HEATING/SENSING CATHETER APPARATUS FOR MINIMALLY INVASIVE APPLICATION

• US 20140018697A1
• Filed: 09/20/2013
• Published: 01/16/2014
• Est. Priority Date: 04/19/2012
• Status: Abandoned Application

• Current Assignee: Coral Sand Beach, LLC
• Original Assignee: Meridian Medical Systems LLC
• Inventors: Allison, Robert C.
• Application Number:
  US14/032,315
• Publication Number:
  US 20140018697A1
• Time in Patent Office: Days
• US Class Current: 600/549
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00791 Temperature
• CPC Class Codes: A61B 2018/1861 with an instrument inserted into a body lumen or cavity, e.g. a catheter
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61N 1/403 for thermotherapy, e.g. hyperthermia
• CPC Class Codes: A61N 5/025 Warming the body, e.g. hyperthermia treatment
• CPC Class Codes: A61N 5/045 specially adapted for treatment inside the body

Abstract

Catheter apparatus comprises a coaxial cable having proximal and distal ends. The cable includes a hollow center conductor, an outer conductor and an electrically insulating layer between the conductors. An antenna is at the distal end of the cable, and a diplexer is connected to the cable, the diplexer including a transmit path for connecting the antenna to a transmitter which transmits first frequency signals and a receive path for connecting the antenna to a receiver which detects second frequency signals the diplexer isolating the signals on the two paths from one another. A transmission line connects the cable to the diplexer, the transmission line having a segment with a tubular inner conductor one end of which is connected to the center conductor and a second end of which is adapted for connection to a coolant source, the center and inner conductors forming a continuous coolant pathway.

Claims

1. Catheter apparatus comprising

an elongated flexible coaxial cable having proximal and distal ends, said cable including a hollow center conductor, an outer conductor and an electrically insulating layer in an annular space between said conductors;

an antenna at the distal end of the cable;

a diplexer including a transmit path for connecting the antenna to a transmitter which transmits signals of a first frequency and a receive path for connecting the antenna to a receiver which detects signals of a second frequency, said diplexer isolating the signals on the two paths from one another;

a transmission line connecting the cable to the diplexer, said transmission line including a segment with a tubular inner conductor one end of which is connected to the center conductor of the cable and a second end of which is adapted for connection to a coolant source, said center conductor and said inner conductor forming a continuous coolant pathway.

2. The apparatus defined in claim 1 wherein said receive path includes a first electrical filter.

3. The apparatus defined in claim 1 and further including an impedance-matching transformer in series with the cable and the transmission line.

4. The apparatus defined in claim 1 wherein the cable outer conductor comprises braided conductive strands.

5. The apparatus defined in claim 1 wherein the cable insulating layer comprises a flexible winding of one or more dielectric strands having multiple fluid flow paths therebetween.

6. The apparatus defined in claim 1 wherein said antenna comprises an extension of the center conductor beyond the outer conductor and the insulating layer.

7. The apparatus defined in claim 6 wherein said extension is tubular and continues said fluid pathway to the outside.

8. The apparatus defined in claim 1 wherein said antenna is connected to the center conductor via a connection device at the distal end of the cable.

9. The apparatus defined in claim 8 wherein the connection device defines a fluid path between the interior of the center conductor and the outside.

10. The apparatus defined in claim 1 wherein the antenna is flexible.

11. The apparatus defined in claim 1 and further including a stand-off device adjacent to the distal end of the cable for centering said antenna in a body passage.

12. The apparatus defined in claim 1 and further including one or more temperature detectors positioned in said fluid pathway for monitoring coolant temperature at one or more locations therealong.

13. The apparatus defined in claim 1 and further including a microwave or RF transmitter connected to said transmit path.

14. The apparatus defined in claim 1 and further including a coolant source connected to said second end of the tubular inner conductor of said transmission line segment.

15. The apparatus defined in claim 1 wherein said cable and said diplexer are formed as a unitary disposable first part designed for connection both electrically and mechanically to a mating reusable second part containing microwave receiver.