# US 10,492,806 B2 · Medical guide wire

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- Number: US 10,492,806 B2
- Document ID: US10492806B2
- Status: Granted
- Kind: B2
- Application number: 15/717,950
- Filed: 2017-09-28
- Published: 2018-04-05
- Granted: 2019-12-03
- Earliest claimed: 2016-09-30
- Assignees: FMD Co., Ltd.
- Applicants: FMD Co., Ltd.
- Inventors: Tsuyoshi Terashi; Seiji Shimura
- Web page: https://patentgrep.com/patent/US10492806B2

## CPC

- A61B 17/22: Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for
- A61L 31/022: {Metals or alloys}
- A61L 31/10: Macromolecular materials
- A61M 25/09: Guide wires
- A61B 2017/00477: {Coupling (A61B2017/0046 takes precedence)}
- A61B 2017/00862: {elastic or resilient}
- A61B 2017/00867: {shape memory effect}
- A61B 2017/00942: {hydrophilic}
- A61B 2017/22038: {with a guide wire}
- A61M 2025/09075: {having a core without a coil possibly combined with a sheath}
- A61M 2025/09108: {Methods for making a guide wire}
- A61M 2025/09133: {having specific material compositions or coatings; Materials with specific mechanical behaviours, e.g. stiffness, strength to transmit torque}
- A61M 2025/0915: {having features for changing the stiffness}
- A61M 2025/09166: {having radio-opaque features}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}

## Abstract

In a medical guide wire having a connecting structure formed by three members: a tubular connector; a first core; and a second core, when a torsional rigidity of one member is lower than the torsional rigidity of the materials of both end portions, for example, the twist is unevenly generated between the members and the rotation transmission performance to the distal end side is significantly reduced. In such a case, there is a technical problem for improving the rotation transmission performance to the distal end side. In the connecting structure formed by three members, as a result of focusing on the torsional rigidity of the three members and considering the torsional rigidity ratios between the members, the technical problem for improving the rotation transmission performance to the distal end side can be solved when the torsional rigidity ratios satisfy a predetermined relation.

## Claims

### Claim 1

A medical guide wire comprising:
a first core;
a second core; and
a tubular connector, wherein
the first core has a pseudoelastic property and includes a small diameter proximal connection portion and a first core-large diameter proximal portion in order from the proximal end to the distal end,
the tubular connector has a pseudoelastic property,
the first core-large diameter proximal portion and the tubular connector are a Ni—Ti alloy having the transverse elastic modulus of between 17650 Mpa and 21575 Mpa when an austenite phase is exhibited,
the second core has a strain-induced martensitic transformation phase and includes a second core-large diameter portion and a small diameter distal connection portion in order from the proximal end to the distal end,
the second core-large diameter portion is an austenitic stainless steel wire having the transverse elastic modulus of 68500 Mpa or more,
the small diameter proximal connection portion has a first small diameter proximal portion and a second small diameter proximal portion in order from the distal end to the proximal end,
the outer diameter of the second small diameter proximal portion is gradually reduced from the outer diameter of the first small diameter proximal portion,
the small diameter distal connection portion has a first small diameter distal portion and a second small diameter distal portion in order from the proximal end to the distal end,
the outer diameter of the second small diameter distal portion is gradually reduced from the outer diameter of the first small diameter distal portion,
the small diameter proximal connection portion is arranged inside the tubular connector at the distal end of the tubular connector and the small diameter distal connection portion is arranged inside the tubular connector at the proximal end of the tubular connector,
the distal end of the tubular connector is in contact with a first step between the first core-large diameter proximal portion and the small diameter proximal connection portion, the first core-large diameter proximal portion having a larger outer diameter than the small diameter proximal connection portion,
the proximal end of the tubular connector is in contact with a second step between the second core-large diameter portion and the small diameter distal connection portion, the second core-large diameter portion having a larger outer diameter than the small diameter distal connection portion, and
when the torsional rigidity of the first core-large diameter proximal portion is defined as K1, the transverse elastic modulus of the first core-large diameter proximal portion is defined as G1, the outer diameter of a first contact position between the tubular connector and the first core-large diameter proximal portion is defined as D1, the torsional rigidity of the second core-large diameter portion is defined as K2, the transverse elastic modulus of the second core-large diameter portion is defined as G2, the outer diameter of a second contact position between the tubular connector and the second core-large diameter portion is defined as D2, the torsional rigidity of the tubular connector is defined as J1, the transverse elastic modulus of the tubular connector is defined as G3, the outer diameter of the tubular connector is defined as do, and the inner diameter of the tubular connector is defined as do1, the torsional rigidity ratio (K2/K1) of the torsional rigidity K2 of the second core-large diameter portion with respect to the torsional rigidity K1 of the first core-large diameter proximal portion satisfies the following relational expression:
K2/K1=G2×D24/(G1×D14),
the torsional rigidity ratio J1/K1 of the torsional rigidity J1 of the tubular connector with respect to the torsional rigidity K1 of the first core-large diameter proximal portion satisfies the following relational expression:
J1/K1=G3×(do4−do14)/(G1×D14), and
the torsional rigidity ratio (K2/K1) of the torsional rigidity K2 of the second core-large diameter portion with respect to the torsional rigidity K1 of the first core-large diameter proximal portion satisfies the relational expressions:
5.65≥(K2/K1)>(J1/K1)>1; and
4.48≥(J1/K1).

### Claim 2

A medical guide wire comprising:
a first core;
a second core; and
a tubular connector, wherein
the first core has a pseudoelastic property and includes a small diameter proximal connection portion and a first core-large diameter proximal portion in order from the proximal end to the distal end,
the tubular connector has a pseudoelastic property,
the small diameter proximal connection portion and the tubular connector are a Ni—Ti alloy having the transverse elastic modulus of between 17650 Mpa and 21575 Mpa when an austenite phase is exhibited,
the second core has a strain-induced martensitic transformation phase and includes a second core-large diameter portion and a small diameter distal connection portion in order from the proximal end to the distal end,
the small diameter distal connection portion is an austenitic stainless steel wire having the transverse elastic modulus of 68500 Mpa or more,
the tubular connector has a constant outer diameter over an entire length,
the small diameter proximal connection portion has a first small diameter proximal portion arranged inside the tubular connector at the distal end of the tubular connector,
the small diameter distal connection portion has a first small diameter distal portion arranged inside the tubular connector at the proximal end of the tubular connector,
the first small diameter proximal portion has a first tapered portion which is in contact with a first inner end portion of the distal end of the tubular connector,
the first small diameter distal portion has a second tapered portion which is in contact with a second inner end portion of the proximal end of the tubular connector,
when the torsional rigidity of the small diameter proximal connection portion is defined as k11, the transverse elastic modulus of the small diameter proximal connection portion is defined as G1, the outer diameter of a first contact position between the tubular connector and the small diameter proximal connection portion is defined as d13, the torsional rigidity of the small diameter distal connection portion is defined as k22, the transverse elastic modulus of the small diameter distal connection portion is defined as G2, the outer diameter of a second contact position between the tubular connector and the small diameter distal connection portion is defined as d23, the torsional rigidity of the tubular connector is defined as J1, the transverse elastic modulus of the tubular connector is defined as G3, the outer diameter of the tubular connector is defined as do, and the inner diameter of the tubular connector is defined as do1, the torsional rigidity ratio (k22/k11) of the torsional rigidity k22 of the small diameter distal connection portion with respect to the torsional rigidity k11 of the small diameter proximal connection portion satisfies the following relational expression:
k22/k11=G2×d234/(G1×d134),
the torsional rigidity ratio (J1/k11) of the torsional rigidity J1 of the tubular connector with respect to the torsional rigidity k11 of the small diameter proximal connection portion satisfies the following relational expression:
J1/k11=G3×(do4−do14)/(G1×d134), and
the torsional rigidity ratio (J1/k11) of the torsional rigidity J1 of the tubular connector with respect to the torsional rigidity k11 of the small diameter proximal connection portion and the torsional rigidity ratio (k22/k11) of the torsional rigidity k22 of the small diameter distal connection portion with respect to the torsional rigidity k11 of the small diameter proximal connection portion satisfy the following relational expressions:
4.85≥(k22/k11)>(J1/k11)>1; and
3.40≥(J1/k11).

### Claim 3 (depends on 2)

The medical guide wire according to claim 2, wherein
the torsional rigidity ratio (J1/k11) of the torsional rigidity J1 of the tubular connector with respect to the torsional rigidity k11 of the small diameter proximal connection portion and the torsional rigidity ratio (k22/k11) of the torsional rigidity k22 of the small diameter distal connection portion with respect to the torsional rigidity k11 of the small diameter proximal connection portion satisfy the following relational expressions:
4.50≥(k22/k11)>(J1/k11)>1; and
3.20≥(J1/k11)≥1.20.