# US 12,766,292 B2 · Microcatheter device with non-linear bending stiffness

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- Number: US 12,766,292 B2
- Document ID: US12766292B2
- Status: Granted
- Kind: B2
- Application number: 17/901,821
- Filed: 2022-09-01
- Published: 2023-03-09
- Granted: 2026-10-20
- Earliest claimed: 2021-09-03
- Assignees: Scientia Vascular, LLC
- Applicants: Scientia Vascular, Inc.
- Inventors: Richard F. Maggio; Edward J. Snyder
- Web page: https://patentgrep.com/patent/US12766292B2

## CPC

- A61M 25/0054: {with regions for increasing flexibility}
- A61M 25/0023: {by the form of the lumen, e.g. cross-section, variable diameter}
- A61M 25/008: {Strength or flexibility characteristics of the catheter tip}
- A61M 2025/0042: {Microcatheters, cannula or the like having outside diameters around 1 mm or less}
- 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

Disclosed are microcatheter devices with features that provide effective axial response, good distribution of bending forces, and a smooth bending stiffness profile that minimizes abrupt changes in stiffness. A catheter device includes a microfabricated inner shaft having a plurality of gaps, and an outer member comprising a polymer material disposed within the gaps. The catheter device provides non-linear bending stiffness such that bending becomes more difficult as the bend angle increases.

## Claims

### Claim 1

A catheter device, comprising:
an inner shaft comprising a plurality of gaps formed therein; and
an outer member comprising a polymer material disposed within the gaps and comprising a transition section where a first polymer transitions to a second polymer of different hardness, wherein the outer shaft includes a change in bending stiffness at the transition section due to the transition from the first polymer to the second polymer, and
wherein the size and/or spacing of the plurality of gaps of the inner shaft at the transition section are configured such that the bending stiffness of the inner shaft at the transition section compensates for the change in bending stiffness of the outer member at the transition section.

### Claim 2 (depends on 1)

The catheter device of claim 1, wherein the inner shaft includes a plurality of axially extending beams that couple a plurality of circumferentially extending rings.

### Claim 3 (depends on 2)

The catheter device of claim 2, wherein the inner shaft includes one or both of a three-beam section and a two-beam section, wherein the three-beam section is disposed proximal of the two-beam section, and wherein at least a portion of the three-beam section has a higher bending stiffness than the two-beam section.

### Claim 4 (depends on 2)

The catheter device of claim 2, wherein the axially extending beams extend parallel to a longitudinal axis of the tube structure.

### Claim 5 (depends on 2)

The catheter device of claim 2, wherein the circumferentially extending rings form fully enclosed rings.

### Claim 6 (depends on 1)

The catheter device of claim 1, wherein the second polymer is proximal of the first polymer and has a greater hardness than the first polymer such that the outer member increases in bending stiffness across the transition section in the distal to proximal direction.

### Claim 7 (depends on 1)

The catheter device of claim 1, further comprising an inner liner around which the shaft is positioned.

### Claim 8 (depends on 7)

The catheter device of claim 7, wherein the polymer material of the outer member is fused to the liner, fills the gaps of the shaft, and covers outer surfaces of the shaft to encapsulate and embed the shaft.

### Claim 9 (depends on 1)

The catheter device of claim 1, wherein the shaft is formed from nitinol.

### Claim 10 (depends on 1)

The catheter device of claim 1, wherein the outer material comprises one or more polyether block amide polymers.

### Claim 11 (depends on 1)

The catheter device of claim 1, wherein the catheter device has a bending stiffness slope ((N·m2)/cm)) of no more than about 6.0×10−7 for a distal 15 cm section, no more than about 9.0×10−7 for a distal 35 cm section, and/or no more than about 9.0×10−7 for a distal 50 cm section.

### Claim 12 (depends on 1)

The catheter device of claim 1, wherein at least a portion of the distal 35 cm of the catheter device has a bending stiffness of 5×10−6 N·m2 or greater, and wherein the catheter device has a bending stiffness slope ((N·m2)/cm)) of no more than about 4.0×10−6 for a distal 35 cm section and/or no more than about 4.5×10−6 for a distal 50 cm section.

### Claim 13 (depends on 1)

The catheter device of claim 1, wherein: (1) at least a portion of the distal 35 cm of the catheter device has a bending stiffness of 5×10−6 N·m2 or greater; (2) the catheter device has a change in outer diameter of no more than 0.002 inches across the distal 15 cm and/or distal 35 cm section; and (3) the catheter device has a bending stiffness slope ((N·m2)/cm)) of no more than about 1.3×10−6 for a distal 15 cm section, no more than about 4.2×10−6 for a distal 35 cm section, and/or no more than about 1.1×10−5 for a distal 50 cm section.

### Claim 14 (depends on 1)

The catheter device of claim 1, further comprising a coil disposed distal of the shaft.

### Claim 15 (depends on 14)

The catheter device of claim 14, wherein the coil has a variable pitch.

### Claim 16

A catheter device, comprising:
a microfabricated inner shaft having a plurality of gaps formed therein,
wherein the inner shaft includes a plurality of axially extending beams that couple a plurality of circumferentially extending rings,
wherein the inner shaft includes a three-beam section and a two-beam section,
wherein the three-beam section is disposed proximal of the two-beam section, and
wherein at least a portion of the three-beam section has a higher bending stiffness than the two-beam section; and
an outer member comprising a polymer material disposed within the gaps,
wherein the outer member includes multiple different polymer durometers, and
wherein the outer member includes a transition section where a first polymer transitions to a second polymer of different hardness, wherein the outer member includes a change in bending stiffness at the transition section due to the transition from the first polymer to the second polymer,
wherein the size and/or spacing of the plurality of gaps of the inner shaft at the transition section are configured such that the bending stiffness of the inner shaft at the transition section compensates for the change in bending stiffness of the outer member at the transition section.

### Claim 17 (depends on 16)

The catheter device of claim 16, wherein the second polymer proximal of the first polymer and has a greater hardness than the first polymer such that the outer member increases in bending stiffness across the transition section in the distal to proximal direction, and wherein the shaft does not increase in bending stiffness across at least a portion of the transition section in the distal to proximal direction to compensate for the increase in bending stiffness of the outer member.

### Claim 18 (depends on 16)

The catheter device of claim 16, wherein the axially extending beams extend parallel to a longitudinal axis of the tube structure.

### Claim 19 (depends on 16)

The catheter device of claim 16, wherein the circumferentially extending rings form fully enclosed rings.