Echogenic Enhancement for a Needle
A needle includes a surface with a plurality of first ultrasound reflecting depressions formed therein. The first depressions are distributed along at least a portion of a length of the needle separated from one another by intervening sections. Each of the first depressions is extending along a curve between first and second ends adjacent to corresponding ones of the intervening sections with troughs at which surfaces of each of the first depressions most closely approach a longitudinal axis of the needle being offset toward the first ends of each of the first depressions.
This application claims the priority to the U.S. Provisional Application Ser. No. 61/141,473, entitled “Echogenic Enhancement for a Needle” filed on Dec. 30, 2008. The specification of the above-identified application is incorporated herewith by reference.
BACKGROUNDNeedle biopsies are common procedures for the diagnosis and staging of disease. These procedures are often done under ultrasound guidance to allow physicians performing the procedure to visualize the position of the needle in relation to target and surrounding tissue structures. Thus, the echogenicity of the needle (i.e., the visibility of the needle under ultrasound) often impacts the success of the procedure. The echogenecity may be affected by the size of the needle, a difference between the acoustic impedance of the needle and that of the surrounding tissue, an angle of the needle relative to the transducer, the frequency of the ultrasound energy used and various characteristics of the processing algorithm.
Various techniques have been developed in an attempt to improve the echogenic properties of needles including mechanical treatments of the outer surface of the needle or echogenic coatings. However, the current mechanical treatments involving the creation of discrete shapes repeated along the axis and/or about the circumference of a needle are complex to form. Other mechanical treatments include the formation of circumferential grooves or spirals around the needle. However, these grooves are tuned to only one angle and one frequency such that a slightly different spacing and/or a different frequency may have a significant negative impact on echogenic performance. The application of echogenic coatings increases the complexity of the devices and does not necessarily enhance the performance of these coated devices relative to the mechanical treatments described above. Furthermore, the echogenic properties of these coatings may decay over time.
SUMMARY OF THE INVENTIONThe present invention is directed to a needle comprising a surface with a plurality of first ultrasound reflecting depressions formed therein, the first depressions being distributed along at least a portion of a length of the needle separated from one another by intervening sections, each of the first depressions extending along a curve between first and second ends adjacent to corresponding ones of the intervening sections with troughs at which surfaces of each of the first depressions most closely approach a longitudinal axis of the needle being offset toward the first ends of each of the first depressions.
The present invention, which may be further understood with reference to the following description and the appended drawings, relates to devices for conducting biopsies under ultrasound guidance. Exemplary embodiments of the invention are directed to a pattern on an outer surface of a needle such that the needle has enhanced ultrasound visibility, allowing the needle to remain visible at various angles relative to the transducer. It will be understood by those of skill in the art that although the exemplary embodiments are described as a needle, the device may be any medical device that may be seen under ultrasound guidance. It will also be understood by those of skill in the art that since ultrasound is an electromagnetic energy, the patterns described herein, which enhance visibility, may also be used with other energy sources such as, for example, light.
As shown in
As would be understood by those skilled in the art, the needle 100 may be formed of any biocompatible material rigid enough to penetrate the tissue targeted by the procedure to which the needle 100 is directed. For example, the needle 100 may be formed of stainless steel or tungsten to enhance the echogencity of the needle. As would be understood by those skilled in the art, tungsten has an acoustic impedance greater than that of stainless steel increasing the difference in acoustic impedance between the needle 100 and the surrounding tissue and thereby enhancing echogenicity. It will be understood in the art, however, that any of a variety of materials may be used to form the needle 100 so long as the material is biocompatible and provides a visible difference in echogenicity as compared to the tissue through which it will be deployed.
The depressions 106, as shown in the enlarged side view of
In a preferred embodiment, each depression 106 extends around an entire circumference of the needle 100. However, it will be understood by those skilled in the art that the depression 106 may extend around only a portion of the circumference of the needle 100 or may be configured as a slot on the outer surface 104 of the needle 100. A space 108 which is substantially flat along a length of the needle 100 is located between each pair of adjacent depressions 106. In the embodiment shown in
It will be understood by those of skill in the art that the features of the needle 100, as described above may also be included in other medical devices that may be viewed under ultrasound guidance. For example, in another embodiment, a sheath, which may be slidable along a portion of a length of a needle may include a pattern substantially similar to the pattern formed by the depressions 106 on the needle 100. In another embodiment, a stylet, which may be slidable through a lumen of a needle to prevent non-target tissue from entering the lumen may be formed with a pattern substantially similar to the pattern formed by the depressions 106 on the needle 100.
A needle 200 according to another embodiment of the invention is substantially the same as the needle 100 described above except that the depressions 206 of the needle 200 are not all of the same shape. For example, the depressions 206 include a plurality of first depressions 206a each of which includes a steep portion 212 oriented to more effectively reflect energy back to a transducer oriented substantially parallel to the needle 200 from the steep portion 212 while each of a plurality of second depressions 206b is shaped as a shallow bowl 214 oriented to more effectively reflect energy to a transducer oriented at a steeper angle relative to the longitudinal axis of the needle 200 (at an angle close to 90° relative to the needle 200). In the embodiment of the needle 200 shown in
In a further embodiment of the present invention, as shown in
The embodiments of the present invention, as described above, may be easily manufactured using a simple tool. For example, the depressions 106 may be formed in the needle 100 using a tool with a protrusion a profile of which matches a desired shape of the depression 106. The tool may be rotated about a circumference, or a part of a circumference, of the needle 100 with the protrusion contacting the outer surface 104 to form the depressions 106 in the longitudinal body 118 the needle 100 as would be understood by those skilled in the art. Alternatively, instead of rotating the tool about the needle 100, the needle 100 may be rotated about a longitudinal axis of the needle while the tool remains stationary such that the protrusion contacts the outer surface 104 of the needle 100. The plurality of depressions 106 may be formed by simply moving the tool along the longitudinal axis of the needle 100 or by moving the needle 100 along the longitudinal axis, by a desired distance of the space 108, and rotating the tool or the needle 100 as described above. This may be repeated until a desired number of depressions 106 have been formed. Alternatively, a tool may include multiple protrusions to form the desired number of depressions 106 in one operation or in a reduced number of operations. For example, a tool to form a needle such as the needle 200 may include a first protrusion having a shape corresponding to the desired shape of the first depressions 206a while a second protrusion has a shape corresponding to a desired shape of the second depressions 206b, etc.
Alternatively, patterns formed by the depressions 106, 206, 306 may be applied to the needles 100, 200, 300, respectively, in the form of rings or other similar elements applied around at least a portion of the outer surfaces of the needles 100, 200 and 300. In another embodiment, a press may be used to stamp the needles with the depressions 106, 206, 306 to form the desired patterns on the needles 100, 200 and 300. In another embodiment, the depressions 106, 206 may be formed by laser micro-machining or by using an EDM process. However, it will be understood by those of skill in the art that any of a variety of methods may be used for forming any of the depressions 106, 206, 306 in the needles 100, 200, 300. As would be understood by those skilled in the art, once the depressions 306 have been formed by any of the above-described methods, the needle 300 may be coated with a desired thickness of the selected material to form the coating 306 using any known technique.
It will be apparent to those skilled in the art that various modifications and variations can be made in the structure and methodology of the present invention, without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided that they come within the scope of the appended claims and their equivalents.
Claims
1-16. (canceled)
17. A needle, comprising:
- a longitudinal body extending between a proximal end and a distal end and including a lumen extending therethrough, an outer surface of the longitudinal body including a plurality of first ultrasound reflecting depressions spaced apart from one another along at least a portion of a length of the longitudinal body, each of the first depressions extending along a longitudinal axis of the needle and including a concave curve having a trough, the concave curve having a first portion extending from the trough to a first end of the first depression at a first curvature slope and a second portion extending from the trough to a second end of the first depression at a second curvature slope, the first curvature slope being steeper than the second curvature slope.
18. The needle of claim 17, wherein the trough includes a gradual transition between the first and second curvature slopes.
19. The needle of claim 17, wherein the outer surface of the longitudinal body includes intervening sections between adjacent first depressions.
20. The needle of claim 19, wherein the intervening sections extend along and parallel to the longitudinal axis of the needle.
21. The needle of claim 20, wherein lengths of the intervening sections are one of consistent or varying along the needle.
22. The needle of claim 17, wherein the first portion approaches the first end of the first depression at an angle substantially perpendicular to the longitudinal axis of the needle.
23. The needle of claim 17, wherein the trough is offset towards the first end of the first depression.
24. The needle of claim 17, wherein the first end of the each fo the first depressions is at a distal end thereof.
25. The needle of claim 17, wherein each of the first depressions extends around an entire circumference of the needle.
26. The needle of claim 17, wherein each of the first depressions extends around only a portion of a circumference of the needle.
27. The needle of claim 17, further comprising a coating covering at least a portion of the needle, a material of the coating layer having an acoustic impedance selected to substantially match an acoustic impedance of bodily tissue within which the needle is to be used.
28. The needle of claim 27, wherein a speed of sound through the material of the coating layer is substantially less than that through the bodily tissue within which the needle is to be used.
29. The needle of claim 17, wherein the needle includes a lumen extending therethrough.
30. The needle of claim 17, further comprising a tip located at a distal end of the needle, the tip being formed angled relative to the longitudinal axis of the needle and adapted to receive therein bodily tissue penetrated by the needle.
31. A medical device, comprising:
- a longitudinal body extending between a proximal end and a distal end and including a lumen extending therethrough, an outer surface of the longitudinal body including a plurality of first ultrasound reflecting depressions spaced apart from one another along at least a portion of a length of the longitudinal body, each of the first depressions extending along a longitudinal axis of the device and including a concave curve having a trough, the concave curve having a first portion extending from the trough to a first end of the first depression at a first curvature slope and a second portion extending from the trough to a second end of the first depression at a second curvature slope, the first curvature slope being steeper than the second curvature slope.
Type: Application
Filed: Jan 14, 2019
Publication Date: May 16, 2019
Inventor: Shawn Ryan (Littleton, MA)
Application Number: 16/246,846