Methods, systems and devices for generating pressure waves in intravascular lithotripsy
Various embodiments of the systems, methods and devices are provided for breaking up calcified lesions in an anatomical conduit. More specifically, an electrical arc is generated between two spaced-apart electrodes disposed within a fluid-filled balloon, creating a subsonic pressure wave. In some embodiments, the electrodes comprise a plurality of points that allow the electrical arc to form at any one of the plurality of points to, among other things, extend the electrode life.
1 . A method for monitoring progress of an intravascular balloon lithotripsy procedure that directs energy toward a lesion comprising at least one calcified region and located within a blood vessel, the method comprising:
providing an elongate member, a fluid inflatable balloon surrounding a portion of the elongate member, and at least one pair of spaced-apart electrodes located along the elongate member and within an interior of the fluid inflatable balloon, the at least one pair of spaced-apart electrodes defining at least one spark gap;
providing a voltage pulse generator operatively connected with the at least one spaced-apart electrode pair;
providing a controller in operative communication with the voltage pulse generator and comprising a processor and a memory, the processor configured to execute programmed instructions;
initiating a plurality of voltage pulses with the voltage pulse generator;
positioning the fluid inflatable balloon proximate the lesion and inflating the fluid inflatable balloon with fluid to a predetermined pressure, wherein the fluid comprises a resistance and/or an impedance;
applying an initiated voltage pulse of the plurality of voltage pulses to each one of the at least one spaced-apart electrode pairs;
generating a plurality of electrical arcs between the electrodes of each one of the at least one pair of spaced-apart electrodes;
monitoring the resistance and/or impedance of the fluid within the fluid inflatable balloon and measuring a change in the resistance and/or impedance of the fluid before the generating of the plurality of electrical arcs; and
measuring the change in resistance and/or impedance of the fluid during the generating of the plurality of electrical arcs,
wherein the measured change in resistance and/or impedance of the fluid corresponds with an expansion of the fluid inflatable balloon.
2 . The method of claim 1 , further comprising monitoring the resistance and/or impedance in the fluid proximate at least one of the plurality of pairs of spaced-apart electrodes.
3 . The method of claim 1 , further comprising measuring a decrease in the resistance and/or impedance of the fluid during the expansion.
4 . The method of claim 3 , wherein a decrease in the resistance and/or impedance of the fluid corresponds with the expansion of the fluid inflatable balloon.
5 . The method of claim 4 , wherein the expansion of the fluid inflatable balloon corresponds with progress of the lithotripsy procedure in cracking one or more calcified regions of the lesion.
6 . The method of claim 5 , further comprising providing an alert for the progress of the lithotripsy procedure.
7 . The method of claim 6 , further comprising determining when the lithotripsy procedure is sufficiently complete based on the measured resistance and/or impedance of the fluid during the generating of the plurality of electrical arcs.
8 . The method of claim 7 , further comprising providing an alert that the lithotripsy procedure is sufficiently complete.
9 . The method of claim 7 , further comprising:
comparing the resistance and/or impedance of the fluid before generating the plurality of electrical arcs with the measured resistance and/or impedance of the fluid during the generating of the plurality of arcs;
monitoring the progress of the lithotripsy procedure based on the comparison;
determining when the lithotripsy procedure is sufficiently complete based on the comparison; and
providing an alert that the lithotripsy procedure is sufficiently complete.