Method for intracorporeal lithotripsy fragmentation and apparatus for its implementation

• US 20030176873A1
• Filed: 03/12/2002
• Published: 09/18/2003
• Est. Priority Date: 03/12/2002
• Status: Active Grant

• Current Assignee: Lithotech Medical Ltd. (Nordson Corporation)
• Original Assignee: Lithotech Medical Ltd. (Nordson Corporation)
• Inventors: Lerner, Marat, Chernenko, Vladimir, Khachin, Stepan, Khachin, Vladimir, Diamant, Valeri
• Granted Patent: US 7,087,061 B2
• Time in Patent Office: Days
• US Class Current: 606/127
• CPC Class Codes: A61B 17/22022 using electric discharge
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2018/0041 Removal of thrombosis
• CPC Class Codes: A61B 2018/00422 Angioplasty
• CPC Class Codes: A61B 2018/1213 creating an arc

Abstract

Electro-impulse intracorporeal lithotripsy comprises bringing electrodes of a probe in immediate electrical contact with the calculus and supplying to the electrodes of very short high voltage impulses capable to ignite electrical spark discharge and establish a discharge channel within the bulk of the calculus. The channel goes through the calculus and creates tensile stresses, destroying the calculus.

Claims

1. A method for fragmenting of various calculi in a living body by intracorporeal lithotripsy treatment, during which a probe is brought to the calculus to be fragmented, said probe is provided with electrodes, connected to a means for generating of high voltage impulses, said impulses are supplied to the electrodes for igniting spark discharge between them and release of energy, causing fragmenting of the calculus, wherein the method comprises bringing of at least one of the electrodes in electrical contact immediate with the calculus so as to establish a discharge channel capable to create shock waves and stresses, which excess the strength of the calculus material.

2. The method of claim 1, in which said high voltage impulses are defined by the following parameters:

impulse rise time t_f less than 50 nanoseconds, duration of impulse itself t_i not more than 5000 nanoseconds, impulse energy W₀=0.1-1.0 joule, impulse amplitude U=5-20 kV

3. The method as defined by claim 2, in which said impulses are supplied as single impulses.

4. The method of claim 2, in which said impulses are supplied as repeating impulses with frequency of up to several tens of Hz.

5. The method of claim 2, in which said impulses are defined by the following parameters:

impulse rise time t_f less than 40 nanoseconds, duration of impulse itself t_i not more than 3000 nanoseconds.

6. The method of claim 5, in which the amplitude of said impulses, is below the value of single pulse breakdown threshold of the calculus.

7. The method of claim 1, comprising sensing the onset of the electrical breakdown, associated with fragmenting of the calculus.

8. The method of claim 7, comprising termination of the generation of the high voltage impulses as soon as the onset of the electrical breakdown is sensed.

9. The method of claim 8, comprising presetting certain amount of high voltage impulses to be supplied to the electrodes, counting the amount of impulses actually generated by the generator and termination the generation as soon as either the preset amount is achieved or the electrical breakdown is sensed.

10. The method of claim 1, comprising grasping the calculus before supplying the impulses and its containment during supplying the impulses.

11. An apparatus for fragmenting of calculi within a living body during intracorporeal lithotripsy treatment, said apparatus comprising:

a pulse generating means for generating high voltage impulses required for igniting electrical breakdown and producing energy sufficient for fragmenting the calculus,

a probe for insertion within the body and transferring the energy to the calculus, said probe comprises a sheath with electrodes, which reside within the sheath, said electrodes are provided with respective distal and proximal ends, the proximal ends of said electrodes are electrically connected to the pulse generating means and the distal end of at least one of the electrodes is adapted to be in electrical contact immediate with the calculus,

a probe manipulating means, for manipulating the sheath within the body and bringing at least one of the electrodes in electrical contact with the calculus.

12. The apparatus of claim 11, in which said electrodes comprise a first electrode, which extends along the longitudinal axis of the sheath and a second electrode, which is concentric and coaxial with the first electrode, said electrodes are electrically insulated, except of their forwardmost ends, which are intended to be in electrical contact with the calculus.

13. The apparatus of claim 11, in which the electrodes reside within the sheath with possibility for their linear displacement along the sheath from a retracted position to a protracted position and the distal ends of the electrodes are adapted to be in electrical contact immediate with the calculus when at least one of the electrodes is brought in the protracted position,

14. The apparatus of claim 13, in which said electrodes comprise a first electrode, which extends along the longitudinal axis of the sheath and a second electrode, which is concentric and coaxial with the first electrode, wherein the distal end of the second electrode is connected to a spreadable contacts, adapted to be opened and to grasp the calculus when the second electrode is in the protracted position.

15. The apparatus of claim 14, in which said spreadable contacts are made of elastic, electrically conductive material, said contacts are electrically insulated, except of their forwardmost ends, which are intended to be in electrical contact with the calculus.

16. The apparatus of claim 14, in which the contacts are made of TiNi.

17. The apparatus of claim 15, in which the contacts have rectilinear configuration and their most forward ends are bent.

18. The apparatus of claim 15, in which the contacts are provided with arched configuration.

19. The apparatus of claim 15, in which the contacts comprise a retrieval basket.

20. The apparatus of claim 12, in which the electrodes comprise two conducting wires extending along a cable.

21. The apparatus of claim 12, in which said pulse generating means comprises a charging means, a first capacitor means, a commutating means, a pulse generating circuit and a control circuit.