Blood suction syringe with anti-hemolysis function

Abstract

The blood collection device may include a syringe with hemolysis prevention. The syringe with hemolysis prevention may be coupled to the catheter assembly and used for blood aspiration. The blood collection device may include a syringe, which may include a distal end and a flow restrictor. The flow restrictor may include a distal end and a proximal end. The proximal end of the flow restrictor may be coupled to the distal end of the syringe, which may provide protection against hemolysis.

Description

[Background technology]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application Serial No. 63 / 090,602, entitled "Blood Aspiration Syringe with Hemolysis Prevention Function," filed October 12, 2020, the entire disclosure of which is incorporated herein by reference in its entirety.

[0002] background Catheters are commonly used to infuse fluids into a patient's vascular system. For example, catheters may be used to infuse normal saline, various medications, or total parenteral nutrition.

[0003] The catheter may include a peripheral intravenous ("IV") catheter. In this case, the catheter may be mounted over an introducer needle having a sharp distal tip. The catheter and introducer needle may be assembled such that the distal tip of the introducer needle extends beyond the distal tip of the catheter, with the bevel of the needle pointing up, away from the patient's skin. The catheter and introducer needle are inserted through the skin into the patient's vascular system at a generally shallow angle.

[0004] To confirm that the introducer needle and / or catheter are properly placed within the blood vessel, the practitioner will typically check for a "flashback" of blood in the flashback chamber of the catheter assembly. Once needle placement is confirmed, the practitioner may remove the introducer needle, leaving the catheter in place for future fluid injections. Summary of the Invention [Problem to be solved by the invention]

[0005] Blood aspiration through peripheral venous catheters is not routinely performed, in large part due to the risk of hemolysis in blood samples drawn through peripheral venous catheters. When blood aspiration is performed through a peripheral venous catheter, a commonly used blood collection container is the VACUTAINER® blood collection tube, available from Becton Dickinson & Company. In some cases, a syringe may be used instead. However, syringes have not been shown to reduce the risk of hemolysis compared to VACUTAINER®.

[0006] Unfortunately, when blood is drawn into the syringe or VACUTAINER®, red blood cells are subject to high shear stress due to the high pressure differential between the vein and the syringe or VACUTAINER®, making them susceptible to hemolysis. Hemolysis may lead to rejection and discarding of the blood sample. High pressure differentials may also cause catheter tip collapse, vein collapse, or other complications.

[0007] The subject matter claimed herein is not limited to embodiments that solve any shortcomings or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one example technology area in which some embodiments described herein may be practiced. [Means for solving the problem]

[0008] overview The present disclosure generally relates to blood collection devices and related devices, systems, and methods. In some embodiments, the blood collection device may include a catheter assembly, which may include a catheter adapter and a catheter extending distally from the catheter adapter. In some embodiments, the blood collection system may include a blood collection device coupled to the catheter assembly. In some embodiments, the blood collection device may include a syringe, which may include a distal end. In some embodiments, the blood collection device may include a flow restrictor, which may include a distal end and a proximal end. In some embodiments, the proximal end of the flow restrictor may be coupled to the distal end of the syringe.

[0009] In some embodiments, the catheter assembly may include an extension tube. In some embodiments, the distal end of the extension tube may be integral with the catheter adapter. In some embodiments, the blood collection device may be coupled to the proximal end of the extension tube.

[0010] In some embodiments, the distal end of the syringe may include a first Luer adapter. In some embodiments, the proximal end of the flow restrictor may include a second Luer adapter coupled to the first Luer adapter. In some embodiments, the flow restrictor may be monolithically formed as a single unit. In these and other embodiments, the distal end of the flow restrictor may include a third Luer adapter.

[0011] In some embodiments, the distal end of the flow restrictor may include a third Luer adapter. In these and other embodiments, the flow restrictor may include an extension tube disposed between the second Luer adapter and the third Luer adapter. In these and other embodiments, the flow restrictor may include a first piece monolithically formed as a single unit and a second piece monolithically formed as a single unit. In some embodiments, the proximal end of the extension tube may be integrated within the first piece. In some embodiments, the distal end of the extension tube may be integrated within the second piece. In some embodiments, the first piece may include the second Luer adapter. In some embodiments, the second piece may include the third Luer adapter.

[0012] In some embodiments, the geometric factor of the flow restrictor is G f In some embodiments, G f is 1.43E7 1 / in 3 ±30% (8.73E5 1 / cm 3 ±30%) In some embodiments, G f is 3.70E6 1 / in 3 ±30% (2.26E5 1 / cm 3 ±30%) In some embodiments, G f In some embodiments, G f is 1.43E7 1 / in 3 ±10% (8.73E5 1 / cm 3 ±10%) or 3.70E6 1 / in 3 ±10% (2.26E5 1 / cm 3 ±10%) may be.

[0013] In some embodiments, the flow restrictor may include a fluid path extending through the flow restrictor. In some embodiments, the diameter of the fluid path may be uniform along the entire length of the fluid path. In these embodiments, the diameter is represented by D, the length is represented by L, and D 4 / L may be 2.7E-7 or 7.0E-8.

[0014] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention as claimed. It is to be understood that the various embodiments are not limited to the arrangement and instrumentality shown in the drawings. It is also to be understood that the embodiments may be combined or other embodiments may be utilized, and structural changes may be made without departing from the scope of the various embodiments of the invention, unless so claimed. Therefore, the following detailed description is not to be taken in a limiting sense.

[0015] BRIEF DESCRIPTION OF THE DRAWINGS The illustrative embodiments will be detailed and explained with additional specificity and detail through the use of the accompanying drawings. [Brief explanation of the drawings]

[0016] [Figure 1A] FIG. 1A is a top perspective view of an exemplary blood collection device including hemolysis protection, according to some embodiments. [Figure 1B] FIG. 1B is a cross-sectional view of the blood collection device of FIG. 1A, according to some embodiments. [Figure 2A] FIG. 2A is a top perspective view of another exemplary blood collection device including hemolysis protection, according to some embodiments. [Figure 2B] FIG. 2B is a cross-sectional view of the blood collection device of FIG. 2A, according to some embodiments. [Figure 3] FIG. 3 is a top perspective view of an exemplary blood collection system, according to some embodiments. [Figure 4]FIG. 4 is a bar graph illustrating blood collection rates with various catheter gauges and flow restrictors under different syringe aspiration rates, according to some embodiments. [Figure 5] FIG. 5 is a bar graph showing maximum shear stress with various catheter gauges and flow restrictors under different syringe aspiration rates, according to some embodiments. [Figure 6] FIG. 6 is a graph showing plasma free hemoglobin for catheter assemblies with and without a flow restrictor, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0017] Description of the embodiment In some embodiments, blood collection device 10 may include syringe 12, which may include a distal end 14 and a proximal end 16. In some embodiments, syringe 12 may include a sliding plunger 18 that fits tightly within a barrel or tube 20. In some embodiments, sliding plunger 18 may be pulled proximally relative to tube 20, allowing syringe 12 to aspirate a liquid, such as blood, through an orifice 22 in distal end 14. In some embodiments, sliding plunger 18 may be pushed distally relative to tube 20, allowing syringe 12 to then expel the liquid through orifice 22. In some embodiments, syringe 12 may be configured to hold approximately 1 to 20 milliliters of liquid.

[0018] In some embodiments, the blood collection device 10 may include a flow restrictor 24, which may include a distal end 26 and a proximal end 28. In some embodiments, the proximal end 28 of the flow restrictor 24 may be coupled to the distal end 14 of the syringe 12. In some embodiments, the flow restrictor 24 may be removably coupled to the distal end 14 of the syringe 12. In other embodiments, the flow restrictor 24 may be permanently coupled to the distal end 14 of the syringe 12.

[0019] In some embodiments, the distal end 14 of the syringe 12 may include a first Luer adapter 30. In some embodiments, the proximal end 16 of the flow restrictor 24 may include a second Luer adapter 32 coupled to the first Luer adapter 30. In some embodiments, the first Luer adapter 30 may include a male Luer adapter, which may be engaged with a threaded connection or a slip fit with the second Luer adapter 32, which may include a female Luer adapter. In some embodiments, the threaded connection between the first Luer adapter 30 and the second Luer adapter 32 may prevent accidental uncoupling of the syringe 12 from the flow restrictor 24 during blood collection.

[0020] In some embodiments, the flow restrictor 24 may be monolithically formed as a single unit, as shown, for example, in FIGS. 1A-1B. In these and other embodiments, the distal end 26 of the flow restrictor 24 may include a third luer adapter 34. In some embodiments, the third luer adapter 34 may include a male luer adapter. In some embodiments, the distal end 26 of the flow restrictor 24 may be configured to couple to a catheter assembly, which may be inserted into a patient's vasculature. In some embodiments, the sliding plunger 18 may be pulled proximally to aspirate blood from the patient's vasculature into the tube 20 of the syringe 12.

[0021] In some embodiments, the length of the flow restrictor 24 may be shorter than the length of the syringe 12 to facilitate easy handling by the user. In some embodiments, the flow restrictor 24 may include a fluid pathway 36 extending therethrough. Generally, blood cells experience shear stress as the blood flows through the fluid pathway. The maximum shear stress is along the wall of the blood cell, i.e., wall shear stress. Wall shear stress of blood cells is believed to be a major cause of hemolysis and mechanical damage to blood cells.

[0022] In some embodiments, flow restrictor 24 may provide hemolysis protection. More specifically, flow restrictor 24 may limit the maximum blood collection rate, which may in turn limit the maximum shear stress during blood collection to reduce hemolysis. In some embodiments, flow restrictor 24 may be configured to limit the maximum shear stress to which blood cells are exposed during aspiration by the syringe to a predetermined or target value.

[0023] The flow of fluid in a flow restrictor with a tubular fluid path passing through it is governed by the Poiseuille equation:

[0024]

number

[0025] where P is the change in pressure gradient across the flow restrictor, D and L are the inner diameter and length of the fluid path 36 through the flow restrictor, respectively, μ is the viscosity of the fluid, and R f =128μL / πD 4 is the fluid resistance. μ is the viscosity of the fluid and is not part of the flow restrictor geometry, so the geometric coefficient G f is R f (fluid resistance) is R f =128μL / π G f where G f =L / D 4 In some embodiments, the flow restrictor may include flow restrictor 24 or flow restrictor 38 (see, eg, FIGS. 2A-2B).

[0026] Since the fluid path 36 has multiple sections with lengths (L1, L2, L3) and inner diameters (D1, D2, D3), the fluid resistance is:

[0027]

number

[0028] In some embodiments, the flow restrictor is G fFor example, the flow restrictor 24 may be configured to restrict G f is approximately 1.43E7 1 / in 3 In some embodiments, for the flow restrictor 24, G f is 1.43E7 1 / in 3 ±10% (8.73E5 1 / cm 3 ±10%) or 1.43E7 1 / in 3 ±30% (8.73E5 1 / cm 3 ±30%) may be.

[0029] In some embodiments, the inner diameter of the fluid pathway 36 may be uniform along the entire length of the fluid pathway 36. In some embodiments, D4 / L is about 2.7E-7, which may reduce wall shear stress and reduce hemolysis when the flow restrictor 24 is used with a 20G catheter. 4 / L is approximately 7.0E-8, which may reduce wall shear stress and reduce hemolysis when flow restrictor 24 is used with a 22G catheter.

[0030] 2A-2B, in some embodiments, blood collection device 10 may include a flow restrictor 38. In some embodiments, flow restrictor 38 may be similar or identical in one or more characteristics and / or operation to flow restrictor 24. In some embodiments, flow restrictor 38 may be G f For example, the flow restrictor 38 may be configured to restrict G f is approximately 3.70E6 1 / in 3 (2.26E5 1 / cm 3 ) In some embodiments, for the flow restrictor 38, G f is 3.70E6 1 / in 3 ±10% (2.26E5 1 / cm 3±10%) or 3.70E6 1 / in 3 ±30% (2.26E5 1 / cm 3 ±30%) In some embodiments, a particular flow restrictor, such as flow restrictor 24 or flow restrictor 38, may have a G f In some embodiments, the inner diameter of the fluid pathway 36 may be variable along the length of the fluid pathway 36. In these and other embodiments, the flow restrictor 38 may include multiple tubes having different inner diameters joined together or multiple sections formed from a single tube whose inner diameter varies along its length.

[0031] In some embodiments, the distal end 26 of the flow restrictor 38 may include the third Luer adapter 34. In these and other embodiments, the flow restrictor 38 may include an extension tube 44 disposed between the second Luer adapter 32 and the third Luer adapter 34. In these and other embodiments, the flow restrictor 38 may include a first piece 40 monolithically formed as a single unit and / or a second piece 42 monolithically formed as a single unit. In some embodiments, the proximal end of the extension tube 44 may be integrated within the first piece 40. In some embodiments, the distal end of the extension tube 44 may be integrated within the second piece 42. In some embodiments, the first piece 40 may include the second Luer adapter 32. In some embodiments, the second piece 42 may include the third Luer adapter 34.

[0032] In some embodiments, the length of the flow restrictor 38 may be shorter than the length of the syringe 12 to facilitate easier handling by the user. In some embodiments, the flow restrictor 38 may include a fluid pathway 36 that extends through the flow restrictor 24. In some embodiments, the inner diameter of the fluid pathway 36 may be uniform along the entire length of the fluid pathway 36. In some embodiments, the inner diameter is represented by D, the length is represented by L, and D 4 / L is 2.7E-7, which may reduce wall shear stress and reduce hemolysis when flow restrictor 38 is used with a 20G catheter. In some embodiments, the inner diameter is represented by D, the length is represented by L, and D 4 / L is 7.0E-8, which may reduce wall shear stress and reduce hemolysis when flow restrictor 38 is used with a 22G catheter.

[0033] 3, a flow restrictor, such as flow restrictor 24 (see, e.g., FIGS. 1A-1B) or flow restrictor 38 (see, e.g., FIGS. 2A-2B), may be coupled to a catheter assembly 46. In some embodiments, catheter assembly 46 may include a catheter adapter 48 and a catheter 50 extending distally from catheter adapter 48. In some embodiments, catheter assembly 46 may include an extension tube 52. In some embodiments, the distal end of extension tube 52 may be integral with catheter adapter 48. In some embodiments, blood collection device 10 may be coupled to the proximal end of extension tube 52.

[0034] In some embodiments, the needle assembly 54 may be coupled to the catheter assembly 46. In some embodiments, the needle assembly 54 may include a needle hub 56 and an introducer needle 58 secured within the needle hub 56. In some embodiments, the needle assembly 54 may be detached from the catheter assembly 46 upon insertion of the catheter 50 into the patient's vasculature. In some embodiments, the proximal end of the extension tube 52 may be integrated with a side port 60 of the catheter adapter 48.

[0035] In some embodiments, catheter assembly 46 may include or correspond to any suitable catheter assembly, such as, for example, a BD NEXIVA™ Closed IV Catheter System, a BD CATHENA™ Catheter System, a BD VENFLON™ Pro Safety Shielded IV Catheter System, a BD NEOFLON™ IV Cannula System, a BD INSYTE™ AUTOGUARD™ BC Shielded IV Catheter System, or another suitable catheter assembly. In some embodiments, catheter 50 may include a peripheral intravenous catheter (PIVC), a peripherally inserted central catheter (PICC), a midline catheter, or another suitable catheter.

[0036] In some embodiments, in response to insertion of the catheter 50 into the vascular system, blood may flow to the proximal end through a fluid path of the catheter assembly 46, which may include one or more of the catheter 50, the catheter adapter 48, the extension tube 52, the adapter 62, the flow restrictor, and the syringe 12.

[0037] Referring now to FIG. 4, a bar graph illustrates blood collection rates with various catheter gauges and flow restrictors under different syringe aspiration rates, according to some embodiments. "Hemoshield 1" refers to a first exemplary flow restrictor coupled to a catheter assembly. Hemoshield 1 may include flow restrictor 24 of FIGS. 1A-1B or flow restrictor 38 of FIGS. 2A-2B coupled to the catheter assembly. In this example, the D^4 / L of Hemoshield 1 is approximately 7e-8, although the D^4 / L may vary. "Hemoshield 2" refers to another exemplary flow restrictor coupled to a catheter assembly. Hemoshield 2 may include flow restrictor 24 of FIGS. 1A-1B or flow restrictor 38 of FIGS. 2A-2B coupled to the catheter assembly. In this example, the D^4 / L of Hemoshield 2 is approximately 2.7e-8, although the D^4 / L may vary. "None" refers to a catheter assembly without a flow restrictor coupled to it.

[0038] Without a flow restrictor, blood flow rate varies significantly with syringe aspiration rate. However, with the use of a flow restrictor (Hemoshield 1 and Hemoshield 2 in the experiments), the flow rate through the catheter during blood collection becomes independent of syringe aspiration rate. This, according to some embodiments, significantly reduces syringe aspiration variability in a clinical setting.

[0039] FIG. 5 is a bar graph showing maximum shear stress with various catheter gauges and flow restrictors under different syringe aspiration rates, according to some embodiments. Again, "Hemo-Shield 1" refers to the first example flow restrictor coupled to a catheter assembly. Hemo-Shield 1 may include flow restrictor 24 of FIGS. 1A-1B or flow restrictor 38 of FIGS. 2A-2B coupled to a catheter assembly. In this example, the D^4 / L of Hemo-Shield 1 is approximately 7e-8, although the D^4 / L may vary. "Hemo-Shield 2" refers to another example flow restrictor coupled to a catheter assembly. Hemo-Shield 2 may include flow restrictor 24 of FIGS. 1A-1B or flow restrictor 38 of FIGS. 2A-2B coupled to a catheter assembly. In this example, the D^4 / L of Hemo-Shield 2 is approximately 2.7e-8, although the D^4 / L may vary. "None" refers to a catheter assembly without a flow restrictor coupled to it. "UT 21G" refers to a prior art catheter assembly having a 21G catheter.

[0040] The resulting maximum shear stress for each catheter gauge can be expressed as a ratio to the maximum shear stress of the UT21G with VACUTAINER®, which was previously considered the gold standard for blood aspiration. Because shear stress leads to mechanical hemolysis, reducing the shear stress of catheter aspiration to that of the UT21G reduces the risk of hemolysis. Data show that with 18G catheters, the risk of hemolysis is low when aspirating blood using a syringe. However, as the catheter gauge increases, the risk of hemolysis also increases. For 20G catheters, the risk of hemolysis is moderate at low syringe retraction rates but increases with increasing retraction rates. With a flow restrictor with a D^4 / L of 2.7e-7, the maximum shear from catheter aspiration is reduced to the maximum shear of the 21G UT at all syringe aspiration rates tested. For 22G catheters, the risk of hemolysis is significant at higher aspiration rates. A flow restrictor with a D^4 / L of 7e-8 again reduces the shear rate to the gold standard at all syringe aspiration rates tested. With a 24G catheter, the tested flow restrictors are able to reduce maximum shear stress by 2.5-3x depending on syringe aspiration rate.

[0041] Figure 6 is a graph showing plasma free hemoglobin for catheter assemblies with and without a flow restrictor, according to some embodiments. "IAG" refers to a prior art catheter assembly, i.e., the INSYTE™ AUTOGUARD™ BC Shield IV Catheter, available from Becton Dickinson & Company, Franklin Lakes, New Jersey. "IAG+H" refers to a prior art catheter assembly coupled to a flow restrictor, such as flow restrictor 24 in Figures 1A-1B or flow restrictor 38 in Figures 2A-2B. "UT" refers to another prior art catheter assembly. HemoShield 1 was used in a hemolysis test using a 24G IAG; without a flow restrictor, all samples were hemolyzed (as measured by the presence of plasma free hemoglobin). With HemoShield 1, hemolysis was reduced to the level of UT 21G.

[0042] All examples and conditional statements incorporated herein are for educational purposes to aid the reader in understanding the concepts contributed by the inventor to further the present invention and technology, and should not be construed as being limited to such specifically incorporated examples and conditions. Although embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and alterations can be made therein without departing from the spirit and scope of the present invention.

Claims

1. 1. A blood collection device comprising: a syringe having a distal end; and a flow restrictor having a distal end and a proximal end, the proximal end being coupled to the distal end of the syringe; Equipped with The geometric factor of the flow restrictor is represented by G f , where G f is (i) 1.43E7 1 / in 3 ±30% (8.73E5 1 / cm 3 ±30%); (ii) 3.70E6 1 / in 3 ±30% (2.26E5 1 / cm 3 ±30%); (iii) 1.43E7 1 / in 3 ~3.70E6 1 / in 3 (8.73E5 1 / cm 3 ~2.26E5 1 / cm 3 ); (iv) 1.43E7 1 / in 3 ±10% (8.73E5 1 / cm 3 ±10%); or (v) 3.70E6 1 / in 3 ±10% (2.26E5 1 / cm 3 ±10%) a blood collection device, the blood collection device being at least one of:

2. The blood collection device of claim 1 , wherein the distal end of the flow restrictor is configured to couple to a catheter assembly.

3. 2. The blood collection set of claim 1, wherein the distal end of the syringe comprises a first luer adapter and the proximal end of the flow restrictor comprises a second luer adapter coupled to the first luer adapter.

4. 4. The blood collection device of claim 3, wherein the flow restrictor is monolithically formed as a single unit.

5. The blood collection device of claim 4 , wherein the distal end of the flow restrictor comprises a third luer adapter.

6. 4. The blood collection device of claim 3, wherein the distal end of the flow restrictor comprises a third luer adapter, and the flow restrictor further comprises an extension tube disposed between the second luer adapter and the third luer adapter.

7. 7. The blood collection device of claim 6, wherein the flow restrictor comprises a first piece monolithically formed as a single unit and a second piece monolithically formed as a single unit, the proximal end of the extension tube being integrated within the first piece, the distal end of the extension tube being integrated within the second piece, the first piece comprising the second luer adapter, and the second piece comprising the third luer adapter.

8. G f is 1.43E7 1 / in 3 2. The blood collection device of claim 1, wherein the density is 8.73E5 1 / cm<3> ±30% (8.73E5 1 / cm<3> ±30%).

9. G f is 3.70E6 1 / in 3 2. The blood collection device of claim 1, wherein the density is 2.26E5 1 / cm 3 ±30%.

10. The blood collection system 1. A catheter assembly comprising: a catheter adapter; a catheter extending distally from the catheter adapter; and 10. The blood collection device of claim 1 coupled to the catheter assembly. A blood collection system comprising:

11. 11. The blood collection system of claim 10, wherein the catheter assembly further comprises an extension tube, a distal end of the extension tube being integral with the catheter adapter, and the blood collection device being coupled to a proximal end of the extension tube.

12. 11. The blood collection system of claim 10, wherein the distal end of the syringe comprises a first luer adapter and the proximal end of the flow restrictor comprises a second luer adapter coupled to the first luer adapter.

13. The blood collection system of claim 12 , wherein the flow restrictor is monolithically formed as a single unit.

14. The blood collection system of claim 13 , wherein the distal end of the flow restrictor comprises a third luer adapter.

15. 13. The blood collection system of claim 12, wherein the distal end of the flow restrictor comprises a third luer adapter, and the flow restrictor further comprises an extension tube disposed between the second luer adapter and the third luer adapter.

16. 16. The blood collection system of claim 15, wherein the flow restrictor comprises a first piece monolithically formed as a single unit and a second piece monolithically formed as a single unit, wherein a proximal end of the extension tube is integrated within the first piece, a distal end of the extension tube is integrated within the second piece, the first piece comprising the second luer adapter, and the second piece comprising the third luer adapter.

17. G f 2. The blood collection device of claim 1, wherein the density is between 1.43E7 1 / in 3 and 3.70E6 1 / in 3 (8.73E5 1 / cm 3 and 2.26E5 1 / cm 3 ).

18. G f is 1.43E7 1 / in 3 2. The blood collection device of claim 1, wherein the density is 8.73E5 1 / cm<3> ±10% (8.73E5 1 / cm<3> ±10%).

19. The blood collection device of claim 1, wherein G f is 3.70E6 1 / in 3 ±10% (2.26E5 1 / cm 3 ±10%).

20. A blood collection device as described in claim 1, wherein the flow restrictor defines a fluid path from the proximal end to the distal end, the fluid path having a uniform inner diameter.

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