Treating tissue pulsed energy using high-voltage catheters
Flexible catheters adapted to be inserted into a body to deliver high-voltage, fast (e.g., microsecond, sub-microsecond, nanosecond, picosecond, etc.) electrical energy to target tissue may include a plurality of conductive layers, that may be coaxial. These catheters and method of using them to treat tissue are configured to reduce or avoid arcing.
1. A method of treating tissue, the method comprising:
applying a plurality of electrical pulses having an amplitude of greater than 0.1 kV to a proximal end of a catheter inserted into a body of a subject through a first conductive layer formed from a first plurality of braided or woven filaments extending at least partially down a length of the catheter and through a second conductive layer extending coaxial to the first conductive layer; and
delivering the plurality of electrical pulses to the body of the subject from a first electrode at a distal end region of the catheter in electrical communication with the first conductive layer and a second electrode at the distal end region of the catheter in electrical communication with the second conductive layer,
wherein the first and second conductive layers are configured to prevent electromagnetic interference (EMI) arising from the first and second conductive layers at high voltages and rapid pulse rates.
2. The method of claim 1 , further comprising connecting the catheter to a pulse generator using a high-voltage connector.
3. The method of claim 1 , further comprising driving the distal end region of the catheter against the tissue so that the first and second electrodes contact the tissue.
4. The method of claim 1 , further comprising inflating an inflatable balloon on a side of the distal end region of the catheter.
5. The method of claim 1 , wherein each of the plurality of electrical pulses has a duration of 1000 ns or less.
6. The method of claim 1 , wherein the plurality of electrical pulses has peak voltages of between about 1 kV/cm and 100 kV/cm.
7. The method of claim 1 , wherein the first and second conductive layers are enclosed by a flexible insulating material having a dielectric strength sufficient to withstand 1 kV or more.
8. The method of claim 1 , the method comprising a treatment of a cardiac tissue, esophageal tissue, lung tissue, bronchial passages, skin, or ablation of tumors.
9. The method of claim 1 , wherein the method is to treat an epicardial, endocardial, and/or pericardial tissue, the method comprising positioning the catheter within or near a target region of a heart.
10. The method of claim 1 , wherein at least one of the applying and delivering is performed by a robotic system.
11. The method of claim 1 , further comprising checking an impedance between the first electrode and the second electrode prior to and/or while applying the plurality of electrical pulses and suspending the applying of the plurality of electrical pulses until the impedance exceeds an impedance threshold.
12. The method of claim 1 , further comprising periodically or continuously checking an impedance between the first electrode and the second electrode during the applying of the plurality of electrical pulses and stopping or suspending the applying if the impedance falls below an impedance threshold or exceeds the impedance threshold.
13. The method of claim 1 , the method comprising articulating at least some portion of the catheter by pulling and/or pushing one or more tendons or by using a bendable steering element in a lumen of the catheter.
14. The method of claim 1 , wherein the method is for laparoscopic or endoscopic applications.
15. The method of claim 1 , wherein at least one of the first electrode and the second electrode comprises one or more sets of electrodes and wherein the method comprises actuating the one or more sets of electrodes separately.
16. A method of delivering pulsed power to a catheter, the method comprising:
allowing to connect or connecting a high-voltage connector to a first conductive layer and a second conductive layer of the catheter, the first conductive layer formed from a first one or more braided or woven filaments extending down at least a portion of a length of an elongate body of the catheter, the second conductive layer extending coaxial to the first conductive layer; and
applying a plurality of electrical pulses having an amplitude of 1 kV or more from the high-voltage connector through the first and second conductive layers,
wherein the first and second conductive layers are insulated by a flexible insulating material and the first and second conductive layers are configured to prevent electromagnetic interference (EMI) arising from the first and second conductive layers at high voltages and rapid pulse rates.
17. The method of claim 16 , the method comprising emitting one or a pattern of test pulses to detect at least one property of electrical pathway.
18. The method of claim 16 , further comprising periodically or continuously checking an impedance between a first electrode at a distal end region of the catheter and a second electrode during the applying of the plurality of electrical pulses and stopping or suspending the applying if the impedance falls below an impedance threshold or exceeds the impedance threshold.
19. The method of claim 16 , further comprising preventing energy from being applied through the high-voltage connector by one or more interlocks of the high-voltage connector until a sealing contact is ensured.
20. The method of claim 19 , wherein ensuring the contact is performed by applying a low-power signal and determining a stability of a connection by detecting impedance or other electrical property.
21. The method of claim 16 , further comprising connecting the catheter to a pulse generator through the high-voltage connector, wherein the pulse generator is configured to generate sub-microsecond pulses.
22. The method of claim 16 , further comprising periodically or continuously checking an impedance between a first electrode and a second electrode of the catheter to determine whether a location of the first and second electrodes is outside of a target tissue.
23. The method of claim 16 , further comprising delivering pulsed power from the catheter to a cardiac tissue.