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RU-2861281-C2 - CANNULAE FOR OPHTHALMIC PROCEDURES

RU2861281C2RU 2861281 C2RU2861281 C2RU 2861281C2RU-2861281-C2

Abstract

FIELD: medical technology. SUBSTANCE: group of inventions relates to a cannula system for a surgical procedure. The cannula system for a surgical procedure comprises a valved cannula and a viscous fluid management cannula. The viscous fluid management cannula comprises a proximal segment, an intermediate segment, a first transition region, a distal segment and a second transition region. The proximal segment, the intermediate segment and the distal segment have a common central axis passing through the centre of the cannula device. In a second embodiment, the cannula system for a surgical procedure comprises a valved cannula and an infusion cannula. The infusion cannula comprises a proximal segment, an intermediate segment, a first transition region, a distal segment and a second transition region. The distal segment and the intermediate segment have a first intra-shaft length. The distal segment, the intermediate segment and the proximal segment have a total intra-shaft length. The ratio of the first intra-shaft length to the total intra-shaft length of the cannula device is in the range of 0.2-0.4. EFFECT: enabling injection of a fluid into the eye. 6 cl, 4 dwg

Inventors

  • SINHA, ASHISH
  • HENG, ROBERT JEFFREY

Dates

Publication Date
20260504
Application Date
20220608
Priority Date
20210720

Claims (20)

  1. 1. A cannula system (100) for a surgical procedure, comprising:
  2. a valve cannula (220) comprising a connector (226), a rod (228) and a transition section (230) of the cannula between the connector (226) and the rod (228); and
  3. a viscous fluid control (VFC) cannula (300) comprising:
  4. a proximal segment (302) having a first internal diameter, a first proximal end (303A) and a first distal end (303B); and
  5. an intermediate segment (314) having a second internal diameter that is smaller than the first internal diameter, a second proximal end (315A) and a second distal end (315B);
  6. a first transition portion (306) connecting the proximal segment (302) and the intermediate segment (314) through a first distal end (303B) and a second proximal end (315A), wherein the first transition portion (306) comprises a first concave transition surface (306A) and a second convex transition surface (306B);
  7. a distal segment (304) comprising a third internal diameter smaller than the second internal diameter, a third proximal end (305A) and a third distal end (305B), wherein the third distal end (305B) is configured to be positioned within the valve cannula (220) for injecting, releasing or extracting a fluid through the valve cannula into the ocular space of the eye of a patient, wherein at least a portion of the distal segment (304) is configured to frictionally engage with the inner surface of the shaft (228) of the valve cannula (220); and
  8. a second transition portion (307) connecting the intermediate segment (314) and the distal segment (304) through a second distal end (315B) and a third proximal end (305A), wherein the second transition portion (307) comprises a third transition surface (307A) and a fourth transition surface (307B);
  9. wherein the proximal segment (302), the intermediate segment (314) and the distal segment (304) have a common central axis (312) passing through the center of the cannula device (300);
  10. wherein the distal segment (304), the second transition section (307), the intermediate segment (314) and the second convex transition surface (306B) have a total length (344) inside the rod;
  11. wherein the ratio of the total length (344) inside the rod to the total length (346) of the device (300) in the form of a cannula is in the range of 0.35-0.55; and
  12. wherein the angle of position between the central axis (312) and the tangent line to the first, concave transition surface (306A) at the midpoint is in the range of 20-40 degrees.
  13. 2. The cannula system of claim 1, wherein the ratio of the total length inside the rod (344) to the total length (346) of the cannula device is 0.483.
  14. 3. The cannula system of claim 1, further comprising a third transition portion (308) connecting to the first proximal end (303A), wherein the third transition portion comprises a fifth transition surface (308A).
  15. 4. The cannula system of claim 1, wherein the first transition portion (306) further comprises a first bevel located between the first, concave transition surface and the second bevel or second, convex transition surface.
  16. 5. The cannula system of claim 1, wherein the third distal end further comprises a sixth transition surface or a second bevel.
  17. 6. A cannula system for a surgical procedure, comprising:
  18. a valve cannula (220) comprising a connector (226), a rod (228) and a transition section (230) of the cannula between the connector (226) and the rod (228); and
  19. an infusion cannula (400) configured to be connected to a valve cannula (220) for infusing or releasing a fluid through the valve cannula into the ocular space of the patient's eye, wherein the infusion cannula (400) comprises:
  20. a proximal segment (402) having a first internal diameter (440), a first proximal end (403A) and a first distal end (403B) with a cone;

Description

INTRODUCTION Claim of priority [1] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63/223,645, entitled "CANNULAS FOR OPHTHALMIC PROCEDURES," filed July 20, 2021, and assigned to Ashish Sinha and Robert Jeffrey Heng, which is incorporated herein by reference in its entirety as if fully set forth herein. Field of technology to which the invention relates [2] The present invention generally relates to devices, systems, and methods for monitoring intraocular pressure (IOP) and/or applying ocular tamponades, such as during and/or after ophthalmic surgery. In particular, the present invention relates to ophthalmic cannulas, such as infusion cannulas and injection cannulas, and methods for using them. Background of the invention [3] Posterior segment surgical procedures are performed to treat diseases of the posterior wall of the eye such as age-related macular degeneration (AMD), diabetic retinopathy and diabetic vitreous hemorrhage, macular hole, retinal detachment, epiretinal membrane, cytomegalovirus (CMV) retinitis and others. [4] Certain problems affecting the back of the eye may require vitrectomy, or surgical removal of the vitreous, which is typically the clear, gel-like substance that fills the center of the eye and helps give the eye its appearance and shape. For example, vitrectomy may be performed to clear the eye of blood and debris, remove scar tissue, or relieve traction on the retina. During the procedure, three separate incisions are made in the pars plana (pars plana) of the ciliary body of the eye, which is located just behind the iris but in front of the retina. These incisions are used to pass instruments such as a light pipe, an infusion port, and/or a vitrectomy cutting device into the eye. A valved cannula is placed in each incision to allow the instrument to enter the eye through the cannula while simultaneously providing a self-sealing valve to passively control fluid and pressure communication between the inside and outside of the eye through the cannula. [5] During posterior segment surgery, vitreous fluid is aspirated, intraocular pressure (IOP) decreases, and the patient's eye tends to soften. To maintain IOP and prevent deformation or collapse of the eyeball, an infusion cannula can be connected to the valved cannulas to infuse a fluid, such as liquid or gas (e.g., balanced salt solution (BSS)), into the eye. Additionally, maintaining IOP can help maintain scleral rigidity to facilitate eye movement and instrument changes during the procedure. However, IOP must be carefully regulated, as prolonged periods of elevated IOP can damage ocular structures. If the IOP becomes too high, another infusion cannula can be used to drain fluid from the eye and relieve pressure. [6] In another example, an injection cannula can be connected to the valved cannula and used to inject a viscous fluid, such as an ocular tamponade, into the ocular space to prevent fluid leakage through the retinal break. The tamponade can replace the vitreous fluid removed during vitrectomy and can be a gas or a solution (e.g., silicone oil). After the procedure, the tamponade can remain in the patient's eye for a period of time, after which it can be removed. [7] Traditional fluid cannulas (e.g., infusion cannulas, injection cannulas, etc.) have various disadvantages. For example, traditional fluid cannulas are typically sized specifically, with each cannula being sized to fit a specific gauge of the valve cannula to which the fluid cannula is intended to be connected. Valve cannulas are available in several different gauges (e.g., 23 gauge, 25 gauge, and 27 gauge), so for a surgical procedure, the user (e.g., an ophthalmic surgeon) must have available a fluid cannula sized specifically to fit the required valve cannula. The use of valve cannulas of different sizes adds inconvenience to the surgical procedure. Additionally, traditional fluid cannula designs create relatively high hydraulic friction for the fluids passing through them. High hydraulic friction limits the overall fluid flow and requires higher pressures to maintain a given fluid flow rate. Operating at higher pressures may require larger pumps and may cause additional wear and tear on equipment. In some cases, the limitations of traditional tubing assemblies and systems for delivering viscous fluids at high pressures can lead to failure, including rupture and disconnection. Furthermore, operating at lower pressures minimizes the risk of ocular tissue injury. [8] Therefore, there is a need for improved devices, systems and methods for monitoring IOP and applying fluids, and in particular, there is a need for improved fluid cannulas to eliminate at least some of the above-described deficiencies. ESSENCE OF THE INVENTION [9] The present invention generally relates to devices, systems, and methods for monitoring intraocular pressure during ophthalmic surgery, such as surgical procedures on the posterior segment of the eye