Method for making hydrogel markers

Patent metadata

Field	Value
Publication number	US-2016374774-A1
Application number	US-201615261607-A
Country	US
Kind code	A1
Filing date	Sep 9, 2016
Priority date	Mar 28, 2006
Publication date	Dec 29, 2016
Grant date	—

Abstract

A hydrogel marker is placed under stress during its curing stage, in one embodiment, by application of an externally applied force. The stress may also be induced during or after the dehydration process. The direction of the externally applied force increases the length, width, depth, or radial extent of the marker. The elastic limit of the marker is exceeded when the external force is applied so that the marker substantially retains its stressed size and shape when the externally applied force is removed. When the stretched or otherwise deformed dehydrated marker is hydrated, it substantially returns to the configuration it had prior to its dehydration and prior to the application of the externally applied force.

First claim

What is claimed is:

1 . A process to make hydrogel which expands in only one direction upon deployment in tissue, said process comprising the step of inducing stress in the hydrogel during a curing process.

2 . The process of claim 1 , wherein the stress is induced in at least one of a radial direction, a height direction, a width direction, and a length direction.

3 . The process of claim 2 , wherein the stress is induced in at least two of a length direction, a height direction, and a width direction.

4 . The process of claim 1 , wherein the stress is induced using a mechanical force.

5 . The process of claim 1 , wherein the stress is induced using a gravitational pull.

6 . The process of claim 1 , wherein the hydrogel comprises a cylindrical marker and the stress is a radial force.

7 . The process of claim 1 , wherein the hydrogel comprises a cylindrical marker and the stress is induced by stretching the hydrogel beyond its elastic limit in a length direction such that the cylindrical marker increases in length and decreases in diameter, and
wherein the stress is induced in the cylindrical marker such that upon deployment in tissue, the cylindrical marker will expand in diameter and contract in length.

8 . The process of claim 1 , further comprising inserting a permanent structure in the hydrogel.

9 . A process to make hydrogel which expands in two directions upon deployment in tissue, said process comprising the step of inducing stress in the hydrogel during a dehydration process.

10 . The process of claim 9 , wherein the stress is induced in at least one of a radial direction, a height direction, a width direction, and a length direction.

11 . The process of claim 9 , further comprising inserting a permanent structure in the hydrogel.

12 . The process of claim 9 , wherein the stress is induced using a mechanical force.

13 . A process to make hydrogel which expands in three directions upon deployment in tissue, said process comprising the step of inducing stress in the hydrogel after dehydration of the polymer has been completed.

14 . The process of claim 13 , wherein the stress is induced in at least one of a radial direction, a height direction, a width direction, and a length direction.

15 . The process of claim 13 , further comprising inserting a permanent structure in the hydrogel.

16 . The process of claim 13 , wherein the stress is induced using a mechanical force.

Assignees

• Devicor Medical Products Inc

Inventors

• Fisher John S

Classifications

• A61B2090/3908

  Soft tissue, e.g. breast tissue · CPC title

• A61B90/39 Primary

  Markers, e.g. radio-opaque or breast lesions markers · CPC title

• A61B2090/3925

  ultrasonic · CPC title

• A61B2090/3991

  having specific anchoring means to fixate the marker to the tissue, e.g. hooks · CPC title

• A61K49/226

  Solutes, emulsions, suspensions, dispersions, semi-solid forms, e.g. hydrogels · CPC title