Echogenic needle
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.
1 . A method of making an echogenic needle having a shaft that has a sharp distal tip, a proximal end and an outer circumferential surface, comprising:
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 were the needle 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 toward the proximal end of the needle with the walls remaining orthogonal to each other; 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 method of claim 1 , further comprising:
preferably positioning the tilt angle to be at 10° away from the neutral position.
3 . The method of claim 1 , further comprising:
forming the spiral groove at multiple sections of the needle.
4 . The method of claim 1 , further comprising:
forming the spiral groove in one direction along the at least one section of the needle; and
rotatably moving the tool and the shaft of the needle relative to each other to form another spiral groove having another tilt angle onto the outer circumferential surface of the needle in another direction along the at least one section such that the spiral groove formed along the one direction and the another spiral groove formed along the another direction crisscross each other.
5 . The method of claim 1 , further comprising:
forming the spiral groove having the tilt angle to have a pitch of approximately 0.020 in (0.508 mm).
6 . The method of claim 1 , further comprising:
varying the tilt angle from approximately 5° to 25°.
7 . The method of claim 6 , further comprising:
forming the spiral groove to have a V-shape.
8 . The method of claim 6 , further comprising:
forming the spiral groove to have a non-V shape.
9 . A method of making an echogenic needle having a shaft including 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, comprising:
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 toward the proximal end of the needle; 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 with the walls of the groove remaining orthogonal to each other.
10 . The method of claim 9 , further comprising:
tilting the angle toward the proximal end of the needle from approximately 5° to 25°.
11 . The method of claim 9 , further comprising:
preferably tilting the angle to be at 10°.
12 . The method of claim 9 , further comprising:
rotatably moving the tool in another direction relative to the shaft of the needle to form another spiral groove having another angle onto the outer circumferential surface of the needle along another direction different from the direction of the spiral groove such that the spiral groove and the another spiral groove crisscross each other at the at least one section of the needle.
13 . The method of claim 12 , further comprising:
forming crisscrossing spiral grooves at multiple sections of the needle.
14 . The method of claim 9 , further comprising:
forming the spiral groove to have a pitch of approximately 0.020 in (0.508 mm).