Deployable compliant mechanism

Patent metadata

Field	Value
Publication number	US-12036129-B2
Application number	US-202117445017-A
Country	US
Kind code	B2
Filing date	Aug 13, 2021
Priority date	Aug 13, 2020
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

Deployable Euler Spiral Connectors (DESCs) are introduced as compliant deployable flexures that can span gaps between segments in a mechanism and then lay flat when under strain in a stowed position. This paper presents models of Euler spiral beams combined in series and parallel that can be used to design compact compliant mechanisms. Constraints on the flexure parameters of DESCs are also presented. Analytic models developed for the force-deflection behavior and stress were compared to finite element analysis and experimental data. A spinal implant and a linear ratcheting system are presented as illustrative applications of DESCs.

First claim

What is claimed is:

1. An expandable implantable device, comprising:
a plurality of support members; and
a plurality of compliant connectors connecting adjacent support members of the plurality of support members,
wherein the plurality of support members includes a planar arrangement of longitudinal members that are movable relative to each other, between a stowed configuration for insertion of the expandable implantable device into an intervertebral implant location, and a deployed configuration for expansion of the expandable implantable device at the intervertebral implant location,
wherein, in the stowed configuration,
each of the plurality of support members abuts an adjacent support member of the plurality of support members, with central longitudinal axes of the plurality of support members aligned in a first direction, and
the plurality of compliant connectors are arranged in a planar configuration between the adjacent support members, with central longitudinal axes of each of the plurality of compliant connectors aligned in the first direction, between respective pairs of adjacent support members.

2. The expandable implantable device of claim 1 , wherein the plurality of compliant connectors maintains a relative position of the plurality of support members so as to maintain the expandable implantable device in the stowed configuration or the deployed configuration.

3. The expandable implantable device of claim 1 , wherein the stowed configuration is a fully stowed configuration in which each of the plurality of support members abuts at least one adjacent support member, such that a volume between adjacent support members of the plurality of support members is occupied by the plurality of compliant connectors.

4. The expandable implantable device of claim 3 , wherein the deployed configuration is a fully deployed configuration in which the plurality of compliant connectors are fully expanded to span spaces formed between the adjacent support members, wherein the fully deployed configuration corresponds to a maximum overall volume of the expandable implantable device.

5. The expandable implantable device of claim 4 , wherein the plurality of support members are movable to a plurality of intermediate configurations between the fully stowed configuration and the fully deployed configuration.

6. The expandable implantable device of claim 5 , wherein the plurality of support members are configured to move, between the stowed configuration and the deployed configuration, in response to an externally applied force.

7. The expandable implantable device of claim 5 , wherein the plurality of support members are configured to move, from the fully stowed configuration to an intermediate configuration of the plurality of intermediate configurations, in response to a release of strain energy stored by the plurality of compliant connectors.

8. The expandable implantable device of claim 7 , wherein the plurality of support members are configured to move from the intermediate configuration towards the fully deployed configuration in response to an externally applied force.

9. The expandable implantable device of claim 3 , wherein, in the fully stowed configuration, the volume between adjacent support members of the plurality of support members is substantially fully occupied by the plurality of compliant connectors between the adjacent support members, such that a distance between adjacent support members of the plurality of support members corresponds to a thickness of the plurality of compliant connectors extending between the adjacent support members, and the fully stowed configuration corresponds to a minimum overall volume of the expandable implantable device.

10. The expandable implantable device of claim 1 , wherein each of the plurality of compliant connectors is configured to store strain energy in the stowed configuration of the expandable implantable device, and wherein the plurality of compliant connectors are configured to expand and separate the plurality of support members in response to a release of the strain energy stored by the plurality of compliant connectors.

11. The expandable implantable device of claim 1 , wherein each of the plurality of compliant connectors has an Euler spiral shape.

12. The expandable implantable device of claim 1 , wherein the plurality of compliant connectors includes a plurality of Deployable Euler Spiral Connectors (DESCs).

13. The expandable implantable device of claim 1 , wherein, in the stowed configuration,
a first side portion of each of the plurality of compliant connectors contacts a corresponding side portion of a first support member of a pair of adjacent support members of the plurality of support members, and
a second side portion of each of the plurality of compliant connectors abuts a corresponding side portion of a second support member of the pair of adjacent support members of the plurality of support members.

14. The expandable implantable device of claim 13 , wherein, in the stowed configuration, the central longitudinal axes of the plurality of support members and the central longitudinal axes of the plurality of compliant connectors are arranged substantially in parallel.

15. The expandable implantable device of claim 1 , wherein the plurality of support members are configured to move in a second direction relative to each other to move from the stowed configuration to the deployed configuration, and to move in a third direction relative to each other to move from the deployed configuration to the stowed configuration, wherein the second direction is substantially orthogonal to the first direction, and the third direction is substantially opposite the second direction.

16. The expandable implantable device of claim 1 , wherein, in the stowed configuration, side portions of the plurality of compliant connectors contact a corresponding side portion of an adjacent support member of the plurality of support members.

17. The expandable implantable device of claim 1 , wherein the plurality of support members includes a planar arrangement of rigid longitudinal members, including:
a central support member; and
a plurality of auxiliary support members arranged symmetrically about the central support member.

18. The expandable implantable device of claim 1 , wherein the expandable implantable device is a spinal implant implantable at the intervertebral implant location between adjacent vertebrae of a spine of a patient, and wherein, in the deployed configuration, the plurality of support members of the expandable implantable device are configured to support the adjacent vertebrae of the spine and to maintain a relative position of the adjacent vertebrae.

19. The expandable implantable device of claim 18 , wherein, in the deployed configuration, a height and a degree of lordosis of the plurality of support members of the expandable implantable device are configured to maintain an anatomical alignment of the spine.

20. An expandable implantable device, comprising:
a plurality of support members; and
a plurality of compliant connectors connecting pairs of adjacent support members of the plurality of support members,
wherein the plurality of support members are movable relative to each other, between a stowed configuration for insertion of the expandable implantable device into an intervertebral implant location, and a deployed configuration for expansion of the expandable implantable device at the intervertebral implant location, and
wherein, in the stowed configurati

Assignees

• Brigham Young Univ Byu
• Univ Brigham Young

Inventors

• Howell Larry L
• Ynchausti Collin
• Bowden Anton E
• Brown Nathan

Classifications

• A61F2/30942

  for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques · CPC title

• A61F2002/30943

  using mathematical models · CPC title

• A61F2/468

  Testing instruments for artificial joints (for testing non-implantable prostheses A61F2/76) · CPC title

• A61F2002/30522

  releasable, e.g. using a releasable ratchet · CPC title

• A61F2/4455

  for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages (intervertebral discs A61F2/442) · CPC title