Variable diameter cannula and methods for controlling insertion depth for medicament delivery

Patent metadata

Field	Value
Publication number	US-9956114-B2
Application number	US-201615383582-A
Country	US
Kind code	B2
Filing date	Dec 19, 2016
Priority date	Jun 20, 2014
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

An apparatus includes a microneedle that defines a lumen therethrough. The microneedle has a proximal end portion a distal end portion and a hub portion between the proximal end portion and the distal end portion. The proximal end portion is configured to be coupled to a medicament container, such as, for example a syringe. The portion of the lumen within the proximal end portion has a first diameter. The distal end portion is configured to pierce a target tissue. The portion of the lumen within the distal end portion has a second diameter smaller than the first diameter. The hub portion includes a surface configured to contact the target tissue when the distal end portion is disposed with the target tissue.

First claim

The invention claimed is:

1. A method, comprising:
inserting a distal end portion of a puncture member of a medical injector into a target tissue to define a delivery passageway within the target tissue and such that a distal end surface of a hub of the medical injector is in contact with a target surface of the target tissue, the distal end portion of the puncture member defining at least a portion of the delivery passageway before the distal end surface of the hub contacts the target surface;
exerting a force on an actuation rod of the medical injector when the distal end surface of the hub is in contact with the target surface, the force having a magnitude of less than a threshold value, the force produces movement of the actuation rod within a medicament container coupled to the medical injector and increases a length of the puncture member extending distally from the distal end surface of the hub when the distal end portion of the puncture member is disposed within a first region of the target tissue and the distal end surface of the hub is in contact with the target surface of the target tissue; and
conveying, in response to the exerting, a substance from the medicament container into the target tissue via the puncture member when the distal end portion of the puncture member is disposed within a second region of the target tissue.

2. The method of claim 1 , wherein the force increases the length of the puncture member extending distally from the distal end surface of the hub when the distal end surface of the hub is in contact with the target surface such that the distal end portion of the puncture member is moved into the second region of the target tissue.

3. The method of claim 1 , wherein movement of the puncture member relative to the distal end surface of the hub in response to the force is limited in response to the distal end portion of the puncture member being disposed within the second region of the target tissue and the distal end surface of the hub is in contact with the target surface of the target tissue.

4. The method of claim 1 , wherein the force is sufficient to overcome a backpressure of the second region such that movement of the distal end portion of the puncture member relative to the hub is reduced and the substance is conveyed into the target tissue when the distal end portion of the puncture member moves from the first region to the second region.

5. The method of claim 1 , wherein:
the threshold value is about 6N,
the target tissue is an eye, the target surface is any one of a conjunctiva of the eye or a sclera of the eye,
the second region includes at least one of a suprachoroidal space, a lower portion of the sclera, a choroid of the eye, a subretinal space of the eye, or a retina of the eye,
the substance being at least one of a VEGF, a VEGF inhibitor, a PDGFR inhibitor, or a combination thereof.

6. The method of claim 1 , further comprising:
during the exerting the force, maintaining a force on the medical injector such that the hub forms a substantially fluid-tight seal with the target surface.

7. The method of claim 1 , wherein:
the force is insufficient to convey the substance from the medicament container into the target tissue via the puncture member when the distal end portion of the puncture member is disposed within the first region of the target tissue.

8. The method of claim 1 , wherein:
before and during the inserting the distal end portion of the puncture member extends distally from the distal end surface of the hub by a first distance,
during the conveying the distal end portion of the puncture member extends distally from the distal end surface of the hub by a second distance greater than the first distance.

9. The method of claim 1 , wherein:
the force increases the length of the puncture member extending distally from the distal end surface of the hub to create or expand the second region.

10. A method, comprising:
inserting a distal end portion of a puncture member of a medical injector into a sclera of an eye to define a delivery passageway within the eye;
exerting a force on an actuation rod of the medical injector when a surface of the medical injector is in contact with a conjunctiva of the eye or the sclera of the eye and the distal end portion of the puncture member is in the sclera the force having a magnitude of less than about 6N, the force (1) produces movement of the actuation rod within a medicament container coupled to the medical injector, and (2) increases a length of the puncture member extending distally from the surface of the medical injector to at least one of create or increase a suprachoroidal space or a subretinal space;
during the exerting the force on the actuation rod, maintaining a force on the medical injector such that the surface of the medical injector forms a substantially fluid-tight seal with the conjunctiva of the eye or the sclera of the eye; and
conveying, in response to the exerting, a substance from the medicament container into the suprachoroidal space or the subretinal space via the puncture member when the distal end portion of the puncture member is disposed within the suprachoroidal space or the subretinal space.

11. The method of claim 10 , wherein the force increases the length of the puncture member extending distally from the surface of the medical injector when the surface of the medical injector is in contact with the conjunctiva of the eye or the sclera of the eye such that the distal end portion of the puncture member is moved into the second region of the eye.

12. The method of claim 10 , wherein movement of the puncture member relative to the surface of the medical injector in response to the force is limited when the distal end portion of the puncture member is disposed within the second region of the eye and the surface of the medical injector is in contact with the conjunctiva of the eye or the sclera of the eye.

13. The method of claim 10 , wherein the force is sufficient to overcome a backpressure of the second region such that movement of the distal end portion of the puncture member relative to the surface of the medical injector is reduced and the substance is conveyed into the eye when the distal end portion of the puncture member moves from the first region to the second region.

14. The method of claim 10 , wherein the second region includes at least one of a suprachoroidal space, a lower portion of the sclera, a choroid of the eye, a subretinal space of the eye, or a retina of the eye.

15. The method of claim 10 , wherein the substance is at least one of a VEGF, a VEGF inhibitor, a PDGFR inhibitor, or a combination thereof.

16. The method of claim 10 , wherein the first region is an upper portion of the sclera of the eye.

17. The method of claim 10 , wherein the inserting includes deforming the conjunctiva of the eye or the sclera of the eye with the surface of the medical injector.

18. The method of claim 10 , wherein the inserting is performed when the exerting is performed.

19. The method of claim 10 , wherein the exerting the force on the actuation rod of the medical injector includes exerting the force without causing the puncture member to contact a vitreous of the eye.

20. The method of claim 10 , wherein the inserting, exerting, maintaining, and conveying are performed without contacting with the puncture member a vitreous body of the eye.

21. A method, comprising:
with a distal end portion of a puncture member of a medical injector extending distally by a fi

Assignees

• Clearside Biomedical Inc

Inventors

• Andino Rafael Victor
• Brooks Christopher John
• Zarnitsyn Vladimir
• White Harrison J

Classifications

• A61P27/02

  Ophthalmic agents · CPC title

• A61M5/329

  characterised by features of the needle shaft · CPC title

• A61M5/46

  having means for controlling depth of insertion · CPC title

• A61F9/0008 Primary

  Introducing ophthalmic products into the ocular cavity or retaining products therein (putting in contact lenses A61F9/0061; introducing or retaining media in cavities of the body in general A61M31/00) · CPC title

• A61M5/158

  Needles {for infusions; Accessories therefor, e.g. for inserting infusion needles, or for holding them on the body} · CPC title