Stone disintegrator

Claim 2

In an instrument for attacking calculi of a patient in a liquid medium surrounding the calculi, said instrument including a lithotrite having a free, discharge, end, said free, discharge, end being disposed, in operation, adjacent the calculi being attacked, the improvement comprising: means for detecting if said discharge end is adjacent to tissue of said patient; said means for detecting being disposed at said discharge end whereby said means for detecting is disposed, in operation, adjacent said calculi being attacked; and means for preventing operation of said instrument when said discharge end is adjacent said tissue.

Claim 3

The improvement of claim 1 wherein said means for detecting comprises an impedance level detector; means for connecting an input of said impedance level detector to the center and outer conductors respectively of said lithotrite; whereby, when said lithotrite is in said liquid medium, said impedance level detector detects the conductivity of the liquid medium.

Claim 4

The improvement of claim 2 wherein said means for detecting determines whether the measured conductivity falls within predetermined levels of conductivity; and means for actuating said instrument when the measured conductivity falls within the predetermined levels.

Claim 5

The improvement as defined in claim 3 wherein said means for detecting comprises microprocessor means.

Claim 6

The improvement as defined in claim 4 wherein said instrument includes a power input means and a transformer, the primary of said transformer being connected to said power input means; electronic switch means in circuit with said primary, said electronic switch means being normally biased in its off, or non-conductive, condition, said electronic switch including a control terminal; said means for determining comprising an output trigger terminal, said trigger terminal being connected to the control terminal of said electronic switch; whereby, when said measured conductivity falls within said predetermined levels, said means for determining provides a triggering pulse on said triggering terminal to turn said electronic switch on.

Claim 7

The improvement as defined in claim 5 wherein said electronic switch comprises a triac.

Claim 8

The improvement as defined in claim 6 and including manual override switch in parallel with said electronic switch to short-out said electronic switch when said manual override switch is closed.

Claim 9

The improvement as defined in claim 6 and including manual override means for maintaining said triac in a continuous conductive condition, comprising, manual means for controlling said microprocessor means to provide an artificial conductivity level which falls within said predetermined levels whereby said triac remains in a continuously conductive state regardless of the conductivity of the liquid medium.

Claim 10

In an instrument for attacking calculi of a patient in a liquid medium surrounding the calculi, said instrument including a lithotrite having a free, discharge, end, said free, discharge, end being disposed, in operation, adjacent the calculi being attacked, the improvement comprising: means for measuring the conductivity of the liquid medium said means for measuring being disposed in the discharge end of said instrument; and means for preventing operation of said instrument when said conductivity falls outside of predetermined limits; whereby, when said instrument is in operation, said means for measuring is adjacent said calculi being attacked.

Claim 11

In an instrument for attacking calculi of a patient in a liquid medium surrounding the calculi, said instrument including a lithotrite having a free, discharge, end, said free, discharge, end being disposed, in operation, adjacent the calculi being attacked, the improvement comprising: means for measuring the conductivity of the liquid medium said means for measuring being disposed in the discharge end of said instrument; and means for preventing operation of said instrument when said conductivity falls outside of predetermined limits; whereby, when said instrument is in operation, said means for measuring is adjacent said calculi being attacked.