Infusion site for improved mixing of fluids
11738132 · 2023-08-29
Assignee
Inventors
Cpc classification
A61M1/3653
HUMAN NECESSITIES
A61M1/3458
HUMAN NECESSITIES
A61M1/342
HUMAN NECESSITIES
A61M1/3437
HUMAN NECESSITIES
A61M2202/0021
HUMAN NECESSITIES
A61M1/024
HUMAN NECESSITIES
A61M25/0074
HUMAN NECESSITIES
A61M2025/0031
HUMAN NECESSITIES
A61M2206/16
HUMAN NECESSITIES
A61M1/3627
HUMAN NECESSITIES
A61M1/3659
HUMAN NECESSITIES
A61M1/34
HUMAN NECESSITIES
International classification
A61M1/36
HUMAN NECESSITIES
Abstract
The present disclosure relates to a blood line (108) comprising an infusion site (145) intended to inject into the line a solution comprising: —a first main channel (200) having a first passage section, —a second main channel (220) having a second passage section, —means for the formation (210) of a turbulence area located downstream from the first main channel, located upstream from the second main channel, these formation means comprising a first fluid passage means (224) defining a reduction (225) in the passage section and whose smallest passage section is smaller than the first passage section and smaller than the second fluid passage section, —a secondary channel (230) comprising an inlet (231) for letting in the solution and an outlet (232) in fluid communication with the first main channel or the means for the formation of a turbulence area or the second main channel.
Claims
1. An extracorporeal circulation blood or plasma treatment device with local anticoagulation including: a filter having a first compartment and a second compartment separated by a semipermeable membrane; an arterial line in fluid communication with the first compartment of the filter; a pre-infusion channel for a local anticoagulation substance in fluid communication with the arterial line; a container of a local anticoagulation substance in fluid communication with the pre-infusion channel; a venous blood line in fluid communication with the first compartment of the filter, the venous blood line including: a first line portion in fluid communication with an outlet of the filter, a second line portion in fluid communication with a patient's vascular access, an infusion site between the first line portion and the second line portion for injecting into the blood line a solution reestablishing blood or plasma ion balance, the infusion site comprising: a first main channel in fluid communication with the first line portion and having a first passage section, a second main channel in fluid communication with the second line portion and having a second passage section, and a turbulence area downstream from and in fluid communication with the first main channel, and upstream from and in fluid communication with the second main channel, the turbulence area comprising a first fluid passage defining a reduction in passage section having a smallest passage section smaller than the first passage section and smaller than the second passage section, and a secondary channel comprising an inlet for the solution reestablishing blood or plasma ion balance and an outlet in fluid communication with at least one of the first main channel, the turbulence area and the second main channel; and a container of solution reestablishing blood or plasma ion balance in fluid communication with the secondary channel of the infusion site via a post-infusion line; and a central processing unit configured to: a) flow blood or plasma through the arterial line, b) infuse the local anticoagulation substance through the pre-infusion channel into the arterial line, c) filter blood through the filter, d) flow the filtered blood through the first line portion of the venous blood line, e) flow the filtered blood in the turbulence area of the infusion site to cause a turbulence in blood flow, f) infuse the solution for reestablishing ion balance through the secondary channel of the infusion site, and g) flow the filtered blood mixed with the solution for reestablishing blood or plasma ion balance through the second portion of the blood line, wherein step f) is carried out directly before, during or directly after step e).
2. The device of claim 1, wherein the post-infusion line is internally mounted into the secondary channel, an outer surface of the post-infusion line portion being sealingly connected to an inner surface of a post-infusion passage section of the infusion site.
3. The device of claim 1, wherein the first line portion is internally mounted into the first main channel of the infusion site and the second line portion is internally mounted into the second main channel of the infusion site.
4. The device of claim 1, wherein the turbulence area includes an elbow-shaped pipe.
5. The device of claim 4, wherein the longitudinal axis of the secondary channel of the site is perpendicular to the longitudinal axis of the second main channel of the site, the longitudinal axis of the first main channel of the site being parallel to the longitudinal axis of the second main channel of the site.
6. The device of claim 1, wherein the turbulence area comprises a secondary inlet and the outlet of the secondary channel of the infusion site is connected to the secondary inlet, the outlet of the secondary channel is in fluid communication with the turbulence area.
7. The device of claim 1, wherein the local anticoagulation substance includes citrate and the solution reestablishing blood or plasma ion balance includes calcium.
8. The device of claim 1, wherein the longitudinal axis of the secondary channel of the site for letting in a solution reestablishing ion balance is parallel to the longitudinal axis of the second main channel of the infusion site.
9. The device of claim 1, wherein a pipe for injecting the solution reestablishing blood or plasma ion balance has a constant circular section, the constant circular section of the pipe being smaller than any of the sections of the first main channel and the second main channel.
10. The device of claim 1, wherein the diameter of an outlet of the secondary channel of the infusion site is equal to or less than 0.8 mm.
11. The device of claim 1, wherein the turbulence area includes a second fluid passage downstream from the first fluid passage, the second fluid passage defining a fluid passage increase, and wherein a largest fluid passage section of the second fluid passage is smaller than the first passage section and smaller than the second passage section, the fluid passage increase in the fluid passage section of the second fluid passage defining a shoulder perpendicular to the longitudinal axis of the second fluid passage.
12. The device of claim 1, wherein the first fluid passage of the turbulence area defines a continuous section narrowing fluid passage.
13. The device of claim 1, wherein the first fluid passage of the turbulence area has a constantly narrowing internal circular section, resulting in a conical internal surface having a symmetrical axis, which is the longitudinal axis of the first passage.
14. The device of claim 13, wherein the Reynolds number for blood flow in the smallest circular section of the conical internal surface varies from 350 to 3,000.
15. The device of claim 13, wherein the Reynolds number for blood flow in the smallest circular section of the conical internal surface varies from 500 to 2,000.
16. The device of claim 13, wherein a ratio between the largest circular section of the conical internal surface and the smallest circular section of the conical internal surface is less than 3.6:1.
17. The device of claim 13, wherein the diameter of the smallest circular section of the conical internal surface is equal to or less than 1.2 mm.
18. The device of claim 1, wherein the inner diameter of the post-infusion line where the solution at least partially reestablishes blood ion balance is equal to the diameter of an outlet of the secondary channel of the infusion site.
19. The device of claim 1, wherein a ratio between a diameter of the smallest passage section of the first fluid passage and a diameter of the first passage section is less than about 30%.
20. The device of claim 1, wherein the inlet of the secondary channel of the infusion site is tapered.
21. The device of claim 1, wherein the secondary channel section interposed between the inlet and the outlet has a constant circular section.
22. The device of claim 1, wherein the container of solution reestablishing blood or plasma ion balance is a bag or a syringe.
23. The device of claim 1, wherein the treatment device includes a bubble trap located along the venous blood line upstream from the infusion site.
24. The device of claim 1, wherein the treatment device includes an air detector operating with the venous blood line downstream from the infusion site.
25. The device of claim 1, wherein the turbulence area operates in a blood flow range between 50 ml/min and 350 ml/min.
26. The device of claim 1, wherein the container of solution reestablishing ion balance is connected to the secondary channel of the infusion site via a post-infusion line, the first line portion being internally mounted into the first main channel, the second line portion being internally mounted into the second main channel and the post-infusion line being internally mounted into the secondary channel.
27. The device of claim 1, wherein the turbulence area is configured for creating a turbulent flow in a blood flow range between 50 ml/min and 200 ml/min.
28. An extracorporeal circulation blood or plasma treatment device with local anticoagulation including a set of lines configured to be in fluid communication with a blood or plasma filter, comprising: an arterial line having a connector configured to be in fluid communication with the first compartment of a filter; a pre-infusion channel for a local anticoagulation substance in fluid communication with the arterial line; a container of local anticoagulation substance in fluid communication with the pre-infusion channel; a venous blood line for extracorporeal blood or plasma treatment comprising: (i) a first line portion configured to be in fluid communication with an outlet of the filter, and (ii) a second line portion configured to be in fluid communication with a patient's vascular access, a bubble trap; and a container of solution reestablishing ion balance, wherein the venous blood line further comprises: an infusion site between the first line portion and the second line portion for injecting into the blood line a solution reestablishing blood or plasma ion balance, the infusion site comprising: a first main channel in fluid communication with the first line portion and having a first passage section, a second main channel in fluid communication with the second line portion and having a second passage section, a turbulence area downstream from and in fluid communication with the first main channel, and upstream from and in fluid communication with the second main channel, the turbulence area comprising a first fluid passage defining a reduction in the passage section having a smallest passage section smaller than the first passage section and smaller than the second fluid passage section, and a secondary channel comprising an inlet for a solution reestablishing ion balance and an outlet in fluid communication with at least one of the first main channel, the turbulence area and the second main channel, wherein an inlet of the first line portion is configured to be in fluid communication with the outlet of the filter and an outlet of the second line portion is configured to be in fluid communication with a patient's vascular access, the bubble trap being on the first line portion of the line upstream or downstream from the infusion site, and the container of solution reestablishing ion balance being in fluid communication with the secondary channel of the infusion site.
29. The device of claim 28, further comprising a central processing unit configured to: a) flow blood or plasma through the arterial line, b) infuse the local anticoagulation substance through the pre-infusion channel into the arterial line, c) filter blood through the filter, d) flow the filtered blood through the first line portion of the venous blood line, e) flow the filtered blood in the turbulence area of the infusion site to cause a turbulence in blood flow, f) infuse the solution for reestablishing ion balance through the secondary channel of the infusion site, and g) flow the filtered blood mixed with the solution for reestablishing blood or plasma ion balance through the second portion of the blood line, wherein step f) is carried out directly before, during or directly after step e).
Description
BRIEF DESCRIPTION OF THE FIGURES
(1) We shall make reference to the attached drawings, wherein:
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DETAILED DESCRIPTION OF THE PRESENT DISCLOSURE
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(14) It should be noted that
(15)
(16) The infusion site 145 is intended to receive a post-infusion line 112 for a solution at least partially reestablishing blood ion balance and is in fluid communication with the second channel 137 and in fluid communication with the channel 134. The line further includes a first portion 141 of the second channel 137 that is able to cooperate with the air detector 113 and placed downstream from the site 145. The first portion 141 is optically coded, e.g. with different colors, with a relief, with a pipe having a different material, shape or size with respect to the remaining line. The above described elements of the line are not strictly necessary for implementing the invention, either.
(17)
(18) However, as an alternative to the configuration of
(19) As shown on each of the
(20) The assembly of the channels with the infusion site is not shown in
(21) In order to optimize the mixing homogeneity of blood and calcium, the geometry of the infusion site has been given the first place so as to enable the formation of a blood turbulence area integrated into the blood flow area. Indeed, it is important to increase the number of Reynolds so as to ensure the switch from a laminar flow to a turbulent flow in the injection site, which means homogenization of the two liquids and prevents local coagulation due to an inaccurate mixing.
(22) According to the invention, blood reaches this flow rate in the infusion site and should be able to get out of it with the same flow rate per hour, and preferably substantially the same linear flow rate (ml/mm) after getting through the turbulence area (the smallest infusion flow rate as possible is added to the inlet flow rate).
(23) A turbulence area is an area in which fluid flow becomes instable and perturbed, thus generating multiple whirlpools. The turbulent flow is opposed to the laminar flow. Reducing the passage section in the infusion site enables to increase the number of Reynolds to a sufficient degree so as to switch from a laminar to a turbulent flow, so as to generate a turbulence, though leaving hemoglobin untouched and ensuring the prescribed blood flow rate. As a matter of fact, it should be noted that hemoglobin, more precisely red corpuscles, are not damaged during treatment, which enables to prevent a hemolysis that might be fatal to the patient. Moreover, the blood flow rate should keep a given threshold in order to prevent the treatment from getting longer.
(24) Therefore, the solution enabling to reestablish ion balance (e.g. calcium) is injected directly close to the turbulence formation area. The turbulence formation area gets integrated into the disposable blood line. Once more, turbulence intensity is optimized so as to ensure at the same time a sufficient mixing and to prevent a significant hemolysis in the expected operating range.
(25) The comparative tests on the infusion site according to the invention show highly positive results since the mix is homogenized without altering any other treatment parameters. As a matter of fact, calcium infusion close to the blood turbulence area inhibits the long threads of fibrins observed on a prior art infusion site and no clots are observed, either. Tests have been carried out by periodically monitoring coagulation time (APTT) and calcium, sodium and potassium as well as pH.
(26) The turbulence area formation means (210) can comprise a secondary inlet (213), and the outlet (232) of the secondary channel of the site (230) is connected to said secondary inlet (213).
(27) Alternatively, the first main channel (200) can include a secondary inlet (shown schematically by arrow 3 in
(28) Still alternatively, the second main channel (220) includes a secondary inlet (shown schematically by the arrows “1” and “1′” in
Continuous Section Narrowing
(29) Moreover, the first fluid passage means (224) of the turbulence area formation means (210) can define a continuous section narrowing in the sense of fluid passage. More particularly, the first fluid passage means (224) of the turbulence area formation means (210) defined a constant narrowing of internal circular section, thus resulting in an internal conical surface of revolution whose symmetry axis is the longitudinal axis of the 10 first passage means. It has been shown that a constant, smooth, continuous and preferably progressive narrowing enables not to limit hemolysis intensity. The number of Reynolds in the surface of the smallest circular section (228) of the conical surface can be chosen depending of the expected operating range of the device. The number of Reynolds for a blood passage in the smallest circular section of the conical surface (228) can vary from about 500 to about 2,000.
Operating Range
(30) The number of Reynolds is chosen so as to obtain a compromise between homogeneous mixing and hemolysis prevention as a function of the blood flow rate range. The development of the number of Reynolds in section “g” for the two sizes of the components (calculation for a viscosity of 3 cP) is shown in the following table:
(31) TABLE-US-00001 Blood flow rate High flow version (FIGS. Low flow version ml/min. 5, 6 and 7) (FIGS. 9 and 10) 50 442 75 663 100 590 880 150 880 1,330 20 1,180 1,770 250 1,470 300 1,770 350 2,060
(32) However, this table should not be deemed as limiting. The number of Reynolds can vary in the range [350, 3,000), preferably in the range [500, 2,000].
(33) Furthermore, as is still shown in at least
(34) Generally speaking,
(35) In
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(39) Each mode can be combined with another one for obtaining a further embodiment of the site.
Partial Separation(s)
(40) Alternatively, the line according to the invention can have the first fluid passage means (224) of the turbulence area formation means (220) comprising at least a partial separation (250) whose longitudinal plane is perpendicular to the longitudinal axis of the first passage means (224). This is shown in
(41) The turbulence area formation means (220) can comprise at least two partial separations (250) each longitudinal plane of which is perpendicular to the longitudinal axis of the first fluid passage means (224), divided according to a symmetry point located on said longitudinal axis. The mode including two partial separations is shown in
(42) In
(43) More particularly, the secondary channel (230) for letting in the ion reestablishing solution in the site (145) can be integrated into one of the partial separations (250) and where the axis of the secondary channel is perpendicular to the longitudinal axis of the first fluid passage means (224).
(44) It should be noted in general for all embodiments that injected calcium is not perturbed before its arrival in the main channel and that calcium is preferably let in by a pipe with a constant circular section, preferably with a smaller section than the one of the first and second main channels.
(45) According to the invention, the turbulence area formation means (210) can be an elbow pipe or a straight pipe.
(46) Moreover, the outlet of the secondary channel (230) of the infusion site is connected to the secondary inlet of the turbulence area formation means (210), this secondary inlet (232) being located on the second fluid passage means (224).
Distribution of Axes
(47) According to the invention: the longitudinal axis of the secondary channel (230) of the site for letting in a solution reestablishing ion balance can be parallel to, preferably coaxial with the longitudinal axis of the second main channel of the site, the longitudinal axis of the secondary channel (230) of the site can be perpendicular to the longitudinal axis of the second main channel (220) of the site, the longitudinal axis of the first main channel (200) of the site can be perpendicular to the longitudinal axis of the second main channel (220) of the site, the longitudinal axis of the first channel (200) of the site can be parallel to, preferably coaxial with the longitudinal axis of the second main channel (220) of the site, the respective axes of the first (210) and of the second (220) main channel of the site and of the secondary channel (230) of the site can be coplanar, the longitudinal axis of the end of the first line portion (134) connected to the site is coaxial with the longitudinal axis of the first main channel (200) of the site, the longitudinal axis of the end of the second line portion (137) connected to the site is coaxial with the longitudinal axis of the second main channel (200) of the site.
(48) The above generally implies that the inlet and outlet of each channel are included in the axis.
(49) Furthermore, the invention can comprise the following elements: the secondary channel (230) of the infusion site is connected to a bag or a syringe (133) containing liquid for reestablishing ion balance, the line comprises a bubble trap (111) acting on the first line portion (134) preferably upstream (possibly downstream) from the infusion site (145), the infusion site (145) is made as one piece, the infusion site (145) is made of rigid or semi-rigid hemocompatible plastic material, preferably starting from polyethylene terephthalate (PETG) or polytetrafluoroethylene (PTFE—Teflon), Dacron (polyester), PVC.
(50) Moreover, the set of lines according to the invention, as well as the device for blood treatment according to the invention, can further include: a container for local anticoagulation substance connected to the pre-infusion channel (109), and/or a container for solution reestablishing ion balance 133 (e.g. a bag, a syringe and so on) connected to the secondary channel (230) of the infusion site.
(51) All lines can be disposable, the blood device too.
(52) The blood treatment device according to the invention can further comprise one and/or the other of the following elements: a drain channel (110) getting out of the second compartment (104) of the filter (102), a container of local anticoagulation substance connected to the pre-infusion channel (109), a container of solution reestablishing ion balance (133) connected to the secondary channel (230) of the infusion site, an air detector (113) acting on the blood line downstream from the infusion site (145), an air separator (111) on the blood line (108), upstream from the air detector.
(53) By way of information, the infusion site shown in
(54) TABLE-US-00002 High flow version (e.g. Low flow version (e.g. FIGS. Side FIGS. 5, 6 and 7) 9 and 10) a 6.55 4.75 b 4.15 2.87 c 3.18 3.18 d 0.80 0.80 e 9 9 f 6 6 g 1.2 0.8
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Advantages of the Invention
(56) The invention has several advantages: the device enables to homogenize blood and calcium injected, thus preventing any formation of local coagulation (generally observed as filament), it requires no additional component normally used in the extracorporeal blood circuit, the reestablishing solution (calcium in particular) is mixed with blood in a homogeneous manner and blood is not damaged by the turbulence area, the turbulence formation area is integrated into the disposable blood line: this is no additional means or a means independent from the extracorporeal circuit and it is not strictly necessary to use a syringe.