Tunable microwave ablation catheter system and method

Claim 2

A medical catheter comprising: a flexible tubular member adapted to be inserted into a vessel in the body of a patient; a coaxial transmission line disposed within the tubular member, the transmission line having proximal and distal ends and a center conductor, a dielectric material journaled about the center conductor and a shield, wherein the proximal end of the transmission line is suitable for connection to a microwave energy source; an antenna carried by the distal end of the transmission line for generating an electric field sufficiently strong to cause tissue ablation; and means for mechanically altering the impedance of the transmission line during use in a controlled manner to facilitate tuning the catheter by compensating for variations in the effective impedance of the catheter that occur during use.

Claim 3

A catheter as recited in claim 1 wherein said impedance altering means includes a coaxial tuner coupled to the transmission line.

Claim 4

A catheter as recited in claim 2 wherein said coaxial tuner is a capacitive tuner.

Claim 5

A catheter as recited in claim 1 wherein said impedance altering means includes a double coaxial tuner coupled to the transmission line for mechanically altering said effective impedance.

Claim 6

A medical catheter tuning system that includes a power supply having a microwave generator and microwave transmission means, a catheter having a microwave transmission line suitable for coupling to said transmission means and a microwave antenna for creating a microwave field, the tuning system comprising: means for monitoring the amount of power that is reflected from the catheter during use; and a tuner arranged to facilitate dynamically matching the impedance of a power generator side portion of the catheter system with a catheter side portion of the catheter system during use of the catheter, the tuner being arranged to mechanically alter the effective impedance of a microwave energy transmitting portion of the catheter system during use of the catheter to compensate for variations in effective impedance that occur during use.

Claim 7

A medical catheter tuning system that includes a power supply having a microwave generator and microwave transmission means, a catheter having a microwave transmission line suitable for coupling to said transmission means and a microwave antenna for creating a microwave field, the tuning system comprising: means for monitoring the amount of power that is reflected from the catheter during use; and a tuner arranged to facilitate dynamically matching the impedance of a power generator side portion of the catheter system with a catheter side portion of the catheter system during use of the catheter, the tuner being arranged to mechanically alter the effective impedance of a microwave energy transmitting portion of the catheter system during use of the catheter to compensate for variations in effective impedance that occur during use.

Claim 8

A tuning system as recited in claim 5 wherein the tuner includes a manually adjustable control knob that can be accessed by a user to manually adjust the effective impedance of the catheter side portion of the catheter system.

Claim 9

A tuning system as recited in claim 5 wherein the tuner is responsive to changes in the power reflected from the catheter during use of the catheter and automatically matches the impedance of the power generator side portion of the catheter system with a catheter side portion of the catheter system.

Claim 10

A tuning system as recited in claim 5 further comprising a display for displaying an indication of the magnitude of the reflected power and wherein the reflected power monitoring means includes a directional coupler and power sensor, an output of the power sensor being electrically coupled to the display.

Claim 11

A microwave ablation catheter system comprising: an elongated catheter tubing having at least one lumen wherein; a coaxial microwave transmission line that passes through the lumen; a insulated antenna carried at the distal end of the transmission line; a microwave generator for generating microwave energy having a frequency in the range of approximately 800 MHz-3 Ghz; transmission means for coupling the microwave generator to the coaxial transmission line; a tuner arranged for dynamically matching the impedance of a microwave generator side portion of the catheter system with a catheter side portion of the catheter system during use of the catheter wherein tuning is accomplished by altering the effective impedance of one of said transmission means, said antenna and said coaxial transmission line; and means for continuously monitoring the amount of power transmitted to and reflected from the catheter side portion of the ablation catheter system during use, wherein indicia of the transmitted and reflected power are available to facilitate tuning using said tuner.

Claim 12

A microwave ablation catheter system comprising: an elongated catheter tubing having at least one lumen wherein; a coaxial microwave transmission line that passes through the lumen; a insulated antenna carried at the distal end of the transmission line; a microwave generator for generating microwave energy having a frequency in the range of approximately 800 MHz-3 Ghz; transmission means for coupling the microwave generator to the coaxial transmission line; a tuner arranged for dynamically matching the impedance of a microwave generator side portion of the catheter system with a catheter side portion of the catheter system during use of the catheter wherein tuning is accomplished by altering the effective impedance of one of said transmission means, said antenna and said coaxial transmission line; and means for continuously monitoring the amount of power transmitted to and reflected from the catheter side portion of the ablation catheter system during use, wherein indicia of the transmitted and reflected power are available to facilitate tuning using said tuner.

Claim 13

A microwave ablation catheter system as recited in claim 9 wherein the tuner includes a manually adjustable control knob that can be accessed by a user to manually adjust the effective impedance of the catheter side portion of the catheter system.

Claim 14

A microwave ablation catheter system as recited in claim 9 wherein the tuner is responsive to the power monitor means and automatically matches the impedance of the power generator side portion of the catheter system with a catheter side portion of the catheter system during use of the catheter system.

Claim 15

A microwave ablation catheter system as recited in claim 9 further comprising: an interlock system for automatically shutting off the microwave energy generator when certain predefined safety hazards are detected; and a display for displaying an indication of the magnitude of the reflected power; and wherein the power monitoring means includes a pair of directional couplers and a pair of power sensors.

Claim 16

A catheter system comprising: an elongated tubular member suitable for insertion into a vessel in the body of a patient, the tubular member having at least one lumen therein; a coaxial catheter waveguide received in the lumen; an electromagnetic energy generator; transmission means for coupling the electromagnetic energy generator to the catheter waveguide, an antenna carried by the waveguide for generating an electromagnetic field when electromagnetic energy produced by said generator is applied thereto via the transmission means and the waveguide, whereby the electromagnetic field may be used for interventional medical procedures, the elongated tubular member, the waveguide and the antenna cooperating to form a catheter; a reflected power monitoring means for continuously monitoring the electromagnetic energy that is reflected from the catheter during use and outputting a signal indicative of the reflected power; and tuning means for adjusting the impedance of a component of the catheter system, whereby the tuning means is suitable for use to reduce the reflected power that occurs during use of the catheter system in an interventional medical procedure, the tuner means being arranged to facilitate impedance matching of the catheter system during use.

Claim 17

A catheter system comprising: an elongated tubular member suitable for insertion into a vessel in the body of a patient, the tubular member having at least one lumen therein; a coaxial catheter waveguide received in the lumen; an electromagnetic energy generator; transmission means for coupling the electromagnetic energy generator to the catheter waveguide, an antenna carried by the waveguide for generating an electromagnetic field when electromagnetic energy produced by said generator is applied thereto via the transmission means and the waveguide, whereby the electromagnetic field may be used for interventional medical procedures, the elongated tubular member, the waveguide and the antenna cooperating to form a catheter; a reflected power monitoring means for continuously monitoring the electromagnetic energy that is reflected from the catheter during use and outputting a signal indicative of the reflected power; and tuning means for adjusting the impedance of a component of the catheter system, whereby the tuning means is suitable for use to reduce the reflected power that occurs during use of the catheter system in an interventional medical procedure, the tuner means being arranged to facilitate impedance matching of the catheter system during use.

Claim 18

An ablution catheter system comprising: an elongated tubular member suitable for insertion into a vessel in the body of a patient, the tubular member having at least one lumen therein; a waveguide received in the lumen; an microwave energy generator; transmission means for coupling the microwave energy generator to the catheter waveguide, an antenna carried by the waveguide for generating an electromagnetic field when electromagnetic energy produced by said generator is applied thereto via the transmission means and the waveguide, whereby the electromagnetic field may be used for interventional medical procedures, the elongated tubular member, the waveguide and the antenna cooperating to form a catheter; a reflected power monitoring means for monitoring the electromagnetic energy that is reflected from the catheter during use and outputting a signal indicative of the reflected power; and tuning means for mechanically adjusting the impedance of a component of the catheter system, whereby the tuning means is suitable for use to reduce the reflected power that occurs during use of the catheter system in an interventional medical procedure, the tuner means being arranged to facilitate matching the impedance of a power generator side portion of the catheter system with a catheter side portion of the catheter system.

Claim 19

An ablution catheter system comprising: an elongated tubular member suitable for insertion into a vessel in the body of a patient, the tubular member having at least one lumen therein; a waveguide received in the lumen; an microwave energy generator; transmission means for coupling the microwave energy generator to the catheter waveguide, an antenna carried by the waveguide for generating an electromagnetic field when electromagnetic energy produced by said generator is applied thereto via the transmission means and the waveguide, whereby the electromagnetic field may be used for interventional medical procedures, the elongated tubular member, the waveguide and the antenna cooperating to form a catheter; a reflected power monitoring means for monitoring the electromagnetic energy that is reflected from the catheter during use and outputting a signal indicative of the reflected power; and tuning means for mechanically adjusting the impedance of a component of the catheter system, whereby the tuning means is suitable for use to reduce the reflected power that occurs during use of the catheter system in an interventional medical procedure, the tuner means being arranged to facilitate matching the impedance of a power generator side portion of the catheter system with a catheter side portion of the catheter system.

Claim 20

A medical catheter comprising: a flexible tubular member adapted to be inserted into a vessel in the body of patient; a coaxial transmission line disposed within the tubular member, the transmission line having proximal and distal ends, wherein the proximal end of the transmission line is suitable for connection to a microwave energy source; an antenna carried by the distal end of the transmission line for generating an electric field sufficiently strong to cause tissue ablation; and means for mechanically altering the effective impedance of the antenna during use in a controlled manner to facilitate tuning the catheter by compensating for variations in the effective impedance of the catheter that occur during use.

Claim 21

A medical catheter comprising: a flexible tubular member adapted to be inserted into a vessel in the body of patient; a coaxial transmission line disposed within the tubular member, the transmission line having proximal and distal ends, wherein the proximal end of the transmission line is suitable for connection to a microwave energy source; an antenna carried by the distal end of the transmission line for generating an electric field sufficiently strong to cause tissue ablation; and means for mechanically altering the effective impedance of the antenna during use in a controlled manner to facilitate tuning the catheter by compensating for variations in the effective impedance of the catheter that occur during use.

Claim 22

A medical catheter system comprising: a catheter as recited in claim 15; a power supply that serves as said energy source, the power supply having an electromagnetic energy generator capable of generating radio frequency energy at said predetermined wavelength; and a connector for coupling the electromagnetic energy generator to the transmission line.

Claim 23

A catheter system as recited in claim 16 further comprising means for detecting power reflected from the catheter side of the catheter system and the means for altering the impedance of the antenna includes a tuner controller that is arranged to alter the impedance of the catheter during use to minimize reflected power.

Claim 24

A microwave ablution catheter system power supply that includes an ablation catheter having a waveguide and an antenna carried by the waveguide, the ablation catheter being coupled to the power supply by a connector arrangement the power supply comprising: a microwave energy generator for generating electromagnetic energy having a frequency in the microwave range, the microwave energy generator being coupled to the catheter waveguide through a transmission line and said connector; a reflected power monitor in communication with one of said catheter waveguide and said transmission line, for monitoring the amount of power that is reflected from the catheter during use and outputting a signal indicative of the reflected power; and tuner means in communication with one of said transmission line, said catheter waveguide and said antenna, the tuner means being arranged to facilitate dynamically matching the impedance of a power generator side portion of the catheter system with the impedance of a catheter side portion of the catheter system during use of the catheter, wherein the impedance is mechanically adjusted.

Claim 25

A microwave ablution catheter system power supply that includes an ablation catheter having a waveguide and an antenna carried by the waveguide, the ablation catheter being coupled to the power supply by a connector arrangement the power supply comprising: a microwave energy generator for generating electromagnetic energy having a frequency in the microwave range, the microwave energy generator being coupled to the catheter waveguide through a transmission line and said connector; a reflected power monitor in communication with one of said catheter waveguide and said transmission line, for monitoring the amount of power that is reflected from the catheter during use and outputting a signal indicative of the reflected power; and tuner means in communication with one of said transmission line, said catheter waveguide and said antenna, the tuner means being arranged to facilitate dynamically matching the impedance of a power generator side portion of the catheter system with the impedance of a catheter side portion of the catheter system during use of the catheter, wherein the impedance is mechanically adjusted.

Claim 26

A power supply as recited in claim 18 wherein: the tuner includes a manually adjustable control knob that can be accessed by a user to manually adjust the impedance of the catheter side portion of the catheter system; and the reflected power monitor further includes a display for displaying an indicia indicative of the reflected power to the user to facilitate manual adjustment of the control knob, the indicia being based at least in part on the output signal.

Claim 27

A power supply as recited in claim 18 wherein: the tuner automatically matches the impedance of the power generator side portion of the catheter system with a catheter side portion of the catheter system; and the tuner further includes a tuner controller that receives the signal indicative of the reflected power from the reflected power monitor and generates a control signal based at least in part on the signal indicative of the reflected power.

Claim 28

A power supply as recited in claim 18 wherein tuner includes a stub tuner coupled to the transmission line for impedance matching of the power supply portion of the catheter system to the catheter side portion of the catheter system.

Claim 29

A power supply as recited in claim 18 further comprising a display that receives said signal for providing the user with an indication of the magnitude of the reflected power.

Claim 30

A power supply as recited in claim 18 wherein the tuner means includes a stub tuner which accomplishes the mechanical impedance adjusting.

Claim 31

A medical catheter tuning system that includes a power supply having a microwave generator and microwave transmission means, a catheter having a microwave transmission line suitable for coupling to said transmission means and a microwave antenna for creating a microwave field, the tuning system comprising: means for monitoring the amount of power that is reflected from the catheter during use; and a tuner arranged to facilitate matching the impedance of a power generator side portion of the catheter system with a catheter side portion of the catheter system based at least in part upon the monitored reflected power, the tuner being arranged to mechanically alter the effective impedance of a microwave energy transmitting portion of the catheter system.

Claim 32

A medical catheter tuning system that includes a power supply having a microwave generator and microwave transmission means, a catheter having a microwave transmission line suitable for coupling to said transmission means and a microwave antenna for creating a microwave field, the tuning system comprising: means for monitoring the amount of power that is reflected from the catheter during use; and a tuner arranged to facilitate matching the impedance of a power generator side portion of the catheter system with a catheter side portion of the catheter system based at least in part upon the monitored reflected power, the tuner being arranged to mechanically alter the effective impedance of a microwave energy transmitting portion of the catheter system.

Claim 33

A medical catheter tuning system that includes a power supply having a microwave generator and microwave transmission means, a catheter having a microwave transmission line suitable for coupling to said transmission means and a microwave antenna for creating a microwave field, the tuning system comprising: means for continuously monitoring the mount of power that is reflected from the catheter during use; and a tuner arranged to facilitate matching the impedance of a power generator side portion of the catheter system with a catheter side portion of the catheter system based at least in part upon the continuously monitored reflected power, the tuner being arranged to alter the effective impedance of a microwave energy transmitting portion of the catheter system.

Claim 34

A medical catheter tuning system that includes a power supply having a microwave generator and microwave transmission means, a catheter having a microwave transmission line suitable for coupling to said transmission means and a microwave antenna for creating a microwave field, the tuning system comprising: means for continuously monitoring the mount of power that is reflected from the catheter during use; and a tuner arranged to facilitate matching the impedance of a power generator side portion of the catheter system with a catheter side portion of the catheter system based at least in part upon the continuously monitored reflected power, the tuner being arranged to alter the effective impedance of a microwave energy transmitting portion of the catheter system.

Claim 35

A medical catheter tuning system that includes a power supply having a microwave generator and microwave transmission means, a catheter having a microwave transmission line suitable for coupling to said transmission means and a microwave antenna for creating a microwave field, the tuning system comprising: means for continuously monitoring the amount of power that is reflected from the catheter during use; and a tuner arranged to facilitate periodically matching the impedance of a power generator side portion of the catheter system with a catheter side portion of the catheter system during use of the catheter, the tuner being arranged to alter the effective impedance of a microwave energy transmitting portion of the catheter system during use of the catheter to compensate for variations in effective impedance that occur during use.

Claim 36

A medical catheter tuning system that includes a power supply having a microwave generator and microwave transmission means, a catheter having a microwave transmission line suitable for coupling to said transmission means and a microwave antenna for creating a microwave field, the tuning system comprising: means for continuously monitoring the amount of power that is reflected from the catheter during use; and a tuner arranged to facilitate periodically matching the impedance of a power generator side portion of the catheter system with a catheter side portion of the catheter system during use of the catheter, the tuner being arranged to alter the effective impedance of a microwave energy transmitting portion of the catheter system during use of the catheter to compensate for variations in effective impedance that occur during use.

Claim 37

A tuning system as recited in claim 26 wherein the tuner includes a manually adjustable control knob that can be accessed by a user to manually adjust the effective impedance of the catheter side portion of the catheter system.

Claim 38

A tuning system as recited in claim 26 wherein the tuner is responsive to changes in the power reflected from the catheter during use of the catheter and automatically matches the impedance of the power generator side portion of the catheter system with a catheter side portion of the catheter system.

Claim 39

A microwave ablution catheter system comprising: an elongated catheter tubing having at least one lumen therein; a coaxial microwave transmission line that passes through the lumen; a insulated antenna carried at the distal end of the transmission line; a microwave generator for generating microwave energy having a frequency in the range of approximately 800 MHz-3 Ghz; transmission means for coupling the microwave generator to the coaxial transmission line; a tuner arranged for periodically matching the impedance of a microwave generator side portion of the catheter system with a catheter side portion of the catheter system during use of the catheter, wherein tuning is accomplished by altering the effective impedance of one of said transmission means, said antenna and said coaxial transmission line; and means for continuously monitoring the amount of power transmitted to and reflected from the catheter side portion of the ablation catheter system during use, wherein indicia of the transmitted and reflected power are available to facilitate tuning using said tuning means.

Claim 40

A microwave ablution catheter system comprising: an elongated catheter tubing having at least one lumen therein; a coaxial microwave transmission line that passes through the lumen; a insulated antenna carried at the distal end of the transmission line; a microwave generator for generating microwave energy having a frequency in the range of approximately 800 MHz-3 Ghz; transmission means for coupling the microwave generator to the coaxial transmission line; a tuner arranged for periodically matching the impedance of a microwave generator side portion of the catheter system with a catheter side portion of the catheter system during use of the catheter, wherein tuning is accomplished by altering the effective impedance of one of said transmission means, said antenna and said coaxial transmission line; and means for continuously monitoring the amount of power transmitted to and reflected from the catheter side portion of the ablation catheter system during use, wherein indicia of the transmitted and reflected power are available to facilitate tuning using said tuning means.

Claim 41

A microwave ablation catheter system as recited in claim 29 wherein the tuner is responsive to the power monitor means and automatically matches the impedance of the power generator side portion of the catheter system with a catheter side portion of the catheter system during use of the catheter system.

Claim 44

A method as recited in claim 31 further comprising the step of monitoring the reflected power from the catheter and using the relative magnitude of the reflected power to determine the appropriate impedance adjustments.

Claim 45

A method as recited in claim 32 further comprising a step of monitoring the catheter for the existence of dangerous conditions and shutting off the microwave power source in the event of the detection of a dangerous condition, wherein a sudden change in the magnitude of the reflected power and extreme values are interpreted as dangerous conditions.

Claim 46

A method as recited in claim 31 wherein the step of adjusting the relative impedance is done manually.

Claim 47

A method as recited in claim 31 wherein the step of adjusting the relative impedance is done automatically.

Claim 48

A method as recited in claim 31 wherein the tuning is done by modulating the antenna.

Claim 49

A method as recited in claim 31 wherein the tuning is done by modulating the microwave waveguide.

Claim 50

A method as recited in claim 36 wherein a thrust plate is positioned adjacent the antenna and the antenna is modulated by longitudinally moving the thrust plate to compress or extend the antenna.

Claim 51

A method as recited in claim 31 wherein the tuning is done by inflating a balloon in the catheter.

Claim 52

A method as recited in claim 39 wherein the balloon is arranged to deflect the microwave waveguide.