmitting element, without lying in a running path of said counter-abutment.
6. The device of claim 2 , wherein said holding mechanism holds said shock-transmitting element in said proximal end position by means of magnetic force.
7. The device of claim 1 , wherein said counter-abutment is designed as a lateral projection which engages in a slide track in a wall of said housing, a distal end of said wall forming said abutment on said housing.
8. The device of claim 7 , wherein said slide track is delimited at a proximal end in order to define said proximal end position of said shock-transmitting element.
9. The device of claim 7 , wherein said lateral projection is formed by a pin which extends transversely through said shock-transmitting element and which at opposite ends engages in respective slide tracks in said wall of said housing.
10. The device of claim 1 , wherein a stroke of said shock-transmitting element between said proximal end position and said distal end position lies in a range from approximately 0.2 to approximately 2 mm.
11. The device of claim 1 , wherein a speed of said shock-transmitting element is at least 2 m/s.
12. The device of claim 1 , wherein a speed of said shock-transmitting element is at least 15 m/s.
13. The device of claim 1 , wherein a repetition frequency of said movement of said shock-transmitting element from said proximal end position to said distal end position is at least 2 Hz.
14. The device of claim 1 , wherein a repetition frequency of said movement of said shock-transmitting element from said proximal end position to said distal end position is at least 15 Hz.
15. The device of claim 1 , wherein said at least one delivery line is formed by at least one opening in a wall of said housing of said converter.
16. The device of claim 15 , wherein said at least one opening is arranged distally from a portion of said shock-transmitting element which portion permits passage of liquid into said liquid chamber but prevents penetration of voltage sparks.
17. The device of claim 1 , wherein said at least one delivery line is formed by at least one through-opening in said shock-transmitting element.
18. The device of claim 1 , wherein said probe shaft is flexible.
19. The device of claim 1 , wherein said probe head has, in its proximal area, a stiffening part.
20. The device of claim 19 , wherein said probe head has said stiffening part along an entire length of said probe head.
21. The device of claim 1 , wherein said probe head has a diameter of less than approximately 5 mm.
22. The device of claim 1 , wherein said probe is integrated in a catheter.
23. The device of claim 22 , wherein said catheter additionally has at least one lumen for at least one of a delivery and a removal of irrigation liquid.
24. The device of claim 22 , wherein said catheter additionally has a lumen for passage of a miniaturized endoscope.
25. The device of claim 1 , wherein an acoustic sensor is present which detects an acoustic signal of the ignition of said electro-hydraulic converter and of said impact of said shock-transmitting element on said substance.