ECHOGENIC NEEDLE CATHETER CONFIGURED TO PRODUCE AN IMPROVED ULTRASOUND IMAGE

• US 20100331697A1
• Filed: 09/14/2010
• Published: 12/30/2010
• Est. Priority Date: 12/02/2005
• Status: Active Grant

• Current Assignee: Mina Chow, William E. Webler
• Original Assignee: Mina Chow, William E. Webler
• Inventors: Chow, Mina, Webler, William E.
• Granted Patent: US 8,303,509 B2
• Time in Patent Office: Days
• US Class Current: 600/443
• CPC Class Codes: A61B 2090/3782 transmitter or receiver in catheter or minimal invasive instrument
• CPC Class Codes: A61B 8/0841 for locating instruments
• CPC Class Codes: A61B 90/36 Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: A61M 2025/0089 Single injection needle protruding axially, i.e. along the longitudinal axis of the catheter, from the distal tip
• CPC Class Codes: A61M 25/0009 Making of catheters or other medical or surgical tubes
• CPC Class Codes: A61M 25/0045 multi-layered, e.g. coated coating materials A61L29/08
• CPC Class Codes: A61M 25/0052 Localized reinforcement, e.g. where only a specific part of the catheter is reinforced, for rapid exchange guidewire port
• CPC Class Codes: A61M 25/0068 Static characteristics of the catheter tip, e.g. shape, atraumatic tip, curved tip or tip structure
• CPC Class Codes: A61M 25/0069 Tip not integral with tube
• CPC Class Codes: A61M 25/0084 being one or more injection needles
• CPC Class Codes: A61M 25/0108 using radio-opaque or ultrasound markers
• CPC Class Codes: A61M 25/0147 with movable mechanical means, e.g. pull wires

Abstract

An echogenic medical device, such as a needle catheter, which produces an improved ultrasonic image of the device, and a method of performing a medical procedure using a device of the invention. One aspect is directed to a catheter which reduces artifacts in the ultrasound image of the catheter. In one embodiment, the catheter has a spherical distal tip. Another aspect of the invention is directed to an echogenic catheter with echogenic portions arranged in an array to facilitate determination by ultrasonic imaging of the rotational orientation of the catheter relative to a desired location within the patient.

Claims

1. A method of performing a medical procedure, comprising:

a) advancing within a patient'"'"'s anatomy an echogenic needle catheter, comprising

i) an elongated shaft having a proximal end, a distal end, and a needle lumen;

ii) a spherical distal tip at the distal end of the elongated shaft, having a lumen in communication with the needle lumen of the shaft and with a port at a distal end of the spherical distal tip; and

iii) a needle in the needle lumen, which extends distally from the spherical distal tip port in an extended configuration, and which has a lumen; and

b) directing sonic energy at the catheter from an ultrasonic imaging system, such that the spherical distal tip more diffusely reflects the sonic energy than a nonspherical distal tip, to produce an ultrasonic image of the spherical distal tip.

2. The method of claim 1 wherein the spherical distal tip is formed at least in part of a metallic material and is electrically connected to a conductor so that the spherical distal tip is an electrode.

3. The method of claim 2 wherein the spherical distal tip is formed in part of a damping plastic material, and including dissipating the sonic energy within the damping plastic material of the spherical distal tip, so that the ultrasonic image of the distal tip has a less bright and long pyramid artifact than a metallic tip formed without the damping plastic material.

4. The method of claim 1 wherein the catheter shaft comprises a proximal shaft section and a distal shaft section, and including an electrode on the proximal shaft section a sufficient distance from the distal tip that an ultrasonic image of the electrode does not over lap with the ultrasonic image of the distal tip.

5. The method of claim 1 wherein the catheter shaft has at least a section with an outer jacket layer having a thickness of a quarter or three quarter wavelength of the ultrasound waves emitted by the ultrasound imaging system, the outer jacket comprising a polymeric material with an acoustic impedance which is between an acoustic impedance of blood and an acoustic impedance of the adjacent layer of the section of the shaft underlying the outer jacket layer, such that it more closely matches the acoustic impedance of blood than does an adjacent layer of the section of the shaft underlying the outer jacket layer, so that directing sonic energy at the catheter produces a reflected wave ultrasonic signal of the catheter which is less than the signal produced by the catheter without the outer jacket layer.

6. The method of claim 1 including filling the needle lumen of the shaft with an aqueous fluid, so that the catheter has a plastic-aqueous fluid interface which reflects less of the sonic energy than a plastic-air interface, and the ultrasonic image is produced with the aqueous fluid within the needle lumen of the shaft.

7. The method of claim 1 wherein the shaft has one or more lumens in addition to the needle lumen of the shaft, and including filling the one or more lumens with an aqueous fluid, so that the catheter has a plastic-aqueous fluid interface which reflects less of the sonic energy than a plastic-air interface, and the ultrasonic image is produced with the aqueous fluid within the additional one or more lumens.

8. The method of claim 1 further comprising determining a location of the catheter within the patient.

9. An echogenic needle catheter, comprising:

a) an elongated shaft having a needle lumen in communication with a needle distal port near a distal end of the elongated shaft, and a plurality of rotational orientation echogenic portions on an outer surface of the elongated shaft, formed of a material which is more highly echogenic than a material of the elongated shaft adjacent to the portions, the rotational orientation echogenic portions being arranged in an array in which each adjacent pair of portions are circumferentially and longitudinally spaced apart from one another; and

b) a needle in the needle lumen, which extends distally from the needle distal port in an extended configuration.

10. The needle catheter of claim 9 wherein all the rotational orientation echogenic portions have the same size and shape and material composition.

11. The needle catheter of claim 9 wherein the array is proximally adjacent to the distal port.

12. The needle catheter of claim 9 wherein the array comprises raised spherical sections extending out from the shaft outer surface.

13. The needle catheter of claim 9 wherein the needle has a retracted configuration in which a distal end of the needle is within the needle lumen.

14. A method of performing a medical procedure, comprising:

a) advancing within a patient'"'"'s body lumen an echogenic needle catheter, comprising

i) an elongated shaft having a needle lumen in communication with a needle distal port proximal to a distal end of the shaft, and a plurality of rotational orientation echogenic portions on an outer surface of a section of the shaft located adjacent to needle distal port, formed of a material which is more highly echogenic than a material of the shaft adjacent to the portions, the rotational orientation echogenic portions being arranged in an array in which each adjacent pair of portions are circumferentially and longitudinally spaced apart from one another; and

ii) a needle in the needle lumen, configured for slidably extending through the needle distal port in an extended configuration; and

b) determining the orientation of the needle distal port relative to a desired location in the body lumen by directing ultrasonic energy at the shaft section from an ultrasonic imaging device to produce an ultrasonic image of the shaft section in which the rotational orientation echogenic portions do not appear with an equal brightness.

15. The method of claim 14 including positioning the needle distal port at the desired location by rotating the catheter, and viewing a change in the brightness of the ultrasonic image of the echogenic rotational orientation portions produced by the rotated catheter.

16. The method of claim 14 wherein the determining of the orientation includes determining a location of the catheter within the patient.

17. An echogenic medical device, comprising:

an elongated shaft having a plurality of rotational orientation echogenic portions on an outer surface of the elongated shaft, formed of a material which is more highly echogenic than a material of the elongated shaft adjacent to the portions, the rotational orientation echogenic portions being arranged in an array in which each adjacent pair of portions are circumferentially and longitudinally spaced apart from one another.

18. The medical device of claim 17 wherein all the rotational orientation echogenic portions have the same size and shape and material composition, and wherein a distal end of the medical device includes a treatment device which is coupled to a lumen in the elongated shaft.

19. The medical device of claim 17 wherein the array is proximally adjacent to a distal end of the medical device.