ECHOGENIC NEEDLE

Abstract

An echogenic needle may have at least one V-shaped spiral groove formed at its distal portion adjacent to its patient end. The walls of the groove are orthogonal to each other. The groove is titled at a given angle from a neutral position toward the proximal end of the needle so that when the needle is inserted into the patient at an insertion angle under ultrasound imaging, the ultrasound wave emitted from the ultrasound transducer is reflected in a substantially reverse direction back to the transducer by at least one wall of the spiral groove. A pair of crisscrossing grooves may be spirally wound about the distal portion of the needle with each groove being tilted to the given angle to enhance echogeneity. The echogeneity of the needle may also be enhanced by increasing the pitch density of each groove while maintaining the crisscrossing groves at their neutral position.

Claims

1. An echogenic needle including a shaft having a sharp distal tip and a proximal end with an outer circumferential surface made by the process of positioning a tool adapted to cut a groove having walls orthogonal to each other onto the outer circumferential surface of the needle so that walls having the same length would be formed onto the outer circumferential surface of the needle if the needle were to lie along a longitudinal axis relative to the tool at a neutral position, repositioning the needle and the tool relative to each other at an angle tilted away from the neutral position, and rotatably moving the tool and the shaft of the needle relative to each other to cut a spiral groove having a tilt angle relative to the neutral position onto the outer circumferential surface of at least one section of the needle.

2. The echogenic needle of claim 1, wherein the tilt angle is tilted toward the proximal end of the needle.

3. The echogenic needle of claim 1, wherein the tilt angle ranges from approximately 5° to 25°.

4. The echogenic needle of claim 1, wherein the tilt angle is preferably at 10°.

5. The echogenic needle of claim 1, wherein the needle has the spiral groove formed at multiple sections of the needle.

6. The echogenic needle of claim 1, wherein the spiral groove is formed in one direction along the at least one section of the needle; and wherein the needle is further processed by rotatably moving the tool and the shaft of the needle relative to each other to form another spiral groove having the tilt angle onto the outer circumferential surface of the needle in another direction along the at least one section such that the one spiral groove and the another spiral groove crisscross each other.

7. The echogenic needle of claim 1, wherein the spiral groove is formed to have a pitch of approximately 0.020 in (0.508 mm).

8. The echogenic needle of claim 1, wherein the spiral groove has a V-shape.

9. The echogenic needle of claim 1, wherein the spiral groove has a non-V shape.

10. The echogenic needle of claim 1, wherein the tool comprises a spinning wheel having an edge for forming the groove and the needle is rotatably moved along a longitudinal direction relative to the wheel to have the groove having the tilt angle cut onto the outer circumferential surface of the needle.

11. A method of making an echogenic needle including a shaft having a sharp distal tip and a proximal end with an outer circumferential surface, comprising the steps of: positioning relative to the needle a tool adapted to cut a groove having walls orthogonal to each other onto the outer circumferential surface of the needle so that walls having the same length would be formed onto the outer circumferential surface of the needle if the needle were to lie along a longitudinal axis relative to the tool at a neutral position; repositioning the needle and the tool relative to each other at an angle tilted away from the neutral position; and rotatably moving the tool and the shaft of the needle relative to each other to cut a spiral groove having a tilt angle relative to the neutral position onto the outer circumferential surface of at least one section of the needle.

12. The method of claim 11, further comprising the step of repositioning the angle to tilt toward the proximal end of the needle.

13. The method of claim 11, wherein the tilt angle is preferably at 10°.

14. The method of claim 11, further comprising the step of forming the spiral groove at multiple sections of the needle.

15. The method of claim 11, wherein the spiral groove is formed in one direction along the at least one section of the needle, the method further comprising the step of: rotatably moving the tool and the shaft of the needle relative to each other to form another spiral groove having the tilt angle onto the outer circumferential surface of the needle in another direction along the at least one section such that the one groove and the another groove crisscross each other.

16. The method of claim 11, further comprising the step of: forming the spiral groove having the tilt angle to have a pitch of approximately 0.020 in (0.508 mm).

17. An echogenic needle including a shaft having a sharp distal tip and a proximal end with an outer circumferential surface having at least one section thereon adapted to reflect ultrasonic waves directed thereat in a substantially reverse direction made by the process of: positioning relative to the needle a tool adapted to cut a groove having walls orthogonal to each other onto the outer circumferential surface of the needle so that walls having the same length would be formed onto the outer circumferential surface of the needle if the needle were to lie along a longitudinal axis relative to the tool at a neutral position, repositioning the needle and the tool relative to each other at an angle tilted away from the neutral position, and rotatably moving the tool and the shaft of the needle relative to each other to cut a spiral groove having a tilt angle relative to the neutral position onto the outer circumferential surface along the at least one section of the needle.

18. The echogenic needle of claim 17, wherein the tilt angle is tilted toward the proximal end of the needle from approximately 5° to 25°, and preferably at 10°.

19. The echogenic needle of claim 17, wherein the spiral groove is formed in one direction along the at least one section of the needle; and wherein the needle is further processed by rotatably moving the tool and the shaft of the needle relative to each other to form another spiral groove having the tilt angle onto the outer circumferential surface of the needle in another direction along the at least one section such that the one spiral groove and the another spiral groove crisscross each other.

20. The echogenic needle of claim 17, wherein the spiral groove is formed to have a pitch of approximately 0.020 in (0.508 mm).

Description

BRIEF DESCRIPTION OF THE FIGURES

[0011] The present invention will become apparent and the invention itself will be best understood with reference to the following description of the present invention taken in conjunction with the accompanying drawings, wherein:

[0012] FIG. 1 is an overall illustration of the exemplar embodiments of the needle of the instant invention;

[0013] FIG. 2 is an enlarged view of the distal portion of the needle of FIG. 1;

[0014] FIG. 3 is a cross-sectional view of a section of an exemplar groove of the needle of FIG. 1;

[0015] FIG. 4 is a cross-sectional view of the exemplar groove showing its neutral position and its “tilted” angle position;

[0016] FIG. 5A shows the patient end of the exemplar needle shown in FIG. 1;

[0017] FIG. 5B is an enlarged view of a portion of the exemplar needle of FIG. 5A showing crisscrossing spiral grooves;

[0018] FIG. 6A is a cross-sectional view of a distal or patient end of an exemplar inventive needle;

[0019] FIG. 6B is an enlarged view of a portion of the wall of the needle of FIG. 6A showing more clearly a number of cross sections of the groove;

[0020] FIG. 6C is an enlarged cross-sectional view showing the two walls of a V-shaped groove at its neutral position and its tilted position; and

[0021] FIG. 7 is an illustration showing an ultrasonic wave emitted from an ultrasonic transducer to the needle, and the reflection of the ultrasound wave back to the transducer by the groove at the neutral position and at the tilt angle position.

DETAILED DESCRIPTION OF THE INVENTION

[0022] An exemplar embodiment of the inventive needle used, for example for peripheral nerve block procedures, is shown in FIG. 1. As shown, needle 2 has a shaft 4 that extends along a longitudinal axis 6 having a distal or patient end 8 including a sharp bevel tip and a proximal end 10. For ease of illustration, the proximal end 10 of needle 2 has been truncated in FIG. 1. The section of the needle that is adjacent to patient end 8 is designated distal portion 12, although it should be appreciated that the demarcation of distal portion 12 as shown in FIG. 1 is for discussion only. Beyond distal portion 12 there are a number of markings 14 along the shaft of the needle to show the length, or the depth of the needle, as the needle is inserted into the subject, or patient. There are two sections 12a and 12b at the distal portion that are better illustrated in the enlarged distal portion view of the needle in FIG. 2.

[0023] As shown in FIG. 2, sections 12a and 12b each are formed with crisscrossing spiral grooves that are also shown in FIG. 5B. With reference to FIGS. 2, 5A and 5B, one spiral groove 16a is formed on the outer circumferential wall of needle shaft 4 in one direction, for example a clockwise direction, while an other spiral groove 16b crisscrosses groove 16a in an other direction, for example a counter-clockwise direction. For ease of reference, the respective grooves 16a and 16b spiral about the outer circumferential wall of needle shaft 4 may be referenced with respect to the sharp bevel tip at patient end 8 of the needle. Thus, for the discussion hereinbelow, groove 16a may be considered to be a spiral groove that is formed on the outer circumferential wall of needle shaft 4 in a clockwise direction relative to needle tip 8, while groove 16b spirally wounds about the outer circumferential wall of needle shaft 4 in a counter-clockwise direction relative to needle tip 8. The two spiral grooves crisscross each other in the manner as shown in FIGS. 2, 5A and 5B.

[0024] As best shown in FIG. 2, there is a non-groove section 18 that separates grooved sections 12a and 12b at the distal portion of the exemplar inventive needle. Although two grooved sections are shown in FIGS. 1 and 2, it should be appreciated that a plurality of more than two groove sections may also be formed along the needle away from its patient end.

[0025] The configuration of the groove of the needle is illustrated in FIGS. 3-4 and 6A-6C. FIG. 3 shows a cross-section of the needle, for example a portion of section 12a, with directional needle 20 referencing the proximal end of the needle and directional needle 22 referencing the patient end of the needle. As shown in FIG. 3, a number of cross-sections of a groove 16 are shown to have formed on the outer circumferential wall of needle shaft 4, which has a passage 4a extending therethrough along longitudinal axis 6. For the exemplar illustration of FIG. 3, a Θ angle is shown to be formed between the two walls of the groove, represented by lines 16w1 and 16w2 in FIG. 4. As the walls are orthogonal to each other, the Θ angle formed between the two walls is assumed to be approximately 90°. Thus, were the spiral groove at the outer surface of the circumferential wall of shaft 4 to be formed to have its walls orthogonal to each other relative to the longitudinal axis of the needle so that the walls have the same length, then each of the walls 16w1 and 16w2 would extend at approximately 45° relative to a plane along the longitudinal axis of shaft 4. This is shown by the dotted lines in FIGS. 4 and 6C, and may be referred to as the neutral position of the groove.

[0026] The inventors have found that, in use, a clinician usually positions a needle at an angle that facilitates the insertion of the needle into the subject. Thus, were the groove “tilted” at a given angle α toward the proximal end of the needle, an improved reflection of an ultrasound wave directed by an ultrasound transducer towards the needle may be obtained. By empirical studies, it was found that the α angle may range from approximately 5° to 25°, and preferably at 10° relative to the neutral position. Thus, instead of 45° for each of the walls of the V-shaped groove, the “tilted” groove would have its walls, as designed by lines 16w1′ and 16w2′, shifted together such that wall 16w1′ is at a β angle relative to the outside walls 4a of the needle shaft. Walls 16w1′ and 16w2′ remain orthogonal to each other when at the “tilted” position. For the exemplar embodiment where α=10°, β would be 35°. The depth of the groove may vary anywhere from 0.006 inch to 0.025 inch (0.1524 mm to 0.635 mm). It is further found that the pitch between grooves, as designated by reference number 24 in FIG. 6B, could be reduced to between 0.010 and 0.050 inch (0.254 mm to 1.27 mm), and preferably to approximately 0.020 inch (0.508 mm) to improve the pitch density of the needle and thereby its echogeneity. As should be appreciated, the pitch and groove as described above are not definitive for all needles but are instead meant to be utilized for needles that have conventionally dimensioned walls, for example a needle having a gauge anywhere between 16 to 24.

[0027] The configuration of the exemplar embodiment of the echogenic needle of the instant invention is further shown in FIGS. 6A-6C where a portion 12a1 of groove section 12a is enlarged in FIG. 6B to show an enlarged cross-sectional view of a number of V-shaped cross sections of the groove tilted toward the proximal end of the needle as described above. FIG. 6C shows the neutral position (in dotted lines) and the tilt angle position, or simply the tilted position (in solid lines) of the walls of an exemplar cross section of the V-shaped groove.

[0028] FIG. 7 is an exemplar illustration showing the difference in the reflection of the ultrasound wave emitted by an ultrasound transducer toward the exemplar inventive needle. For ease of discussion, the exemplar needle of FIG. 7 is assumed to have only one spiral groove. As shown, the transmitter of ultrasound transducer probe 26 emits an ultrasound wave 28 toward needle shaft 4, represented by line 4a, which is presumably being inserted into a subject. Thus, needle 4 is at an insertion angle Δ with reference to a plane 30 that is assumed to be in parallel to the plane at the output surface of transducer 26. From empirical studies, it was found that Δ in most instances is between 50° and 60°, and preferably at approximately 55°. Thus, it was determined that with the V-shaped groove at the tilt angle α, the ultrasound wave 28 is reflected as ultrasound wave 28a′ in a substantially reverse direction (approximately at 180°) back to transducer 26, presumably to its receiver. Thus, an improved reflection view of the exemplar inventive needle may be gleaned under ultrasound or radiographic imaging by tilting the groove at an angle α.

[0029] As discussed above, with the exemplar illustration as shown in FIG. 7, it was determined that if the spiral grooves were formed at their respective neutral positions, the ultrasound wave 28 would be reflected as a return ultrasound wave, represented by lines 28a, in a direction that angles away, or offset from ultrasound transducer 26. However, based on additional empirical studies, it has been determined that were the crisscrossing spiral grooves formed on a needle with their corresponding respective walls orthogonal to the longitudinal axis of the needle but with the pitch density for each of the spiral grooves increased more than as discussed above, an improved and acceptable reflective image of the echogenic portion(s) of the needle under ultrasound imaging is nonetheless achieved. In other words, spiral grooves formed in the neutral position relative to the longitudinal axis of the needle with a predetermined increased pitch density would provide an improved reflective image of the echogenic portion(s) of the needle, similar to the needle embodiment with the tilted grooves as discussed above.

[0030] The neutral positioned spiral grooves are represented by the dotted wall lines 16w1 and 16w2 in FIGS. 4 and 6C. Due to those spiral grooves being formed at the neutral position and orthogonal to each other, their walls, for example 16w1 and 16w2, have substantially the same length or height. The pitch, or the groove width, between the walls of each of the grooves, designated by 24 in FIG. 6, was determined to have a range approximately 0.001 inch to 0.003 inch (0.025 mm to 0.075 mm), and preferably at approximately 0.002 inch (0.053 mm). The desired groove depth was determined to have a range of approximately 0.0006 inch to 0.0010 inch (0.015 mm to 0.025 mm). As should be appreciated, the depth and pitch of the groove are interrelated as the change in the value of one may affect the change in the value of the other.

[0031] With the combination of clockwise and counter-clockwise spiral wound grooves, and with each of the grooves having a preferable pitch of approximately 0.020 inch (0.508 mm) for the tilted echogenic needle embodiment, an echogenic needle with improved echogeneity results. So, too, an improved echogenic needle adapted to provide improved echogeneity results may be achieved with non-tilted crisscrossing clockwise and counter-clockwise spiral grooves each having an increased pitch density or groove width having a range of 0.001 inch to 0.003 inch (0.025 mm to 0.075 mm), and preferably of approximately 0.0021 inch (0.053 mm). It should be appreciated that instead of a V-shaped groove, each of the grooves may be U-shaped or some other shape such as trapezoidal-shaped, so long as the walls of the groove are made to be substantially orthogonal to each other. Furthermore, one of the crisscrossing grooves may have a V-shape while the other groove may have a U-shape or some other shape including trapezoidal that clearly defines the orthogonal walls of the groove.

[0032] Although not disclosed above, it should be appreciated that the proximal end of the needle may be fixedly bonded or connected to a needle hub, so that the needle may be fluidly coupled to a medicament or fluid store, such as a syringe or a pump, to infuse medicament or fluid to the patient once the needle has been inserted into and appropriately positioned within the patient. The respective connectors of the needle hub and the fluid store may be configured to have complementary features or configurations that allow only those connectors to be coupled to each other, i.e., each of those connectors is not connectable to a counterpart conventional luer connector. Moreover, before use, the needle may be protected by a sleeve to prevent contamination and for shipping purposes. To prevent coring of the needle, a stylet may be concentrically fitted into the through passage of the needle when the needle is inserted into the patient, and removed thereafter.

[0033] The forming of the spiral grooves onto the outer circumferential wall of the needle shaft may be accomplished in substantially the same manner as is done for the above-noted Wallace Amniocentesis Needles. In the alternative, the spiral grooves may be formed substantially in accordance with the disclosure of JP2000051219, which was assigned to the assignee of the instant invention. In brief, the ‘219 publication discloses an edge of a spinning wheel is used to form a groove on a catheter that rotatably moves along a longitudinal direction relative to the wheel.

[0034] Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that the matter described throughout this specification and shown in the accompanying drawings be interpreted as illustrative only, and not in a limiting sense. Accordingly, it is intended that the invention be limited only by the sprit and scope of the hereto appended claims.