Optical analyzer assembly and method for intravascular lithotripsy device
A catheter system for treating a treatment site within or adjacent to a vessel wall includes a light source, a balloon, a light guide, and an optical analyzer assembly. The light source generates light energy. The balloon is positionable substantially adjacent to the vascular lesion. The balloon has a balloon wall that defines a balloon interior that receives a balloon fluid. The light guide receives light energy from the light source at a guide proximal end and guides the light energy toward a guide distal end and into the balloon interior. The optical analyzer assembly is configured to optically analyze light energy emitted from the guide proximal end of the light guide.
1 . A catheter system for treating a treatment site within or adjacent to a vessel wall or a heart valve, the catheter system being configured to use a balloon fluid, the catheter system comprising:
a light source that generates light energy;
a balloon that is positionable substantially adjacent to the treatment site, the balloon having a balloon wall that defines a balloon interior, the balloon interior being configured to receive the balloon fluid;
a light guide that is configured to receive the light energy from the light source at a guide proximal end and guide the light energy so that the light energy from the light source moves through the light guide in a first direction from the guide proximal end toward a guide distal end that is positioned within the balloon interior, the light energy from the light source that moves through the light guide in the first direction being configured to generate plasma in the balloon fluid within the balloon interior, the guide distal end of the light guide being in fluid communication with the balloon fluid in which the plasma is configured to be generated, the light guide being configured to subsequently guide a portion of the light energy from the light source that is configured to generate the plasma in the balloon fluid within the balloon interior back through the light guide from the guide distal end to the guide proximal end in a second direction that is opposite the first direction, the portion of the light energy that is guided back through the light guide in the second direction being emitted from the plasma that is generated in the balloon fluid within the balloon interior; and
an optical analyzer assembly that is configured to optically analyze the portion of the light energy from the guide proximal end of the light guide that moved back through the light guide in the second direction.
2 . The catheter system of claim 1 wherein the light source generates pulses of light energy that induce the plasma generation in the balloon fluid within the balloon interior.
3 . The catheter system of claim 1 wherein the optical analyzer assembly is configured to optically detect a failure of the light guide at any point along a length of the light guide from the guide proximal end to the guide distal end.
4 . The catheter system of claim 1 wherein the optical analyzer assembly is configured to optically detect damage to the light guide at any point along a length of the light guide from the guide proximal end to the guide distal end.
5 . The catheter system of claim 4 wherein the optical analyzer assembly is configured to automatically shut down operation of the catheter system upon optical detection of damage to the light guide.
6 . The catheter system of claim 1 wherein second light energy including the portion of the light energy from the energy source is guided back through the light guide in the second direction as a returning energy beam, the optical analyzer assembly being configured to optically analyze the returning energy beam to determine when the plasma generation occurred in the balloon fluid within the balloon interior.
7 . The catheter system of claim 6 wherein the optical analyzer assembly includes a beamsplitter and a photodetector, the beamsplitter being configured to receive the returning energy beam and direct at least a portion of the returning energy beam to the photodetector.
8 . The catheter system of claim 7 further comprising an optical element that is positioned along a beam path between the beamsplitter and the photodetector, the optical element being configured to couple the at least a portion of the returning energy beam onto the photodetector.
9 . The catheter system of claim 7 wherein the photodetector generates a signal based at least in part on visible light that is included with the at least a portion of the returning energy beam.
10 . The catheter system of claim 9 further comprising an amplifier and control electronics; and wherein the signal from the photodetector is amplified with the amplifier to provide an amplified signal that is directed to the control electronics to determine an intensity of the plasma generation within the balloon interior.
11 . The catheter system of claim 10 wherein the amplified signal is gated using a discriminator circuit, the control electronics being configured to compare a timing of a pulse of light energy from the light source as triggered by a pulse generator with a timing of the amplified signal from the photodetector to determine when the plasma generation occurred within the balloon interior.
12 . The catheter system of claim 1 wherein the light source includes a laser.
13 . The catheter system of claim 1 wherein the light source includes an infrared laser that emits light energy in the form of pulses of infrared light.
14 . The catheter system of claim 1 wherein the light guide includes an optical fiber.
15 . The catheter system of claim 1 wherein the balloon has a drug eluting coating.
16 . The catheter system of claim 1 wherein the balloon interior receives the balloon fluid so that the balloon is inflated with the balloon fluid to an expanded configuration; and wherein the plasma is generated in the balloon fluid that is used to inflate the balloon to the expanded configuration.
17 . The catheter system of claim 1 wherein the portion of the light energy from the light source that moves back through the light guide from the guide distal end to the guide proximal end includes broad-spectrum light energy emitted from the plasma that is coupled back into the guide distal end of the light guide.
18 . A catheter system for treating a treatment site within or adjacent to a vessel wall or a heart valve, the catheter system being configured to use a balloon fluid, the catheter system comprising:
a light source that generates light energy;
a balloon that is positionable substantially adjacent to the treatment site, the balloon having a balloon wall that defines a balloon interior, the balloon interior being configured to receive the balloon fluid to expand the balloon to an expanded configuration;
a light guide that is configured to receive the light energy from the light source at a guide proximal end and guide the light energy so that the light energy from the light source moves through the light guide in a first direction from the guide proximal end toward a guide distal end that is positioned within the balloon interior, the light energy from the light source that moves through the light guide in the first direction being configured to generate plasma in the balloon fluid within the balloon interior that has been used to expand the balloon to the expanded configuration, the light guide being configured to subsequently guide a portion of the light energy from the light source that is configured to generate the plasma in the balloon fluid within the balloon interior that has been used to expand the balloon to the expanded configuration back through the light guide from the guide distal end to the guide proximal end in a second direction that is opposite the first direction, the portion of the light energy that is guided back through the light guide in the second direction being emitted from the plasma that is generated in the balloon fluid within the balloon interior; and
an optical analyzer assembly that is configured to optically analyze the portion of the light energy from the guide proximal end of the light guide that moved back through the light guide in the second direction.
19 . The catheter system of claim 18 , wherein the light source generates pulses of light energy; and wherein the light guide is configured to guide the pulses of light energy into the balloon interior to induce the plasma generation in the balloon fluid within the balloon interior that has been used to expand the balloon to the expanded configuration.
20 . The catheter system of claim 18 further comprising a pulse generator that is coupled to the light source, the pulse generator triggering the light source to emit pulses of light energy that are guided along the light guide from the guide proximal end to the guide distal end, the pulses of light energy being emitted from the guide distal end of the light guide into the balloon fluid within the balloon interior to generate the plasma in the balloon fluid within the balloon interior that has been used to expand the balloon to the expanded configuration.
21 . The catheter system of claim 18 wherein the light guide guides the portion of the light energy back through the light guide to the guide proximal end as a returning energy beam; and wherein the optical analyzer assembly optically analyzes the returning energy beam to determine when the plasma generation occurred in the balloon fluid within the balloon interior that has been used to expand the balloon to the expanded configuration.
22 . The catheter system of claim 21 wherein the optical analyzer assembly includes a beamsplitter and a photodetector, the beamsplitter being configured to receive the returning energy beam and direct at least a portion of the returning energy beam onto the photodetector.
23 . The catheter system of claim 18 wherein the light source includes a laser; and wherein the light guide includes an optical fiber.
24 . The catheter system of claim 18 wherein the portion of the light energy from the light source that moves back through the light guide from the guide distal end to the guide proximal end including broad-spectrum light energy emitted from the plasma that is coupled back into the guide distal end of the light guide.