GB1601855A

GB1601855A - Dialysis apparatus

Info

Publication number: GB1601855A
Application number: GB12898/78A
Authority: GB
Original assignee: Baxter Travenol Laboratories Inc
Current assignee: Baxter International Inc
Priority date: 1977-05-09
Filing date: 1978-04-03
Publication date: 1981-11-04
Also published as: CA1104032A; DE2820256A1; JPS53139399A; FR2390173A1; GB1601856A

Description

(54) DIALYSIS APPARATUS (71) We, BAXTER TRAVENOL LABORA TORIES INC., a Corporation organised and existing under the laws of the State of Delaware, United States of America, of One Baxter Parkway, Deerfield, Illinois 60015, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: Hemodialysis apparatus for artificial kidneys generally comprises a supported, semipermeable membrane made of a Cellophanelike material (Registered Trade Mark), positioned in a casing to provide a blood flow path along one side of the membrane and a dialysis solution flow path along the other side, for diffusion exchange across the membrane between the blood and the dialysis solution without the direct intermixing of the two liquids.

In the actual hemodialysis process, a considerable number of processing steps are required during the operation of bringing the blood to the hemodialyzer, and withdrawing it from the hemodialyzer for return to the patient. In the presently-conventional arterial and venous sets which are used to withdraw blood from a patent, convey it to the dialyzer, and return it again to the patient, bubble traps, filters, sterile access sites for injection needles, and access sites for pressure monitor equipment may all be included on the sets, which primarily comprise flexible, blood compatible plastics tubing. Accordingly, in the present technology of dialysis, two different and separate long, tubular sets are utilized, the arterial set upstream from the dialyzer in terms of blood flow, and the venous set downstream from the dialyzer.

Hence, to set up a dialysis procedure, a dialyzer must be selected, and the nurse must also separately obtain an arterial set and a venous set. The packaging of all of these devices must be opened, and the devices respectively must be connected and assembled together, with other auxiliary equipment being also added to the system.

This requires the services of a highly trained technician, who must make a considerable number of connections between the sets and the dialyzer, flawlessly and without error.

As described hereinafter, a one-piece hydraulic circuit member is provided to replace many of the functions of the arterial inlet and outlet sets, and auxiliary equipment. The one-piece hydraulic member may be connected to the dialyzer itself at the time of manufacture, if desired, The set-up of the dialysis system prior to use is thus greatly simplified, eliminating many of the connections which must be made by the technician at the site of use, which, in turn, reduces the possibility of error, and contamination of the system during the assembly and connection process. Furthermore, the system is compact and simplified, saving a considerable amount of valuable space around the bed during the dialysis procedure. A part of the member serves as a bubble trap for preventing air bubbles being passed to a patient in the blood.

In accordance with this invention there is provided a rigid unitary hydraulic circuit member for use with a membrane diffusion device and formed with a plurality of bloodreceiving chambers, for directing, receiving, and processing blood passing through said membrane diffusion device, in which at least one of said blood receiving chambers has a transversely-enlarged upper chamber portion connected by a step wall which abruptly narrows the bottom end of said enlarged chamber area to a lower chamber portion of lesser transverse dimensions, and points of communication of said conduit means with said chamber, including an inlet spaced from the bottom of said chamber and communicating directly with said enlarged upper chamber portion in an upwardly- pointing direction through said step wall, and an outlet positioned adjacent the end of said lower portion remote from said enlarged, upper portion of said chamber, said chamber defining venting means for gases at its upper end and serving as a bubble trap for blood when blood is introduced through said inlet and withdrawn through said outlet.

One of the chambers may include an airblocking filter to assist in preventing infusion of air into the patient.

Additionally, injection-type access sites, for example, for removal of air, may be provided, as well as a site for measuring chamber pressure. Also, a saline infusion and heparin line may be added to the device where desired.

In the drawings, Figure 1 is a perspective view of one embodiment of a hydraulic circuit member according to this invention connected to a hollow fiber-type dialyzer, and further connected to auxiliary tubing of various types; Figure 2 is a transverse sectional view of the hydraulic circuit member taken along line 2-2 of Figure 1; Figure 3 is a similar transverse sectional view of another embodiment of a hydraulic circuit member according to this invention Figure 4 is a detailed sectional view of an alternative sensing member as a replacement for member 80 in Figure 1; and Figure 5 is a sectional view taken along line 5-5 of Figure 1.

Referring to the drawings, hydraulic circuit member 10 is a sterile member comprising a rigid, flat member made of bloodcompatible plastics material, and defining chambers 12, 14 and 16 within the plastics piece.

As shown in Figure 2, the member 10 comprises a lower flat plastics plate 18 which has cut-out portions defining the chambers and ports. Plastics plate 18 is sealed by a cover member 20 to close said cutout portions.

Alternatively, as in Figure 3, both plastics plate 1 8a and cover 20a may be equallysized pieces, both defining cutout portions for chambers 12, 14 and 16, and for the various ports.

Chamber 12 may preferably include a blood filter member 22, surrounding a first port or conduit 24, which, in turn, provides communication between chamber 12 and flexible tubing 26, adapted for communication with the vein of a patient. In any conventional manner, venous tubing 26 may contain a sterile injection site 28 for blood sampling or medication, clamp 30, and removable sterile cover 32 for sealing the tubing. Tubing 26 may be connected to a fistula needle for access to the patient, or an arteriovenous shunt, or any other desired means for communication with the patient's venous system.

Chamber 12 also defines a second port or conduit 34 which is shown to define an elongated channel for communication with a blood outlet conduit 36, receiving blood from the blood of dialyzer 38. Dialyzer 38 is shown to be a commercially available hollow fiber dialyzer in this particular embodiment, although this invention may be used with any type of dialyzer.

Accordingly, blood outflow from the dialyzer 38 enters chamber 12 at an upper end, and passes through filter 22 into venous line 26 for reinfusion to the patient.

Second chamber 14 is in communication through port or conduit 40 with blood tubing 42, which may be in communication with the arterial system of a patient. Tubing 42 also may carry a conventional injection site 28, clamp 30, and sterile cover 32, as well as any other conventional equipment. Also, if desired, tubings 26 and 42 may be integrally connected together by a fine web 44 of plastics material, which may be torn apart as far along the length of the respective tubings 26, 42 as desired, but otherwise which holds the two tubings together in an integral manner, to avoid the confusing and inconvenient separate wandering and coiling of the respective tubes.

Tubes 26 and 42 may be conveniently coextruded as a single piece to define the frangible web 44 between them. Appropriate indicia such as coloured lines 46, 48 may be placed on the respective tubing 26, 42 for identification of the tubing.

Blood from tubing 42 passes through third port 40, to an entry point in a step wall 50 which, as shown in Figure 1, abruptly narrows the bottom of the chamber 14, being intermediate along the length of chamber 14, to provide an upper area 52 in the chamber which is relatively enlarged for receiving and retaining gas bubbles. This entry point, or inlet, is, therefore, spaced from the bottom of the chamber, and, as shown, the inlet communicates with the upper chamber portion 52 in an upwardly-pointing direction.

The blood then is withdrawn from chamber 14 downwardly from the lower end through a fourth port or conduit 54 which, in turn, is in communication with a length of blood pump tubing 56. Tubing 56 may be emplaced within a roller-type blood pump for movement of the blood from chamber 14 to chamber 16, and to power the blood flow through the entire system.

If desired, saline solution infusion line 58, controlled by clamp 60, may communicate in sterile manner with port 54 for use as desired.

The blood from tubing 56 enters fifth port or conduit 62, which leads to chamber 16, communicating with the chamber at a midpoint thereof in a manner similar to entry point 50, and for the similar purpose of providing a bubble-trapping capability to the chamber.

Blood is withdrawn from chamber 16, impelled by the action of a blood pump on tubing 56, through the sixth port or conduit 64, which, in turn, communicates with an inlet line 66 leading into the blood inlet of the dialyzer 38.

A heparin administration line 70 may be provided in communication with port 62 if desired, carrying a sterile end seal 72 for connection with any desired heparin administration device for administering measured quantities of heparin over a period of time to the blood circuit Accordingly, blood enters from the patient's arterial system through tubing 42, passing through port 40 to chamber 14 for bubble removal, and from there to pump tubing 56 through port 54.

Impelled by the blood pump, the blood is forced onwardly through port 62 into chamber 16 for additional bubble removal, and from there through port 64 into the dialyzer 38. Dialyzed blood passes along port 34 into chamber 12. Then, the blood passes through filter 22, through port 24, and into venous tubing 26 for return to the patient.

Gripper members 74 are carried by hydraulic circuit member 10 for grasping, as shown, the dialyzer 38, to provide a convenient, one-piece structure including both the dialyzer and much of its circuitry. The entire structure may have a hanger or attachment member (not shown) for hanging or clamping on an IV pole or the like as desired.

Each of the chambers 12, 14, 16 defines an upper projecting channel 76. Connected to this channel in each case is a sealed injection site member 78, which may include a latex member compression fitted into a tubular member in a manner similar to the injection site members which are in present commercial use on the arterial and venous sets for dialysis sold by the Artificial Organs division of Travenol Laboratories, Inc., Deerfield, Illinois. Excess air trapped in the chambers may be removed by a needle and syringe through site 78.

Tubing 80 is also in communication with upper projecting channel 76 in each case.

Sealed end 81 may be opened and connected to a manometer or other pressure measuring device to obtain a direct measurement of the pressure within chambers 12, 14 or 16.

Clamp 82 is also provided to seal tubing 80 when not in use. As an alternative structure to replace tube 80 with its direct connection to each of the chambers 12, 14 or 16, a pressure-sensing member 84 may be provided which measures the pressure of the respective chambers in a non-invasive manner.

As shown in Figure 4, pressure-sensing member 84 comprises a housing 86 which fits over an aperture 88 in part of the wall of hvdraulic circuit member 10 which is in communication with channel 76. A liquidimpermeable, flexible diaphragm 90 is positioned across aperture 88, positioned in the effective sensing range of a transducer 92, which is adapted to sense the degree of outward or inward bulging of diaphragm 90, in response to positive or negative pressure in the channel 76.

Accordingly, the pressure within each of chambers 12, 14, 16 is reflected by the degree of outward or inward bulging of diaphragm 90. This, in turn, is sensed by transducer 92 and communicated along electrical line 94 to a conventional readout device so that, as desired, the pressure in the respective chambers 12, 14 and 16 can be monitored, while the system remains sealed.

WHAT WE CLAIM IS:- 1. A rigid unitary hydraulic circuit member for use with a membrane diffusion device and formed with a plurality of bloodreceiving chambers, and with conduit means communicating between said bloodreceiving chambers, for directing, receiving, and processing blood passing through said membrane diffusion device, in which at least one of said blood receiving chambers has a transversely-enlarged upper chamber portion connected by a step wall which abruptly narrows the bottom end of said enlarged chamber area to a lower chamber portion of lesser transverse dimensions, and points of communication of said conduit means with said chamber, including an inlet spaced from the bottom of said chamber and communicating directly with said enlarged upper chamber portion in an upwardly- pointing direction through said step wall, and an outlet positioned adjacent the end of said lower portion remote from said enlarged, upper portion of said chamber, said chamber defining venting means for gases at its upper end and serving as a bubble trap for blood when blood is introduced through said inlet and withdrawn through said outlet.

2. A hydraulic circuit member according to Claim 1, which comprises a flat plastics plate having the chambers and conduits defined by cut-out portions in the plate, and a cover member sealed to the plate and closing said cut-out portions.

3. A hydraulic circuit member according to Claims 1 or 2 in which said chamber serving as a bubble trap has an aperture sealed by a liquid-impermeable, flexible diaphragm, pressure sensing means being provided adjacent said diaphragm outside of said chamber, whereby displacement of said diaphragm in response to pressure in said chamber is sensed by said pressure sensing means.

4. A hydraulic circuit member for use with a blood dialyzer in which first second and third chambers are present in said unit

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. tubing 56, through the sixth port or conduit 64, which, in turn, communicates with an inlet line 66 leading into the blood inlet of the dialyzer 38. A heparin administration line 70 may be provided in communication with port 62 if desired, carrying a sterile end seal 72 for connection with any desired heparin administration device for administering measured quantities of heparin over a period of time to the blood circuit Accordingly, blood enters from the patient's arterial system through tubing 42, passing through port 40 to chamber 14 for bubble removal, and from there to pump tubing 56 through port 54. Impelled by the blood pump, the blood is forced onwardly through port 62 into chamber 16 for additional bubble removal, and from there through port 64 into the dialyzer 38. Dialyzed blood passes along port 34 into chamber 12. Then, the blood passes through filter 22, through port 24, and into venous tubing 26 for return to the patient. Gripper members 74 are carried by hydraulic circuit member 10 for grasping, as shown, the dialyzer 38, to provide a convenient, one-piece structure including both the dialyzer and much of its circuitry. The entire structure may have a hanger or attachment member (not shown) for hanging or clamping on an IV pole or the like as desired. Each of the chambers 12, 14, 16 defines an upper projecting channel 76. Connected to this channel in each case is a sealed injection site member 78, which may include a latex member compression fitted into a tubular member in a manner similar to the injection site members which are in present commercial use on the arterial and venous sets for dialysis sold by the Artificial Organs division of Travenol Laboratories, Inc., Deerfield, Illinois. Excess air trapped in the chambers may be removed by a needle and syringe through site 78. Tubing 80 is also in communication with upper projecting channel 76 in each case. Sealed end 81 may be opened and connected to a manometer or other pressure measuring device to obtain a direct measurement of the pressure within chambers 12, 14 or 16. Clamp 82 is also provided to seal tubing 80 when not in use. As an alternative structure to replace tube 80 with its direct connection to each of the chambers 12, 14 or 16, a pressure-sensing member 84 may be provided which measures the pressure of the respective chambers in a non-invasive manner. As shown in Figure 4, pressure-sensing member 84 comprises a housing 86 which fits over an aperture 88 in part of the wall of hvdraulic circuit member 10 which is in communication with channel 76. A liquidimpermeable, flexible diaphragm 90 is positioned across aperture 88, positioned in the effective sensing range of a transducer 92, which is adapted to sense the degree of outward or inward bulging of diaphragm 90, in response to positive or negative pressure in the channel 76. Accordingly, the pressure within each of chambers 12, 14, 16 is reflected by the degree of outward or inward bulging of diaphragm 90. This, in turn, is sensed by transducer 92 and communicated along electrical line 94 to a conventional readout device so that, as desired, the pressure in the respective chambers 12, 14 and 16 can be monitored, while the system remains sealed. WHAT WE CLAIM IS:-

1. A rigid unitary hydraulic circuit member for use with a membrane diffusion device and formed with a plurality of bloodreceiving chambers, and with conduit means communicating between said bloodreceiving chambers, for directing, receiving, and processing blood passing through said membrane diffusion device, in which at least one of said blood receiving chambers has a transversely-enlarged upper chamber portion connected by a step wall which abruptly narrows the bottom end of said enlarged chamber area to a lower chamber portion of lesser transverse dimensions, and points of communication of said conduit means with said chamber, including an inlet spaced from the bottom of said chamber and communicating directly with said enlarged upper chamber portion in an upwardly- pointing direction through said step wall, and an outlet positioned adjacent the end of said lower portion remote from said enlarged, upper portion of said chamber, said chamber defining venting means for gases at its upper end and serving as a bubble trap for blood when blood is introduced through said inlet and withdrawn through said outlet.

ary, rigid member, at least one of which is of the shape as defined in Claim 1, 2 or 3 and further including a first port, communicating with said first chamber and adapted for connection with a venous line of a patient, and a second port communicating with said first chamber and adapted for connection with the outlet of a blood dialyzer; a second chamber communicating with a third port, said third port being adapted for connection with an arterial line of a patient, said second chamber also communicating with a fourth port adapted for connection with blood pump tubing, and a third chamber communicating with a fifth port adapted for connection with said blood pump tubing, said third chamber also communicating with a sixth port adapted for connection with the inlet of said blood dialyzer.

5. A hydraulic circuit member according to Claim 4 in which said first chamber contains a blood filter positioned for filtering gases from the blood flow through said first port.

6. A hydraulic circuit member according to Claim 4 or 5 in which a saline infusion line is in communication with said fourth port.

7. A hydraulic circuit member according to Claim 4, 5 or 6 in which a heparin line is in communication with said fifth port.

8. A hydraulic circuit member according to Claim 4, 5, 6 or 7 in which a sealable injection site provides communication by means of an injection needle to said chambers.

9. A hydraulic circuit member according to any one of Claims 4 to 8 in which said first port is connected to a venous line and said third port is connected to an arterial line, said arterial and venous lines being joined together along one side of each along a major portion of their lengths.

10. A hydraulic circuit member according to any one of Claims 4 to 9 in which said third and fifth ports respectively communicate with the inlets in said second and third chambers while said fourth and sixth ports communicate respectively with said second and third chambers at the outlets.

11. A hydraulic circuit member according to Claim 10 in which said first port communicates with the lower end of said first chamber and said second port communicates adjacent the upper end of said first chamber.

12. A hydraulic circuit member for use with a blood dialyzer for directing and controlling blood flow the member being a rigid, unitary member defining spaced chambers for receiving blood and conduit means communicating with said chamber and adapted respectively for connection with a venous line of a patient, the blood inlet and outlet of a blood dialyzer, an arterial line for the patient, and ports for communication with blood pump tubing, in which at least some of the chambers defined within said rigid unitary member constitute blood-receiving chambers each defining a distinct, transversely-enlarged upper chamber portion connected by a step wall to a lower portion thereof which is of smaller transverse dimension, and points of communication of said conduit means with said chamber including a first point of communication spaced from the bottom of said chamber and communicating directly with said upper chamber portion in an upwardly-pointing direction through said step wall, and a second point of communication of said conduit means with said chamber being positioned adjacent the end of said lower portion remote from the upper portion of said chamber, and venting means provided at the top of said chamber, whereby bubble-trapping capabilities are provided to blood in said chamber which is introduced to the chamber through said first point of communication and withdrawn through said second point of communication.

13. A hydraulic circuit member constructed substantially as herein described with reference to the accompanying drawings.