WO2019108725A1

WO2019108725A1 - Needle assembly with shielded ultrasound transducer wire

Info

Publication number: WO2019108725A1
Application number: PCT/US2018/062952
Authority: WO
Inventors: Steve S. Khalaj; Shirzad SHAHRIARI
Original assignee: Avent, Inc.
Priority date: 2017-11-29
Filing date: 2018-11-29
Publication date: 2019-06-06

Abstract

A needle assembly for locating an object of interest (e.g., an anatomical region such as a muscle, nerve bundle, etc.) is provided. The needle assembly includes a needle having a needle body defining a proximal end and a distal end, wherein the distal end defines a tip, wherein the tip of the needle is inserted into a body of a mammal; a transducer located at the distal end of the needle; one or more transducer wires extending from a proximal end of the transducer towards the proximal end of the needle; and a length of tubing surrounding the needle, the transducer, and the one or more transducer wires, wherein the length of tubing has a proximal portion and a distal portion, wherein the proximal portion surrounds the one or more transducer wires and the distal portion surrounds the transducer, wherein the proximal portion includes a conductive filler.

Description

NEEDLE ASSEMBLY WITH SHIELDED ULTRASOUND TRANSDUCER WIRE

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims benefit of United States Provisional

Application Serial No. 62/592,030, having a filing date of November 29, 2017, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to medical devices used in

conjunction with ultrasound imaging systems, and more particularly to devices used in medical procedures such as nerve blocks, biopsies, or any other procedure where access is provide via a needle.

BACKGROUND OF THE INVENTION

Detection of anatomical objects using medical imaging is an essential step for many medical procedures, such as regional anesthesia nerve blocks, and is becoming the standard in clinical practice to support diagnosis, patient stratification, therapy planning, intervention, and/or follow-up. Various systems based on traditional approaches exist for anatomical detection and tracking during medical procedures, such as computed tomography (CT), magnetic resonance (MR), ultrasound, and fluoroscopic imaging systems.

For example, ultrasound imaging systems utilize sound waves with

frequencies higher than the upper audible limit of human hearing. Further, ultrasound imaging systems are widely used in medicine to perform both diagnosis and therapeutic procedures. In such procedures, sonographers perform scans of a patient using a hand-held probe or transducer that is placed directly on and moved over the patient.

One problem during procedures that utilize ultrasound imaging, such as regional anesthesia nerve block procedures or biopsy procedures, is the accurate placement of the needle in order to deliver the nerve block (e.g., via the delivery of an anesthetic through the needle, via the insertion of a catheter to deliver the nerve block via RF energy, or via the combination of the delivery of an anesthetic and RF energy) to the desired nerve bundle or to biopsy the correct tissue sample. Thus, the placement of an ultrasonic transducer at the tip of the needle can be used in conjunction with an ultrasound imaging system to visualize the location of the tip of the needle to assist a medical professional in accurately positioning the tip of the needle. However, the ultrasonic transducer at the tip of the needle is typically connected to an external power supply via a large coaxial cable in order to minimize the signal noise associated with the electrical connection between the ultrasonic transducer and the external power supply. While minimizing the signal noise is important, the size of the typical coaxial cable required to sufficiently minimize the signal noise can be problematic when it is desired to advance the needle to a nerve bundle or tissue. For instance, the increased diameter of the needle assembly due to the presence of a large coaxial cable can make it difficult for the needle assembly to reach a target nerve bundle or tissue located beneath several layers of skin, muscle, etc.

As such, a need exists for a means of electrically connecting an ultrasonic transducer at a tip of a needle to an external power supply where the connection has a reduced size while still effectively minimizing the signal noise through the wire.

SUMMARY

Objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention. The invention will be described in greater detail below by reference to embodiments thereof illustrated in the figures.

According to one embodiment of the present invention, a needle assembly for locating an object of interest (e.g., an anatomical region such as a muscle, nerve bundle, etc.) is provided. The needle assembly includes a needle having a needle body defining a proximal end and a distal end, wherein the distal end defines a tip, wherein the tip of the needle is inserted into a body of a mammal; a transducer located at the distal end of the needle; one or more transducer wires extending from a proximal end of the transducer towards the proximal end of the needle; and a length of tubing surrounding the needle, the transducer, and the one or more transducer wires, wherein the length of tubing has a proximal portion and a distal portion, wherein the proximal portion surrounds the one or more transducer wires and the distal portion surrounds the transducer.

In one particular embodiment, the transducer can be disposed on an outer surface of the needle. Further, the length of tubing can hold the transducer in place against the outer surface of the needle. In another embodiment, the length of tubing can include

polytetrafluoroethylene, polyethylene, polyurethane, silicone, or a combination thereof.

In still another embodiment, the length of tubing can be shrinkable. For instance, the length of tubing can be heat shrinkable.

In yet another embodiment, the length of tubing can have an outer diameter ranging from about 0.41 millimeters to about 1.301 millimeters.

In an additional embodiment, the length of tubing can have a wall thickness ranging from about 10 micrometers to about 101 micrometers.

In another embodiment, the proximal portion of the tubing can include a conductive filler.

In one more embodiment, the conductive filler can include a metal, a conductive polymer, carbon, or a combination thereof. For example, in some embodiments, the conductive filler can include nickel, copper, silver, gold, platinum, or a combination thereof. In other embodiments, the conductive filler can include polypyrrole, poly(3,4-ethylenedioxythiophene), polythiophene, polyaniline, poly-p- phenylene-sulphide, polyacetylene, polyisoprene, polybutadiene, or a combination thereof.

In one particular embodiment, the conductive filler can be present in the proximal portion of the length of tubing in an amount ranging from about 0.05 wt.% to about 10 wt.% based on the total weight of the proximal portion of the length of tubing.

In one embodiment, a human tissue impedance matching material can be disposed between the transducer and the distal portion of the tubing.

In another embodiment, the one or more transducer wires can be non- coaxial.

In still another embodiment, the one or more transducer wires can have a diameter ranging from about 15 micrometers to about 300 micrometers.

In yet another embodiment, the one or more transducer wires can include nickel, copper, silver, gold, platinum, or a combination thereof.

In an additional embodiment, the tip of the needle can be exposed and free of the length of tubing.

In one more embodiment, the tip of the needle can include an opening for delivery of an anesthetic nerve block. In one particular embodiment, the tip of the needle can facilitate delivery of a radiofrequency energy nerve block.

In still another embodiment, the transducer can be electrically connected to an external power supply via the one or more transducer wires.

In yet another embodiment, the transducer can transmit and receive signals for detection by an ultrasound imaging system, wherein the transducer enhances the visibility of the distal end of the needle on an ultrasound image.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention to one skilled in the art, including the best mode thereof, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:

Fig. 1 is a perspective view of one embodiment of the needle assembly of the present invention when used in conjunction with an ultrasound imaging system;

Fig. 2 illustrates a block diagram one of embodiment of a controller of an ultrasound imaging system with which the needle assembly of the present invention is used;

Fig. 3 illustrates one embodiment of the needle assembly of the present invention;

Fig. 4 is illustrates a side view of a portion of the needle assembly of Fig. 3 including the needle, transducer, one or more transducer wires, and length of tubing which shields the one or more transducer wires connecting the transducer to a power supply from signal noise;

Fig. 5 illustrates one embodiment of the needle assembly of the present invention; and

Fig. 6 illustrates a side view of a portion of the needle assembly of Fig. 5 including the needle, transducer, one or more transducer wires, and length of tubing which shields the one or more transducer wires connecting the transducer to a power supply from signal noise. Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the figures. Each embodiment is provided by way of explanation of the invention and is not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment may be used with another embodiment to yield still a further

embodiment. It is intended that the present invention include these and other modifications and variations coming within the scope and spirit of the invention.

Generally speaking, the present invention is directed to a needle assembly for locating an object of interest (e.g., an anatomical region such as a muscle, nerve bundle, etc.). The needle assembly includes a needle having a needle body defining a proximal end and a distal end, wherein the distal end defines a tip, wherein the tip of the needle is inserted into a body of a mammal; a transducer located at the distal end of the needle; one more transducer wires extending from a proximal end of the transducer towards the proximal end of the needle; and a length of tubing surrounding the needle, the transducer, and the one or more transducer wires. The length of tubing has a proximal portion and a distal portion, where the proximal portion surrounds the one or more transducer wires and the distal portion surrounds the transducer, wherein the proximal portion includes a conductive filler.

Referring now to the drawings, FIGS. 1 and 2 illustrate a medical imaging system 200 (e.g., an ultrasound imaging system) for use in conjunction with the needle assembly 100 of the present invention for scanning, identifying, and navigating toward anatomical objects 152 of a patient 210 (e.g., a mammal) according to the present invention. As used herein, the anatomical object 152 and surrounding tissue described herein may include any anatomical structure(s) and/or surrounding tissue(s) of a patient 210. For example, in one embodiment, the anatomical object(s) 152 may be a nerve bundle, a muscle, or any other anatomical object that can be visualized in a medical procedure (e.g., nerve block, biopsy, medicament delivery, etc.) performed by a medical professional 212. More specifically, as shown, the medical imaging system 200 may correspond to an ultrasound imaging system or any other suitable imaging system that can benefit from the present technology. Thus, the medical imaging system 200 may generally include a controller 216 having one or more processor(s) 218 and associated memory device(s) 220 configured to perform a variety of computer-implemented functions (e.g., performing the methods and the like and storing relevant data as disclosed herein), as well as a user display 206 configured to display an image 214 of an anatomical object 152 to an operator or medical professional 212. In addition, the medical imaging system 200 may include a user interface 204, such as a computer and/or keyboard, configured to assist the medical professional 212 in generating and/or manipulating the user display 206.

Additionally, as shown in FIG. 2, the controller 216 may also include a communications module 222 to facilitate communications between the processor(s) 218 and the various components of the medical imaging system 200 (e.g., any of the components of FIG. 1 ). Further, the communications module 222 may include a sensor interface 224 (e.g., one or more analog-to-digital converters) to permit signals transmitted from one or more probes (e.g., the ultrasound imaging probe 202, the needle assembly 100, or both) to be converted into signals that can be understood and processed by the processor(s) 218. It should be appreciated that the ultrasound imaging probe 202, the needle assembly 100, or both may be communicatively coupled to the communications module 222 using any suitable means. For example, as shown in FIG. 2, the ultrasound imaging probe 202 may be coupled to the sensor interface 224 via a wired connection 208. Flowever, in other embodiments, the ultrasound imaging probe 202 and/or the needle assembly 100 may be coupled to the sensor interface 224 via a wireless connection, such as by using any suitable wireless communications protocol known in the art. For example, as shown in FIG. 2, the needle assembly 100 may be coupled to the sensor interface 224 wirelessly. As such, the processor(s) 218 may be configured to receive one or more signals from ultrasound imaging probe 202 and/or the needle assembly 100.

As used herein, the term“processor” refers not only to integrated circuits referred to in the art as being included in a computer, but also refers to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, a field-programmable gate array (FPGA), and other programmable circuits. The processor(s) 218 is also configured to compute advanced control algorithms and communicate to a variety of Ethernet or serial- based protocols (Modbus, OPC, CAN, etc.). Furthermore, in certain embodiments, the processor(s) 218 may communicate with a server through the Internet for cloud computing in order to reduce the computation time and burden on the local device. Additionally, the memory device(s) 220 may generally comprise memory element(s) including, but not limited to, computer readable medium (e.g., random access memory (RAM)), computer readable non-volatile medium (e.g., a flash memory), a floppy disk, a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disc (DVD) and/or other suitable memory elements. Such memory device(s) 220 may generally be configured to store suitable computer- readable instructions that, when implemented by the processor(s) 218, configure the processor(s) 218 to perform the various functions as described herein.

Referring now to FIGs. 1 and 3-6, various embodiments of a needle assembly 100 that may be visualized via the medical imaging system 200 are illustrated. More specifically, as shown, the needle assembly 100 can include a needle 118 having a body 128 having an outer diameter 124 ranging from about 0.4 millimeters to about 1.2 millimeters and defined by a distal end 120 and a proximal end 122. A transducer 102 (e.g., an ultrasound transducer) can be disposed on an outer surface 146 of the needle 118. Further, the distal end 120 of the needle 118 can have a tip 126 that can be used for the delivery of RF energy or any other energy suitable for creating a nerve block, such as for the treatment of pain. In addition or alternatively, the tip 126 can include an opening 144 for delivery of a fluid and/or medicament, such as for delivery of an anesthetic nerve block, or can include a cutting tool (not shown) for taking a biopsy a tissue sample. Further, a handle 130 can be coupled to the proximal end 122 of the needle to assist the medical professional 212 in accurately positioning the needle within the patient 210. As shown in FIGs. 1 and 3, the handle 130 can be connected via an electrical connection 132 to a power supply 134. The power supply 134 can provide energy to the transducer 102 at the tip 126 of the needle. Further, the transducer 102 can enhance the visualization of the needle assembly 100 (e.g., the distal end 120 of the needle 118) when used in conjunction with the medical imaging system 200. The transducer 102 can be any piezoelectric element that can transmit ultrasound signals as known in the art. In one particular embodiment, the transducer can be a ceramic piezoelectric transducer. In another embodiment, the transducer can be a capacitive micromachined ultrasonic transducer. It is also to be understood that in addition to transmitting ultrasound signals, the transducer 102 can also receive ultrasound signals, such as from the medical imaging system 100. As shown, the transducer 102 can have a distal end 138 and a proximal end 140, where one or more transducer wires 104, which can connect the transducer 102 to a power supply and which can be used for transmitting and receiving signals, extends from the proximal end 140 of the transducer 102 towards the proximal end 122 of the needle 118 in order to connect the transducer 102 to the power supply 134. The one or more transducer wires 104, which can extend along the outer surface 146 of the needle 118, can be formed from any conductive material such as nickel, copper, silver, gold, platinum, or a combination thereof. Further, the one or more transducer wires 104 of the present invention can be non-coaxial in order to decrease the size of the needle assembly 100, which enables the use of the needle assembly 100 of the present invention in medical procedures requiring the needle assembly 100 to have a reduced footprint or diameter. For instance, the one or more transducer wires 104 can have a diameter 148 ranging from about 15 micrometers to about 300 micrometers, such as from about 20 micrometers to about 275 micrometers, such as from about 25 micrometers to about 250 micrometers. The ability of the needle assembly 100 of the present invention to use one or more transducer wires 104 having such a reduced diameter compared to conventional transducer wires where a larger, more cumbersome coaxial cable is required to shield the one or more transducer wires from electrical signal noise is facilitated by the use of a length of tubing 106 surrounding the needle 118 and the transducer 102, as discussed in more detail below.

Referring particularly to FIGs. 3-4, the needle assembly 100 including the needle 118, the transducer 102, and the one or more transducer wires 104 can also include a length of tubing 106 that surrounds the needle 118, the transducer 102, and the one or more transducer wires 104, which can be non-coaxial as discussed above. Specifically, the length of tubing 106 can include a distal portion 110 and a proximal portion 112. The distal portion 110 can extend along the body 128 towards the tip 126 of the needle 118 such that the tip 126 of the needle 118 is exposed and free of the length of tubing 106. As shown, the length of tubing 106 can hold the transducer 102 and one or more transducer wires 104 in place against an outer surface 146 of the needle 118. As such, the length of tubing 106 can have an inner diameter 114 ranging from about 0.4 millimeters to about 1.2 millimeters; and an outer diameter 116 ranging from about 0.41 millimeters to about 1.301 millimeters, such as from about 0.415 millimeters to about 1.291 millimeters, such as from about 0.42 millimeters to about 1.281 millimeters. Thus, the length of tubing 106 can have a wall thickness 150 ranging from about 10 micrometers to about 101 micrometers, such as from about 15 micrometers to about 91 micrometers, such as from about 20 micrometers to about 81 micrometers. The proximal portion 112 of the length of tubing 106 can surround the one or more transducer wires 104 and the distal portion 110 of the length of tubing 106 can surround the transducer 102. Further, the proximal portion 112 of the length of tubing 106 can include a conductive filler 108 (e.g., conductive particles, powder, flakes, etc.) that help shield the one or more transducer wires 104 from electrical signal noise that may hinder the effectiveness of the transducer 102 in enhancing the visibility of the distal end 120 of the needle 118. Meanwhile, the distal portion 110 of the length of tubing 106 which surrounds the transducer 102 is free of the conductive filler 108 so as to not distort the signals that may be transmitted and received by the transducer 102, such as when used the medical imaging system 100 to visualize the distal end 120 of the needle 118.

The length of tubing 106 can include any suitable material that is utilized in medical tubing, such as polytetrafluoroethylene, polyethylene, polyurethane, silicone, or a combination thereof. Further, the length of tubing 106 can be shrinkable, where the length of tubing can secure the transducer 102 and the one or more transducer wires 104 against the outer surface 146 of the needle 118 when the length of tubing 106 is shrunk around the body 128 of the needle 118. In one particular embodiment, the length of tubing 106 can be heat shrinkable. In addition, any suitable conductive filler 108 can be used, such as a metal, a conductive polymer, carbon, or a combination thereof. For instance, the conductive filler 108 can include nickel, copper, silver, gold, platinum, or a combination thereof. In other embodiments, the conductive filler 108 can include polypyrrole, poly(3,4- ethylenedioxythiophene), polythiophene, polyaniline, poly-p-phenylene-sulphide, polyacetylene, polyisoprene, polybutadiene, or a combination thereof. Moreover, regardless of the particular conductive filler 108 utilized, the conductive filler 108 can be present in the proximal portion 112 of the length of tubing 106 in an amount ranging from about 0.05 wt.% to about 10 wt.%, such as from about 0.1 wt.% to about 7.5 wt.%, such as from about 0.5 wt.% to about 5 wt.% based on the total weight of the proximal portion 112 of the length of tubing 106.

Referring now to FIG. 3, the needle assembly 100 as described above can also include an injection port 136 coupled to the handle 130 whereby fluid or medicament can be injected into a proximal end 122 of the needle 118. In addition, the needle assembly 100 can also include a catheter insertion port 142 located at the handle 130 whereby a catheter (not shown) can be inserted into the needle 118 as needed depending on the medical procedure being visualized.

In another embodiment, and referring specifically to FIGs. 5-6, the needle assembly 100 including the needle 118, the transducer 102, and the one or more transducer wires 104 can include a length of tubing 106 that surrounds the needle 118, the transducer 102, and the one or more transducer wires 104, which can be non-coaxial as discussed above. Specifically, the length of tubing 106 can include a distal portion 110 and a proximal portion 112. The distal portion 110 can extend along the body 128 towards the tip 126 of the needle 118 such that the tip 126 of the needle 118 is exposed and free of the length of tubing 106. As shown, the length of tubing 106 can hold the transducer 102 and one or more transducer wires 104 in place against an outer surface 146 of the needle 118. As such, the length of tubing 106 can have an inner diameter 114 ranging from about 0.4 millimeters to about 1.2 millimeters; and an outer diameter 116 ranging from about 0.41 millimeters to about 1.301 millimeters, such as from about 0.415 millimeters to about 1.291 millimeters, such as from about 0.42 millimeters to about 1.281 millimeters. Thus, the length of tubing 106 can have a wall thickness 150 ranging from about 10 micrometers to about 101 micrometers, such as from about 15 micrometers to about 91

micrometers, such as from about 20 micrometers to about 81 micrometers. The proximal portion 112 of the length of tubing 106 can surround the one or more transducer wires 104 and the distal portion 110 of the length of tubing 106 can surround the transducer 102. Further, as shown in FIGs. 5-6, it is to be understood that like the distal portion 110, the proximal portion 112 of the length of tubing 106 can be free of the conductive filler 108 described above with respect to FIGs. 3-4 so as to not distort the signals that may be transmitted and received by the transducer 102, such as when used the medical imaging system 100 to visualize the distal end 120 of the needle 118. The length of tubing 106 can include any suitable material that is utilized in medical tubing, such as polytetrafluoroethylene, polyethylene, polyurethane, silicone, or a combination thereof. Further, the length of tubing 106 can be shrinkable, where the length of tubing can secure the transducer 102 and the one or more transducer wires 104 against the outer surface 146 of the needle 118 when the length of tubing 106 is shrunk around the body 128 of the needle 118. In one particular embodiment, the length of tubing 106 can be heat shrinkable.

Referring now to FIG. 5, the needle assembly 100 as described above can also include an injection port 136 coupled to the handle 130 whereby fluid or medicament can be injected into a proximal end 122 of the needle 118. In addition, the needle assembly 100 can also include a catheter insertion port 142 located at the handle 130 whereby a catheter (not shown) can be inserted into the needle 118 as needed depending on the medical procedure being visualized.

Turning to FIGs. 3-6, although not required, in some embodiments, the needle assembly 100 can include an impedance matching material 152 disposed between the transducer 102 and the distal portion 110 of the tubing 106. The impedance matching material 152 can eliminate any air between the transducer 102 and the distal portion 110 of the tubing 106, where air could attenuate or otherwise negatively impact the signals being transmitted and received by the transducer 102 via the one or more transducer wires 104. In addition, the impedance matching material 152 can have an acoustic impedance that is similar to the impedance of human tissue (e.g., skin), such as an acoustic impedance that is +/- 20%, such as +/- 15%, such as +/- 10%, such as +/-5% of the impedance of human tissue. By having a similar acoustic impedance as human tissue, the impedance matching layer 152 can reduce the possibility of any reflection of the signals being transmitted and received by the transducer 102 via the one or more transducer wires 104. For instance, in one embodiment, the impedance matching layer can be silicone, polyimide, or any other polymer having an acoustic impedance similar to that of human tissue. In addition, the impedance matching material 152 can be applied to the needle assembly 100 by disposing, such as by coating, dabbing, painting, brushing, etc., a thin layer of the impedance matching material 152 on a surface of the transducer 102 and the distal end 120 of the needle 118 around which the tubing 106 will be disposed. Further, the impedance matching material 152 and the tubing 106 can be applied around the needle 118 in a vacuum chamber to ensure that any air is eliminated between the needle 118 and the tubing 106.

The present invention has been described both in general and in detail by way of examples. These and other modifications and variations of the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims.

Claims

WHAT IS CLAIMED IS:

1. A needle assembly for locating an anatomical region of interest, the needle assembly comprising:

a needle having a needle body defining a proximal end and a distal end, wherein the distal end defines a tip, wherein the tip of the needle is inserted into a body of a mammal;

a transducer located at the distal end of the needle;

one or more transducer wires extending from a proximal end of the transducer towards a proximal end of the needle; and

a length of tubing surrounding the needle, the transducer, and the one or more transducer wires, wherein the length of tubing has a proximal portion and a distal portion, wherein the proximal portion surrounds the one or more transducer wires and the distal portion surrounds the transducer.

2. The needle assembly of claim 1 , wherein the transducer is disposed on an outer surface of the needle.

3. The needle assembly of claim 2, wherein the length of tubing holds the transducer in place against the outer surface of the needle.

4. The needle assembly of any one of the foregoing claims, wherein the length of tubing comprises polytetrafluoroethylene, polyethylene, polyurethane, silicone, or a combination thereof.

5. The needle assembly of any one of the foregoing claims, wherein the length of tubing is shrinkable.

6. The needle assembly of claim 5, wherein the length of tubing is heat shrinkable.

7. The needle assembly of any one of the foregoing claims, wherein the length of tubing has an outer diameter ranging from about 0.41 millimeters to about 1.301 millimeters.

8. The needle assembly of any one of the foregoing claims, wherein the length of tubing has a wall thickness ranging from about 10 micrometers to about 101 micrometers.

9. The needle assembly of any one of the foregoing claims, wherein the proximal portion includes a conductive filler.

10. The needle assembly of claim 9, wherein the conductive filler comprises a metal, a conductive polymer, carbon, or a combination thereof.

11. The needle assembly of claim 10, wherein the conductive filler comprises nickel, copper, silver, gold, platinum, or a combination thereof.

12. The needle assembly of claim 10, wherein the conductive filler comprises polypyrrole, poly(3,4-ethylenedioxythiophene), polythiophene, polyaniline, poly-p- phenylene-sulphide, polyacetylene, polyisoprene, polybutadiene, or a combination thereof.

13. The needle assembly of any one of the foregoing claims, wherein the conductive filler is present in the proximal portion of the length of tubing in an amount ranging from about 0.05 wt.% to about 10 wt.% based on the total weight of the proximal portion of the length of tubing.

14. The needle assembly of any one of the foregoing claims, wherein the one or more transducer wires is non-coaxial.

15. The needle assembly of any one of the foregoing claims, wherein the one or more transducer wires has a diameter ranging from about 15 micrometers to about 300 micrometers.

16. The needle assembly of any one of the foregoing claims, wherein the one or more transducer wires comprises nickel, copper, silver, gold, platinum, or a combination thereof.

17. The needle assembly of any one of the foregoing claims, wherein a human tissue impedance matching material is disposed between the transducer and the distal portion of the tubing.

18. The needle assembly of any one of the foregoing claims, wherein the tip of the needle is exposed and free of the length of tubing.

19. The needle assembly of any one of the foregoing claims, wherein the tip of the needle includes an opening for delivery of an anesthetic nerve block.

20. The needle assembly of any one of the foregoing claims, wherein the tip of the needle facilitates delivery of a radiofrequency energy nerve block.

21. The needle assembly of any one of the foregoing claims, wherein the transducer is electrically connected to an external power supply via the one or more transducer wires.

22. The needle assembly of any one of the foregoing claims, wherein the transducer transmits and receives signals for detection by an ultrasound imaging system, wherein the transducer enhances the visibility of the distal end of the needle on an ultrasound image.