EP-4739374-A1 - THIN WALL CANNULA

EP4739374A1EP 4739374 A1EP4739374 A1EP 4739374A1EP-4739374-A1

Abstract

A medical injection cannula configured for use with a syringe includes a sidewall defining a lumen and having a proximal end and a distal end, and a beveled tip defining an opening to the lumen. A length-to-diameter ratio of the cannula is defined by a ratio, wherein L hydrodynamic theoretical needle is a theoretical hydrodynamic length of the cannula, and D needle_inner is an inner diameter of the sidewall of the cannula. The length-to-diameter ratio is between 7.00x10 11 and 9.40x10 12 m -3 .

Inventors

LEANG, Sandra
DUINAT, BRIGITTE
FREMON, BENOIT
PRAIS, ALFRED, W.

Assignees

Becton Dickinson France
Becton, Dickinson and Company

Dates

Publication Date: 20260513
Application Date: 20240628

Claims (1)

Attorney Docket No. 04684-2402733 (P-28336.WO01) THE INVENTION CLAIMED IS 1. A medical injection cannula configured for use with a syringe, the cannula comprising: a sidewall defining a lumen and having a proximal end and a distal end; and a beveled tip defining an opening to the lumen, wherein a length-to-diameter ratio of the cannula is defined by a ratio: 8 9:;*';:<5=>? &9)'*)&>?56 <));6) 3 7 <));6)_><<)* wherein Lhydrodynamic theoretical needle is a theoretical hydrodynamic length of the cannula, and Dneedle_inner is an inner diameter of the sidewall of the cannula; wherein an outer diameter of the sidewall corresponds to a cannula standard for a 27G cannula; and wherein the length-to-diameter ratio is comprised between 7.00x10 11 and 1.60x10 12 m -3 . 2. The medical injection cannula of claim 1, wherein when an exposed needle length of the medical injection cannula is 8mm, the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ ^ ^ ^^^^^^_^^^^^ is comprised between 8.00x10 11 m -3 and 1.40x10 12 m -3 . 3. The medical injection cannula of claim 1, wherein when an exposed needle length of the medical injection cannula is 6mm, the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ ^ ^ ^^^^^^_^^^^^ is comprised between 7.00x10 11 m -3 and 1.20x10 12 m -3 . 4. The medical injection cannula of claim 1, wherein when an exposed needle length of the medical injection cannula is 10mm, the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ ^ ^ ^^^^^^_^^^^^ is comprised between 1.00x10 12 m -3 and 1.60x10 12 m -3 . 5. The medical injection cannula of any of claims 1 to 4, wherein the theoretical hydrodynamic length of the cannula L hydrodynamic extends from the proximal end of the sidewall to a proximal end of the opening of the beveled tip. 5VG0091.DOCX 15 Attorney Docket No. 04684-2402733 (P-28336.WO01) 6. The medical injection cannula of any of claims 1 to 5, wherein the outer diameter of the sidewall is substantially constant between the proximal end and the distal end. 7. A medical injection cannula configured for use with a syringe, the cannula comprising: a sidewall defining a lumen and having a proximal end and a distal end; and a beveled tip defining an opening to the lumen, wherein a length-to-diameter ratio of the cannula is defined by a ratio: 8 9:;*';:<5=>? &9)'*)&>?56 <));6) 3 7 <));6)_><<)* wherein Lhydrodynamic theoretical needle is a theoretical hydrodynamic length of the cannula, and D needle_inner is an inner diameter of the sidewall of the cannula; wherein an outer diameter of the sidewall corresponds to a cannula standard for a 29G cannula; and wherein the length-to-diameter ratio is comprised between 2.10x10 12 and 4.70x10 12 m -3 . 8. The medical injection cannula of claim 7, wherein when an exposed needle length of the medical injection cannula is 8mm, the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ ^ ^ ^^^^^^_^^^^^ is comprised between 2.50x10 12 m -3 and 4.10x10 12 m -3 . 9. The medical injection cannula of claim 7, wherein when an exposed needle length of the medical injection cannula is 6mm, the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ ^ ^ ^^^^^^_^^^^^ is comprised between 2.10x10 12 m -3 and 3.50x10 12 m -3 . 10. The medical injection cannula of claim 7, wherein when an exposed needle length of the medical injection cannula is 10mm, the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ ^ ^ ^^^^^^_^^^^^ is comprised between 3.00x10 12 m -3 and 4.70x10 12 m -3 . 11. The medical injection cannula of any of claims 7 to 10, wherein the theoretical hydrodynamic length of the cannula Lhydrodynamic extends from the proximal end of the sidewall to a proximal end of the opening of the beveled tip. 5VG0091.DOCX 16 Attorney Docket No. 04684-2402733 (P-28336.WO01) 12. The medical injection cannula of any of claims 7 to 11, wherein the outer diameter of the sidewall is substantially constant between the proximal end and the distal end. 13. A medical injection cannula configured for use with a syringe, the cannula comprising: a sidewall defining a lumen and having a proximal end and a distal end; and a beveled tip defining an opening to the lumen, wherein a length-to-diameter ratio of the cannula is defined by a ratio: 8 9:;*';:<5=>? &9)'*)&>?56 <));6) 3 7 <));6)_><<)* wherein L hydrodynamic theoretical needle is a theoretical hydrodynamic length of the cannula, and Dneedle_inner is an inner diameter of the sidewall of the cannula; wherein an outer diameter of the sidewall corresponds to a cannula standard for a 30G cannula; and wherein the length-to-diameter ratio is comprised between 4.10x10 12 and 9.40x10 12 m -3 . 14. The medical injection cannula of claim 13, wherein when an exposed needle length of the medical injection cannula is 8mm, the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ ^ ^ ^^^^^^_^^^^^ is comprised between 4.90x10 12 m -3 and 8.20x10 12 m -3 . 15. The medical injection cannula of claim 13, wherein when an exposed needle length of the medical injection cannula is 6mm, the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ ^ ^ ^^^^^^_^^^^^ is comprised between 4.10x10 12 m -3 and 7.00x10 12 m -3 . 16. The medical injection cannula of claim 13, wherein when an exposed needle length of the medical injection cannula is 10mm, the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ ^ ^ ^^^^^^_^^^^^ is comprised between 5.70x10 12 m -3 and 9.40x10 12 m -3 . 5VG0091.DOCX 17 Attorney Docket No. 04684-2402733 (P-28336.WO01) 17. The medical injection cannula of any of claims 13 to 16, wherein the theoretical hydrodynamic length of the cannula Lhydrodynamic extends from the proximal end of the sidewall to a proximal end of the opening of the beveled tip. 18. The medical injection cannula of any of claims 13 to 17, wherein the outer diameter of the sidewall is substantially constant between the proximal end and the distal end. 5VG0091.DOCX 18

Description

Attorney Docket No. 04684-2402733 (P-28336.WO01) THIN WALL CANNULA CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application claims priority to European Patent Application No. 23183866.5 entitled “Thin Wall Cannula” filed July 6, 2023, and also claims priority to European Patent Application No. 24305165.3 entitled “Thin Wall Cannula” filed January 30, 2024, the disclosures of which are hereby incorporated by reference in their entireties. BACKGROUND OF THE INVENTION Field of the Invention [0002] The present disclosure relates to cannulas for syringes and other medical devices. Description of Related Art [0003] Cannulas are a ubiquitous component of modern medical care. Cannulas are used for example, to pierce a patient’s skin to create a vascular access site for the administration of medicaments and other fluids (e.g., saline), or to withdraw blood from the patient. To reduce patient discomfort and the risk of injury, the outer diameter of cannulas is desirably minimized. However, the lumen of the cannula must be of sufficient diameter to allow the medicament or other fluid to flow through the cannula at an adequate rate, whatever the viscosity of the injected drug. As such, it is desirable to produce cannula with thin sidewalls to minimize the outer diameter while maximizing the inner diameter. SUMMARY [0004] Embodiments of the present disclosure are directed to a medical injection cannula configured for use with a syringe. The cannula includes a sidewall defining a lumen and having a proximal end and a distal end, and a beveled tip defining an opening to the lumen, wherein a length-to-diameter ratio of the cannula is defined by a ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ ^ ^ ^^^^^^_^^^^^ , wherein Lhydrodynamic theoretical needle is a theoretical hydrodynamic length of the cannula, and Dneedle_inner is an inner diameter of the sidewall of the cannula, and wherein the length-to- diameter ratio is comprised between 7.00x1011 and 9.40x1012 m-3. [0005] In accordance with an embodiment, wherein the theoretical hydrodynamic length of the cannula Lhydrodynamic extends from the proximal end of the sidewall to a proximal end of the opening of the beveled tip. 5VG0091.DOCX 1 Attorney Docket No. 04684-2402733 (P-28336.WO01) [0006] In accordance with an embodiment, the outer diameter of the sidewall corresponds to a cannula standard for a 27G, 29G or 30G cannula. [0007] In accordance with an embodiment, the outer diameter of the sidewall is for the 27G cannula and the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ 11 -3 ^ ^ ^^^^^^_^^^^^ is comprised between 8.00x10 m and 1.4x1012 m-3. [0008] In accordance with an embodiment, the outer diameter of the sidewall is for the 29G cannula and the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ 12 -3 ^ ^ ^^^^^^_^^^^^ is comprised between 2.50x10 m and 4.10x1012 m-3. [0009] In accordance with an embodiment, the outer diameter of the sidewall is for the 30G cannula and the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ ^^^^^^^_^^^^^^ is comprised between 4.90x1012 m-3 and8.20x1012 m-3. [0010] In accordance with an embodiment, the outer diameter of the sidewall is for the 27G cannula and the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ is comprised betwee 11 -3 ^^^^^^^_^^^^^^ n 7.00x10 m and1.20x1012 m-3. [0011] In accordance with an embodiment, the outer diameter of the sidewall is for the 29G cannula and the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ is co 12 -3 ^ ^ ^^^^^^_^^^^^ mprised between 2.10x10 m and3.50x1012 m-3. [0012] In accordance with an embodiment, the outer diameter of the sidewall is for the 30G cannula and the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ 12 -3 ^^^^^^^_^^^^^^ is comprised between 4.10x10 m and7.00x1012 m-3. [0013] In accordance with an embodiment, the outer diameter of the sidewall is for the 27G cannula and the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ 12 ^_^^^^^ is compri -3 ^^^^^^ ^ sed between 1.00x10 m and1.60x1012 m-3. [0014] In accordance with an embodiment, the outer diameter of the sidewall is for the 29G cannula and the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ is comprised between 3.00x1 12 -3 ^ ^ ^^^^^^_^^^^^ 0 m and4.70x1012 m-3. [0015] In accordance with an embodiment, the outer diameter of the sidewall is for the 30G cannula and the ratio ^^^^^^^^^^^^^ ^^^^^^^^^^^ ^^^^^^ is comprised b 12 -3 ^^^^^^^_^^^^^^ etween 5.70x10 m and9.40x1012 m-3. 5VG0091.DOCX 2 Attorney Docket No. 04684-2402733 (P-28336.WO01) [0016] In accordance with an embodiment, the outer diameter of the sidewall is substantially constant between the proximal end and the distal end. [0017] Also provided herein is a medical injection assembly including a syringe having a sidewall and a distal end, and a cannula connected to the distal end. The cannula further includes a sidewall defining a lumen and having a proximal end and a distal end and a beveled tip defining an opening to the lumen, wherein a flow factor K1 of a fluid through the lumen of the cannula is approximated by the equation ,