Laser pulse shaping to enhance conversion efficiency and protect fiber optic delivery system for disruption of vascular calcium
A catheter system includes a power source, a controller, and a light guide. The power source generates a plurality of energy pulses. The controller controls the power source so that the plurality of energy pulses cooperate to produce a composite energy pulse having a composite pulse shape. The light guide receives the composite energy pulse. The light guide emits light energy in a direction away from the light guide to generate a plasma pulse away from the light guide. The power source can be a laser and the light guide can be an optical fiber. Each of the energy pulses has a pulse width, and the energy pulses are added to one another so that the composite energy pulse has a pulse width that is longer than the pulse width of any one of the energy pulses. At least two of the energy pulses can have the same wavelength as or a different wavelength from one another.
1 . A catheter system for treating a treatment site within or adjacent to a vessel wall or heart valve, the catheter system comprising:
a power source that generates a plurality of energy pulses;
a controller that controls the power source so that the plurality of energy pulses cooperate to produce a composite energy pulse having a composite pulse shape;
a light guide that receives the composite energy pulse, the light guide emitting light energy in a direction away from the light guide to generate a plasma pulse away from the light guide; and
an inflatable balloon that encircles a distal end of the light guide, the composite energy pulse generating a plurality of plasma pulses away from the distal end of the light guide,
wherein the catheter system is configured to generate a pre-bubble at the distal end of the light guide so that the plasma pulse is generated away from the light guide.
2 . The catheter system of claim 1 wherein the power source is a laser.
3 . The catheter system of claim 1 wherein the light guide is an optical fiber.
4 . The catheter system of claim 1 wherein each of the plurality of energy pulses are sub-millisecond pulses.
5 . The catheter system of claim 1 wherein the composite energy pulse is configured to generate the pre-bubble at the distal end of the light guide.
6 . The catheter system of claim 1 wherein the pre-bubble is generated by electrolysis.
7 . The catheter system of claim 1 wherein the pre-bubble is generated by using a resistive heater.
8 . The catheter system of claim 1 further comprising a nano surface that is positioned near the distal end of the light guide.
9 . The catheter system of claim 1 further comprising a nano surface that is positioned on the distal end of the light guide.
10 . The catheter system of claim 9 wherein the nano surface is textured.
11 . The catheter system of claim 1 further comprising a hydrophobic material that is positioned on the distal end of the light guide.
12 . The catheter system of claim 1 further comprising a hydrophobic material that is positioned near the distal end of the light guide.
13 . The catheter system of claim 1 wherein each of the energy pulses has a pulse width, and the energy pulses are added to one another so that the composite energy pulse has a pulse width that is longer than the pulse width of any one of the energy pulses.
14 . The catheter system of claim 1 wherein the composite energy pulse has a pulse amplitude that increases over time.
15 . The catheter system of claim 1 wherein the composite energy pulse has a pulse amplitude that decreases over time.
16 . The catheter system of claim 1 wherein the plurality of plasma pulses are generated at different times from one another.
17 . The catheter system of claim 1 wherein the controller controls a timing of the composite energy pulse relative to a start of the generation of the pre-bubble.
18 . The catheter system of claim 17 wherein the composite energy pulse is generated greater than approximately 1 ns and less than approximately 100 ms after the start of the generation of the pre-bubble.
19 . A catheter system for treating a treatment site within or adjacent to a vessel wall or heart valve, the catheter system comprising:
a power source that generates a plurality of energy pulses, the power source including a laser;
a controller that controls the power source so that the plurality of energy pulses overlap and combine to produce a composite energy pulse having a composite pulse shape;
a light guide that receives the composite energy pulse, the light guide emitting light energy in a direction away from the light guide to generate a plasma pulse away from the light guide, the light guide including an optical fiber; and
an inflatable balloon that encircles a distal end of the light guide,
wherein the catheter system is configured to generate a pre-bubble at the distal end of the light guide so that the plasma pulse is generated away from the light guide.
20 . A catheter system for treating a treatment site within or adjacent to a vessel wall or heart valve, the catheter system comprising:
a power source that generates a plurality of energy pulses;
a controller that controls the power source so that the plurality of energy pulses overlap and combine to produce a composite energy pulse having a composite pulse shape;
a light guide that receives the composite energy pulse, the light guide emitting light energy in a direction away from the light guide to generate a plasma pulse away from the light guide;
an inflatable balloon that encircles a distal end of the light guide; and a nano surface that is positioned near the distal end of the light guide,
wherein the catheter system is configured to generate a pre-bubble at the distal end of the light guide so that the plasma pulse is generated away from the light guide.