Stone disintegrator

• US 3,902,499 A
• Filed: 01/02/1974
• Issued: 09/02/1975
• Est. Priority Date: 01/02/1974
• Status: Expired due to Term

• Current Assignee: William Richard Shene
• Original Assignee: William Richard Shene
• Inventors: Shene, William Richard
• Primary Examiner(s): Pace, Channing L.
• Application Number:
  US05/429,484
• Time in Patent Office: 608 Days
• Field of Search: 128/328,421
• US Class Current: 606/128
• CPC Class Codes: A61B 17/22022 using electric discharge
• CPC Class Codes: A61B 17/221 Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions surgical snare instruments A61B17/32056
• CPC Class Codes: A61B 2017/00973 pedal-operated
• CPC Class Codes: A61B 2017/320078 Tissue manipulating surface
• CPC Class Codes: G10K 15/06 using electric discharge

Abstract

This invention relates to an instrument for disintegrating calculi in the urinary tract by hydraulic impacts formed by electrical discharges in the liquid medium surrounding the calculi. Instruments employing this general principle are well known and they usually consist of a lithotrite having two electrodes, and a pulse forming network connected to the electrodes to provide electrical energy for forming discharge between the lithotrite electrodes. In the lines connecting the pulse forming network to the lithotrites, the prior art instruments include spark gaps. These gaps have the disadvantages of being temperature and humidity dependent and of providing a great deal of service and maintenance problems. In accordance with the invention, the spark gaps are replaced by solid state switch devices such as thyristors. The switching devices are controlled by a solid state pulse generator, and the repetition rate and intensity of the electrical discharges can be varied by varying the repetition rate and pulse duration of the pulse generator.

Claims

1. An instrument for attacking calculi in a liquid medium surrounding the calculi, comprising:

lithotrite means comprising a first electrode and a second electrode spaced from said first electrode;

means for providing electrical energy to said electrodes to cause a spark discharge between said first and second electrodes in said liquid medium, said means comprising capacitive storage means connected to a first output terminal and a second output terminal;

a first lead connecting said first output terminal to said first electrode and a second lead connecting said second output terminal to said second electrode;

a first solid state switch in said first lead between said first output terminal and said first electrode;

a second solid state switch in said second lead between said second output terminal and said second electrOde; and

pulse generator means connected to said first and second solid state switches for providing control signals to said first and second solid state switches, said pulse generator means having means for varying the pulse duration and the pulse repetition rate of said control signals.

2. An instrument as defined in claim 1 wherein said solid state switches comprise thyristors having gate electrodes and said pulse generator means is connected to the gate electrodes of said thyristors;

whereby the intensity and repetition rate of said spark discharge are variable.

3. An instrument for attacking calculi in the urinary tract by electro-hydraulic impacts in a liquid medium surrounding the calculi, comprising:

a pulse forming network having an input circuit for receiving input voltage to said pulse forming network;

said pulse forming network comprising capacitive storage means connected to two output leads;

solid state switch means in each of said output leads;

said instrument further comprising a lithotrite having a first electrode and a second electrode spaced from said first electrode;

means for connecting one of said output leads to said first electrode;

means for connecting the other output lead to said second electrode; and

pulse generator means connected to said solid state switch means for providing control signals to said solid state switch means, said pulse generator means having means for varying the pulse duration and pulse repetition rate of said control signals.

4. An instrument as defined in claim 3 wherein said solid state switches comprise thyristors having gate electrodes and said pulse generator means is connected to the gate electrodes of said thyristors;

whereby the intensity and repetition rate of said spark discharge are variable.

5. An instrument as defined in claim 3, wherein said first and second electrodes of said lithotrite are co-axially arranged;

said first electrode comprising an inner conductor in said co-axial arrangement; and

said second electrode comprising an outer conductor in said co-axial arrangement.

6. An instrument as defined in claim 5, wherein said lithotrite comprises flexible fingers extending therefrom.