Non-magnetic stainless steel surgical needle
AssigneeEthicon, Inc.
InventorsTimothy Sardelis, William McJames
Life of this patent
Estimating the term…
Abstract
A non-magnetic surgical needle. The needle is made from Type 316 stainless steel or ERSTE 4456CA stainless steel and is work hardened to have mechanical properties substantially equivalent to a surgical needle made from conventional magnetic stainless steel. The needle is useful in the magnetic field of a magnetic resonance imaging diagnostic apparatus.
Claims4
A non-magnetic surgical needle comprising an elongated member having a distal piercing tip and a proximal suture mounting end, said needle comprising Type 316 stainless steel, wherein said needle is work-hardened and has the following mechanical characteristics:
- a modulus of elasticity (E) of at least 25.times.10.sup.6 pounds per square inch;
- an ultimate tensile strength of at least 250,000 pounds per square inch;
- a yield strength of at least 200,000 pounds per square inch;
- a bending strength of about 7.5.times.10.sup.-5 inch-pounds to about 8.8 inch-pounds;
- and,
- sufficient ductility to such that the needle can be effectively be bent from a resting shape through an arc of 90 degrees, and rebent in the reverse direction an additional 90 degrees back to the resting shape,
- wherein said needle is non-magnetic in the magnetic field of a 1.5 Telsa magnet.
A non-magnetic surgical needle comprising an elongated member having a distal piercing tip and a proximal suture mounting end, said needle comprising ERSTE Type 4456 CA stainless steel alloy, wherein said needle is work hardened and has the following mechanical characteristics:
- a modulus of elasticity (E) of at least 25.times.10.sup.6 pounds per square inch;
- an ultimate tensile strength of at least 250,000 pounds per square inch;
- a yield strength of at least 200,000 pounds per square inch;
- a bending strength of about 7.5.times.10.sup.-5 inch pounds to about 8.8 inch-pounds;
- and,
- sufficient ductility to such that the needle can be effectively be bent from a resting shape through an arc of 90 degrees, and rebent in the reverse direction an additional 90 degrees back to the resting shape,
- wherein said needle is non-magnetic in the magnetic field of a 1.5 Telsa magnet.
A method of suturing tissue in the magnetic field of an MRI diagnostic unit, said method comprising:
- passing a surgical needle and attached suture through tissue a sufficient number of times to effectively approximate the tissue, said surgical needle comprising:
- a non-magnetic surgical needle having an elongated member having a distal piercing tip and a proximal suture mounting end, said needle comprising Type 316 stainless steel, wherein said needle is work hardened and has the following mechanical characteristics:
- a modulus of elasticity (E) of at least 25.times.10.sup.6 pounds per square inch;
- an ultimate tensile strength of at least 250,000 pounds per square inch;
- a yield strength of at least 200,000 pounds per square inch;
- a bending strength of about 7.5.times.10.sup.-5 inch-pounds to about 8.8 inch-pounds;
- and,
- sufficient ductility to such that the needle can be effectively be bent from a resting shape through an arc of 90 degrees, and rebent in the reverse direction an additional 90 degrees back to the resting shape,
- wherein said needle is non-magnetic in the magnetic field of a 1.5 Telsa magnet.
A method of suturing tissue in the magnetic field of an MRI diagnostic unit, said method comprising:
- passing a surgical needle and attached suture through tissue a sufficient number of times to effectively approximate the tissue, said surgical needle comprising:
- a non-magnetic surgical needle having an elongated member having a distal piercing tip and a proximal suture mounting end, said needle comprising ERSTE 4456 CA stainless steel alloy, wherein said needle is work hardened and has the following mechanical characteristics:
- a modulus of elasticity (E) of at least 25.times.10.sup.6 pounds per square inch;
- an ultimate tensile strength of at least 250,000 pounds per square inch;
- a yield strength of at least 200,000 pounds per square inch;
- a bending strength of about 7.5.times.10.sup.-5 inch-pounds to about 8.8 inch-pounds;
- and,
- sufficient ductility to such that the needle can be effectively be bent from a resting shape through an arc of 90 degrees, and rebent in the reverse direction an additional 90 degrees back to the resting shape,
- wherein said needle is non-magnetic in the magnetic field of a 1.5 Telsa magnet.
Dependencies are inferred from the claim text.