# US 9,750,581 B2 · Method for enhancing ultrasound visibility of hyperechoic materials

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- Number: US 9,750,581 B2
- Document ID: US9750581B2
- Status: Granted
- Kind: B2
- Application number: 15/159,598
- Filed: 2016-05-19
- Published: 2016-09-15
- Granted: 2017-09-05
- Earliest claimed: 2006-03-28
- Assignees: Devicor Medical Products, Inc.
- Applicants: Devicor Medical Products, Inc.
- Inventors: Frederick A. Ahari; John S. Fisher
- Web page: https://patentgrep.com/patent/US9750581B2

## CPC

- A61B 90/39: {Markers, e.g. radio-opaque or breast lesions markers}
- A61F 2/02: Prostheses implantable into the body
- A61K 49/226: {Solutes, emulsions, suspensions, dispersions, semi-solid forms, e.g. hydrogels}
- A61L 31/06: obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds {(A61L31/041 takes precedence)}
- A61L 31/145: {Hydrogels or hydrocolloids}
- A61B 2090/3908: {Soft tissue, e.g. breast tissue}
- A61B 2090/3925: {ultrasonic}
- A61B 2090/3995: {Multi-modality markers}
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C)
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- 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)

## Abstract

A hydrogel plug 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 plug. The elastic limit of the plug is exceeded when the external force is applied so that the plug substantially retains its stressed size and shape when the externally applied force is removed. When the stretched or otherwise deformed dehydrated plug is hydrated, it substantially returns to the configuration it had prior to its dehydration and prior to the application of the externally applied force.

## Claims

### Claim 1

A method for making a hydrogel plug that contracts in a controlled manner when hydrated, comprising:
forming said hydrogel plug so that it has a predetermined geometric configuration when in a repose configuration;
subjecting said hydrogel plug to a dehydration process;
inducing stress into said hydrogel plug during said dehydration process by applying an external force;
controlling said stress so that said hydrogel plug is stretched beyond its elastic limit and assumes and retains a stretched preselected geometrical configuration;
removing said externally applied force during the dehydration process so that the hydrogel plug substantially retains said stretched predetermined geometrical configuration before the dehydration process is concluded; and
curing said dehydrated hydrogel plug;
wherein the cured and dehydrated hydrogel plug, when hydrated, contracts until assuming the in repose configuration, and
wherein curing said dehydrated hydrogel plug comprises curing said dehydrated hydrogel plug inside a core of a coil and between loops of the coil to achieve a selected coverage of a hyperechoic marker.

### Claim 2 (depends on 1)

The method of claim 1, further comprising:
applying said external force to said hydrogel plug during said dehydration process by subjecting said hydrogel plug to a force coincident with a longitudinal axis of said hydrogel plug;
wherein said cured and dehydrated hydrogel plug, when hydrated, contracts only in a longitudinal direction.

### Claim 3 (depends on 2)

The method of claim 2, further comprising:
inducing said stress into said hydrogel plug during said dehydration process by subjecting said hydrogel plug to an externally applied force coincident with a transverse axis of said hydrogel plug, said transverse axis being normal to said longitudinal axis;
wherein said cured and dehydrated hydrogel plug, when hydrated, contracts only in a transverse direction.

### Claim 4 (depends on 3)

The method of claim 3, further comprising:
inducing said stress into said hydrogel plug during said dehydration process by subjecting said hydrogel plug to an externally applied force coincident with an axis normal to said longitudinal axis and normal to said transverse axis of said hydrogel plug;
wherein said cured and dehydrated hydrogel plug, when hydrated, contracts only in a direction normal to said longitudinal axis and normal to said transverse axis.

### Claim 5 (depends on 4)

The method of claim 4, further comprising:
inducing said stress into said hydrogel plug during said dehydration process by subjecting said hydrogel plug to an externally applied radial force, said radial force causing said hydrogel plug to expand radially relative to a longitudinal axis and to contract in length along said longitudinal axis;
determining a radial expansion to longitudinal contraction ratio;
said cured and dehydrated hydrogel plug, when hydrated, contracting in a radial direction relative to said longitudinal axis and contracts in length along said longitudinal axis when hydrated; and
measuring the amount of radial expansion and the amount of longitudinal contraction and dividing the radial expansion by the longitudinal contraction to derive a radial expansion to longitudinal contraction ratio.